Contributors
Nikolai Bogduk., MD, DSc
Director,NewcastleBone & Joint Institute,UniversityofNewcastle, RoyalNewcastleHospital,Newcastle, NewSouthWales,Australia
David S. Butler, BPhty, MAppSc
AdjunctSeniorLecturer,Schoolof Physiotherapy,UniversityofSouth Australia;Private Practitioner, Goodwood,Adelaide,SouthAustralia, Australia
Judi Carr, AVA, Grad Dip FE MurrayMallee Community Health Service, Murray Bridge,South Australia,Australia
Nicole Christensen, MAppSc, PT, OCS, FAAOMPT
Orthopaedic Curriculum Coordinator, Department ofPhysicalTherapy, Mount St.Mary'sCollege,LosAngeles, California
Brian C. Edwards, OAM,BSc(Anat), BAppSci (physio), Grad Dip, Manip Th, FACP, Hon DSc (Curtin) Specialist,ManipulativePhysiotherapist, Mount Medical Centre, Perth, Western Australia,Australia
Ruth Grant, BPT, MAppSc, Grad Dip Adv Man Ther ProfessorofPhysiotherapy,ProVice ChancellorandVice President, Division of Health Sciences,UniversityofSouth Australia,Adelaide,SouthAustralia, Australia
Jan Lucas Hoving, PT, PhD
Department ofClinicalEpidemiology, Cabrini Hospital, Monash University Department of Epidemiology and PreventiveMedicine, Cabrini Medical Centre, Malvern,Victoria,Australia
Vladimir Janda, MD, DSc
Professor Emeritus, Department of Rehabilitation Medicine, Postgraduate Medical Institute, CharlesUniversity Hospital,Prague,CzechRepublic
Mark A. Jones, BS, MAppSc
Senior Lecturer and Coordinator, Postgraduate Programs inManipulative Physiotherapy,SchoolofPhysiotherapy, Divisionof Health Sciences, University ofSouthAustralia,Adelaide,South Australia,Australia
Gwendolen A. Jull, PhD, MPhty, Grad Dip Manip Ther, FACP
Associate Professor andHead, Department of Physiotherapy, The Universityof Queensland, Brisbane, Queensland,Australia
Bart w Koes, PhD
Professorof General Practice, Department of General Practice, ErasmusUniversity, Rotterdam, The Netherlands
Diane Lee, BSR, MCPA, FCAMT Private Practitioner, Delta Orthopaedic Physiotherapy Clinic,Delta,British Columbia,Canada
Mary E. Magarey, PhD
SeniorLecturer,Schoolof Physiotherapy,Divisionof Health Sciences, University of South Australia, Adelaide, South Australia,Australia
Stephen May,MA, MCSP, Dip MTD,MSc
Superintendent Physiotherapist, Physiotherapy Department, Walton Hospital, Chesterfield, Derbyshire, United Kingdom
Mary Kate McDonnell, MHS, PT, OCS
Instructor, Program inPhysical Therapy, Washington University, Schoolof Medicine, St.Louis,Missouri
Robin A. McKenzie, CNZM, OBE, FCSP (Hon), FNZSP (Hon), Dip MDT
President, McKenzie Institute International, Waikanae, New Zealand
Barbara McPhee, Dip Phty, MPH Professional Ergonomist and Physiotherapist, The OH&S Services Network, Ryde, New South Wales, Australia
Shirley Sahrmann, PhD, PT, FAPTA Professor,Physical Therapy, Cell Biology,andPhysiology;Associate Professor, Department of Neurology; Director, Program in Movement Science, Washington University,School of Medicine,St.Louis,Missouri
Helen Slater, MAppSc, BAppSc Lecturer and Coordinator, SportsClinic 652; Master ofSportsPhysiotherapy, SchoolofPhysiotherapy, Curtin University ofTechnology, Perth, Western Australia,Australia
James R. Taylor, MD, PhD, FAFRM (Sci)
Adjunct Professor,School of Health Sciences, Curtin University of Technology;VisitingProfessor, Australian Neuromuscular Research Institute, Queen Elizabeth II Medical Centre, Perth, Western Australia, Australia
Patricia H. Trott, MSc, Grad Dip Adv Man Ther, FACP
AdjunctAssociateProfessor,School of Physiotherapy, University of South Australia,Adelaide, South Australia, Australia
Lance Twomey, AM, PhD, BSc (Hon)
President andVice Chancellor, Curtin University of Technology, Perth, Western Australia,Australia
David R. Worth, PhD, MAppSc, BAppSc (physio)
Senior Consultant, Rankin Occupational Safetyand Health, Mile End, South Australia,Australia
Anthony Wright, BSc (Hons) Phty, MPhty St (Manip Ther), PhD Professor and Head, School of Physiotherapy, Curtin University of Technology, Perth, Western Australia, Australia
Preface
Physicaltherapistsinvolvedinthe management of patients with symptoms arising fromthecervicalandthoracicspinefacesimilarchallengestothosein1994whenthe secondeditionofthisbookwaspublished,andindeed,tothosefacedin1988when thebookwasfirstpublished. Headache andneckpainaffecttwo thirds ofthe populationandremainasubiquitoustodayastheydidthen.
This third editionof Physical Therapy ofthe Cervical and Thoracic Spine, however, demonstrates theprogressioninknowledgeand understanding that hastakenplace sincethepublicationofthefirst edition-increased knowledgeand understanding of the structure andfunction of thecervicalspineinparticular, of muscle recruitment andtherole of musclesinsegmentalstabilization,ofthepainsciencesand their underpinning of patient assessmentand management, of clinical management approachesand their basesinclinicalresearch, contemporary science,andclinicalhypothesis. Our knowledgeoftheeffectsandefficacyofmanual therapy inthe treatment ofthecervicalspinehasincreasedsignificantlyovertheseyears. In 1988,few randomized controlled trialsaddressedtheefficacy of treatment approachesforneckpain. There areconsiderablymorepublishedtoday.Twonew chapters inthis third edition, Chapter 12byProfessor Anthony Wright and Chapter 20byDr. Jan Hoving and ProfessorBartKoes,illustratethis greater knowledge.
Sackettet al* defined evidence-based practice as "the integration of bestresearch evidencewithclinicalexpertiseand patient values."Sackettetalemphasize that "whenthese three elementsare integrated, cliniciansand patients formadiagnostic and therapeutic alliancewhichoptimisesclinicaloutcomesandquality of life." This isatimely reminder fromthe "Father ofEvidence-Based Medicine" that treatment basedonbestresearchevidence alone, albeit important, is not evidence-basedpractice asdefined. This third edition providesbestresearchevidenceand, concomitant with that, contributions from eminent cliniciansbasedon that researchevidence,oncontemporary biomedicalknowledgeand pathophysiological considerations, oronasystematiccriticallyevaluativeapproach.
The bookis presented inthree interrelated partsasbefore. The first part (Chapters1to5)provides up-to-date knowledgeoffunctionalandappliedanatomy,biomechanics,and innervation andpain patterns ofthecervicalandthoracicspine,witha new chapter onthebiomechanicsofthethorax (Chapter 3).
The second part ofthebook,whichisonexaminationandassessment (Chapters 6to11),providesasolidand contemporary baseforthe practicing clinicianandemphasizes inter alia,aclinicalreasoning approach to orthopedic manualtherapy;a movement impairment approachintheexaminationofthecervicaland thoracic spine, rather thanonerelatedtospecific structural diagnosis;clearevolutionin our under-
*Sackett DL, Straus SE, Richardson WSetal: Evidence-based medicine, ed2, Edinburgh, 2000, Churchill Livingstone.
standing of neurodynamics;andanupdateandreappraisal of premanipulative testing of thecervicalspine.
The third part,onclinical management and evidence-based practice (Chapters 12 to21),hasbeenexpandedandincludessix completely new chapters. The chapters are written by eminent cliniciansand researchers andwill undoubtedly provevaluableto physicaltherapistsin their greater understanding and more effective management of patientswho present with upper quarter dysfunction.
The final chapter (Chapter 21)reflectsmore broadly onthe changing nature of professionalpractice,theknowledgeexplosion,andthechallenges of knowledgemanagement. This chapter considersalsothe centrality of the patient andofclinicalexpertise,aswellasresearchevidence,insuccessful evidence-based practice.
