2016 v11n7

IJSPT

INTERNATIONAL JOURNAL OF SPORTS PHYSICAL THERAPY

VOLUME ELEVEN issue sEVEN DECEMBER 2016

IJSPT

INTERNATIONAL JOURNAL OF SPORTS PHYSICAL THERAPY

Editor in Chief Michael L. Voight, PT, DHSc, OCS, SCS, ATC, CSCS Belmont University Nashville, Tennessee – USA

Associate Editors: John Dewitt PT, DPT, SCS, ATC The Ohio State University Sports Medicine Columbus, Ohio - USA

Senior Associate Editor Barbara Hoogenboom, PT, EdD, SCS, ATC Grand Valley State University Grand Rapids, Michigan - USA

Terry Grindstaff PhD, PT, ATC Creighton University Omaha, Nebraska - USA

Manuscript Coordinator Ashley Campbell, PT, DPT, SCS, ATC Associate Editor, Thematic Issues: Robert Manske, PT, DPT, Med, SCS, ATC, CSCS Wichita State University Wichita, Kansas – USA

International Associate Editors: Mario Bizzini, PT, MSc Schulthess Clinic Zürich – Switzerland Henning Langberg, PT, PhD, MSc Institute of Sports Medicine Copenhagen – Denmark

Editorial Board: Scott Anderson, PT, Dip Sport PT Northgate Physical Therapy Regina, Saskatchewan – Canada

Mark S. De Carlo, PT, DPT, MHA, SCS, ATC Accelerated Rehabilitation Indianapolis, Indiana – USA

Lindsay Becker, PT, DPT, SCS, CSCS The Ohio State University Sportsmedicine Center Columbus, Ohio – USA

Todd S. Ellenbecker, DPT, SCS, OCS Physiotherapy Associates Scottsdale Sports Clinic Scottsdale, Arizona – USA

Barton Bishop, PT, DPT, SCS, CSCS Sport and Spine Rehab of Rockville Rockville, Maryland – USA

John A. Guido, Jr., PT, MHS, SCS, ATC, CSCS Ochsner Health Systems New Orleans, Louisiana – USA

Turner A. “TAB” Blackburn, Jr., MEd, PT, ATC Clemson Sports Medicine and Rehabilitation Manchester, Georgia – USA

Elizabeth L. Harrison, PT, PhD, Dip Sport PT University of Saskatchewan Saskatoon, Saskatchewan – Canada

Lori A Bolgla, PT, PhD, MAcc, ATC Augusta University Augusta, Georgia – USA

Walter L. Jenkins, PT, DHS, ATC East Carolina University Greenville, North Carolina - USA

Robert J. Butler, PT, DPT, PhD Duke University Durham, NC – USA

Daniel S. Lorenz, PT, DPT, ATC, CSCS Providence Medical Center Kansas City, Kansas - USA

Duane Button, PhD, CSEP-CEP Memorial University St. John’s, Newfoundland and Labrador – Canada

Terry Malone, PT, EdD, ATC, FAPTA University of Kentucky Lexington, Kentucky – USA

Rick Clark, PT, DScPT, CCCE Air Force Academy Colorado Springs, CO – USA

Peter J. McNair, PT, PhD Auckland University of Technology Auckland – New Zealand

George J. Davies, PT, DPT, SCS, ATC, FAPTA Armstrong Atlantic State University Savannah, Georgia – USA

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Phil Page, PT, PhD, ATC, CSCS The Hygenic Corporation Akron, Ohio – USA

Timothy Uhl, PT, PhD, ATC University of Kentucky Lexington, Kentucky – USA

Mark Paterno, PT, PhD, MBA, SCS, ATC Cincinnati Children’s Hospital Medical Center Cincinnati, Ohio – USA

Mark D. Weber, PT, PhD, SCS, ATC University of Mississippi Medical Center Jackson, Mississippi – USA

Charles E. Rainey, PT, DSc, DPT, MS, OCS, SCS, CSCS, FAAOMPT United States Public Health Service Springfield, Missouri - USA

Kevin Wilk, PT, DPT Champion Sports Medicine Birmingham, Alabama – USA

Michael P. Reiman, PT, DPT, OCS, SCS, ATC, FAAOMPT, CSCS Duke University School of Medicine Durham, North Carolina – USA Mark F. Reinking, PT, PhD, SCS, ATC Saint Louis University St. Louis, Missouri – USA Jill Robertson, PT, MSc (PT), Dip Manip PT Beaverbank Orthopaedic and Sport Physiotherapy Halifax, Nova Scotia – Canada Kevin Robinson, PT, DSc, OCS Belmont University Nashville, Tennessee – USA Barbara Sanders, PT, PhD, SCS, FAPTA Texas State University-San Marcos San Marcos, Texas – USA Teresa L. Schuemann, PT, DPT, SCS, ATC, CSCS Colorado Physical Therapy Specialists Fort Collins, Colorado – USA Brandon Schmitt, PT, DPT, ATC PRO Sports Physical Therapy of Westchester Scarsdale, New York - USA Patrick Sells, DA, ES Belmont University Nashville, Tennessee – USA Laurie Stickler, MSPT, OCS Grand Valley State University Grand Rapids, Michigan – USA Steven R. Tippett, PT, PhD, SCS, ATC Bradley University Peoria, Illinois – USA Timothy F. Tyler, PT, ATC NISMAT Lenox Hill Hospital New York, New York – USA

Erik Witvrouw, PT, PhD Ghent University Ghent – Belgium

international JOURNAL OF

IJSPT

SPORTS PHYSICAL THERAPY

I N T E R N AT I O N A L J O U R N A L OF SPORTS PHYSICAL THERAPY

SPORTS PHYSICAL THERAPY SECTION

Editorial Staff

Executive Committee

Michael L. Voight, PT, DHSc, OCS, SCS, ATC Editor-in-Chief

Walter L. Jenkins, PT, DHS, LATC, ATC President

Barbara Hoogenboom, PT, EdD, SCS, ATC Grand Valley State University Grand Rapids, Michigan - USA Senior Associate Editor

Blaise Williams, PT, PhD Vice President Mitchell Rauh, PT, PhD, MPH, FACSM Secretary

Robert Manske, PT, DPT, Med, SCS, ATC, CSCS Wichita State University Wichita, Kansas – USA Associate Editor, Thematic Issues

Bryan Heiderscheit, PT, PhD Treasurer Stacey J. Pagorek, PT, DPT, SCS, ATC Representative-At-Large

Associate Editors John Dewitt PT, DPT, SCS, ATC The Ohio State University Sports Medicine Columbus, Ohio - USA

Administration Mark S. De Carlo, PT, DPT, MHA, SCS, ATC Executive Director

Terry Grindstaff PhD, PT, ATC Creighton University Omaha, Nebraska - USA

Mary Wilkinson Director of Marketing/Webmaster Managing Editor, Publications

International Associate Editors Mario Bizzini, PT, MSc Schulthess Clinic Zürich – Switzerland

Contact Information P.O. Box 431 Zionsville, Indiana 46077 877.732.5009 Toll Free 317.669.8276 Fax www.spts.org

Henning Langberg, PT, PhD, MSc Institute of Sports Medicine Copenhagen – Denmark Ashley Campbell Manuscript Coordinator Mary Wilkinson Managing Editor

Advertising Sales The International Journal of Sports Physical Therapy accepts advertising. Email Mary Wilkinson, Marketing Director, at mwilkinson@spts.org or contact by phone at 317.501.0805.

IJSPT is a bimonthly publication, with release dates in February, April, June, August, October and December.

I N T E R N AT I O N A L J O U R N A L OF SPORTS PHYSICAL THERAPY is a publication of the Sports Physical Therapy Section of the American Physical Therapy Association. IJSPT is also an official journal of the International Federation of Sports Physical Therapy (IFSPT).

ISSN 2159-2896

T

IFSPT

TABLE OF CONTENTS VOLUME 11, NUMBER 7

Page Number Article Title SYSTEMATIC REVIEW A Systematic Review and Meta-analysis Comparing Cardiopulmonary Exercise Test Values Obtained 1006 From the Arm Cycle and the Leg Cycle Respectively in Healthy Adults Authors: Larsen RT, Christensen J, Tang LH, Keller C, Doherty P, Zwisler AD. Taylor RS, Langberg H ORIGINAL RESEARCH 1040 The Effects of Instrument Assisted Soft Tissue Mobilization on Lower Extremity Muscle Performance: A Randomized Controlled Trial Authors: MacDonald N, Baker R, Cheatham SW 1048

Immediate Effects of Deep Trunk Muscle Training on Swimming Start Performance Authors:Iizuka S, Imai A, Koizumi K, Kaneoka K

1054

Changes in Dynamic Balance and Hip Strength After an Eight-week Conditioning Program in NCAA Division I Female Soccer (football) Athletes Authors: Ness BM, Constock BA, Schweinle WE

1065

Improvements in Knee Extension Strength are Associated with Improvements in Self-reported Hip Function Following Arthroscopy for Femoroacetabular Impingement Syndrome Authors: Davis CC, Ellis TJ, Amesur AK, Hewett TE, DiStasi S

1076

Effect of Different Foam Rolling Volumes on Knee Extension Fatigue Authors: Monteiro ER, Neto VGC

1082

Measuring Sport-Specific Physical Abilities in Male Gymnasts: The Men’s Gymnastics Functional Measurement Tool Authors: Sleeper MD, Kenyon LK, Elliott JM, Cheng S

1101

The Reliability of FABER Test Hip Range of Motion Measurements Authors: Bagwell JJ, Bauer L, Gradoz M, Grindstaff TL.

CASE REPORT/SERIES 1106 Modifying Marching Technique in Military Service Members With Chronic Exertional Compartment Syndrome: A Case Series Authors: Helmhout PH, Diebal-Lee A, Poelsma LR, Harts CC, Zimmermann WO 1125

Acute Tearing of the Oblique Abdominal Wall Insertion Onto the Iliac Crest in an Australian Football Player: A Case Report Authors: Murphy M, Stockden M, Breidahl B

1135

An Intervention-Based Clinical Reasoning Framework to Guide the Management of Thoracic Pain in a Dancer: A Case Report Authors: Masaracchio M, Kirker K, Collins CK, Hanney W, Liu X

1150

From Acute Achilles tendon Rupture to Return to Play – A Case Report Evaluating Recovery of Tendon Structure, Mechanical Properties, Clinical and Functional Outcomes Authors: Zeller JA, Cortes DH, Silbernagel KG

1160

A Non-Operative Approach to the Management of Chronic Exertional Compartment Syndrome in a Triathlete: A Case Report Authors: Gilden B, Collins CK

CLINICAL COMMENTARY / LITERATURE REVIEWS: 1177 Post-Operative Rehabilitation of Grade III Medial Collateral Ligament Injuries: Evidence-Based Rehabilitation and Return to Play Authors: Logan CA, O’Brien L, LaPrade RF 1191

Clinical Commentary on Midfoot and Forefoot Involvement in Lateral Ankle Sprains and Chronic Ankle Instability. Part 2: Clinical Considerations Authors: Frazer JJ, Feger MA, Hertel J

IJSPT

SYSTEMATIC REVIEW

A SYSTEMATIC REVIEW AND META-ANALYSIS COMPARING CARDIOPULMONARY EXERCISE TEST VALUES OBTAINED FROM THE ARM CYCLE AND THE LEG CYCLE RESPECTIVELY IN HEALTHY ADULTS Rasmus Tolstrup Larsen1,3,8 Jan Christensen1,2 Lars Hermann Tang1,3,4 Camilla Keller2,3 Patrick Doherty5 Ann-Dorthe Zwisler8 Rod S Taylor6,7 Henning Langberg1

ABSTRACT Introduction: The cardiopulmonary exercise test (CPET) assesses maximal oxygen uptake (VO2max) and is commonly performed on a leg cycle ergometer (LC). However, some individuals would rather perform the CPET on an arm cycle ergometer (AC).

Objective: The objectives of this study were to undertake a systematic review and meta-analysis of the difference in VO2max achieved by AC compared to LC in healthy adults and to explore factors that may be predictive of this difference.

Methods: MEDLINE, EMBASE, CINAHL, and PEDro were searched in April 2015. The differences in VO2max (ACLCdiff) were pooled across studies using random effects meta-analysis and three different methods were used to estimate the ratio between the values obtained from the tests (ACLCratio).

Results: This paper included 41 studies with a total of 581 participants. The mean ACLCdiff across studies was 12.5 ml/kg/ min and 0.89 l/min with a mean ACLCratio of 0.70. The ACLCdiff was lower in studies with higher mean age and lower aerobic capacity.

Conclusion: There is linear association between the AC and LC values in healthy adults. The AC values were on average 70% of the LC values. The magnitude of this difference appeared to be reduced in studies on older and less active populations.

Key words: Aerobic capacity, exercise testing, oxygen uptake, leg cycle, arm cycle, ergometer, systematic review, meta-analysis.

Level of evidence: 3a

1

CopenRehab, Section of Social Medicine, Department of Public Health, University of Copenhagen, Denmark 2 Department of Occupational- and Physiotherapy Therapy, Copenhagen University Hospital, Copenhagen, Denmark 3 Bachelor’s Degree Programme in Physiotherapy, Dept. of Rehabilitation and Nutrition, Faculty of Health and Technology, Metropolitan University College, Copenhagen, Denmark 4 Department of Cardiology, The Heart Centre, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark 5 Department of Health Sciences, University of York, England 6 Institute of Health Research, University of Exeter Medical School, Exeter, England 7 National Institute of Public Health, University of Southern Denmark, Copenhagen, Denmark 8 Danish Knowledge Centre for Rehabilitation and Palliative Care, University of Southern Denmark

CORRESPONDING AUTHOR Rasmus Tolstrup Larsen Henrik Pontoppidans Vej 6, 1st floor.

DK-2200 Copenhagen N, Denmark E-mail: tolstruplarsen@gmail.com Phone: +4542423007

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INTRODUCTION The cardiopulmonary exercise test (CPET) is the gold standard for the direct assessment of maximal oxygen uptake (VO2max).1-5 VO2max determines the maximal ability for the human body to deliver, obtain and consume oxygen during maximal exercise and is a measure of maximum aerobic capacity.4 Assessments of aerobic capacity are used by healthcare professionals to evaluate exercise capacity,5 exercise intolerance 6 and functional aerobic impairment,7 which all provide important information on health status and prognosis in various populations.2,8-11 CPET is commonly performed on a treadmill or on a leg cycle ergometer (LC).3,5 However, due to disability, co-morbidity, preference or athletic discipline there is a need to investigate alternatives to the LC test.12 In some cases, it could be more important to assess aerobic fitness using the arms when leg exercise is not feasible or possible.13-15 A potential alternative is to perform the test with the upper body using an arm cycle ergometer (AC).13 However, the AC has limitations as studies have shown that untrained individuals will achieve a lower level of VO2max on the AC, due to a reduced stress on the cardiovascular system, compared to the LC test.12,15,16 Having a smaller amount of muscle mass being active during the test, AC is likely to result in an earlier termination of the CPET due to peripheral factors such as an earlier onset of lactate threshold, rather than central cardiovascular limitations.12,17 While individual studies have directly assessed the difference in VO2max of a CPET conducted using AC compared to LC in healthy adults, no previous systematic review of these studies has been published.

The objectives of this study were to undertake a systematic review and meta-analysis of the difference in VO2max achieved by AC compared to LC in healthy adults and to explore factors that may be predictive of this difference. The determination of this factor would allow the direct comparison of data obtained on the two tests.

METHODS This review was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.18

DATA SOURCES AND SEARCHES Preliminary searches were conducted and relevant search terms identified. A formal search of the databases MEDLINE, EMBASE, CINAHL, and PEDro was undertaken in April 2015. References of the identified studies in the preliminary searches were screened and relevant search terms were added to the search strategy. The search strategy consisted of a combination of relevant keywords and MeSH/Thesaurus terms for: 1) direct assessment of VO2max (or VO2peak), 2) a CPET performed on an AC and 3) a CPET performed on an LC. No language or publication limits were applied. The reference lists of identified studies were checked and the authors of unobtainable studies were contacted. Papers suggested by experts in the field were evaluated. Search strategies specified for MEDLINE are presented in Appendix 1.

STUDY SELECTION Study selection was undertaken based on a priori defined criteria. Only original research papers reporting within comparison (AC and LC) VO2max (or VO2peak), as milliliter oxygen per kilogram per minute (ml/min/kg) or as liters per minute (l/min), were considered eligible for inclusion in this systematic review. The CPET had to be non-assisted on AC and LC. Studies that reported values for healthy adults (age >18 years) with a level of physical activity < 300 minutes per week were included. People with higher physical activity levels were considered athletes and where therefore excluded.19 Two authors (RTL, CK) independently screened titles and abstracts and assessed eligible articles in full-text. Any inconsistencies between authors were discussed and disagreement was solved by consultation with a third author (JC).

DATA EXTRACTION AND RISK OF BIAS ASSESSMENT The following information was extracted: sample size, gender distribution, mean age, mean height, body mass index (BMI) together with the VO2max values, peak respiratory exchange ratio (RER), CPET starting watt, and watt increment for both the AC and LC test.

The Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies (QAT)20 was used to assess

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the methodological quality of all included studies.

Six items (6-10 and 13) were considered not applicable for the studies included in this review and thus did not contribute to the quality rating total score (SumQAT). Two authors (RTL and CK) independently extracted data and undertook the quality assessment. Inconsistencies between reviewers were discussed and in cases of disagreement, a third reviewer (JC) was consulted.

DATA ANALYSIS The mean VO2max difference between the AC test and the LC test (ACLCdiff) was calculated for each study. Given the within subject nature of these comparisons the standard deviation (SD) of this difference for the within subject correlation was adjusted, using the method described in chapter 16.4.6.1 of the Cochrane Handbook.21 Hereby the SD was calculated using an imputed r-value of 0.5. The level of statistical heterogeneity was assessed using the I2 score. Given the variation of participant characteristics across included studies the ACLCdiff, for ml/ kg/min and l/min, were pooled across studies using a random effects meta-analysis. Summary of the characteristics of included studies are expressed as median values and interquartile range (IQR).

Meta-regressions were used to perform sub-group analyses to clarify which variables were affecting the main analysis on the ACLCdiff. The sub-groups included were: aerobic capacity (as a categorical variable based on the Åstrand classification -“low”, “fair”, “average”, “good” or “high”),22 participant mean age (in years), gender (percentage of males), study risk of bias (SumQAT), and the difference in obtained peak RER values during test.

Three different approaches were used to find the ratio between AC and LC (ACLCratio). First a metaanalysis of the ACLCratio was undertaken using the studies presenting the group mean ± SD of the within comparison ratio (%). Second, a linear regression model was determined using the group mean values. The linear regression analysis was weighted by sample size. Third the reported AC values were divided with the reported LC values, giving an estimate of the ratio in each study, which are expressed as a total mean ratio.

All analyses were performed using Review Manager 5.3 (Cochrane collaboration) software and Stata 14.0 software (StataCorp. 2013. Stata Statistical Software: Release 14.9 College Station, TX: StataCorp LP). A p-value ≤ 0.05 was considered statistically significant.

RESULTS Results of the search The electronic searches identified 3,300 records.

After removal of 617 duplicates, 2,683 unique studies remained. 2,510 studies were excluded by screening their title and abstract and 171 studies were considered eligible for full text review. Of these, 130 did not meet the inclusion criteria. Thus, 41 studies (published between 1973 and 2014) were included in the review.12,15,17,23-60 The study selection process is summarized as a flow chart in Figure 1.

Description of studies A summary of the characteristics of the 41 included studies is provided in Table 1. Some of the included studies reported results from several groups and the data extraction and risk of bias were therefore performed on 53 groups. The full details of included studies are listed in Appendix 2.

Risk of bias in included studies Figure 2 presents a summary of the risk of bias in the included groups. The median SumQAT was 4 points, (IQR: 3 to 5). A detailed risk of bias figure is presented in Appendix 3.

Research question and study population Although all included groups were judged to have a well-defined research question (Item 1), 1315,17,25,30,3438,44,47,52,53 had insufficient description of the population (Item 2). One group 43 described the participation rate of eligible subjects (Item 3) and 13 15,24,26,29,32,33,35, 36,41,43,46,55,57 had a well-defined description of the subject selection (Item 4). Four groups 15,38,39,46 included sample size justification (item 5).

Outcome measures Five groups 17,34,40,45,53 did not report the VO2max as ml/ kg/min but as l/min (item 11) and therefore did not adjust the outcome for subject weight.

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Table 1. Study Characteristics of the 53 included groups

Figure 1. Flowchart illustrating the systematic literature search, screening of studies and full text assessment.

Blinding and statistical analysis One group12 blinded the outcome assessor (Item 12) and 1225,34,37,38,40,42,43,45,48,51,52,55 did not provide report a description of their statistical analysis methods (Item 14).

META-ANALYSIS OF VO2MAX DIFFERENCE BETWEEN AC AND LC A total of 36 groups (413 participants) reported data for the ACLCdiff measured in ml/kg/min. The metaanalysis for the ACLCdiff is shown in Figure 3 with a pooled mean ACLCdiff of 12.5 ml/kg/min, (95% CI: 10.3 to 14.7, I2 = 59.9%, p > 0.001) favouring the LC test values. A total of 37 groups (415 participants) presented data of the ACLCdiff in l/min with a pooled

mean ACLCdiff of 0.89 l/min, (95% CI: 0.78 to 1.00, I2 = 30.5%, p=0.043) favouring the LC values as shown in Figure 4.

SUBGROUP ANALYSES In univariate meta-regression and multivariate metaregression lower participant mean age and higher aerobic capacity were found to be significantly asso-

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ciated to an increased ACLCdiff. The meta-regressions are shown in Table 2.

Figure 2. Risk of bias graph. Review authorsâ&#x20AC;&#x2122; judgements about each risk of bias item presented as percentages across all included studies.

ANALYSES OF THE AC/LC RATIO The mean ratio between the AC test and the LC test for the 37 groups (n=413 participants) reporting VO2max in ml/kg/min was 0.70 (95% CI: 0.66 to 0.73) in favour of the LC. The corresponding value of the 37 groups (n=415 participants) reporting VO2max in l/min, the mean ACLCratio was 0.71 (95% CI: 0.66 to 0.75). The meta-analysis (n=46 participants) for the ACLCratio across groups was 71%, (95% CI: 68 to 74, I2 = 0%, p=0.530) (figure 5). The coefficient for the linear regression in Figure 6, between the AC and

Figure 3. Random effects meta-analysis of the difference between group means for arm cycle (AC) and leg cycle (LC) in ml/kg/min.

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Figure 4. Random effects meta-analysis of the difference between group means for arm cycle (AC) and leg cycle (LC) in l/min.

the LC mean VO2max was 0.65 ml/kg/min (95% CI: 0.48 to 0.81) with an r2 of 0.689.

DISCUSSION This systematic review and meta-analysis brings together data from 41 studies and 53 groups in 581 healthy individuals directly comparing VO2max values obtained from the AC compared to LC. The LC values were found to be substantively higher (mean difference: 12.5 ml/kg/min and 0.89 l/min) than the AC

values. But with an I2 value of 59.9% for the ACLCdiff in ml/kg/min these results could be affected by substantial heterogeneity. The results support the belief that the AC test achieves lower oxygen uptake values as it involves a smaller amount of muscle mass and places less stress on the cardiovascular system.12,15,16 Both age and the aerobic capacity appear to be associated with the ACLCdiff. The difference is decreased with increasing age and increased with better aero-

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Table 2. Meta-regression analyses performed on each variable (univariate) and adjusted for all variables (multivariate)

Figure 5. Random effects meta-analysis comparing studies that reports ratio values for the within person comparison between arm cycle (AC) and leg cycle (LC) as group mean Âą SD.

bic capacity. This was expected, due to the fact that aerobic capacity decreases with age.22 The RER represents the relationship between the volume of carbon dioxide and the volume of oxygen

in every breath and it is recommended to continue VO2max tests until RER values above 1.1 are reached in order to obtain a valid CPET.23 The majority of groups reporting RER values reported values in both tests to be above 1.1.23,24,26-29,32,36,38,46,60 Only one group

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no important heterogeneity was found.62 Three different methods were used to estimate the ACLCra. The calculation and the linear regression of the tio ACLCratio should only be used as a prediction, since they do not incorporate variation. Despite different approaches to estimate the ratio, the results are very similar and the ACLCratio of 0.7 is similar to the ones described in the literature.33,39,46,54 To investigate if the 0.7 is a valid estimate for the population mean ACLCratio, future research should report within comparison ratios between the AC and the LC, making them applicable for inclusion in meta-analysis.

Figure 6. Two-way scatter plot and best ďŹ tted line between the mean arm cycle (AC) maximal oxygen uptake (VO2max) values and mean VO2max leg cycle (LC) values.

reported RER values above 1.1 for the AC and below 1.1 for the LC,23 and three groups reported RER for both test to be below 1.1.33,39,49 The difference in the obtained RER values were expected to affect the ACLCdiff. However, this relationship was not found, which could be due to a lack of power, as not all included groups reported the values for the metaregressions. The level of aerobic capacity is affected by gender.22 However, a correlation between gender distribution and the ACLCdiff was not found. This makes our results applicable for future research and clinical use in single gender groups as well as mixed gender groups.

The ACLCdiff does not seem to be affected by the risk of bias in the studies as low quality studies are reporting the same ACLCdiff as high quality studies.

This may be explained by the precise and accurate equipment used during CPET,61 and thereby limits the possibility of imprecise testing in different settings, which increases the clinical applicability.

The most accurate estimate of the ratio is the metaanalysis of the reported ratios, but only four groups 33,39,46,54 reported mean Âą SD (%) values for the ratio between the tests. The meta-analysis revealed a linear relationship between the AC test values and the LC test values with an ACLCratio of 0.7. This analysis should be seen as the main expression for the ratio between the values of the AC and the LC, where

This is the first systematic review and meta-analysis of the literature comparing arm and leg exercise, and it is thus important to stress that this paper has a number of limitations. First, some groups did not report ACLCdiff SD. Thus, imputation was performed of the value based on an assumed within participant correlation coefficient (r-value) between AC and LC VO2max. This method is recommended by the Cochrane Handbook 21 but may still influence the accuracy of the findings. The only way to avoid these limitations in a meta-analysis is for future research to report the correlation coefficients between the two tests. However, sensitivity analyses were undertaken to assess the impact of this estimation on the findings. A small number of groups have reported a range of correlation coefficients between the AC test and the LC test (0.78, 0.94, 0.77, 0.32, 0.70).12,17,31,37,54 A sensitivity analysis was performed on the r-values and the pooled ACLCdiff was found to be 12.52 ml/kg/min (95% CI: 10.2 to 14.6) based on the lowest of the reported r-values (0.32) and 12.6 ml/kg/min (95% CI: 10.6 to 14.7) based on the highest reported r-value (0.94). Thus, it was shown that this imputation method made no difference to the pooled results. Future studies should report the standard deviation (or equivalent) of the mean difference between AC ad LC VO2max or the within person correlation coefficient.

Second, the quality of the included studies was variable. This review sought to assess study risk of bias using the QAT as it can be applied to cross-sectional studies.20 However, to make this tool relevant for this review some of the original QAT elements (items 6-10 and item 13) were dropped, as they were inapplicable to the research question. This could affect

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the reliability of the tool, and hereby the method of assessing the risk of bias, but the remaining items should be a good measure specific to the method of this paper.

Third, this review was limited to non-athlete healthy adults and limits generalizability of the current findings. Non-athlete healthy adults are expected to have a larger aerobic capacity when doing CPET using the legs compared to the arms due to everyday use and large lower limb muscle mass.29 However, in athletic populations, particularly arm-trained populations, the ACLCdiff is expected to be smaller than shown in this review.63 To avoid systematic bias, 18 comparisons in individuals performing more than 300 minutes per week of physical activity or involved in competitive exercise were excluded.19 Those groups contained ‘well trained subjects’, ‘triathletes’, ‘swimmers’, ‘cross-country skiers’ or ‘highly arm-trained’.

However, no exclusion sedentary individuals was made. Two of the groups included extremely sedentary or sedentary subjects.39,47 But having an ACLCraof 0.76 and 0.64 these groups are not likely to have tio had a systematic affect on the final results. A sensitivity analysis was performed without the two groups and showed no impact on the result as the pooled ACLCdiff was found to be 12.7 ml/kg/min (95% CI: 10.4 to 15.0). Future well-conducted studies that directly compare AC and LC in other populations are needed. Future research should also include disease populations with limitations by lower limb disability such as peripheral vascular disease or osteoarthritis, or trained and upper extremity dominant athletes.

CONCLUSION This systematic review and meta-analysis showed that the VO2max achieved by the AC tests were on average 70% of the VO2max achieved by the LC test, in studies on healthy non-athletic individuals. There was a linear association between the VO2max for the AC test and the LC test. The magnitude of this difference appeared to be reduced in studies with older and less active populations.

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35. Davis JA, Vodak P, Wilmore JH. Anaerobic threshold and maximal aerobic power for three modes of exercise. J Appl Physiol. 1976;41(4):544-550.

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37. Franklin BA, Vander L, Wrisley D, Rubenfire M. Aerobic requirements of arm ergometry: Implications for exercise testing and training. Phys Sportsmed. 1983;11(10):81-90.

38. Franssen FME, Wouters EFM, Baarends EM, Akkermans MA, Schols AMW. Arm mechanical efficiency and arm exercise capacity are relatively preserved in chronic obstructive pulmonary disease.

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39. Javierre C, Alegre J, Ventura JL, et al. Physiological responses to arm and leg exercise in women patients with chronic fatigue syndrome. J Chronic Fatigue Syndr. 2007;14(1):43-53.

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42. Louhevaara V, Sovijarvi A, Ilmarinen J, Teraslinna P. Differences in cardiorespiratory responses during and after arm crank and cycle exercise. Acta Physiol Scand. 1990;138(2):133-143.

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43. Lyons S, Richardson M, Bishop P, Smith J, Heath H, Giesen J. Excess post-exercise oxygen consumption in untrained men following exercise of equal energy expenditure: Comparisons of upper and lower body exercise. Diabetes Obes Metab. 2007;9(6):889-894.

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52. Sargeant AJ, Davies CTM. Perceived exertion during rhythmic exercise involving different muscle masses. J Hum Ergol. 1973;2(1):3-11.

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Turner DL, Hoppeler H, Claassen H, et al. Effects of endurance training on oxidative capacity and structural composition of human arm and leg muscles. Acta Physiol Scand. 1997;161(4):459-464.

58. Warren GL, Cureton KJ, Dengel DR, Graham RE, Ray CA. Is the gender difference in peak V(O2) greater for arm than leg exercise? Europ J Appl Physiol.

1990;60(2):149-154.

59. Yasuda N, Gaskill SE, Ruby BC. No gender-specific differences in mechanical efficiency during arm or leg exercise relative to ventilatory threshold. Scand J Med ci Sports. 2008;18(2):205-212.

60. Yasuda N, Ruby BC, Gaskill SE. Substrate oxidation during incremental arm and leg exercise in men and women matched for ventilatory threshold. J Sports Sci. 2006;24(12):1281-1289.

61. Bhagwat M, Paramesh K. Cardio-pulmonary exercise testing: An objective approach to pre-operative assessment to define level of perioperative care.

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APPENDIX 1. Search strategy for MEDLINE Search item 1 Bicycling [MeSH] Ergometry [MeSH] Leg [MeSH] CPET leg CPETleg Cycle ergometry Leg cycle ergometry cycle ergometer bicycle ergometer Electromagnetically braked ergometer Lower body exercise Cardiopulmonary exercise testing leg Cardiopulmonary exercise testing ETT Exercise tolerance test Leg exercise Cycling Cycle exercise Leg cycling Leg ergometry

Search item 2 Arm [MeSH] CPET arm Arm cycle ergometry Arm-crank ergometry Arm ergometry CPETarm Arm crank Arm crank ergometer Arm ergometer Arm cycle ergometer

Search item 3 Oxygen consumption [MeSH] Physical endurance [MeSH] Exercise test [MeSH] Fatigue [MeSH] Physical exertion [MeSH] Oxygen uptake Physical fitness VO2 VO2 max VO2max

Arm cycling Upper body exercise

Oxygen consumption Peak oxygen consumption

Arm cranking Cardiopulmonary exercise testing arm Arm exercise Cranking Arm work

Anaerobic threshold VO2 peak VO2peak Maximal aerobic power Aerobic power Aerobic capacity Work capacity Peak pulmonary O2 metabolic efficiency Maximal oxygen uptake Oxygen uptake Peak exercise Peak physiologic responses Cardiorespiratory responses Physiological comparison

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APPENDIX 2. Detailed characteristics of included studies

Aminoff, T. et al. (1996) Title Physical work capacity in dynamic exercise with differing muscle masses in healthy young and older men Methods Cross-sectional Participant 19 healthy, non-smokers, and physically active men. Subjects participated in status conditioning exercises, on average, two to four times a week.

56.9 Gender (M/F): Only males 78

2.3 years 4.8 cm 11.1 kg 2.3 kg/m2 0.08 0.05

3.1 kg/m2

Study protocol AC or LC tested first: Random Time between tests: 1 day AC Start Watt: not reported LC Start Watt: not reported AC Watt increase/min: 5.35 W/min LC Watt increase: 10.7 W/min Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 4

Aminoff, T. et al. (1999) Title Physiological strain during kitchen work in relation to maximal and task-specific peak values Methods Cross-sectional Participant Nine kitchen workers from a large hospital kitchen with a conveyor belt, collecting and status sorting dirty plates.

32.3 female female female 1.7 kg/m2 female male female male

male

8.6 years

male 5.4 cm male 75.1 5.9 kg male 3.1 kg/m2

Study protocol

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APPENDIX 2. Detailed characteristics of included studies (continued)

AC or LC tested first: LC Time between tests: 1 day AC Start Watt: not reported LC Start Watt: not reported AC Watt increase/min: 5.5 W/min

Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 5

Bhambhani, Y, et al, (1998) Title Muscle oxygenation during incremental arm and leg exercise in men and women Methods Cross-sectional Participant Fifteen men and 10 women who were free from metabolic and cardiorespiratory diseases. status The volunteers were university students and members of local sports club.

27.3

male

5.3years

female male 8.0 cm female male 8.5 kg female 3.9 kg/m2 male 2.1 kg/m2 female male female male Study protocol AC or LC tested first: Random Time between tests: Within one week AC Start Watt: 25 LC Start Watt: 30 AC Watt increase/min: 12.5 W/min LC Watt increase: 15 W/min Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 5

Bhambhani, Y, et al, (1995) Title Prediction of stroke volume during upper and lower body exercise in men and women Methods Cross-sectional Participant 37 recreationally active subjects not involved in any particular exercise-training status programme.

32.1

male

7.3 years

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APPENDIX 2. Detailed characteristics of included studies (continued)

female female female female female

male male 2

6.6 cm 9.1 kg 2

male male male

Study protocol AC or LC tested first: Random Time between tests: Within two weeks AC Start Watt: 12.5 LC Start Watt: 30 AC Watt increase/min: 6.25 W/min LC Watt increase: 15 W/min Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 5

Bhambhani, Y, et al, (1991) Title Transfer effects of endurance training with the arms and legs Methods RCT Participant 16 healthy middle-aged male subjects in the arm group, and 8 healthy middle-aged male status subjects in the leg group.

35.2

leg

Height: arm

4.7 years

leg arm

leg 2

arm arm arm

5.0 cm 11.1 kg 2

leg leg leg

Study protocol AC or LC tested first: Random Time between tests: Within two weeks AC Start Watt: 12.5 LC Start Watt: 30 AC Watt increase/min: 6.25 W/min LC Watt increase: 15 W/min Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 4

Barstow, T. J. et al. (1993)

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APPENDIX 2. Detailed characteristics of included studies (continued)

Title Methods Participant status

O2 uptake kinetics and the O2 deficit as related to exercise intensity and blood lactate Cross-sectional Four untrained subjects aged 24-38 years, weight 59-89 kg n=4 Age: 24-38 years Gender (M/F): Three males and one female arm leg 5.0 cm Bodyweight: 59-89 kg

Study protocol AC or LC tested first: Cannot determine (CD) Time between tests: not reported AC Start Watt: Not reported LC Start Watt: Not reported AC Watt increase/min: Not reported LC Watt increase: Not reported Outcomes of interest Risk of bias Notes

VO2max SumQAT: 3

Boileau, R. A. et al. (1984) Title Cardiovascular and metaboli contributions to the maximal power of the arms and legs Methods Cross-sectional Participant Moderately active, nonathletic male college students. status n=40 Age: 18-25 years Gender (M/F): only males Bodyweight: 75.8 kg AC RER: 1.16 LC RER: 1.16 Study protocol AC or LC tested first: Random Time between tests: Cannot determine AC Start Watt: 60 LC Start Watt: 150 AC Watt increase/min: 6 LC Watt increase: 15 Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 6

Bond, V. et al. (1986) Titel Aerobic capacity during two-arm and one-leg exercise

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APPENDIX 2. Detailed characteristics of included studies (continued)

Methods Participant status

Cross-sectional Eight healthy males. The subjects had not participated in any upper or lower body conditioning for 12 months prior to the tests n=8 Age: 24 4.7 years Gender (M/F): only males Height: 177 6.5 cm Bodyweight: 77 9.8 kg BMI: 24.58 kg/m2

Study protocol AC or LC tested first: Random Time between tests: Within one weeks AC Start Watt: 30 LC Start Watt: 30 AC Watt increase/min: 30 W/min LC Watt increase: 30 W/min Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 4

Bouchard, C. et al. (1979) Title Specificity of maximal aerobic power Methods Cross-sectional Participant 30 moderately active male subjects. status n = 30 Age: 28 years Gender (M/F): only males Bodyweight: 73.0 6.6 Study protocol AC or LC tested first: Random Time between tests: Within two weeks AC Start Watt: 75 LC Start Watt: 125 AC Watt increase/min: 10 W/min LC Watt increase: 25 W/min Outcomes of interest Risk of bias Notes

VO2max SumQAT: 5 The study reports a correlation coefficient between AC and LC on r = 0.70.

Castro, R. et al. (2011) Title Different ventilatory responses to progressive maximal exercise test performed with either the arms or legs Methods Cross-sectional

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APPENDIX 2. Detailed characteristics of included studies (continued)

Participant status

12 subjects of hospital staff and university students. They were considered healthy upon a clinical evaluation (physical examination and clinical history) and a maximal exercise test performed on a cycle ergometer. None of the subjects were engaged in regular physical exercise. None of the subjects were accustomed to arm-crank exercise.

Group n=12 Age: 27 years Gender (M/F): Six males and six females BMI: 22.7 0.7 kg/m2 AC RER: 1.37 0.03 LC RER: 1.26 0.03

Study protocol AC or LC tested first: Not reported Time between tests: Not reported AC Start Watt: 30 LC Start Watt: 30 AC Watt increase/min: 20 W/min LC Watt increase: 15 W/min Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 6

Charbonnier, J. P. et al. (1975) Title Experimental study on the performance of competition swimmers.

Methods Cross-sectional Participant Six non-swimmers with a mean age of 31 4 years, a mean height of 178 3 cm and a status mean bodyweight of 71 5 kg. The swimmers were among the best in the country and the non-swimmers were members of the laboratory staff.

Group n=6 Age: 31 4 years Gender (M/F): Three males and three females Height: 178 3 cm Bodyweight: 71 5 kg BMI: 22.41 kg/m2 AC RER: 1.06 0.01 LC RER: 1.04 0.03 Study protocol AC or LC tested first: Not reported Time between tests: Not reported AC Start Watt: Not reported LC Start Watt: Not reported AC Watt increase/min: Not reported LC Watt increase: Not reported Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 5

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APPENDIX 2. Detailed characteristics of included studies (continued)

Davies, C. T. M., & Sargeant, A. J. (1974) Title Indirect determination of maximal aerobic power output during work with one or two limbs.

Methods Cross-sectional Participant 12 healthy male subjects. All except four subjects were accustomed to physical status investigations.

Group n=12 Age: 30.5 6.2years Gender (M/F): only males Height: 178.2 5.1 cm Bodyweight: 75.1 10.1 kg BMI: 23.65 kg/m2 Study protocol AC or LC tested first: Not reported Time between tests: Not reported AC Start Watt: Not reported LC Start Watt: Not reported AC Watt increase/min: Not reported LC Watt increase: Not reported Outcomes of interest Risk of bias Notes

VO2max SumQAT: 1

Davis, J. A. et al (1976) Title Anaerobic threshold and maximal aerobic power for three modes of exercise.

Methods Cross-sectional Participant 39 healthy university male students. None of them had been endurance training four status months prior to the experiment. Nine of the 39 subjects participated only in the validation period.

Group n=30 Age: 22.5 2.6 years Gender (M/F): only males Height: 179.8 6.9 cm Bodyweight: 75.5 9.0 kg BMI: 23.35 kg/m2 Study protocol AC or LC tested first: Not reported Time between tests: One day AC Start Watt: not reported LC Start Watt: not reported AC Watt increase/min: not reported LC Watt increase: not reported

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APPENDIX 2. Detailed characteristics of included studies (continued)

Outcomes of interest Risk of bias Notes

VO2max SumQAT: 4

Dekerle, J. et al. (2002) Title Ventilatory thresholds in arm and leg exercices with spontaneously chosen crank and pedal rates.

Methods Cross-sectional Participant 20 male students in physical education with a mean age of years, a mean height of cm status and a mean bodyweight of kg.

Group n=12 Age: 22 2.2 years Gender (M/F): only males Height: 180 6 cm Bodyweight: 73.5 5.3 kg BMI: 22.69 kg/m2 AC RER: 1.2 0.1 LC RER: 1.2 0.1 Study protocol AC or LC tested first: not reported Time between tests: Within one week AC Start Watt: 30 LC Start Watt: 60 AC Watt increase/min: 15 LC Watt increase: 30 Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 4

Franklin, B. A. et al. (1983) Titel Aerobic requirements of arm ergometry: implications for exercise testing and training Methods Cross-sectional Participant 10 healthy male subjects. status Group n=10 Age: 28 2.4 years Gender (M/F): only males Height: 170.7 7.5 cm Bodyweight: 69.3 7.1 kg BMI: 23.78 kg/m2 AC RER: 1.06 0.09 LC RER: 1.12 0.11 Study protocol AC or LC tested first: not reported Time between tests: One day

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APPENDIX 2. Detailed characteristics of included studies (continued)

AC Start Watt: not reported LC Start Watt: not reported AC Watt increase/min: not reported LC Watt increase: not reported Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 2 The study reports a correlation coefficient between AC and LC on r = 0.32.

Franssen, F. M. et al. (2002) Title Arm mechanical efficiency and arm exercise capacity are relatively preserved in chronic obstructive pulmonary diseas Methods Cross-sectional Participant Controls, male/female (14/6) did not participate in any exercise-training program and status were found through an advertisement in the local newspaper Group n= 20 Age: 61 1 years Gender (M/F): 14 males and six females BMI: 25.9 0.6 kg/m2 AC RER: 1.22 0.02 LC RER: 1.23 0.02 Study protocol AC or LC tested first: not reported Time between tests: One week AC Start Watt: not reported LC Start Watt: not reported AC Watt increase/min: not reported LC Watt increase: not reported Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 4

Javierre, C. et al. (2007) Title Physiological responses to arm and leg exercise in women with chronic fatigue syndrome.

Methods Cross-sectional Participant 15 healthy controls that were extremely sedentary. Their occupation did not require status physical effort, they did not perform physical activity and or their hobbies were sedentary.

Group n= 15 Age: 61 1 years Gender (M/F): only females Bodyweight: 57.5 5.1 kg Height: 159 5 cm BMI: 22.74 kg/m2

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APPENDIX 2. Detailed characteristics of included studies (continued)

AC RER: 1.05 0.11 LC RER: 1.08 0.09 Study protocol AC or LC tested first: AC Time between tests: 10 minutes AC Start Watt: 10 LC Start Watt: 0 AC Watt increase/min: 10 W/min LC Watt increase: 12.5 W/min Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 6

Keteyian, S. et al. (1994) Title Cardiovascular responses of cardiac transplant patients to arm and leg exercise.

Methods Cross-sectional Participant 10 healthy normal men. Five healthy subjects performed leg exercise three or more times status per week and one healthy adult performed arm and leg exercise three times per week.

Group n= 15 Age: 51 5 years Gender (M/F): only males Bodyweight: 80.4 15.6 kg Study protocol AC or LC tested first: Random Time between tests: One hour AC Start Watt: 15 LC Start Watt: 30 AC Watt increase/min: 15 W/min LC Watt increase: 10 W/min Outcomes of interest Risk of bias Notes

VO2max SumQAT: 3

Lewis, S. et al. (1980) Title Transfer effects of endurance training to exercise with untrained limbs Methods RCT Participant Five healthy male college students. status Group n=5 Age: 22 2 years Gender (M/F): only females Bodyweight: 79 13 kg Height: 186 10 cm BMI: 22.84 kg/m2

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APPENDIX 2. Detailed characteristics of included studies (continued)

AC RER: 1.27 0.06 LC RER: 1.28 0.07 Study protocol AC or LC tested first: Random Time between tests: Within one week AC Start Watt: 25 LC Start Watt: 50 AC Watt increase/min: 7 W/min LC Watt increase: 33 W/min Outcomes of interest Risk of bias Notes

VO2max SumQAT: 6

Loughney, L. et al. (2014) Title Comparison of oxygen uptake during arm or leg cardiopulmonary exercise testing in vascular surgery patients and control subjects Methods Cross-sectional Participant Twenty healthy control subjects . status Group n=20 Age: 31 (24 42) years Gender (M/F): 10 males and 10 females BMI: 26 (24 28) kg/m2 Study protocol AC or LC tested first: not reported Time between tests: not reported AC Start Watt: not reported LC Start Watt: not reported AC Watt increase/min: not reported LC Watt increase: not reported Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 5 The study reports a correlation coefficient between AC and LC on r = 0.77.

Louhevaara, V. et al. (1990) Title Differences in cardiorespiratory responses during and after arm crank and cycle exercise.

Methods Cross-sectional Participant 21 untrained healthy men. status Group n= 21 Age: 33.3 5.9 years Gender (M/F): only males Bodyweight: 78.3 12.7 kg

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APPENDIX 2. Detailed characteristics of included studies (continued)

Participant status

Healthy subjects.

Group n= 10 Age: 29.4 years Gender (M/F): Five males and five females Bodyweight: 63.5 AC RER: 1.09 0.08 LC RER: 1.17 0.01

Study protocol AC or LC tested first: Random Time between tests: Within one week AC Start Watt: not reported LC Start Watt: not reported AC Watt increase/min: not reported LC Watt increase: not reported Outcomes of interest Risk of bias Notes Nag, P. K. (1984) Title Methods Participant status

VO2max and RER SumQAT: 3

Circulo-respiratory responses to different muscular exercises Cross-sectional Five young men, free from any cardiovascular. They actively participated habitually in moderately heavi agricultural work, none were the limb and trunk muscles specially trained.

Group n= 5 Age: 22.7 3.4 years Gender (M/F): only males Bodyweight: 48.9 0.9 kg Height: 160.2 2.0 cm BMI: 19.05 kg/m2 AC RER: 1.2 LC RER: 1.01

Study protocol AC or LC tested first: Random Time between tests: not reported AC Start Watt: 50-75 LC Start Watt: 50-75 AC Watt increase/min: 25-50 LC Watt increase: 25-50 Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 3

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APPENDIX 2. Detailed characteristics of included studies (continued)

Orr, J. L. et al. (2013) Title Cardiopulmonary exercise testing: arm crank vs cycle ergometry Methods Cross-sectional Participant Fifteen healthy women were recruited from the University of Dundee. status Group n= 15 Age: 23.5 3.7 years Gender (M/F): Only females Bodyweight: 60.6 7.8 kg Height: 167 5 cm BMI: 21.73 kg/m2 Study protocol AC or LC tested first: Random Time between tests: 30 minutes AC Start Watt: 15 LC Start Watt: 25 AC Watt increase/min: 25-50 LC Watt increase: 25 Outcomes of interest Risk of bias Notes

VO2max SumQAT: 5

Pogliaghi, S. et al. (2006) Title Adaptations to endurance training in the healthy elderly: arm cranking versus leg cycling Methods RCT study Participant 18 men were recruited by local advertisements in the metropolitan area of Verona status (Italy).

68 4 66 5 73 4 years Gender (M/F): only males Bodyweight: 74 6 76 11 80 8 kg Height: 172 4 169 6 173 8 cm BMI: 25 2 kg/m2 27 3 kg/m2 27 2 kg/m2 AC RER: 1.2 0.1 1.2 0.1 1.1 0.07 LC RER: 1.2 0.07 1.2 0.06 1.2 0.05 Study protocol AC or LC tested first: Random Time between tests: 60 minutes AC Start Watt: 40 LC Start Watt: 50 AC Watt increase/min: 5 LC Watt increase: 10 Outcomes of interest

VO2max and RER

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APPENDIX 2. Detailed characteristics of included studies (continued)

Risk of bias Notes

SumQAT: 7

Protas, E. J. et al. (1996) Title Cardiovascular and metabolic responses to upper- and lower-extremety exercise in men Methods Participant status

Cross-sectional study 7 control subjects from the local community with a mean age of 65 (53-71) were recruited. The controls were more sedentary than the PD group.

Group n=7 Age: 53-71 Gender (M/F): only males AC RER: 1.07 (1.0-1.18) LC RER: 1.12 (1.01-1.23)

Study protocol AC or LC tested first: Random Time between tests: 20 minutes AC Start Watt: 10 LC Start Watt: 20 AC Watt increase/min: 5 LC Watt increase: 10 Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 3

Rathnow, K. M., & Mangum, M. (1990) Title Cardiopulmonary exercise testing: arm crank vs. cycle ergometry Methods Cross-sectional Participant The single mode treatment group consisted of six males and three females. The mixed status mode treatment group consisted of five males and three females. Due to the presentation of data in the study, and mixture of sexes in the groups this study will appear with no demographic data.

AC RER: 1.09 0.08 LC RER: 1.15 0.08

1.

0.08 1.16 0.08

1.07 0.07 1.07 0.06

Study protocol AC or LC tested first: LC Time between tests: at least 20 minutes AC Start Watt: 15 LC Start Watt: 50-150 AC Watt increase/min: 25-50 LC Watt increase: 50

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APPENDIX 2. Detailed characteristics of included studies (continued)

Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 5

Reybrouck, T. et al. (1975) Title Limitations to maximum oxygen uptake in arm, leg and combined arm and leg ergometry.

Methods Cross-sectional Participant The untrained subject was 25 years old. status Group n=1 Age: 25 years Gender (M/F): only males AC RER: 0.95 0.03 LC RER: 1.16 0.05 Study protocol AC or LC tested first: not reported Time between tests: not reported AC Start Watt: not reported LC Start Watt: not reported AC Watt increase/min: not reported LC Watt increase: not reported Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 4

Ramonatxo, M. er al. (1996).

Title Differences in mouth occlusion pressure and breathing pattern between arm and leg incremental exercise.

Methods Cross-sectional study Participant Eight normal male subjects. No subjects were involved in exercise training but all status maintained their accustomed exercise training.

Group n=8 Gender (M/F): only males Age: 20-35 Heigh: 167-183 cm Weight: 60-80 kg Study protocol AC or LC tested first: Random Time between tests: Within one week AC Start Watt: 25 LC Start Watt: 50 AC Watt increase/min: 6.25 LC Watt increase: 12.5

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APPENDIX 2. Detailed characteristics of included studies (continued)

Outcomes of interest Risk of bias Notes

VO2max SumQAT: 3

Rรถsler, K. et al (1985) Title Transfer effects in endurance exercise.

Methods Trial Participant Ten healthy male subjects with a mean age of 30.5 (23-37) years, a mean height of 178 status (172-182) cm and a mean bodyweight of 70.8 (64-83) kg. None of them had been involved in regular training during the preceding two years, although some of then did some recreational jogging or cycling.

