Clinical Assessment of Manipulation and Mobilization of the Lumbar Spine A Critical Review of the Literature RICHARD P. Dl FABIO The widespread use of manual therapy techniques suggests some degree of success in their application. In this article, I review the applied clinical research on the effectiveness of using manipulation or mobilization of the lumbar spine. The literature reviewed indicates highly equivocal results when the goal of therapy was to decrease pain and increase motion. Because of a high incidence of spontaneous recovery from low back syndromes, performance measures may appear to improve significantly when proper controls are not used. Evaluation of the therapeutic effects of manual therapy is complicated by potentially confounding variables when used with other physical therapy procedures. I discuss the need for further, well-designed studies. Key Words: Backache; Lumbar region; Manipulation, orthopedic; Physical therapy; Spine.
Nonsurgical treatment of the low back is widely used, but its effectiveness for reducing pain and improving limited motion is poorly documented.1-4 Traditional physical therapy for low back syndromes has included the use of modalities, exercise, patient education, and posturing.5,6 Manual therapy (manipulation or mobilization or both) has been advocated as a primary treatment for the patient suffering from back dysfunction7-11; the common use of these techniques suggests some degree of success in their application. Although certain practical restraints may limit strict control of the experimental design, the results obtained from poorly controlled investigations of manual therapy must be questioned. The clinical efficacy of manipulation and mobilization has yet to be established reliably under controlled conditions. A critical review of manual therapy is necessary to provide a perspective for the management of low back dysfunction. Throughout this article, the term "manual therapy" applies broadly to lumbar manipulation and mobilization techniques, as presented elsewhere,7-11 unless otherwise stated.
Dr. Di Fabio is Director of Physical Therapy, University of Wisconsin Hospital and Clinics, 600 Highland Ave, Madison, WI 53792 (USA). This article was submitted January 10,1985; was with the author for revision two weeks; and was accepted July 11, 1985.
Volume 66 / Number 1, January 1986
REVIEW OF LITERATURE Noncontrolled Investigations of Manipulation and Mobilization A large percentage of patients with low back pain are likely to recover spontaneously regardless of the type of treatment received.2,12 Studies without the proper controls have no mechanism for ensuring that the observed effects resulted from manual therapy, patienttherapist interaction, or a natural recovery process. Mensor performed rotary manipulations on 205 patients who had backache and reported that nearly half (96) obtained excellent or good results from the treatment.13 In a retrospective study of 2,920 patients attending 43 osteopathic practices in Great Britain, over 80% of the patients indicated a satisfactory result from some manual therapy procedure.14 The majority of individuals participating in other noncontrolled studies also have shown considerable improvement in signs and symptoms after manipulation.15"18 Price reported that 59% of a sample of 73 patients indicated that their low back pain remitted after a single week of manipulative treatment.19 The time course of the reduction in symptoms led Price to speculate that the incidence of spontaneous relief of pain was low. Determination of whether the improvement in any measured outcome resulted from therapy or spontaneous recovery was impossible because no control or comparison group was in place. Most noncontrolled studies were difficult to compare because the character-
istics of the patient sample, the nature of the treatment, and the method of assessment were highly variable. Mensor excluded patients with spinal osteoporosis, degenerative disk disease, spondylolisthesis, and motor weakness but allowed patients with weak toe extensor muscles to receive manipulation.13 Burton did not identify specific diagnostic categories,14 and Price sampled subjects with "pain of spinal origin."19 Manual therapy procedures differed across studies and were defined operationally as traction and rotary manipulation under Sodium Pentothal,速*13 deep soft tissue massage, graded mobilization, high velocity thrust, manual and mechanical traction,14 and rotary manipulation with analgesics.19 These broad definitions increase the difficulty in comparing results between studies. Clinically objective measurements of lumbar dysfunction and assessment tools with established reliability are difficult to find. The various pain rating scales represent a subjective assessment tool. A report of pain by the patient before and after manual therapy was often used as a primary index of therapeutic success or failure.14-19 Range-ofmotion measurements, for example, rarely were included in the assessment. Controlled Studies of Manipulation and Mobilization The interpreted efficacy of lumbar manual therapy often hinges on experi* Abbott Pharmaceuticals, Inc, North Chicago, IL 60064.