RuthGrant
Functional and Applied Anatomy ofthe Cervical Spine
James R. Taylor and Lance 'rwomev
CHAPTER
OVERVIEW
The human spine,asawhole,combinesthefollowing three important functions:
1.Itformsastable osteoligamentous axisfortheneckandtorsoandforthe support ofthehead,torso,andlimbs.
2. It providesavarietyandrange of movements that areessentialfor human tasksrelated to positioning ofthe upper limbsandhands,varyingthe direction ofvision and contributing to locomotion.
3. It formsa protective conduit forthespinalcordanditsnerves, conducting them ascloselyaspossible to thepointsof distribution ofthespinalnervestotheparts theyinnervate.
The cervicaland thoracolumbar regions of thespineshow significant contrast in their functionsof weightbearing and movement. In the thoracolumbar spine,stabilityin load bearing isthe primary requirement, whereasthecervicalspineisspecializedfor mobility. The cervicalspine not onlyholdstheheadup, but italso directs thegaze through arangeof180degreesinthe horizontal planeandarangeof about 120degreesinthevertical plane.' The severe handicap posedbyneckstiffness(e.g.,apersonwithankylosingspondylitisdrivingacar) illustrates the importance ofrapid,wide rangemobilityintheneck.
This functional contrast between thecervicalspineandtherestofthespineisreflectedbymanydifferencesintheshape,size,and structure ofits vertebrae anditsintervertebral joints. The firsttwocervical vertebrae areunique,and their synovial joints contribute nearlyone third oftheflexion-extensionand more than half ofthe axial rotation ofthecervicalspine. The remainder ofthecervicalspine,withitssix motion segments (fromC2-3to C7-Tl), ismuch more slender and mobile thanthe six motion segments ofthe lumbar spine.i These cervicaljointscollectivelyprovidea sagittalrangeofupto90degrees compared to about 60degreesinthe lumbar spine. The lowercervicaljointsallowawiderangeofaxial rotation, a movement that isrestrictedinthe lumbar spine.l-"
The structural features that determine these contrasts infunction between cervicaland lumbar regionsarethe greater slenderness of the cervicalspine,markeddif-
ferencesinfacetshapeand orientation, andthepresenceof prominent uncinate processesoncervicalvertebrae. The uncinateprocesses project upwardfromthelateral marginsofeachcervicalvertebralbody; there areno uncinate processesin lumbar vertebrae.i'" Althoughthecervicalspineisthemost slender part ofthespine,ithas thewidestspinalcanal,sinceitcarriesthethickest part ofthespinalcord.
This slendercolumnsupportsthehead,whichweighs about 4kg.s The support ofaheavyheadonaslender,highlymobilestalkmakestheneck vulnerable toinjury. Inour postmortem study of spinalinjuriesin385victims of roadtrauma,halfofall thespinalinjuriesweretothecervicalspine." Control ofthe motor andsensoryfunctionsofthetorsoandallfourlimbsis transmitted through thecervicalspinalcord,so injurytothecervicalcordcausesquadriplegia. The bloodvessels that supplythe brainstem,cerebellum,andoccipitallobes of the cerebrum alsopassup through the cervicaltransverseprocessesandbehindthelateralmassesofC1. Injury tothe vertebralarteriesisararecomplicationof manipulation ofthecervicalspine.!"
These general considerations makeit abundantly clear that asoundandpractical knowledgeofthefunctionalandappliedanatomyofthecervicalspineisessentialfor anyhealthprofessionalwhowouldexamine it and understand or treat cervicalpainor dysfunction. This accountbeginswithareviewofspinal development andgrowth, then providesdescriptionsofadultanatomyandmovements, common featuresofaginginthecervicalspine,andthe anatomy ofinjuriesandpainofcervicalspinalorigin.
RESUME OF DEVELOPMENT
Inthethirdweekofembryoniclife,the longitudinal axisoftheembryoisformedby thegrowthofthe notochord betweenthe ectoderm andthe endoderm. The notochord isthe precursor ofthevertebralcolumn,andtheneuraltubeisformedparallel anddorsaltothe notochord. Paraxial mesoderm developsoneachsideofthe notochordandneuraltube. 11 The original notochord hasan important influenceonthe ectoderm that isdorsaltoit.Itinduces thickening oftheadjacentdorsal ectoderm to formtheneuralplate,whichfoldstoformtheneuraltube.Atthesametimethe paraxialmesodermoneachsideofthe notochord andneuraltubeis segmenting into regularblocksof mesoderm called somites. The notochord andneuraltube together inducethemesodermalcellsofthesomitestoforma continuous cylindrical mesodermal condensation around them calledthe primitive vertebral column (Figure1-1). The medialpartsofthesomites(sclerotomes)aretherawmaterialfromwhichtheoriginal vertebralcolumnismade. The dorsalaortadescends anterior totheoriginal vertebral column,anditsregular intersegmental branchessupplythismesodermal vertebral column.Vertebralcolumn development isusuallydescribedinthefollowing three stages. 12 ,13
MESODERMAL STAGE
The mesodermalcolumnisformedaroundthe notochord bytissuefromthe ventromedial,sclerotomic portions ofthesomites. Although formedfromthesomites,this mesodermalcolumnis continuous and unsegmented. It resegments into alternate light-and-dark bandsallthewayalongits length (Figures1-1and1-2). Neural processesgrow around theneuraltubefromeachlightband. The aortasends intersegmentalbranches around themiddleofeachlightband. The light bandshavea better bloodsupplyandgrowin height morerapidly than theadjacentdarkbands (Figure 1_2).14
Neuraltube
Neural process oflightband
Figure 1-1
Diagramofa7-rnrn humanembryowithexternalfeaturesremovedfromthecentralpartto showmidlinestructures,includingthe notochord enclosedintheprimitivevertebral column;thelightbands(primitivevertebrae)withtheirneuralprocessespartlyenclosingthe neuraltube;andthedorsalaortawhoseintersegmentalbranchessupplythelightbands.
IFrom Taylor JR, Twomey LT. InGrieve GP, editor: Modern manual therapy ofthe vertebral column, Edinburgh, 1986, Churchill Livingstone.)
Notochord
Darkband
Lightband with intersegmental vessels
Figure 1-2
Diagramofcoronalsectionofa7-mmembryoshowingthe alternating lightbands(primitivevertebrae)anddarkbands(primitiveintervertebral discs). The intersegmentalbranches oftheaortaliewithintheperiphery of thelightbands.
(From Taylor JR, Twomey LT. InGrieve GP, editor: Modern manual therapy ofthe vertebral column, Edinburgh, 1986, Churchill Livingstone.)
CARTIlAGINOUS STAGE
Eachlightband,withitsneuralprocesses, differentiates intoacartilaginousmodel of avertebraat about 2 months' gestation. The differentiation andrapidgrowthofthe lightbandsintofetalcartilagemodelsof vertebral bodiesisaccompaniedby notochordal segmentation. The cylindrical notochord swellswithineachdarkbandor primitive intervertebral discand constricts anddisappearsfromeach cartilaginous vertebra.Each notochordal segment willformanucleuspulposusatthe center ofa disc.Atthe periphery oftheprimitive intervertebral disc,fibroblastslaydowncollagenfibersinoutwardlyconvexlamellae. The cartilaginousstageof vertebral development isa short one,andbloodvesselsgrowintothecartilaginousvertebra, heralding theappearanceoftheprimarycentersofossification.
OSSEOUS STAGE
Three primarycentersofossificationareformedineachvertebra.Bilateralcentersfor thevertebralarchappearfirst, then one center appearsforeachvertebralbody. The earliestvertebralarchcentersareinthe cervicothoracic region;hencecervicalarches ossifyrelativelyearly,andsacrococcygeal centers appearlast. The single anterior ossification center formsthe centrum ofeachvertebralbody. The firstcentraappearin the thoracolumbar region,andthecervicalcentraappearrelativelylate.