Group n= 10 Age: 30.5 (23-37) years Gender (M/F): only males Bodyweight: 70.8 (64-83) kg.

Height: 178 (172-182) BMI: 22.35 kg/m2 Study protocol AC or LC tested first: not reported Time between tests: not reported AC Start Watt: 40 LC Start Watt: 100 AC Watt increase/min: 6.667 W/min LC Watt increase: 17.5 W/min Outcomes of interest Risk of bias Notes

VO2max SumQAT: 4

Sargeant, A. J., & Davies, C. T. M. (1973).

Title Perceived exertion during rhythmic exercise involving different muscle mass Methods Cross-sectional study Participant Six healthy male subjects. All of the subjects had taken part of physiological status investigations before and were habituated to the exercise modalities in the study. All of the physical characteristics are given individually. The age ranges from 24-39 years, the height ranges from 171.8-189.0 cm and the bodyweight from 63.0-98.0 kg.

Group n= 6 Sex (M/F) = 6/0 Age: 30.6 5.53 years Gender (M/F): only males Bodyweight: 79.1 kg Height: 179.4 5.98 cm BMI: 24.58 kg/m2 Study protocol AC or LC tested first: not reported Time between tests: not reported

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APPENDIX 2. Detailed characteristics of included studies (continued)

AC Start Watt: not reported LC Start Watt: not reported AC Watt increase/min: not reported LC Watt increase: not reported Outcomes of interest Risk of bias Notes

VO2max SumQAT: 2

Sawka, M. N. Et al. (1983) Title Physiological factors affecting upper body aerobic exercise Methods Cross-sectional study Participant Nine male subjects. status Group n= 9 Sex (M/F): 9/0 Gender (M/F): only males Gender (M/F): 1/0 Bodyweight: 79.8 7.8 kg Study protocol AC or LC tested first: AC Time between tests: Two weeks AC Start Watt: not reported LC Start Watt: not reported AC Watt increase/min: not reported LC Watt increase: not reported Outcomes of interest Risk of bias Notes

VO2max SumQAT: 2 The study reports a correlation coefficient between AC and LC on r = 0.94.

Sharp, M. A. et al. (1988) Title Maximal aerobic capacity for repetitive lifting: comparison with three standard exercise testing modes Methods Cross-sectional study Participant 18 male subjects. status Group n= 18 Gender (M/F): only males Age: 23.9 3.7 years Bodyweight: 75.9 8.8 kg Height: 177.7 8.9 kg BMI: 24.04 kg/m2 AC RER: 1.19 0.11 LC RER: 1.21 0.09 Study protocol AC or LC tested first: not reported

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APPENDIX 2. Detailed characteristics of included studies (continued)

Time between tests: not reported AC Start Watt: not reported LC Start Watt: not reported AC Watt increase/min: not reported LC Watt increase: not reported

Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 2

Shiomi, T. et al. (2000) Title Physiological responses and mechanical efficiency during different types of ergometric exercises.

Methods Cross-sectional study Participant Seven healthy male. No subjects were performing regular exercise and none had status orthopaedic diseases. The subjects performed the tests at least two hours after the last meal and did not exercise before the tests.

Group n= 7 Gender (M/F): only males Age: 32.1 (27-36) years Bodyweight: 64.1 (54-73) kg Height: 169.9 (163-180) cm BMI: 22.21 kg/m2 Study protocol AC or LC tested first: not reported Time between tests: not reported AC Start Watt: 20 LC Start Watt: 20 AC Watt increase/min: 20 W/min LC Watt increase: 20 W/min Outcomes of interest Risk of bias Notes

VO2max SumQAT: 4 The study reports a correlation coefficient between AC and LC on r = 0.78.

Sporer, B. C. et al. (2007) Title Entrainment of breathing in cyclists and non-cyclists during arm and leg exercise Methods Cross-sectional study Participant Eight control subjects. status Group n= 8 Gender (M/F): only males Age: 26 5 years years Bodyweight: 82.8 8.1 kg

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APPENDIX 2. Detailed characteristics of included studies (continued)

Height: 184.5 6.5 cm BMI: 24.32 kg/m2 Study protocol AC or LC tested first: Random Time between tests: 60 minutes AC Start Watt: 15 LC Start Watt: 30 AC Watt increase/min: 15 W/min LC Watt increase: 30 W/min Outcomes of interest Risk of bias Notes

VO2max SumQAT: 5

Swensen, T. C., & Howley, E. T. (1993) Title Effect of one- and two-leg training on arm and two-leg maximum aerobic power Methods RCT Participant 21 untrained college-age men participated. They had a mean age of 22.8 (19-32) years status and a mean bodyweight of 73 (45-91) kg.

Age: not reported Gender (M/F): only males AC RER: 1.16 0.02 LC RER: 1.16 0.04

1.

0.07 1.18 0.07

1.16 0.06 1.22 0.05

Study protocol AC or LC tested first: LC Time between tests: at least 20 minutes AC Start Watt: 70 LC Start Watt: 120 AC Watt increase/min: 10 W/min LC Watt increase: 15 W/min Outcomes of interest Risk of bias Notes

VO2max and RER SumQAT: 5

Turner, D. L. et al. (1997) Title Effects of endurance training on oxidative capacity and structural composition of human arm and leg muscles.

Methods Trial Participant Six healthy male subjects. None of the subjects trained systematically although they were status recreationally active.

Group n= 6 Gender (M/F): only males Age: 23 years

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APPENDIX 2. Detailed characteristics of included studies (continued)

Bodyweight: 75 2 kg Height: 179 1 cm BMI: 23.41 kg/m2 Study protocol AC or LC tested first: not reported Time between tests: not reported AC Start Watt: 54 LC Start Watt: 50 AC Watt increase/min: not reported LC Watt increase: not reported Outcomes of interest Risk of bias Notes

VO2max SumQAT: 6

Warren, G. L. et al. (1990) Title Is gender difference in peak VO2 greater for arm than leg exercise?

Methods Cross sectional study Participant The untrained subjects had not participated in any form of regular aerobic exercise or status strength training three months prior to the study.

Group n= 10 Gender (M/F): only females Age: 25.1 2.8 years Bodyweight: 54.3 kg Height: 161 4 cm BMI: 20.95 kg/m2 Study protocol AC or LC tested first: Random Time between tests: two days AC Start Watt: 6-12 LC Start Watt: 30-47 AC Watt increase/min: not reported LC Watt increase: not reported Outcomes of interest Risk of bias Notes

VO2max SumQAT: 5

Yasuda, N., et al. (2008) Title No gender-specific differences in mechanical efficiency during arm or leg exercise relative to ventilatory threshold Methods Cross sectional study Participant The women had a mean age of 23.4 3.6 years, mean BMI 22.8 2.1 units, a mean height status of 167.3 6.2 cm and a mean bodyweight of 63.6 5.5 kg.

Group n=9

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APPENDIX 2. Detailed characteristics of included studies (continued)

Gender (M/F): only females Age: 23.4 3.6 years Bodyweight: 63.6 5.5 kg Height: 167.3 6.2 cm BMI: 22.28 2.1 kg/m2 AC RER: 1.08 0.05 LC RER: 1.12 0.06 Study protocol AC or LC tested first: Random Time between tests: Within 14 days AC Start Watt: 20 LC Start Watt: 97 AC Watt increase/min: 5 W/min LC Watt increase: 18 W/min Outcomes of interest Risk of bias Notes

VO2max SumQAT: 5

Yasuda, N., et al. (2006) Title Substrate oxidation during incremental arm and leg exercise in men and women matched for ventilator threshold Methods Cross sectional study Participant The subject performed low intensity exercises, such as running og cycling, for less than 1 status hour per week for a maximum of 4 times per week.

Group n=10 Gender (M/F): 0/10 Age: 23.4 3.4 years Bodyweight: 62.5 6.2 kg Height: 166 7 cm BMI: 22.68 kg/m2 AC RER: 1.10 0.07 LC RER: 1.12 0.06 Study protocol AC or LC tested first: Random Time between tests: Within 7 days AC Start Watt: 20 LC Start Watt: 97 AC Watt increase/min: 5 W/min LC Watt increase: 18 W/min Outcomes of interest Risk of bias Notes

VO2max SumQAT: 5

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APPENDIX 3. Detailed risk of bias assessment

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IJSPT

ORIGINAL RESEARCH

THE EFFECTS OF INSTRUMENT ASSISTED SOFT TISSUE MOBILIZATION ON LOWER EXTREMITY MUSCLE PERFORMANCE: A RANDOMIZED CONTROLLED TRIAL Nicole MacDonald, DrPH, ATC, CSCS1 Russell Baker, DAT, ATC2 Scott W. Cheatham, PhD, DPT, PT, OCS, ATC, CSCS3

ABSTRACT Background: Instrument-Assisted Soft Tissue Mobilization (IASTM) is a non-invasive therapeutic technique used to theoretically aid in scar tissue breakdown and absorption, fascial mobilization, and improved tissue healing. Researchers have hypothesized that utilizing IASTM will improve muscular efficiency and performance; yet previous Investigations has been focused on treating injury.

Objective: The purpose of this investigation was to explore the effects of IASTM on muscle performance to assess if typical treatment application affected measures of muscular performance.

Design: A pretest-posttest randomized control design.

Participants: A convenience sample of 48 physically active adults (mean age 24Âą4 years), randomly assigned to one of three groups: quadriceps treatment group, triceps surae treatment group, or control group.

Interventions: Participants performed a five-minute warm-up on a Monark bicycle ergometer before performing three countermovement vertical jumps (CMJ). Immediately after, the IASTM treatment was applied by one researcher for three minutes on each leg at the specified site (e.g., quadriceps) for those assigned to the treatment groups, while the control group rested for six minutes. Immediately following treatment, participants performed three additional CMJs. Pre- and post-testing included measures of vertical jump height (JH), peak power (PP) and peak velocity (PV).

Results: There were no statistically significant differences found between treatment groups in JH, PP, or PV or across pre- and post-test trials.

Conclusions: These preliminary findings suggest that standard treatment times of IASTM do not produce an immediate effect in muscular performance in healthy participants. This may help clinicians determine the optimal sequencing of IASTM when it is part of a pre-performance warm-up program. Future research should be conducted to determine the muscle performance effects of IASTM in individuals with known myofascial restriction and to determine optimal treatment parameters, such as instrument type, amount of pressure, and treatment time necessary to affect muscular performance.

Level of Evidence: 1b Keywords: Massage, myofascial release, instrument-assisted

1

California Baptist University, Riverside, CA, USA University of Idaho, Moscow, ID, USA 3 California State University Dominguez Hills, Carson, CA, USA 2

CORRESPONDING AUTHOR Nicole MacDonald California Baptist University 8432 Magnolia Ave. Riverside, CAÂ 92504 (951) 343-4379 E-mail: nmacdona@calbaptist.edu

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INTRODUCTION The myofascial system is a complex network of muscles and related fascia. Fascia is comprised of elastin and collagen connective tissue fibers that form sheets or bands beneath the skin that serves to attach, stabilize, enclose, and separate muscles, internal organs, and bones.1,2 The fascial network runs continuously throughout the body and consists of three layers: superficial, deep, and subserous. Each layer has its own unique properties that contribute to the overall function of the myofascial system.2 The myofascial system is thought to aid in force transmission of muscles, fibroblastic activity, proprioception, nociception, and reducing compartmental friction during movement through sliding of the fascial layers.1,2 Restriction within the myofascial system may occur due to injury, poor posture, or lack of full range of joint motion.1 The use of Instrument Assisted Soft Tissue Mobilization (IASTM) has become common by sports medicine professionals for treatment of myofascial restrictions. IASTM is a soft-tissue treatment technique where an instrument is used to provide a mobilizing stimulus to positively affect scar tissue and myofascial adhesion.11, 12 The use of the instruments, as opposed to a clinician’s hands, is theorized to provide a mechanical advantage to the clinician by allowing deeper penetration and possibly increasing specificity of treatment application,13 while also reducing imposed stress of treatments on the clinician’s hands.14,15 Application of IASTM is theorized to stimulate connective tissue remodeling through resorption of excessive fibrosis, along with inducing repair and regeneration of collagen secondary to fibroblast recruitment.11,16 In turn, this may result in breakdown of scar tissue, the release of adhesions, and improvement in fascial restrictions.3,4,11,12,14,17 There are several different approaches to IASTM, each of which provide their own tools and certification or training programs. Two of the more popular approaches are the Graston® Technique and Técnica Gavilán®. The body of literature on IASTM is still emerging, with the bulk of the research being case reports and case studies5-17 and a few controlled trials.14,18-21 IASTM has been found to be effective in improving range of motion and patient function in patients with chronic musculoskeletal pathology;7,14,21-23 however, only a single

study has been conducted that assesses the effects of IASTM on muscle performance (i.e., muscular force production and activation). The authors of that study found that IASTM application could improve muscular performance of the quadriceps muscle group when measured isometrically.24 Unlike other myofascial interventions, such as self-myofascial release, there is a gap in the knowledge about the effects of IASTM on muscle performance (e.g., power) and any potential detrimental effects that may occur if applied to the lower extremity pre-performance. Based on the literature and proposed mechanism of IASTM, it is hypothesized that the intervention will not have a detrimental effect on muscle performance and may actually promote improvements if applied to the quadriceps and triceps surae muscle groups. The purpose of this investigation was to explore the effects of IASTM on muscle performance to determine if typical treatment application affected measures of muscular performance.

METHODS This study was approved by California Baptist University’s Institutional Review Board (IRB# 12-49).

Eligible participants read and signed an informed consent prior to enrollment in this study. The present study utilized a pretest-posttest randomized control study design.

Subjects A convenience sample of 48 physically active adults was recruited for this investigation. The participants ranged in age from 19-39 (mean = 24±4 years), 58.3% (n=28) female and 42% (n=20) male. Most participants engaged in occasional vigorous exercise (47.9%), defined as “work or recreation, less than 4x/ week for 30 minutes,” and were not considered obese (mean Body Mass Index = 24.9 kg/m2)25 (Table 1).

Only participants classified as low to moderate risk were included in the study as determined by the Par Q and You.26 Participants were excluded if they had any current injuries that affected their integument or soft-tissue structures in the regions of treatment, dizziness, chest pain, or known heart conditions.

Participants were randomly assigned to one of three groups using a random number generator to ensure equal numbers in each group: IASTM Quadriceps treatment group (QG) (n = 16), IASTM Triceps Surae treatment group (TS) (n = 16), or control group (CG)

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Table 1. Summary of Participant Demographics

(n = 16). It was not possible to blind the participants or the practitioner applying the IASTM treatments, however, the researcher collecting the vertical jump data was blinded to which group the participant was assigned. Each participant completed a short demographic questionnaire and biometric measurements were taken before beginning the study.

Instruments The IASTM treatment was applied using Técnica Gavilán instruments (Tracy, CA) by one practitioner (RB) certified by Técnica Gavilán and with 10 years’ experience treating patients with the instruments.

The practitioner was blinded to the results of the study. Another blinded rater (AC) measured standing vertical jumps with the Tendo power analyzer

(Tendo Sport Machines, Slovak Republic) and Vertec Vertical Jump Training system (Jump USA, Sunnyvale, CA). Both the Tendo power analyzer (test-retest reliability = 0.97) and Vertec system (test-retest reliability = 0.91)27 are reliable measures. Another researcher (NM) ensured blinding of the treating and rating researchers, collected all in-take data (e.g., activity level, BMI, etc.), and analyzed the data.

Procedures All participants underwent pre-test measures, IASTM or control intervention, and post-test measures in one session (Table 2). Prior to testing, participants performed a five-minute warm-up on a Monark bicycle ergometer. Pre and post-intervention testing consisted of three standing vertical jumps measured by a Tendo

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Table 2. Consort Flow Chart

power analyzer attached to the participant while performing a countermovement vertical jump with the Vertec Vertical Jump Training system. The participant’s standing height was first measured using the Vertec by recording the highest vane touched by their raised right hand (Figure 1). After the standing height value was recorded, the Tendo power analyzer cable and belt were attached to the participant, who was then asked to jump and hit the highest target vane possible on the Vertec with their right hand (Figure 2). The participant completed three consecutive jumps resting no more than 10 seconds in between, and the height of each jump, the peak power (PP), and peak velocity (PV) were recorded as baseline. Maximum jump height was recorded as the highest vane moved (cm) by the participant on the Vertec, and PP(watts) and PV(m/sec) were measured using the Tendo power analyzer. Only the best attempt of the three was taken for data analysis.

Immediately after obtaining baseline measures, the IASTM treatment was applied bilaterally, left leg

first for each participant, for three minutes on each leg at the specified site (i.e., quadriceps or triceps surae) for those assigned to the treatment groups.

The quadriceps group received direct IASTM treatment to the rectus femoris, vastus lateralis and vastus medialis, with indirect treatment to the vastus intermedius (Figure 3). The triceps surae group received direct IASTM treatment to the gastrocnemius, with indirect treatment to the soleus and plantaris (Figure 4). The IASTM application began with ultrasound gel application to the treatment area and included general “sweeping” strokes from origin or insertion of each muscle group, without specific treatment strokes to any specific area in the muscle group. Each muscle group was treated with the participant in a resting position (i.e., quadriceps group in a long sitting position and triceps surae group in prone position with foot in slight plantarflexion).

The practitioner attempted to maintain consistent instrument angle (~45°) and pressure (~250g) throughout the treatment. The control group rested

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Figure 3. IASTM (Tecnica Gavilan, Tracy, CA) Treatment to Quadriceps

Figure 1. Standing Height Measurement with the Vertec Standing Vertical Jump Training System (Jump USA, Sunnyvale, CA) Figure 4. IASTM (Tecnica Gavilan, Tracy, CA) Treatment to the Triceps Surae Group

for six minutes between testing periods by sitting in a chair. Immediately following the IASTM treatment, participants performed three additional standing vertical jumps following the same procedure from the baseline measurement.

Figure 2. Standing Vertical Jump Analysis using Vertec Vertical Jump Training System (Jump USA, Sunnyvale, CA) and Tendo Power Analyzer (Tendo Sport Machines, Slovak Republic)

Statistical Analysis All participants that were deemed eligible to participate completed the study and all data were analyzed utilizing SPSS (v. 22, Chicago Ill.) using a repeated measures design. The analysis used to test the primary hypothesis was an Analysis of Variance with three groups. As previous research did not exist to guide effect size selection for a power analysis, Cohenâ&#x20AC;&#x2122;s26 guidelines of an estimation of a large effect size (f = 0.4), 80% power, and Îą = 0.05 were utilized; it was concluded that 21 participants were needed in each group for a total of 63 participants. Descriptive statistics included means and standard deviations for continuous data (age, height, weight, BMI, and body fat percentage) and frequencies for categori-

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Table 3. Comparison between mean scores for pre and post measurements by treatment group. Values are represented as mean ± SD

cal data (gender and level of physical activity) were calculated (Table 1). Differences between group variables were calculated with an ANOVA. Vertical jump height (JH) was calculated by subtracting the participant’s standing height from the best of the three jumps before and after treatment. A betweensubject factorial ANOVA was conducted to compare the effects of IASTM (QG, TS, and CG) on JH, PP, and PV before and after treatment. The p-value was considered significant at p<0.05.

RESULTS No statistically significant differences (p<0.05) between groups for JH, PP, or PV at baseline were identified [JH: F(2,45)=1.065, p=0.323, η2=0.045; PP: F(2,45)=1.277, p=0.289, η2=0.054; PV: F(2,45)=1.221, p=0.305, η2=0.051.] There were no significant main effects for time [JH : F(1,45)=0.09, p=0.765, partial η2=0.002; PP: F(1,45)=0.092, p=0.763, partial η2=0.002; PV: F(1,45)=0.241, p=0.626, partial η2=0.005], nor any significant interaction effects for time*group [JH: F(2,45)=0.751, p=0.478, partial η2=0.032; PP: F(2,45)=0.123, p=0.885, partial η2=0.005; PV: F(2,45)=0.146, p=0.865, partial η2=0.006] (Table 3).

DISCUSSION The effects of IASTM on muscle performance measured by vertical jump height, peak power, and peak velocity were examined in this study. No significant

differences between treatment groups were found when using the current IASTM treatment parameters. The IASTM treatment in this study was applied for three-minutes to reflect current IASTM protocols which typically include short treatment times (e.g., one to five minutes) per treatment location.12,16-19 Donahue24 previously found that IASTM application on the quadriceps muscle group increased isometric force production, while also decreasing muscle activation (percent maximal voluntary isometric contraction) in healthy, college-aged students. Participants were treated with four one-hour IASTM treatments over a one-week period (Days 1, 3, 5, and 7); improvements in muscular contraction efficacy were found between treatment sessions (e.g., pretreatment Day 1 post-treatments Day 3, 5, and 7) and over the full course of treatment for the quadriceps muscles (i.e., rectus femoris, vastus lateralis, and vastus medialis oblique). While it is possible that the differences in instruments (e.g., instrument weight, angle of instrument edge, surface area, etc.) or treatment administration (e.g., force application) may have resulted in the different findings, the most obvious difference in this study was treatment duration and the length of the assessment period.24 To produce meaningful change in muscle performance it may be necessary to provide longer IASTM treatment times. Given the different findings, it may be that a longer treatment time, increased pressure dur-

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ing application, or multiple treatments are needed to improve muscle performance enough to significantly change vertical jump performance or other measures of muscular performance. Drawing accurate conclusions on this topic is difficult and more research is needed to determine the effect of IASTM on muscular performance.

Limitations This investigation contains several limitations that warrant discussion. First, this investigation used a convenience sample of healthy participants and did not reach the estimated sample size. It is possible the lack of statistical significance is a result of the sample size or a smaller treatment effect than expected.

The results of this study, however, serve as a useful guide for designing follow-up studies and calculating an appropriate sample size. Second, the participant group ranged from 19-39 (mean = 24 ± 4 years) years of age; the results of this study can only be generalized to healthy participants within this age group. Third, this study utilized more global measures of lower extremity muscle performance (e.g., vertical jump) and did not measure performance of specific lower extremity muscles; it is possible that treating more than one muscle group may be necessary to improve these measures. The additional use of isokinetic dynamometry or electromyography may have provided further insight into the performance of specific muscles.26 Both global and isolated measures should be considered in future research to obtain a more comprehensive understanding of the effects of the intervention.

Clinical Implications Despite these limitations, these data suggest that standard treatment times of IASTM do not affect muscle performance. For the clinician, this data provides some preliminary evidence that may help in determining the optimal sequencing of IASTM when it is part of a comprehensive rehabilitation program for individuals with myofascial dysfunction. Clinicians may want to include IASTM as part of their treatment regime; IASTM is a skilled intervention provided by the clinician. Based on the current evidence, it does not appear that IASTM will negatively impact muscular performance if utilized prior to athletic performance; however, the paucity

of evidence makes it difficult to suggest that this intervention may be beneficial to measures of muscular performance.

CONCLUSIONS IASTM is a popular myofascial intervention that is incompletely described with regard to its effects on muscle performance. The purpose of this research was to determine the effect of an IASTM treatment on lower extremity muscle performance, and no significant differences were found among groups suggesting such intervention will not detrimentally affect lower extremity muscle performance when used as a pre-exercise intervention. Future research should focus on determining the muscle performance effects of IASTM on individuals with a known myofascial pathology. Future research should also seek to determine the optimal treatment parameters such as type of instrument, amount of pressure, and treatment time for different pathologies.

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14. Sevier TL, Stegink-Jansen CW. Astym treatment vs. eccentric exercise for lateral elbow tendinopathy: a randomized controlled clinical trial. PeerJ. 2015;3:e967.

15. Strunk RG, Pfefer MT, Dube D. Multimodal chiropractic care of pain and disability for a patient diagnosed with benign joint hypermobility syndrome: a case report. J Chiropr Med. 2014;13(1):35-42.

16. Lee JJ, Lee JJ, Kim do H, You SJ. Inhibitory effects of instrument-assisted neuromobilization on hyperactive gastrocnemius in a hemiparetic stroke patient. Biomed Mater Eng. 2014;24(6):2389-2394.

17. White KE. High hamstring tendinopathy in 3 female long distance runners. J Chiropr Med. 2011;10(2):9399.

18. Braun M, Schwickert M, Nielsen A, et al.

Effectiveness of traditional Chinese “gua sha” therapy in patients with chronic neck pain: a

19.

20.

21.

22.

23.

24.

25.

26.

randomized controlled trial. Pain Med. 2011;12(3):362-369.

Laudner K, Compton BD, McLoda TA, Walters CM. Acute effects of instrument assisted soft tissue mobilization for improving posterior shoulder range of motion in collegiate baseball players. Int J Sports Phys Ther. 2014;9(1):1-7.

Markovic G. Acute effects of instrument assisted soft tissue mobilization vs. foam rolling on knee and hip range of motion in soccer players. J Bodyw Mov Ther.

2015;19(4):690-696.

Schaefer JL, Sandrey MA. Effects of a 4-week dynamic-balance-training program supplemented with Graston instrument-assisted soft-tissue mobilization for chronic ankle instability. J Sport Rehabil. 2012;21(4):313-326.

Baker RT, Nasypany A, Seegmiller JG, Baker JG. Instrument-Assisted Soft Tissue Mobilization Treatment for Tissue Extensibility Dysfunction. Int J Athl Ther Train. 2013;18(5):16-21.

Wilson JK, Sevier TK, Helfts R, Honing EW, Thomann A. Comparison of Rehabilitation methods in the Treatment of Patellar Tendinitis. Journal of Sport Rehabilitation. 2000;9(4):304.

Donahue M. The Effect of the Graston Technique on Quadracieps [i.e. Quadriceps] Muscle Activation and Force Production. Indiana University, Department of Kinesiology; 2008.

Garber CE, Blissmer B, Deschenes MR, et al.

American College of Sports Medicine position stand.

Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise. Med Sci Sports Exerc. 2011;43(7):1334-1359.

Bennett DR, Blackburn JT, Boling MC, McGrath M, Walusz H, Padua DA. The relationship between anterior tibial shear force during a jump landing task and quadriceps and hamstring strength. Clin Biomech (Bristol, Avon). 2008;23(9):1165-1171.

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IJSPT

ORIGINAL RESEARCH

IMMEDIATE EFFECTS OF DEEP TRUNK MUSCLE TRAINING ON SWIMMING START PERFORMANCE Satoshi Iizuka, MS1 Atsushi Imai, PhD2 Keisuke Koizumi, MS3 Keisuke Okuno, MS2 Koji Kaneoka, MD, PhD2

ABSTRACT Background: In recent years, deep trunk muscle training has been adopted in various sports, including swimming. This is performed both in everyday training and as part of the warm-up routine before competitive races.

It is suggested that trunk stabilization exercises are effective in preventing injury, and aid in improving performance. However, conclusive evidence of the same is yet to be obtained. The time of start phase of swimming is a factor that can significantly influence competition performance in a swimming race.

Hypothesis/Purpose: If trunk stabilization exercises can provide instantaneous trunk stability, it is expected that they will lead to performance improvements in the start phase of swimming. The purpose of this study was to investigate the immediate effect of trunk stabilization exercises on the start phase in swimming.

Study Design: Intervention study Methods: Nine elite male swimmers (mean age 20.2 ± 1.0 years; height 174.4 ± 3.5 cm; weight 68.9 ± 4.1 kg) performed the swimming start movement. The measurement variables studied included flying distance, and the time and velocity of subjects at hands’ entry and on reaching five meters.

Measurements were taken in trials immediately before and after the trunk stabilization exercises. A comparison between pre- and post-exercise measurements was assessed.

Results: The time to reach five meters (T5m) decreased significantly after trunk stabilization exercises, by 0.019 s (p=0.02). Velocity at entry (Ventry) did not demonstrate significant change, while velocity at five meters (V5m) increased significantly after the exercises (p=0.023). In addition, the speed reduction rate calculated from Ventry and V5m significantly decreased by 5.17% after the intervention (p=0.036).

Conclusion: Trunk stabilization exercises may help reduce the time from start to five meters in the start phase in swimming. The results support the hypothesis that these exercises may improve swimming performance.

Levels of Evidence: Level 3b Keywords: Competitive swimmer, intervention, speed reduction

1

Graduate School of Sport Sciences, Waseda University, Saitama, Japan 2 Faculty of Sport Sciences, Waseda University, Saitama, Japan 3 Tokyo College of Sports and Recreation, Tokyo, Japan

CORRESPONDING AUTHOR Koji Kaneoka, MD, PhD Faculty of Sport Sciences, Waseda University, Saitama, Japan 2-579-15 Mikajima, Tokorozawa Saitama, 359-1192, Japan Phone: +81-4-29476958 E-mail: kaneoka@waseda.jp

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INTRODUCTION The deep trunk muscles, such as the transversus abdominis and the internal oblique, play an important role in stabilizing the trunk. Several researchers have reported that exercising these muscles enhances performance and prevents injuries.1-5 Based on the results of these studies, stabilization exercises aimed at training deep trunk muscles are considered fundamental to exercises programs for strength and conditioning.6 In recent years, the stabilization exercises have come to be prescribed for athletes in a variety of sports.

Because the trunk centers the movement of the extremities through the swimming motion, increased trunk stability, led by the deep trunk muscles, may improve performance.7 Trunk stabilization exercises are often performed by swimmers as part of their daily routine, and for pre-race warm-up. A study by Weston et al has already shown the beneficial effects of trunk stabilization exercises on 50 m front crawl times.5 A swimming race may be divided into four phases: start, stroke, turn, and finish. Since the highest acceleration is gained during the start phase, it is critical in determining overall swimming performance.8, 9 In the start phase, swimmers kick back against plates on the starting block to increase horizontal speed.

Preliminary research, focusing on the lower limbs at the start, showed that performance improved immediately when lower-limb training was performed as part of the warm-up.10 Additionally, the deceleration due to water resistance at the moment of entry is important and if able to be minimized could be beneficial for overall time reduction.

It has been reported that facilitation of the deep trunk muscles increases stability of the body.11 Due to the increase in stability, it is postulated that the body becomes more rigid. Authors have described the influences of stability on the body as important to the control of a variety of movements.12,13 Trunk stability is essential in order to gain high start velocity and reduce water resistance during diving.

Increased rigidity of the trunk can assist in efficient transmission of the propulsion force from the body to the back plates. The trunk muscles also help to maintain streamlined, which reduces water resistance during entry. If stabilization exercises can

provide instantaneous trunk stability, enhanced performance in the start phase may be expected. Previous researchers have demonstrated the immediate effect of trunk stabilization exercises in improving performance on the rebound jump that repeats the vertical jump with a countermovement arm swing.14 If trunk stabilization exercises can provide instantaneous trunk stability, it is expected that they will lead to performance improvements in the start phase of swimming. The purpose of this study was to investigate the immediate effect of trunk stabilization exercises on the start phase in swimming.

METHODS Participants Nine elite male swimmers (mean age 20.2 Âą 1.0 years; height 174.4 Âą 3.5 cm; weight 68.9 Âą 4.1 kg) from the University swimming team took part in the study. All participants were experienced, nationallevel swimmers. The swimming style of the participants was not considered. Swimmers who had pain or injuries in any of the body parts that influenced swimming were excluded. All participants were provided with, and signed, written informed consent forms before participation. The study was approved by the Ethical Committee of Waseda University.

Procedures The starting block used in this study was manufactured by Seiko (Tokyo, Japan). For each subject, the position of the movable back plate on the starting block was adjusted to a race setting. Two highspeed video cameras (HAS-220, DITECT Co., Tokyo Japan) were used to record the starting motion. One camera was placed on the side of the starting block, while the other was placed five meters away from the starting block, in the water. Recording frequency was set at 200 frames per second. Eight self-emitting LED markers (Kirameki, Nobby Tech. Ltd., Tokyo, Japan) were attached on anatomical landmarks on the right side of the subjects at the ulnar styloid process, the olecranon, the acromion, the anterior superior iliac spine, the posterior inferior iliac spine, the great trochanter, the head of the fibula and the lateral malleolus. By tracking each marker, the starting motion was analyzed using three-dimensional motion analysis software (Frame-DIAS V, DKH Co., Ltd., Tokyo, Japan). Prior to measurement, subjects

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were allowed a warm-up session of approximately 10 minutes, for the starting motion. Two or more repetitions starting motions were included in the warm-up. For the measurement, subjects performed the starting motion, cued by the starting signal used in race conditions. After the first starting trial (preexercise measurement), the subject performed the trunk stabilization exercises. The starting trial was repeated immediately after the exercises (postexercise measurement). A previous study showed reliability and validity of the procedure used for measurements and analysis in water.15 Variables The study assessed performance of the starting motion for distance, time, and velocity. Flight distance (L) was measured as the distance from the wall of the pool to the point where the hands enter the water. The timing of hand enter was defined when the fingertip touched the water surface. The timing was confirmed visually from the view of camera in the water. In the same way, reaching five meters was also judged when the fingertip reached a distance five meters from the same camera.

Figure 1. Diagram of the definitions of variables. L is the flight distance from wall to entry point of the hands. Tflight is the time from the take-off to entry. Twater is the time from the hands entry to the hand crossing the imaginary line at five meters. T5m is the summed time of Tflight and Twater. Ventry is magnitude of the velocity of the great trochanter marker at the hands entry. V5m is magnitude of the velocity of the great trochanter marker at the hand crossing the imaginary line at five meters.

This value was calculated after conversion into real length from a moving image using two-dimensional Direct Linear Transformation (DLT) method.16 To measure time, the starting motion was divided into two phases. The first phase named the flight phase (Tflight), was defined as the time between the back foot taking off and the hands’ entry into the water..

The second phase, named the water phase (Twater), was defined as the time from the hands’ entry into the water to reaching five meters. The sum of Tflight and Twater represents the total time, T5m. In addition, the instantaneous velocity at entry (Ventry) and at five m (V5m) were calculated by tracking the LED marker on the greater trochanter (Figure 1).

Intervention The pilot study demonstrated that trunk stabilization exercises may activate deep trunk muscles.17 There were three trunk stabilization exercises used during the study namely, the elbow-knee position held for 60 seconds, the alternating arm raise in the elbow-knee position for 30 repetitions, and the alternating leg raise in the elbow-knee position for 30 repetitions (Figure 2). A resting time of 15 seconds

Figure 2. Stabilization exercises intervention; (a) elbow-knee (held for 60sec), (b) elbow-knee with alternative arm raise (30 times), (c) elbow-knee with alternative leg raise (30 times)

was allocated between exercises. These exercises are also used by the Japanese national swim team as a pre-race warm-up (Figure 3). A previous study showed that 30 % of the maximum voluntary con-

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interpret the strength of the effect size was: 0-0.2 small; 0.2-0.6 moderate; >0.8 large.19

Figure 3. Actual warm up exercises performed before the swimming race in London Olympics.

traction (transversus abdominis: TrA) was sufficient to control the stability of lumber segments.18 Regarding trunk stabilization exercises, adequate activity of the deep trunk muscles was obtained by Hand-Knee exercise procedure.17 Based on the results of these studies, suitable interventions for swimming were chosen and employed in this study.

Statistical Analysis The average value and standard deviation of each performance variable were calculated. The pre-and post-exercise measurements were compared using a dependent t-test. Statistical analysis software (SPSS Statistics 21, IBM Japan Inc.) was used for the analysis, with the alfa level set at 5%. Effect size was calculated using Cohenâ&#x20AC;&#x2122;s d to establish the strength of the differences between each trial. The scale to

RESULTS Table 1 shows each performance variable, pre- and post-trunk stabilization exercises. The time, T5m, decreased significantly after the exercises, by 0.019 s (p=0.02), although there was no significant change in Tflight and Twater separately. Ventry did not demonstrate a significant change, although V5m increased significantly after the exercises (p=0.023). The rate of speed reduction calculated between Ventry and V5m decreased significantly, by 5.17% after the intervention (p=0.036). L did not show significant variation in the two measurements. (Figure 4) DISCUSSION Although trunk stabilization exercises have been used in a variety of sports disciplines, their effect on performance has not yet been clarified. This study investigated the effect of the trunk stabilization exercises on simulated race start performance.

Flight distance from the starting block to the point of water entry, and the time to reach the point of entry and then five meters, were used as performance values in this study. The results suggest that velocity at five meters from the start increased following stabilization intervention. However, trunk stabilization exercises did not alter the flight distance. An earlier study reported that trunk stabilization exer-

Table 1. Means and standard deviations obtained for each variable.

Abbreviations; L: the flight distance from wall to entry point of the hands. Tflight: the time from the take-off to entry. Twater: the time from the hands entry to the hand crossing the imaginary line of 5m.

T5m: the summed time of Tflight and Twater. Ventry: magnitude of the velocity at the hands entry. V5m: magnitude of the velocity at the hand crossing the imaginary line of 5m.

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Figure 4. Means and standard deviations obtained in the speed reduction rate.

cise interventions could immediately increase jump height measured in rebound jumps performed on the ground.14 However, the findings regarding the relationship between the vertical jump ability and starting performance in swimming are inconclusive. One study demonstrated a positive correlation between them.20 On the contrary, Ray et al reported that improvement of the vertical jump did not lead to enhancement in starting performance.21 The results of the present study indicate that trunk stabilization exercises did not have an immediate effect on the flight distance during the starting motion. The positive correlation between lower-limb warm-up exercises and flight distance observed in the authors earlier intervention allows conjecture that trunk stabilization exercises alone are insufficient in improving flight distance.10 The time taken to reach five meters, T5m, decreased by 0.019 s (p=0.02) after the exercises. This time reduction may be considered insignificant, but an improvement by 0.02 s is meaningful when results in a competitive swimming race may be decided by as little as one millisecond. For example, in results from a recent national race in japan, rank was changed by a difference of 0.02 s.

In addition to, V5m increased significantly. The preexercise V5m was 4.61 Âą 0.46 (m/s), but it became 4.87 Âą 0.35 (m/s) in the post-exercise measurement, confirming a significant improvement in speed (p=0.023). However, because Ventry remained unchanged after the intervention, trunk stabilization exercises may not affect the transmission of

propulsion force to the back plates on the starting block. A computer simulation model demonstrated that there was a strong resistance against the shoulders and thorax at the moment of entry moment.22 Unless the trunk maintains a stable, straight line during entry, swimmers greater water resistance, due to less streamlined in the water. This less streamlined can further increase water resistance and may lead to deceleration. Trunk stabilization exercises can quickly activate the deep trunk muscles in order to minimize unnecessary trunk movement against water resistance at entry. This suggestion is supported by the results, which show that the speed in the water was not decreased and higher velocity could be maintained at the five meter point.

The findings of this study support the hypothesis that trunk stabilization exercises may lead to immediate improvements in starting performance, and may reduce swimming race timing. An immediate improvement in performance indicators was observed even though the participants performed similar exercises in their daily routine. The results indicate the beneficial effects of including trunk stabilization exercises as part of the warm-up routine.

The applicability of the studyâ&#x20AC;&#x2122;s findings is somewhat limited by the lack of a control group comprised of people who do not exercise regularly. This study only investigated the acute/short term effects, and thus, it remains unknown how long the effects of these exercises last. Further research is required to clarify the effects of trunk stabilization exercises and how long it lasts on swimming performance.

Although participants performed same warm up procedure as a race, only one trial was measured at pre and post interventions respectively. Thus, it is difficult to negate a learning effect, which is a limitation of this study. In addition, since intensity of the training intervention was moderate level, there is a possibility that higher intensity programs may lead to superior results. A between-group design will be required for further study to confirm how much level of the intervention results in the best performance.

CONCLUSIONS Intervention in the form of trunk stabilization exercises may reduce the time from start to five meters

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in the start phase of swimming, which may improve overall swimming performance.

REFERENCES 1. Comerford MJ, Mottram SL. Functional stability re-exercises: principles and strategies for managing mechanical dysfunction. Man Ther. 2001;6(1):3-14.

2. Durall CJ, Udermann BE, Johansen DR, et al. The effects of preseason trunk muscle exercises on low-back pain occurrence in women collegiate gymnasts. J Strength Cond Res. 2009;23(7):86-92.

3. Nuzzo JL, McCaulley GO, Cormie P, et al. Trunk muscle activity during stability ball and free weight exercises. J Strength Cond Res. 2008;22:95-102.

4. Oliver GD, Di Brezzo R. Functional balance exercises in collegiate women athletes. J Strength Cond Res. 2009; 23(7):2124-2129.

5. Matthew Weston, Angela E. Hibbs, Kevin G. et al.

Isolated Core Exercises Improves Sprint Performance in National-Level Junior Swimmers. Int J Sports Physiol Perf. 2015;10:204-210.

6. Casey A. Reed, Kevin R. Ford, Gregory D. Myer, et al. The Effects of Isolated and Integrated ‘Core Stability’ Exercises on Athletic Performance Measures A Systematic Review. Sports Med. 2012;42(8):697-706.

7. Willardson JM. Core stability exercises: applications to sports conditioning programs. J Strength Cond Res. 2007;21(3):979-85.

8. Arellano R, Moreno F.J, Martínez M, et al. A device for quantitative measurement of starting time in swimming. Biomech Med Swim Ⅶ. 1996;195-200.

9. Mason B, Cossor J. What can we learn from competition analysis at the 1999 Pan Pacific Swimming Championships? In Proceedings of ⅩⅧ Symposium on Biomechanics in Sports. 2000; 75-82.

10. Cuenca-Fernández F, López-Contreras G, Arellano R. Effect on swimming start performance of two types of activation protocols: lunge and YoYo squat. J Strength Cond Res. 2015; 29(3):647-655.

11. Stanton T, Kawchuk G. The effect of abdominal stabilization contractions on posteroanterior spinal stiffness. Spine. 2008: 33(6):694-701.

12. Jonathan D. Mills, Jack E. Taunton, William A. Mills.

The effect of a 10-week training regimen on lumbopelvic stability and athletic performance in female athletes: A randomized-controlled trial. Phys Ther Sport. 2005; 6(2):60-66.

13. Kibler WB, Press J, Sciascia A. The role of core stability in athletic function. Sports Med. 2006; 36(3):189-98.

14. Imai A, Kaneoka K, Okubo Y, et al. Immediate Effects of Different Trunk Exercise Programs on Jump Performance. Int J Sports Med. 2016; 37(3):197-201.

15. Veiga, S, Cala, A, Gonzalez Frutos P, et al. The Validity and Reliability of a Procedure for Competition Analysis in Swimming Based on Individual Distance Measurements. XI Biomechanics and Medicine in Swimming. 2010; 182-184.

16. Hayashihara Y, Nishimura K. A study on the automated VTR motion analysis system by Two Dimensional DLT Method. Memoirs of the Faculty of Integrated Arts and Sciences, Hiroshima University. IV, Science reports : studies of fundamental and environmental sciences, 1995;21:161-169.

17. Okubo Y, Kaneoka K, Imai A, et al.

Electromyographic analysis of transversus abdominis and lumbar multifidus using wire electrodes during lumbar stabilization exercises. J Orthop Sports Phys Ther, 2010;40(11):743-750.

18. GA Jull, CA Richardson. Rehabilitation of active stabilisation of the lumbar spine. Physical Therapy of the Lumbar Spine 2nd ed. Churchill Livingstone. 1994; 251-283.

19. Cohen, J. Statistical power analysis for the behavioural sciences (2nd ed.). Academic Press, 1988 20. Pearson C.T., McElroy G.K., Blitvich J.D., et al. A comparison of the swimming start using traditional and modified starting blocks. J Hum Move Stud. 1998; 34:49-66.

21. Ray V.P. Breed, Warren B. Young. The effect of a resistance exercises programme on the grab, track and swing starts in swimming. J Sports Sci, 2003;21(3):213-220.

22. Kiuchi H, Nakashima M, Cheng K.B., et al. Modeling Fluid Forces in the Dive Start of Competitive Swimming. J Biomech Sci Engineering, 2010;5(4):314-328.

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IJSPT

ORIGINAL RESEARCH

CHANGES IN DYNAMIC BALANCE AND HIP STRENGTH AFTER AN EIGHT-WEEK CONDITIONING PROGRAM IN NCAA DIVISION I FEMALE SOCCER (FOOTBALL) ATHLETES Brandon M. Ness, PT, DPT, SCS, CSCS1 Brett A. Comstock, PhD, CSCS1 William E. Schweinle, PhD1

ABSTRACT Background: Lower extremity injury commonly affects female soccer athletes. Decreased dynamic balance and hip strength are identified risk factors for lower extremity injury. Little is known about how these factors adapt to a training stimulus in this population.

Purpose: To retrospectively investigate changes in lower extremity dynamic balance and isometric hip strength in Division I collegiate female soccer athletes after participating in an eight-week strength and conditioning program.

Study Design: Retrospective, non-experimental cohort study.

Methods: As part of a standard testing battery, soccer athletes completed athletic performance pre- and post-testing separated by an eight-week off-season conditioning program consisting of overall strength and technical skill development. Testing included lower extremity dynamic balance assessment through the Star Excursion Balance Test (SEBT) and isometric hip abduction and external rotation (ER) strength testing, normalized to limb length and percent body mass, respectively. Athletes rested for one week prior to post-testing.

Results: Seventeen healthy Division I female soccer athletes (age: 18.8 ± 0.9 years, height: 1.7 ± 0.06 m, mass: 68.0 ± 8.2 kg) completed the protocol. Significant improvements in SEBT composite reach distance were observed in the dominant (DOM) (3.6 ± 4.8%, 95% CI: 1.1 to 6.0) and nondominant (NDOM) (4.8 ± 6.1%, 95% CI: 1.7 to 7.9) limbs. Significant improvements in DOM hip ER strength (2.4 ± 2.3%, 95% CI: 1.3 to 3.6) and DOM SEBT anterior reach (2.1 ± 2.8%, 95% CI: 0.6 to 3.5) were observed.

Large effect sizes were observed for DOM and NDOM hip ER strength gains (0.87 – 1.0), while small-moderate effect sizes were noted for the anterior reach direction (0.40 – 0.66). Further, DOM hip ER strength gains were significantly associated with DOM anterior reach performance improvements (r2 =0.37, p<.01).

Conclusion: DOM hip ER strength gains appear to be associated with improved lower extremity dynamic balance on the ipsilateral limb for the SEBT anterior reach direction in collegiate, Division I female soccer athletes after an eight-week conditioning program. Future investigations should prospectively investigate intervention strategies to modify lower extremity injury risk factors in this population.

Level of Evidence: 2b Key Words: Dynamic balance, hip strength, soccer, women

1

University of South Dakota, Vermillion, SD, USA

Financial Disclosures: None Statement of the Institutional Review Board approval of the study protocol: “The study submission and informed consent for the proposal referenced above has been reviewed and approved via the procedures of the University of South Dakota Institutional Acknowledgements: Austin Stroeh, CSCS for sharing his strength and conditioning expertise Review Board: Your study has been granted a waiver of the process of informed consent.

CORRESPONDING AUTHOR Brandon Ness, PT, DPT, SCS, CSCS Department of Physical Therapy University of South Dakota 414 East Clark Street Vermillion, SD 57069 E-mail: Brandon.M.Ness@usd.edu

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INTRODUCTION Womenâ&#x20AC;&#x2122;s participation in soccer has dramatically increased recently;1 however, lower extremity injuries are a substantial concern for this population.2-4 Injury risk factors have been investigated with efforts to identify reliable, valid means of assessment. Through these efforts, many risk factors have been identified, which include but are not limited to previous injury,5 accumulated fatigue,5 decreased hip strength,6 and impaired lower extremity dynamic balance.7 Balance can be described as oneâ&#x20AC;&#x2122;s capacity to safely sustain or move within the existing base of support, through processing a combination of motor and sensory information.8 Lower extremity dynamic balance performance varies according to sport,9 patient population,10-14 and competition level.15 One common, accessible means for evaluating lower extremity dynamic balance is through the Star Excursion Balance Test (SEBT). This reliable test16,17 assesses postural control with the athlete in single limb stance, while reaching with the nonweightbearing limb in three predetermined directions. Lower extremity dynamic balance, as assessed through the SEBT, has been described across a wide variety of athletic populations at risk for lower extremity injury7,9,18 and has demonstrated improvement after a neuromuscular training program that included core stability exercises.19 SEBT performance is not only influenced by adequate postural control, but also ankle mobility20 and isometric hip external rotation (ER), extension, flexion, and abduction (ABD) strength.21,22 Impaired isometric hip ER strength has been identified as a risk factor for lower extremity injury in male and female intercollegiate cross-country and basketball athletes,23 and hip ABD and ER strength are each predictive of ACL injuries in a heterogeneous cohort of male and female competitive club futsal, soccer, volleyball, basketball, and handball athletes (odds ratio 1.12 â&#x20AC;&#x201C; 1.23).6 Various training programs have been utilized to address modifiable risk factors for athletic injury.

Impaired landing mechanics are associated with decreased isometric hip strength.24 However, landing strategies improved with a four-week, hipfocused training program consisting of plyometric,

balance, and core stability exercises.25 Additionally, multi-faceted training programs that include components of stretching, strengthening, plyometric training, and agility have been shown to decrease anterior cruciate ligament (ACL) injuries in female soccer athletes.26,27 In addition to injury risk modification, previous research has specifically focused on the influence of hip strengthening in various clinical populations.

In those with patellofemoral pain, hip strength and patient symptoms improved with an eightweek training protocol that utilized motor control and strengthening strategies for the trunk and hip regions.28 A similar outcome has been demonstrated in a similar patient population, with earlier patellofemoral pain reduction noted with hip strengthening prior to functional exercises when compared to quadriceps strengthening.29 Hip strengthening programs have also proven effective in postoperative rehabilitation. A focused hip strengthening program improved lower extremity dynamic balance in patients with ACL reconstruction at three months postoperative compared to a traditional program.30 The eight-week training program included a series of weightbearing and nonweightbearing hip strengthening exercises, selected based upon results of prior electromyographical (EMG) studies. It seems as though interventions targeting proximal lower limb motor control and strength may improve known risk factors for lower extremity injury, including dynamic balance and landing mechanics, in specific populations. Examining the influence of different exercise protocols on injury risk factors within distinct athletic populations may allow for a directed, impactful model of exercise prescription.

Many soccer team-based training programs include some aspect of hip strengthening, along with exercises to target overall strength, power, and speed development. Athletic performance testing of lower extremity dynamic balance and hip strength can provide useful information for training program design and implementation. Little is known about how lower extremity injury risk factors, specifically dynamic balance and hip strength, respond to a multi-faceted training program in elite female soc-

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cer athletes. The purpose of this study was to retrospectively investigate changes in lower extremity dynamic balance and isometric hip strength in Division I collegiate female soccer athletes after participating in an eight-week strength and conditioning program. The authors’ hypothesis was that lower extremity dynamic balance performance and hip strength would both improve with a multi-faceted training regimen.

METHODS This study was approved by the University of South Dakota Institutional Review Board. A waiver of consent was granted given the nature of this study. This study was a retrospective review of testing and sports performance records of National Collegiate Athletic Association (NCAA) Division I female soccer athletes from a Midwestern University. Subjects were included in the study if they were a female college-aged athlete, at least 18 years old, enrolled at a Midwestern University, on the women’s soccer team roster and participated in an offseason training program led by their team’s strength and conditioning staff.

PROCEDURES Athletic Performance Testing Athletic performance testing for lower extremity dynamic balance and hip strength was completed as part of a standard battery of tests for this cohort on two separate occasions, roughly two months apart, at the initiation and conclusion of an eight-week offseason conditioning program. Athletes were required to receive prior medical clearance from an authorized healthcare provider in order to participate. Athlete health and injury status were monitored throughout the duration of training by the team’s athletic trainer, with participation in the training program modified if needed. Initial and post-testing order was consistently applied within the testing battery (Table 1).

Table 1. Testing Procedures

Performance testing sessions occurred at the same general time of day in order to minimize diurnal variance in lower extremity dynamic balance performance,31 on a hardwood athletic court surface.

Athletes began testing with a five minute warm-up on an upright, stationary exercise bike at a Borg’s Rating of Perceived Exertion level of 13-15 (somewhat hard – hard).32 During the warm-up, demographic data including age, playing position, limb dominance (defined as the limb used to kick a soccer ball), and educational year was collected.