TABLE Summary Characteristics of Patient Samples and Types of Manual Therapy Described in Selected Controlled Studies of Manipulation and Mobilization for Low Back Dysfunction (LBD) Study Fisk20 Evans et al21 Nwuga22
Doran and Newell23
Godfrey et al26
Sims-Williams et al28 Jay son et al12 Glover et al29
Bergquist-Ullman and Larsson5
Sample Characteristics Unilateral LBD LBD for three weeks (Exclusions: root compression) Disk protrusion confirmed by EMG and myelogram (Additional criteria: no prior treatment, onset within two weeks, unilateral reflex and sensory signs) LBD (Exclusions: psychological disturbance, pregnancy, scoliosis, root pain, straight leg raising less than 30 degrees, sensory loss, weakness, atrophy, abnormal reflexes, hip osteoarthritis, previous manipulation, corset, spondylolisthesis, bowel or bladder disorder) LBD (Criteria: noninflammatory origin and limited spinal motion. Exclusions: ageâ€”below 18 years, over 68 years; gross radiologic deformity, restriction of motion in two or more noncontinuous planes) LBD (Exclusions: spondylitis, Paget's disease, bladder or bowel disorder, previous spinal surgery, pregnancy, psychological disturbance) LBD (Exclusions: bilateral pain, abnor-
mal radiological and neurological signs) Acute LBD (Criteria: no radiation, duration of pain less than three months, pain-free one year before current onset)
mental design and protocol. The presence of control groups, random assignments to control and treatment groups, and blind assessment of the outcome of intervention are critical factors to be considered for a valid clinical trial. Interpretations of the efficacy of spinal mobilization and manipulation are limited when the effects of manual therapy are confounded by other forms of physical therapy treatment. Fisk administered rotary manipulation as the sole treatment for 10 carefully selected patients who had similar symptoms.20 The resistance to bilateral passive hamstring stretch during straight leg raising was measured before and after manual therapy in the patient sample and in a sample of 10 healthy volunteers. The patients with back pain demonstrated an asymmetry in hamstring tension that was reduced significantly after manipulation. Evans et al used a controlled crossover trial in which two groups of patients 52
Manual Therapy Rotary thrust Rotary thrust (bilateral) Rotary oscillations
"At discretion of manipulator"
(lower spine and sacrum) Mobilization
with back pain received a course of rotary manipulation with analgesics or analgesics alone.21 After 42 days, both groups had received both types of intervention but in a different sequence. An increase in forward bending during the trials of manual therapy was contrasted with a decrease in this motion during trials with analgesics alone. Pain decreased only in the group manipulated first. Nwuga used rotary oscillations in combination with lifting and posture instructions.22 The control group received short wave diathermy, pelvic tilt exercise, and lifting instructions. The manual therapy group showed an increase in active spinal motion (osteokinematic) and significant improvement in SLR. As in the Evans et al21 study, all measurements were made by a physician or therapist who had no knowledge of patient group assignment. Controlled studies producing positive results from joint manipulation and mo-
bilization have not been widely reproduced. Bergquist-Ullman and Larsson compared spinal mobilization, a back school program, and a placebo.5 At 10 days, three weeks, and six weeks after treatment, a similar decrease in pain was observed in 182 patients representing all three groups. When days of sick leave from work because of recurrence of low back pain were compared, no significant differences were found between groups. In a multicenter study, Doran and Newell reported no difference in pain and spinal motion of 456 patients randomly assigned to one of four groupsâ€”manipulation, modality and exercise, corset, and oral analgesics.23 This study received considerable criticism for using poor patient selection criteria and for applying manipulative techniques that were inconsistent.24,25 Other blind controlled studies have improved on patient selection criteria and have standardized manual therapy protocol but still have produced negative results. Godfrey et al used four experimental groups in a single, blind randomized trial of rotational manipulation.26 Group 1 received soft tissue massage and a rotational thrust of the type described by Maigne.27 Group 2 received manipulation and electrostimulation of the paraspinal muscles with the subjects in the prone position. Massage only (Group 3) and electrostimulation only (Group 4) completed the array of randomization. Subjective assessments of pain and activities of daily living were combined with objective assessments of passive and active spinal motion. No significant differences were seen in the outcomes among any group. One difficulty inherent in the design of many clinical studies was the potential influence of a placebo on the outcome measures. This issue was briefly addressed by Godfrey et al who stated that, "The credibility and efficacy of various placebo treatments have never been investigated, and without an appropriate placebo treatment, bias [from the patient's perspective with regard to their treatment] cannot be identified and minimized."26(p304) Jayson et al12 and Sims-Williams et 28 al applied Maitland's7 technique and found that pain reduction and spinal motion improved for both manual therapy and placebo groups. Patients who began the study as outpatients and who had a shorter duration of symptoms, however, reported more of an improvePHYSICAL THERAPY