Ossificationextendsfromthe three primary centers through thecartilagemodel ofeachvertebra,replacingcartilagewithbone,exceptfor three cartilagegrowthplates. Bilateral neurocentral growthplatesandasingle,midlinegrowthplatebetweenthe laminaepersist in the ring around thespinalcanaltoensure continued growth in girth ofthecanaltoaccommodateearlyrapidgrowthofthespinalcord. When the spinalcanalreachesthe required girth,thethreegrowthplates around itfuse. The halvesofthevertebralarchfuseatabout1yearafterbirth. The bilateral neurocentral growthplatesbetweenthearchandthe centrum, oneachside,fuseat 3 years of ageincervicalvertebrae. The cervical neurocentral growthplatesarewithinthevertebralbody,sothelateral quarters ofeachcervical vertebra areossifiedfromthevertebralarchesandtheuncinateprocesseswilllatergrowupwardfromtheselateral parts.
Growth platesandcartilageplatesalsocoverthe upper andlowersurfacesofthe vertebralbody,nexttothediscs,toensuregrowthinvertebral height. Eachcartilage plateremainsunossified throughout itslife,exceptatits circumference, wherearing apophysisappears. This bonyringapophysisappearsbetween9and12yearsofage andfuseswiththevertebralbodybetween16and18yearsofage,atthe completion ofvertebralgrowth,2yearsearlierinfemales than inmales.
GROWTH IN LENGTH OF THE VERTEBRAL COLUMN
Growth ismostrapidbeforebirth,andtheratedecreasesprogressivelyininfancyand childhood, withafinalgrowth spurt atadolescence. The spine contributes 60%ofsittingheight.Ameasureofspinelength, sitting height increasesby5cminthesecond year oflife, by2.5cmperannumfrom4to7yearsofage,thenby1.5em per annum from9to10yearsofage. During theadolescent growth spurt,thespineincreasesto agrowthvelocityof4cmperannum(peakingat12years of ageingirlsandat14years ofageinboys).Sitting height reaches99%ofitsmaximum length by15yearsofage ingirlsand17yearsofageinboys. 15
NOTOCHORDAL,NEURAL,VASCULAR,AND MECHANICAL INFLUENCES ON DEVELOPMENT
The notochord andneuraltubeinduce formation of the mesodermal vertebral columnaroundthemfromthemedialparts of thesomites.Regular segmentation of the mesodermalcolumnisinfluencedbythe regular arrangement of intersegmental arterieswithinit. The notochord makesasmaller contribution totheoriginalnucleuspulposusincervicaldiscsthaninlumbardiscs,but notochordal tissue atrophies anddisappears during childhoodinbothregions. The smaller notochordal contribution to thecervicalnucleusandthe greater contribution tothecervicalnucleusfromsurrounding fibroblasticcellsmeans that fromanearlystage there ismorecollageninthe cervicalnucleusthanin other regions.
The persistenceoflive notochord cellsin vertebrae mayleadtothe formation of chordomasinadults. These rare malignant tumorsareusuallyseeninhigh retropharyngealorlowsacrococcygealsituations. Congenital fusion of vertebrae, "butterfly vertebra," or hemivertebra, mayresultfrom abnormal development of the notochord orthesegmentalbloodvessels. Congenital fusion of vertebrae isquite common inthe cervicalspine.
Growth of thespinalcordinfluences growth ofthe vertebral archesandcanal, justasbrain growth influencesskull-vaultgrowth. An enlarged spinalcordresults inanenlargedcanal.Spinabifidaisa developmental anomaly that variesfroma simplecleftinthe vertebral arch (spina bifida occulta), whichis common and innocuous,tocomplete splitting oftheskin, vertebral arch,and underlying neural tubewithassociatedneurologicaldeficits. In meningomyelocele, abnormal development oftheneuraltubeistheprimaryevent,andtheskeletaldefectsaresecondary. Itoccursmostofteninthelumbosacralspine,butitalsooccursinthecervical region.
The cervicalspineformsasecondary lordotic curve during thefirst6 months of postnatallife. When the infant assumes erect posture,a lumbar lordosisappears. These posturalchangesproducechangesintheshapeofthe intervertebral discsand slowchangesinthepositionofthenucleuspulposus. They also produce changesin theshape of thevertebralend-plates.
Uncinate processesgrowupwardfromthe posterolateral margins of eachcervical vertebra duringchildhood,and uncovertebral cleftsbegintoappearinthelateralparts of each intervertebral discjustbeforeadolescence. These uncovertebral cleftsorjoints areuniquetothecervicalspineandarefavored by their greater mobility andthenarrowingofthelateralparts of the interbody space.
SEGMENTATION AND VERTEBRAL ANOMALIES
NORMAL SEGMENTATION
The mesodermalcolumnisformedfromthemedialpartsofthesomites(sclerotomes),whicharesegmentedblocksofmesoderm.However,the column itselfiscontinuousand unsegmented. It resegments into itsownsequenceof alternate light-anddarkbandsso that the vertebrae developbetweenthe myotomes (segmentalblocksof musclederivedfromthemiddlepartsofthesomites);thusthemuscleswillbridge overfrom vertebra to vertebra. This alternation ofmuscleandboneisessentialtothe proper functionofthe locomotor system.
Regularlyspaced intersegmental branchesofthedorsalaortapass around each developingvertebraandprovide nutrition forrapidgrowth(Figures1-1and1-2). Vascularanomaliesmayresultinanomaliesof segmentation. 16
SEGMENTAL ANOMAUES
A hemivertebra developsifonesideofthe vertebral bodyfailstogrow.Absenceofan intersegmental vesselononesidemayresultinfailuretogrowon that side;thusonly onesidegrows,anda hemivertebra appears.Absenceofa notochordal segment may causecentratofuse,formingcongenitalfusionbetweenvertebrae. The relativelyhigh frequencyofthisoccurrenceinthecervicalspinemayrelatetothesmaller contributionmadebythe notochord tothenucleusinthecervicalregion.
CHORDOMA
Notochordal cellsproducesubstances that loosenanddigestthe inner marginsofthe surrounding envelope. This "invasive" characteristic contributes tothegrowthofthe expandingnucleusinfetusesandinfants. II Notochordal cellsdo not normally survive beyondearly childhood-except perhapsdeeplyburiedinthedevelopingsacrumorat thecraniocervicaljunctionalregion. If notochordal cellssurvive,theymaybe "released"bytraumatothe containing tissuesandbegintomultiplyagain,causingamalignant chordoma. Fortunately thisisararetumor.
BUTTERFLY VERTEBRA
The mucoidstreakpersistsuntil about 20weeks' gestation asanacellular notochordal track through thecartilagemodelsoffetal vertebrae. Ossificationofthe centrum usuallyobliteratesit.Ifthe notochordal trackpersists through the centrum afterbirth,it locallyinhibitsossificationanda butterfly vertebra maybetheresult.
NORMAL ADULT ANATOMY OF THE CERVICAL SPINE
UPPER CERVICAL SPINE
Atlas and RelatedStructures. The atlasorfirstcervical vertebra (Cl) hasaring structure aroundawidevertebralforamen that hasto accommodate boththespinal cordandthedensofC2withitsligaments.Twolateralmassesarejoinedby anterior and posterior arches(Figure1-3). Anteriorly the anterior archshowsasmall,midlinetubercleforthe upper attachment ofthe anterior longitudinal ligament; posteriorlyithasasmallmidlinefacetforthedens.Pairedtuberclesonthemedialaspect of eachlateralmassarefor attachment of thetransverse ligament thatholdsthe densinplace. The atlashasno vertebral bodybecausethe embryonic centrum of theatlasfuseswiththeaxis during development toformitsdensor odontoid process. The upper andlowerarticularfacetsonthelateralmassesof Cl formthe atlantooccipitaljointsandthelateralatlantoaxialjointsrespectively. The lateral articular facets onC1andC2do not correspond tothose of thezygapophysealjointsbelowC2asthe lateralmassesof Cl andC2areonamore anterior planethanthezygapophyseal joints. The atlashaslongtransverseprocessesbutnospinousprocess,onlyasmall posterior tubercleonthe posterior arch.!? This posterior tubercleisforthe attach-
Figure 1-3
Atlasasviewedfromabove,withthedensofC2andthetransverseligament. The diagram ofCIshowstheconcavearticularfacetsfortheoccipitalcondylesandthearticulationof theanteriorarchwiththeodontoidprocess (D) ofC2. The transverseligament,which holdsthedensinplace,isattachedtotwotuberclesonthemedialaspectsofthearticular masses. The foraminatransversariaandthelongtransverseprocessesareseenlateraltothe articular masses.