Star Excursion Balance Test The SEBT protocol began with lower limb length (cm) measurement in supine with a cloth measuring tape, from the inferior aspect of the anterior superior iliac spine of the pelvis to the ipsilateral distal medial malleolus. The SEBT was constructed of three tape measures secured to the floor. The apex was defined as the anterior reach direction, while the two other tape measures (posteromedial and posterolateral reach directions) were secured 135° to the apex. The athlete then performed four SEBT warm-up33 and three test trials for each limb in the anterior, posteromedial, and posterolateral directions while standing barefoot. Athletes performed test trials once their warm-up repetitions were completed, with trials named to stance limb and reach direction. The athlete stood on one limb with the great toe at the apex of the three reach directions (stance limb). The athlete’s reach limb was positioned in non-weightbearing adjacent to the stance limb, then given instructions to maximally reach in the pre-determined direction. The examiner determined the maximal reach distance by reading the point on the tape measure reached by the athlete’s great toe. Testing order remained constant, which included the right anterior, left anterior, right posteromedial, left posteromedial, right posterolateral, and left posterolateral reach directions, respectively.

During the warm-up repetitions, athletes were instructed to maintain their hands on their pelvis, and heel of the stance foot in contact with the floor throughout the test. A demonstration was provided by the examiner prior to any practice trials, in addition to verbal descriptions of criteria for an unsuccessful trial as needed, which included losing

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Figure 1. Isometric strength testing of hip abduction

balance, moving or lifting of the stance foot, shifting weight to the reach foot, or removing the hands from the pelvis. A test trial was repeated if any criteria for an unsuccessful trial were observed.

Measurements of reach distance were normalized34 to the corresponding stance limb. An average of the three test trials was used to calculate the reach distance outcome for each limb and direction. The averaged reach distances, normalized to ipsilateral stance limb length, across all three directions was used to attain a composite lower extremity balance score.9 Hip Strength Isometric hip strength was assessed at both pre- and post-testing sessions with a handheld dynamometer (HHD) (microFET2, Hoggan Scientific, LLC. Salt Lake City, UT, USA). Hip ABD and ER strength were tested as previously described with slight modifications.6 One warm-up repetition was performed prior to the test trials. The order of testing included

three trials of right hip ABD, left hip ABD, right hip ER, and left hip ER. Athletes were allowed to rest approximately five seconds between each test trial, and 20 seconds between limbs. Each trial was performed as a “make” test.

Athletes assumed the sidelying position for assessment of isometric hip ABD strength, with a strap securing the athlete’s pelvis (iliac crest) to a treatment table, while another strap was placed 10 cm proximal to the lateral femoral condyle and secured to the table with the hip in neutral position (Figure 1). The non-test limb was placed in a “position of comfort” during testing, or roughly neutral position.

The HHD was placed under the thigh strap on the superior limb, and the athlete was instructed to exert maximal force into the HHD for five seconds. Athletes were placed in short sitting with hips and knees flexed 90°, with feet non-weightbearing for isometric hip ER strength assessment (Figure 2). A strap was placed around the distal thighs to secure the hips in neutral rotation. The HHD was positioned just

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Figure 2. Isometric strength testing of hip external rotation

proximal to the medial malleolus, with instructions to push with maximal effort into the HHD for five seconds against manual resistance. Three test trials were recorded for both limbs in each direction, and averaged for data analysis, consistent with methods from a prior study.6 Examiners A physical therapist with four years of orthopedic and sports physical therapy experience led the testing procedures and provided in-person education and demonstration of testing procedures to the other examiners prior to initial testing. A physical therapy student examiner was assigned to each testing station, for both initial and post-testing. Standard error of measurement (SEM) was calculated using standard deviation (SD) and re-test correlation (r) values, where SEM = SD â&#x2C6;&#x161;1-r2. Reliability testing of the examiners revealed good-excellent test-retest reliability for leg length (r > 0.99, p < 0.0001, SEM 0.98 cm), SEBT assessment (r = 0.87, SEM 0.55 - 4.1 cm), and isometric hip strength (r = 0.88, p = 0.0006,

SEM 5.62 kg for ABD and r = 0.87, p = 0.001, SEM 1.81 kg for ER).

Strength and Conditioning Program Athletes completed an eight-week strength and conditioning program during this timeframe, consisting of two, four-week training blocks (Table 2). During this timeframe, athletes also participated in technical skills training with their coaches in individual and small group-based formats (Table 3). The strength program emphasized multi-joint exercises, trunk and lower body exercises, as well as power exercises at a frequency of 2-3 times per week. After the eight weeks of training, athletes were given one week to rest and recover from training. The athletes completed post-testing the following week.

STATISTICAL METHODS Analyses were conducted using SAS 9.4 (SAS Institute, Cary, NC) and include descriptive statistics and Pearson correlations. Dependent ANOVAs were used to test the pre-post differences after observing relative symmetry in the score distributions.

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Table 2. Strength and Conditioning Program Exercises & Training Load

Table 3. Training Program Overview*

RESULTS Seventeen athletes were included in data analysis (age: 18.8 Âą 0.9 years, height: 1.7 Âą .06 m, mass: 68.0 Âą 8.2 kg). SEBT performance and hip strength pre- and posttesting results, along with effect sizes, are outlined in Table 4. The mean values for improvement and standard deviation of these measures are reported in Table 4, along with 95% CI. Significant differences were determined based on the 95% CI value not containing a zero

value, thus rejecting the null hypothesis of improvements being due to chance alone. SEBT performance improved globally from pre- to post-testing; however, varied findings were observed with respect to limb dominance and reach direction. Significant improvements were identified in SEBT composite reach score in the dominant (DOM) and nondominant (NDOM) limbs. Significant improvements were seen in the anterior and posterolateral reach directions; however, this

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Table 4. Pre- and Post-Testing Results for Star Excursion Balance Test Performance and Isometric Hip Strength after Training

was not observed for the posteromedial direction. Effect size magnitude order was consistent across DOM and NDOM limbs for SEBT composite score and individual reach directions, with the anterior reach direction demonstrating a small-moderate effect size (0.40 – 0.66).

Athletes demonstrated a significant improvement in isometric hip ER strength, but this trend was not observed for hip ABD. Large effect sizes were observed for DOM and NDOM hip ER strength

gains (0.87 – 1.0). Further, DOM hip ER strength gains were significantly associated with DOM anterior reach performance improvements (r2 =0.37, p<0.01), as described in Table 5. Thus, DOM hip ER strength increases explained 37% of the variance in DOM anterior reach performance gains.

DISCUSSION Rehabilitation professionals are often faced with the challenge of designing and implementing training

Table 5. Pearson Correlations for Changes in Star Excursion Balance Test* (SEBT) Composite (COMP) Score and Anterior (ANT) Reach Performance, and Hip Abduction (ABD) and External Rotation (ER) Strength† for the Dominant (DOM) and Nondominant (NDOM) Limbs

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programs that will achieve desired outcomes in a safe, efficient manner. Little evidence exists regarding a multi-faceted team-based training programâ&#x20AC;&#x2122;s influence on lower extremity injury risk factor modification. This is one of the first investigations to examine training adaptations for hip strength and lower extremity dynamic balance in high-level female soccer athletes.

Various exercise protocols targeting the proximal and distal lower limb have been examined with respect to their associated influence on injury risk factors. Stearns and Powers25 investigated changes in hip muscle performance after a four-week plyometric and balance exercise program in recreationally active females, which resulted in improved hip strength and drop-jump landing mechanics. However, several ankle strengthening protocols have not shown improvement in lower extremity dynamic balance in those with chronic ankle instability.35 The improvements in hip ER strength and lower extremity dynamic balance in the current cohort were observed after completing a broad training regimen over an eight-week timeframe. Conversely, a similar degree of improvement was not observed for the SEBT posteromedial reach direction. This could in part be due to the lack of significant change in hip ABD strength in this cohort, as gluteus medius EMG activation has previously been shown to be greatest when performing the SEBT posteromedial reach.36 Improving SEBT anterior reach performance is of particular interest, as this has shown to be the reach direction with best ability to predict lower extremity injury in athletes.7 The current study identified DOM hip ER strength gains being significantly associated with improved DOM anterior reach distance after training. Other investigations have similarly identified an association between hip strength and anterior reach performance in collegiate female athletes;22 however, it was hip flexor and extensor strength that was fairly correlated, rather than hip ER strength. Hip flexor and extensor strength were not assessed in the current study, which may have offered further insight into training adaptations.

Additionally, a hip strengthening-focused program was superior to traditional rehabilitation for improving anterior reach performance symmetry in those recovering from ACL-reconstruction.30 The current

training program included a multi-modal approach with core stability, hip strengthening, multi-joint, and power exercises. Similar exercises have been applied in previous investigations, resulting in improved lower extremity dynamic balance performance19 and a reduced number of ACL injuries.26,27 Findings in the current and previous studies support the notion that multi-faceted training programs can positively effect SEBT anterior reach performance and hip strength.

Pre-test SEBT performance values were similar to those found in a previous examination of Division I female soccer athletes for the composite and anterior reach directions; however, post-test values were somewhat increased, comparatively,9 with mostly moderate-large effect sizes observed in lower extremity balance improvements. When reporting values for SEBT distances, it is important to consider the method used to calculate reach performance. Some studies report a single normalized maximal reach value in each direction,7,37-39 which is then used to calculate a composite reach distance on each limb, while another computed the average of three test trials to attain normative data.9 This discrepancy in statistical methodology can have a profound impact on the interpretation of study outcomes. Generally, using average values for reach distances will decrease the athleteâ&#x20AC;&#x2122;s overall SEBT performance.

When applying injury risk stratification, historically maximal reach distance scores in each direction have been reported.7,37 The current study reported average reach distances observed in each direction across three test trials for comparison to a similar population in a previous study.9 Standardized reporting of SEBT outcomes would improve generalizability across athlete groups.

SEBT performance relies in part on varying hip and thigh muscle activation patterns according to reach direcction.36,40 Gluteus medius and maximus activation during the SEBT have been investigated with EMG analysis.36 The gluteus medius is thought to contribute to hip ER strength, but primarily with the hip positioned in extension. Since the hip joint on the stance limb is positioned in flexion for the vast majority of the SEBT anterior reach, it is difficult to speculate if improved strength in this muscle group contributed to improved SEBT performance. The

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primary hip ER muscle group includes the piriformis, superior/inferior gamellus, obturator internus/ externus, and quadratus femoris. These muscles are difficult to assess with EMG analysis due to their location and anatomical complexity. Future investigations into other muscle activation strategies on the SEBT may provide further insight for rehabilitation professionals to improve training program design and SEBT performance.

Comparisons of isometric hip strength testing methodology to the specificity of SEBT performance, along with the outcomes in other athletic populations must be examined. Hip ER strength performance in this group of high-level soccer athletes was similar to previous investigations examining athletes in other sports. Differences in study populations and testing protocols may account for some variances. Soccer athletes heavily use their lower extremities given the nature of their sport requiring running, cutting, jumping, and kicking activities. However, the mean hip ER strength values were slightly lower compared to basketball and track athletes.23 Hip strength outcomes may have been influenced by testing position. Hip ER was tested with the athlete seated in 90° of hip flexion, similar to previous investigations.6,21,22 During the SEBT, athletes rarely approach this degree of hip flexion. It would seem appropriate to explore other joint angles of isometric hip strength assessment, as it was previously reported that approximately 35° of hip flexion occurs when performing the SEBT in healthy female controls.13 Similarly, hip ABD was assessed in a neutral position in the current study, while testing position of slight hip ABD has been applied previously.6,23 It was found that isokinetic concentric hip extensor and flexor strength was not highly associated with SEBT performance in college female soccer athletes.18 Considerations for differences between athletic populations and hip strength testing methods limit generalizability to a degree.

After eight weeks of training, measurements of risk factors for lower extremity injury significantly improved in this cohort. Hip ER strength and SEBT anterior reach improved bilaterally after training; however, only DOM hip ER strength gains were significantly associated with increases in DOM anterior reach. Previously, an association between hip ER

strength and SEBT performance was only observed in the posteromedial reach direction in a cohort of high school-aged female lacrosse athletes.21 Differences in sport-specific requirements and athletic population may have partially accounted for these variances. Specifically, soccer athletes’ balance performance was greater when standing on the NDOM extremity during both static41 and dynamic42 activities when compared to the DOM limb. The DOM limb is typically defined by the side preferred for kicking, which leaves the NDOM, or stance limb, favored to provide dynamic stability during this activity. The authors posit that the DOM extremity had a greater potential for strength gains given lower pre-test values, which was reflected by a small, but larger increase in DOM hip ER strength when compared to the NDOM limb. The greater magnitude of DOM hip ER strength improvement may have led to a higher degree of association with DOM SEBT anterior reach performance gains. Also, the intent of the current investigation was to identify an association between hip strength and SEBT anterior reach performance training adaptations, rather than baseline performance correlations. A ceiling effect may have influenced outcomes for hip strength and SEBT performance gains, given a fit, healthy cohort of high level soccer athletes was studied. Different levels of trainability may exist in other athlete or clinical populations.

LIMITATIONS The ability to generalize this report is limited in several ways. The athletes were simultaneously participating in individual and small group-based technical training with their soccer coaching staff twice per week while completing the strength and conditioning program, which makes it difficult to discern which part of the training program had the most influence on testing results. Other limitations in methodology included the lack of a control group and small sample size, given the nature of this retrospective report.

The lack of blinding is also a potential source of bias.

Allowing for a “rest” week between the cessation of the strength training program and post-test may have influenced outcomes to a degree, as fatigue level was not formally assessed amongst the athletes at the time of post-testing. Although injury risk factor markers did improve with training, it is inappropriate to

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speculate whether a change in injury rates would be observed given the scope of this study. The overall improvement in lower extremity balance and hip strength is difficult to interpret without substantial minimal clinically important difference or minimal detectable change data available for this population. Future research may work to identify clinically meaningful change in SEBT performance according to various athlete groups.

8.

9.

10.

CONCLUSION Isometric hip ER strength and lower extremity dynamic balance as measured by the SEBT, with the exception of the posteromedial reach direction, improved after completing an eight-week strength and conditioning program in collegiate, Division I female soccer athletes. DOM hip ER strength gains appear to be associated with improved SEBT anterior reach on the ipsilateral limb. Future investigations should prospectively investigate lower extremity injury risk factors and intervention strategies in female soccer players.

11.

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Nakagawa L, Hoffman M. Performance in static, dynamic, and clinical tests of postural control in individuals with recurrent ankle sprains. J Sport Rehabil. 2004;13(3):255-268.

Herrington L, Hatcher J, Hatcher A, et al. A comparison of Star Excursion Balance Test reach distances between ACL deficient patients and asymptomatic controls. Knee. 2009;16(2): 149-152.

Olmsted LC, Carcia CR, Hertel J, et al. Efficacy of the Star Excursion Balance Tests in detecting reach deficits in subjects with chronic ankle instability. J Athl Train. 2002;37(4):501-506.

Delahunt E, Chawke M, Kelleher J, et al. Lower limb kinematics and dynamic postural stability in anterior cruciate ligament-reconstructed female athletes. J Athl Train. 2013;48(2):172-185.

Aminaka N, Gribble PA. Patellar taping, patellofemoral pain syndrome, lower extremity kinematics, and dynamic postural control. J Athl Train. 2008;43(1):21-28.

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Filipa A, Byrnes R, Paterno MV, et al. Neuromuscular training improves performance on the star excursion balance test in young female athletes. J Orthop Sports Phys Ther. 2010;40(9):551-558.

Hoch MC, Staton GS, McKeon PO. Dorsiflexion range of motion significantly influences dynamic balance.

J Sci Med Sport. 2011;14(1):90-92.

Gordon AT, Ambegaonkar JP, Caswell SV. Relationships between core strength, hip external rotator muscle strength, and star excursion balance

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test performance in female lacrosse players. Int J Sports Phys Ther. 2013;8(2):97-104.

22. Ambegaonkar JP, Mettinger LM, Caswell SV, et al.

Relationships between core endurance, hip strength, and balance in collegiate female athletes. Int J Sports Phys Ther. 2014;9(5):604-616.

23. Leetun DT, Ireland ML, Willson JD, et al. Core stability measures as risk factors for lower extremity injury in athletes. Med Sci Sports Exerc.

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24. Lawrence RK, 3rd, Kernozek TW, Miller EJ, et al.

Influences of hip external rotation strength on knee mechanics during single-leg drop landings in females. Clin Biomech (Bristol, Avon). 2008;23(6):806813.

25. Stearns KM, Powers CM. Improvements in hip muscle performance result in increased use of the hip extensors and abductors during a landing task.

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26. Mandelbaum BR, Silvers HJ, Watanabe DS, et al.

Effectiveness of a neuromuscular and proprioceptive training program in preventing anterior cruciate ligament injuries in female athletes: 2-year follow-up. Am J Sports Med. 2005;33(7):1003-1010.

27. Wingfield K. Neuromuscular training to prevent knee injuries in adolescent female soccer players.

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28. Baldon Rde M, Serrao FV, Scattone Silva R, et al.

Effects of functional stabilization training on pain, function, and lower extremity biomechanics in women with patellofemoral pain: a randomized clinical trial. J Orthop Sports Phys Ther.

2014;44(4):240-a248.

29. Dolak KL, Silkman C, Medina McKeon J, et al. Hip strengthening prior to functional exercises reduces pain sooner than quadriceps strengthening in females with patellofemoral pain syndrome: a randomized clinical trial. J Orthop Sports Phys Ther.

2011;41(8):560-570.

30. Garrison JC, Bothwell J, Cohen K, et al. Effects of hip strengthening on early outcomes following anterior cruciate ligament reconstruction. Int J Sports Phys Ther. 2014;9(2):157-167.

31. Jorgensen MG, Rathleff MS, Laessoe U, et al. Timeof-day influences postural balance in older adults.

Gait Posture. 2012;35(4):653-657.

32. Borg G. Borg’s perceived exertion and pain scales.

Champaign, IL: Human Kinetics; 1998.

33. Robinson RH, Gribble PA. Support for a reduction in the number of trials needed for the star excursion balance test. Arch Phys Med Rehabil. 2008;89(2):364370.

34. Gribble PA, Hertel J. Considerations for normalizing measures of the star excursion balance test. Meas Phys Educ Exerc Sci. 2003;7(2):89-100.

35. Hall EA, Docherty CL, Simon J, et al. Strengthtraining protocols to improve deficits in participants with chronic ankle instability: a randomized controlled trial. J Athl Train. 2015;50(1):36-44.

36. Norris B, Trudelle-Jackson E. Hip- and thigh-muscle activation during the star excursion balance test. J Sport Rehabil. 2011;20(4):428-441.

37. Butler RJ, Lehr ME, Fink ML, et al. Dynamic balance performance and noncontact lower extremity injury in college football players: an initial study. Sports Health. 2013;5(5):417-422.

38. Chimera NJ, Smith CA, Warren M. Injury history, sex, and performance on the functional movement screen and Y balance test. J Athl Train.

2015;50(5):475-485.

39. Coughlan GF, Fullam K, Delahunt E, et al. A comparison between performance on selected directions of the star excursion balance test and the Y balance test. J Athl Train. 2012;47(4):366-371.

40. Earl JE, Hertel J. Lower-extremity muscle activation during the star excursion balance tests. J Sport Rehabil. 2001;10:93-104.

41. Barone R, Macaluso F, Traina M, et al. Soccer players have a better standing balance in nondominant one-legged stance. Open Access J Sports Med. 2010;2:16.

42. Fletcher IM, Long CS. The effects of kicking leg preference on balance ability in elite soccer players.

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IJSPT

ORIGINAL RESEARCH

IMPROVEMENTS IN KNEE EXTENSION STRENGTH ARE ASSOCIATED WITH IMPROVEMENTS IN SELF-REPORTED HIP FUNCTION FOLLOWING ARTHROSCOPY FOR FEMOROACETABULAR IMPINGEMENT SYNDROME Chelseana C. Davis, PT, SCS1 Thomas J. Ellis, MD2 Ajit K. Amesur, BS3 Timothy E. Hewett, PhD, FACSM3,4,5 Stephanie Di Stasi, PT, PhD, OCS1,4,5

ABSTRACT Background: Recovery of strength is critical for return to sport, and is a known predictor of functional outcomes in post-surgical orthopedic populations. Muscle weakness is a known impairment in patients with femoroacetabular impingement syndrome (FAIS) but whether improvements in muscle strength after arthroscopy are associated with improved hip function is unknown.

Hypothesis/Purpose: To examine the relationships between changes in hip and thigh muscle strength and self-reported function in athletes undergoing arthroscopy for FAIS. Study Design: Single cohort descriptive and correlational study Methods: Twenty-eight athletes underwent strength testing and completed the Hip Outcome Score Activities of Daily Living (HOS-ADL) and Sports (HOS-S) subscales prior to and six months after surgery. Isokinetic knee extension and flexion strength were measured using a Biodex dynamometer at 60°/s and 300°/s. Isometric hip abduction strength was measured using a custom dynamometer. Changes in strength, limb symmetry, and HOS scores were assessed using paired t-tests. Spearman’s rank correlations were used to examine relationships between change in involved limb strength and change in HOS scores.

Results: Subjects were tested an average of 32 days before and 178 days after surgery. HOS-ADL and HOS-S subscales improved by a mean of 19.0 ±21.1 and 23.8±31.9, respectively, over time (p<0.001). Hip abduction strength did not increase over time in either limb (p≥0.27). Involved limb knee flexion and extension strength did not increase significantly over time (p-values: 0.10-0.48) with the exception of knee extension at 300°/s (p=0.04). Uninvolved limb knee extension strength at both velocities and knee flexion strength at 60°/s improved significantly over time (p<0.012). Increases in knee extension strength (60°/s) of the involved limb were significantly correlated with improvements on the HOS-ADL (r=0.431; 0=0.025) and HOS-S (r=0.439; p=0.025). There were no significant relationships between changes in involved limb hip abduction or knee flexion strength and HOS subscales (p≥0.123).

Conclusion: Improvements in knee extension strength were associated with improvements in self-reported hip function in athletes following arthroscopy for FAIS. Individuals with knee extension strength deficits prior to surgery may benefit from targeted knee extension strengthening during post-operative rehabilitation to improve functional outcomes.

Level of Evidence: Level III (non-randomized controlled cohort study) Key Words: femoroacetabular impingement syndrome, hip strength, knee strength

1

The Ohio State University Wexner Medical Center Sports Medicine, Columbus, OH, USA 2 Trauma and Total Joint Reconstruction, Orthopaedic One, Columbus, OH, USA 3 Sports Medicine Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, USA 4 Department of Orthopaedics, The Ohio State University, Columbus, OH, USA 5 Departments of Orthopaedic Surgery, Physical Medicine & Rehabilitation, Physiology and Biomedical Engineering, Mayo Clinic, Minneapolis and Rochester, MN, USA Acknowledgements This study was funded in part by the Sports Physical Therapy Section of the American Physical Therapy Association

CORRESPONDING AUTHOR Chelseana C. Davis, PT, SCS 6515 Pullman Dr. Suite 2100 Lewis Center, OH 43085 Phone: 614-542-9335 Email: chelseana.davis@osumc.edu

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INTRODUCTION Femoroacetabular impingement (FAI) is increasingly identified as a significant cause of hip pain and disability in athletes due to advances in medical imaging and knowledge of structural hip pathologies.1,2 FAI is characterized as an abnormal bony morphology of the femoral head-neck junction (cam deformity), the acetabulum (pincer deformity), or both (combined cam and pincer deformity), which commonly develops during adolescence3,4 and can result in the premature development of hip osteoarthritis.4-6 Surgical resection of the bony lesion is commonly performed using arthroscopic techniques after failure of non-operative management, and can result in favorable outcomes for the majority of affected athletic individuals.2,5 Importantly, some athletes do not return to their previous level of function following arthroscopy, and efforts to identify modifiable impairments related to functional limitations are critical to maximizing positive outcomes.

Individuals with FAI syndrome (FAIS) (i.e. those with pain and functional limitations associated with FAI morphology) commonly demonstrate hip muscle weakness7,8 and altered kinematics of the involved hip during functional and sporting activities.9,10 Compared to uninjured controls, subjects with FAIS demonstrate deficits in hip flexion, abduction, external rotation, and adduction strength.8 Furthermore, hip weakness and muscle performance deficits are hypothesized to contribute to altered kinematics, including increased hip adduction and internal rotation, during dynamic single leg tasks in subjects with FAIS.9,10 Casartelli et al.7 found that at 2.5 years after hip arthroscopy, maximal voluntary contraction for all hip muscle groups had returned with the exception of hip flexion strength in a small cohort of patients. Although these results are favorable at two and a half years post-operatively, return to sport for an athletic population following hip arthroscopy may occur as early as six months post-operatively.11-14 Thigh muscle weakness, including the knee flexors and extensors, may also be a critical factor in the recovery of function in patients with FAIS. Quadriceps femoris strength is a known predictor of functional outcomes in other post-surgical orthopedic populations including anterior cruciate liga-

ment reconstruction15 and total hip replacement.16 Due to their role as major force producers in the lower extremity for both daily and sporting activities, deficits in thigh muscle strength may have a significant impact on function following hip arthroscopy. Importantly, adequate thigh muscle strength is highly relevant for athletes attempting to return to cutting, pivoting, and jumping sports.

Muscle strength symmetry is a common criterion for injured athletes to achieve prior to returning to sports because of its association with improved function,17 more symmetrical biomechanics,18,19 and lower re-injury risk.20 However, this hypothesis has not been validated in patients with FAIS, despite the fact that muscle weakness is characteristic of this painful syndrome. The relationship between muscle weakness and self-reported function in the shortterm (i.e. within the first six months of surgery and during the course of supervised rehabilitation) needs to be quantified in order to help develop the most effective post-operative rehabilitation program. The purpose of this study was to examine the relationship between changes in hip and thigh muscle strength and changes in self-reported function in athletes with FAIS before and six months after hip arthroscopy. The primary hypothesis was that increases in hip abduction, knee extension, and knee flexion strength of the involved limb after surgery would be positively associated with improvements on the Hip Outcome Score (HOS) Activities of Daily Living (HOS-ADL) and Sports (HOS-S) subscales. The second hypothesis was that involved limb weakness in hip abduction and knee extension and flexion compared to the uninvolved limb prior to surgery would be resolved at the 6-month post-operative follow-up.

METHODS Participants Athletes who were undergoing hip arthroscopy for FAIS were recruited from a single orthopedic practice from April 2012 to December 2013. Athletes between the ages of 14 and 50 were eligible if they were diagnosed with FAIS per radiographic findings and clinical examination, and were regular participants in cutting, jumping, pivoting, or lateral movement activities for at least 50 hours per year prior to the onset of hip symptoms.21 Radiographic guidelines for

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FAIS included: alpha angle > 50° for cam impingement or presence of acetabular retroversion and/or coxa profunda for pincer impingement and minimal degenerative hip changes (Tönnis grade > 1). Potential subjects were excluded if they: (1) were diagnosed with osteopenia or osteoporosis, (2) were diagnosed with moderate to advanced osteoarthritis at the time of the procedure (Tönnis grade > 1 on radiographic examination), or (3) had a history of lumbar spine or lower extremity surgery (e.g. laminectomy or knee ligament reconstruction) or injury that required a period of immobilization or non-weight-bearing.

Criteria for study inclusion were reviewed by the patient’s orthopaedic surgeon (TE) and a licensed physical therapist (SD) prior to enrollment. A total of 42 subjects were recruited and informed consent was obtained from all participants in this study, in accordance with the study protocol, as approved by the The Ohio State University Institutional Review Board.

Surgical Procedures and Rehabilitation Program All hip arthroscopies were performed by a board-certified orthopedic surgeon and included femoral and/or acetabular osteoplasty and/or labral repair. A standardized post-hip arthroscopy physical therapy guideline was used in The Ohio State University Wexner Medical Center (OSUWMC) Sports Medicine Physical Therapy clinics. These physical therapy guidelines were provided to patients undergoing rehabilitation at non-OSUWMC facilities to give to their physical therapist. The clinical guideline used for the current study was developed based on current literature22-26 and is consistent with the clinical practice guideline for non-arthritic hip pain.27 The rehabilitation guideline consists of four phases with subjective and objective criteria to progress through the phases. Initially, progression is limited by tissue healing and is later focused on subjective reports of pain and performance of objective tests that address strength and limb symmetry.

Testing Procedures Self-reported outcomes and strength data were collected prior to surgery and six months post-operatively.

Self-Reported Outcome Measures Subjects were asked to complete the Hip Outcome Score Activities of Daily Living (HOS-ADL) and

Sports (HOS-S) subscales. The HOS-ADL subscale contains 19 items (17 scored) pertaining to basic daily activities, and the HOS-S subscale contains 9 scored items pertaining to higher-level athletic activities.28 Each question is activity-based, and ranges from a score of 0 (unable to do) to 4 (no difficulty). Higher scores (maximum of 100%) on both subscales represent better function. The HOS is valid,28 reliable,29,30 and responsive to change30,31 in this population. HOSADL and HOS-S outcome measures were completed pre-operatively and 6 months post-operatively.

Assessment of Knee Extension and Flexion Strength Isokinetic strength testing was used to assess the concentric strength of the knee extensor and knee flexor muscle groups of both limbs by a single physical therapist. Subjects were seated upright on an isokinetic dynamometer (Biodex System 3, Biodex Medical Systems, Inc, Shirley, NY) with their hips and knees flexed to 90°. Chair depth, height, placement, and length of attachment arm were adjusted for each subject and recorded for consistency between test sessions. Subjects were secured with straps at the distal shank, mid-thigh, pelvis, and trunk. All tests were performed on the uninvolved lower extremity first and range of motion was set from 100° to 10° of knee flexion. Two sets of five repetitions were performed at 60°/second and then two sets of ten repetitions were performed at 300°/ second with 90-second rest breaks between tests.

Subjects were instructed to “kick and pull through the whole range of motion as fast and hard as you can,” and then given two practice repetitions prior to each test set to ensure comfort with the task and proper strap fixation. Standardized verbal encouragement was provided to elicit maximal effort from each subject. Similar methods of assessing isokinetic thigh strength have been shown to be highly reliable (ICCs 0.82-0.91) and valid.32 Peak flexion and extension torque values (ft-lbs) were recorded for all testing sets; the peak torque value from both sets for each muscle group was normalized to body weight in pounds and used in the analyses. Limb symmetry index (LSI) values were calculated with the peak normalized torque value of the involved limb divided by the peak normalized torque value of the uninvolved limb and multiplied by 100.

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Assessment of Hip Abduction Strength Isometric hip abduction strength was assessed using a custom dynamometer with a strain gauge. All hip strength measurements were collected by the same licensed physical therapist (SD). Hip abduction strength was tested in the side-lying position with the subject’s head, scapula, buttocks, and heels against the wall (Figure 1). The straps of the custom dynamometer were then placed just proximal to the femoral condyles. Prior to testing, subjects were instructed to place their hand lightly on the table for balance, while the examiner manually secured the position of the bottom/non-testing limb to the mat.

The subject was instructed to gradually increase force over the verbal count of three then to produce a maximal voluntary contraction against the straps for five seconds. Subjects were given two practice trials and then performed two testing trials for each limb. The peak force value of the two trials was used for analyses. A regression equation based on standardized weight measurements was used to convert test output from millivolts to pounds. Data were then normalized to the subject’s body weight in pounds.

LSI was calculated as peak normalized force value of the involved limb divided by the peak normalized force value of the uninvolved limb and multiplied by 100. These testing methods have demonstrated good intra-rater reliability for the assessment of hip abduction strength in healthy controls in the OSUWMC Sports Medicine Biodynamics Laboratory (ICC [2,1]=0.875, minimal detectable change= 2.1 lb).

Data Analyses Data was analyzed with SPSS version 20 (SPSS Inc., Chicago, IL, USA). Assumptions of parametric test-

Figure 1. Hip abduction strength testing set up.

ing were assessed with histograms, scatterplots, and Shapiro-Wilk tests. Spearman’s rank correlation coefficients were calculated to quantify the relationships between the change scores in normalized hip and thigh strength and HOS subscales. Paired t-tests were used to assess change in involved and uninvolved limb strength, limb symmetry, and self-reported measures over time. Frequency counts were used to describe the number of subjects who demonstrated clinically significant weakness before and after surgery, and how many underwent a clinically significant change in strength over the same period.

Clinically significant weakness of the involved limb was operationally defined as at least a 10% deficit on the involved limb compared to the uninvolved limb.

Since recommendations on adequate strength symmetry in this population have not been defined,22,27 our operational definition of clinically significant weakness was based on return to activity strength criteria for patients who have undergone knee ligament reconstruction.33 A clinically significant change in strength was operationally defined as at least a 10% change34 from pre-operative to post-operative testing.

Statistical significance was set a priori at α=0.05.

RESULTS All of the 42 enrolled subjects completed pre-operative testing for knee extension and knee flexion strength testing. Twenty-eight of the 42 enrolled athletes returned for six-month post-operative testing and were included in the final analysis (Table 1).

Of those lost to follow-up, one elected to not have surgery, six elected to drop out of the study prior to post-operative testing, one refused to return for testing, five had contralateral hip surgery, and one had an unrelated medical condition that precluded post-operative testing. Subjects in the final sample (N=28) did not differ significantly from subjects in the initial sample (N=42) in age, sex distribution, BMI, time from pre-operative testing to surgery, or HOS subscale scores (p>0.05). Of the 28 subjects who participated in both testing sessions, three subjects did not complete either pre- or post-operative strength testing due to testing device malfunction and one subject could not complete pre-operative strength testing due to time limitations.

The HOS-ADL scores increased significantly from pre-operative to six-month post-operative assess-

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Table 1. Demographic characteristics

ments (mean ± SD; pre-operative: 68.9 ± 18.0, six-month post-operative: 88.1 ± 14.2; p < 0.001).

Similarly, the HOS-S scores significantly increased from pre-operative to six-month post-operative assessments (pre-operative: 50.82 ± 21.70; sixmonth post-operative: 74.7 ± 21.8; p < 0.001).

Muscle strength asymmetry was identified in a significant portion of subjects prior to arthroscopy. Clinically significant weakness of the involved limb (<90% LSI) was found in 27.5% of the subjects for knee extension, 22.5% for knee flexion, and 30.6% for hip abduction.

Conversely, an LSI of >110% was identified in 12.5% of subjects for knee extension, 22.5% for knee flexion, and 8.3% for hip abduction strength.

Isometric hip abduction strength did not change in either limb following hip arthroscopy (Table 2).

Uninvolved limb isokinetic knee extension strength improved significantly over time at both velocities; however, only involved limb knee extension strength at 300°/second, not 60°/second, improved significantly over time (Table 3). Bilateral isokinetic knee flexion strength did not change over time (P ≥0.48) with the exception of a significant increase in the uninvolved limb at 60°/second (Table 3).

There were no significant changes in mean LSI over time for any of the muscle groups tested (Figure 2).

Approximately one-third of subjects demonstrated no clinically meaningful change (>10% increase

Table 2. Normalized isometric hip abduction strength before and six months after hip arthroscopy

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Table 3. Thigh muscle isokinetic strength before and six months after hip arthroscopy

Figure 2. Limb symmetry indexes (%) of peak strength values for hip abduction, knee flexion, and knee extension pre- and postoperatively. No statistically significant changes (P ≥ 0.115). Bars represent standard deviation values. Abbreviations: SLR, straight leg raise; 6 mo, 6 month post-operative; abd, abduction; ext, extension; flex, flexion; s, second.

or decrease) in isometric hip abduction strength of the involved limb over the testing period; 27% demonstrated an increase and 38% showed a decrease compared to pre-operative values. For involved knee extension at 60°/second, 61% demonstrated no clinically meaningful change in strength, 32% of subjects demonstrated a clinically meaningful increase and the remaining 7% showed a clinically meaningful decrease compared to pre-operative values. Involved limb knee flexion strength at 60°/second did not demonstrate a clinically meaningful change in 61% of subjects; 25% demonstrated a clinically meaningful

increase, and 14% demonstrated a clinically meaningful decrease compared to pre-operative values.

Increases in involved limb knee extension strength at 60°/second were significantly correlated with improvements in both the HOS-ADL (r = 0.431; p = 0.025; Figure 3) and HOS-S scores (r = 0.439; p = 0.025; Figure 3). Changes in uninvolved knee extension strength at both velocities were not correlated with increases in HOS-ADL or HOS-S scores (p ≥ 0.253; Figures 3 and 4). There were no statistically significant relationships between changes in hip abduction

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Figure 3. Change in Normalized Knee Extension Strength at 60 deg/s and HOS-ADL and HOS-S over Time. Torque measured in ft-lbs and normalized to subject weight (lbs). Abbreviations: deg, degrees; s, second.

Figure 4. Change in Normalized Knee Extension Strength at 300 deg/s and HOS-ADL and HOS-S over Time. Torque measured in ft-lbs and normalized to subject weight (lbs). Abbreviations: deg, degrees; s, second.

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and knee flexion strength in either limb with changes in HOS-ADL (p ≥ 0.139) or HOS-S (p ≥ 0.123) scores.

DISCUSSION In the present study, the relationships between changes in hip abduction, thigh muscle strength, and self-reported hip function in athletes with FAIS were evaluated before and after hip arthroscopy. The findings partially supported the a priori hypothesis that strength gains in the involved limb would be associated with increases in both ADL and sports-related self-reported hip function. Only mean involved limb knee extension strength at 300°/second improved over time this was not associated with improvements in self-reported hip function. Despite a lack of significant improvement in the group mean knee extension strength at 60°/second, there was a positive association between improvements in low velocity knee extension strength and self-reported hip function. This relationship has not been previously identified in patients with FAIS, and adds important knowledge to the current understanding of muscle function impairments in athletes with FAIS. Weakness of hip musculature is commonly identified in individuals with painful, non-arthritic hip pathology.7,8,31 In this study, mean hip abduction strength did not improve following hip arthroscopy and improvements in hip abduction strength were not associated with improvements in self-reported hip function. In a recent small case control study, individuals with FAIS demonstrated long-term improvements in hip abduction strength and post-operative strength values comparable to healthy individuals.7 Hip abduction strengthening is a major focus during early phases of rehabilitation (in order to improve gait mechanics) as well as late phase rehabilitation to normalize lumbo-pelvic and lower extremity control with higher level functional activities.25,26 The subjects in this study did not demonstrate the expected hip abduction strength gains of the involved limb following arthroscopy and rehabilitation. This may be due in part to the short-term follow-up time of this study (six months post-operative) as compared to the two and a half years post-operative follow-up in the study by Casartelli et al.7 Furthermore, the lack of controls in this study make it impossible to determine whether bilateral strength impairments,

which are common to individuals with chronic hip joint pain,36 were characteristic of this sample.

Future work should investigate the time course of recovery of normal, symmetrical muscle strength in individuals with FAIS. Assessment of thigh muscle weakness in patients with hip pathology has previously been limited to older adults with hip osteoarthritis.16,35 Quadriceps femoris weakness was associated with greater functional disability in a case-control study of individuals with mild to moderate hip osteoarthritis35 and also predicted poorer post-operative function in a small prospective cohort early after total hip arthroplasty.16 The current findings show that improvements in knee extension strength, but not knee flexion strength, are also related to improvements in self-reported hip function in young, athletic individuals with FAIS. Improvements in normalized muscle strength were expected following arthroscopy due in part to post-operative physical therapy that included lower extremity strengthening. However, the only significant improvements in involved limb strength was in mean knee extension strength at 300°/second. Late stage rehabilitation, which includes plyometric exercises to prepare for return to sport, may explain the changes in high-velocity force production of the knee extensors. In contrast, improvements in low velocity knee extension strength likely requires isolated, high load quadriceps strengthening; this is not currently included in the standard clinical guidelines used in this study. Importantly, evaluation of individual strength data at both velocities revealed significant variability in muscle performance improvements; only one-third of subjects demonstrated significant gains in knee extension strength at 60°/second. Though this subgroup was not significantly weaker than the rest of the group prior to surgery, their improvements in knee extension strength over the study period corresponded with an average improvement of 32.5 points on the HOS-ADL score as compared to their counterparts, who improved an average of 12.2 points. Though the influence of quadriceps muscle weakness on function cannot be determined from this study, the positive association between improved quadriceps strength and hip function indicate that evaluation and targeted treatment of quadriceps weakness could be beneficial for patients undergoing hip arthroscopy for FAIS.

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Over half of the cohort demonstrated no clinically significant change in knee flexion strength in the involved limb, while one-quarter showed an improvement in strength, and the remaining subjects showed a decline in strength. In sum, these data indicate that longer-term follow-up, comparison to a healthy control group, and method of strength testing are important to fully understanding the strength impairments of this population. These results also indicate that it may take longer than six months for athletes to regain functional strength for hip and thigh musculature at a time that is pivotal for return to sport.

Limb symmetry index (LSI) is a useful calculation to assess post-operative outcomes and is widely utilized as one component of return to sport criteria in other orthopedic populations.20 The mean LSI for knee extension, flexion, and hip abduction strength in this cohort demonstrated no clinically meaningful (<90%) deficits prior to or following arthroscopy. There were also no significant changes in LSI over the testing period for any of the muscle groups tested despite significant improvements in uninvolved limb strength for knee extension and knee flexion. These findings may be explained by the bilateral muscle weakness that is common to this clinical population.7,36 In a group of young adults with chronic hip joint pain, weakness of the hip rotators and abductors was identified in both the involved and uninvolved hips.36 In sum, these data indicate that LSI alone may not be adequate to capture the muscle strength impairments in both limbs in this population. Bilateral pre-operative weakness may be a result of reduced activity levels for a prolonged period following the onset of symptoms and prior to diagnosis and surgical treatment for FAIS. While LSI is one important marker of effective rehabilitation and muscle recovery, limb-specific changes may be most relevant to the recovery of function in this population.

Current practice guidelines for the post-operative treatment of non-arthritic hip pain are limited to expert opinion.22,27 Hip arthroscopy improves function in the majority of carefully selected patients5,12,13,37 but some athletes do not successfully return to their previous level of activity.5,12,37 The goal of this study was to determine whether increases in hip abduction and

knee extension and flexion muscle strength would be associated with improvements in self-reported function in a cohort of athletes following hip arthroscopy for FAIS. These data indicate a positive association between involved limb knee extension strength and hip function in athletes following arthroscopy for FAIS. Though the causal link between increased knee extension strength and better hip function cannot be determined from the current study, future studies should examine the effect of progressive strengthening, including exercises targeted at quadriceps weakness, on return to activity outcomes in this population.

There are several limitations to the current study.

This study was a secondary analysis of a larger observational study evaluating biomechanics in individuals with FAIS and was therefore not powered to detect changes in muscle strength. The subject attrition rate of 30% was not anticipated, and the second arthroscopy rate was high in this sample (12%).

While demographic data were not different between the initial and final sample population, attrition may have influenced the findings of this study. Assessing only hip abduction strength was a significant weakness of this study. The custom hip strength dynamometer used in this study was part of a larger observational study evaluating biomechanics in individuals with a variety of lower extremity conditions and its design did not allow inter-limb strength testing of other muscle groups; thus it cannot be determined from this study whether improvements in strength of other hip muscle groups may be more strongly related to improvements in self-reported hip function. Different isokinetic testing speeds or the use of isometric knee extension/flexion testing may have yielded different results; however, the use of both low and high velocity assessments is consistent with clinical practice at OSUWMC for patients with hip pain. Pain during hip and thigh muscle testing also occurred in some individuals that may have adversely impacted their torque output. The lack of an uninjured control group limits the ability to identify bilateral muscle weakness, which has recently been identified in patients with chronic non-arthritic hip pain.36 Although relevant to return to activity timeframes, the short-term follow-up in this small cohort further limits the generalizability of these data. Finally, adherence to the clinical guideline by the physical therapists providing care

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to these subjects and subject compliance to the rehabilitation program were not documented as they were not the focus of the current study. Both could have impacted patient-reported hip function and strength testing results.

CONCLUSION Improvements in knee extension strength at 60°/ second, but not knee flexion or hip abduction strength, were related to improvements in selfreported hip function in a cohort of athletic patients with FAIS. Strengthening programs that include targeted knee extensor strengthening during postoperative rehabilitation may improve functional outcomes, especially for patients who demonstrate the poorest function and greatest knee extension strength deficits pre-operatively, but this hypothesis warrants evaluation. Future investigation is needed to further identify modifiable lower extremity musculoskeletal impairments that can influence functional outcomes after hip arthroscopy in order to inform evidence-based clinical care for in this population of athletes.

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4. Leunig M, Beaulé, Ganz R. The concept of femoroacetabular impingement: current status and future perspectives. Clin Orthop Relat Res. 2009;467:616-622.

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6. Sankar WN, Nevitt M, Parvizi J, Felson DT, Agricola R, Leunig M. Femoroacetabular impingement: defining the condition and its role in the pathophysiology of osteoarthritis. J Am Acad Orthop Surg. 2013;21(suppl 1):S7-S15.

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Byrd JW, Jones KS. Arthroscopic management of femoroacetabular impingement in athletes. Am J Sports Med. 2011;39(1):7S-13S. Malviya A, Paliobeis CP, Villar RN. Do professional athletes perform better than recreational athletes after arthroscopy for femoroacetabular impingement? Clin Orthop Relat Res. 2013;471:24772483.

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Eitzen I, Holm I, Risberg MA. Preoperative quadriceps strength is a significant predictor of knee function two years after anterior cruciate ligament reconstruction. Br J Sports Med. 2009;43:371-376.

Holstege MS, Lindeboom R, Lucas C. Preoperative quadriceps strength as a predictor for short-term functional outcome after total hip replacement. Arch Phys Med Rehabil. 2011;92:236-241.

Zwolski C, Schmitt LC, Quatman-Yates C, Thomas S, Hewett TE, Paterno MV. The influence of quadriceps strength asymmetry on patient-reported function at time of return to sport after anterior cruciate ligament reconstruction. Am J Sports Med. 2015 Sep;43(9):2242-9.

Di Stasi SL, Logerstedt D, Gardinier ES, SnyderMackler L. Gait patterns differ between ACLreconstructed athletes who pass return-to-sport criteria and those who fail. Am J Sports Med. 2013 Jun;41(6):1310-8.

Ithurburn MP, Paterno MV, Ford KR, Hewett TE, Schmitt LC. Young Athletes With Quadriceps Femoris Strength Asymmetry at Return to Sport

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Spencer-Gardner L, Eischen JJ, Levy BA, Sierra RJ, Engasser WM, Krych AJ. A comprehensive fivephase rehabilitation programme after hip arthroscopy for femoroacetabular impingement.

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Wahoff M, Dischiavi S, Hodge J, Pharez JD. Rehabilitation after labral repair and femoroacetabular decompression: criteria-based progression through the return to sport phase. Int J Sports Phys Ther. 2014;9(6):813-826.

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Arthroscopy. 2007;23(8):822-826.

Hinman RS, Dobson F, Takla A, O’Donnell J, Bennell KL. Which is the most useful patient-reported

outcome in femoroacetabular impingement? Testretest reliability of six questionnaires. Br J Sports Med. 2014;48:458-463.

30. Kemp JL, Collins NJ, Roos EM, Crossley KM. Psychometric properties of patient-reported outcome measures for hip arthroscopic surgery. Am J Sports Med. 2013;41(9):2065-2073.

31. Harris-Hayes M, McDonough CM, Leunig M, Lee CB, Callaghan JJ, Roos EM. Clinical outcomes assessment in clinical trials to assess treatment of femoroacetabular impingement: use of patient reported outcome measures. J Am Acad Orthop Surg.

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32. Li RC, Wu Y, Maffulli N, Chan KM, Chan JL. Eccentric and concentric isokinetic knee flexion and extension: a reliability study using the Cybex 6000 dynamometer. Br J Sports Med. 1996 Jun;30(2):15660.

33. Barber-Westin SD, Noyes FR. Factors used to determine return to unrestricted sports activities after anterior cruciate ligament reconstruction.

Arthroscopy. 2011;27(12):1697-1705.

34. Thorborg K, Petersen J, Magnusson SP, Hölmich P. Clinical assessment of hip strength using a handheld dynamometer is reliable. Scand J Med Sci Sports.

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35. Rydevik K, Fernandes L, Nordsletten L, Risberg MA. Functioning and disability in patients with hip osteoarthritis with mild to moderate pain. J Orthop Sports Phys Ther. 2010;40(10):616-624.

36. Harris-Hayes M, Mueller MJ, Sahrmann SA, Bloom NJ, Steger-May K, Clohisy JC, Salsich GB. Persons with chronic hip joint pain exhibit reduced hip muscle strength. J Orthop Sports Phys Ther.

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37. Phong T, Pritchard M, O’Donnell J. Outcome of arthroscopic treatment for cam type femoroacetabular impingement in adolescents. ANZ J Surg. 2013;83:382-386.

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IJSPT

ORIGINAL RESEARCH

EFFECT OF DIFFERENT FOAM ROLLING VOLUMES ON KNEE EXTENSION FATIGUE Estêvão Rios Monteiro1 Victor Gonçalves Corrêa Neto1,2

ABSTRACT Background: Foam rolling (FR) is a common intervention utilized for the purpose of acutely increasing range-ofmotion without subsequent decreases in performance. FR is characterized as an active technique which subject performs upon themselves. Thus, it is believed that the accumulated fatigue can influence whether the task can be continued.

Purpose: To analyze the effect of different foam rolling volumes on fatigue of the knee extensors.

Methods: Twenty-five recreationally active females (age 27.7 ± 3.56 y, height 168.4 ± 7.1 cm, weight 69.1 ± 10.2 kg) were recruited for the study. The experiment involved three sets of knee extensions with a pre-determined 10 repetition maximum load to concentric failure. Then, subjects performed the control (CONT) and foam rolling (FR) conditions. FR conditions consisted of different anterior thigh rolling volumes (60-, 90-, and 120-seconds) which were performed during the inter-set rest period. After that, the fatigue index was calculated and compared between each experimental condition. Fatigue index indicates how much (%) resistance the subjects experienced, calculated by the equation: (thidset/firstset) x 100.

Results: Fatigue index was statistically significantly greater (greater fatigue resistance) for CONT compared to FR90 (p = 0.001) and FR120 (p = 0.001). Similarly, higher fatigue resistance was observed for FR60 when compared to FR120 (p = 0.048). There were no significant differences between the other conditions (p > 0.005).

Conclusion: The finding of foam rolling fatigue index decline (less fatigue resistance) as compared to control conditions may have implications for foam rolling prescription and implementation, in both rehabilitation and athletic populations. For the purposes of maximum repetition performance, foam rolling should not be applied to the agonist muscle group between sets of knee extensions. Moreover, it seems that volumes greater than 90-seconds are detrimental to the ability to continually produce force.

Level of evidence: 2b Keywords: Massage, neuromuscular fatigue, self-myofascial release, strength

1

Department of Gymnastics, School of Physical Education and Sports, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil 2 Gama e Souza College, Rio de Janeiro, Brazil ACKNOWLEDGMENTS We would like to acknowledge the contributions of all participating. We are grateful for the English revision by Brent Wakefield and the mechanisms response by Andrew Vigotsky and Jakob Škarabot.

CORRESPONDING AUTHOR Estêvão Rios Monteiro Department of Gymnastics School of Physical Education and Sports Federal University of Rio de Janeiro 540 Carlos Chagas Filho Avenue, 21941-599, Rio de Janeiro, Brazil Phone: +552125626808, Fax: +552125626808 E-mail: profestevaomonteiro@gmail.com

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INTRODUCTION Foam rolling (FR) is a common intervention utilized for the purposes of acutely increasing rangeof-motion (ROM) without subsequent decreases in performance.1,2 Therefore, it is commonly used during the peri-workout period; that is, before, during, or after workouts in athletes and non-athletes. However, the effects of this practice have not yet been fully elucidated. FR has been shown to bring about acute increases in ROM without decreases in performance1,3,4, reduce delayed onset muscle soreness after exercise5,6, and improve vascular endothelial function and reduce arterial stiffness.7 FR is characterized as an active technique which subject performs upon themselves. Thus, it is believed that the accumulated fatigue could negatively influence the ability to continue activity.8-10 Most studies have focused on ROM effects and strength activities (i.e. maximum repetition performance); little research has focused on the effects of FR on fatigue during resistance training. To the authors’ knowledge, only two studies to date have investigated the effects of FR on a fatigue during resistance training. The first study observed maximum repetition performance of knee extension after anterior thigh inter-set FR in different volumes (60-, 90- and 120-seconds).11 The second study utilized hamstring inter-set FR in different volumes (60- and 120-seconds) and observed maximum repetition performance of knee extension.12 Both studies found a dose-response decrease in repetition performance with greater amounts of FR volume.