ment from therapy than did the controls one month after treatment. A one-year follow-up showed that groups receiving manual therapy had no better improvement than controls. In fact, the control groups were significantly better on pain measures. Jayson et al concluded that, "In patients likely to improve anyway, mobilization and manipulation may hasten improvements, but do not affect the long term prognosis. "12(p409) The immediate advantage of manipulation and mobilization has been reported by others. Glover et al measured patients' complaints of pain 15 minutes after rotational manipulation.29 The manipulated group reported significantly greater relief compared with a matched group receiving simulated short wave diathermy. The groups had no difference between them three and seven days postintervention. Findings that suggest that mobilization is no more effective than placebo deserve further scrutiny. Zybergold and Piper assigned 28 patients to three groups.30 The first group received moist heat and flexion exercises; the second group received a home program in back care; and the third group received heat, gentle mobilization, and manual traction. Because the same therapist administered all treatments, the possibility of experimenter bias cannot be overlooked. If, however, the bias was in favor of any given form of treatment, it did not surface in the results. No significant differences were found when pain indexes, motion, and functional ability were compared across the three groups. Distinct benefits resulting from manual therapy have been alleged in studies that did not assign patients randomly to various experimental groups, made performance evaluations with full knowledge of the intent of treatment, or used contaminated controls.31,32 Flaws such as these in the experimental design make the results tenuous. In brief, when clinical trials of spinal manipulation and mobilization are controlled properly, a definite, but small, short-term effect can be seen. Longer term effects are more equivocal, and the comparison of many studies is complicated by the potential combination of manual therapy with other physical therapy procedures. Different methods of patient selection, manual therapy techniques, and outcome assessment tools further complicate cross-study comparisons. I summarized selected Volume 66 / Number 1, January 1986
controlled studies in the Table to illustrate that exclusions from patient samples and the descriptions of manual therapy vary considerably. The individual studies should be read to obtain the specific details in context. DISCUSSION Progress in treating low back pain has been limited because of a lack of scientifically tested protocols and highly speculative theories on the mechanism(s) of therapeutic action.2-4,33 Haldeman evaluated the scientific basis for manipulative therapy and proposed that therapy must be demonstrated to have consistent results under controlled conditions and to have a specified effect on the musculoskeletal or neuromuscular system.3 Moritz suggested that the variables used to quantify the outcome of manual therapy must be reviewed and specified in more detail.4 For instance, measuring the angle of hip flexion during SLR provides limited information because of the potential for false positive tests. A high interobserver reliability has been found for measurements of mobility in multiple lumbar segments,34 but correlations of segmental mobility with clinical dysfunction are not impressive.35 Additionally, measures of improvement in functional capacity are difficult to interpret because emotional and physical factors contribute to function. Controlled studies that measured spinal range of motion focused primarily on active physiological movement (ie, the extent of forward bending) 12,21,22,26,28,30
study reported an attempt to measure both active and passive physiological motions.26 In all of the studies reviewed, an evaluation of spinal component motions (eg, glide, spin) was not apparent. Pain indexes varied widely in the controlled studies, and reports of reliability were scant. The pain scales I reviewed included four levels,21fivelevels,26,30 and six levels.12,23,28 One study recorded the patient's "percent relief of pain" and the duration of relief after manual therapy.29 Others included a count of the number of analgesic tablets as an index of improvement,21 and some authors totally omitted evaluation of pain.20,22 Valid research findings are complicated by difficulties in diagnosing the precise source of symptoms.1,36 Based on estimates from Dillane et al, over 80% of all acute complaints of low back
pain have an unknown etiology.37 In addition, the interplay of variables such as the skill level of clinicians performing manual therapy, selection of patients with different conditions, and the use of manual therapy with other therapeutic modalities may all contribute to equivocal results. Continuation of soundly designed investigative work is a necessary, yet difficult, task facing practitioners. CONCLUSIONS This review has produced more questions than answers regarding the efficacy of manual therapy. For example, what is the mechanism of action of manual therapy? Is mobilization (vs manipulation) more effective with certain diagnostic categories? How should the knowledge of spontaneous recovery of many patients with back pain alter an approach to treatment? When should treatment be started, how long should it last, and how long are treatment effects sustained? The answers to these questions will provide physical therapists with the tools needed to use effective clinical interventions and to scrutinize the continuing development of manual therapy techniques.