mentofthenuchal ligament andtherectuscapitis posterior minor. The tips of thetransverseprocessesmaybepalpated anteroinferior tothemastoidprocesses. The vertebralarteriespiercethemedial part ofeachtransverseprocesstowind aroundbehindeachlateralmassandgroovethe upper surfaceofthe posterior arch. The smallfirstcervicalnervespass out overthe posterior archbelowthearteries,on eachside, under coverofthe posterior atlantooccipital membrane. This membrane passesfromthe posterior archtothe posterior marginoftheforamenmagnum.Deep tothis membrane the vertebral arteriescourseupwardandmediallytotheforamen magnuminthefloorofthesuboccipitaltriangle. This triangle, between therectus capitis posterior majorandthe superior and inferior obliquemuscles,isdeeplyplaced under the overhanging occiput,coveredbythesemispinaliscapitisandthe upper fibersoftrapezius. The dorsalramusof CI supplies the three smallsuboccipital musclesandthe upper fibers of semispinalis. The deeplyplacedplexus of suboccipital veinsbehind Cl and Cl-2 haveextensive connections with vertebral veins, intracranialveins,anddeepcervicalveins. They arethinwalledandmaybebruisedinsevere whiplash injuries.l"
Athicker anterior atlantooccipital membrane attachesthe anterior arch of CI to thebaseoftheskulljustinfrontofthe anterior marginoftheforamenmagnum. This membrane iscoveredmediallybythelonguscapitisandlaterallybytherectuscapitis anterior. The smallmuscles anterior and posterior totheatlasmaybe important in cervicocapital postural control. The rectuscapitis posterior minor alsohasapartial attachment tothe posterior dura mater that keepsitfrombucklinginextensionmovementsoftheheadand neck.l"
Atlantooccipital Joint. The pairedlateralmassesoftheatlasarticulatewiththe occiputcondylesoneachsideoftheforamenmagnum. The upper articular surfaces ofC1areconcaveinthesagittalplane,andtheycloselyfit together withtheconvex occipitalcondyles(Figure1-4). The kidney-shapedC1facetsare elongated from front toback,with their anterior endscloser together than their posterior ends. Their anterior endsalso project higher thantheir posterior ends. This shapeprovidesformore extensionthanflexion in the atlantooccipital joint. 2o Atlantooccipital dislocation,or fracturedislocation,canoccurinsevereinjuriesin motor vehicleaccidents. The injuryisoftenfatalbecausethedislocationmayimpactonthe junction ofthe brainstem andspinalcord.
The upperfacetsofC1areslightlycurvedinthe coronal planewith their lateral margins higher thanthemedialmargins. Functionally the right andleftlateralatlantoaxialjointsresembletwoseparatedpartsofanellipsoid joint that allowsabout10 degreesoflateral bending oftheheadtoeachside.20 Severeaxial compression tends
Figure 1-4
This sagittalsectionfromayoungadultshowsthezygapophysealjoints,whosefacetsare orientedat45degreestothelongaxisofthespine. The biconvexatlantoaxialfacetsareincongruous;triangular,vascularsynovialfoldsoccupythe anterior and posterior partsofthe joint. The convexoccipitalcondylefitsneatlyintotheconcavefacetoftheatlas. The vertebralartery isseenintransversesectiononthe posterior archoftheatlasandinsagittal section,ascending through theforaminatransversaria of thecervicalvertebrae. The dorsal rootganglionofC2liesbehindtheatlantoaxialjointcoveredbytheinferioroblique (10) andthesuperioroblique (SO) muscles.Anteriortothearticularmasses of C3-5,thedorsal rootgangliaofC3,C4,andC5 (N) liebehindthevertebralartery.
Vascular synovial folds
Muscle
toforcethelateralmassesapart,withpossiblefractureofthe slender anterior and posterior arches(jefferson'sfracture).
Each joint isenclosedbyalaxfibrouscapsule,linedonits inner aspectbysynovialmembrane.Likethe atlantooccipital joint,this joint isoftenwellpreservedin elderlypeoplewhosecervicalzygapophysealjointshavebecome arthritic andstiff.21
Axis Vertebra(C2). The central part of theaxis vertebra isformedfromthevertebralbodyofC2 surmounted bythe toothlike densor odontoid processP The lateralmasses of C2projectoutwardfromthiscentralpart, terminating assmall transverseprocessesthatareangleddownwardandmuchsmallerthanthose of Cl. The vertebralarchofC2is stronger and thicker than that of Cl withadistinctive,thick, prominent spinousprocessintheformofaninvertedVasviewedfrom behind. The lateralmasseshave upper facetsforthelateralatlantoaxialjoints. On amore posterior plane,thelaminaehavedownwardandforward-facingfacetsfortheC2toC3zygapophysealjoints. 23
The short transverseprocessesofC2haveobliquely directed foraminatransversariaforthe vertebral arteries,whichpassupwardand outward ata 45-degree angle through C2towardthemorelaterallyplacedforaminatransversaria of Cl.
The triangular outlineonthe anterior surface of thebody of C2reflectsthenarrowingofthe upper endofthe anterior longitudinal ligament asitpassesuptoattach tothe anterior tubercleoftheatlas.24 The prominent, upwardly projecting densis coveredbehindbythetransverseligament. This isin tum coveredbythe membrana tectoria,whichistheupward continuation of the posterior longitudinal ligament. The membrana tectoriaattachesabovetothebasiocciputinsidetheforamenmagnum.
Atlantoaxial Joint. The vitally important and interesting atlantoaxial joint complexhasthree parts-two symmetricallateralpartsbetweenthelateralmasses of the atlasandaxisandacentral part formedbytheenclosure of thedens between theanterior archoftheatlasandthe strong transverseligament. These jointsprovidethe largest component ofcervicalaxial rotation, whichis required forboth voluntary and reflex turning of theheadtodirectthegazeto right orleft. The stabilityofthe joint dependsonthe integrity ofthetransverse ligament that holdsthedensinplace.25 The densactsasthe"axis"aroundwhich rotation takesplace. Rotation at CI-2 canbe testedwiththeheadfully flexed.
The lateraljointsareflatinthecoronalplane,slopingdownwardandlaterally fromthebase of thedens,butinthesagittalplanethefacetsof Cl andC2areboth convex,making them incongruous. The incongruity is further increasedbythe greater centralthicknessofthearticularcartilages. The gapsbetweenthe anterior and posterior parts of thefacetsarefilledbylarge,vascular,fat-filledsynovialfolds(Figure1-4). These triangular meniscoidinclusionsareattachedat their basestothe inner aspectofthefibrouscapsule,and their inner surfacesarelinedbysynovial membrane. These vascularfatpadsaresoftandchangeshapereadily,movinginand out ofthe jointsastheheadisflexedorextended;however during veryrapid movements (e.g., whiplash),theyarevulnerabletobruisingastheyare nipped betweenthefacets. The posterior synovialfoldsaremostofteninjuredinextension injuriesr" .
Awell-definedfibrouscapsule,about1to2mmthick,is attached around thearticularmargins. The rootsofthesecondcervicalnerveleavethespinalcanalcloseto the posteromedial capsule. They joinasthespinalnervepassestransverselybehind the posterior fibrouscapsule,inwhichthelargedorsal root gangliondwarfsthesmall anterior root. The largedorsalramusformsthe greater occipitalnerve,whichhooks under the inferior obliquemuscletoascend through thesemispinaliscapitisinto
the posterior scalp.26,27 It canbe palpated about 1em lateral to the external occipital protuberance.
The inferior oblique musclepasses transversely from transverse processofC1to the spine of C2, enclosing aspace immediately behind the lateral atlantoaxial joint (Figure 1-4). This space behind CI-2 contains theC2nerve, surrounded byaplexus oflarge, thin-walled veins. These thin-walled veinsmaybe injured in whiplash, forminga hematoma around the C2nerve that may track along thenerve. Lateral to the lateralmassesof Cl andC2,the slightly tortuous vertebral artery is loosely attached tothe joint capsule;its tortuous vertical course allowsfor stretching during flexion.