The mechanism by which greater FR dose decreases maximum repetition performance remains unclear.

While foam rolling has been used for various purposes, including warm-up and motion preparation for athletes and non-athletes, there is a lack of evidence regarding the effects of accumulated fatigue on maximum repetition performance. Thus, the purpose of this study was to analyze the effect of different foam rolling volumes on fatigue of the knee extensors.

Table 1. Means ± SD for subject’s characteristics.

Age (years)

27.7 ± 3.56

Height (cm)

168.4 ± 7.1

BM (kg)

69.1 ± 10.2

BMI (m²/kg)

24.2 ± 2.0

RTE (months)

23.0 ± 6.5

KE 10RM test (kg)

70.7 ± 11.0

KE 10RM retest (kg)

71.4 ± 11.2

BM = Body Mass; BMI = Body Mass Index; RTE = Resistance Training Experience; KE = knee extension.

calculation14 (Effect Size = 3.67; β = 0.95; α = 0.05) using G*Power (Universität kiel, Germany)15 found that eight subjects would be adequate, however, in order to increase statistical power, twenty-five were recruited. Subjects performed the resistance procedures in the luteal phase of the menstrual cycle.16 Before the experimental protocols anthropometric data were collected including body mass (Techline BAL – 150 digital scale, São Paulo, Brazil), and height (Stadiometer ES 2030 Sanny, São Paulo, Brazil).

Subjects were included if they were experienced in the use of knee extension machine exercises for at least one-year prior the experiment, 3-4 session per week, and using loads that allowed participants to perform to 8-12 maximum repetitions. Subjects were free from any functional limitations or medical conditions that could have compromised their health or confounded results of the study. During the thirteen-day period of data collection the subjects were instructed not to engage in any lower body resistance training exercise or other strenuous activities. Prior to the study all participants were provided verbal explanation of the study and read and signed informed consent and Physical Activity Readiness Questionnaire.17 All procedures were in accordance with Declaration of Helsinki. The local ethics committee approved the study (57023616.7.0000.5257/16).

Procedures

METHODS Subjects Twenty-five recreationally active females13 (Table 1) were recruited for the study. A priori sample size

Ten repetition maximum testing Ten repetition maximum (10RM) testing and retesting was performed using a methodology similar to the protocol of Bentes et al18 with an interval of 48

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hours between the two days. A maximum of three trials were allowed per testing session, separated by three minutes of recovery. The higher load between the two testing days was considered as the 10RM load.

Reliability of the method to determine the 10RM load was confirmed by calculating the intraclass correlation coefficient (ICC). Subjects initially performed a standardized warm up consisting of fifteen repetitions of knee extensions with self-selected load, approximately 50% of a normal training load. After the warm up, ten-repetition maximum testing was performed. Pace of the knee extension exercise was standardized using a metronome (Metronome Plus, version 2.0, M&M System, Braugrasse, Germany) to two seconds for both phases of the movement.

In an effort to minimize variability in performance between individuals, the following strategies were adopted:19 a) all subjects received standardized instructions about the exercise technique and data collection, b) subjects received feedback as to their technique and were corrected if appropriate, and c) all subjects were verbally encouraged. The knee extension apparatus used for 10 RM testing and during the experimental sessions was the same (Selection Line Leg Extension, Technogym, Cesena, Italy).

Foam rolling Foam rolling composed of a hard inner core enclosed in a layer of ethylene vinyl acetate foam was used (The Grid Foam Roller, Trigger Point Technologies, 5321 Industrial Oaks Blvd., Austin, Texas 78735, USA). This kind of foam roller has been shown to produce more pressure on the soft tissue than those made out of polystyrene foam.20 FR was performed bilaterally in anterior thigh in a prone position while maintaining the legs extended (in contact with the foam roller), but relaxed. Subjects were instructed to move their body back and forward to apply pressure between the acetabulum and patellar tendon. As per randomization, FR was performed during the interset rest period for 60-, 90-, or 120-seconds. For better representation of real work training environments, subjects were free to choose the pace at which they performed the foam rolling.

Experimental Approach to the Problem A randomized (aleatory entry in latin square format), cross-over, within-subjects design was used

Figure 1. Experimental protocols design. CONT = control experimental condition; FR60 = foam rolling for 60 seconds; FR90 = foam rolling for 90 seconds; FR120 = foam rolling for 120 seconds.

(Figure 1). Subjects visited the laboratory on six occasions during a thirteen-day period with at least forty-eight hours between the visits. During the first two visits the subjects underwent a 10RM testing and retesting, respectively. Following, four experimental visits followed in a randomized order, which included: 1) control experimental condition (CONT) with four-minutes passive rest interval, 2) foam rolling for 60 seconds (FR60), 3) foam rolling for 90 seconds (FR90), and 4) foam rolling for 120 seconds (FR120). Each experimental session consisted in three sets of knee extension at 100% of 10RM load to concentric muscle failure, interspersed by fourminute rest intervals, with the goal of completing the maximum number of repetitions without losing the movement pattern. FR was performed between sets on the inter-set rest period.

Statistical analyses Data are presented as means Âą standard deviations. Initially, the neuromuscular fatigue index (FI) was calculated using the equation proposed by Dipla et al.21, where a higher percentage value (%) indicates a superior fatigue resistance: FI = (thirdset / firstset) x 100. Normality and sphericity were tested using a Shapiro Wilks test and homoscedasticity was confirmed by a Mauchlyâ&#x20AC;&#x2122;s test. Repeated measures ANOVA was used to compare the fatigue

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index across four conditions (CONT, FR60, FR90 and FR120). If a significant effect of condition was found, a Tukey HSD post-hoc test was used to identify significant differences between individual conditions.

All analyses were performed using SPSS version 20 (SPSS Inc., Chicago, IL, USA) and an alpha level of 0.05 was used.

RESULTS The reliability of 10RM testing was determined by calculating an intraclass correlation coefficient for women (r = 0.981, 95%CI=0.966 to 0.996).

There was a difference in mean fatigue index across the four conditions (F = 8.184; p < 0.001) as shown in Table 2. Fatigue index indicating greater fatigue resistance for CONT when compared to FR90 (p = 0.001) and FR120 (p < 0.001). Similarly, higher fatigue resistance was observed for FR60 when compared to FR120 (p = 0.048). There were no significant differences between the other conditions (p > 0.005).

DISCUSSION The purpose of this study was to analyze the effect of different foam rolling volumes on fatigue of the knee extensors. Fatigue indices indicating greater fatigue resistance were seen in CONT comparee to FR90 (p = 0.001) and FR120 (p < 0.001). Similarly, higher fatigue resistance was observed for FR60 when compared to FR120 (p = 0.048). These results confirmed the initial hypothesis, which suggested that higher volumes of FR promote higher muscular fatigue. The results are in accordance with the works of previous authors who investigated the effects of rest interval on fatigue9,22,23 and also with previous unpublished Table 2. Means ± standard deviations for each knee extension condition Set 1

Set 3

FI

CONT

10.24 ± 0.43

9.48 ± 0.50

98.48 ± 5.80

FR60

9.64 ± 0.48

8.56 ± 0.86

88.68 ± 9.01

FR90

10.00 ± 0.57

8.52 ± 0.65

84.44 ± 7.54#

FR120

9.60 ± 0.5

8.00 ± 0.64

83.16 ± 6.95#*

CONT = experimental control condition; FR60 = foam rolling for 60 seconds; FR90 = foam rolling for 90 seconds; FR120 = foam rolling for 120 seconds;FI = fatigue index. # Statistically significant difference between FR90 and FR120; * Statistically significant difference between FR60 and FR120.

work by the authors on inter-set foam rolling applied to the antagonist muscle group;11,12 which found a dose-response decrease in repetition performance with greater volume of FR (120> 90> 60).

Maximum repetition performance depends directly on the ability to maintain intensity during set progression.24 Several factors can influence the maintenance of task performance (fatigue). Maia et al22 observed that the exercise order had a negative influence on maximum repetition performance. Tibana et al9 observed the same results on rest interval less than 30 seconds (120> 60> 30) in high intensity and low range between sets. Therefore, it is possible that the fatigue generated by the FR activity may have interfered in the knee extension performance. Monteiro et al.12 observed a dose-dependent response in which longer durations of foam rolling the hamstrings hindered maximum repetition performance.

The mechanisms by which FR works are not fully understood. However, a number of underlying mechanical and neurophysiological1 mechanisms have been proposed and investigated. Changes in fascial components (i.e. adhesions, piezoelectricity, myofascial trigger points, and viscoelastic properties of tissue)25 influenced by collagen remodeling and changes in elastin are possible reasons for the ROM and muscle force increases seen after foam rolling.1,26 However, at present, these mechanisms are not supported by the literature. Secondly, central command response of activation of mechanoreceptors may cause withdrawal of parasympathetic predominance and increase sympathetic activation.7,27,28 Third, endogenous opioid response may modulate the perception of effort.11,12,29 Fourth, the mechanoreceptors inside the muscle and fascia may directly influence a decrease muscle tone.1,30-32 Finally, opioid activity has been implicated during fatiguing conditions acting by attenuating the afferent motor feedback from agonist musculature, resulting in greater power output in the beginning of an exercise, which eventually leads to excess peripheral muscle fatigue.29 There are a number of limitations and delimitations to bear in mind when interpreting the results of the present study. First, this present study utilized female subjects, so these results cannot be extrapolated to men. Janot et al9 indicated that women are

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more susceptible to fatigue during dynamic contractions. Women have a difference in power output during the different phases of the menstrual cycle and trends powerfully on luteal phase. To minimize these effects, all were tested in the luteal phase.15 Finally; the pace of each roll on the FR was not controlled. This can be considered as both a limitation and strength of this design. Specifically, the lack of control reduces the internal validity of the results, as the number/duration of rolls during a time period could possibly influence the outcome. Conversely, the freedom to choose the pace duration of each roll enhances to ecological validity of the finding, as it better represents real-life training scenarios.

CONCLUSION Intraset foam rolling seems to decrease in maximum repetition performance as compared to a control conditions. These findings have implications for foam rolling prescription and implementation, in both athletic and non-athletic populations. For the purposes of maximum repetition performance in females, foam rolling should not be applied to the agonist muscle group between sets of knee extensions. Moreover, it seems that volumes greater than 90-seconds are detrimental to the ability to continually produce force.

REFERENCES 1. Beardsley C, Škarabot J. Effects of self-myofascial release: A systematic review. J Bodyw Mov Ther.

2015; 19:747-758.

2. Schroeder AN, Best TM. Is self myofascial release an effective preexercise and recovery strategy? A literatura review. Curr Sports Med Rep. 2015; 14:200-208.

3. Škarabot J, Beardsley C, Stirn I. Comparing the effects of self-myofascial release with static stretching on ankle range-of-motion in adolescent athletes. Int J Sports Phys Ther. 2015; 10:203-212.

7. Okamoto T, Masuhara M, Ikuta K. Acute effects of selfmyofascial release using a foam roller on arterial function. J Strength Cond Res. 2014; 28:69-73.

8. Boyas S, Guevel A. Neuromuscular fatigue in healthy muscle: Underlying factors and adaptation mechanisms. Ann Phys Rehabil Med. 2011; 54:88-108.

9. Tibana RA, Prestes J, Nascimento Dda, et al. Higher muscle performance in adolescents compared with adults after a resistance training session with different rest intervals. J Strength Cond Res. 2012; 26:1027-1032.

10. Janot J, Malin B, Cook R, et al. Effects of Self Myofascial Release and Static Stretching on Anaerobic Power Output. Journal of Fitness Research.

2013; 2:41-54.

11. Monteiro ER, Vigotsky AD, Škarabot J, et al. Acute effects of different foam rolling volumes in the inter-set rest period on maximum repetition performance. Manuscript submitted for publication.

Hong Kong Physiotherapy Journal. 2016.

12. Monteiro ER, Škarabot J, Vigotsky AD, et al.

Maximum repetition performance after different antagonist foam rolling volumes in the inter-set rest period. Manuscript submitted for publication. Int J Sports Phys Ther. 2016 13. American College of Sports Medicine – ACSM’s position stand. Progression models in resistance training for healthy adults. Med Sci Sports Exerc.

2009; 41:687-708.

14. Beck TW. The importance of a priori sample size estimation in strength and conditioning research. J Strength Cond Res. 2013; 27:2323–37.

15. Faul F, Erdfelder E, Lang AG, et al. G*Power 3: a flexible statistical power analysis program for the social, behavioral, and biomedical sciences. Behav Res Methods. 2007; 39:175-191.

16. Markofski MM, Braun WA. Influence of menstrual cycle on indices of contraction-induced muscle damage. J Strength Cond Res. 2014; 28:2649–56.

17. Shephard RJ. PAR-Q, Canadian Home Fitness Test and exercise screening alternatives. Sports Med. 1988; 5:185–95.

4. Vigotsky AD, Lehman GJ, Contreras B, et al. Acute effects of anterior thigh foam rolling on hip angle, knee angle, and rectus femoris length in the modified Thomas test. PeerJ 3: e1281, 2015.

18. Bentes CM, Simão R, Bunker T, et al. Acute effects of dropsets among different resistance training methods in upper body performance. J Hum Kin. 2012; 34:105-111.

5. Macdonald GZ, Button DC, Drinkwater EJ, et al. Foam rolling as recovery tool after an intense bout of physical activity. Med Sci Sports Exerc. 2014; 46:131-142.

19. Miranda H, Maia MF, Paz GA, et al. Acute effects of antagonist static stretching in the inter-set rest period on repetition performance and muscle activation.

Research in Sports Medicine. 2015; 23:37-50.

6. Pearcey GEP, Bradbury-Squires DJ, Kawamoto JE, et al. Foam rolling for delayed-onset muscle soroness and recovery of dynamic performace measures. J Athl Train. 2015; 50:5-13.

20. Curran PF, Fiore RD, Crisco JJ. A comparison of the pressure exerted on soft tissue by 2 myofascial rollers. J Sport Rehabil. 2008; 17:432–442.

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21. Dipla K, Tsirini T, Zafeiridis A, et al Fatigue resistance during high-intensity intermittent exercise from childhood in males and females. Eur J Appl Physiol. 2009; 106:645-653.

22. Maia MF, Paz GA, Miranda H, et al. Maximal repetition performance, rating of perceived exertion, and muscle fatigue during paired set training performed with different rest intervals. J Exerc Sci Fitness. 2015; 13:104-110.

23. Ribeiro AS, Avelar A, Schoenfeld BJ, et al. Effect of 16 weeks of resistance training on fatigue resistance in men and women. J Hum Kinet. 2014; 42:165-174.

24. Willardson JM. A brief review: factors affecting the length of the rest interval between resistance exercise sets. J Strength Cond Res. 2006; 20:978-984.

25. Stecco C, Stern R, Porzinato A, et al. Hyaluronan within fascia in the etiology of myofascial pain. Surg Radiol Anat. 2011; 33:891-896.

26. Schleip R. Fascial plasticity- a new neurobiological explanation: Part 2. J Bodyw Mov Ther. 2003; 7:104-116.

27. Drew RC, Bell MP, White MJ. Modulation of spontaneous baroreflex control of heart rate and

indexes of vagal tone by passive calf muscle stretch during graded metaboreflex activation in humans. J Appl Physiol. 2009; 104:716-723.

28. Bialosky JE, Bishop MD, Price DD, et al. The mechanisms of manual therapy in the treatment of musculoskeletal pain: a comprehensive model. Man Ther. 2009; 14:531-538.

29. Amann M, Proctor LT, Sebranek JJ, et al. Opioidmediated muscle afferents inhibit central motor drive and limit peripheral muscle fatigue development in humans. J Physiol. 2009; 587:271-283.

30. Goldberg J, Sullivan SJ, Seaborne DE. The effect of two intensities of massage on H-reflex amplitude.

Phys Ther. 1992; 72:449-457.

31. Sullivan SJ, Williams LR, Seaborne DE, et al. Effects of massage on alpha motoneuron excitability. Phys Ther. 1991; 71:555-560.

32. Vigotsky AD and Bruhns RP. The Role of Descending Modulation in Manual Therapy and Its Analgesic Implications: A Narrative Review. Pain Research and Treatment 2015: 11, 2015.

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IJSPT

ORIGINAL RESEARCH

MEASURING SPORT-SPECIFIC PHYSICAL ABILITIES IN MALE GYMNASTS: THE MEN’S GYMNASTICS FUNCTIONAL MEASUREMENT TOOL Mark D. Sleeper, PT, MS, DPT, PhD, OCS Lisa K. Kenyon, PT, DPT, PhD, PCS James M Elliott, PT, PhD M. Samuel Cheng, PT, MS, ScD

ABSTRACT Purpose/Background: Despite the availability of various field-tests for many competitive sports, a reliable and valid test specifically developed for use in men’s gymnastics has not yet been developed. The Men’s Gymnastics Functional Measurement Tool (MGFMT) was designed to assess sport-specific physical abilities in male competitive gymnasts. The purpose of this study was to develop the MGFMT by establishing a scoring system for individual test items and to initiate the process of establishing test-retest reliability and construct validity.

Methods: A total of 83 competitive male gymnasts ages 7-18 underwent testing using the MGFMT. Thirty of these subjects underwent re-testing one week later in order to assess test-retest reliability. Construct validity was assessed using a simple regression analysis between total MGFMT scores and the gymnasts’ USA-Gymnastics competitive level to calculate the coefficient of determination (r2). Test-retest reliability was analyzed using Model 1 Intraclass correlation coefficients (ICC). Statistical significance was set at the p<0.05 level.

Results: The relationship between total MGFMT scores and subjects’ current USA-Gymnastics competitive level was found to be good (r2 = 0.63). Reliability testing of the MGFMT composite test score showed excellent test-retest reliability over a one-week period (ICC=0.97). Test-retest reliability of the individual component tests ranged from good to excellent (ICC = 0.75-0.97).

Conclusions: The results of this study provide initial support for the construct validity and test-retest reliability of the MGFMT. Key Words: Functional measurement, gymnastics, physical abilities Level of Evidence: Level 3

1

University at Buffalo, State University of New York, Buffalo, New York, USA 2 Grand Valley State University, Grand Rapids, Michigan. USA 3 Northwestern University, Chicago, Illinois, USA 4 Nova Southeastern University, Fort Lauderdale, Florida, USA This study protocol was approved by the Northwestern Institutional Review Board and the Nova Southeastern Institutional Review Board Acknowledgements The authors would like to thank Mark Diab, Tim Erwin, Bryan Kiser, Kevin Mazeika and Don McPherson for their expert guidance and for generously letting us use their gymnastics facilities.

CORRESPONDING AUTHOR Mark D. Sleeper, PT, MS, DPT, PhD, OCS Clinical Associate Professor Department of Rehabilitation Science University at Buffalo, State University of New York Buffalo, New York USA E-mail: markslee@buffalo.edu

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INTRODUCTION Five million young gymnasts, defined as being at least six years of age, participate in formal gymnastics related activities each year in the United States (US).1 While the vast majority of these young athletes are female, 25% (~ 1.3 million) of the representative gymnastic athletes are young males. Approximately 12,000 of these young male gymnasts compete in the US Junior Olympic program while the remaining primarily participate in activities through the Amateur Athletic Union, the Young Men’s Christian Association, and other organizations. In addition to these programs, the number of male gymnasts competing at the high school and collegiate levels in the US is reportedly on the rise.1 As opposed to the four events that comprise women’s gymnastics, male gymnasts compete in six events: the floor exercise, pommel horse, vault, still rings, parallel bars, and horizontal bar (also known as the high bar).

Flexibility,2-8 speed,6,9-11 power,7,8,12,13 strength,5,6,14,15 muscular endurance,14 agility,16 and balance17,18 have all been associated with competitive gymnastics and may also relate to a gymnast’s ability to sustain injuryfree and long-term participation in the sport.8,17,19 As such, it is imperative that coaches, athletic trainers, therapists, and other health care providers be able to objectively measure and monitor an individual gymnast’s physical abilities as a means of promoting healthy, injury-free participation in the sport.

Within USA-Gymnastics, a system of competitive levels (ranging from a low of 4 to a high of 10) is used to rank the skills and abilities of individual gymnasts.

Moving from one level to the next requires that a gymnast attain a specific all-around score as well as be able to perform specific gymnastics skills that increase in difficulty as the competitive level increases. Each increasing competitive level thus places increased demands on a gymnast in regards to higher levels of technical skill and mental acuity in tandem with increased levels of physical ability (e.g. strength, power, speed, flexibility, balance and agility).16 At the forefront of the USA-Gymnastics program is the need to identify talented young gymnasts for both individual and team level competition.20-25 Screening the available population for the best possible athletes however, has historically been based upon the opinion

of “experts” in the sport with very little, if any, consideration of objective metrics.26 With an increasing push for excellence, national and international stakeholders in the sport have placed an increased emphasis on identifying individuals with the potential to become an elite-level gymnast. For example, through USAGymnastics, the US has instituted an extensive talent identification program for male gymnasts called Future Stars.25 Future Stars is designed exclusively for boys ages 8 to 13 and consists of selected gymnastics skills and compulsory routines plus strength and flexibility evaluations. It is used primarily with club gymnasts to identify competitive potential and to aid in the development of the US competitive gymnastics program and was not designed to assess the gymnasticspecific physical abilities of individual athletes. Future Stars also was not designed to address the needs of gymnasts of all ages or those who compete through high school or collegiate programs. While specialized training is needed to administer the Future Stars program, the reliability and validity of the Future Stars testing procedures have not been reported.

In contrast to screening for talent, field-testing is often used to assess an athlete’s sport-related physical abilities.27-34 Some field-tests focus on a specific aspect of sports function (such as the hop test 35 or the agility T-test36) while other tests, such as the Functional Movement Screen™,37,38 consist of a series of individual items designed to assess an athlete’s abilities across multiple aspects of function. Sportsspecific field-tests focus on assessing the specific physical abilities and attributes necessary for successful participation in a particular sport.24,27,29,30,34-36 Although establishing the reliability and validity of a tool is a multi-dimensional and on-going process, currently there is not a reliable and valid test to evaluate the sport-specific physical abilities needed for competition in men’s gymnastics. Grabiner and McKelvain developed a physical fitness testing battery for male gymnasts, but did not report reliability or validity data.21 The recently developed Gymnastics Functional Measurement Tool (GFMT) has been shown to have good test-retest reliability and construct validity, but, it was only developed for female gymnasts.39 The Men’s Gymnastics Functional Measurement Tool (MGFMT) was thus developed to allow coaches, athletic trainers, and other health professionals to

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Table 1. Individual Items Comprising the Men’s Gymnastics Functional Measurement Tool

measure a gymnast’s overall physical abilities while minimizing the impact of gymnastic skill on testing scores.40,41 The individual test items included in the MGFMT (Table 1) were developed based on a set of criteria including: 1) the test item had to be easy to apply without requiring specialized equipment, 2) the test item had to reflect physical abilities inherent in male gymnastics skills and activities, 3) the test item had to be quantitative, 4) the test item had to measure flexibility, strength, power, agility or balance of one or multiple body segments and 5) the test item would not require a tester to have previous or current skills in gymnastics. All items on the MGFMT thus had to be able to be performed by a non-gymnast. Detailed information regarding administration of each test item is provided in Appendix I. The purpose of this study was to develop a scoring system for the MGFMT (both for individual test items and for a composite score) and to begin the process of establishing the reliability and validity of the MGFMT. METHODS Approval for the study was obtained from the Office for the Protection of Research Subjects at Northwest-

ern and Nova Southeastern Universities. Competitive male gymnasts were recruited from five different private gymnastics clubs throughout Illinois and Texas. Inclusion criteria required the subjects to be male, between 7 and 18 years of age, regularly practicing gymnastics three to six days per week, and competing in gymnastics at USA-Gymnastics levels 4 to 10. Exclusion criteria included musculoskeletal pathology currently limiting the gymnast’s ability to train or compete; a history of, or current systemic illnesses including cardiovascular or pulmonary disease; musculoskeletal disease or rheumatoid arthritis; and a lack of informed assent given by the subject or consent given by the parent/legal guardian. The total number of gymnasts tested at each competitive level was based on a sample of convenience and thus the number of gymnasts tested at each level varied. A total of 83 subjects participated in the study. Figure 1 offers a flowchart reflecting subjects’ participation in the study.

All testing was performed in the subjects’ home gyms or in a gym familiar to the subject. Subjects did not have prior knowledge or exposure to the specific items composing the MGFMT. Each subject provided his own USA-Gymnastics competitive level, which

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Units of measurement for the raw data for each test item are listed in Table 1. Subjects were not intentionally masked as to their item scores. Individual MGFMT items were completed in the following order to help reduce the possible effects of regional fatigue: Hanging Pikes Test, Rings Hold Test, Vertical Jump Test, Shoulder Flexibility Test, Handstand Pushups Tests, Agility Test, Star Excursion Balance Test, Handstand Hold Test, Overgrip Pull-ups Test, and the Splits Test. Subjects were given a minimum of five and a maximum of 15 minutes rest between administrations of each item of the MGFMT. From the 83 total subjects, a random convenience sample of 30 subjects from two gymnastics clubs in Illinois was chosen to participate in test-retest reliability testing. These 30 subjects were retested with the MGFMT one week after initial testing. Testing conditions and administration were consistent between the two administrations of the MGFMT including warm-up and item administration order.

To help ensure that test-retest reliability rather than intra-rater reliability was assessed, testers administered different items from the MGFMT on each of the two administration dates.

Figure 1. Flowchart of Subjectsâ&#x20AC;&#x2122; Participation in the Study.

Statistical Methods was recorded by the testers. Prior to testing, subjects completed their regular, coach-directed warm-up routines without regard to the requirements of the MGFMT. Given that field-tests comprised of multiple items are often administered in stations each consisting of an individual item,40,41 subjects were placed into groups of 5-10 and moved through each of the stations to complete the MGFMT. Data were collected by gymnastics coaches with a minimum of five years of coaching experience, the principal investigator, and another licensed physical therapist with gymnastics experience. In an effort to simulate actual practice patterns, all data collectors were provided with a detailed set of instructions for administering each item on the MGFMT but did not undergo any specialized or extensive training. The principal investigator observed initial data collection to confirm testing was done correctly. Raw data for each item of the MGFMT was recorded in units of measurement that were appropriate for the activity.

Development of the Scoring System The scoring system for the MGFMT was developed utilizing the same method used to develop the scoring system for the GFMT. Raw test item scores in the appropriate units of measurement were recorded for each of the individual test items. These raw scores were used to calculate the range, mean, and standard deviation for each individual item of the MGFMT (n= 83). Data was then transformed to an ordinal scale. In an attempt to reduce the possibility of ceiling and floor effects, five percent of the total range of the raw scores was added to the high score of each item and five percent was subtracted from the low score of each item. The resulting range of scores for each individual item was then divided by 11 to create a 0 to 10 ordinal scale for each individual item on the MGFMT.39 The ordinal scale for each item was used to create a total MGFMT score out of a possible 100 points (10 points for each item). Based on these findings, the scoring for each individual item and for the total MGFMT score were finalized and

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are provided in the MGFMT Score Sheet found in Appendix II. Test-retest and Construct Validity Test-retest reliability was analyzed using Model 1 Intra-class correlation coefficients (ICC).42 Although a process of systematic randomization was not employed in the study, a Model 1 ICC was used to reflect the concept that individual items on the MGFMT were administered on each of the two test dates. The variance assessed was thus restricted to differences in the subjects’ scores in the test-retest design and necessitated the use of a Model 1 ICC. Values for the ICC were interpreted according to these levels of agreement: ‘poor to moderate’ = 0.00-0.75, ‘good’ = 0.75-0.90 and ‘excellent’ = 0.901.00.42,43 In an effort to better graphically represent the test re-test reliability, comparisons of agreement between test day one and test day two were analyzed using a Lin’s Concordance Correlation (LCC) Coefficient (pc). Ranging between 1 (perfect agreement) and -1 (perfect inverse agreement), pc represents the extent to which the compared data deviate significantly from perfect concordance.44 Given previously reported positive relationships between various singular physical abilities and a gymnast’s level of competition with the GFMT,10,14,21,39 it was theorized that the total scores on the MGFMT would vary with a gymnast’s current competitive level. This was based upon the concept that at each increasing competitive level, a gymnast is required to perform increasingly difficult skills that theoretically would require a related increase in the gymnast’s physical abilities. In addition, the competitive level of female gymnasts was used in the construct validation process for the GFMT developed for use with female gymnasts.39 Construct validity was thus evaluated based on the relationship between a gymnast’s physical abilities as measured by the MGFMT and the gymnast’s current level of competition as reflected by the gymnast’s USA-Gymnastics competitive level. A linear regression analysis was performed using a gymnast’s USA- Gymnastics competitive level to predict total MGFMT score. The coefficient of determination (r2) was used to explore this relationship. Statistical significance was set at α = 0.05 level.

RESULTS Of the 105 subjects assessed for eligibility in this study, 83 participated. Twenty-two of the recruited subjects were excluded from the study due to recent injury (n=4) or the lack of a signed informed consent or assent (n=18). The number of subjects representing each competitive level ranged from 6-20.

The mean age of participating subjects was 11.07 (range – 7-18) years with these subjects reporting participation in competitive gymnastics for a mean of 4.36 (range 1-13) years. The mean reported number of hours spent practicing was 8.5 for level 4 gymnasts and 21.4 for level 10 gymnasts. Subject demographics, categorized by USA-Gymnastics competition level, are summarized in Table 2. Mean MGFMT component test item raw scores and standard deviations are presented in Table 3.

Raw scores for all items on the MGFMT demonstrated a normal distribution (skewness = [-]0.56 – [+]1.51). The relationship between the individual component test item raw scores of the MGFMT as well as with the MGFMT total-score and subjects’ current USA-Gymnastics competitive level was evaluated and can be seen in Table 4. Several of the relationships between the individual component raw scores were statistically significant, however, r2 values revealed poor to good relationships between USA-Gymnastics competitive level and individual component raw scores (r2 = 0.004-0.64). The relationship between MGFMT total-scores (out of a possible score of 100) and the subjects’ current USA-Gymnastics competitive level was found to be good (r2 = 0.63) and can be observed graphically in Figures 2 and 3. To rule out alternative explanations for the relationship between USA-Gymnastics competitive level and MGFMT total-scores, the relationships between MGFMT total-scores and age, MGFMT totalscores and bodyweight as well as MGFMT total-score and hours of training per week were also explored.

Statistically significant relationships were identified between MGFMT total-score and age (r2 = 0.48), between MGFMT total-score and bodyweight (r2 = 0.30) and between MGFMT total-score and hours of training per week (r2 = 0.56).

Raw item scores were used to examine the test-retest reliability for each item on the MGFMT. Test-retest reliability of total MGFMT scores was also deter-

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Table 2. Subject Demographics by USA-Gymnastics Competitive Level

Table 3. Mean and Standard Deviation of MGFMT Individual Item Scores and Total Menâ&#x20AC;&#x2122;s Gymnastics Functional Measurement Tool Scores (n= 83)

mined. Reliability testing of the MGFMT total score showed good test-retest reliability over a one-week period (ICC=0.97). Test-retest reliability coefficients are shown in Table 5. A statistically significant differ-

ence (p<0.05) between the first and second test scores was identified for the MGFMT Total score and for the following test items: Hanging Pikes Test, Agility Test, Vertical Jump Test, Start Excursion Balance Test. Test-

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Table 4. Relationship between Men’s Gymnastics Functional Measurement Tool (MGFMT) Individual Item Raw Score and Total MGFMT Score and the Subjects’ Current USA-Gymnastics Competitive Level, Age, and Body Weight (n = 83)

Figure 2. The Relationship between the Men’s Gymnastics Functional Measurement Tool (MGFMT) Total Score and Subjects’ USA-Gymnastics Competitive Level.

retest reliability of the individual component items was good (ICC = 0.70-0.92). Test-retest reliability testing of the MGFMT total-score showed excellent testretest reliability over a one-week period (ICC=0.97).

DISCUSSION The MGFMT is a functional tool designed to assess the unique physical abilities that are necessary for

participation in men’s gymnastics. The procedures and methods used in this study allowed the researchers to evaluate the MGFMT within the context of its intended use as a field test to assess sport-specific physical performance characteristics of male gymnasts.40,41 As such, testing was conducted in a manner consistent with the sport in an environment familiar to the individual athletes. Given that the MGFMT

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male competitive gymnasts.17 In his comprehensive analysis, Sands19 suggested that a gymnast routinely and repeatedly performs difficult skills but may not possess the overall physical abilities and fitness levels necessary for prolonged, successful participation in the sport.11 In competitive gymnastics, an annual injury rate as high as 294% in male and female club gymnasts in the United States has been reported.45-47 Using the MGFMT to identify deficits in sport-specific physical abilities that can be targeted as part of a gymnast’s individual training regime may prove useful in injury prevention. Future studies should explore use of the MGFMT to identify and remediate injury risk in male gymnasts.

Figure 3. Lin Concordance Coefficient Correlation for Testretest Reliability of the Men’s Gymnastics Functional Measurement Tool (MGFMT) Total Score

can be administered without extensive training using equipment readily available in a gymnastics gym, the authors believe that the MGFMT can be easily incorporated into any gymnastics program.

An improved ability to accurately measure strength, power, speed, balance, flexibility, and agility may assist in identifying and remediating deficits in the physical performance characteristics needed by

The results of this study provide initial support for the construct validity and test-retest reliability of the MGFMT. Although construct validity is only one of the many forms of validity to be considered when evaluating a measurement tool,42,48 the relationship between a gymnast’s total MGFMT score and current USA-Gymnastics competitive level provides support for the concept that like the GFMT, MGFMT scores will vary based on a gymnast’s current competitive level. Examining data from the individual items comprising the MGFMT reveals that certain physical attributes such as power appear to relate more strongly to a gymnast’s current competitive level than flexibility. Despite the variations in the strength of the relationship between individual items and competitive level, the authors believe that to completely assess a gymnast’s physical abili-

Table 5. Score Means and Standard Deviations for Both Test Days and Intraclass Correlation Coefficients for Test Retest Reliability (n=30)

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ties across multiple domain areas (strength, flexibility, power, etc.), all items on the MGFMT must be administered. Maintaining the complete representation of gymnastics specific physical abilities within the MGFMT is necessary in order to adequately identify a gymnast’s deficits in physical abilities and may aid in the development of a program tailored to address individual needs.

This study was limited by several factors. The total number of participants at any given USA-Gymnastics competitive level ranged from 9 to 21. Increasing the number of participants at each USA-Gymnastics competitive level may have yielded different results.

While attempts were made in the test-retest procedures to decrease the possibility of a practice or learning effect, the authors’ recognize that such factors may have impacted score differences between the first and second administrations of the MGFMT. In addition, the participants included in the study were from a limited number of gymnastics clubs in two specific States: Illinois and Texas. The outcomes of this research also may have been impacted by the training practices routinely performed in these two geographic areas.

Further research is needed to continue the process of establishing the various types of reliability and validity of the MGFMT. Future studies should also explore the ability of the MGFMT total score and individual item scores to identify a gymnast’s risk for specific injuries and whether the MGFMT could be used to help determine if and when an injured gymnast can safely resume high-level training and competition.

CONCLUSION While it is well understood that participation in the sport of gymnastics exposes the athlete to a significant risk of injury, there appears to be a direct relationship between the competitive level at which a gymnast competes and the occurrence as well as the type of injury that is most likely to occur.45,49 However, attempting to reduce the injury rate in competitive men’s gymnastics is a very complex multifaceted endeavor. The establishment of a gymnastics-specific field test, which assesses the physical abilities of male gymnasts, is a first step in a myriad of possible solutions. The information gained through use

of the MGFMT may assist coaches and healthcare providers in identifying and subsequently improving the physical abilities of competitive male gymnasts across the globe.

REFERENCES 1. USA-Gymnastics. USA Gymnastics Demographics. https://usagym.org/pages/aboutus/pages/demo graphics.html?prog=pb. Accessed November 3, 2016.

2. Kirby RL, Simms FC, Symington VJ, Garner JB. Flexibility and musculoskeletal symptomatology in female gymnasts and age-matched controls. Am J Sports Med. 1981;9(3):160-164.

3. Knapik JJ, Bauman CL, Jones BH, Harris JM, Vaughan L. Preseason strength and flexibility imbalances associated with athletic injuries in female collegiate athletes. Am J Sports Med. 1991;19(1):76-81.

4. Knapik JJ, Jones BH, Bauman CL, Harris JM. Strength, flexibility and athletic injuries. Sports Med. 1992;14(5):277-288.

5. Maffulli N, King JB, Helms P. Training in elite young athletes (the Training of Young Athletes (TOYA) Study): injuries, flexibility and isometric strength. Br J Sports Med. 1994;28(2):123-136.

6. Nelson JK, Johnson BL, Smith GC. Physical characteristics, hip flexibility and arm strength of female gymnasts classified by intensity of training across age. J Sports Med Phys Fitness. 1983;23(1):95-101.

7. Delas S, Babin J, Katic R. Effects of biomotor structures on performance of competitive gymnastics elements in elementary school female sixth-graders. Coll Antropol. 2007;31(4):979-985.

8. Delas S, Zagorac N, Katic R. Effects of biomotor structures on performance of competitive gymnastics elements in elementary school male sixth-graders. Coll Antropol. 2008;32(2):443-449.

9. Bradshaw E. Target-directed running in gymnastics: a preliminary exploration of vaulting. Sports Biomech. 2004;3(1):125-144.

10. Lindner KJ, Caine DJ, Johns DP. Withdrawal predictors among physical and performance characteristics of female competitive gymnasts. J Sports Sci. 1991;9(3):259-272.

11. Sands B, Caine DJ, Borms J. Scientific aspects of women’s gymnastics. Basel ; New York: Karger; 2003.

12. Bencke J, Damsgaard R, Saekmose A, Jorgensen P, Jorgensen K, Klausen K. Anaerobic power and muscle strength characteristics of 11 years old elite and non-elite boys and girls from gymnastics, team handball, tennis and swimming. Scand J Med Sci Sports. 2002;12(3):171-178.

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13. Jemni M, Sands WA, Friemel F, Stone MH, Cooke CB. Any effect of gymnastics training on upper-body and lower-body aerobic and power components in national and international male gymnasts? J Strength Cond Res. 2006;20(4):899-907.

26. Regnier G, Salmela HH. Predictors of Success in Canadian Male Gymnasts. In: Petiot B, Salmela JH, Hoshizaki TB, eds. World Indentification Systems for Gymnastic Talent. Montreal: Sports Psyche Editions; 1987.

14. Bradshaw EJ, Le Rossignol P. Anthropometric and biomechanical field measures of floor and vault ability in 8 to 14 year old talent-selected gymnasts.

Sports Biomech. 2004;3(2):249-262.

27. Alves CR, Borelli MT, Paineli Vde S, et al.

Development of a specific anaerobic field test for aerobic gymnastics. PloS one. 2015;10(4):e0123115.

15. Faria IE, Faria EW. Relationship of the anthropometric and physical characteristics of male junior gymnasts to performance. J Sports Med Phys Fitness. 1989;29(4):369-378.

16. Daly RM, Bass SL, Finch CF. Balancing the risk of injury to gymnasts: how effective are the counter measures? Br J Sports Med. 2001;35(1):8-18; quiz 19.

17. Lindner K, Caine D. Injury predictors among female gymnasts’anthropometric and performance characteristics. In: Hermans G, Mosterd W, eds.

Sports, Medicine and Health. Amsterdam: Excerpta Medica; 1990:136–141.

18. Peltenburg AL, Erich WB, Bernink MJ, Huisveld IA. Selection of talented female gymnasts, aged 8 to 11, on the basis of motor abilities with special reference to balance: a retrospective study. Int J Sports Med. 1982;3(1):37-42.

19. Sands WA. Injury prevention in women’s gymnastics. Sports Med. 2000;30(5):359-373.

20. Bajin B. Talent Identification Program for Canadian Female Gymnasts. In: Petiot B, Salmela JH, Hoshizaki TB, eds. World Indentification Systems for Gymnastic Talent. Montreal: Sports Psyche Editions; 1987.

21. Grabinar MD, McKelvain R. Implementation of a Profiling/Prediction Test Battery in the Screening of Elite Men Gymnasts. In: Petiot B, Salmela JH, Hoshizaki TB, eds. World Indentification Systems for Gymnastic Talent. Montreal: Sports Psyche Editions; 1987.

22. Ho R. Talent Indentification in China. In: Petiot B, Salmela JH, Hoshizaki TB, eds. World Indentification Systems for Gymnastic Talent. Montreal: Sports Psyche Editions; 1987.

23. Sands WA. Olympic Preporation Camps 2000 Physical Ability Testing. Technique. 2000;20(10):6-19.

24. Sleeper M, Kenyon L, Casey E. Measuring Fitness in Female Gymnasts: The Gymnastics Functional Measurement Tool. International Journal of Sports Physical Therapy. 2012;7(2):124-138.

25. USA-Gymnastics. Men’s Future Stars Program Overview. 2009; https://usagym.org/PDFs/Men/ Future Stars/FutureStarsRoutines.pdf. Accessed January 8, 2015.

28. Uljevic O, Esco MR, Sekulic D. Reliability, validity, and applicability of isolated and combined sportspecific tests of conditioning capacities in top-level junior water polo athletes. J Strength Cond Res. 2014;28(6):1595-1605.

29. Uljevic O, Spasic M, Sekulic D. Sport-specific motor fitness tests in water polo: reliability, validity and playing position differences. Journal of sports science & medicine. 2013;12(4):646-654.

30. Keogh JW, Weber CL, Dalton CT. Evaluation of anthropometric, physiological, and skill-related tests for talent identification in female field hockey. Can J Appl Physiol. 2003;28(3):397-409.

31. Mohamed H, Vaeyens R, Matthys S, et al.

Anthropometric and performance measures for the development of a talent detection and identification model in youth handball. J Sports Sci. 2009;27(3):257266.

32. Pearson DT, Naughton GA, Torode M. Predictability of physiological testing and the role of maturation in talent identification for adolescent team sports. J Sci Med Sport. 2006;9(4):277-287.

33. Reilly T, Williams AM, Nevill A, Franks A. A multidisciplinary approach to talent identification in soccer. J Sports Sci. 2000;18(9):695-702.

34. Williams AM, Reilly T. Talent identification and development in soccer. J Sports Sci. 2000;18(9):657667.

35. Myers BA, Jenkins WL, Killian C, Rundquist P. Normative data for hop tests in high school and collegiate basketball and soccer players. Int J Sports Phys Ther. 2014;9(5):596-603.

36. Schaal M, Ransdell LB, Simonson SR, Gao Y. Physiologic performance test differences in female volleyball athletes by competition level and player position. J Strength Cond Res. 2013;27(7):1841-1850.

37. Lockie R, Schultz A, Callaghan S, Jordan C, Luczo T, Jeffriess M. A preliminary investigation into the relationship between functional movement screen scores and athletic physical performance in female team sport athletes. Biology of sport. 2015;32(1):41-51.

38. Bardenett SM, Micca JJ, DeNoyelles JT, Miller SD, Jenk DT, Brooks GS. Functional Movement Screen Normative Values and Validity in High School

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39.

40.

41.

42.

43.

Athletes: Can the Fms Be Used as a Predictor of Injury? Int J Sports Phys Ther. 2015;10(3):303-308.

Sleeper MD, Kenyon LK, Casey E. Measuring fitness in female gymnasts: the gymnastics functional measurement tool. Int J Sports Phys Ther.

2012;7(2):124-138.

Sleeper M, Beers M, Erwin M, et al. The Gymnastics Functional Measurement Tool: An Instrument for the Physical Assessment of Competitive Gymnasts.

Paper presented at: American College of Sports Medicine2006; Denver, CO. Sleeper M, Casey E. The Gymnastics Functional Measurement Tool: A Valid way of Measuring Gymnastics Physical Abilities. Paper presented at: American Physical Therapy Association Combined Sections Meeting2010; San Diego, CA. Portney L, Watkins M. Foundations of Clinical Research: Applications to Practice. third ed. Upper Saddle River, NJ: Pearson/Prentice Hall; 2009.

Cicchetti DV. The precision of reliability and validity estimates re-visited: distinguishing between clinical and statistical significance of sample size

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requirements. Journal of clinical and experimental neuropsychology. 2001;23(5):695-700.

Mirandola M, Bisoffi G, Bonizzato P, Amaddeo F. Collecting psychiatric resources utilisation data to calculate costs of care: a comparison between a service receipt interview and a case register. Social psychiatry and psychiatric epidemiology.

1999;34(10):541-547.

Caine D, Knutzen K, Howe W, et al. A three-year epidemiological study of injuries affecting young female gymnasts. Phys Therap Sport. 2003;4:10-23.

Dixon M, Fricker P. Injuries to elite gymnasts over 10 yr. Med Sci Sports Exerc. 1993;25(12):1322-1329.

Kerr G. Injuries in Artistic Gymnastics. J Cdn Athlet Therap Assoc. 1991(April):19-21.

Sechrest L. Validity of measures is no simple matter.

Health Serv Res. 2005;40(5 Pt 2):1584-1604.

49. Caine D, Cochrane B, Caine C, Zemper E. An epidemiologic investigation of injuries affecting young competitive female gymnasts. Am J Sports Med. 1989;17(6):811-820.

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APPENDIX I. Instructions for Administration of the MGFMT

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APPENDIX I. Instructions for Administration of the MGFMT (continued)

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APPENDIX I. Instructions for Administration of the MGFMT (continued)

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APPENDIX I. Instructions for Administration of the MGFMT (continued)

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APPENDIX I. Instructions for Administration of the MGFMT (continued)

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APPENDIX II. Menâ&#x20AC;&#x2122;s Gymnastics Functional Measurement Tool (MGFMT)

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APPENDIX II. Menâ&#x20AC;&#x2122;s Gymnastics Functional Measurement Tool (MGFMT) (continued)

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APPENDIX II. Menâ&#x20AC;&#x2122;s Gymnastics Functional Measurement Tool (MGFMT) (continued)

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IJSPT

ORIGINAL RESEARCH

THE RELIABILITY OF FABER TEST HIP RANGE OF MOTION MEASUREMENTS Jennifer J Bagwell, PT, PhD, DPT1 Lauren Bauer, BS1 Marissa Gradoz, BA1 Terry L Grindstaff, PT, PhD, ATC, SCS1

ABSTRACT Background: The Flexion ABduction External Rotation (FABER) test is typically used as a provocation special test, but has also been used as a measurement of combined hip range of motion (ROM). It is thought that limited ROM with this measurement may be indicative of hip pathology. To date, normative data, reliability, and minimal detectable change (MDC) of such measurements have not been established.

Purpose: To determine normative FABER height, assess inter- and intra-rater reliability and MDC for FABER, and compare traditional FABER measurements to methods which account for differences in thigh length.

Study Design: Descriptive laboratory reliability study Methods: Nineteen healthy participants without low back, hip, or knee pain in the preceding three months were recruited. Measurements were performed during two sessions (three to seven days between sessions) by three clinicians. FABER height and thigh length measurements were performed. Thigh length normalized FABER range of motion (ROM) and side-to-side FABER ROM symmetry were calculated. One tester also measured FABER with a digital inclinometer. Inter- and intra-rater reliability were calculated using interclass correlation coefficients (ICC) and mean MDC values were calculated.

Results: Mean values for FABER height and normalized FABER ROM were 12.4 + 2.8 cm and 0.30 + 0.07, respectively. Inter-rater reliability for FABER and normalized FABER were good (ICC 0.67-0.68) and between session intrarater reliability were good to excellent (ICC 0.76-0.86). Mean FABER and normalized FABER ROM MDC were 3.7 cm and 0.04, respectively. Mean FABER ROM symmetry was 2.0 + 0.9 cm with poor inter-rater reliability (ICC 0.20), poor to good intra-rater reliability (ICC 0.38-0.66), and mean MDC of 4.0 cm. FABER measured with a ruler, normalized FABER ROM, and inclinometry all resulted in excellent intra-rater reliability, with the highest ICC being demonstrated for inclinometry (ICC 0.86, 0.86, and 0.91).

Conclusions: Overall, FABER measurements were reliable, whether normalized to thigh length or not. Furthermore, use of inclinometry may increase reliability. Reliability was poor to good when assessing symmetry between limbs.

Level of evidence: Level 3 Key words: FABER, femoroacetabular impingement, hip, range of motion, reliability

1

Department of Physical Therapy, Creighton University, Omaha, NE, USA

CORRESPONDING AUTHOR Jennifer J Bagwell Department of Physical Therapy, Creighton University 2500 California Plaza Omaha, NE 68114, USA 402-280-5188 E-mail: jennybagwell@creighton.edu

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INTRODUCTION The Flexion Abduction External Rotation (FABER) test is commonly utilized as a provocation test to detect hip, lumbar spine, or sacroiliac joint pathology.1 Several authors have reported the utility and reliability of FABER as a provocation test for the hip.2-6 They have also indicated that assessment of pain with FABER may be a useful addition to a comprehensive hip examination, particularly for anterior hip or groin pain.7 The FABER test has also been suggested to have clinical utility as an assessment of multi-directional hip range of motion (ROM),7-12 though research is lacking regarding the use of FABER for this purpose.

FABER ROM (height of the lateral femoral epicondyle) has been suggested to be indicative of capsular tightness,7 psoas muscle spasm,7 or posterior abutment of the femur in the acetabulum.13 The method utilized to quantify FABER ROM is to measure the perpendicular distance from the table to the lateral femoral epicondyle.7-12 In particular, it has been suggested that between limb asymmetry in FABER height may indicate potential femoroacetabular impingement (FAI) or hip pathology on the side of reduced range of motion.7,9-11 Specifically, a cut-off of 3-4 cm of asymmetry between limbs has been suggested as a possible indication of FAI.10,11 While clinical experts report the utility of FABER height,7-11 the only study, to date, which has reported FABER height measurements utilized a population of professional golfers.12 Normative values in a general population and normative side-to-side symmetry values remain unknown. Additionally, the reliability and minimal detectable change (MDC) of these measurements have not been established. Lastly, FABER height would be expected to vary with thigh length; therefore, it may be necessary to normalize FABER height to thigh length or to utilize a measurement without this limitation, such as the use of an inclinometer. Therefore, the purposes of this study were 1) to establish normative values, inter-and intra-rater reliability, and MDC values for FABER height, normalized FABER ROM, and FABER ROM symmetry and 2) to compare intra-rater reliability and MDC values of FABER measured via a ruler, normalized FABER ROM, and FABER measured via inclinometry.

METHODS Participants Nineteen participants (11 female, 8 male; age 23.5 + 1.2; height 173.2 + 8.6 cm; mass 69.2 + 13.4 kg) were recruited from an academic setting. Participants were excluded if they reported hip, knee, low back, or sacroiliac pain within the preceding three months or if they had any history of hip or low back surgery. All participants signed the University IRB approved informed consent form.

Procedures Three testers performed measurements during two separate testing sessions (three to seven days between sessions). Tester 1 (JJB) was a physical therapist with 10 years of experience and Testers 2 and 3 (MG, LB) were first year physical therapy students. The novice testers underwent approximately two hours of training with the experienced tester in order to standardize procedures and practiced these procedures on five volunteers prior to the study.

Participants were all tested in the same order (Tester 1, 2, and then 3) with the right limb assessed prior to the left by each tester.