REFERENCES 1. Progress in back pain? Lancet 1:977-979, 1981 2. Nachemson A: A critical look at the treatment for low back pain. In Goldstein M (ed): The Research Status of Spinal Manipulative Therapy. Bethesda, MD, NINCDS Monograph No. 15, Dept of Health, Education, and Welfare publication No. (NIH) 76-988, 1975, pp 287293 3. Haldeman S: The clinical basis for discussion of mechanisms of manipulative therapy. In Korr IM (ed): The Neurobiologic Mechanisms in Manipulative Therapy. New York, NY, Plenum Publishing Corp, 1978, pp 53-75 4. Moritz U: Evaluation of manipulation and other manual therapy. Scand J Rehabil Med 11:173179,1979 5. Bergquist-Ullman M, Larsson U: Acute low back pain in industry. Acta Orthop Scand [Suppl] 170:1-110,1977 6. McKenzie RA: The Lumbar Spine: Mechanical Diagnosis and Therapy. Wellington, New Zealand, Spinal Publications, 1981 7. Maitland GD: Vertebral Manipulation. London, England, Butterworth, 1977 8. Grieve GP: Mobilization of the Spine, ed 3. Edinburgh, Scotland, Churchill Livingstone, 1979 9. Kaltenborn F: Mobilization of the Spinal Column. Wellington, New Zealand, University Press, 1970 10. Paris SV: Mobilization of the spine. Phys Ther 59:988-995,1979 11. Cyriax JH: Textbook of Orthopaedic Medicine, ed 6. Baltimore, MD, Williams & Wilkins, 1976, voM
12. Jayson MIV, Sims-Williams H, Young S, et al: Mobilization and manipulation for low back pain. Spine 6:409-416,1981 13. Mensor MC: Non-operative treatment including manipulation for lumbar intervertebral disc syndrome. J Bone Joint Surg [Am]37:925-936, 1955 14. Burton KA: Back pain in osteopathic practice. Rheumatology and Rehabilitation 20:239-246, 1981 15. Fisk JW: Manipulation in general practice. NZ Med J 74:172-175, 1971 16. Henderson RS: The treatment of lumbar intervertebral disc protrusion. Br Med J 2:597-598, 1952 17. Hutton SR: Combination of traction and manipulation for lumbar disc syndrome. Med J Aust 54:1176,1967 18. Warr AC, Wilkinson JA, Burn JMB, et al: Chronic lumbosciatic syndrome treated by epidural injection and manipulation. Practitioner 209:53-59, 1972 19. Price ODI: Manipulative methods for treating locomotor pain in general practice. J R Coll Gen Pract 21:214-220,1971 20. Fisk JW: A controlled trial of manipulation in a selected group of patients with low back pain favoring one side. NZ Med J 90:288-291,1979 21. Evans DP, Burke MS, Lloyd KN, et al: Lumbar spinal manipulation on trial: Part I—Clinical assessment. Rheumatology and Rehabilitation 17:46-53,1978 22. Nwuga VCB: Relative therapeutic efficacy of vertebral manipulation and conventional treatment in back pain management. Am J Phys Med 61:273-278, 1982 23. Doran DML, Newell DJ: Manipulation in the treatment of low back pain: A multicentre study. Br Med J 26:161-164,1975 24. Cyriax JH: Manipulation in the treatment of low back pain. Br Med J 2:334,1975 25. Ebbetts J: Manipulation in the treatment of low back pain. Br Med J 2:393,1975 26. Godfrey CM, Morgan PP, Schatzker J: A randomized trial of manipulation for low-back pain in a medical setting. Spine 9:301 -304, 1984 27. Maigne R: Douleurs d'origine Vertebraie et Traitements par Manipulations. Paris, France, Expansion, 1968 (French) 28. Sims-Williams H, Jayson MIV, Young SMS, et al: Controlled trial of mobilization and manipulation for low back pain: Hospital patients. Br Med J 2:1318-1320,1979 29. Glover JR, Morris JG, Khosla T: Back pain: A randomized clinical trial of rotational manipulation of the trunk. Br J Ind Med 31:59-64,1974 30. Zybergold RS, Piper MC: Lumbar disc disease: Comparative analysis of physical therapy treatments. Arch Phys Med Rehabil 62:176-179, 1981 31. Coyer AB, Curwen IHM: Low back pain treated by manipulation. Br Med J 1:705-707, 1955 32. Chrisman OD, Mittnacht A, Snook GA: A study of the results following rotary manipulation in the lumbar intervertebral-disc syndrome. J Bone Joint Surg [Am]46:517-524,1964 33. Dixon ASJ: Progress and problems in back pain research. Rheumatology and Rehabilitation 12:165-175, 1973 34. Fitzgerald GK, Wynveen KJ, Rheault W, et al: Objective assessment with establishment of normal values for lumbar spinal range of motion. Phys Ther 63:1776-1781, 1983 35. Roberts GM, Roberts EE, Lloyd KN, et al: Lumbar spinal manipulation on trial: Part II— Radiological assessment. Rheumatology and Rehabilitation 17:54-59, 1978 36. National Institute of Neurological and Communicative Disorders and Stroke Monograph No. 15: The Research Status of Manipulative Therapy. Bethesda, MD, Dept of Health, Education, and Welfare publication No. (NIH) 76-998, 1975 37. Dillane JB, Fry J, Kalton G: Acute back syndrome—A study from general practice. Br Med J 2:82-84,1966