The central part of the atlantoaxial joint complex is formed by the articulation of thedenswiththe anterior archof the atlasandthe enclosure of thedensby the strong transverse ligament, whichpasses between large tubercles onthemedialaspects of the lateral massesoftheatlas. Articular cartilage coversthe articulations, and there are separate synovialcavities between the densand the archand between the transverse ligament andthedens. From near thetipofthedensoneachside, strong alar or "check" ligaments upwardand outward to tubercles onthemedial margins of the occipitalcondyles. 8 A much finerapical ligament passes from thetip of the densto the anterior margin of the foramen magnum, andan inferior longitudinal bundle passesfromthe transverse ligament tothebackof the body of C2, completing a cruciate ligamentous complexcovered behind bythe membrana tectoria and the anterior duramater. The skullandatlas rotate around theaxisof the dens,anexcessive movement being checked by the alar ligaments, which maybe injured in rotational strains. Upper cervicalflexion extension movements are shared almost equally between the congruous atlantooccipital joints andthe incongruous lateral atlantoaxial joints as the incongruity between the reciprocally convex lateral massesof Cl andC2allows rocking with flexionand extension inthisjoint. 20
loWER CERVICAL SPINE (C3- T1)
Vertebrae. Cervical vertebrae havethe smallest bodiesand the largest spinalforamina of the vertebral column (Figure 1-5). The C3to C6 vertebrae are described as"typicalcervical vertebrae," but C6isatypicalinsome respects, havinga longer spinous process than C3toC5and prominent, palpable anterior tubercles called carotid tubercles onits transverse processes.Atypicalcervical vertebra hasasmall vertebralbodywhose upper surfaceisflat centrally but is shaped likea seat with side supports (uncinate processes)andwhose lower surfaceisconcaveinthe sagittal plane (Figure 1-5). From the posterolateral "comers" of this vertebral body,the thin pedicles project posterolaterally. From the pedicles, thin laminae are sharply angled posteromedially to enclosealarge triangular spinal foramen. Short bifid spinous processesextendbackfromC3toC5. The spinous process of C7is long and pointed, projecting prominently atthebaseof the neckso that C7iscalled the vertebra prominens. The spinousprocessofC6isusually not bifid,anditis intermediate in length between those ofC5 andC7. Usually all the spinous processes between C2andC7are readilypalpable,especiallywith the patient supine andmusclesrelaxed. With care, eachspinousprocesscanbe idenrified.i"
Lateral tothe junction ofthepediclesandlaminaearethe articular masses, with articular facetson their upper andlowersurfaces. The upper facetsare directed upwardandbackward,andthelowerfacetsare directed forwardand downward (Figures 1-4and1-5). These facetsareflatandformsynovial zygapophyseal joints with the facetsofthe adjacent vertebrae. The articular massesfromC3to Tl form bilateral articular columns that beara significant proportion of axial loading." Once again,facet
Figure 1-5
Typicalcervicalvertebraasseenfromabove. The C3toC5 vertebrae eachshowasmall vertebralbody,bifidtransverseandspinousprocesses,alarge triangular spinalcanal,and zygapophysealfacets,whichlieinanobliquecoronalplane,at45degreestothelongaxisof thespine.
jointlevelscanbeidentifiedbypalpation,C2-3beingparticularly prominent, and other levelsareidentifiablewithreferencetothepalpablespinousprocesses.
FacetAngles. The cervicalzygapophysealfacetsaredescribedas"lyinginanobliquecoronalplane."t7 Milne'" measuredtheanglebetweenthefacetsandthesuperiorsurfaceofthecorrespondingvertebralbodyin67humanskeletons.Hefoundthe anglestorangefromanaverageof127degreesatC5to116degreesatC7and112 degreesat Tl. Consideringthatthesuperiorsurfaceofeachcervical vertebral body slopesdownwardandforward,thesefindingswould correspond toanglesvarying fromabout45degreestothelongaxisofthespineinthemidcervicalspine,reducing tojustover30degreestothelongaxisofthespineat Tl. In sagittalsectionsofadult cervicalvertebrae,wefoundtheseanglestovaryconsiderably,but45degreesisclose to theaverageinthemidcervicalspine,and30degreesisclosetotheaveragefor Tl.
The transverseprocessesprojectanterolaterallyfromthefrontofthearticular massesandthesidesofthevertebralbodiesastwoelementsenclosingforaminatransversariaforthevertebralarteries(Figure1-5). The anterior costal element ofthis transverseprocessprojectsfromthevertebralbody. The posterior,ortrue,transverse elementprojectsfromthearticularmass.EachtransverseprocesshastwosmalltuberclesatitstipintheC3toC6vertebraefor attachment ofthescalene musclesscalenusanteriortothe anterior tuberclesandscalenusmediustothe posterior tubercles. The uppersurfacesofthetransverseprocessesareconcaveor gutter shaped forthepassageofthecervicalspinalnerves. These guttersarewiderfromC5down, correspondingtothelargesizeofthedorsalrootgangliaandnervesformingthebrachialplexus,whichpassesoutbehindthevertebralarteryintotheinterscaleneplane intherootoftheneck.
The atlas,axis,andC7areatypicalcervical vertebrae. The C7 vertebra hasa long spinous processand more vertically oriented zygapophyseal facetsandlacksan anterior tubercle onits transverse process. The C7 transverse process hasasmall foramen, but itdoes not transmit a vertebral artery, only a vertebral vein. There isa gradual transition fromthe 45-degree angle of typicalcervicalfacetsto the 20-to 30-degree angle of thoracic facets.
Vertebral Arteries. The first part of the vertebral artery risesfromthe subclavian artery andpasses upward on longus collito enter the foramen transversarium of C6. The second part ascends through C6to Cl inclusive, accompanied bya vertebral venousplexusandaplexus of small sympathetic nerves. The third part curves behind the lateral mass of CIon toits posterior arch. The fourth part pierces the dura and arachnoid to enter the cranial cavityand the subarachnoid spaceatthe foramen magnum. 31 • 32 Within the cranialcavity, the two arteries ascend between the base of theskullandthe medulla inthe subarachnoid spaceandjointoformthe basilar artery atthelevel of the pontomedullary junction. The! areusually asymmetrical to some degree. From a study of 150cadavers, Stopford ' claimed that 51% showed the left artery tobe larger than the right, 41% showed the right artery tobe larger than the left,and only 8%of the leftand right arteries wereequalinsize. In an unpublished study basedon measurements of the arterial imagesin magnetic resonance (MR)scans of 267 patients, Kearney'? found the left artery tobe larger in49% of patients, the right artery tobe larger in29% of patients, and approximately equal in22% of patients. These findingshave relevance inpassive movement and manipulative studies. When there isgrossasymmetry, there maybea greater risk of depriving the hindbrain of its blood supply from maneuvers that obstruct the larger vertebral artery. 10 Vertebral artery injury is relatively rare in motor vehicle trauma, except insevere fracturedislocations, but wehave observed asmall number of instances of intimal damage with dissection and formation of loose inner flapsin traumatized arteries after motion segment subluxation in motor vehicle accidents. In survivors of such accidents, vertebral artery thrombosis islikely.
The vertebral arteries within thecervical spine give off small branches to supply the vertebrae anddeepmusclesandafewsmallfeederstothe arteries of thespinal cord,themain arteries tothe cord (one anterior andtwo posterior) deriving from the terminal portions of the vertebral arteries within the cranial cavity. Each vertebral artery suppliessmall branches at the level of C2, which formspiral arteriolar "glomeruli." (These glomeruli enter ampullary veinsbelow the base of theskullin the suboccipital region.") These small arteries, which connect directly to large veins, havearich autonomic nerve supply that controls blood flow. Injuries that paralyze their nerve supply couldcause arteriovenous fistulae.
The vertebral veinshave plentiful connections with segmental neck veinsand withthe internal vertebral venous plexusinthe epidural space. The epidural venous sinusesarelargeandvalveless,so blood from their connecting veinscanflowindifferent directions within them (i.e., into the basivertebral veins of the vertebral bodies). Therefore theseveinsactas routes forthe spread of cancer cells-usually to thoracic or lumbar vertebrae.