Passive FABER range of motion was measured with the participant in the supine Figure 4 position (Figure 1A). The tester stabilized the contralateral ASIS and applied overpressure to the ipsilateral medial knee in the direction of the table while measuring the perpendicular distance from the lateral femoral epicondyle to the table using a ruler (Figure 1A).

Tester 1 repeated the FABER measurement using a digital inclinometer placed with the distal end at the medial epicondyle (Figure 1B). This position on the femur was selected for inclinometer placement in order to be consistent with the landmark utilized for the ruler measurement. Next, all testers measured thigh length between the greater trochanter and the lateral epicondyle of the femur.

Data analysis and statistical methods The primary outcomes included FABER height (cm), normalized FABER ROM, FABER ROM symmetry (cm), FABER ROM with an inclinometer (degrees), and FABER ROM symmetry with an inclinometer (degrees). Normalized FABER ROM was calculated as the FABER ruler height divided by thigh length.

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used to compare normative values by sex. Interand intra-rater reliability were calculated for FABER height, normalized FABER ROM, and FABER ROM symmetry. Additionally, for Tester 1, between session intra-rater reliability was calculated for FABER measured with an inclinometer and FABER ROM symmetry measured with an inclinometer.

All reliability analyses were conducted in SPSS (version 23) using interclass correlation coefficients (ICC (2,1)). The qualitative cut-offs for ICC values suggested by Cicchetti (1994)14 were utilized (poor: ICC < 0.40, fair: ICC 0.40-0.59, good: 0.60-0.74, and excellent: ICC 0.75-1.0). Mean MDC was also calculated (standard error of the measure*1.96*√2) across all testers for all variables assessed.

Figure 1. (A) (Top) FABER ruler measurement testing position. The tester stabilized the contralateral ASIS and applied overpressure to the ipsilateral medial knee in the direction of the table while measuring the perpendicular distance from the lateral femoral epicondyle to the table using a ruler. (B) (Bottom): FABER inclinometer measurement testing position with the digital inclinometer placed with the distal end at the medial epicondyle.

FABER ROM symmetry was calculated as the absolute value of right minus left FABER ruler measurements.

With the exception of the symmetry measurements, outcomes were reported as the average of the values for the right and left limbs. Independent t-tests were

RESULTS Mean FABER height and normalized FABER ROM were 12.4 + 2.8 cm and 0.30 + 0.07, respectively (Table 1). Inter-rater reliability for FABER height and normalized FABER height were good (ICC 0.67-0.68) and between session intra-rater reliability were good to excellent (ICC 0.76-0.86) (Table 1). FABER height and normalized FABER mean MDC across the three testers were 3.7 cm and 0.04, respectively (Table 1).

Mean inter-limb FABER height difference was 2.0 + 0.9 cm with poor inter-rater reliability (ICC 0.20), poor to good intra-rater reliability (ICC 0.38-0.66), and a mean MDC of 4.0 cm (Table 1).

For Tester 1, FABER with an inclinometer also demonstrated excellent intra-rater reliability (ICC 0.91).

However, intra-rater reliability for FABER ROM symmetry using an inclinometer was only fair (ICC

Table 1. FABER Measurement Reliability and Minimal Detectible Change Measurements Mean + Standard Deviation

Interrater ICC

12.4 + 2.8 cm 0.68 FABER Height Thigh Length 0.30 + 0.07 0.67 Normalized FABER ROM 2.0 + 0.9 cm 0.20 FABER ROM Symmetry FABER with NA 15.0 + 7.6° Inclinometer FABER ROM Symmetry NA 3.9 + 3.6° with Inclinometer ICC: Intraclass Correlation Coefficient FABER: Flexion ABduction External Rotation ROM: Range of Motion

Rater 1 Intrarater ICC

Rater 2 Intrarater ICC

Rater 3 Intrarater ICC

0.86

0.76

0.84

Mean Minimal Detectable Change 3.7 cm

0.86

0.76

0.85

0.04

0.66

0.51

0.38

4.0 cm

0.91

NA

NA

6.1°

0.49

NA

NA

7.9°

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Table 2. Sex Differences in FABER Measurements FABER Height

Female Male

Mean + Standard Deviation p-value 12.5 + 3.1 cm 0.65 12.2 + 2.6 cm

Thigh Length Female 0.12 + 0.03 Normalized 0.12 + 0.03 Male FABER ROM Female 1.9 + 0.9 cm FABER ROM 2.2 + 0.9 cm Male Symmetry Female 15.4 + 8.6° FABER with Male 14.5 + 7.0° Inclinometer FABER ROM Female 4.5 + 4.5° Symmetry with Male 2.9 + 1.5° Inclinometer FABER: Flexion ABduction External Rotation

0.49). With the inclinometer, the MDC for FABER and FABER ROM symmetry were 6.1° and 7.9°, respectively (Table 1). With respect to sex, the authors found no significant differences in any FABER measurement (p=0.33-0.73) (Table 2). Due to the relatively small sample size when comparing sex differences, Hedges’ g effect sizes were calculated and were small to moderate (0.17-0.47) (Table 2).

DISCUSSION Expert clinicians have promoted the incorporation of FABER height measurements in a comprehensive hip examination 7,9-11 and FABER range of motion impairments may exist in persons with FAI. 15 However, to date, normative values for FABER height have not been reported in the general population.

A single study 12 of professional golfers found mean FABER height values in the lead and non-lead hip to be 9.3 + 1.5 cm and 6.8 + 1.2 cm, respectively. Participants in the current study demonstrated slightly larger mean FABER heights (12.4 + 2.8 cm). These differences may be due to the different populations assessed (male professional golfers verses collegiate age males and females) or possible differences in measurement technique, as the authors of the previous study did not specify stabilization procedures or use of overpressure. In the current study, FABER height was not significantly different between males and females (p=0.65) and this effect size was small (0.23), indicating minimal differences.

This was the first study to assess reliability of FABER height and to consider FABER ROM normalized to thigh length. The findings of the current study indicate that among both experienced and novice testers,

Effect Size 0.23

0.64

0.26

0.39

0.41

0.73

0.17

0.33

0.47

FABER height and normalized FABER ROM values have excellent intra-rater reliability and good interrater reliability. Furthermore, mean MDC values for FABER height and normalized FABER ROM of 3.7 cm and 0.04 indicate the smallest changes that can be detected beyond measurement error. Reliability and MDC values were assessed in both experienced and novice practitioners, which may have deflated interrater reliability values compared to inclusion of only experienced clinicians, but likely increased the external validity of the findings.

FABER range of motion was also quantified by Tester 1 using a digital inclinometer. FABER measured with a ruler, normalized FABER ROM, and FABER measured with a digital inclinometer all resulted in excellent intra-rater reliability (ICC 0.86, 0.86, and 0.91, respectively), with the best reliability for inclinometry. MDC scores indicate that a 6.1° change in FABER measured with an inclinometer is necessary to detect change beyond measure error. Clinicians may consider use of an inclinometer to quickly and reliably measure FABER. Because the FABER ruler measurement is in reference to the femur, the inclinometer was placed on the femur in the current study; however, the tibia has less soft tissue and future research should evaluate placement along the medial tibia. Additionally, it should be noted that inter-rater reliability and intra-rater reliability for novice examiners using a digital inclinometer were not assessed in the current study.

Regardless of method of assessment (measured with a ruler or inclinometer), FABER ROM symmetry demonstrated poor to good reliabilities. Reliabil-

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ity may have been lower for symmetry due to the use of multiple measurements (both left and right limb), which may have increased the opportunity for errors. For FABER ROM symmetry, the normative difference was 2.0 + 0.9 cm and the mean MDC was 4.0 cm, indicating that a large relative change would be necessary to detect any differences beyond measurement error. A 3-4 cm between limb asymmetry has been suggested as a possible indication of FAI. 10,11 It should be noted that the ICC and MDC values may be different in a population with hip pathology where greater asymmetry between the involved and uninvolved limbs may occur. Therefore, while these findings indicate that caution should be utilized when interpreting differences in FABER ROM symmetry, future research should investigate FABER values and reliability in a population with hip pathology.

CONCLUSIONS Overall, FABER height measurements could be obtained with good reliability, whether normalized to thigh length or not. Furthermore, results indicate that use of an inclinometer may increase reliability when performed by an experienced clinician.

However, caution should be utilized when assessing inter-limb differences in FABER. More research is necessary to determine if FABER asymmetry is a valid assessment of potential hip pathology, as has been suggested clinically.

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2. Martin RL, Sekiya JK. The interrater reliability of 4 clinical tests used to assess individuals with musculoskeletal hip pain. J Orthop Sports Phys Ther.

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3. Maslowski E, Sullivan W, Forster Harwood J, et al.

The diagnostic validity of hip provocation maneuvers to detect intra-articular hip pathology.

PM R. 2010;2(3):174-181.

4. Troelsen A, Mechlenburg I, Gelineck J, et al. What is the role of clinical tests and ultrasound in acetabular labral tear diagnostics? Acta Orthop. 2009;80(3):314-318.

5. Ratzlaff C, Simatovic J, Wong H, et al. Reliability of hip examination tests for femoroacetabular impingement. Arthritis Care Res. 2013;65(10):16901696.

6. Mitchell B, McCrory P, Brukner P, et al. Hip joint pathology: clinical presentation and correlation between magnetic resonance arthrography, ultrasound, and arthroscopic findings in 25 consecutive cases. Clin J Sport Med. 2003;13(3):152-156.

7. Martin RL, Enseki KR, Draovitch P, et al. Acetabular labral tears of the hip: examination and diagnostic challenges. J Orthop Sports Phys Ther. 2006;36(7):503515.

8. Philippon MJ, Maxwell RB, Johnston TL, et al.

Clinical presentation of femoroacetabular impingement. Knee Surg Sports Traumatol Arthrosc.

2007;15(8):1041-1047.

9. Philippon MJ, Weiss DR, Kuppersmith DA, et al.

Arthroscopic labral repair and treatment of femoroacetabular impingement in professional hockey players. Am J Sports Med. 2010;38(1):99-104.

10. Philippon MJ, Ho CP, Briggs KK, et al. Prevalence of increased alpha angles as a measure of cam-type femoroacetabular impingement in youth ice hockey players. Am J Sports Med. 2013;41(6):1357-1362.

11. Philippon MJ, Patterson DC, Briggs KK. Hip arthroscopy and femoroacetabular impingement in the pediatric patient. J Pediatr Orthop. 2013;33 Suppl 1:S126-130.

12. Vad VB, Bhat AL, Basrai D, et al. Low back pain in professional golfers: the role of associated hip and low back range-of-motion deficits. Am J Sports Med. 2004;32(2):494-497.

13. Kapron AL, Aoki SK, Peters CL, et al. Accuracy and feasibility of dual fluoroscopy and model-based tracking to quantify in vivo hip kinematics during clinical exams. J Appl Biomech. 2014;30(3):461-470.

14. Cicchetti D. Guidelines, criteria, and rules of thumb for evaluating normed and standardized assessment instruments in psychology. Psychological Assessment.

1994;6(4):284-290.

15. Kapron AL, Aoki SK, Peters CL, et al. In-vivo hip arthrokinematics during supine clinical exams: Application to the study of femoroacetabular impingement. J Biomech. 2015;48(11):2879-2886.

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IJSPT

CASE SERIES

MODIFYING MARCHING TECHNIQUE IN MILITARY SERVICE MEMBERS WITH CHRONIC EXERTIONAL COMPARTMENT SYNDROME: A CASE SERIES Pieter H. Helmhout, PhD, MSc1 MAJ Angela Diebal-Lee, PT, DSc2 Laurens R. Poelsma, BSc3 Chris C. Harts, MSc1 LTC Wes O. Zimmermann, MD, Fecsm1

ABSTRACT Background and Purpose: The long-term effectiveness of both operative and non-operative management approaches for Chronic Exertional Compartment Syndrome of the lower legs (CECS) is moderate at best. Positive outcomes have recently been reported on modifying running technique in individuals with CECS. The purpose of this case series was to evaluate a training program aimed at changing marching technique in individuals with CECS, based on principles that aim to eliminate heel strike and decrease impact during foot strike.

Study Design: Case series.

Methods: Six service members with CECS underwent a five-week training program aimed at modifying marching technique. The program was comprised of foot/lower leg strengthening exercises, perception drills, and treadmill/ outdoor marching bouts. Self-assessed leg condition, march endurance performance, and kinematic/kinetic measurements were assessed at baseline (T0), post-treatment (T5), and nine months post-intervention (T40).

Results: Moderate to fair pre- to post improvements on the self-assessed leg condition outcomes were demonstrated for most participants (4% to 73% improvements). These scores continued to improve until the 9 months follow-up.

Marching performance improved during the intervention period in all but one subject, ranging from 6% to 38% improvement in marching time. Kinematic and kinetic data showed pre- to post-intervention changes that were reflective of the marching technique modification in most subjects. Post-intervention pain profiles of participants during marching showed that, in most subjects, the onset of leg pain was delayed compared to baseline.

Conclusions: A five-week intervention aimed at altering marching technique has demonstrated moderately promising results in a group of service members with CECS of the lower legs who had previously undergone other conservative management interventions without success. Due to the relatively small sample size and the variability in subject outcomes, further research is warranted.

Key Words: Chronic exertional compartment syndrome, lower leg, marching technique Level of Evidence: 4

1

Department of Training Medicine and Training Physiology / Military Sports Medical Center Personnel Command, Royal Netherlands Army, Utrecht, The Netherlands 2 Program Director, Physical Therapist Assistant Program, Fort Sam Houston, San Antonio, TX, USA 3 Leiden University Medical Centre, Leiden, The Netherlands

CORRESPONDING AUTHOR Pieter Helmhout Department of Training Medicine and Training Physiology / Military Sports Medical Center Personnel Command, Royal Netherlands Army PO Box 90004, 3509 AA Utrecht, The Netherlands E-mail: ph.helmhout.01@mindef.nl Tel: +31-30-2181991, Mob: +-31-6-83649699

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INTRODUCTION Lower extremity overuse injuries are a widespread problem in the military, commonly occurring in new recruits and infantry soldiers.1 Physical training and sports related activities account for up to 90% of all injuries and 80% of those injuries are considered overuse in nature.2,3,4 One of the overuse injuries consistent with the military lifestyle is chronic exertional compartment syndrome (CECS).5 This condition is classically prevalent with activities such as running and marching while carrying a load.6 CECS is an obstinate and theoretically multi-factorial musculoskeletal injury.4,7 The classic symptom of CECS is a complaint of increasing lower leg pain during physical exertion, cramping, burning or aching in nature, and often leading to premature cessation of activity.7 Neurological symptoms, such as numbness or muscle weakness in the lower legs, are only present in some cases and vary depending on which nerve is involved.8 Physical signs and symptoms at rest are often absent. Amateur athletes who are hampered in their training activities by CECS often modify, decrease, or even stop these activities in an effort to avoid CECS symptoms.4,9 Unfortunately, the military operational tempo does not allow for significant modifications of training activities. Eventually, this may lead to chronicity of the problem and eventual attrition from military duty.

The long-term effectiveness of conservative treatment interventions such as orthotics, massage, and stretching remains less than optimal.10,11,12 Surgical management by means of a fasciotomy, in which the fascia is cut to relieve Intra-Compartmental Pressure (ICP), has proven to be a somewhat effective treatment approach in CECS management.11,13 However, up to 17% of subjects undergoing fasciotomy experience less than favorable outcomes, such as decreased sensation or hypersensitivity over the incision site, numbness at the lateral lower leg, ankle pain, and reoccurrence of symptoms.10,14,15 Moreover, there are risks and complications associated with surgery, such as hemorrhage, infection, or nerve damage, and a significant hiatus from activity; not to mention the burden that postoperative rehabilitation has on military readiness.8,15 The prognosis, in terms of returning to an adequate level of military infantry readiness, is moderate at best.16,17 This gives reason

to further investigate effective conservative management approaches.

As an alternative to surgical interventions, Diebal et al10,18 have recently reported positive outcomes in U.S. military members diagnosed with CECS by modifying their running technique. A six-week training program was used to implement a forefoot running technique in order to eliminate heel strike and have the foot contact the ground as close to under the general center of mass as possible. This program led to decreased post-exercise ICP values, significant reductions in pain and disability, and improved performance outcomes on run tests. More importantly, surgical intervention was avoided for all subjects at the one-year follow-up. If a modification of running technique shows therapeutic benefits for subjects with CECS, potentially a modification of marching/ walking technique could elicit the same results. This may be relevant for civilian athletes participating in long distance walking events who also suffer from fatigue-related overuse leg injuries.19,20 The rationale for this type of intervention is that most runners have a habitual heel strike pattern, with a long stride length, slow cadence, and an excessive dorsiflexion of the ankle at ground contact. This places the runner in a position of terminal knee extension and ankle dorsiflexion at landing, which results in marked increased eccentric activity of the anterior compartment muscles of the lower leg, in particular the tibialis anterior muscle.

Ultimately, the combination of knee extension and ankle dorsiflexion may lead to CECS symptoms in repetitive movements such as running.21 In order to eliminate the terminal knee extension and ankle dorsiflexion position at heel contact, a forefoot running technique is suggested. This method focuses on changing running style from a heel strike pattern toward a forefoot strike pattern (i.e., landing on the ball of foot), by performing various drills and exercises to get the runner to contact the ground with the foot as close to under the center of mass as possible. Instructions include decreasing stride length by increasing cadence (to 180 steps per minute) and pulling the foot from the ground with the hamstring muscles, thereby eliminating push off with the gastroc-soleus muscles. These adaptations have been shown to decrease weight acceptance rates,

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minimize ground contact time and vertical displacement, and eliminate the rearfoot strike that causes the eccentric loading of the anterior compartment musculature of the lower leg.10,22,23,24,25 Following the studies by Diebal et al,10,18 a series of case reports have been conducted to evaluate the effectiveness of the forefoot running intervention strategy in Dutch service members with CECS.25 In 19 subjects, a 6-week forefoot running intervention performed in both center-based and home-based training settings led to decreased post-running lower leg ICP values and improved run performance (distance). The pain and disability typically associated with CECS were significantly reduced.

Unfortunately, a substantial subset of recruits and infantry soldiers with CECS report that their lower leg complaints are caused and prolonged by (forced) marching activities, as opposed to running activities. In an effort to resolve this dilemma, a five-week training program was constructed aimed at changing marching technique, while integrating movement principles derived from a forefoot running technique. The purpose of this study was to evaluate a training program based on principles that aim to eliminate heel strike and decrease impact during foot strike aimed at changing marching technique in military service members with CECS. METHODS Subjects From January to April 2014, military service members from the Royal Netherlands Army, diagnosed with CECS by a general surgeon of the Central Military Hospital in Utrecht, The Netherlands, were sent to the Military Sports Medical Center in Utrecht to be assessed for inclusion. To be included in this study, subjects had to report a two-month history of recurrent anterior and/or lateral leg pain and tightness in one or both legs that was exacerbated with marching activities. Pain had to occur in the first 15 minutes of marching and had to lead to the termination of the marching activity. In addition, all symptoms had to completely resolve within 15 minutes after the cessation of marching activity. The physical examination findings had to be normal at rest (i.e., full ankle and knee range of motion and strength and full func-

tional ability to squat and hop without symptoms).

Finally, the intracompartmental pressure at one minute after a standardized exercise protocol had to be above 35 mmHg in at least one anterior compartment. Exclusion criteria included: a history of previous fasciotomy or other lower extremity surgery, any condition that would cause lower extremity swelling, creatine supplementation in the previous two months, any injury that would affect marching tolerance besides CECS, a current use of nonsteroidal anti-inflammatory drugs (NSAIDâ&#x20AC;&#x2122;s) that would interfere with test outcomes, and co-interventions such as other exercise therapy modalities in the two weeks preceding the baseline measurements through the post-intervention measurements of this study. Each participant was given a verbal and written explanation of the study protocol and provided informed consent prior to testing.

Pre-Intervention Measurements (T0) Intracompartmental Pressure Measurements and Biometry To objectify and confirm the clinical diagnosis of CECS, one-minute post-exercise ICPs of the anterior compartments were measured, following a standardized treadmill run test protocol as described by Zimmermann et al.27 Baseline measurements included biometric parameters: body height, body weight, fat percentage (skinfold measurement28), waist circumference, and blood pressure. Measurements were performed by the same (experienced) practitioner to avoid inter-rater reliability issues.

Self-assessed Leg Condition and Physical Activity.

Participants filled out the following self-report questionnaires: â&#x20AC;˘

The Single Assessment Numeric Evaluation (SANE),10 a one-item question rating the lower leg condition on a 0-100 scale, with 100 being normal.

â&#x20AC;˘

The Lower Leg Outcome Survey (LLOS),10 a 20-item scale questionnaire that specifically evaluates leg conditions such as CECS, with a range of scores between 0-60, a score of 60 being normal.

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â&#x20AC;˘

The Subject Specific Complaints (PSC) questionnaire,29 in which, from a list of different daily activities, subjects had to select the one to three most important activities that were hampered by their leg complaints in the past week, and rate them on a 100 mm visual analogue scale (VAS).

â&#x20AC;˘

The validated Short Questionnaire to Assess Health Enhancing Physical Activity (SQUASH),30 measuring the degree of daily physical activity (subdivided into following categories: commuting activities, work activities, household activities, leisure time activities, and sports activities), and expressed as activity scores per week.

Marching Performance and Kinematic/Kinetic Measurements Approximately one week after the ICP measurements were taken in the hospital, participants performed a baseline marching test on an instrumented treadmill (Zebris FDM-T, GmbH, Isny im Allgäu; calibrated in January 2014) at the Sports Medical Center. During the test, participants wore shorts, a t-shirt, military boots, and carried a backpack containing 21 kg of total weight. After a five-minute treadmill warm-up without a backpack at 4.5 km/h, participants started marching at 5.0 km/h. Treadmill speed was increased every 10 minutes by 0.5km/h for up to 60 minutes of marching. Kinematic data (i.e., step length, cadence, time of load change from heel to forefoot during the stance phase) and kinetic data (i.e., maximum force in heel area) were collected for one minute in the second minute of each stage; data from the last complete stage was reported.

Verbal pain scores on a 0-10 scale were gathered at the end of each minute during the whole marching test. The test was aborted when participants reached 60 minutes of marching, when they reported a pain score of seven or more (out of 10) in at least one of four lower leg regions (anteriomedial, anteriolateral, posteriomedial, and posteriolateral), or when they asked to stop due to reaching their cardiorespiratory limit. Verbal pain scores were also asked at one, five, and 10 minutes following marching cessation.

Intervention Immediately after informed consent was obtained, two weeks preceding the first training session, participants were instructed on core stability and

strengthening exercises for the feet and lower legs.

These exercises were used to prepare the lower body for the new marching technique. A training schedule and log was utilized to increase subject compliance with performing these exercises at home on a daily basis prior to the initiation of the marching program. Participants were instructed to continue these exercises every other day throughout the fiveweek training period. Prior to the first marching session, a physical therapist examined all participants to ensure that all physical findings were still within normal limits before starting the marching activities. The first training session was also used to provide a detailed rationale to the subject regarding the concepts used in the intervention program.

After these preliminary events, a five-week training program aimed at altering marching technique was provided by a team of specialists, which included a physical therapist, a human movement scientist, and a medical student. The aims of the marching program were to train the participants to march with a higher cadence, shorter strides, and relaxed foot and lower leg muscles, in order to decrease the work load of the anterior compartment musculature when marching. Appendices 1 to 5 present the intervention protocol and typical examples of the exercises and drills used in this study.

Five weeks of training was chosen as the optimal intervention length, based on previous experiences within the sports medical center with treating lower leg subjects using marching activities [W. Zimmermann, unpublished data, 2010-2013]. The training program consisted of 11 training sessions of 90 minutes each in a five-week period. Six trainings sessions took place at the research center. For the remaining five training sessions, participants exercised at their own military base or at home, utilizing a training log that contained descriptions of each exercise as well as the training protocol.

Training sessions consisted of the following elements (Appendices 2-5): waist-down joint flexibility exercises; perception drills (focusing on issues such as perception of body weight and pressure on the ball of the foot, vertical joint alignment, and falling forward); marching bouts on the treadmill; outdoor marching bouts on track and dirt roads. Time spent

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on exercises and drills remained constant (approx.

50 minutes), whereas the intensity and the amount of time spent on marching sessions increased throughout the program (from 20 up to 35 minutes).

All training sessions were concluded with 10 minutes of regular stretching exercises for the muscles of the lower legs tailored to the needs of the subject.

For proprioceptive purposes, all exercises and drills were performed barefoot. Participants performed the first few training sessions barefoot, followed by training sessions with running shoes, military boots, and military boots with additional gear (military uniform, backpack), respectively. Both verbal and written information about how to lace up military boots was provided by an orthopedic shoe technician at the first training session. Lacing military boots too tightly, especially around the distal lower leg, may potentially obstruct blood flow and increase CECS complaints.

Besides verbal cues (e.g., “take shorter strides”, “increase step frequency”, “relax the foot”, “don’t bend at the waist”), a digital metronome (training center) or a metronome-app (home based) was used to pace the cadence at 125 to 130 steps per minute. This pace interval was based on previous experiences with treadmill marching activities in CECS subjects at the laboratory. At several training sessions, an EMG device (BTS FREEWALK, Brooklyn NY, USA) was used as a monitoring device to provide participants real-time visual feedback of the activity of their tibialis anterior muscles during marching. Additionally, throughout the training program, marching time and speed were gradually increased.

Post-intervention Measurements (T5, T40) In the fifth week, one week after the last training session, all baseline measurements (i.e., biometry, questionnaire, marching test) were repeated (T5).

The protocols were identical to those used to obtain the baseline measurements, i.e., marching tests were executed using identical speed increments and termination criteria as previously described. A Global Rating of Change (GROC)31 was also collected following the five week intervention. The GROC is a 15-point scale to measure the subjects’ perceived change and overall improvement, from ‘a very great deal worse’ (score -7) to ‘a very great deal better’ (score +7).

Nine months post-intervention (T40), participants were asked to fill in a follow-up questionnaire consisting of the SANE, LLOS, PSC, SQUASH, and GROC, as well as answer additional questions regarding (medical) treatment activities in the post-intervention period.

Statistics Descriptive analyses were used to describe possible pre- to post-differences (T0–T5 and T0–T40) in outcomes. No statistical testing was used considering the design and sample size of the study.

RESULTS Subject characteristics From February to June 2014, six male subjects were enrolled in the study: two air mobile infantry soldiers, two mounted infantry soldiers, one marine, and one signal service member. Table 1 presents baseline clinical characteristics of each included subject. Mean baseline and post-intervention values for biometry (weight, body fat, blood pressure) and level of physical activity are displayed in Table 2.

For most subjects, the onset of CECS symptoms could be traced back to basic military training and the duration of their complaints ranged from six months up to three years. Three subjects had minor symptoms of medial tibial stress syndrome (MTSS) along with their CECS complaints, although CECS was seen as the primary affliction. All subjects had already undergone several treatment modalities, ranging from rest to specific physical therapy (e.g., stretching, Shockwave therapy). None of the previous treatments were successful in diminishing their CECS complaints. Exaggerated stride lengths and a significant heel strike during marching were observed in all subjects at the baseline marching test. At baseline, only one of the six subjects succeeded in finishing the 60-minute marching test. This individual had the longest period without physical activities prior to inclusion in the study (12 weeks) compared to the other study subjects (1 to 6 weeks).

Treatment compliance The treatment period was comprised of five consecutive weeks and included six center-based training sessions and five home-based training sessions. Four

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Table 1. Baseline subject characteristics.

Table 2. Baseline (T0), 5-week post-intervention (T5), and 10-month follow-up (T40) measurements of biometry and physical activity for the six subjects. Mean values ± SD are presented.

out of six subjects fully complied with the treatment protocol. One subject performed only four of the five home-based training sessions due to operational activities, and the post-intervention measurements were delayed by one week in another subject due to a rescheduled vacation.

Pre- to post-intervention results All but one participant (Subject 5 from Table 1) showed moderate to fair improvements from preto post-intervention on the self-assessed leg condition outcome tool. Table 3 displays the overall group results: +4% to +33% for SANE, +4% to +33% for LLOS and -13% to -73% for PSC. These improve-

ments correspond to the reported post-intervention GROC scores: +3 (‘somewhat better’) in two subjects, +4 (‘moderately better) in one subject, +5 (‘quite a bit better’) in two subjects, and +6 (‘a great deal better’) in one subject. Only minor pre- to postintervention changes in biometric and blood pressure values were seen in the study group. The three subjects diagnosed with a combination of CECS and MTSS reported that they were not hindered by their MTSS symptoms during the treatment period.

Marching performance improved during the fiveweek intervention period in all but one subject (Subject 5 from Table 1), ranging from 6% to 38%

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Table 3. Baseline (T0), 5-week post-intervention (T5), and 10-month follow-up (T40) measurements of self-assessed leg condition for the six subjects. Mean values Âą SD are presented.

Table 4. Baseline (T0) and 5-week post-intervention (T5) measurements of marching performance and kinetics/kinematics for the six subjects. Kinematic and kinetic parameters are presented as averages of left and right leg of a normalized gait cyle.

increase in marching duration. Table 4 presents the mean group results across all subjects. Moreover, kinematic and kinetic data showed pre- to post-intervention changes that were reflective of the marching technique modification (i.e., shorter strides, higher cadence, decreased loading of the heel at ground contact) in all but two subjects (Subjects 1 and 5).

the post-intervention measurements compared to baseline. Subject 5 showed an earlier onset of pain for his left leg post-treatment, which may have been the result of a substantially longer rest period prior to baseline. Subject 6 did not show pre- to post- intervention differences.

Figure 1 demonstrates the lower leg pain profiles for each subject during the marching test at pre- and post-intervention measurements. In all but two subjects (Subjects 5 and 6), the onset of pain in the bilateral compartments of the lower legs was delayed at

Nine-Month Follow-up Results Due to logistical reasons, the follow-up periods varied between participants, ranging from 33 to 44 weeks (9 months on average). Each participant showed improvements in their self-reported out-

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Figure 1. Pain profiles of subjects during pre-intervention marching test (grey line) and five-week post-intervention measurement (black line). Subjects’ lateral compartment pain scores are presented, on a verbal 0-10 scale, for both lower legs. Subjects reported pain levels each minute of the test till marching cessation (cross). Subject numbers (1 to 6) correspond to those presented in Table 1.

comes at the end of the follow-up period, compared with the post-intervention measurements (Table 3). These additional improvements were consistent with the follow-up GROC scores: +1 (‘a tiny bit better’) in one subject, +5 (‘quite a bit better’) in one subject, +6 (‘a great deal better’) in two subjects, and +7 (‘a very great deal better’) in two subjects.

As shown in Table 2, the activity scores per week also showed an increase at the follow-up measurement compared to the baseline values: from 8,047 points ± 4,720 to 14,413 points ± 4,561. All subjects improved their levels of physical activity at work.

Three participants decreased the time spent on sports activities (mainly strength and conditioning training) for this reason.

score +4) underwent a fasciotomy five months and four months post-treatment, respectively, with an accompanying rehabilitation program. Without surgical release, both subjects were judged to be not enough physically assessable to continue their military career. All but Subject 6 continued using the marching principles that were taught during the study in their marching activities during follow-up; four of them used the training schedule that was issued to them at the post-treatment measurement.

One participant (Subject 4) used medication for his lower leg symptoms during the follow-up period. No participant reported other lower leg complaints during follow-up.

Results from additional questions at the follow-up measurement regarding the nine-month follow-up period showed that three participants continued exercising their legs on their own terms, one participant was trained by a physical trainer, and two participants (Subject 4 with post-treatment GROC score +5, and Subject 6 with post-treatment GROC

DISCUSSION A five-week treatment program aimed at changing marching technique was studied in a group of six Dutch military service members with CECS of the lower legs. The study hypothesis was that the marching intervention would lead to increased marching performance/tolerance and decreased pain levels

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due to reduced muscular demand in the anterior compartments of the lower legs. Although not universal, on average, small post-treatment improvements were found for the self-assessed lower leg condition outcomes, marching performance, and accompanying lower leg pain profiles. Kinematic and kinetic data showed changes that reflected the marching technique modification. The self-assessed outcomes continued to improve in all subjects in the months following the end of the intervention, during which two of them proceeded to undergo fasciotomy.

with the instruction to leave the foot in a relaxed position during the swing phase. It was observed that all participants initially had the tendency to hold their ankles in a pronounced dorsiflexed state throughout the gait cycle. The study findings indicate that short- and mid-term improvements in marching performance and self-assessed lower leg condition may occur even with relatively small and seemingly insignificant changes in kinematic parameters (4 cm mean decrease in stride length and 6 steps/min mean increase in cadence, see Table 4).

To the authorsâ&#x20AC;&#x2122; knowledge, this is the first study to focus on modification of marching technique as a potentially beneficial conservative treatment for CECS. In a comprehensive systematic review on prevention strategies for training-related injuries in military and other active populations, Bullock et al3 listed â&#x20AC;&#x153;manipulation of running stride lengthâ&#x20AC;? among the intervention strategies without sufficient evidence to recommend such an intervention. In more recent studies, promising findings have been reported regarding the reduction in joint loading at foot strike via step rate manipulation in running activities.32,33 Diebal et al10,18 have reported on the therapeutic effects of a six-week running intervention using similar principles (e.g., shortening stride length, increasing cadence) in the U.S. Army. Pain and disability typically associated with CECS were greatly reduced up to one year after intervention, avoiding fasciotomy in all subjects. These findings were largely confirmed in a similar running intervention study in Dutch service members with CECS.26

Two subjects showed relatively low compliance to marching technique modification: Subject 1 reported a slightly higher level of lower leg complaints at the post-intervention measurement, likely due to participation in snowboarding activities in the preceding week. Subject 5 entered the study after a relatively long period of rest, with no marching activities whatsoever, compared with the other participants.

His CECS symptoms gradually started to increase throughout the treatment period, which may explain both the decline in self-assessed leg condition and lower compliance to the new marching technique at the post-intervention measurement.

It is well understood that differences exist between running and marching kinetics and kinematics.

Compared to marching/walking, running is characterized by faster speeds, longer strides, and greater impact forces. The most prominent characteristic of running is the double float phase, where neither foot is in contact with the ground; thereby leaving more room for manipulating stride length and changing foot strike patterns (e.g., from rearfoot to forefoot).

A forefoot strike is virtually impossible while walking, especially at higher speeds. Nonetheless, it was noticed in this study that subject instruction on marching at an increased cadence (i.e., shorter strides) could be effective in itself in reducing the negative impact of CECS, especially when combined

The individual pain profiles suggest that this fiveweek intervention enables less development of pain while marching at progressive speeds, although it may not completely prevent the development of CECS complaints during a marching bout. Still, this delay in the onset of and progression of pain may be of value for recruits and soldiers who are subject to unit events that involve regular marching activities.

However, as shown in two of the participants, even successful modification of marching technique with regard to pain reports may not prevent a surgical release in the long run, despite a favorable post-treatment pain profile or global rating of change score.

All findings must be seen in the light of weaknesses in the study design concerning the small sample size, lack of control group, and relatively short follow-up period. This study was built around a case series, for which patients were referred by the military hospital within a limited time frame. The total number of subjects participating in this (pilot) study was limited mainly due to logistic constraints in terms of staff capacity and facilities.

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CONCLUSIONS The results of this case series indicate that a fiveweek intervention aimed at altering elements of marching technique may be beneficial in individuals with long-lasting lower leg CECS complaints who have previously undergone other conservative management interventions without success. The relatively small sample size and the variability in subject outcomes within the program, demonstrate the necessity for follow up (controlled) studies with larger cohorts of subjects.

11. Tucker AK. Chronic exertional compartment syndrome of the leg. Curr Rev Musculoskelet Med. 2010;3(1-4):32-7.

12. Farr D, Selesnick H. Chronic exertional compartment syndrome in a collegiate soccer player: A case report and literature review. Am J Orthop. 2008;37(7):374-7.

13. Scheltinga MR, Fijter MW de, Luiting, MG. Minimally invasive fasciotomy in chronic exertional compartment syndrome and fascial hernias of the anterior lower leg: Short-and long-term results. Mil Med. 2006;171(5):399-403.

1. Sharma J, Greeves JP, Byers M, et al.

Musculoskeletal injuries in British army recruits.

BMC Musculoskeletal Disord. 2015;16:106.

14. Waterman BR, Laughlin M, Kilcoyne K, et al.

Surgical treatment of chronic exertional compartment syndrome of the leg: failure rates and postoperative disability in an active subject population. J Bone Joint Surg Am. 2013;95(7):592-6.

2. Roberts A, Franklyn-Miller A. The validity of the diagnostic criteria used in chronic exertional compartment syndrome: A systematic review. Scand J Med Sci Sports. 2012;22(5):585-95.

15. Howard JL, Mohtadi NG, Wiley JP. Evaluation of outcomes in subjects following surgical treatment of chronic exertional compartment syndrome in the leg. Clin J Sports Med. 2000;10(3):176-84.

3. Bullock SH, Jones BH, Gilchrist J, et al. Prevention of physical training-related injuries: recommendations for the military and other active populations based on expedited systematic reviews.

Am J Prev Med. 2010;38(1 Suppl):S158-81.

16. Zimmermann WO, Helmhout PH, Harts CC. [Guidelines for the prevention and treatment of overload injuries of the lower legs in young military service members.] Sport & Geneeskunde. 2015;1:6-19.

[In Dutch]

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9. Barnes M. Diagnosis and management of chronic compartment syndromes: A review of the literature.

Br J Sports Med. 1997;31(1):21.

10. Diebal AR, Gregory R, Alitz C, et al. Forefoot running improves pain and disability associated with chronic exertional compartment syndrome. Am J Sports Med. 2012;40(5):1060-7.

17. Dunn JC, Waterman BR. Chronic exertional compartment syndrome of the leg in the military.

Clin Sports Med. 2014;33(4):693-705.

18. Diebal AR, Gregory R, Alitz C, et al. Effects of forefoot running on chronic exertional compartment syndrome: a case series. Int J Sports Phys Ther.

2011;6(4):312-21.

19. Gefen A. Biomechanical analysis of fatigue-related foot injury mechanisms in athletes and recruits during intensive marching. Med Biol Eng Comput.

2002;40(3):302-10.

20. Stolwijk NM, Duysens J, Louwerens JW, et al.

Plantar pressure changes after long-distance walking. Med Sci Sports Exerc. 2010;42(12):2264-72.

21. Tsintzas D, Ghosh S, Maffulli N, et al. The effect of ankle position on intracompartmental pressures of the leg. Acta Orthop Traumatol Turc. 2004;43(1):42-8.

22. Romanov N, Fletcher G. Runners do not push off the ground but fall forwards via a gravitational torque.

Sports Biomech. 2007;6(3):434-52.

23. Daoud AI, Geissler GJ, Wang F. Foot strike and injury rates in endurance runners: A retrospective study. Med Sci Sports Exercise. 2012;44(7):1325-34.

24. Dallam GM, Wilber RL, Jadelis K, et al. Effect of a global alteration of running technique on kinematics and economy. J Sports Sci. 2005;23(7):757-64.

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25. Arendse RE, Noakes TD, Azevedo LB, et al. Reduced eccentric loading of the knee with the pose running method. Med Sci Sports Exerc. 2004;36(2):272-77.

26. Helmhout PH, Diebal AR, van der Kaaden L, et al.

The effectiveness of a 6-week intervention program aimed at modifying running style in subjects with chronic exertional compartment syndrome: Results from a series of case studies. Orthop J Sports Med. 2015;3(3): 2325967115575691 27. Zimmermann WO, Helmhout PH, Harts CC. [The treatment of MTSS and CECS in the Dutch military health care.] NMGT. 2014;67(3):72-82. [In Dutch] 28. Durnin JV, Womersley J. Body fat assessed from total body density and its estimation from skinfold thickness: Measurements on 481 men and women aged from 16 to 72 years. Br J Nutr. 1974;32:77-97.

29. Beurskens AJ, de Vet HC, KĂśke AJ, et al. A subjectspeciďŹ c approach for measuring functional status in

30.

31.

32.

33.

low back pain. J Manipulative Physiol Ther.

1999;22(3):144-8.

Wendel-Vos GC, Schuit AJ, Saris WH, et al.

Reproducibility and relative validity of the short questionnaire to assess health-enhancing physical activity. J Clin Epidemiol. 2003;56(12):1163-9.

Jaeschke R, Singer J, Guyatt GH. Measurement of health status. Ascertaining the minimal clinically important difference. Control Clin Trials. 1989 Dec;10(4):407-15.

Chumanov ES, Wille CM, Michalski MP, et al.

Changes in muscle activation patterns when running step rate is increased. Gait Posture. 2012;36(2):231-5.

Heiderscheit BC. Gait retraining for runners: In search of the ideal. J Orthop Sports Phys Ther.

2011;41(12):909-10.

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APPENDIX 1. Protocol of the Treatment Intervention Program

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APPENDIX 1. Protocol of the Treatment Intervention Program (continued)

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APPENDIX 2. Lower Leg Strengthening Exercises

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APPENDIX 3. Core Strengthening Exercises

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APPENDIX 3. Core Strengthening Exercises (continued)

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APPENDIX 4. Perception Exercises

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APPENDIX 5. Flexibility Exercises

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APPENDIX 5. Flexibility Exercises (continued)

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IJSPT

CASE REPORT

ACUTE TEARING OF THE OBLIQUE ABDOMINAL WALL INSERTION ONTO THE ILIAC CREST IN AN AUSTRALIAN FOOTBALL PLAYER: A CASE REPORT Myles Murphy, PT1, 2 Marshall Stockden, PT3 Bill Breidahl, MD4

ABSTRACT Background: Tears of the abdominal obliques have previously been reported in the vicinity of the lower ribs but they have not been reported in the vicinity of the iliac crest. The purpose of this case report is to describe the mechanism of injury and diagnosis of a distal abdominal oblique tear and subsequent rehabilitation programming.

Case Description: A 21-year-old male Australian football player experienced acute right-sided abdominal pain during a game while performing a commonly executed rotation skill. He was assessed clinically before being further examined with ultrasound and magnetic resonance imaging which revealed a rupture of the abdominal oblique wall at its insertion onto the iliac crest. The player then underwent a structured and graduated rehabilitation program with clear key performance indicators to optimize return to play and prevent recurrence.

Outcomes: The player was able to return to play at 35 days post injury and had no recurrence or complications at 12 month follow up post injury.

Discussion: This is the first time an abdominal oblique wall rupture at its insertion onto the iliac crest has been reported. In players with acute abdominal pain following twisting an insertional oblique tear should be considered as a differential diagnosis. A structured rehabilitation program may also help optimize an athlete’s return to play after distal abdominal oblique rupture.

Key Words: Abdominal Oblique, diagnostic ultrasound, Magnetic Resonance Imaging, side strain

1

School of Physiotherapy, University of Notre Dame Australia, Fremantle, WA, Australia 2 Medical Department, Peel Thunder Football Club, Mandurah, WA, Australia 3 Medical Department, Fremantle Football Club, Fremantle, WA, Australia 4 Perth Radiological Clinic, Subiaco, WA, Australia The study protocol has not been approved by any institutional review boards as it is a retrospective case study. The authors certify that they have no affiliations with or financial involvement in any organization or entity with a direct financial interest in the subject matter or materials discussed in this article.

CORRESPONDING AUTHOR Myles Murphy, School of Physiotherapy, University of Notre Dame Australia Fremantle, WA, Australia E-mail: myles.murphy1@my.nd.edu.au

The International Journal of Sports Physical Therapy | Volume 11, Number 7 | December 2016 | Page 1125

INTRODUCTION Tears of the abdominal obliques, also referred to as â&#x20AC;&#x153;side strainsâ&#x20AC;?, have been previously reported as a common injury in baseball pitchers,1 baseball position players1 and cricket bowlers (Appendix A).2,3 These injuries have also been reported in rowing,3 javelin,3 tennis,4 soccer5 and golf,3 (Appendix A) however, these injuries have not been reported in Australian Football players.

Abdominal oblique injuries usually occur during trunk rotation.1-3 This is potentially due to the role that the obliques have in producing trunk side flexion and rotation.6 The non-dominant abdominal obliques are more commonly injured compared to the dominant side.1-3 Internal oblique (IO) and external oblique (EO) injuries have been reported as strains or tears of the musculotendinous attachment in the vicinity of the lower ribs (Appendix A).1-5 No papers have been published reporting tears of the abdominal oblique at its insertion onto the iliac crest. The purpose of this case report is to describe the mechanism of injury and diagnosis of a distal abdominal oblique tear and subsequent rehabilitation programming.

CASE REPORT A healthy 21-year-old male Australian Football player (Height=182 cm, Weight=83 kg, BMI=25.1) rotated to the left while in a forward flexed posture to handball the football with his right (dominant) hand towards a teammate on his left side. During this commonly executed skill he experienced severe right sided abdominal pain (10 on a 10 Point Numerical Rating Scale of Pain) and had to be assisted from the field by the club doctor and physiotherapist.

No other players were in the vicinity at the time of injury to suggest a contact injury.

Initial off field assessment of the player was performed in supine due to his high level of pain. He was unable to perform a left or right active straight leg raise or cough without pain. The player also experienced pain with any lower limb muscle strength testing involving abdominal co-contraction. After a period of 15 minutes the player was able to stand with assistance of the club physiotherapist and doctor. In standing thoracolumbar range of motion was

severely restricted in all planes of movement due to pain. On palpation he had severe tenderness over the right iliac crest and through the distal third of the abdominal obliques. No pain was reproduced on thoracic, lumbar, sacroiliac or rib mobilization. No pain was reproduced with a hip flexion adduction internal rotation (FADIR) test, hip flexion abduction external rotation (FABER) test or hip quadrant test.

Given the normal assessment findings of the thoracic spine, lumbar spine and hip they were excluded as a sources of symptoms.

The player was immediately treated with basic pain medications (Paracetamol and Ibuprofen), an elastic compression bandage and ice before being transported home to rest. The next day the player had a radiograph and an ultrasound (US) of the right abdomen to assess potential iliac crest avulsion and/or distal abdominal oblique strain. US has been previously reported for assessing tears of the proximal portion of the abdominal obliques5,7 and it was deemed a logical and suitable modality to assist in confirming the clinical diagnosis. The US revealed a tear at the insertion of the right EO (Figure 1).

Given the extent of pain and functional limitations MRI was used to further assess the injury and to confirm the size of the tear. MRI has been reported as the gold standard for imaging proximal abdominal oblique injuries1-4 and it was assumed this was likely applicable to the distal oblique. MRI revealed tearing and retraction of the insertion of the internal and external oblique from the iliac crest (Figure 2, 3).

Two days following injury the player began on a graduated rehabilitation program consisting of four phases (Table 1) with clear key performance indicators (KPIs) for progression to the next phase (Table 2) before he returned to full match play at 35 days post injury. During stages one to three of the rehabilitation program the athlete was required to have pain of less than 3/10 on a Numerical Rating Scale.

He returned to sport without sustaining a re-injury and remained free of complications at a 12-month follow up. No further imaging was completed due to his uncomplicated rehabilitation.

Weekly load monitoring and player wellbeing data was retrospectively analysed to assess any potential contributing factors to the injury. Acute versus

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Figure 1. A. Longitudinal and B. Transverse sonographic images. There is an anechoic fluid collection (arrow) filling the defect created by the retracted muscle tear extending proximally from the echogenic iliac crest (star).

Figure 2. A. Coronal T1w image at the level of the iliac crests. The expected site of insertion of the right oblique abdominal muscles onto the iliac crest is outlined (dotted line) and the oblique abdominal muscle retraction is shown (dashed line). B. Coronal PD fat suppressed MRI at the same position. There is a fluid collection on the right between the proximally retracted oblique abdominal muscles (arrow) and the iliac crest.

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injury11 and may have contributed to the occurrence of the injury. However other potential injury risk factors such as recovery practices or nutrition were not assessed so it is possible that other contributing factors were involved.

Figure 3. Sagittal FSE T2w image at the level of the right iliac crest. An ovoid fluid collection (arrows) lies between proximally retracted oblique muscle fibres and the iliac crest.

chronic workloads as measured through Global Positioning System (GPS) tracking and self-reported loads in Arbitrary Units (AU) were assessed. Both metrics have been shown to predict soft tissue injury in AF players.8,9 The acute: chronic workload ratio was calculated by dividing the acute workload (1 week total) by the chronic workload (4 week total).10 GPS tracking included total weekly running and sprint (>25km/hour) distance per week.8 Self-scored AU were calculated by multiplying the players rating of perceived exertion for a specific training session by training duration.9 Training load was considered within normal limits and did not show any acute on chronic load spikes in the preceding six weeks. Player wellbeing screening recorded sleep quality (assessed on a visual analogue scale of 0-10), sleep duration (assessed in hours), self-rated fatigue (assessed on a visual analogue scale of 0-10) and stress levels (assessed on a visual analogue scale of 0-10). This data showed that in the two weeks prior to the injury the players sleep duration had decreased from an average duration of 8 hours to an average of 6.5 hours per night while all other data was within normal limits. A decrease in sleep duration has been shown to be a predictor of

DISCUSSION This case report describes the presentation of a distal abdominal oblique tendon rupture at the iliac crest in a male Australian Football player. However, rotational trunk injuries are reported in a variety of sports and the results and details contained in this case report may be valuable for anyone dealing with rotational trunk injuries. In athletes with acute, severe lateral abdominal pain following trunk rotation a tear of the distal abdominal oblique should be considered as a differential diagnosis and confirmed using US or MRI if available. Given the better correlation to clinical signs MRI imaging may be superior to US for assessing the extent of these injuries.

Valid and reliable measures of trunk strength are lacking in the literature and while functional isometric dynamometry of trunk flexion and rotation were performed, validity and reliability data for these tests does not exist and is an area for further research. A structured rehabilitation program with clear KPI’s provided an excellent progression allowing this athlete to regain full capacity in an optimal timeframe without subsequent re-injury.

The limitations of this case report include the potential lack of generalizability to other sports that more commonly report abdominal oblique injuries such as baseball and cricket. This case report also describes only the diagnosis and response to treatment of a single athlete and larger studies looking at rehabilitation of abdominal oblique injuries using reliable and validated outcome measures are needed. Tissue healing, assessed with US or MRI, was also not followed up in this athlete which may have provided further information on tissue healing.

CONCLUSION Distal abdominal oblique tendon tearing should be considered as a differential diagnosis for acute lateral abdominal pain following a rotational injury.

US and MRI are important adjuncts to confirm the clinical diagnosis and determine the extent of the

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Table 1. Rehabilitation Program

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Table 1. Rehabilitation Program (continued)

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Table 2. Key Performance Indicators (KPIâ&#x20AC;&#x2122;s) for Phase of Rehabilitation Progression

injury. Structured rehabilitation allowed this athlete to return to play within 35 days without re-injury.

REFERENCES 1. Conte SA, Thompson MM, Marks MM, Dines JS. Abdominal muscle strains in professional baseball: 1991-2010. Am J Sports Med. 2012;40:650-656.

2. Humphries D, Jamison M. Clinical and magnetic resonance imaging features of cricket bowlerâ&#x20AC;&#x2122;s side strain. Br J Sports Med. 2004;38:e21.

3. Connell D, Jhamb A, James T. Side Strain: A tear of internal oblique musculature. Am J Roentgenol.

2003;181:1511-1517.

4. Maquirriain J, Ghisi JP. Uncommon abdominal muscle injury in a tennis player: Internal oblique strain. Br J Sports Med. 2006;40:464-463.

5. Dauty M, Menu P, Dubois C. Uncommon external oblique muscle strain in a professional soccer player: A case report. BMC Research Notes.

2014;7:684.

6. Kumar S, Narayan Y, Kedka M. An electromyographic study of unresisted trunk rotation with normal velocity among healthy subjects. Spine.

1996;21(13):1500-1512.

7. Obaid H, Nealon A, Connell D. Sonographic appearance of side strain injury. Am J Roentgenol.

2008;191:264-267.