Motion
Segments. Each lower cervical mobile segment consists of "interbody joints" (an intervertebral discandtwo uncovertebral joints) andtwo zygapophyseal (facet) joints. The subaxialcervical mobile segments havean average of about 15 degrees of sagittal range per mobile segment compared toanaverage of about 10 degrees per mobile segment inthe lumbar spine. 3 • 36 These ranges of movement depend
Figure 1-6
Factors controlling movementrange. The slendernessofcervicalvertebraeandtherelative thicknessofthediscsfavormobility. An index of discthicknessoverthe anteroposterior diameter (APD) ofthevertebralbody (VB) ishighestinthecervicalspine (C), nexthighestin thelumbarspine (L), andlowestforthethoracicspine (T).
onthethickness of the intervertebral discs relative tothe horizontal dimensions of the vertebral bodies (Figure 1-6). The dimensions and compliance of the intervertebral disc determine the amount of movement possible;the extent and orientation of the zygapophyseal articular surfaces control the types of movement possible andmakean essential contribution to stability by restraining excessive movement.
Van Mameren etal 37 showed that inlivingsubjects, the range of activecervical motion inthesagittalplanecouldvary considerably depending on variation intheinstructions giventothesubjects. The complex interplay of softtissue restraints and other factors resulted inthesamesubjects moving through different ranges insuccessive attempts to perform essentially thesame movement.
Specialfeatures of lowercervical mobile segments include the development and natural history of the nucleus pulposus;the growth of uncinate processes, formation of uncovertebral joints,anddiscfissuring; the orientation of zygapophyseal facetsat 45degrees to the long axis of thespine;andthe age-related formation of uncovertebral osteophytes encroaching onthe intervertebral canals together with barlikeposterior disc protrusions into thespinalcanal.
Development and Natural History of the Nucleus Pulposus, The nucleus pulposusisformedfromthe interaction of notochordal cellsand the surrounding loose connective tissue of thedisc. The notochordal segments makea much smaller contribution incervicaldiscsthanin thoracic or lumbar discs. The rapid growth of notochordal segments and their interaction with the surrounding disctissuesformsalarge, soft gelatinous massatthe center of each lumbar intervertebral disc. In cervicaldiscs the notochordal segment may remain smalland rudimentary at birth; the cervical nucleus of infants and young children oweslessto the notochord than tothe lumbar disc,andthecervical nucleus contains more collagen than the lumbar nucleus.l 'r'"
The more dramatic regional differences between cervicaland lumbar discsare duetothe growth of cervical uncinate processes (Figure 1-7)andthe formation of uncovertebral cleftsinthecervicaldiscs of children. This leadsto horizontal fissuring of thecervical nucleus and posterior annulus fibrosus (beginning in young adults),sothe nucleus pulposus of cervicaldiscshasa relatively brief existence (in childhood and young adults)asasoft "encapsulated nucleus" enclosed byan intact fibrous andcartilaginous envelope. With the advent of fissuringinearly adult life,soft nuclear ma-
terialmay"dryout"orbemaskedbybecomingenmeshedinaplentifulcollagenous network.Discsalsodevelopregionalcharacteristicsinresponsetodifferentfunctional demands.Cervicaldiscsbearlessaxialloadthanlumbardiscs. Proteoglycan andwater content relatetoloadbearing,andproteoglycan concentration islowerincervical discsthaninlumbardiscs.38
Therefore thecervicaldiscshouldnotberegardedasasmallerversionofalumbardisc. It isvastlydifferentinmanyrespects. It haslesssoftnuclearmaterial,inchildrenandwhatremainsisenmeshedincollageninadults,withuniversalfissuringof cervicaldiscsinadults. Nuclear prolapseislesslikelythaninlumbardiscsexceptin severetraumaticincidents,whenherniated,cervicaldiscmaterialismorelikelytopass backwardintothewidespinalcanalthantopasslaterally through the uncovertebral jointsintothe intervertebral canals. Lumbar discstendto herniate posterolaterally aftertraumatic rupture oftheannulusinrelativelyyoungadults,butitismoreusualfor thealready-fissuredcervicalannulustoshowageneralized,barlike posterior ridgeas atransverse,annular,andosteophytic protrusion intothespinalcanal,seeninmiddleagedorelderlycervicalspines.
Growth of the Uncinate Processes: the UncovertebralJoints ofLuschka. The lateralpartsofacervicalvertebralbodyareformedbyossificationfromtheneural archcentersofossification, not fromthe centrum. The widthoftheinfant intervertebral discdoes not extendtothewholetransverseextentofthe vertebral body. The outeredgeoftheannulusissaidtoreachjustlateraltothelineoffusion ofthe centrum andvertebralarches.Fromthe upper lateralbordersofeach vertebralbody,processesgrowupwardtowardthevertebralbodyabove,inthe loosevascularfibroustissueatthelateralmarginsoftheannulus."Eachprocessor uncushasgrownenoughby8yearsofagetoformakindofadventitious"joint" calledthe uncouertebral joint, or cleft, oneachsideofthedisc(Figure1-7). There is somedoubtasto whether thisjointorpseudarthrosisdevelopswithintruedisc tissueorwhetheritar.rearsasacleftinthelooserconnectivetissueimmediately lateraltotheannulus.' ,36,39 Looseconnectivetissueinthislateral interbody space
Figure 1-7
Anteriorviewofcervicalspineshowstheunique shapeofcervicalvertebralbodies,whichhave uncinateprocesses (UP) projecting upward from their lateraledgestoform uncovertebral "joints" withthevertebraabove.
maybeformedintoannularlamellaebeforethe uncovertebral cleftsappear. The formationoftheuncuseffectivelynarrowsthelateral interbody spacesinwhichthe translatory movementsaccompanyingflexion,extension,and rotation takeplace. It "concentrates" theplane of sheartoa narrow horizontal bandwithinthelateral annulus. When thecleftsappearinadolescence,thetip of theuncusandthegroove inthelateralmarginofthe vertebra aboveareobservedtobelinedbya fibrocartilage that isprobablyderivedfromthe horizontally cleft outer annulus whoselamellaeare bent outwardandcompacted together; athinfibrous"capsule" limitseachcleft laterally.'t"
Ceroical Disc Fissuring. The same shearing movements that resulted in uncovertebralcleftformationinadolescentsresultsinmedialextensionof horizontal fissures intothenucleusand posterior annulusfromthe uncovertebral cleftsin young adults (Figure1-8).Atfirst,thesefinefissuresaredifficulttoobservein postmortem discs fromadultsin their twenties,exceptafter injection of contrast intothenucleusinlivingsubjectsorIndianinkintothe center of postmortem discs,whenspread through thefissuresintothe uncovertebral cleftsisobserved.However,bythetimeaperson isinhisorherlatethirties,thesetransverse posterior fissuresaremoreobvious,extending right through the posterior part of theadult intervertebral discbetweenthe two uncovertebral joints,leaving onlr the anterior annulusandthe anterior andposterior longitudinal ligaments intact" ,18,40-43 (Figure1-9).
Suchextensivefissuringchangesthecervicaldisc in middlelifefroma structure that deformsaroundacentralnucleuson movement, toa bipartite discwitha"gliding joint"betweenits upper andlowerparts,whichallows translation ofseveralmillimetersforwardandbackwardinfullflexionandextension(Figures1-8and1-9). This arrangement isrelatedtothewiderangeof mobility ofthecervicalspine,whichentails muchlessstabilitythanthe thoracolumbar spine.Becausethe anterior annulusand longitudinal ligamentsaretheonly intact partsofmostcervicaldiscsinadultsover35 yearsofage,thecervical motion segment isheavily dependent onthe integrity ofthe zygapophysealjointsand posterior musculature andligamentsforitsstability. The additionalloadingofthe uncovertebral joints that accompaniesdiscfissuring,lossof
Figure 1-8
This diagramofanormaldiscogramfroma36-year-oldwomanshowshow contrast, injectedcentrally,typicallyspreadstransversely through linearfissuresinthe normal discinto bothuncovertebraljointsinwhichexpandedcavitiesallowdiffusespreadofthecontrast.
Figure 1-9
This diagramistracedfromasagittalsection of a normalelderlycervicaldisc,nearthemidline.Itillustratesthetransversefissuring,whichisanormal featureofmostadultcervicaldiscs;the posterior half of thedisciscompletelyfissured;onlythe anterior annulusandthelongitudinalligamentsremainintact.
nuclear material,and"disccollapse,"leadstolateral osteophytosis fromthe uncinate processes into the intervertebral canals (Figure 1-10). In someindividualsthese osteophytesareverylarge;theyseverely limit thespaceavailableto the spinalnervesand maycompressthe anterior part of thespinalcord. 44 • 45
Zygapophyseal Joints. Bythe orientation of their articular facets,zygapophyseal joints determine the directions of intervertebral movements. Their articular surfaces are oriented at about 45degreestothe long axis of thespine, with a range of 30 to 60 degrees." The cranialfacetsare directed upwardandbackward;thecaudalfacets are directed downwardandforward. The facet orientation facilitatessagittal plane movements and requires that axial rotation andlateral bending arealways coupled. The joint capsulesarelax, permitting great mobility.36,46 In our studiesofsagittal sections of more than 200 cervicalspines of people of allages,wehavefound that the lateral joint capsuleislaxandfibrous;itis partly formedbythe ligamentum flavum anteriorly,butthe posterior capsuleisverythin,andthelarge triangular fatpadatthe lower posterior joint margin isenclosedbythe insertions ofthedeep multifidus muscles that wraparoundthe articular column. Where the upper endof the joint adjoinsthe intervertebral canal anteromedially, thecapsule contains verylittlefibrous tissueandisformedbythesynovialfatpad that projects into thejoint.Vascular,fatfilledsynovialfolds project between the articular surfacesfromthe upper andlower joint recessesas "meniscoid inclusions," whichare vulnerable to bruising or rupture inwhiplashinjuries, forming facet joint hemarthroses (Figure 1_4).18
In flexion,acervical vertebra both tiltsandslidesforwardonthe subjacent vertebra,with ventral compression anddorsal distraction of thedisc, "spreading thespinousprocesseslikea fan.,,46 Forward rotation and translation probably occur together, but]ones47 maintains that theforwardslideismost evident inthe later stages of flexion. In fullflexion, there mayonlybeabout5mmoffacetal contact remaining." Lateral radiographs oftheflexedcervicalspineshowa "stepped" arrangement of the vertebral bodiesbecause of theforwardslide(an appearance that might beassociatedwithinstabilityifobservedinthe lumbar spine but regarded as normal intheflexedcervical spine). With rotation of15degreesor more, there is about 2mm of translation. Thereforethe centers of motion forsagittalplane movements are located in the subjacent vertebra. These centroids arerelativelylowinthe vertebral body for upper subaxial segments andrelativelyclosetothediscin cervicothoracic segments. 36
Uncovertebral andfacet osteophytes
Figure 1-10
Obliqueviewsof normal andarthriticvertebrae. These anterior obliqueviewslookalongtheintervertebralforaminaandshowthe largedorsalandsmallventralroots ofthecervicalnerves emerging betweenthezygapophysealand uncovertebral joints. Note the reducedspaceforthenerveswhen uncovertebral andfacetosteophytesappear.
The orientation ofthecervicalfacetsandthe presence of uncovertebral joints both contribute totheprocess that leadsto shearing and posterior fissuringinadult cervical intervertebral discs. These changeswould appear tobethepricepaidin reducedstabilityforthe required rangeofcervicalmobility. The reduced stability infullflexion,whichdependson maintenance ofafew millimeters of facetcontact,obviouslyrequiresthe strength and integrity of the posterior musclesand ligaments.
Degenerative Pathology. Discfissuringinvolvesthe posterior parts of thediscand extendsbetweenthetwo uncovertebral jointsoneachside, but the posterior longitudinalligament usuallyremainslargely intact," Isolated disc thinning isa common degenerative phenomenon, especiallyinC4-5,C5-6,or C6-7. When theuncuscomes tobearmoredirectlyandfirmlyonthelowerlateral margin of the vertebra above,the "articular surfaces"ofthese pseudarthroses become weightbearing andthe uncinate processesgrow posterolaterally directed osteophytes. Uncovertebral osteophytes frequently project intothe intervertebral canalsin middle-aged and elderly cervical spines. Anteriorly directed osteophytes fromthezygapophyseal superior articular facetsarealsoquite common inelderly subjects/"
Disc thinning is accompanied by posterior bulging of thediscasabar projecting into the anterior epiduralspace. The uncovertebral osteophytes appear toextendmediallyalongthe posterior discmarginsso that thediscbulgeis accompanied by marginal osteophytes aboveandbelow. The structures vulnerable to compression ordistortion asa result of thisdegenerativespondylosisarethecervicalnerveroots,the vertebral arteries,andthespinalcord.
CervicalNerveRoots. The lateral recessesof the spinalcanalare wider inthecervicalspine than inthe lumbar spine but the lowercervical intervertebral foramina are almost filledby the largecervicaldorsal root ganglia. The nerve roots andgangliapass through the foramen atorbelowthelevelofthe uncovertebral and zygapophyseal joint lineswith the large sensory roots aboveand behind the small motor roots. The lumbar dorsal root ganglia,by contrast, occupy the uppermost parts oflarge intervertebral canals under thepedicles. Lumbar nerve roots are more atriskof entrapment inthelateralrecessesof the lumbar spinalcanal, but cervical nerve roots are more at riskofclose confinement or entrapment in the intervertebral foramina bya combination of uncovertebral andfacet osteophytes (Figure 1-10). They areliabletobe squeezedin pincer fashion between the zygapophyseal and uncovertebral osteophytes or squeezed downbythe encroaching osteophytes into the lower part of the intervertebral foramen.
Spinal Cord. The posterior bars formed bydisc protrusions, flankedby marginal osteophytes, project into the anterior epidural space. The cervicalspinalcanalisfortunately relatively largeinits anteroposterior diameters, ranging from13to22 mm in midsagittal diameter between C3andC7,witha mean valueof about 17mm. 29 The spinalcord normally occupies about 60% of this anteroposterior space.l? However, in the extended position, particularly with degenerative changes in the lowercervicalregion,the combination of disc protrusion and posterior infolding or buckling of the dura and ligamenta flavamay imperil thecord. In elderly women with thoracic osteoporotic kyphosis,the upper thoracic kyphosis requires a compensatory cervicallordosis that further narrows the spinalcanal.
In postmortem examinations of thecervicalspines of elderly subjects,we often findthe anterior surface of thespinal cord tobe permanently indented bydiscandosteophytic bars. These mayexist without producing recognized symptoms. However, incervical injuries, suchsubjectsare more vulnerable tospinalcorddamage than young subjects.I''
Vertebral Arteries. Laterally directed uncovertebral osteophytes also encroach on the course ofthe vertebral arteries, making the originally straight arteries tortuous. They areoften,in addition, observed tobe thin walledand dilated in elderly subjects. Suchsubjectsareoften osteoporotic. This combination of changes wouldmakecervical manipulation potentially hazardous in elderly subjects. 10
ANATOMY OF CERVICAL INJURIES
MECHANISMS
In flexion,the posterior elements (facets)are distracted and the anterior elements (discs)are compressed. In extension,the anterior elements are distracted and the posterior elements are compressed. The cervicalfacet orientation means that translation accompaniesthese anterior and posterior rotations, with shearing forcesinthetissues of the motion segments. Flexionor extension injuries are often accompanied byaxial compression, especiallyin motor vehicle trauma. The cervicalspineis quite well protected against flexion injury by the bulkofthe strong posterior cervicalmuscles. In contrast, there areonlyafewsmall anterior musclesto protect against extension. The longuscollietcerviciswiththe prevertebral fasciaissmallin bulk compared to the posterior musclesand their fasciae. Slender necksare more vulnerable to injury than thicknecks. Therefore whiplash symptoms more often leadto chronic pain syndromes infemales than inmales.Flexion injuries, with single-level fracture dislo-
cation,aremore commonly seenthanextensioninjuriesinspecialistspinalinjuries units.Incontrast,inclinicalpracticeaclinicianseesextensioninjuriesmoreoften.
Extensioninjuriestendtobe multisegmental, especiallyinvolvingC5-6andC6-7at thelowerendand CI-2 andC2-3atthe upper end.