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8. Colby MJ, Dawson B, Heasman J, Rogalski B, Gabbett TJ. Accelerometer and GPS-derived running loads and injury risk in elite Australian footballers. J Strength Cond Res. 2014;28(8):2244-2252.

9. Rogalski B, Dawson B, Heasman J, Gabbett TJ. Training and game loads and injury risk in elite Australian footballers. J Sci Med Sport. 2013;16:499503.

10. Hulin BT, Gabbett TJ, Lawson DW, Caputi P, Sampson JA. The acute:chronic workload ratio

predicts injury: high chronic workload may decrease injury risk in elite rugby league players. Br J Sports Med. 2016;50(4):231-236.

11. Bhattacharyya N. Abnormal sleep duration is associated with a higher risk of accidental injury.

Otolaryngol Head Neck Surg. 2015;153(6):962-965.

APPENDIX A. Review of Previous Cases of Abdominal Oblique Muscle Injury Author

Sport

Onset

Side

Recovery

Imaging

(days) Conte et al (2012)

Conte et al (2012)

Humphries and Jamison (2004) Humphries and Jamison (2004) Humphries and Jamison (2004) Humphries and Jamison (2004) Humphries and Jamison (2004) Humphries and Jamison (2004) Humphries and Jamison (2004)

Baseball Pitchers n= 173

Baseball Position Players n= 220

Not Reported

Not Reported

Mean Ipsilateral= 21.9%

Mean Ipsilat= 44.5

Mean Contralateral = 78.1%

Mean Contralat= 32.8

Mean Ipsilateral= 29.7%

Mean Ipsilat= 21.2

Mean Contralateral = 70.3%

Mean Contralat= 28.9

Imaging Findings

Not reported

Not reported

I/O or E/O strain in vicinity of lower ribs or intercostal or rib muscle strains = 92% of cases I/O or E/O strain in vicinity of lower ribs or intercostal or rib muscle strains = 92% of cases Tear E/O at rib 10

Cricket n=1

Acute

Non Bowling Arm

35

MRI

Cricket n=1

Acute

Non Bowling Arm

70

MRI

Tear E/O at rib 10

Cricket n=1

Acute on Chronic

Non Bowling Arm

1

MRI

No abnormality

Cricket n=1

Acute

Non Bowling Arm

34

MRI

No abnormality

Cricket n=1

Gradual

Non Bowling Arm

4

MRI

No abnormality

Cricket n=1

Gradual

Non Bowling Arm

35

MRI

Transversalis Strain

Cricket n=1

Acute

Non Bowling Arm

28

MRI

Tear E/O ribs 9, 10, 11

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APPENDIX A. Review of Previous Cases of Abdominal Oblique Muscle Injury (continued) Author

Sport

Onset

Side

Recovery (days)

Imaging

Imaging Findings

Humphries Cricket Acute Non Bowling 15 MRI Partial Tear and n=1 Arm I/O at rib 11 Jamison (2004) Humphries Cricket Acute Non Bowling 55 MRI Tear I/O at and n=1 Arm rib 11 Jamison (2004) Humphries Cricket Gradual Non Bowling 20 MRI Strain I/O at and n=1 Arm rib 12 Jamison (2004) Dauty, Soccer Acute Not Reported 21 US Strain E/O at n=1 rib 11 Manu and Dubois (2014) Acute Not Reported Not MRI 10mm Partial Cricket Connell, Reported Tear I/O at Jhamb and Bowler n=1 10th costal James (2003) cartilage Golfer Acute Not Reported Not MRI 20mm Connell, Reported Complete Jhamb and n=1 Tear I/O at James 10th rib (2003) Connell, Cricket Acute Not Reported Not MRI 20mm Jhamb and Bowler Reported Complete James n=1 Tear I/O at (2003) 11th rib Acute Not Reported Not MRI 30mm Cricket Connell, Reported Complete Jhamb and Bowler Tear I/O at n=1 James 11th rib (2003) Connell, Javelin Acute Not Reported Not MRI 10mm Partial Reported Tear I/O at Jhamb and n=1 ribs 10, 11 James (2003) Acute Not Reported Not MRI 8mm Partial Cricket Connell, Reported Tear I/O at Jhamb and Bowler n=1 ribs 10 James (2003) Acute Not Reported Not MRI 32mm Cricket Connell, Reported Complete Jhamb and Bowler Tear I/O at n=1 James ribs 11 (2003) Acute Not Reported Not MRI 35mm Connell, Cricket Reported Complete Jhamb and Bowler Tear I/O at James n=1 ribs 10 (2003) Connell, Cricket Acute Not Reported Not MRI 15mm Reported Complete Jhamb and Fielding Tear I/O at (Throwi James ribs 11 (2003) ng) n=1 Connell, Rower Acute Not Reported Not MRI 6mm Partial Jhamb and n=1 Reported Tear I/O at James rib 10 (2003) MRI Strain I/O Acute Non Maquirriain Tennis n=1 Dominant and Ghisi Arm (2006) Imaging Findings Glossary: I/O, Internal Oblique; E/O, External Oblique; Ipstlat, Ipsitlateral; Contral, Contralateral; Strain, muscle oedema without fibre disruption; Tear, muscle fibre or musculotendinous disruption.

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APPENDIX B Hand held dynamometry (HHD) was used to assess isometric trunk rotation (Figure 1) and side flexion (Figure 2). HHD has been used previously to assess trunk muscle strength with good reliability1,2 however given the assumed high strength in this population the previously reported techniques were modified to ensure that the therapist’s strength (ie ability to resist the athletes force) did not influence results.

Figure 1. Isometric HHD of Trunk Rotation. The athlete adopts a lunge position and performs trunk rotation while holding onto a non-extensible belt. The HHD is positioned between the belt and a fixed immobile pole to ensure that practitioner related bias in HHD is removed (Arrow).

Figure 2. Isometric HHD of Trunk Side Flexion. The athlete adopts a stance position with feet shoulder width apart and performs trunk side flexion while holding onto a non-extensible belt. The HHD is positioned between the belt and a fixed immobile pole to ensure that practitioner related bias in HHD is removed (Arrow).

REFERENCES 1.

2.

Bohannon RW, Cassidy D, Walsh S. Trunk muscle strength is impaired multidirectionally after stroke. Clinical Rehabilitation. 1995;9(1):47-51.

Newman BL, Pollock CL, Hunt MA. Reliability of measurement of maximal isometric lateral trunk-flexion strength in athletes using handheld dynamometry. Journal of sport rehabilitation. 2012;Technical Notes(6).

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IJSPT

CASE REPORT

AN INTERVENTION-BASED CLINICAL REASONING FRAMEWORK TO GUIDE THE MANAGEMENT OF THORACIC PAIN IN A DANCER: A CASE REPORT Michael Masaracchio, PT, PhD1 Kaitlin Kirker, SPT1 Cristiana Kahl Collins, PT, PhD1 William Hanney, PT, PhD2 Xinliang Liu, PhD2

ABSTRACT Background and Purpose: As a result of the anatomical proximity of the thoracic spine to the cervical, lumbar, and shoulder regions, dysfunction in the thoracic spine can influence pain, mobility, and stability across these areas. Currently, a paucity of evidence exists addressing treatment of individuals with primary thoracic pain, especially in young, athletic patients. Furthermore, current research discussing clinical reasoning frameworks focus on the differential diagnostic process. The purpose of this case report was to present a framework that describes the clinical reasoning process for the implementation and sequencing of procedural interventions for the management of a dancer with thoracic pain.

Case Description: A 21-year-old female dancer presented to physical therapy with a medical diagnosis of thoracic pain. The patient reported exacerbation of left thoracic pain with prolonged sitting, twisting/arching her back during dance, and lifting >15 lbs overhead. Examination revealed hypomobility with positive pain provocation during mobility testing of T1-T3 and the sternocostal junction of ribs 2-4, with associated muscle guarding palpated in the left iliocostalis thoracis and levator scapulae.

Outcomes: Following 10 visits, the patient had no pain, no functional deficits, and a Global Rating of Change (GROC) of +6. She returned to full competition, and a 3-month follow-up revealed continued success with dancing and a GROC of +7.

Discussion: This case report described the successful management of a dancer with primary thoracic pain using a clinical reasoning framework for the sequencing of procedural interventions, while incorporating Olsonâ&#x20AC;&#x2122;s impairment-based classification system. A combination of manual therapy techniques and neuromuscular control exercises were incorporated to address mobility, stability, mobility on stability, and skill level impairments, which allowed the patient to return to dance activities safely. Future studies should consider the development of further treatmentbased clinical reasoning frameworks that illustrate the importance of the sequencing within a session and across the episode of care.

Key Words: clinical reasoning, impairment-based classification, manual therapy, neuromuscular re-education, thoracic pain.

Level of Evidence: 4

1 2

Long Island University, Brooklyn, NY, USA University Central Florida, Orlando, FL, USA

The authors declare no conďŹ&#x201A;ict of interest of any kind.

There was no funding associated with this manuscript.

The authors would like to acknowledge Kara Kaplan for her willingness to give informed consent for use of the photos in this case report.

CORRESPONDING AUTHOR Michael Masaracchio, PT, PhD Long Island University, Department of Physical Therapy 1 University Plaza, Brooklyn, NY 11201 E-mail: michael.masaracchio@liu.edu

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BACKGROUND While primary thoracic pain has been cited as occurring less frequently than neck or low back pain,1 it can be equally disabling.2,3 The point prevalence for thoracic spine pain in the adult working population ranges from 3% to 70% with 10% to 38% for onemonth prevalence, 13% to 39% for three-month prevalence, and 25% to 55% for one-year prevalence.4 As a result of the anatomical proximity of the thoracic spine to the cervical, lumbar, and shoulder regions, dysfunction in the thoracic spine and/or rib cage can influence pain, mobility, and stability in these areas.5 While specific mechanisms for the benefits of manual therapy remain unclear, substantial evidence suggests that manual therapy interventions directed at the thoracic spine can lead to a decrease in pain and improvement in function in the thoracic spine and adjacent regions.6-16 Previous authors of low-level evidence have suggested a combination of manual therapy and exercise in the treatment of individuals with thoracic spine pain.17-21 However, optimal interventions for the management of primary thoracic pain have yet to be determined.

Similar to the cervical and lumbar spine, it often is not feasible to identify pathoanatomical diagnoses as a specific cause of pain in the thoracic spine. Moreover, pathoanatomical diagnoses do not necessarily provide clinicians with relevant information in the clinical decision making process for treatment planning. An alternative method for diagnosis is through the implementation of Olson’s impairment-based classification system,22 which breaks down thoracic disorders into several categories based on examination findings and provides suggestions for treatment interventions (Table 1).22 However, while this impairment-based classification system is a good first step in the clinical management of individuals with primary complaints of thoracic pain, it does not provide the clinician with a comprehensive plan of care. A thorough treatment plan must be based on a sound clinical reasoning framework that goes beyond mobility issues to address all aspects of the movement system.

Clinical reasoning has most recently been defined as “a reflective process of inquiry and analysis carried out by a health professional in collaboration with a patient with the aim of understanding the patient, their context, and their clinical problem in

order to guide evidence-based practice.”23 Several clinical reasoning approaches—including the most frequently considered models: deductive reasoning (hypothetico-deductive model) and inductive reasoning (pattern recognition)24—have been thoroughly discussed in the literature and are commonly implemented in clinic practice. However, the majority, if not all identified clinical reasoning approaches are strongly concentrated on the examination and differential diagnosis process.24 An assumed understanding among clinicians that interventions progress from manual therapy, to neuromuscular re-education, to therapeutic exercise fails to take into account the complex procedural reasoning strategies necessary for the development of an appropriate treatment plan. In order for clinicians to provide effective management strategies throughout the episode of care, the clinical reasoning paradigm must shift its focus from differential diagnosis to treatment planning.

The American Physical Therapy Association (APTA) has recently proposed a new mission statement centered around the human movement system,25,26 that facilitates the expansion of an approach that guides the sequencing of interventions during patient management. It encourages physical therapists, as experts of the movement system, to design treatment plans that ultimately assist patients in returning to their desired level of pain-free function and skill. One approach to developing a physical therapy treatment plan is to incorporate our understanding of motor task requirements of functional movement into the clinical reasoning process for treatment planning. As physical therapists we understand that mobility, stability, mobility on stability, and skill are motor task requirements of all functional movements.27,28 This suggests a natural sequencing for the progression of treatment interventions throughout the episode of care. Therefore, the purpose of this case report was to present the clinical reasoning process associated with the development and implementation of a treatment plan for the management of a dancer with thoracic pain across the episode of care.

CASE DESCRIPTION: Patient Characteristics The patient was a 21-year-old female dancer who presented to physical therapy with a medical diag-

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Table 1. Impairment-based classiďŹ cation system for the thoracic spine. Adapted from Olson, Manual Physical Therapy of the Spine.22

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nosis of thoracic pain (ICD 10: M54.6). The patient intake form showed no significant past medical or surgical history. Current medications included birth control and Motrin for pain as needed. The patient was educated not to change her medication for the duration of the episode of care. The patient reported an insidious onset of left thoracic pain beginning eight months prior to the initial visit. The patient reported that at that time she was dancing seven hours per week and performing contemporary dance routines. Three months following the onset of pain, the patient increased her dancing to 30 hours per week. This intensity was maintained for three months, during which time her thoracic pain increased from 3-4/10 to 7/10 on the Numeric Pain Rating Scale (NPRS). Upon conclusion of competition, the patient was not scheduled to dance for the following two months. When the pain did not subside after one month of rest, the patient sought medical care from her primary care physician and was referred to physical therapy.

History At the initial examination, the patient reported that she had returned to dancing three weeks earlier and was performing ballet, hip hop, and jazz approximately 25-30 hours per week. The patient reported constant achy/sharp pain localized to the left side of the upper and middle thoracic spine (T3-T5) with

no reports of radicular symptoms. She was unable to identify any position that made the pain better, but stated that the pain subsided an hour into dancing and did not affect her ability to sleep. Throughout the day, her thoracic pain varied between 4/10 and 7/10, with an average pain intensity of 6/10.

Aggravating factors, as indicated on the Patient Specific Functional Scale (PSFS), included sitting in one place for more than 30 minutes, twisting/arching her back during dance movements, and lifting more than 15 lbs overhead. The baseline Neck Disability Index (NDI) and PSFS Scale were 32% and 4/10, respectively (Table 2). The patientâ&#x20AC;&#x2122;s goals for physical therapy included returning to pain-free dancing, being able to sit for at least 4-5 hours without pain, and resuming all overhead activities without pain.

CLINICAL IMPRESSION #1 In the absence of significant past medical history, past surgical history, and red flags, the patientâ&#x20AC;&#x2122;s overall history and subjective findings were consistent with a musculoskeletal spine dysfunction. In addition, the ability of the patient to identify exacerbating and relieving factors, along with uninterrupted sleep made the likelihood of sinister pathology extremely low. Pattern recognition was utilized at this point in the reasoning process to arrive at the initial diagnostic hypothesis. A thorough physical examination assessing range of motion (ROM), muscle strength, joint

Table 2. Pertinent Examination Findings and Outcome Measures

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mobility, and palpation was indicated to confirm the hypothesis of mechanical thoracic spine pain generated from the subjective portion of the initial examination and to definitively rule out serious medical pathology such as cancer, thoracic aortic aneurysm, myocardial ischemia, cholecystitis, etc.

EXAMINATION A complete neuromusculoskeletal examination was performed, assessing for potential red flags to treatment interventions. A static structural inspection revealed right side bending at the upper cervical spine, a slight forward head posture, and a flat thoracic spine. Reflexes, dermatomes, and myotomes were all intact and symmetrical bilaterally. Joint mobility assessment revealed hypomobility with positive pain provocation during posterior-to-anterior mobilization of T1-T3 and anterior-to-posterior rib mobilization at the sternocostal junction of ribs 2-4 on the left side. During mobility assessment, rib 4 on the left was anteriorly displaced with associated tenderness to palpation (TTP). In addition, TTP with associated muscle guarding was elicited in the left iliocostalis thoracis and left levator scapulae.

A breathing assessment revealed limited diaphragmatic action on the left side, with excessive left upper chest excursion. For additional key examination findings see Table 2.

CLINICAL IMPRESSION #2 The addition of the clinical examination findings confirmed the initial hypothesis of mechanical thoracic pain (ICD 10: M54.6). The primary complaint of thoracic pain, muscle imbalances, and segmental hypomobility in the thoracic spine and rib cage led to categorization of the patient into the thoracic hypomobility subgroup of Olson’s22 impairment-based classification system (Table 1). The reproduction of thoracic symptoms and the absence of neck pain associated with cervical AROM further supported the patient’s classification into this subgroup (Table 2). Clinicians are strongly encouraged to implement multiple forms of clinical reasoning during the differential diagnostic process to minimize errors, such as confirmation bias.29 Both pattern recognition and the hypotheticodeductive reasoning processes were implemented to reach a final diagnostic hypothesis. Physical therapy was recommended for a total of 10 visits over a 10-week

period, with re-assessment at five weeks, 10 weeks, and a three month follow-up. It was hypothesized that the patient should respond well to a combination of mobility, stability, and controlled mobility interventions that would address both her impairment level dysfunction, the standardized objective functional outcome measures, and the patient’s goals.

INTERVENTIONS Manual therapy techniques, neuromuscular re-education, and therapeutic exercises were incorporated throughout the episode of care as indicated based on the patient’s presentation at each treatment session. While previous research on pattern recognition and the deductive reasoning process support the reasoning approach used for the development of a diagnostic hypothesis, no standardized clinical reasoning framework exists for the development and progression of procedural interventions.24 This case report aims to present a clinical reasoning framework based on motor development in order to guide the plan of care. For a complete description of all the interventions utilized in this case report, please see Table 3 and the Appendix.

Clinical Reasoning for the Plan of Care During initial treatment sessions, the proposed interventions associated with the thoracic hypomobility classification were utilized to guide clinical decision making. Thrust and non-thrust manipulation of the thoracic spine and rib cage, respectively, were performed, followed by postural exercises (Table 1).

While the impairment-based classification system provides clinicians with guidelines for the early management of spinal mobility and postural stability impairments in patients with thoracic pain, it does not address the remainder of the rehabilitation process for full return to pain-free movement and functional skills. The neuromuscular re-education of proper dynamic stability and controlled mobility (or mobility on stability) within each involved body segment and across segments is crucial to long-term pain-free functional skill. The authors suggest that when combined, Olson’s22 impairment-based classification system and our understanding of motor task requirements of functional movement27 provide a sound clinical reasoning process to guide the plan of care in the absence of strong scientific evidence.

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Table 3. Interventions

Session one: day of initial examination Treatment began with manual therapy techniques to address the mobility impairments of the mid thoracic spine, which are the key treatment interventions of

Olsonâ&#x20AC;&#x2122;s22 impairment-based classification system and the most fundamental motor task requirement for pain-free functional movement. These included soft tissue mobilization to the iliocostalis thoracis and leva-

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tor scapulae muscle immediately followed by a single thrust manipulation to the costotransverse joints of T3-T5 (Figure 1). At the conclusion of session one, the patient was educated to avoid static sitting positions for more than one hour, to perform 50 cervical retraction exercises throughout the day (5 sets of 10), and to refrain from dancing until further notice. Performing cervical retraction exercises multiple times a day is intended to facilitate long-term postural changes.

Sessions 2-7 The focus of the next six sessions was to continue to restore mobility throughout the joints and soft tissues of the thoracic spine and rib cage to promote balance across all segments of the spine for the facilitation of controlled mobility during functional activities. On the second session, anterior to posterior grade III non-thrust manipulations to the third and fourth ribs were performed to address the anteriorly displaced fourth rib, which had not been resolved by the previous thrust manipulation (Table 3, Appendix). In addition, on sessions four and five, a muscle energy technique directed at the serratus anterior was applied to further address the anteriorly displaced fourth rib (Table 3, Appendix).

During these sessions, neuromuscular re-education focused on stability and controlled mobility follow-

ing manual therapy interventions (Table 3). This was deemed necessary to develop strength and to teach the patient new movement patterns with proper motor control in the areas of newly gained mobility. Stability of the craniocervical region and upper thoracic spine was attained by using the craniocervical flexion test as a treatment intervention (Figure 2, Appendix). Neuromuscular re-education for the middle and lower trapezius muscle was among a number of controlled mobility exercises during this period of care (Figure 3, Appendix).

During session five, the patient subjectively reported an onset of new central cervical spine pain that may have been brought on by increased time studying and reading in poor postures. A re-assessment revealed hypomobility on posterior to anterior spring testing of C6-C7. The treatment plan was modified (Table 1) based on the new cervical impairments and nonthrust, grade IV posterior to anterior mobilizations to the spinous processes of C6-C7 (Table 3). The patient reported absence of cervical pain on session six, with return of pain on session seven. During this session, manual therapy to the cervical spine was performed as described above, resulting in resolution of pain.

Although the lead author considered the use of thrust manipulation, previous research comparing the effects

Figure 1. (A) Hand placement of costotransverse joint thrust manipulation. (B) Costotransverse joint thrust manipulation.

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Figure 2. (A) Craniocervical ďŹ&#x201A;exion test start position. (B) Craniocervical ďŹ&#x201A;exion test end position (chin tuck).

Figure 3. (A) Left lower trapezius strengthening start position. (B) Left lower trapezius strengthening end position.

of thrust and non-thrust manipulation of the cervical spine has not demonstrated any significant differences in outcomes.30-32 Furthermore, while the risks of vertebral artery dissection appear low in this particular patient, it is impossible to predict who may sustain an adverse reaction following cervical spine thrust

manipulation; therefore, non-thrust manipulation was chosen. All sessions were followed by a home exercise program aimed at reinforcing the neuromuscular reeducation introduced during that particular treatment session, in order to integrate the new, more efficient movement pattern into the patientâ&#x20AC;&#x2122;s daily life.

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Sessions 8-10 Interventions during the final three treatment sessions focused on the acquisition of motor control in specific functional movements and skill level activities required for this patient to return to dancing. These included quadruped rotational drills that closely resembled certain dance positions and movements (Table 3, Appendix). Additionally, the patient was educated on how to gradually resume dance practice with limitations in previously pain provoking postures until she was cleared for full return to activity.

OUTCOMES As healthcare providers are increasingly reimbursed based on the value of care delivered to patients, physical therapists will need to continue to implement evidence-based interventions that lead to measureable improvement in outcomes. Based on current evidence and clinical judgment, the primary author chose a combination of outcome measures for this case including an assessment of pain (NPRS), disability (NDI), functional skills (PSFS), and perceived improvement (Global Rating of Change - GROC).

These measures encompass all aspects of the movement system and provide objective data that is meaningful to the management of the patient. The outcome measures and their associated scoring metrics have been previously described in detail in several other peer-reviewed articles.8,10,14,33-38 Table 2 summarizes the changes observed in the various examination findings and outcome measures throughout the episode of care and at a 3-month follow-up. Previous research has documented the reliability, validity, and minimal clinically important difference (MCID) of the NPRS (2 points), NDI (14%), PSFS (2 points), and GROC (+3).33,35-39 At the time of discharge, MCID values were met for all of the included outcome measures. In addition, the patient reported improvement in all items listed on the PSFS: sitting in one place for more than 30 minutes, twisting/arching her back during dance movements, and lifting more than 15 lbs overhead.

DISCUSSION Physical therapists are equipped with a distinct body of knowledge and skills to guide the examination and management of neuromusculoskeletal dis-

orders. Using these tools, the ultimate goal should be the restoration of efficient, pain-free movement for all individuals seeking treatment. This case report demonstrated the successful achievement of this goal for a dancer with primary thoracic pain through the implementation of a clinical reasoning approach that combined Olsonâ&#x20AC;&#x2122;s22 impairment-based classification system and an understanding of the requirements of the movement system.27 Although the interventions described in this case are not novel, the authors suggest that implementing a clinical reasoning framework for the development and sequencing of a treatment plan led to a successful outcome of this patient.

Previous research has demonstrated the positive effects of thoracic spine thrust manipulation in the management of individuals with cervical, thoracic, and/or shoulder pain.6-9,11,12,14,15,40 Based on the examination findings in this case, the lead author first chose to perform a thrust manipulation to the costotransverse joints of T3-T5 (Table 2, Appendix). This particular technique may have alleviated the associated muscle guarding of the iliocostalis thoracis muscle and provided neurophysiological input that may have improved the motor recruitment of the deep neck flexors and scapulothoracic muscles.40,41 Olsonâ&#x20AC;&#x2122;s22 impairment-based classification system supported this initial choice of manual therapy, which improved the mobility throughout the soft tissues and joints of the thoracic spine, potentially providing a window of opportunity for improving stability of the deep neck flexors and controlled mobility of the scapulothoracic muscles over the next several sessions.

The authors emphasize the importance of manual therapy in the initial management of individuals with cervical/thoracic spine dysfunction. Its primary goal is to provide input to the nervous system that can lead to improvements in mobility, pain, and motor recruitment.41 However, manual therapy in isolation will not restore stability, controlled mobility, or skill. While therapeutic exercise and neuromuscular re-education are commonly implemented in clinical practice, delineation of specific interventions, and their progression, to address these aspects of the movement system is often vague. As the profession of physical therapy evolves, current research

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calls for the justification of therapists’ selection of manual therapy approaches to treatment. Recently, two different approaches have been widely discussed in the literature. The first, which has been implemented in several randomized clinical trials,7,8,10-12,14 incorporates a prescriptive treatment paradigm to maximize internal validity and minimize the potential for cofounding variables. Conversely, other trials30-32 have implemented a more pragmatic approach to manual therapy, in which the clinicians choose the dosage and type of technique based on the results of the clinical examination. Although this second approach potentially creates additional confounding factors to control for and may challenge the internal validity of the study, it also enhances the external validity and generalizability of the study findings. Regardless of the approach selected, manual therapy remains a passive intervention provided by the therapist, which alone does not allow for the patient’s acquisition of motor skill. Therefore, manual therapy must be combined with neuromuscular re-education of functional movement patterns in order to restore efficient, pain-free movement.

Previous research has documented the variety of clinical reasoning strategies used during the differential diagnostic process.24 The importance of ‘reasoning about procedures’ has also been presented.24 However, a clinical reasoning framework designed to systematically progress a patient through an episode of care has yet to be widely accepted in the scientific and clinical communities and may potentially lead to a wide variation in clinical practice. The authors postulate that a combination of an impairment-based classification system22 and the application of motor tasks requirements of functional movement27,42 is one treatment-based reasoning approach that may lead to optimal patient progression. This particular approach may also help clinicians engage in the process of meta-cognition, so that both reflectionin-action and reflection-on-action strategies can be implemented to provide a comprehensive and organized clinical reasoning framework that may assist the clinician’s clinical decision making throughout the various phases of rehabilitation.

Similar to the treatment-based classification systems for the cervical and lumbar spine, Olson’s impairment-based classification system22 enables the ther-

apist to assign the patient to a specific subgroup from which targeted interventions can be selected.

This could potentially reduce variability in practice and facilitate the streamline of initial interventions that have been supported by strong scientific evidence.7,8,10-12,14 An understanding of the motor tasks requirements of functional movement subsequently provides therapists with an organized method to specifically address neuromuscular control and functional skill for each individual patient. While there are no current studies that have explored this model, the authors argue that it speaks to the art of fostering pain-free functional movement patterns.

Combined, these approaches support the recently adopted mission statement of the APTA that focuses on the human movement system,25,26 enabling the attainment of the APTA’s new vision: to transform society and optimize the human experience.25 Although this case demonstrated a successful outcome, several limitations exist. First, case reports do not provide cause and effect relationships. It is possible, although unlikely, given the duration of the patient’s symptoms that spontaneous recovery would have occurred in the absence of treatment.

Second, it is difficult to identify which intervention provided the single greatest benefit. In this case, after receiving thrust manipulation and other manual therapy interventions during the first three sessions (Table 3), the patient was able to sit comfortably for four hours without an increase in pain and presented with a NPRS of 3/10, a NDI of 20%, and a GROC of +4 at the beginning of the fourth session. Although some of these measurements did not meet published MCID values,34,35 the authors suggest that the thrust manipulation was the impetus for improvement demonstrated from the initial examination. This is supported by previous research, which has demonstrated dramatic, short-term beneficial effects following thrust manipulation.7,8,10-12,14,43 Finally, and perhaps most importantly, the authors realize that this is not the only reasoning framework that can be utilized to successfully treat individuals with thoracic pain. However, we suggest that focusing the sequence of treatment on motor task requirements of functional movement may provide more specific guidelines for the various phases of rehabilitation. Other manual therapy and neuromuscu-

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lar rehabilitation approaches may have potentially resulted in similar patient outcomes. Independent of which approach one chooses to follow, the use of a sound reasoning paradigm for the development of the plan of care can provide physical therapists with the opportunity to deliver effective clinical care while meeting the demands of an ever changing healthcare system. Future studies should consider comparing different manual therapy and reasoning approaches in the management of younger individuals with primary complaints of thoracic pain in larger pilot or randomized clinical trials.

CONCLUSION This case report described the successful management of an individual with thoracic spine pain using a clinical reasoning framework that encouraged the combination of manual therapy, neuromuscular reeducation, and therapeutic exercises. While none of the interventions described are unique, this case report incorporated rationale for sequencing and selective implementation of common interventions across the episode of care that resulted in a return to pain-free functional movement.

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Gonzalez-Iglesias J, Fernandez-de-Las-Penas C, Cleland JA, Huijbregts P, Del Rosario Gutierrez-Vega M. Short-term effects of cervical kinesio taping on pain and cervical range of motion in patients with acute whiplash injury: A randomized clinical trial. J Orthop Sports Phys Ther. 2009;39:515-521.

Masaracchio M, Cleland JA, Hellman M, Hagins M. Short-term combined effects of thoracic spine thrust manipulation and cervical spine nonthrust manipulation in individuals with mechanical neck pain: A randomized clinical trial. J Orthop Sports Phys Ther. 2013;43:118-127.

Mintken PE, Cleland JA, Carpenter KJ, Bieniek ML, Keirns M, Whitman JM. Some factors predict successful short-term outcomes in individuals with shoulder pain receiving cervicothoracic manipulation: a single-arm trial. Phys Ther.

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Strunce JB, Walker MJ, Boyles RE, Young BA. The immediate effects of thoracic spine and rib manipulation on subjects with primary complaints of shoulder pain. J Man Manip Ther. 2009;17:230-236.

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17. Aiken DL, Vaughn D. The use of functional and traditional mobilization interventions in a patient with chronic thoracic pain: A case report. J Man Manip Ther. 2013;21:134-141.

18. Chok B, Wong WP. Treatment of unilateral upper thoracic vertebral pain using an eclectic approach.

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20. Kelley JL, Whitney SL. The use of nonthrust manipulation in an adolescent for the treatment of thoracic pain and rib dysfunction: A case report. J Orthop Sports Phys Ther. 2006;36:887-892.

21. Schiller L. Effectiveness of spinal manipulative therapy in the treatment of mechanical thoracic spine pain: A pilot randomized clinical trial. J Manipulative Physiol Ther. 2001;24:394-401.

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APPENDIX. Description of Select Interventions Manual Therapy Soft Tissue Mobilization to Iliocostalis Thoracis (Mobility)

Patient position: prone, with head and neck in neutral.

Therapist position: standing, at the side of the table, facing the patient.

Instructions • The therapist palpates the patient’s iliocostalis thoracis, along the rib angles, with the pads of the fingers.

•

Anterior to Posterior Rib 3-4 Mobilization (Mobility)

The therapist applies firm pressure longitudinally strumming along the muscle.

Patient position: supine, with head and neck in neutral.

Therapist position: standing, at the side of the table, facing the patient.

Instructions • Have the patient’s arms at the sides.

• The therapist contacts the medial aspect of rib 3-4 with the pad of one thumb.

• The therapist’s other thumb is placed over the dummy thumb that is contacting the rib.

• The therapist comes directly over the mobilizing hands.

• The therapist performs a mobilization from anterior to posterior along the medial aspect of the rib.

Manipulation CTJ (Mobility)

Patient position: supine, with the head and neck in neutral Therapist position: standing, next to the patient Instructions • Have the patient bend the knees and cross the arms over the chest.

• Roll the patient to one side.

• The therapist positions the hand using a pistol grip along the mid thoracic spine.

• The patient rolls back on the therapist’s hand.

• The therapist leans over the patient, taking up the slack in the soft tissues.

• The patient takes a deep breath and, on exhale, the therapist delivers a high-velocity, low amplitude manipulation from anterior to posterior.

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APPENDIX. Description of Select Interventions (continued) MET to Serratus Anterior (Mobility)

Patient position: sitting Therapist position: standing, behind the patient Instructions • Have the patient cross the arm over the chest and rest the hand on the opposite shoulder.

Neuromuscular Re-education Concentric / Eccentric Contraction of Lower Trapezius (Stability)

•

The therapist applies a downward force to the lateral aspect of the patient’s elbow.

•

Have the patient resist the force by performing an isometric contraction.

•

Have the patient hold the contraction for 8 seconds and rest.

•

Repeat 2 more times.

Patient position: right side lying, with the head and neck in neutral Therapist position: standing, next to the patient Instructions • The therapist contacts the inferior angle of the scapula with one hand using a lumbrical grip.

Craniocervical Flexion (Stability)

•

Have the patient actively perform the motion of scapular depression as the therapist provides resistance (concentric).

•

Tell the patient to slowly let the therapist win, as the therapist attempts to slowly elevate the scapula (eccentric).

Patient position: supine, with the head resting on the table Instructions • Place a blood pressure cuff under the patient’s external occipital protuberance.

• Have the patient hold the gauge and inflate the cuff to 20 mmHg. • Ask the patient to perform craniocervical flexion by pressing the back of the neck into the blood pressure cuff, elevating the needle to 22 mmHg. • Have the patient hold this for 10 seconds.

• Have the patient continue to increase the cuff by 2 mmHg and assess if the patient can maintain for 10 seconds.

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APPENDIX. Description of Select Interventions (continued) Therapeutic Exercise Standing Scapular Retraction in Squat (Controlled Mobility)

Patient position: standing, in a slight squat Instructions • The theraband is attached to a stable column.

• The patient begins with the elbow straight, holding the theraband in one hand.

• The patient retracts the scapula, keeping the elbow straight.

• The patient then bends the elbow pulling the theraband towards the patient.

• When the patient’s shoulder reaches neutral, the exercise is complete.

• The patient returns to neutral and repeats the exercise.

Left Lower Trapezius Strengthening (Controlled Mobility)

Patient position: prone, on a physioball Instructions • Have the patient place the arm in the scapular plane in full external rotation.

•

Left Middle Trapezius Strengthening (Controlled Mobility)

Have the patient lift the arm towards the ceiling, while retracting/depressing the scapula.

Patient position: prone, on a physioball Instructions • Have the patient place the arm in 90° of abduction and lift toward the ceiling, while retracting the scapula.

Left External Rotator Strengthening (Controlled Mobility)

Patient position: prone, on a physioball Instructions • Have the patient retract the scapula.

•

Have the patient place the arm in 90° of abduction and neutral rotation.

•

Have the patient perform full shoulder external rotation, while maintaining scapular retraction.

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IJSPT

CASE REPORT

FROM ACUTE ACHILLES TENDON RUPTURE TO RETURN TO PLAY – A CASE REPORT EVALUATING RECOVERY OF TENDON STRUCTURE, MECHANICAL PROPERTIES, CLINICAL AND FUNCTIONAL OUTCOMES Jennifer A. Zellers, DPT1 Daniel H. Cortes, PhD2 Karin Grävare Silbernagel, PT, PhD, ATC1

ABSTRACT Introduction: Achilles tendon rupture results in significant functional deficits regardless of treatment strategy (surgical versus non-surgical intervention). Recovery post-rupture is highly variable, making comprehensive patient assessment critical. Assessment tools may change along the course of recovery as the patient progresses – for instance, moving from a seated heel-rise to standing heel-rise to jump testing. However, tools that serve as biomarkers for early recovery may be particularly useful in informing clinical decision-making. The purpose of this case report was to describe the progress of a young, athletic individual following Achilles tendon rupture managed non-surgically, using patient reported and functional performance outcome measures and comprehensively evaluating Achilles tendon structure and function incorporating a novel imaging technique (cSWE).

Subject Description: The subject is a 26 year-old, female basketball coach who sustained an Achilles tendon rupture and was managed non-surgically.

Outcome: The subject was able to steadily progress using a gradual tendon loading treatment approach well-supported by the literature. Multiple evaluative techniques including the addition of diagnostic ultrasound imaging and continuous shear wave elastography (cSWE) to standard clinical tests and measures were used to assess patientreported symptoms, tendon structure, and tendon functional performance. Five assessments were performed over the course of 2-14 months post-rupture. By the 14-month follow-up, the subject had achieved full self-reported function. Tendon structural and mechanical properties showed similar shear modulus by 14 months, however, viscosity continued to be lower and tendon length longer on the ruptured side. Functional performance, evidenced by the heel-rise test and jump tests, also showed a positive trajectory, however, deficits of 12-28% remained between ruptured and non-ruptured sides at 14 months.

Discussion: This case report outlines comprehensive outcomes assessment in an athletic individual following nonsurgically managed Achilles tendon rupture using a wide variety of tools that capture different aspects of tendon health.

Interestingly, the course of recovery of patient symptoms, functional performance, and tendon structure do not occur in the same time frame. Therefore, it is important to assess patient outcomes using multiple outcome measures encompassing different aspects of patient performance to ensure the patient is progressing steadily with rehabilitation.

Key words: Elastography, imaging, rehabilitation, ultrasound, viscoelastic properties Level of Evidence: Level 4.

1 2

University of Delaware, Newark, DE Penn State University, State College, PA

Acknowledgements Research reported in this publication was supported by the National Institute of Arthritis and Musculoskeletal and Skin Diseases of the National Institutes of Health under Award Number R21AR067390 and NIH 1P30-GM103333. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This research was also supported by the Foundation for Physical Therapy and the University of Delaware Research Foundation.

CORRESPONDING AUTHOR Karin Grävare Silbernagel 540 South College Ave. Newark, DE 19713 E-mail: kgs@udel.edu

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INTRODUCTION Acute Achilles tendon rupture is a traumatic injury that causes significant functional deficits. These deficits have been found to persist for as long as 10 years post-rupture.1 Historically, surgical management of Achilles tendon rupture was most common, however, with advances in non-operative treatment protocols, rates of non-surgical management of acute Achilles tendon rupture are on the rise.2,3 For example, in Denmark the probability of having surgery after Achilles tendon rupture has decreased from about 60% to 40% in people between the ages of 18 and 30.3 While individual variation is noteworthy,4 functional outcomes between surgical and nonsurgical management have been found to be similar in the presence of comparable rehabilitation.5 It is unclear what factors may make an individual better suited for surgical versus non-surgical management. As increasing age and higher BMI have been associated with poorer prognosis following Achilles tendon rupture,6 it could be hypothesized that younger, healthier individuals may actually benefit from non-surgical management with a gradual yet aggressive tendon loading rehabilitation protocol due to their improved propensity to heal. To better identify individuals who may benefit from surgical versus non-surgical intervention, development of early, objective criteria, which can serve as prognostic indicators of long-term functional outcomes, would be beneficial.

Ultrasound (US) imaging has been used as an objective measure of tendon structural assessment post-rupture.7â&#x20AC;&#x201C;9 Tendon elongation, in particular, has been found to relate to performance on functional heel-rise tests9 as well as changes in triceps surrae muscle activation during gait.10 Recently, a new ultrasound technique, continuous shear wave elastography (cSWE) has been developed and validated in a population of individuals with healthy Achilles tendons and in one case of an individual with tendinopathy.11,12 This technique uses an external actuator to send a low-level vibration along the tendon. Ultrasound imaging is used to track tissue displacement and is used to calculate the speed that the wave travels along the tendon. The speed of the wave is then used in a biomechanical model to calculate the tendonâ&#x20AC;&#x2122;s shear modulus and viscosity.11 Other ultrasound elastography techniques have been inves-

tigated in the Achilles tendon rupture population and demonstrated change in tendon stiffness over time.13 Furthermore, mechanical properties early in recovery measured by tracking movement of tantalum beads inserted into the tendon tissue have been related to long-term functional outcomes.14 Despite these findings, the relationship between mechanical properties measured non-invasively by elastography and functional, clinical outcomes have not been elucidated.

The purpose of this case report was to track the progress of a young, athletic individual following Achilles tendon rupture using patient-reported and functional performance outcome measures with the addition of comprehensively evaluating Achilles tendon structure and function using diagnostic ultrasound imaging and cSWE. The treatment strategy used in this case has been previously described by Olsson, et al.,15 therefore, details regarding specific interventions will not be addressed in this report.

CASE DESCRIPTION The subject was a 26 year-old, (Body mass index: 24.5) who ruptured her Achilles tendon performing a running and cutting maneuver while coaching basketball. The subject was diagnosed with Achilles tendon rupture by clinical examination performed within two days of injury, and her physician referred her to physical therapy for non-surgical management secondary to subject preference. The subject presented to physical therapy using bilateral axillary crutches, non-weight bearing. The subject did not receive additional medical management in addition to physical therapy care. This study was approved by the University of Delaware Institutional Review Board and informed consent was obtained.

Intervention Strategy The subject attended a total of 10 physical therapy sessions consisting primarily of education regarding home exercise progression using a gradual tendon loading approach and evidence-based guidelines15 over the course of the first six months post-injury. Rehabilitation and evaluations were provided following established protocols, using four phases of rehabilitation as a guide, including: the controlled mobilization phase, the early rehabilitation phase, the late rehabilitation phase, and the return to play phase (Table 1).15,16 These

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Table 1. Rehabilitation stages Phase

Intervention

Milestones to guide progression to next phase

Timeframe

Controlled Mobilization

Immobilization in CAM boot with wedging (enough to approximate tendon ends)

Tendon callus and approximation of tendon ends seen on B mode ultrasound imaging

0-7 weeks

Weight bearing as tolerated

Ability to tolerate activities of daily living wearing a street shoe/sneaker with high heel counter

Wean of wedging/CAM boot between weeks 4-8

Early Rehabilitation Phase

Strengthening (initiated week 3): - Seated heel-rises from wedge to full plantar flexion - Inversion/eversion with band resistance - Foot intrinsic strengthening - Bilateral standing heel-rises (initiated at week 4) Continued prior strengthening exercises

Ability to perform unilateral, standing heel-rise

8-13 weeks

Completed straight plane running progression (able to run 2 miles without exacerbation of pain or stiffness)

14-22 weeks

Standing unilateral heel-rises Unilateral balance activity Dynamic balance activity: backward walking, side-stepping, figure-8 walking Manual intervention: subtalar joint mobilization Late Rehabilitation Phase

Standing, unilateral heel-rises with external resistance General lower extremity strengthening program Bilateral to unilateral countermovement jump and hopping (repeated jumping)

Ability to perform slow speed agilities (agility ladder, figure-8)

Neuromuscular electrical stimulation to the soleus Straight plane running (when able to perform > 5 unilateral heel rises at 16 weeks post-rupture)

Return to Sports Phase

Patient education: running progression with 3 days rest between bouts of running Agilities with progressively increasing speed: agility ladder, side shuffle, backward jogging, figure-8 jogging Sport-specific training: single hop throws, light basketball activity without competitor

Running limited by general deconditioning (able to run 4.5 miles)

23-26 weeks

Ability to independently progress basketball-related activity

Patient education: self-progression of basketball-related activity CAM=Controlled Ankle Movement (Aircast, Inc., Vista, CA)

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nemius myotendinous junction was measured using extended field of view imaging (Figure 2).9,17,18 Tendon thickness was measured bilaterally at the rupture site (6.4 cm proximal to the calcaneal notch) and at 2 cm proximal to the calcaneal notch on the non-ruptured side.

Following the controlled mobilization phase, a comprehensive test battery15,19 including self-reported measures, functional performance testing, diagnostic B mode ultrasound imaging, and cSWE was performed at two, four, seven, nine, and 14 months post-injury. The subject’s self-reported function and symptoms were measured using the Achilles Tendon Total Rupture Score (ATRS),20 the Physical Activity Scale (PAS),21 and the Tampa Scale of Kinesiophobia (TSK)22 in addition to a clinical interview.

Achilles tendon structure was assessed using B-mode ultrasound imaging for tendon length to gastrocnemius.17 Continuous shearwave elastography,11,12 was used to measure Achilles tendon mechanical properties including the tendon’s ability to resist shear forces (shear modulus) and the tendon’s viscosity.

For both ultrasonographic measures, the average of three trials is reported.

Figure 1. Extended field of view B mode ultrasound images across timepoints Note the resolution of the tendon gap between 1 and 3 weeks post-rupture, changes in thickness and echogenicity of the Achilles tendon (particularly beginning at 4 months).

protocols incorporate both time and criteria based guidelines for progression.

Assessment of Tendon Health During the controlled mobilization phase, the subject’s Achilles tendon health was primarily assessed using diagnostic US imaging (Figure 1). Achilles tendon length from the calcaneal notch to the gastroc-

Finally, ankle plantarflexor and Achilles tendon function was measured using an established test battery,19,23,24 including the counter movement jump (CMJ), drop counter-movement jump (drop CMJ), and heel-rise test for calf endurance. For the CMJ and drop CMJ, jump height was recorded. For the heel-rise test, repetitions to fatigue, maximum heel rise height, and total work (total work = total linear displacement * body weight) were recorded.

For both jumping tasks, the average of three trials is reported. This test battery has been studied in a healthy population for reliability, and contralateral limb performance has been suggested to be the best available comparison for the injured side.19 OUTCOME Self-Reported Outcomes The results of the subject’s self-reported outcomes on the ATRS, PAS, TSK and Foot and Ankle Outcome Score – Quality of Life (FAOS – QOL) subscale are shown in Table 2. From a self-reported symptoms and function standpoint, the subject returned to full

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Figure 2. Tendon length measurements using B mode ultrasound imaging Lines indicate measurement from calcaneal notch to gastrocnemius myotendinous junction and soleus insertion.

Table 2. Self-reported outcome measures

activities of daily living as well as running/coaching activity by seven months post-injury, evidenced by subjective interview as well as full recovery of Physical Activity Scale score (6 out of 6 total points) and Achilles Tendon Total Rupture Score (100 out of 100 total points). By 14 months, the subject had recovered the FAOS â&#x20AC;&#x201C; QOL subscale score. The subject reported unchanging levels of kinesiophobia per the TSK. Outcomes of Ultrasound Examination At the one week timepoint, diagnostic ultrasound imaging along with a clinical examination was performed and confirmed a complete, acute, Achilles tendon rupture, with a 0.2 cm gap between tendon ends. Achilles tendon length to the gastrocnemius was 20.0 cm and tendon length to the soleus insertion was 9.0 cm on the ruptured side. Beginning at

the two-month timepoint, increased Achilles tendon length to the gastrocnemius myotendinous junction was observed on the ruptured side, which has been related to heel-rise ability.9 (Table 2) This lengthening averaged 2.5 cm difference between ruptured and non-ruptured sides across all timepoints. At the four month timepoint, shear modulus decreased on the ruptured side indicating alteration in tendon mechanical properties, with values restoring to those of the non-ruptured side by 14 months post-rupture.

(Table 3) Tendon thickness also showed an initial increase, which continued to increase through the seven-month timepoint before beginning to restore toward the values seen on the non-rupture side.

(Table 3) Subjective changes in tissue organization and echogenicity were seen across time points. (Figure 1) Viscosity was lower on the ruptured side, and did not recover to the value of the non-ruptured side

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Table 3. Recovery of mechanical properties over time

Figure 3. Limb symmetry indexes for tendon mechanical properties, heel-rise test (HRT), and Achilles tendon total rupture score (ATRS)

by 14 months. This may be related to changes in tissue composition.25 Recovery of mechanical properties indicated by limb symmetry indexes are shown in Figure 3.

Clinical Functional Outcomes Due to the acuity of injury, functional testing (strength, range of motion) was not performed at the one week timepoint. Over the course of this case report, heel-rise test performance on the ruptured side improved from seven unilateral heel rises

with a maximum height of 8.1 cm and total work of 357 Joules on the ruptured side at two months to 40 repetitions with a maximum height of 11.4 cm and total work of 2464 Joules at 14 months post-injury.

On the non-ruptured side, the subject was initially able to perform 24 repetitions with a maximum height of 15.7 cm and total work of 2,205 Joules at two months, progressing to 35 repetitions with a maximum height of 13.7 cm and total work of 2978 Joules at 14 months. Limb symmetry indexes for total work performed on the heel-rise test is shown

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Figure 4. Limb symmetry indexes for jump testing CMJ=counter movement jump

in Figure 2. Performance of the CMJ improved bilaterally, however, improvement was similar between sides causing limb symmetries to show little change.

(Figure 4) CMJ improved from 6.2 cm to 10.5 cm on the ruptured side and 9.7 cm to 14.55 cm on the nonruptured side between the two month and 14 month timepoints. Drop CMJ did show improved limb symmetries over the duration of the study (Figure 4), with the ruptured side improving from 5.6 cm to 10.1 cm and the non-ruptured side showing no improvement between the two and 14 month timepoints.

DISCUSSION This case report documents a successful outcome following non-surgical treatment of an Achilles tendon rupture in a young, athletic individual using a progressive tendon loading approach. While this treatment strategy has been used in other larger studies,15 this case report is unique due to the high activity level of the subject as defined by the PAS. Furthermore, this case reports details the use of a multi-faceted approach to outcomes assessment.

Self-reported tendon symptoms, tendon functional performance, and tendon structure all improved in

this subject, but the healing trajectory of all of these factors differed. This case report also described the utilization of established and novel imaging techniques throughout the subjectâ&#x20AC;&#x2122;s course of recovery to assist in clinical decision-making and assess progress.

Regardless of surgical versus non-surgical management, numerous studies have shown the benefit of early controlled loading of the Achilles tendon following rupture.5,15,26â&#x20AC;&#x201C;28 Early loading has been shown to decrease tendon elongation,27 improve tendon mechanical properties,26 and improve functional outcomes.15,28 In this case report, a step-wise progression of early tendon loading was conducted, first with exercises in controlled ranges of motion followed by weaning of immobilization, advancement of exercise load, and proprioception exercises and finally by the additions of dynamic and sport-specific activity. Use of a criteria-based progression15,16 allowed for safe advancement of activity and return to jumping and running, allowing the subject to steadily progress while mitigating risks of overloading the tendon.

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Importantly, the outcome data from this case report demonstrates that there is not a direct correlation of performance variables and structural recovery in tendon during rehabilitation. The subject’s selfreported function on two of the three self-reported questionnaires recovered by seven months post injury, which was substantially earlier than both structural and functional recovery of the tendon.

While structural and functional deficits were still observed at the final timepoint, Achilles tendon shear modulus seemed to follow a similar improvement trajectory as heel rise performance beginning at the four month timepoint. Between the two and four month timepoints, shear modulus decreased while total work performed on the heel-rise test steadily increased evidenced by limb symmetry indexes. This is potentially attributable to tendon remodeling as the gastrocnemius and soleus muscle function recovered. Prior studies support the recovery of elasticity post Achilles tendon rupture to be related to function recovery measured by subject self-report13 as well as performance on a heelrise task.14,27 In this case, viscosity recovered later and to a lesser extent compared to shear modulus, with trended in a positive direction first seen only at seven months post-rupture. The residual deficits seen at 14 months post-injury in this case are not unanticipated, however. Differences in tendon metabolism,29 length,9,30,31 and biomechanical properties13,32 up-to and exceeding the one year timepoint have been reported in prior studies.

Achilles tendon mechanical properties, measured using a variety of methods, have been reported to improve gradually over time following rupture.13,14,26,27,33 The results of this case report support these findings, although this case demonstrated a trend that has not been well described in the literature. Early in this subject’s recovery, upon transition from the controlled ankle movement (CAM) boot to street shoes, this subject showed a decline in tendon shear modulus and viscosity. From a clinical standpoint, this may suggest that increasing amounts of loading are needed to provide the signals necessary to initiate tendon remodeling and also provides insight as to why some patients may be more prone to re-rupture when weaning from immobilization. As elastography techniques become more established

and clinically available, incorporating advanced imaging into clinical decision making may allow for greater individualizing of rehabilitation progression.

This case report raises several important clinical concerns. It demonstrates that while clinicians must consider a patient’s subjective report of symptoms, it must not be at the exclusion of a comprehensive physical examination. In addition to the patient’s perceived function, recovery from tendon injury encompasses the assessment of important structural and functional components as well, which may not progress at the same rate or time as a patient perceives full resolution of symptoms. Incorporating assessment tools to monitor these different components of tendon function is crucial to fully understand a patient’s stage of tendon recovery and make appropriate decisions with regard to an individual’s rehabilitation.

The strength of this study is in the breadth, rigor, and novelty of outcome measures used to assess subject progress as well as the evidenced-based nature of the treatment provided. As is the case with all case reports, observed trends should not be applied to the general population until verified in a larger population of individuals. Furthermore, cSWE is not yet commercially available. Future studies are needed to continue to evaluate its responsiveness to change as well as to determine if there is a strong relationship between recovery of mechanical tendon properties to simpler, surrogate measures readily available to a physical therapist.

CONCLUSIONS In conclusion, this case report builds on a growing body of literature supporting the use of early, controlled Achilles tendon loading in the non-surgical management of individuals post Achilles tendon rupture. Diagnostic imaging techniques were used in the context of a comprehensive clinical examination that may help inform clinical decision-making in order to guide and individualize patient progress.

A comprehensive test battery, incorporating diagnostic US imaging and cSWE or surrogate measure, may help promote the use of criterion-based patient progression encompassing multiple aspects of tendon recovery in the future care of this population to maximize patient outcomes.

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REFERENCES 1. Lantto I, Heikkinen J, Flinkkila T, et al. Early functional treatment versus cast immobilization in tension after Achilles rupture repair: Results of a prospective randomized trial with 10 or more years of follow-up. Am J Sports Med. 2015;43(9):2302-2309.

2. Renninger CH, Kuhn K, Fellars T, Youngblood S, Bellamy J. Operative and nonoperative management of Achilles tendon ruptures in active duty military population. Foot Ankle Int. 2016;37(3):269-273.

3. Ganestam A, Kallemose T, Troelsen A, Barfod KW. Increasing incidence of acute Achilles tendon rupture and a noticeable decline in surgical treatment from 1994 to 2013. A nationwide registry study of 33,160 patients. Knee Surg, Sport Traumatol Arthrosc. 2015. [Epub ahead of print] 4. Olsson N, Nilsson-Helander K, Karlsson J, et al.

Major functional deficits persist 2 years after acute Achilles tendon rupture. Knee Surg, Sport Traumatol Arthrosc. 2011;19:1385-1393.

5. Soroceanu A, Sidhwa F, Aarabi S, Kaufman A, Glazebrook M. Surgical versus nonsurgical treatment of acute Achilles tendon rupture: A meta-analysis of randomized trials. J Bone Jt Surg. 2012;94:2136-2143.

6. Olsson N, Petzold M, Brorsson A, Karlsson J, Eriksson BI, Grävare Silbernagel K. Predictors of clinical outcome after acute Achilles tendon ruptures. Am J Sports Med. 2014;42(6):1448-1455.

7. Westin O, Nilsson Helander K, Grä vare Silbernagel K, Mö ller M, Kä lebo P, Karlsson J. Acute ultrasonography investigation to predict reruptures and outcomes in patients with an Achilles tendon rupture. Orthop J Sport Med. 2016;4(10):1-7.

isometric plantar flexion strength and cross-sectional area. J Orthop Res. 2015;33(6):926-931.

13. Zhang L, Wan W, Wang Y, et al. Evaluation of elastic stiffness in healing Achilles tendon after surgical repair of a tendon rupture using in vivo ultrasound shear wave elastography. Med Sci Monit.

2016;22:1186-1191.

14. Schepull T, Kvist J, Aspenberg P. Early E-modulus of healing Achilles tendons correlates with late function: Similar results with or without surgery.

Scand J Med Sci Sport. 2012;22:18-23.

15. Olsson N, Silbernagel KG, Eriksson BI, et al. Stable surgical repair with accelerated rehabilitation versus nonsurgical treatment for acute Achilles tendon ruptures: A randomized controlled study. Am J Sports Med. 2013;41(12):2867-2876.

16. Silbernagel KG, Brorsson A, Karlsson J. Rehabilitation following Achilles tendon rupture. In: Karlsson J, Calder J, van Dijk CN, Maffuli N, Thermann H, eds. Achilles Tendon Disorders: A Comprehensive Overview of Diagnosis and Treatment.

DJO Publications; 2014:151-163.

17. Ryan ED, Rosenberg JG, Scharville MJ, Sobolewski EJ, Thompson BJ, King GE. Test-retest reliability and the minimal detectable change for Achilles tendon length: A panoramic ultrasound assessment.

Ultrasound Med Biol. 2013;39(12):2488-2491.

18. Silbernagel KG, Shelley K, Powell S, Varrecchia S. Extended field of view ultrasound imaging to evaluate Achilles tendon length and thickness: a reliability and validity study. Muscles, Ligaments and Tendons Journal2. 2016;6(1):104-110.

8. Gitto S, Draghi AG, Bortolotto C, Draghi F. Sonography of the Achilles tendon after complete rupture repair: What the radiologist should know. J Ultrasound Med. 2016;35:e1-e8.

19. Silbernagel KGK, Gustavsson A, Thomeé R, Karlsson J, Thomee R, Karlsson J. Evaluation of lower leg function in patients with Achilles tendinopathy.

Knee Surg, Sport Traumatol Arthrosc. 2006;14(11):12071217.

9. Silbernagel KG, Steele R, Manal K. Deficits in heel-rise height and Achilles tendon elongation occur in patients recovering from an Achilles tendon rupture. Am J Sports Med. 2012;40(7):1564-1571.

20. Nilsson-Helander K, Thomeé R, Silbernagel KG, et al. The Achilles tendon total rupture score (ATRS): Development and validation. Am J Sports Med. 2007;35(3):421-426.

10. Suydam SM, Buchanan TS, Manal K, Silbernagel KG. Compensatory muscle activation caused by tendon lengthening post-Achilles tendon rupture. Knee Surgery, Sport Traumatol Arthrosc. 2015;23(3):868-874.

21. Grimby G. Physcial activity and muscle training in the elderly. Acta Med Scand. 1986;711:233-237.

11. Cortes DH, Suydam SM, Silbernagel KG, Buchanan TS, Elliott DM. Continuous shear wave elastography: A new method to measure viscoelastic properties of tendons in vivo. Ultrasound Med Biol. 2015;41(6):15181529.

12. Suydam SM, Soulas EM, Elliott DM, Silbernagel KG, Buchanan TS, Cortes DH. Viscoelastic properties of healthy Achilles tendon are independent of

22. Lundberg MKE, Styf J, Carlsson SG. A psychometric evaluation of the Tampa Scale for Kinesiophobia — from a physiotherapeutic perspective. Physiother Theory Pract. 2004;20(December 2003):121-133.

23. Silbernagel KG, Nilsson-Helander K, Thomeé R, Eriksson BI, Karlsson J. A new measurement of heel-rise endurance with the ability to detect functional deficits in patients with Achilles tendon rupture. Knee Surg Sport Traumatol Arthrosc.

2010;18:258-264.

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24. Silbernagel KG, Thomeé R, Eriksson BI, Karlsson J. Full symptomatic recovery does not ensure full recovery of muscle-tendon function in patients with Achilles tendinopathy. Br J Sports Med. 2007;41:276280; discussion 280.

25. Kannus P, Józsa L. Histopathological changes preceding spontaneous rupture of a tendon. A controlled study of 891 patients. J Bone Joint Surg Am. 1991;73:1507-1525.

26. Freedman B, Gordon J, Bhatt P, et al. Nonsurgical treatment and early return to activity leads to improved Achilles tendon fatigue mechanics and functional outcomes during early healing in an animal model. J Orthop Res. 2016. [Epub ahead of print] 27. Schepull T, Aspenberg P. Early controlled tension improves the material properties of healing human achilles tendons after ruptures: a randomized trial.

Am J Sports Med. 2013;41:2550-2557.

28. Nilsson-Helander K, Silbernagel KG, Thomeé R, et al. Acute achilles tendon rupture: a randomized, controlled study comparing surgical and nonsurgical treatments using validated outcome measures. Am J Sports Med. 2010;38(11):2186-2193.

29. Eliasson P, Couppé C, Lonsdale M, et al. Ruptured human Achilles tendon has elevated metabolic activity up to 1 year after repair. Eur J Nucl Med Mol Imaging. 2016;43(10):1868-1877.

30. Carmont MR, Grävare Silbernagel K, Brorsson A, Olsson N, Maffulli N, Karlsson J. The Achilles tendon resting angle as an indirect measure of Achilles tendon length following rupture, repair, and rehabilitation. Asia-Pacific J Sport Med Arthrosc Rehabil Technol. 2015;2(2):49-55.

31. Kangas J, Pajala A, Ohtonen P, Leppilahti J. Achilles tendon elongation after rupture repair: a randomized comparison of 2 postoperative regimens. Am J Sports Med. 2007;35:59-64.

32. Geremia JM, Bobbert MF, Casa Nova M, et al. The structural and mechanical properties of the Achilles tendon 2years after surgical repair. Clin Biomech.

2015;30(5):485-492.

33. Schepull T, Kvist J, Andersson C, Aspenberg P. Mechanical properties during healing of Achilles tendon ruptures to predict final outcome: a pilot Roentgen stereophotogrammetric analysis in 10 patients. BMC Musculoskelet Disord. 2007;8:116.

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IJSPT

CASE REPORT

A NON-OPERATIVE APPROACH TO THE MANAGEMENT OF CHRONIC EXERTIONAL COMPARTMENT SYNDROME IN A TRIATHLETE: A CASE REPORT Cristiana Kahl Collins, PT, PhD2 Brad Gilden, PT, DPT1

ABSTRACT Background & Purpose: Chronic Exertional Compartment Syndrome (CECS) causes significant exercise related pain secondary to increased intra-compartmental pressure (ICP) in the lower extremities. CECS is most often treated with surgery with minimal information available on non-operative approaches to care. This case report presents a case of CECS successfully managed with physical therapy.

Study Design: Case report Case Description: A 34-year-old competitive triathlete experienced bilateral anterior and posterior lower leg pain measured with a numerical pain rating scale of 7/10 at two miles of running. Pain decreased to resting levels of 4/10 two hours post exercise. The patient was diagnosed with bilateral CECS with left lower extremity ICP at rest measured at 36 mmHg (deep posterior), 36-38 mmHg (superficial posterior), and 25 mmHg (anterior). Surgery was recommended.

Interventions: The patient chose non-operative care and was treated with physical therapy using the Functional Manual Therapy approach aimed at addressing myofascial restrictions, neuromuscular function and motor control deficits throughout the lower quadrant for 23 visits over 3.5 months.

Outcomes: At discharge the patient had returned to running pain free and training for an Olympic distance triathlon.

The Lower Extremity Functional Scale improved from 62 to 80. The patient reported minimal post exercise tightness in bilateral lower extremities. Left lower extremity compartment pressure measurements at rest were in normal ranges measuring at 11 mmHg (deep posterior), 8 mmHg (superficial posterior), 19 mmHg (anterior), and 10 mmHg (lateral). Three-years post intervention the patient remained pain free with a Global Rating of Change of 6.

Discussion: This case report describes the successful treatment of a triathlete with Functional Manual Therapy resulting in a return to competitive sports without pain.

Level of Evidence: Level 4 Key Words: Chronic Exertional Compartment Syndrome, fasciotomy, physical therapy, running

1 2

IPA Manhattan, New York, NY, USA Long Island University, Brooklyn, NY, USA

The authors report no conďŹ&#x201A;ict of interest.

CORRESPONDING AUTHOR Cristiana Kahl Collins, PT, PhD Physical Therapy Department Long Island University 1 University Plaza Brooklyn, NY 11201, United States 718-780-4521 E-mail: ckahl@liu.edu

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BACKGROUND & PURPOSE Chronic Exertional Compartment Syndrome (CECS) is a debilitating condition characterized by severe pain in the lower extremities (LE).1-4 It is defined as a condition of pain caused by exercise and often relieved by rest.5 If physical activity is continued the symptoms of CECS are believed to persist over time.6 CECS is most commonly seen in recreational and elite athletes, those involved in team sports requiring running, and in military recruits.1,5,7-10 The prevalence of CECS in the general population is unknown as many athletes reduce activity and do not seek medical care.11 While it is known that individuals suffering from CECS present with increased intracompartmental pressure (ICP),1,5,8,12 the etiology remains uncertain. The previous theory that the pain is caused by muscle ischemia from increased ICP has been refuted.13,14 Some researchers have proposed that pain is caused by increased stretch and tension in fascial tissues with possible compression of sensory nerves.15,16 Additional symptoms may include numbness and tingling in dermatomal distributions of the nerve within that compartment and weakness of the affected muscles.1 CECS can occur in the upper extremity but 95% of occurrences are in the LE.5,8 Most authors report four distinct lower leg compartments involved in CECS: anterior, lateral, superficial posterior, and deep posterior compartments with 95% of cases occurring in the anterior and lateral compartments.1,2,8,17,18 It has been reported that 87% of patients with CECS are involved in sports, with runners accounting for 69% of cases.8 Incidence is divided almost evenly between genders, with a median age at onset of 20 years.2,8 Pain is frequently predictable following a specific duration and intensity of exercise and symptoms are bilateral in 70-80% of cases.1,5,7,19,20 CECS can go undiagnosed with a typical delay of 22 months and is often misdiagnosed as symptoms commonly subside with rest.1,21 Differential diagnosis of CECS include medial tibial stress syndrome, stress fracture, fascial defects, nerve entrapment syndrome, popliteal artery entrapment syndrome, and claudication.1,5 The gold standard for definitive diagnosis is ICP measure at rest and at five minutes following exercise through a catheter connected to a manometer for a measure of intra-compartmental pressure.1,14,15,22-26 Less invasive diagnostic tests, often

used as part of the differential diagnosis, include MRI, infrared spectroscopy, ultrasound imaging, and Thallium 201 chloride scintigraphy with SPECT scanning however these have not been deemed sufficient for definitive diagnosis.25,27-29 The most commonly used pressure diagnostic criteria for CECS is as follows: pressure in any of the compartments greater than or equal to 15mmHg pre-exercise; elevation to 30mmHg one-minute post-exercise; or elevation to 20mmHg five minutes post-exercise.12 The paucity of evidence for non-operative care often drives athletes to quit their sport or opt for a compartmental fasciotomy, which is still the only evidence based approach to the management of CECS.1,8,10,30,31 While surgery is reported to have an 80% success rate, the 11-13% complication rate includes infection, hemorrhage, nerve damage, deep vein thrombosis, vascular injury, skin breakdown, sensory deficits, nerve entrapment, and complex regional pain syndrome.1,8,10,30-33 In addition, a 6-11% rate of recurrence has been reported following surgical release of CECS.1,14,34 Several researchers evaluating the effect of nonoperative treatment on CECS have demonstrated less than optimal success in reduction of long-term pain with most cases resulting in a decrease in level of activity or surgery.3,7,9,15,35-40 The most successful nonoperative approach to treatment requires athletes to stop exercising or decrease the intensity of training.

While this strategy leads to improvement, the symptoms tend to return when the athlete resumes exercising even if the return is gradual.1,5,21 A change in running form to a forefoot running strategy has been reported to result in improvement in pain levels and compartment pressures in 12 runners, especially those with anterior compartment pain.9,39 Massage resulted in short term symptomatic improvement in CECS with no significant reduction in compartment pressures and symptoms.41 The use of arch supports to change the biomechanical load on the LE has been tried without success.34 Minimal improvement has been noted following traditional physical therapy (PT) interventions such as stretching; modalities such as ice, heat or ultrasound; therapeutic exercises; strengthening; and anti-inflammatory medications.5,21 While it appears that CECS patients may have some improvement following manual therapy

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or functional training, alone these approaches do not appear to be sufficient in assisting the patient to full recovery. The use of a non-operative approach to treatment of CECS would be beneficial if it could prevent the risk, complications and costs related to surgical intervention. No cases exploring the effects of a comprehensive rehabilitation program addressing all aspects of the movement system42 in the management of CECS have been published to date.

The purpose of this case report is to describe a nonoperative, comprehensive approach to physical therapy, Functional Manual Therapy (FMT),43 in the treatment of a competitive tri-athlete with bilateral CECS who did not desire surgery. In the absence of a successful non-operative approach to the management of CECS, no randomized controlled and long-term trials investigating a comprehensive, nonoperative management approach have been conducted making a case report the most appropriate place to start.7 CASE DESCRIPTION Subject History The subject was a 34-year-old competitive tri-athlete who had been competing for six years. He presented with a 12-month history of progressive leg pain, ten-

derness, swelling and tingling in the posterior aspect of both legs and occasionally anteriorly. Symptoms were provoked with running and, to a lesser degree, with cycling. At the time of the initial PT examination, the subject was limited to running a maximum of two miles, two to three days per week, due to 7/10 bilateral pain on a numerical pain rating scale (NPRS) and tingling. The pain returned to a baseline level of 4/10 within two hours of running cessation. The subject had undergone a course of PT with another therapist consisting of modalities, massage, custom orthotics, stretching, and strengthening for three months with no change in symptoms. He continued to report persistent soreness and tingling in both the anterior and posterior lower legs.

Medical records indicated that ICP measures on the left side had been previously assessed. The treating physician chose to obtain pressures only on the left LE, despite bilateral presentation, in order to minimize the number of invasive testing procedures. Pre-exercise ICP measurements were taken of the anterior, deep posterior and superficial posterior compartments (Table 1). With all ICP measures higher than 15mmHg at rest, and the same symptoms bilaterally, the subject was diagnosed with CECS and bilateral fasciotomy was recommended.

The subject opted against surgery to pursue another

Table 1. Leg compartment Intercompartmental Pressure measures Baseline* Leg Compartment

4 months post discharge* At rest Post-exercise (within 1 minute) 19 mmHg 22 mmHg

L Anterior

25 mmHg

L Lateral

not measured†

10 mmHg

18 mmHg

L Superficial Posterior

36-38 mmHg

8 mmHg

12 mmHg

36 mmHg

11 mmHg

22 mmHg

R Anterior

not measured†

15 mmHg

20 mmHg

R Lateral

not measured†

9 mmHg

17 mmHg

R Superficial Posterior

not measured†

11 mmHg

20 mmHg

R Deep Posterior

not measured†

12 mmHg

22 mmHg

L Deep Posterior

*A medical decision was made to limit pre-intervention measures to the left lower extremity due to the invasive nature of the procedure. The assumption was made that a bilateral diagnosis would be applied given that symptoms were of equal intensity in both LE's. †Given the reduction in symptoms and the lack of medical necessity for follow ICP measures, Stryker catheter measures were not taken following the intervention period.

Abbreviations: L, left; R, right

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Table 2. Passive Range of Motion and Muscle Strength Range of Motion (ROM)

left

Baseline Week 1 Session 1

right

Post Intervention Week 14 Session 23 left right

Hip Extension

12°

10°

15°

18°

Hip IR

30°

30°

35°

38°

Hip ER

30°

30°

40°

44°

Hip Abduction

30°

30°

35°

35°

Ankle DF

15°

15°

20°

22°

Ankle PF

45°

45°

48°

50°

Ankle Inversion

35°

35°

38°

40°

Ankle Eversion

15°

18°

20°

22°

Manual Muscle Testing (MMT) Baseline Week 1 Session 1 Hip Abductors

3-/5

3-/5

Post Intervention Week 14 Session 23 4+/5 5-/5

Ankle Dorsiflexors

3+/5

3+/5

5/5

5/5

Ankle Evertors

4-/5

4-/5

5/5

5/5

Abbreviations: IR, internal rotation; ER, external rotation; DF, dorsiflexion; PF, plantarflexion.

course of PT with the goal of returning to pain free competitive running. The subject was informed and was in support of data in his case being submitted for publication.

diagnostic criteria for CECS, further supported this diagnosis. The subject was deemed appropriate for a full physical therapy examination.

EXAMINATION/EVALUATION

Systems Review A systems review and past medical history revealed no limitations or concerns beyond the musculoskeletal system with limitations in range of motion (ROM) and strength throughout the lower quadrant.

(Table 2) Clinical Impression #1 In the absence of a significant past medical or surgical history and any other signs or symptoms, the subjective presentation was consistent with CECS. The subject presented with no red flags for tibial fracture and nerve or vascular entrapment. The reproduction of symptoms with running, decrease in symptoms following rest, and intra-compartmental pressure measurements at rest meeting the

Tests and Measures The results of the initial examination can be found in Tables 2 and 3. The subject presented for the initial evaluation three months following medical diagnosis. During this period he remained unable to run secondary to pain. Anterior view of standing posture revealed that both tibias were externally rotated in relationship to the femur. During active squatting both knees deviated medially into a valgus position with absent dissociation of pelvic girdle motion from the lumbar spine resulting in excessive lumbar extension. In addition to limitations in ROM and strength, an observational gait analysis revealed noticeable pelvic girdle asymmetries between left and right in the transverse, frontal and sagittal planes. Bilateral early heel rise and a medial heel

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Table 3. Scores on Functional and Subjective Scales

LEFS NPRS

Baseline Week 1 Session 1 62

Post Intervention Week 14 Session 23 80

4/10 at rest 7/10 after running

0/10 at rest and after running

Abbreviations: LEFS, Lower Extremity Functional Scale; verbal NPRS, numerical pain rating scale

whip during push off were also noted. The subject demonstrated inadequate feed-forward response including the inability to maintain standing alignment when challenged with a perturbation to the shoulder in the four diagonal directions when testing the lumbar protective mechanism.44 While the validity and reliability of this perturbation test has not been established, the subject’s inability to maintain upright against a challenge was interpreted as ineffective dynamic core stability in static standing and used only as an additional functional test.

Since the patient had received a pair of custom foot orthotics from the previous physical therapist, an intervention often attempted in cases of CECS, the perturbations to the shoulder were also attempted with the custom foot orthotics in the shoe to assess their effect on the subject’s functional stability. No changes in the subject’s response to the test were noted possibly indicating that core feed-forward response was not affected by foot posture.

The subject was observed and video-recorded in the frontal and sagittal planes with a SONY Handycam (HDR-CX440) while running on a treadmill at 7.0 mph.

He reported pain beginning at 30 seconds of running and increasing until the examination was terminated at 90 seconds due to pain increasing to 7/10.45,46 The pain started in the posterior compartment of both LEs progressing to the anterior leg. Visual and video observation of the subject’s running pattern (video analysis through the program Live from Siliconcoach) revealed bilateral heel strike running pattern, decreased left push off, shorter left stride length as measured by tibial shank angle, right femoral adduction at mid-stance with a corresponding left pelvic drop representing a positive Trendelenburg sign.

ROM and strength measures revealed limitations across the lower quadrant (Table 2). Ankle mobility

was assessed by joint end-feel and the ability of muscles to lengthen or shorten when the ankle was moved passively. End-feel assessment is an integral part of the PT examination. A hard end feel may be indicative of joint dysfunction or soft tissue restriction and can help guide intervention.46 Ankle mobility was found to be limited secondary to restricted talocrural joint mobility with a hard end-feel in posterior talar glide with tight gastrocnemius-soleus and posterior tibialis muscles. Restrictions with a hard end-feel were also noted with calcaneal medial and lateral glide on the talus, talus medial and lateral glide on the tibia, navicular inferior glide, and cuboid inferior glide. Soft tissue mobility of the plantar aspect of the foot was restricted with increased tension present during hallux extension. A hard end-feel was also noted in the posterior glide of the distal tibia on the talus. While no significant restrictions were present in the pelvic girdle complex, asymmetries in alignment and mobility of the coccyx, sacrum and innominates were noted. The seated slump test47 was positive for neural tension in both LEs limiting passive knee extension with the lumbar spine in flexion and in extension. The slump test assesses limitations in knee extension range of motion secondary to mechano-sensitivity in neural tissues and has been shown to have excellent test-retest reliability (ICC=0.93-0.96, SEM= 2.6°-3.3°).48,49 The subject scored 62/80 in the Lower Extremity Functional Scale (LEFS) which is a valid measure for LE problems with excellent test-retest reliability (r = 0.86 to 0.94), a minimal clinically important difference (MCID) and a minimal detectable change (MDC) of 9 points each (90% CI)(Table 3).50 Clinical Impression #2 Examination findings of restricted ROM and strength combined with movement dysfunction across the

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lower quadrant and pain noted during running that decreased with cessation, in the absence of red flags for other conditions, further supported the diagnosis of CECS. The presence of articular, soft tissue, fascial and neural mobility restrictions throughout the lower quadrant was believed to be the cause of movement dysfunction noted during gait and while running. Based on the decreased stability in static standing, the observed running pattern and clinical experience, the therapist believed that the subjectâ&#x20AC;&#x2122;s decreased proximal stability control was also affecting distal mobility coordination during higher-level functional activities such as running. The decreased soft tissue and fascial extensibility evaluated in the gastrocnemius-soleus and posterior tibialis muscles and decreased mobility of the tibial-fibular interosseus membrane were believed to be contributing to decreased compartmental mobility during running.

The asymmetries noted in the pelvic girdle were believed to contribute to neural-fascial tension possibly affecting the mobility of tissues during running. The working hypothesis was that mechanical dysfunctions of soft tissue, fascia and joint within the lower quadrant were affecting the gait and running pattern leading to weakness and movement dysfunction and an inability to run efficiently and pain free.

Prognosis The subject was deemed a good candidate for physical therapy given his age, motivation, and active lifestyle. While supporting evidence for the nonoperative management of CECS is limited,40 the presence of mechanical, neuromuscular and motor control impairments throughout the lower quadrant appeared to be involved with the noted functional limitations making the subject a good candidate for a comprehensive approach to physical therapy including manual therapy, neuromuscular facilitation and motor control training. Discharge criteria included being able to run five miles pain free.

Intervention The episode of care lasted 3.5 months during which the subject was seen 1-2 visits/week for a total of 23 visits. A treatment plan based on the FMT clinical reasoning paradigm43 and the literature on CECS aimed to: 1) decrease subjective symptoms as mea-

sured via the NPRS and the LEFS; 2) enhance soft tissue, myofascial, neural-fascial and articular mobility as measured by joint mobility, neural tension, passive and active ROM, and end-feel; 3) training neuromuscular and motor control patterns for efficient running mechanics; and 4) optimizing function while recognizing regional interdependence, as measured by the LEFS and the subjectâ&#x20AC;&#x2122;s ability to return to running and cycling without pain. Following the FMT clinical reasoning paradigm,43 interventions addressed mechanical capacity, neuromuscular function and motor control impairments across the lower quadrant aiming to address all aspects of the movement system. Mechanical capacity was operationally defined as the quality and excursion of movement including mobility of joints (arthrokinematics, osteokinematics, and accessory motions) and soft tissues (skin, muscles, connective tissues, neurovascular structures, and viscera). Neuromuscular function was operationally defined as the neurophysiological ability of synergistic muscles to initiate a contraction with proper strength and endurance for a given task, including the ability to return to a state of muscular relaxation. Finally, motor control was operationally defined as the ability to learn and perform the skillful and efficient assumption, maintenance, modification and control of voluntary movement patterns and postures.51 This paradigm was followed within each treatment session and throughout the episode of care.

Inherent and unique to functional mobilization is the use of local or regional active movements and graded resisted contractions in three planes of motion designed to engage the barrier and enhance mobility.43 Also unique to FMT is that immediately following mobilization the therapist seamlessly progresses to the enhancement of neuromuscular function and motor control through aspects of proprioceptive neuromuscular facilitation (PNF) and functional training.43 The purpose of the initial treatments was to improve accessory mobility of articular structures and functional excursion of muscles identified to be restricted in the initial examination. It also aimed to enhance the muscles extensibility and ability to expand due to the increased blood flow for proper oxygenation during exertional contractions. A restriction was determined to be present when accessory or physi-

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ologic motion was limited and/or when motion presented with a hard end-feel. The treatment emphasized improvement of myofascial mobility and fascial extensibility of the four lower leg compartments through the functional mobilization techniques.43,52,53 In addition to the extensive focus on mobility of the lower extremities, treatment also addressed mobility of the lumbar spine, sacrum and coccyx as these are believed to be crucial to the function of the lower extremity.43 The regional interdependence of the upper and lower quadrants was addressed through functional activities aimed at enhancing dynamic core control and strength during functional tasks. Functional mobilization techniques utilized throughout the episode of care include soft tissue mobilization systematically addressing skin, superficial fascia, soft tissue attachments along bony contours and myofascial structures; and joint mobilization through functional mobilization or resistance enhanced manipulation.43 Changes resulting from these techniques were measured through the re-examination of active and passive joint motion, three-dimensional functional movement patterns, movement in weight bearing and non-weight bearing postures, and the end-feel assessment of accessory motions.43 See Appendix A for an outline and sequence of interventions used across the episode of care.

In the first and second treatment session, focus was placed on the soft tissue and articular mobility of the foot and ankle. Managing mobility of the plantar surface, calcaneus (Figure 1), talus (Figure 2), distal tibial-fibular articulation, interosseous membrane (Figure 3), fibular head, midfoot and forefoot is crucial to improving foot and ankle mobility to allow for proper LE function.43,52,53 The subject was then given a home exercise program to reinforce mobility gains through single limb stance and closed chain stability through mini-squats. The subject was also instructed to perform the abdominal series (Figure 4) 3x/day to facilitate the activation, strengthening and endurance of core muscles in preparation for gait activities. This series consists of multi-position isometric resistance facilitated by 1) bilateral LE flexion, 2) bilateral LE flexion/adduction, and 3) bilateral LE extension with a neutral position of the lumbar spine. Immediately following functional mobilization techniques, PNF lower extremity flexion/

Figure 1. a. Functional Mobilization of the Calcaneus - Lateral Glide. b. Functional Mobilization of the Calcaneus Medial Glide

adduction/external rotation and extension/abduction/internal rotation patterns were used to facilitate proper activation of the trunk allowing for adequate proximal stability for distal mobility of the LE (Figure 5). Prolonged holds of end range contractions were utilized to facilitate core muscle function in the trunk while the techniques of combination of isotonics and dynamic reversals were used to enhance coordination of motion in the LE.54 After the second treatment session the subject reported that his lower legs felt â&#x20AC;&#x153;released for the first time in yearsâ&#x20AC;? lasting a few days. As the function of local issues in the foot and ankle improved, the focus of treatment shifted to dysfunctions present at the hip and pelvic girdle to address regional interdependence.

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Figure 3. Functional mobilization of the tibial-fibular interosseous membrane

Figure 2. a. Functional Mobilization of the Talus - Lateral Glide. b. Functional Mobilization of the Talus - Posterior Glide.

In the third session, two weeks after the initial evaluation, treatment progressed to focus on articular and soft tissue mobility of the pelvic girdle in an effort to improve postural alignment and enhance standing and gait function.55-57 Functional mobilization of the lower quadrant was performed to restore symmetry and mobility in the coccyx, sacrum, innominate, lumbar spine and hips.43,52,53 With improved soft tissue and joint mobility of the lower quadrant, interventions focused on facilitating effective proximal stability for

Figure 4a-c. Abdominal Series: a series of isometric resistance exercises for initiation, strength and endurance of the core muscles.

Each position is held for 45 seconds it allowing for irradiation from the hip musculature to the trunk musculature. The whole series is repeated 33-5 times/day for first 2 months and then once/day prior to workouts. a) Use UE’s placed on the anterior LEs to resist bilateral hip flexion b) Use UEs placed criss-crossed on the anterior LEs to resist bilateral hip flexion/adduction c) Use UEs placed on the anterior shins to resist bilateral hip extension. Repeat 4a for approximately 10 seconds to conclude the series with bilateral hip flexion The International Journal of Sports Physical Therapy | Volume 11, Number 7 | December 2016 | Page 1167

Figure 6. Ankle Pivot PNF Patterns. The hip and knee are resisted isometrically in the mid-range of the PNF diagonal pattern of flexion/adduction/external rotation and knee flexion while the ankle “pivots” against resistance into concentric dorsiflexion and inversion. The number of repetitions is based on the patient’s ability to perform the pattern with proper form.

Figure 5. a. Resisted Lower Extremity PNF Flexion Patterns (hip flexion, adduction, external rotation with knee flexion and ankle dorsiflexion and inversion). Resistance is applied to all components of the pattern through the range of motion making sure that the core stabilizers are engaged creating a dynamic anchor for the lower extremity motion. The number of repetitions is based on the patient’s ability to perform the pattern with proper form.b. Resisted Lower Extremity PNF Extension Patterns (hip extension, abduction, internal rotation with knee extension and ankle plantarflexion and eversion).

Resistance is applied to all components of the pattern through the range of motion making sure that the core stabilizers are engaged creating a dynamic anchor for the lower extremity motion. The number of repetitions is based on the patient’s ability to perform the pattern with proper form.

distal mobility during functional activities through PNF patterns. Treatment focused on neuromuscular function for initiation, strength and endurance of LE movements necessary for gait through PNF neuromuscular re-education techniques including

pelvis anterior elevation and posterior depression, LE PNF diagonal patterns and ankle pivot patterns (ankle motions performed while the remainder of the LE is maintained in the midrange of the LE PNF diagonal pattern) (Figure 6).43 Following the third PT visit the subject was able to run three miles without pain despite some tightness in the triceps surae muscle group reporting a sense of increased freedom of movement in the lower back, pelvis and the LEs. Sessions four through six (weeks two and three of the episode of care) continued to focus on increasing mobility of the myofascial planes in the lower leg compartments through functional mobilization techniques (Figure 7), reinforcing proper gait mechanics, and improving core stability during functional activities through PNF diagonal patterns and techniques for each LE and trunk. Building on the home exercise program the subject was instructed to begin single leg dead lifts for hamstring strength and multi-plane single leg reaches for improved strength and stability of the lower quadrant as it relates to running. After the sixth session the subject reported being able to run four miles without any increased pain. Sessions seven through eleven consisted of progressing single leg strengthening and core exercises, mobilization of the gastrocnemius and soleus for increased muscle play (Figure 8) and continued functional mobilization

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Figure 7. Functional Mobilization of the Deep Posterior Compartment of the Lower Extremity. The patient actively flexes and extends the knee while a mobilization force is applied to the posterior compartment of the lower leg.

of the myofascial compartments of bilateral LE. By the ninth session the subject ran six miles reporting some soreness that improved significantly following the run. After eight weeks of FMT interventions the subject reported running six miles at 8.0 mph pace without any pain and feeling only tightness when stretching the plantarflexors after the run. PT was reduced to one visit/week focusing on continuing functional mobilization of the lower legs as deemed necessary in each session, general LE strength training and running gait training to a midfoot landing close to center of mass strategy. The subject was guided on cadence manipulation and corrective instruction to assist in transitioning the position of foot contact during running. The focus was to promote a more vertical tibia at foot strike minimizing braking forces and increasing acceleration.58-60 This position of the tibia, coupled with a cadence of 90 strides per minute, has been shown to reduce the impact of ground reaction forces at foot strike decreasing the incidence of injury and CECS.9,39,61 In addition the subject’s home exercise program included isometric high stepping against a wall (Figure 9 shows this exercise being performed against the therapist) facilitating maximal output of the hip extensors/abductors in a weight bearing position for improved strength and stability during pushoff .62 At 12 weeks the subject reported having no pain pre- or post-running and was able to return to training for an Olympic triathlon.

Figure 8. Functional Mobilization of the Gastrocnemius/ Soleus. The therapist flexes the patient’s knee and grasps the gastrocnemius-soleus muscles (a). While maintaining a posterior pull on the gastrocnemius-soleus muscles the therapist dorsiflexes the patient’s ankle and extends the knee (b).

OUTCOME The subject was seen for a total of 23 visits over three and a half months. At the time of discharge the subject had returned to running and training pain free with an 18-point improvement in the LEFS to 80/80, surpassing the 9-point MCID and the MDC. Goniometric measurements of ankle passive ROM have been shown to have strong intra-tester reliability (ICC2,3=0.85-0.96) and to have an MDC of 3.7°3.8°.63 Gains in all ankle passive ROM surpassed the established MDC.63 The subject also demonstrated increased strength across the LE musculature. While no MCID or MDC have been established for strength

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activity and returned to 0/10 with rest.

Figure 9. Resisted High Step. The therapist applies appropriate resistance to the stepping leg while allowing the patient to push forward with the stance leg as if taking a step forward.

testing, manual muscle testing is a valid and reliable clinical test of muscle strength.64 Repeat ICP measures on the left LE were re-examined four months following discharge. Resting and post-exercise measures (treadmill with incline of 5% and running pace of 7 mph) were taken. All ICP measures were within normal limits at rest and oneminute post exercise (Table 1). The subject continued to train rigorously and reported a global rating of change (GRC) of +6 on a 15-point scale indicating that the subject was a â&#x20AC;&#x2DC;great deal betterâ&#x20AC;&#x2122;. The GRC is considered a valid and reliable subjective measure of clinical improvement.65 Six months following discharge the subject completed an Olympic Triathlon without any pain. At a three-year follow up the subject presented with 0/10 pain at rest, 0/10 pain with no impact activity, and minimal pain (2/10) with high impact activity that did not cause cessation of

DISCUSSION CECS is a painful and often misdiagnosed condition causing significant lower leg pain in athletes, most commonly in runners.6 While PT is commonly attempted in the non-operative management of CECS, surgical fasciotomy of the involved compartment remains the standard approach to treatment given its high success rate in getting athletes back to running.1,8,10,30,31 While 80% successful, surgical intervention carries the inherent risk of all invasive procedures including infection, hemorrhage, nerve damage, soft tissue scarring, and sensory deficits among others.10,11,30,31,33 This case report presents the application of FMT, a comprehensive approach to physical therapy, in the treatment of a competitive athlete diagnosed with CECS. The systematic clinical management of mechanical, neuromuscular and motor control impairments across the lower quadrant, while considering principles of regional interdependence,66,67 provided this subject with enhanced functional capacity and a return to competitive running pain free without the risks and costs of surgical intervention.

While the source of pain in CECS may be the increased intra-compartmental pressures in the LE, it seems possible that this may be caused by mechanical dysfunctions in any aspect of the lower quadrant including the lumbar spine, pelvic girdle, hip, knee, foot, or ankle. Changes in landing patterns (forefoot, midfoot or rearfoot) along with the location of the strike relative to the center of mass have been shown to affect how ground reaction and impact transient forces (a force occurring at the beginning of the ground reaction force that is generated at heel strike)61 translate from the foot to the lumbar spine.68 It is reasonable to infer that a dysfunction anywhere along this continuum may affect how the foot functions during running possibly leading to soft tissue and fascial tension in the LE.67,68 This possibility supports the hypothesis that the clinical management of CECS must address all aspects of the movement system across the lower quadrant.

The subject described in this case reported significant improvements in the feeling of tightness and pain in the LE after only two sessions where the

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treatment focused on the mobilization of mechanical restrictions across the lower extremities. This immediate relief in pain did not translate into improved ability to run without pain until all impairments in the movement system were addressed across the lower quadrant. Due to the limitations inherent in a case report, it is not possible to discern which aspect of this comprehensive approach had the greatest influence or allowed the subject’s successful return to running. The authors hypothesize that addressing any one aspect of the movement system may provide temporary and partial relief while a comprehensive approach to alleviating impairments at all levels of the movement system across the lower quadrant would lead to the long-term return to participation in all functional activities pain free. This hypothesis is supported by a recent systematic review on the conservative management of CECS.40 The use of massage in one case series resulted in improvement in pain but follow up was only five weeks when the participants had not yet returned to running.40,41 Four researchers assessed a change in gait or running pattern and determined it to be successful in allowing a return to running but the longest follow-up was only one year.9,39,69,70 CONCLUSIONS The resolution of impairments and movement dysfunctions throughout the kinetic chain using the FMT approach, against the backdrop of previous failed attempts at PT, may have played a role in the subject’s return to competitive running and all functional activities without pain. The subject continued to do so three years post intervention. An understanding of the movement system as a complex system comprising of anatomic and physiologic structures and functions42 supports the need for PTs to look beyond local and specific tissue dysfunction and address all aspects of the movement system.

Future clinical trials exploring FMT as a systematic approach to the management of CECS are indicated.

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Howard JL, Mohtadi NG, Wiley JP. Evaluation of outcomes in patients following surgical treatment of chronic exertional compartment syndrome in the leg. Clin J Sport Med. 2000;10(3):176-184. de Fijter WM, Scheltinga MR, Luiting MG. Minimally invasive fasciotomy in chronic exertional compartment syndrome and fascial hernias of the anterior lower leg: short- and long-term results. Mil Med. 2006;171(5):399-403.

Englund J. Chronic compartment syndrome: Tips on recognizing and treating. J Fam Pract.

2005;54(11):955-960.

Fronek J, Mubarak SJ, Hargens AR, et al.

Management of chronic exertional anterior compartment syndrome of the lower extremity. Clin Orthop Relat Res. 1987(220):217-227.

Kitajima I, Tachibana S, Hirota Y, Nakamichi K, Miura K. One-portal technique of endoscopic fasciotomy: Chronic compartment syndrome of the lower leg. Arthroscopy. 2001;17(8):33.

Martens MA, Backaert M, Vermaut G, Mulier JC. Chronic leg pain in athletes due to a recurrent compartment syndrome. Am J Sports Med. 1984;12(2):148-151.

Wiley JP, Clement DB, Doyle DF, Tauton JE. A primary care perspective of chronic compartment syndrome of the leg. Physician Sportsmed.

1987;15:111-120.

Diebal AR, Gregory R, Alitz C, Gerber JP. Forefoot running improves pain and disability associated with chronic exertional compartment syndrome. Am J Sports Med. 2012;40(5):1060-1067.

Rajasekaran S, Hall MM. Nonoperative management of chronic exertional compartment syndrome: A systematic review. Curr Sports Med Rep. 2016;15(3):191-198.

Blackman PG, Simmons LR, Crossley KM. Treatment of chronic exertional anterior compartment syndrome with massage: A pilot study. Clin J Sport Med. 1998;8(1):14-17.

American Physical Therapy Association. Physical therapist practice and the human movement system.

2015; http://www.apta.org/MovementSystem/ Accessed December 2, 2015.

Johnson GS, Johnson VS, Miller RA, Rudzinski LD, Welsome KM. The functional mobilization approach.

In: Wise C, ed. Orthopedic manual physical therapy: from art to evidence. Philadelphia, PA: F.A. Davis; 2015:278-305.

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44. Saliba VL, Johnson GS. Lumbar protective mechanism. In: White A, Anderson R, eds.

Conservative Care of Low Back Pain: Williams & Wilkins; 1990.

45. Childs JD, Piva SR, Fritz JM. Responsiveness of the numeric pain rating scale in patients with low back pain. Spine (Phila Pa 1976). 2005;30(11):1331-1334.

46. Farrar JT, Portenoy RK, Berlin JA, Kinman JL, Strom BL. Defining the clinically important difference in pain outcome measures. Pain. 2000;88(3):287-294.

47. Maitland GD. The slump test: Examination and treatment. Aust J Physiother. 1985;31(6):215-219.

48. Nee RJ, Butler DS. Management of peripheral neuropathic pain: Integrating neurobiology, neurodynamics, and clinical evidence. Phys Ther Sport. 2006;7(1):36-49.

49. Tucker N, Reid D, McNair P. Reliability and measurement error of active knee extension range of motion in a modified slump test position: A pilot study. J Man Manip Ther. 2007;15(4):E85-91.

50. Binkley JM, Stratford PW, Lott SA, Riddle DL. The Lower Extremity Functional Scale (LEFS): Scale development, measurement properties, and clinical application. North American Orthopaedic Rehabilitation Research Network. Phys Ther.

1999;79(4):371-383.

51. American Physical Therapy Association. Guide to physical therapist practice. 2nd ed. Alexandria, VA: Amer Physical Therapy Association; 2003.

52. Johnson GS. Soft tissue mobilization. In: Donatelli R, Wooden M, eds. Orthopaedic Physical Therapy. 4th ed.

New York: Churchill Livingstone; 2010:599-640.

53. Rudzinski LD, Johnson G. Soft tissue mobilization in orthopaedic manual physical therapy. In: Wise C, ed.

Orthopedic manual physical therapy: from art to evidence. Philadelphia, PA: F.A. Davis; 2015:306-329.

54. Adler S, Beckers D, Buck M. PNF in Practice: An illustrated guide. 3rd ed. Germany: Springer; 2008.

55. Janda V. On the concept of postural muscles and posture in man. Aust J Physiother. 1983;29(3):83-84.

56. Kendall FP, McCreary EK, Provance PG, Rodgers MM, Romani WA. Muscles: Testing and Function with Posture and Pain. 5th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2005.

57. Lewis CL, Sahrmann SA. Effect of posture on hip angles and moments during gait. Man Ther.

2015;20(1):176-182.

58. Bezodis IN, Kerwin DG, Salo AI. Lower-limb mechanics during the support phase of maximumvelocity sprint running. Med Sci Sports Exerc.

2008;40(4):707-715.

59. Chumanov ES, Heiderscheit BC, Thelen DG. The effect of speed and influence of individual muscles on hamstring mechanics during the swing phase of sprinting. J Biomech. 2007;40(16):3555-3562.

60. Hasegawa H, Yamauchi T, Kraemer WJ. Foot strike patterns of runners at the 15-km point during an elite-level half marathon. J Strength Cond Res. 2007;21(3):888-893.

61. Lieberman DE, Warrener AG, Wang J, Castillo ER. Effects of stride frequency and foot position at landing on braking force, hip torque, impact peak force and the metabolic cost of running in humans. J Exp Biol. 2015;218(Pt 21):3406-3414.

62. Reiman MP, Bolgla LA, Loudon JK. A literature review of studies evaluating gluteus maximus and gluteus medius activation during rehabilitation exercises. Physiother Theory Pract. 2012;28(4):257268.

63. Konor MM, Morton S, Eckerson JM, Grindstaff TL. Reliability of three measures of ankle dorsiflexion range of motion. Int J Sports Phys Ther. 2012;7(3):279287.

64. Cuthbert SC, Goodheart GJ, Jr. On the reliability and validity of manual muscle testing: A literature review. Chiropr Osteopat. 2007;15:4.

65. Kamper SJ, Maher CG, Mackay G. Global rating of change scales: A review of strengths and weaknesses and considerations for design. J Man Manip Ther.

2009;17(3):163-170.

66. Reiman MP, Weisbach PC, Glynn PE. The hips influence on low back pain: A distal link to a proximal problem. J Sport Rehabil. 2009;18(1):24-32.

67. Sueki DG, Cleland JA, Wainner RS. A regional interdependence model of musculoskeletal dysfunction: research, mechanisms, and clinical implications. J Man Manip Ther. 2013;21(2):90-102.

68. Lieberman DE, Venkadesan M, Werbel WA, et al.

Foot strike patterns and collision forces in habitually barefoot versus shod runners. Nature.

2010;463(7280):531-535.

69. Kirby RL, McDermott AG. Anterior tibial compartment pressures during running with rearfoot and forefoot landing styles. Arch Phys Med Rehabil. 1983;64(7):296-299.

70. J J, WH C, H H, H B. Influence of the running shoe sole on the pressure in the anterior tibial compartment. Acta Orthop. 1995;61:190-198.

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APPENDIX A. Interventions Across the Episode of Care Interventions for Neuromuscular Function Impairments 1 - FM to superficial and deep - Neuromuscular re(exam) soft tissue in the plantar education for active &2 surface of the rearfoot, and resisted ankle, midfoot and forefoot knee and hip motions Week 1 - FM to accessory mobility of through PNF lower the calcaneus into extremity diagonal medial/lateral glide and patterns in supine gapping (Figure 1a & 1b) and sidelying (hip - FM to accessory mobility of flexion/abduction/int the talus into anterior/posterior ernal rotation, hip and medial/lateral glide extension/adduction/ (Figure 2a & 2b) external rotation, hip - FM to accessory mobility of flexion/adduction/ext the navicular into ernal rotation, hip posterior/inferior glide during extension/abduction/i a closed chain knee mini squat nternal rotation) - FM to tibia/fibula interosseus (Figure 5a & 5b) membrane (Figure 3) - Abdominal series Figure 4a-c)

Rx Session (Week #)

Interventions for Mechanical Capacity Impairments

- FM to soft tissues and soft tissue attachment to bony Week 2 contours across the lower lumbar spine, sacrum, innominate and coccyx - FM to sacral-coccygeal joint into bilateral rotation and lateral flexion - FM to right sacrum base P/A for form closure - FM to right innominate for inferior depression - FM to bilateral hip inferior glide

Interventions for Motor Control Impairments - Single limb stance with contralateral high stepping - Closed chain stabilization activities through mini-squats

3

- PNF bilateral pelvis anterior elevation and posterior depression - PNF LE flexion and extension patterns (Figure 5a & 5b) - PNF ankle pivot patterns of dorsiflexion/inversion and dorsiflexion/eversion with a fixed heel (Figure 6)

- Single limb stance with contralateral high stepping (Figure 9) - Cross extension high stepping against a wall for strengthening in new mobility ranges - Beginning to transition to mid-foot strike for running

4

- PNF anterior elevation and posterior depression pelvic patterns - PNF lower extremity diagonal patterns (Figure 5a & 5b)

- PNF gait training with a focus on weight shift and weight acceptance onto stance lower extremity

5&6

- PNF trunk patterns - PNF lower extremity diagonal patterns (Figure 5a & 5b)

- Single leg dead lifts - Multi-plane single leg reaches - PNF gait training with resistance to pelvis anterior elevation

- FM to lumbar spine for P/A and left rotation of L5-S1 Week 2 - FM to right innominate for internal, external and posterior rotation - FM to anterior and posterior glide of distal tibia and fibula - FM to anterior, lateral, superficial posterior and deep posterior compartments (Figure 7) - FM to right innominate for internal, external and posterior Week 3 rotation - FM to lumbar spine for P/A and left rotation of L5-S1 - FM to tibia/fibula interosseus membrane (Figure 3) - FM to anterior, lateral, superficial posterior and deep posterior compartments (Figure 7)

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APPENDIX A. Interventions Across the Episode of Care (continued) Interventions for Neuromuscular Function Impairments 7 - 11 - FM to accessory mobility of - PNF trunk patterns - PNF lower the calcaneus into extremity diagonal Week medial/lateral glide and gapping (Figure 1a & 1b) patterns (Figure 5a & 4-7 - FM to accessory mobility of 5b) the talus into anterior/posterior - PNF ankle pivot and medial/lateral glide in patterns of closed chain (figure 2a & 2b) dorsiflexion/inversio - FM to proximal fibular head n and A/P glide dorsiflexion/eversion with a fixed heel - FM to tibialis posterior - FM to anterior, lateral, (Figure 6) superficial posterior and deep - Segmental lower trunk rotation with posterior compartments (Figure 7) facilitation and - FM to accessory mobility of emphasis on lower lumbar spine for lumbar segmental control extension 12 - 18 - FM to accessory mobility of - PNF anterior the sacrum in form closure elevation and posterior depression Week - FM to iliopsoas, rectus pelvic patterns 8-11 femoris, vastus medialis and vastus lateralis for improved - PNF lower hip extension and knee flexion extremity diagonal range of motion patterns (Figure 5a & - FM to accessory mobility of 5b) the talus into posterior and - PNF ankle pivot anterior glide for dorsiflexion patterns of and plantarflexion in closed dorsiflexion/inversio chain, half-kneeling n and - FM to accessory mobility of dorsiflexion/eversion anterior and posterior glide of with a fixed heel distal tibia and fibula in closed (Figure 6) chain, half-kneeling - Reciprocal scapular - FM to accessory mobility of and pelvic PNF anterior and posterior glide of patterns for fibular head in closed chain, improved dynamic squatting control and - FM to accessory mobility of reciprocation during superior glide of navicular on gait and running talus in closed chain, hooklying - FM to gastrocnemius and soleus for improved muscle play (Figure 8a & 8b)

Rx Session (Week #)

Interventions for Mechanical Capacity Impairments

Interventions for Motor Control Impairments - Single limb stance strengthening through resisted high stepping (Figure 9) - Core strengthening through resistance to bilateral lower extremity flexion in supine - Lower trunk rotation from hooklying - Running mechanics with focus on continuing the transition to mid-foot strike - PNF gait training with resistance to pelvis anterior elevation - Resisted high step gait - Front/back & side/side mechanics drill - Running mechanics with a focus mid-foot strike

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APPENDIX A. Interventions Across the Episode of Care (continued) Rx Session (Week #)

19-23 Week 12-15

Interventions for Mechanical Capacity Impairments - FM to gastrocnemius and soleus for improved muscle play (Figure 8a & 8b) - FM to anterior, lateral, superficial posterior and deep posterior compartments (Figure 7)

Interventions for Neuromuscular Function Impairments - PNF anterior elevation and posterior depression pelvic PNF patterns - PNF lower extremity diagonal patterns (Figure 5a & 5b) - PNF ankle pivot patterns of dorsiflexion/inversio n and dorsiflexion/eversion with a fixed heel (Figure 6) - Reciprocal scapula and pelvic patterns for improved dynamic control and reciprocation during gait and running

Interventions for Motor Control Impairments - PNF gait training with resistance to pelvis anterior elevation - Resisted high step gait (Figure 9) - Front/back mechanics drill - Running mechanics with a focus mid-foot strike

*All neuromuscular function activities were performed with the techniques of prolonged isometric holds at the end of a new range and combination of isotonics using appropriate resistance throughout the available range of motion.50 Abbreviations: FM, functional mobilization; PNF, proprioceptive neuromuscular facilitation;

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IJSPT

CLINICAL COMMENTARY

POST OPERATIVE REHABILITATION OF GRADE III MEDIAL COLLATERAL LIGAMENT INJURIES: EVIDENCE BASED REHABILITATION AND RETURN TO PLAY Catherine A. Logan, MD, MBA, MSPT1 Luke T. O’Brien, B.Phty, M.Phty, (Sports), SCS2 Robert F. LaPrade MD, PhD3,4

ABSTRACT The medial collateral ligament is the most commonly injured ligament of the knee, with injury generally sustained in the athletic population as a result of valgus contact with or without tibial external rotation. The capacity of the medial collateral ligament to heal has been demonstrated in both laboratory and clinical studies; however, complete ruptures heal less consistently and may result in persistent instability. When operative intervention is deemed necessary, anatomical medial knee reconstruction is recommended.

Post-operative rehabilitation focuses on early motion and the return of normal neuromuscular firing patterns with progression based on attainment of specific phase criteria and goals. The purpose of this clinical commentary is to discuss the determinants of phase progression and the importance of objectively assessing readiness for advancement that is consistent with post-operative healing. Additional tests and validated measures to assess readiness for sport are also presented.

Key words: Medial periodization.

knee, medial collateral ligament, reconstruction, rehabilitation, return to sport,

Level of Evidence: 5

1

Massachusetts General Hospital, Boston, MA, USA Howard Head Sports Medicine, Vail, CO, USA 3 Steadman Philippon Research Institute, Vail, CO, USA 4 The Steadman Clinic, Vail, CO, USA 2

Financial Disclosure and Conflict of Interest: I affirm that I have no financial affiliation (including research funding) or involvement with any commercial organization that has a direct financial interest in any matter included in this manuscript, except as disclosed in an attachment and cited in the manuscript. Any other conflict of interest (i.e., personal associations or involvement as a director, officer, or expert witness) is also disclosed in an attachment.

CORRESPONDING AUTHOR Catherine A. Logan, MD, MBA, MSPT Massachusetts General Hospital 15 Fruit Street Boston, MA 02114 E-mail: calogan@partners.org 612-275-6924

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BACKGROUND AND PURPOSE The medial collateral ligament (MCL) is the most commonly injured ligament of the knee.1-3 The vast majority of significant MCL injuries occur secondary to a medially directed valgus force that is sustained just proximal or distal to the lateral knee joint.4 MCL injuries are more common in athletic cohorts compared to non-athletic cohorts, with the most injurious sports being collision and contact in nature. A greater risk of MCL injury is present in male athletes participating in intercollegiate as compared to intramural sports.5 A recent epidemiologic study of 346 MCL injuries in soccer players reported the average duration of time lost was 23.2 days, with higher grade injuries associated with greater lost time.6 Both laboratory and clinical studies have elucidated the healing capacity of the MCL complex; the MCL has the unique capability to heal with conservative measures in most cases.7,8 Non-operative treatment is often effective for grade I and II injuries, and can be effective in grade III injuries. The good healing potential of the MCL is secondary to the growth rate and functioning of its stem cells, as well as the expression of growth factors key to ligament healing.9-12

and, therefore, provides near normal ligament load distribution.17 Post-operatively, strict adherence to rehabilitation protocols is essential to enable optimal healing. A safe and effective rehabilitation protocol is informed by the existing literature, incorporating current rehabilitation principles, the science of soft tissue healing, and adaptations based on an individualâ&#x20AC;&#x2122;s readiness to progress through progressive phases. The purpose of this clinical commentary is to discuss the determinants of phase progression and the importance of objectively assessing readiness for advancement that is consistent with post-operative healing. Additional tests and validated measures to assess readiness for sport are also presented.

ANATOMY The primary structures of the medial aspect of the knee are the proximal and distal divisions of the superficial medial collateral ligament, the posterior oblique ligament, and the deep medial collateral ligament (Figure 1). The superficial MCL is the larg-

Both individual patient and biologic factors influence management of grade III tears. Pertinent patient factors to consider include timing of injury, level of activity, and presence of symptomatic instability. Injury location affects ligament healing; Frank et al13 reported slower healing and the development of abnormal morphology with insertional injuries as compared to midsubstance tears in a rabbit model.

Wilson et al14 reported complete injuries where the MCL is avulsed from the tibial insertion failed to heal reliably in the athletic population.

A keen understanding of knee anatomy, involved structures and potential for healing are necessary to make informed management decisions regarding the surgeonâ&#x20AC;&#x2122;s recommendation for surgical versus non-operative management of isolated grade III MCL injuries. If operative management is indicated, anatomic repair or reconstruction is recommended to improve overall patient function and to restore valgus stability.15,16 Anatomic medial knee reconstruction restores near native stability to the knee

Figure 1. Photograph of a knee, demonstrating the VMO, MPFL, AT, MGT, and sMCL. VMO, vastus medialis oblique; MPFL, medial patellofemoral ligament; AT, adductor tubercle; MGT, medial gastrocnemius tendon; sMCL, superďŹ cial medial collateral ligament.

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est structure of the medial aspect of the knee, and is comprised of one femoral and two tibial attachments.18,19 The central arm of the posterior oblique ligament is a fibrous extension off the distal aspect of the semimembranosus, which reinforces the posteromedial aspect of the joint capsule. The deep MCL comprises the thickened joint capsule deep to the superficial MCL, and is divided into meniscofemoral and meniscotibial components. The MCL is the primary stabilizer to resist valgus loading and has been shown to contribute 78% to the restraining force on the medial side of the knee.20,21 Resistance to valgus instability is secondarily provided by the ACL.22 The MCL and the posterior oblique ligament also contribute to resisting abnormal external tibial rotation.20,21 A controlled laboratory study investigating the structural properties of the medial knee ligaments found the superficial MCL had the highest load to failure and stiffness, followed by the posterior oblique ligament (POL) and deep MCL.23 The distribution of strain changes with flexion angle; Gardiner et al,24 in his cadaveric study measuring strain on the MCL during valgus loading, found the highest strain to occur at full extension on the posterior side of the MCL near the femoral insertion.

DIAGNOSIS Isolated injury to the medial knee ligament complex most commonly occurs due to a laterally directed blow just proximal or distal to the knee joint with the foot planted. Depending on the amount of knee flexion present at the moment of injury, some tibial rotation or translation may occur. Coupled forces, such as valgus stress and external rotation, may result in damage to both the MCL and posterior oblique ligament.25 After an MCL injury, patients often describe feeling instability with side-to-side activities, particularly with cutting or pivoting maneuvers. Physical examination, including visual inspection, palpation and the application of valgus load in both full knee extension and 20 to 30 degrees of knee flexion, is the initial step of the diagnostic process. The degree of medial joint opening relative to the unaffected knee allows the examiner to assess injury to the MCL. The valgus stress test at zero degrees, assesses for a combined medial knee and cruciate injury; asymmetric opening in full extension indicates a combined

injury to the MCL and posterior oblique ligament, and possibly the cruciate ligaments.26 Stability in full extension denotes no substantial damage to the posterior oblique ligament.27 Additionally, assessment of end-point integrity is utilized to determine the presence of an incomplete versus complete rupture.28 A valgus stress at 20-30 degrees of knee flexion is the primary test to evaluate for medial-sided ligament knee injury.

IMAGING Correlation of valgus stress radiographs with medial knee ligament injuries has been performed,29 and deemed to provide objective and reproducible measurements of medial compartment gapping. In one study, when a clinician applied valgus load to a knee with a simulated isolated grade-III superficial MCL injury, medial gapping increased by 1.7 and 3.2 mm at 0 and 20 degrees of flexion, respectively, compared to that of an intact knee. A complete medial knee injury, including the superficial and deep MCL and posterior oblique ligament, increased gapping by 6.5 and 9.8 mm at 0 and 20 degrees, respectively, under the clinician-applied valgus load. The authors reported intraobserver repeatability and interobserver reproducibility with intraclass correlation coefficients of 0.99 and 0.98 in the measurement of medial gapping. In addition to the diagnostic process, valgus stress radiographs are useful for preoperative planning and post-operative follow-up of patients.29 Magnetic resonance imaging (MRI) may be useful to determine both the location and the magnitude of ligamentous damage, as well as other injuries to the knee.

GRADING Isolated medial knee injuries have been classified by the amount of subjective laxity detected at 30 degrees of knee flexion with application of valgus load; however, it is required that the patient is able to relax during testing in order to accurately assess ligamentous integrity. Grades 1, 2, and 3 MCL injury correspond to perceived gapping of the medial joint line of 3 to 5 mm, 6 to 10 mm, and >10 mm, respectively.2,28 However, as noted above, these reported measurements for the grades of medial joint gapping are subjective amounts of the medial joint line gapping and do not correlate to that objectively mea-

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sured on stress radiographs. The American Medical Association Standard Nomenclature of Athletic Injuries30 has developed a widely utilized scale to grade medial knee injuries. An isolated grade I, firstdegree tear presents with localized tenderness without laxity. An isolated grade II, second-degree tear presents with localized tenderness and partially torn MCL and POL fibers. An isolated grade III, thirddegree tear presents denotes complete disruption of all three structures and no end point to valgus laxity testing.

POST-OPERATIVE REHABILITATION & RETURN TO PLAY AFTER MCL RECONSTRUCTIONS The post-operative rehabilitation protocol for grade III MCL injuries employed at the authors’ institution emphasizes early motion and restoration of neuromuscular firing patterns (see Appendix 1). Early motion, control of knee joint swelling and pain, and activation of the quadriceps during the initial recovery period after an anatomic knee ligament reconstruction is critical for overall recovery.31,32 After the initial period of non-weight bearing for 6 weeks in a hinged brace locked in extension when not working on knee motion in therapy, emphasis is placed on restoration of a proper gait pattern, functional exercise progression and the implementation of neuromuscular and proprioceptive-based exercises.31-33 The presence of concurrent cruciate ligament reconstructions or osteotomies may require significant modifications to the rehabilitation protocol in order to facilitate adequate soft tissue and/or bony healing.

Therapeutic Modalities Proposed benefits of cryotherapy include the promotion of local vasoconstriction to control edema, as well as the reduction of pain.34-36 Most recommendations for the use of cold therapy are based on anecdotal experience, with limited scientific evidence to support the efficacy of specific cold modalities. Hubbard et al37 conducted a systematic review investigating the impact of cryotherapy on soft tissue injury and found cryotherapy to be effective in decreasing pain in the acute setting. Malanga et al36 conducted a review of multiple cryotherapies in the setting of low back pain and found cryotherapy to be effective for short-term reduction in pain.

Active compression cold therapy devices, such as the Game Ready® system (Game Ready®, Concord, Georgia, U.S.A.) are commonly employed postoperatively to reduce pain and swelling. In a prospective randomized study38 examining continuous long-term application of an active compression cold therapy system after anterior cruciate ligament reconstruction and the authors found significantly increased range of motion and functional knee scores when compared to cold therapy alone.

Stockle and colleagues39 compared the impact of intermittent impulse compression (an air pad under the foot inflated every 20 seconds), standard cool packs, and continuous cryotherapy (ice water circulating between the ice box and the cold pad, with ice water was changed once per day) on edema in the treatment of acute foot and ankle trauma. The authors reported reduction in swelling by 74% with intermittent compression versus 70% with continuous cryotherapy and 45% with cool packs after four days of treatment. In the authors’ treatment protocol, patients utilize a Game Ready® on low compression for 30 minutes followed by 60 minutes off to allow for skin temperature recovery, with this cycle repeated a minimum of four times per day.

Bracing Post-operatively, the brace is set at full extension for six weeks with the exception of during passive range of motion with the physical therapist until appropriate quadriceps control is achieved. In this initial phase, an emphasis is placed on achievement of full extension and 90 degrees of knee flexion by the end of the first two weeks. After two weeks, knee motion is increased as tolerated. Loss of preinjury range of motion has been found to be one of the most frequently reported complications following knee ligament reconstruction surgery.40 After the six-week protection period, and in conjunction with the patient being able to clinically demonstrate active quadriceps control during terminal extension, in addition to passive knee flexion greater than 90 degrees, a transition to a return to sport brace is made. A timeframe for discontinuing all brace use is patient dependent and variable, with the decision being informed by consideration of environmental risk factors, athletic/work demands and physiological healing times.

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Table 1.

ROM/Muscular initiation

Time/reps + sets

Frequency

Wall slides- for repeated passive flexion and extension

10 min

3x/day

Seated flexion at end of bed (if unable to wall slide)

10 min

3x/day

Patellofemoral mobilization

10 min

3x/day

Quad sets

3 x 15

3x/day

Hamstring sets

3 x 15

3x/day

Stationary bike - no resistance, starting at week 7

10 min

2x/day

Table 2.

Muscular endurance

Sets

Reps

Rest

Double leg leg press+

3

15

45s

Static lunge hold

3

maximum

45s

Single leg deadlift+

3

15

45s

Squat progression-body weight a) Double leg squat b) Double leg squat to calf raise c) Double leg squat to weight shift and hold on affected leg

3

30

45s

Tuck squat

3

maximum

45s

Double leg bridge

3

15

45s

+

Patient-specific levels of resistance are added to exercises as appropriate, to allow for completion of the outlined exercise parameters and maximal development of the desired physiological characteristic.

Weight Bearing Progression A period of non-weight bearing is recommended immediately following surgery.2,14,41 After six weeks of protected weight bearing; a program that focuses on increasing the patientâ&#x20AC;&#x2122;s weight bearing tolerance is implemented. This period of progressive weight bearing is designed to incrementally increase loading volume to reduce the risk of a rehabilitation setback through overloading the joint and reconstructed/repaired structures.16 Options to increase patient tolerance to weight bearing include resisted biking, walking in a pool, or walking on an anti-gravity treadmill. Once full weight bearing is achieved comfortably, the rehabilitation provider should focus on restoration of a normal gait pattern. The quadriceps muscle is typically atrophied42 and inadequate quadriceps strength contributes to altered gait patterns following knee surgery.43 Persistent intra-articular effusion may contribute to quadriceps

inhibition, loss of range of motion, joint pain, and gait abnormality.44 Notable reduction in quadriceps electromyographic activity occurs with as little of 10 mL of intra-articular fluid.42 Caution to avoid a valgus moment at the knee joint during stance phase, which can occur in an attempt to unload the knee joint by posting the foot of the surgically treated extremity lateral to the base of support.28 Progression of exercises is not permitted if the patient is unable to ambulate without a limp to ensure that increasing activities does not result in abnormal forces on the reconstruction grafts.

Immediate Range of Motion Long periods of immobilization after anterior cruciate ligament reconstruction have been replaced by accelerated protocols to improve functional outcomes.45-47 Similarly, immediate range of motion is recommended following medial knee reconstruc-

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tion. Animal studies have examined the metabolic and cellular effects of immobilization on the collateral ligaments and their authors have reported a detrimental impact on cellular metabolism.48,49 Another animal study evaluating the vulnerability of ligament grafts to creep assessed thirty-nine MCL autografts in a rabbit model with nineteen of the rabbits being immobilized post procedure. The authors of the study revealed that immobilization resulted in increased vulnerability of the ligament autografts to creep, postulating that following immobilization the increase in magnitude of susceptibility to creep will result in functionally significant elongation of the graft if exposed to higher tensile loads and over longer periods of time in vivo.50 Thornton et al51 also assessed the creep and creep recovery of fresh anatomic ligament autografts in an extra-articular environment using a rabbit model. The immobilized grafts (duration of immobilization, six weeks) had significantly greater creep compared to non-immobilized grafts at one year of healing (p < 0.05).

A safe range of motion which promotes joint mobility, yet protects the healing soft tissue graft, should be determined intra-operatively by the treating surgeon, and then communicated to the rehabilitation provider to ensure appropriate range of motion parameters immediately post repair or reconstruction.52 Knee stiffness after medial-sided repair or reconstruction is a known complication; therefore, initiation of passive ROM exercises is necessary to avoid capsular adhesion formation.2,28 Preferably, immediate passive range of motion is recommended to minimize the risk of arthrofibrosis,41 with the goal of attaining 0 to 90 degrees at two weeks post-operatively. Noyes et al53 found immediate passive range of motion following open and arthroscopic anterior cruciate ligament reconstruction surgery did not increase joint effusion, hemarthrosis, or soft tissue swelling; however, aggressive range of motion exercises should be avoided the first three weeks post-operatively to avoid placing tension on the reconstruction.53 After the two-week mark, range of motion should be progressively increased as tolerated with the goal of 130 degrees of passive knee flexion at six weeks post-operatively. Early knee motion has not been found to result in stretching of the graft, based on

post-operative stress radiographs.16 Of note, even minor deficits in knee flexion and extension ROM are not well tolerated in athletes, as these limitations can negatively affect muscular strength development, impacting running, agility and jumping performance. Deficits larger than ten degrees of knee flexion have been associated with running speed reduction.54,55 Adhesion formation in the suprapatellar pouch and anterior interval can limit joint range of motion and increase joint contact pressures.56 For this reason, mobilization of the patellofemoral joint should be initiated immediately post surgery and continued for six weeks.

Phases of Rehabilitation Progression The outlined rehabilitation protocol time points are provided as a guideline for phase progression; however, true readiness for phase advancement should be determined by achievement of the goals provided for each phase of rehabilitation (Appendix 1). Progression of exercises is not permitted at the authorsâ&#x20AC;&#x2122; institution if the patient has a persistent limp or gait abnormality to ensure advancing activities does not result in recurrent joint effusion. All exercises should be conducted under careful supervision and monitoring of proper lower extremity kinematics and alignment. Recurrent or persistent pain and swelling indicate improper phase progression.

Additional measures and tests are included in the phase progression criteria. A large array of measures and tests are available, with the following chosen for their clinical utility, ease of administration and interpretation; the quadriceps index, the Y-Balance Testâ&#x201E;˘ (YBT), the Vail Sport Testâ&#x201E;˘, the modified agility T-test, and the single leg hop series. The quadriceps index is a measure of the relative isometric strength of the involved quadriceps in comparison to the uninvolved quadriceps and expressed as a percentage. Strength measurements are captured using a handheld dynamometer positioned on the distal tibia with the patient seated on the end of a treatment table with this hip and knee angle at 90 degrees. The YBT is a functional test performed to evaluate functional symmetry and performance, as well as assess risk for injury (Figures 2a, 2b). Performance of the YBT requires lower extremity and trunk/core strength, flexibility, neuromuscular con-

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Figure 3A, 3B. The Vail Sport Testâ&#x201E;˘, a return to sports assessment that incorporates a series of dynamic multiplanar functional activities against the resistance of a sports cord.

Figure 2A, 2B. The Y-Balance Testâ&#x201E;˘ (YBT), a functional test performed to evaluate functional symmetry and performance, as well as assess risk for injury.

trol, range of motion, balance and proprioception, and can be performed relatively efficiently. The Vail Sport Testâ&#x201E;˘ is a return to sports assessment that incorporates a series of dynamic multiplanar functional activities against the resistance of a sports cord (Figures 3a, 3b). The modified agility T-test focuses on identifying side-to-side deficits in multiplanar cutting and agility tasks (Figures 4a, 4b), while the single leg hop series is a commonly employed performance measure used to analyze limb symmetry and functional performance following knee surgery (Figures 5a, 5b).

Muscle Initiation, Endurance, Strength, and Power Quadriceps activation via quadriceps setting exercises, straight leg raises in the brace, hip extension and hip abduction exercises are encouraged imme-

diately after surgery. Quadriceps activation is particularly important to combat the marked weakness of quadriceps muscles typically observed after knee surgery.42,57 Once the post-operative effusion has resolved, knee motion is greater than 115 degrees, the patient is full weight bearing without crutches, and straight leg raises can be performed without an extension lag, the patient may commence CKC strengthening. Progression of strengthening exercises, both in their mode and complexity, is dependent on many factors. The post-operative rehabilitation protocol outlined in Appendix 1 includes a suggested timeline, general goals for each phase, precautions to maintain, specific exercises to perform, and criteria for advancement to the next phase of rehabilitation. Worthy of inclusion, as well, is an overview of the guidelines on the resistance training variables.

Traditional rehabilitation programs utilize basic progressive overload principles (stress to the muscle is progressively increased as it becomes capable of

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Figure 4A, 4B. The modiďŹ ed agility T-test focuses on identifying side-to-side deďŹ cits in multiplanar cutting and agility tasks.

Figure 5A, 5B. The single leg hop series, a commonly employed functional performance measure used to capture limb asymmetries following knee surgery.

producing greater force, power, and endurance), however, the application of periodization in rehabilitation protocols has also been proposed.58

ticular duration of time. The overall goals are similar in both programs. There is a paucity of data in rehabilitation research, however, in healthy trained and untrained athletes periodized strengthening programs elicit greater strength gains than non-periodized programs,58 and have been shown to be a safe method in older adults and those with pain.58,60

Periodization is defined as the planned manipulation of training variables (load, sets, and repetitions) to maximize training adaptations and prevent the onset of overtraining,59 with the goal of optimizing the neuromuscular systems to adapt to unaccustomed load or stressors. Lorenz and colleagues58 described both linear and nonlinear periodization protocols following anterior cruciate ligament reconstruction, which have been adapted and integrated into the post-operative rehabilitation protocol for grade III medial collateral ligament injury. In a linear program, phases depend on the time frame of rehabilitation, while a nonlinear program allows for increased flexibility by the treating physical therapist. Nonlinear programs permit the clinician to alter intensity, volume and training focus (endurance, strength, power) for a par-

In addition to lower extremity strengthening, emphasis on proximal strength and core stability is necessary to promote appropriate joint reaction forces at the knee. Noehren et al,61 in their analysis of hip and trunk neuromuscular control, found patients who underwent anterior cruciate ligament reconstruction had significantly greater trunk ipsilateral lean, forward lean, and higher errors on trunk stability testing compared to healthy controls.

The average time between reconstruction and testing was 222.2 +/- 44 days. Further, weakness in hip abduction during dynamic activities can place a val-

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Table 3.

Muscular strength

Sets

Reps

Rest

Single leg leg press+

3-4

12

2min

Reverse lunge with dumb bells+

3-4

12

2min

Single leg squat

3-4

maximum

2min

Single leg deadlift with kettle bells+

3-4

12

2min

Balance squat with dumb bells+

3-4

12

2min

Crab walk with resistance band+

3-4

maximum

2min

Patient-specific levels of resistance are added to exercises as appropriate, to allow for completion of the outlined exercise parameters and maximal development of the desired physiological characteristic

Table 4.

Muscular Power Single leg leg press

Sets +

Reps

Rest

3

8

3min

Reverse lunge into hip drive

3

8

3min

Lateral agility with sports cord

3

60s

3min

Bulgarian jump squat

3

8

3min

Double leg 8 inch box jump up

3

8

3min

ROM= Range of motion, min= minutes, s=seconds. +Resistance is increased for single leg leg press beyond that performed in the muscular strength phase. By increasing exercise intensity, the desired physiological characteristic is maximally developed

gus stress across the knee, excessively loading the reconstructed complex.62 Core stability training has also been shown to result in a significant reduction in strength asymmetries during jump testing.63 Neuromuscular Reeducation Mechanoreceptors within the ligament and joint capsule are damaged with medial sided ligament injury, and knee proprioception is reduced, hampering response to perturbations.64 Balance and proprioception exercises should begin shortly after full weight bearing,65 initially with bilateral upper extremity support. Lower extremity proprioception and balance activity progression includes single-leg exercises, followed by the inclusion of less stable surfaces. Finally, dynamic, multi-directional drills are implemented.

Throughout the progression, strict attention to lower extremity alignment is emphasized, with special

attention on the avoidance of a valgus moment at the knee.

Return to Jogging, Plyometric & Agility Training Once the patient achieves appropriate lower extremity strength, range of motion and proprioception, as outlined in the simple measures reported below, a running progression program may begin. Patients must demonstrate good control in concentric and eccentric phases during strength training exercises and preserve proper lower extremity alignment during neuromuscular reeducation drills, which generally occurs between sixteen and twenty weeks post-operatively. Readiness may be determined with two simple tests; the patientâ&#x20AC;&#x2122;s ability to tolerate one to two miles of brisk walking without a limp and demonstrate balance and control while performing a

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single-leg squat to approximately 90 degrees of knee flexion.28,66 The single-leg squat test is a reliable tool to evaluate frontal plane motion of the knee and is a valid clinical measure to assess lower extremity movement quality.67 Readiness for body weight plyometric and agility exercises is determined by comparison of strength and functional hopping. Initially, basic double-leg plyometric drills are recommended, followed by progression to single-leg activities and more challenging, dynamic drills. Upper extremity support or modifications may be utilized to assist transition to more difficult exercises. The patient must achieve 75% of quadriceps strength and, on the functional hop test, score >75% relative to the unaffected side.19 Attention to landing mechanics is of particular importance during plyometric and jumping exercises to avoid excessive valgus forces through the knee joint. Well-studied in the setting of anterior cruciate ligament reconstruction, poor landing technique has been attributed to secondary tears.68-71 Sufficient hip and core strength is required to maintain proper landing kinematics.62 Return to Play Multiple patient factors are considered prior to an athlete’s return to play, including their recovery of strength compared to the contralateral lower extremity, clinical and objective knee stability, and desired activity or sport. At approximately twenty weeks post-operatively, an assessment of readiness to return to full activity can be conducted. Assessment may be performed with sport-specific functional tests, such as the Vail Sport TestTM; however, no single test exists to meet the functional and activity needs of each patient, necessitating an individualized approach by the treating surgeon and the rehabilitation provider. Preferred sport or activity is influenced by geography; for example, flat land versus mountain-based activity, and the demands these activities place on the operative extremity must be considered. Further, functional testing provides an inaccurate marker for risk of injury because tests are performed under non-fatigued conditions.72 Fatigue protocols may be introduced to return to sport tests, realizing the difficultly replicating the fatigue experienced in a competition or performance-based environment. A return to full activity is appropri-

ate when the patient can demonstrate appropriate strength on functional testing and proper alignment and control with dynamic activities, as well as objective knee stability on clinical examination. Repeat valgus stress radiographs may be obtained to further confirm stability.

SUMMARY The vast majority of MCL injuries may be managed non-operatively, however, a select group of patients who sustain MCL complex injuries benefit from operative intervention, specifically anatomic repair or reconstruction. Successful return to activity relies on strict adherence to the post-operative rehabilitation protocol. The authors’ rehabilitation protocol has been provided that is informed by available scientific evidence and is responsive to an individual’s ability to safely advance through rehabilitation phase progressions.

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APPENDIX 1

The International Journal of Sports Physical Therapy | Volume 11, Number 7 | December 2016 | Page 1190

IJSPT

CLINICAL COMMENTARY

CLINICAL COMMENTARY ON MIDFOOT AND FOREFOOT INVOLVEMENT IN LATERAL ANKLE SPRAINS AND CHRONIC ANKLE INSTABILITY. PART 2: CLINICAL CONSIDERATIONS John J. Fraser, PT, MS, OCS1, 2 Mark A. Feger, PhD, ATC3 Jay Hertel, PhD, ATC1

ABSTRACT Lateral ankle sprains (LAS) and chronic ankle instability (CAI) are common musculoskeletal injuries that are a result of inversion injury during sport. The midfoot and forefoot is frequently injured during a LAS, is often overlooked during clinical examination, and maybe contributory to the development of CAI. The purpose of part two of this clinical commentary and current concept review is to increase clinician’s awareness of the contribution of midfoot and forefoot impairment to functional limitation and disability of individuals who experience LAS and CAI and to facilitate future research in this area. The importance of multisegmented foot and ankle assessment from a clinical and research perspective is stressed. Select physical assessment and manual therapeutic techniques are presented to assist the clinician in examination and treatment of the ankle-foot complex in patients with LAS and CAI. Keywords: Gait, intrinsic foot muscles, joint mobilization, physical examination, rehabilitation

1

Department of Kinesiology, University of Virginia, Charlottesville, VA, USA 2 US Navy Medicine Professional Development Center, Bethesda, MD, USA 3 Virginia Commonwealth University School of Medicine, Richmond, VA, USA Conflicts of Interest: None Disclosures: The views expressed in this article are those of the author(s) and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense, or the United States Government. Lieutenant Commander John J. Fraser is a military service member and this work was prepared as part of his official duties. Title 17, USC, §105 provides that ‘Copyright protection under this title is not available for any work of the U.S. Government.’ Title 17, USC, §101 defines a U.S. Government work as a work prepared by a military service member or employee of the U.S. Government as part of that person’s official duties.

CORRESPONDING AUTHOR John J Fraser, PO Box 400407, Memorial Gymnasium, Charlottesville, VA Phone: 757-438-0390 E-mail: jjf5ac@virginia.edu

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BACKGROUND AND PURPOSE In the first part of this clinical commentary and current concepts review, foot and ankle anatomy, the roles of the intrinsic and extrinsic foot and ankle musculature from a multisegmented foot perspective, and the biomechanics of the ankle-foot complex during function were examined.1 In part two of this this commentary, the contribution of midfoot and forefoot impairment in lateral ankle sprains and chronic ankle instability will be discussed in order to increase clinician’s awareness and to facilitate future research in this area. The importance of multisegmented foot and ankle assessment will also be discussed from a clinical and research perspective.

Lateral ankle sprains (LAS) are common musculoskeletal injuries that affect more than two million individuals annually in the United States.2 Only 11% of LAS patients perform supervised physical therapy following their injury.3 Improper management of LAS may manifest into the residual impairment seen in the 40% of LAS patients that develop chronic ankle instability (CAI).4 CAI is a chronic condition that involves impaired neuromuscular control, residual instability, and chronic pain that collectively result in self-reported disability after LAS.5–8 Kinematic analyses of acute LAS’s sustained during sport demonstrate rotational velocities up to 2124°/second which leads to extremes of range of motion, including up to 52° of plantarflexion, 126° of inversion, and 99° of adduction.9–13 Simulated ankle sprains have demonstrated external moments in excess of 23 Nm for inversion and 11 Nm for adduction in simulated Grade I sprains.14 LAS commonly involves damage to the anterior talofibular and calcaneofibular ligaments, which can be strained to approximately 20% and 16% of their resting length, respectively.14,15 Søndergaard16 demonstrated that both the midfoot and forefoot are frequently injured during inversion ankle sprains and this phenomenon may be underappreciated by many clinicians. A number of midfoot injuries share similar mechanics to those incurred during a LAS.17–24 Figure 1 depicts the external adduction and inversion moments that create lateral midfoot adduction stress and rearfoot inversion stress incurred during an inversion injury. The occult presentation of mild to moderate midfoot injury is likely attributed to the synchronicity of lateral

Figure 1. Lateral midfoot stress due to external adduction and inversion moments during an inversion injury.

ankle and midfoot injury. Inversion injuries frequently cause damage to the soft tissue structures of both the ankle and midfoot, while pain is often localized to the talocrural or subtalar articulations.16 Nevertheless, if a patient reports inverting or ‘rolling’ their ankle, a thorough assessment of the lateral ankle joint and foot should simultaneously be performed. A recent clinical practice guideline published by the Orthopaedic Section of the American Physical Therapy Association recommends assessing patients who sustain LAS for painful foot conditions that may be indicative of fracture, cuboid involvement, or midfoot disruption.25 Despite improved understanding of the pathomechanics and pathophysiology of LAS and CAI, there is no evidence that the rate of recurrent LAS or CAI is declining. There is a need for further examination of other potential contributors to the etiology of recurrent LAS and CAI. Consideration of midfoot and forefoot involvement after LAS may be of clinical importance and the purpose of Part 2 of this clinical commentary and current concepts review paper is to increase clinicians’ awareness of the contribution of midfoot and forefoot impairment to activity limitation and participation restrictions of individuals who experience LAS and CAI and to facilitate future research in this area. To accomplish this, the importance of multisegmented foot and ankle assessment from a clinical and research perspective will be reviewed.

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INJURIES INVOLVING THE MIDFOOT AND FOREFOOT Midfoot Injury Midfoot injuries may include fractures, dislocations, subluxations, ligamentous sprains, or a composite of one or more of these injuries and are named by mechanism vector of the injurious force.26,27 Examination of the foot is indicated when there is an apparent osseous or ligamentous injury in the foot. Prudence may dictate that the foot is examined in conjunction with the ankle following inversion injury, even when the patient does not report symptoms. The mechanism of midfoot injuries are frequently a consequence of ankle and foot supination that result in deleterious dorsal translation/axial compression in the medial column and plantar translatory/tensile distractive forces in the lateral column.28 These injurious forces may culminate in ligamentous tears and osseous avulsions at the attachments of the calcaneocuboid, talonavicular or bifurcate ligaments.16 Midfoot Injury in Lateral Ankle Sprains In a prospective study of 711 patients who sustained an inversion sprain and were diagnosed in an urgent-care clinic, isolated midfoot sprains of either the bifurcate/ dorsal calcaneocuboid ligament, talonavicular ligament, or both were found in 172 (26%) of the cases.16 Additionally, midtarsal joint capsule involvement was found in 237 (33%) individuals who sustained LAS.16 In another study investigating midfoot involvement in patients with history of LAS, damage to the bifurcate ligament was found in 40.5% of all cases.29 Of these patients, 23% of the patients who had a diagnosis of “lateral ankle sprain,” had isolated bifurcate ligament injury and an intact lateral ankle.29 These findings illustrate that midtarsal joint injury is quite common, may mimic or contribute to lateral ankle signs and symptoms, and that the foot should be thoroughly examined following inversion ankle-foot injury. Because midtarsal joint injury may be misdiagnosed as a LAS, delay of care or improper clinical management may contribute to persistent activity limitation and participation restriction in these patients.

Cuboid Syndrome Cuboid syndrome, a lateral midfoot injury as a result of minor disruption of the calcaneal-cuboid congruency, has been described as being caused by abnormal inversion forces acting on the rearfoot when the fore-

foot is loaded during weight bearing.17 Newell and Woodle30 and Marshall31 have described cuboid syndrome as a partial dislocation of the cuboid with subsequent impairment in motion. Similar mechanics have been described in multiple case studies of cuboid dislocation, a related and clinically more severe disruption of the calcaneocuboid articulation.18–24,32 Analyses of case history and post-injury imaging have supported that when the forefoot is supinated, insult incurred from a dorsolateral external moment directed to the lateral aspect of the midfoot creates a plantar-medial displacement of the cuboid on the calcaneus.18–24,32 It has been theorized that cuboid syndrome results from a calcaneocuboid subluxation created by forceful fibularis longus contractions during inversion injury.33 The cuboid is normally everted and compressed during contraction of the fibularis longus as it courses around the fibularis sulcus.34 During the combination of rearfoot inversion during forefoot loading, a medial and dorsal force vector created by the fibularis longus exerted on a medially rotated cuboid causes an inferomedial subluxation33 (Figure 2). The subsequent discomfort associated with cuboid syndrome is attributed to the malposition of the cuboid and subsequent irritation of the joint capsules, ligaments, and the fibularis longus tendon.17 Chronic Ankle Instability and the Multisegmented Foot Many individuals who sustain LAS will subsequently develop persistent pathological gait kinematics35–39

Figure 2. Cuboid eversion with fibularis longus contraction.

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and altered motor strategies37,40–42 associated with CAI. CAI occurs in individuals that have had at least one significant ankle sprain, have repeat episodes of giving way, feelings of instability, or recurrent ankle sprains, and self-reported disability as a result of the ankle injury.5 Groups of patients with CAI have been observed to walk with a wider bases of support,43 decreased stride to stride variability in shank-rearfoot coupling,38 increased shank external rotation excursion,39 a more plantarflexed35 and supinated foot,37,39 and a more lateral center of plantar pressure progression41,42,44–46 when compared to healthy controls. They have greater electromyographic activity for longer period of time in the gluteus medius and medial gastrocnemius pre initial contact (IC),42 fibularis longus immediately pre36,37,41,42 and post36,37,41 IC, and gluteus medius from 50% of stance phase to 25% of swing phase.42 Evidence is conflicting regarding the electromyographic activity in the tibialis anterior during the stance phase of gait, with both increased41 and decreased42 activity reported. Impairment in the midfoot47,48 and medial forefoot kinematics49 have been suggested to be contributory in CAI. Interestingly in a study of 711 patients who sustained inversion injury isolated to either the lateral ankle (65% of sample) or the midtarsal joint (23% of sample), pain, swelling, perception of giving way, and subsequent inversion injury persisted at the same frequency at 6-12 months regardless of the site of injury.16

following IC when compared to healthy controls, which has been suggested to be a contributing factor to this population’s increase risk for reinjury.36,37 Morphologically a group of patients with CAI who were scheduled for lateral ankle reconstruction were found on radiograph to have significantly higher mean talometatarsal and talocalcaneal angles, and lower mean calcaneal angles and tarsal indices when compared to healthy controls, indicating higher medial longitudinal arches and cavovarus.52 It has been suggested that cavovarus in patients with CAI is a major contributing factor in the progression to ankle osteoarthritis and corrective calcaneal osteotomy should be considered in conjunction with ligamentous reconstruction to normalize forces about the ankle-foot complex.53

In order to make the case of suspected midfoot involvement in CAI, there are some recent studies in healthy subjects that may provide some contrast and relevance. A study of healthy individuals who were classified as having a large inversion forefoot angle at IC (5.9 ± 1.6°) were found to have a greater forefoot pronation excursion and remain everted for longer periods during stance when compared to a group who had a moderate forefoot angle (2.6±1.1°) at IC.50 Similarly, the findings of a kinematic study of the rearfoot coupling mechanism were that healthy midtarsal joints uncoupled from the rearfoot post IC and remained unlocked through terminal stance. 51 This finding challenges the notion that the midtarsal joint locks the rear and midfoot at terminal stance in order to provide a rigid lever required for efficient gait.

Changes in plantar pressure during walking have been found in patients with CAI when compared to healthy controls.41,44–46,54 Nyska and collegues45 found patients with CAI spend more time in the rear and midfoot during stance with a delay in transition to the central and lateral forefoot and toes, increased pressure in the midfoot and lateral forefoot, and decreased pressure in the heel and toes. Schmidt and colleagues46 also found a delay in time to peak pressure of the medial and lateral rearfoot and the medial midfoot during early stance phase in patients with CAI. Patients with CAI have greater plantar pressure under the midfoot and lateral forefoot and decreased pressure in the heel and toes compared to healthy controls.45,46 Nawata and colleagues44 found that patients with CAI ambulated with a laterally deviated center of progression and an adducted/ supinated foot during midstance. Hopkins and colleagues41 observed similar findings with subjects with CAI walking with increased lateral center of pressure progressions between 20% to 90% of stance when compared to healthy matched controls. Koldenhoven and colleagues42 found that patients with CAI have a more lateral center of pressure progression throughout the stance phase and have increased plantar pressure in the lateral forefoot for longer periods of time. Individuals with CAI also run with a lateral plantar pressure distribution during foot strike and the plantar progression starts more laterally during initial loading when compared to controls.54

Groups of patients with CAI have been found to have up to 7° more inversion in the rearfoot prior to and

The kinematic and kinetic findings found in patients with CAI may result from the impaired ability to

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uncouple the midfoot from the rearfoot due to mechanical or neurophysiologic constraints. Impaired joint mobility in any of the foot segments may impair the ability of the foot to decouple during lower velocity ambulation. A neurophysiologically constrained midfoot combined with a supinated rearfoot could plausibly contribute to the lateral shift in plantar center of pressure progression during the stance phase of gait. Joint mobility assessment and manipulation has been recommended in clinical cases of idiopathic cavovarus, especially when associated with gait abnormalities and clinical entities such as LAS and ankle instability.55 Hypomobility of the first ray may contribute to the lateral shift in plantar pressure seen in this patient population.56 It is plausible that joint hypomobility could also affect the muscles acting on the first ray and may explain the findings of a recent study, where patients with CAI were found to have atrophy of the flexor hallucis brevis and flexor hallucis obliquus and hypertrophy of the flexor hallucis longus.

Neuromuscular adaptations in the foot such as cocontraction of the extrinsic and intrinsic antagonistic pairs may also be implicit in CAI. Increased muscle stiffness is thought to be beneficial in joint stability, especially when mechanical stability is impaired and the muscles play a larger role in mitigating destabilizing forces.57 If there is mechanical disruption of the transverse tarsal, tarsometatarsal, or intertarsal ligamentous structures, it is plausible that stabilizing co-contraction in the foot may create a situation where the rearfoot, midfoot, and forefoot remain coupled throughout stance, creating a constrained system.

Impaired coupling in the foot may also occur in the CAI population due to neuromuscular dysfunction of the extrinsic and intrinsic musculature. In electrophysiological studies of 66 patients who sustained LAS, Nitz and colleagues58 found decreased nerve conduction velocities in the peroneal (17% of patients with a Grade II LAS, 86% of patients with a Grade III LAS) and tibial (10% of patients with a Grade II LAS, 83% of patients with a Grade III LAS) nerves, as well as electromyographic evidence of denervation. Jazayeri and colleagues59 also found increased peroneal and tibial nerve latencies during nerve conduction studies of football (soccer)

players who sustained LAS. Impaired fibularis longus or intrinsic foot muscle function secondary to neuropraxia or traction axonotmesis/neurotmesis may be deleterious to intersegment coupling, foot shaping, intersegmental stability, force attenuation, and afferent feedback from the articular soft tissue and plantar cutaneous sensation. In the only study known to investigate individuals with CAI utilizing a multisegmented foot model during walking, the first ray was found to have a mean 9.4° more inversion from 87% to 98% of stance phase when compared to healthy controls.49 Similar findings were observed in LAS copers, operationally defined as subjects who had sustained LAS in the previous two years but were not experiencing ankle instability, had a mean 7.4° difference from 10% to 83% of stance phase.49 The fibularis longus, besides being an extrinsic evertor of the foot, is a plantarflexor and evertor of the hallux, and stabilizes the medial column, medial longitudinal and transverse arches60 and the calcaneocuboid joint.34 Impaired peroneal function has been offered as a possible explanation for the supinated position of the hallux in patients with CAI.49 Patients with CAI have been found to have decreased concentric and eccentric strength,61 diminished mean activation time,62 and increased latency and electromechanical delay63 in the fibularis longus in the injured limb when compared to healthy controls.

Due to the proximity of the fibularis longus to the cuboid, minor disruption in cuboid congruency or subluxation is thought to contribute to peroneal irritability64 and may contribute to impaired function of this muscle. The cuboid functions as a pulley for the fibularis longus tendon and provides a more advantageous vector of pull to support the transverse arch, medial longitudinal arch, and the first ray.60 More substantial disruption in stability or position of the calcaneus may have the potential to disrupt this pulley mechanism by altering tendon slack length or the vector of force. Patients with CAI have been found to walk at lower velocities43 and with an adducted foot.45 It is plausible that impaired ability to lock the midfoot due to ligamentous instability or neuromuscular impairment in the fibularis longus may force patients with CAI to employ a gait strategy where pushoff occurs about the oblique metatarsal axis.

This may also explain some of the plantar pressure findings found in the lateral forefoot in patients with

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Table 1. Observational and Clinical Measures of Foot Morphology.

CAI. This gait strategy may also be utilized to maximize balance in the presence of other neurophysiologic impairment.

CLINICAL IMPLICATIONS AND FUTURE DIRECTION The midfoot plays an essential role in force transmission during gait, is commonly injured during inversion sprains, and is likely to contribute to the morbidity associated with LAS and CAI. Clinically, it is important to consider the midfoot and forefoot during examination and treatment of these patients.

It has been previously suggested that the diagnostic scope should be widened to include the midfoot when assessing and treating common ankle sprains.16 Based on the evidence presented in this paper, it is recommended that patients may benefit from examination of the midfoot and forefoot post inversion injury, even when the patient does not report pain symptoms in the region. If treating providers fail to assess the midfoot and forefoot following LAS, it is likely that important contributory impairment will be missed.

The authors recommend that clinicians take a holistic approach when examining and performing treatment in those who sustain LAS. A detailed clinical history that captures type and duration of symptoms, recurrence, mechanism of injury, timing and location of pain complaints, and current functional limitations will help guide the physical examination. Inquiry to factors, that when implemented have been shown to hypertrophy the intrinsic foot muscles and beneficially modify foot shape, such as minimalist footwear65,66 time spent barefoot,67â&#x20AC;&#x201C;69 and the type of surface physical activity occurs (outdoors > indoors)67 may provide the clinician insight regarding intrinsic foot strength.

Observation of foot morphology, in both unloaded and loaded conditions, can provide information on the patientâ&#x20AC;&#x2122;s ability to shape and stabilize the foot.

Measurements of navicular height, dorsal arch height, foot length, and foot width in both loading conditions are expedient and clinically meaningful methods of assessing control of the longitudinal and transverse arches. Table 1 presents some suggested observational and clinical measures of foot morphology.

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Table 2. Joint Mobility Assessment of the Ankle-Foot Complex. Joints are graded as having normal mobility, hypermobility, or hypomobility

Palpatory examination of the joints, ligaments, and muscles of the foot is important post inversion injury to assist in determining midfoot or forefoot involvement. Joint range of motion and accessory motion assessment in each segment and joint of the

foot will often reveal intersegmental joint limitation and provide the clinician with a prime opportunity to render treatment such as joint mobilization or manipulation. Suggested manual therapeutic techniques for the ankle-foot complex are presented in

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Table 3. Joint Manipulation of the Midfoot and Medial Forefoot

Tables 3 and 4. In the cases of segmental instability, the plan of care can be modified to allow for protection, intervention such as taping/strapping, bracing, orthotic fitting, and foot core stabilization exercises, and/or referral to orthopedic surgery or podiatry for

surgical consideration. Table 2 presents some suggested joint mobility assessment techniques that can be used in the clinical examination.

Assessment of intrinsic muscle function can be difficult without the use of laboratory equipment or imag-

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Table 4. Joint Manipulation of the Rearfoot and Shank

ing modalities that are either not feasible or accessible for regular clinical use. Equipment such as motion capture systems, electromyographic, or magnetic resonance imaging machines is expensive, take clinical space, or require time-consuming technical analysis. Clinically, there are strategies that practitioners may use to objectively collect surrogate measures of intrinsic muscle function. The intrinsic muscles have been found to have the ability to control deformation of the longitudinal arch.70 Measurement of the navicular height, foot length, and width using a tape

measure or caliper in both unloaded position and in standing is a time expedient and inexpensive method.

Toe flexor strength has been found to be associated with cross sectional area of both the extrinsic and intrinsic foot muscles, with larger size of the medial plantar intrinsic foot muscles (flexor hallucis brevis, flexor digitorum brevis, quadratus plantae, lumbricals and abductor hallucis) being a major predictor of toe flexor strength.71 Manual muscle testing of the toe flexors is an easy and quick assessment technique that may yield clinically relevant information about

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the intrinsic foot muscles. Testing the patient’s ability to isolate great toe movements from the lateral forefoot (great toe abduction, great toe extension with flexion in toes 2-5, great toe flexion with extension in toes 2-5) and strength testing may yield pertinent information on intrinsic function.

Ultrasound imaging is a modality that has emerged in the literature for the assessment of intrinsic foot muscle size.72–76 Many clinicians have access to ultrasound imaging units, which makes this imaging modality ideal for use in evaluation of patients with ankle-foot pathology. Clinicians may find ultrasound imaging useful as an outcome measure for tracking changes in resting muscle size to assess effectiveness of exercise intervention (hypertrophy) or atrophy following disuse or neuromuscular insult. There is also great potential for the use of this imaging modality for the assessment of neuromuscular function or as a bio-feedback instrument.

Assessment of the intrinsic and extrinsic muscles of the ankle-foot during a state of contraction may provide a clinician great insight to neuromuscular function and motor control. Future research is needed to establish the measurement properties of ultrasonography for assessment of neuromuscular function of the intrinsic foot muscles.

Testing of extrinsic muscle function of the ankle-foot complex is a standard of care when treating patients with LAS or CAI. Commonly, assessment is comprised of manual muscle testing (MMT) or hand held dynamometry of the open kinetic chain motions of ankle dorsiflexion, plantarflexion, inversion, and eversion. While MMT is a convenient assessment technique that may reveal information about single segment, open kinetic chain function of the extrinsic muscles, they may not translate well to how these muscles function in relation to the multisegmented foot. It has been recommended that strength testing and training should be specific with consideration given to muscle group function and the joint segments the tendons cross.77 A more clinically relevant assessment of both the extrinsic and intrinsic muscles may be accomplished by testing their function in foot shaping, stability, and force attenuation.

For example, assessment of the patient’s ability to maintain arches across loading conditions may yield more clinically relevant information on the synergy

of the posterior tibialis and the intrinsic muscles to maintain the medial longitudinal arch in both conditions. MMT of first metatarsal plantarflexion and adduction may yield more pertinent information on fibularis longus function as opposed to standard testing of foot eversion. Once deficits are identified, treatment that is specific to the impairment may be implemented. Treatments such as strengthening exercises, neuromuscular stimulation, biofeedback, and gait training may be employed with progressive loading for isolation and integration of the intrinsic and extrinsic muscles.78 Video of some intrinsic foot exercises can be accessed at https://goo.gl/ugffZ8.

CONCLUSIONS In summary, the midfoot and forefoot are commonly injured and can be an insidious comorbidity in LAS and CAI. Overlooked physical impairment in the midfoot or forefoot may result in persistent limitation in function, disability, and/or impaired quality of life. It is clinically imperative for healthcare providers to assess and treat the ankle-foot complex as a whole, to include the midfoot and forefoot, even when symptoms are not manifest.

Examination and treatment of the midfoot and forefoot should complement the thorough examination and treatment of the proximal and distal tibiofibular, talocrural, and subtalar articulations typically performed following injury. Based on the prevalence, cost, morbidity and progression to CAI type symptoms develop at the same rate in isolated midfoot injury as it does in LAS,16 the examination and treatment of the midfoot and forefoot may furnish additional pertinent information to the treating provider and allow for a more comprehensive plan of care. The midfoot may have a larger contribution to normal neurophysiologic and mechanical function than previously thought. Further research focused on investigating the role of multisegmented foot kinematics in individuals with LAS and CAI, development and validation of clinical tests of the midfoot and forefoot is suggested.

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