NATURE OF EXTENSION INJURIES IN SEVERE WHIPlASH OR FROM CRANIOFACIAL IMPACTS
Extensioninjuryfrequentlycausestransversetearsofthe anterior annulusatthediscvertebralinterfaceasaresultof anterior distraction andshear, without rupture of the anterior longitudinal ligament that remainsintact. This mayoccurinseveral discsbecausetheforcesareabsorbedpartiallybyeachdisc. More severeextension injuriesmaypartiallyavulsethediscfromthevertebralmarginwith tearing ofthe anterior longitudinal ligament. The small anterior musclesarethelast structures to tearbecausetheyaremore compliant and stretchable thanthe anterior annulus, withthe anterior longitudinal ligament intermediate initscapacityfor stretch. Atthe sametime, posterior compressionofthe articular columnsbruises the vascular,intraarticular synovialfolds;damagesthe articular cartilages;orfracturesthetipofa facet,whichisforcedagainstanadjacent vertebral arch. In theacute injury onemay observefacet joint hemarthroses. Suchinjurieshavebeen commonly observed during autopsyafterfatal motor vehicleaccidents. They mayalsobe demonstrated ifmagneticresonanceimaging(MRI)isdoneattheacutestage, although MRI is not sensitiveenoughto demonstrate allthelesions. In posttraumatic chronic pain,facetpain ismore common thandiscpain,andthepainfulfacetmayshowsigns of arthropathy onabonescan.
Wehaveobservedinmanyfatallyinjuredindividualssubjectedto violent movementsinbothflexionandextension, that themaininjurieshavebeensustainedin extension. This relatestothe inadequate protection givenbyseatheltsin head-on collisions,inwhichthemajorityofdriversandfrontseatoccupants of carsinvolvedin high-speed collisionsstrike their headonthe steering wheelorsome other part ofthe carandsustainacraniofacialtraumawithaneckextensioninjury. More than90% of theseindividualsshowdiscinjuries,and about 80%alsoshowsofttissueinjuriesto thefacetjoints. Nearly 15%alsoshow intraneural bruisesinthedorsal root ganglia.6.4t .42.49.50
UPPER THORACIC AGING AND INJURIES
The questionoftenarisesasto whether interscapular painiscausedbythereferral of painfromtheneckorbylocalpainfrom pathological conditions in thoracic segments. In postmortem studiesofthejunctional cervicothoracic region, there isamarked contrast betweenthespondylosisobservedinC5-6and C6-7, withdisc thinning or even spontaneous fusionacross degenerate segmentsandthegood preservation of the adjacent upper thoracicsegments. This probably relatestothe greater stiffnessofthe upper thoracicsegmentscausedbythe short sturdy ribs of the upper ribcage. However, radiographic findingsoftenshowwidespreadthoracic degenerative changesin midthoracicandlower thoracic segmentsinmiddle-agedsubjects, sometimes related totheso-called Scheuermann's disease.
Upper thoracic segmentsalsoshowinjuriesaftersevere trauma." In flexioncompressionoraxialcompressioninjuries,the anterior elementsshow end-plate fractures, bonebruisingcausedbymultiple trabecular microfractures, or vertebral wedgingor burst fracturesinmoresevereflexion compression injuries. These vertebral injuries areaccompaniedby bleeding intotheadjacentdiscs,whichshowless direct injury
thaninthecervicalspine(exceptforthe upper two thoracic discs,whichmayshowinjuriessimilartothecervicalspine).
In thethoracic articular columns,facetinjuriesarealmostas frequent asinthe cervicalspine. 43 There isanadditionalrisk of facettip fracture becausesmallridges ofbone jut outfromthe thoracic laminaebelowthe inferior recesses of the thoracic zygapophysealjoints;inextensiontrauma,an inferior articular processmay impact on thisridgewithdamagetothefacettip.
INNERVATION OF CERVICAL MOTION SEGMENTS
INTERVERTEBRAL DISC
The longitudinal ligamentsandtheannulus of cervical intervertebral discsare innervatedfromtheventralrami, sinuvertebral nerves,and vertebral nerves (around the vertebral arteries).AccordingtoBogduketal,5Ionlythe outer annulusis innervated, but Mendel etal52 demonstrated nerves through thewholethicknessoftheannulus. Nervesare not foundinthecartilageplatesorinthenucleuspulposus of normal discs.
ZYGAPOPHYSEAL
JOINTS
The medial branch ofeachdorsalramus contributes tothe innervation oftwozygapophysealjoints.27 ,53 The medialbranchesofthe C4 toC8dorsalramicurvedorsally around thewaistsofthe articular pillars. There areoftentwoofthese branches on eacharticularpillar. They supplythezygapophyseal joint capsulesaboveandbelow andinnervatethe corresponding segments of multifidusandsemispinalis. The fibrous capsuleandjointrecessesare innervated, but the ligamentum flavumdoes not appear tohaveanynociceptivenerves. 54-56 The synovialfolds projecting into thejointsfrom thepolarrecessesare probably innervated. Innervation has been demonstrated in these structures inthe lumbar spine. 55,56
Painmayarisefrom injury toany innervated part of the motion segment. It may alsoarisefrominjurytospinalnervesordorsal root ganglia,whichareclosely related tothesejoints. For example,thedorsalrami of C2andC3,whichform the greater occipitalnerveandthe third occipitalnerve,canbeaffectedbyinjury. They supplythe skinofthemedial upper neckandtheoccipitalscalpasfarasthevertex. They also supplyrostralsegments of postvertebral musclesandthe posterior capsules of thelateralatlantoaxialjointsandtheC2-3and C3-4 zygapophysealjoints.Wehaveobserved both perineural and intraneural bruising in our postmortem studiesofneckinjuries. 50
PAIN REFERRAL PATTERNS
Painisoften referred totheskin, but painisalso referred through the sensory nerves of muscles.Trapezius, sternomastoid, andlevatorscapulaeare innervated byC3and C4,the rhomboids byC5,andthe short scapulohumeral musclesbyC5andC6;the longer trunk-humeral muscleshave multisegmental innervation (C5to Tl). When thesemusclesareinjuredorinvolvedinreflexspasm,theymay generate patterns of referredpainsimilartothoseofthe underlying spinaljoints. 57 Explaining cervical headache,Bogduk'?pointstothe convergence ofafferentsfrom Cl-3 withthespinal tract ofthe trigeminal nerveinthegray matter ofthe upper cervicalcord,inthe "tri-
geminocervicalnucleus." The ophthalmic andmaxillarydivisionsofthetrigeminal nervearebest represented inthis"nucleus."
Twonecksprainsyndromesaredescribed:a "cervico-encephalic syndrome" in whichtraumatouppercervical motion segments(e.g.,discs,facets,muscles,ordura) causesneckpainandheadaches,anda"lowercervical syndrome" from traumatic lesionstolowercervical motion segments,inwhichpainradiatesfromthenecktothe upperlimb,shoulder,orscapularregion. 5860
SUMMARY
The uniqueanatomyoflowercervicalsegmentsgivesthecervicalspineawiderange ofmobilitybutcarrieswithittheriskoflessstabilityinthesemobilejoints. The orientation ofthecervicalzygapophysealjointsat45degreestothelongaxisofthespine andthe childhood growth of uncinate processesleadtothe development ofuncovertebralclefts,progressingtoearlytransversefissuring of cervical intervertebral discsin youngadults, through thenucleusand posterior annulusfibrosus,withloss of the "encapsulatednucleus"foundinlumbar intervertebral discs. This is frequently associated,inmiddle-agedandelderlyadults,withloss of disc height inthemidcervical andlowercervicaldiscsandwiththe development of uncovertebral osteophytes, whichpose threats tothecervicalspinalnerves. Spontaneous fusionoflowercervical segmentsmakeselderlypeoplesusceptibleto upper cervicalinjurieswithrisktothe spinalcord.In younger individuals,therelativeinstabilityofthesemobilecervical segments,andthelackof strong anterior protective muscles compared to thoracolumbar segments,increases their vulnerability toextensioninjury.Tearstotheanterior annulusandinjuriestothecapsule,synovium,and articular cartilagesofcervical zygapophysealjointsare common sequelaeofseverewhiplash.
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Biomechanics of the Cervical Spine
Nikolai Bogduk
Fundamental to the understanding of disorders of an organ isa knowledge of its normalphysiology.Sucha body of knowledge existsfor organs suchasthe heart, thekidneys,andthelungs. Consequently, the causesand consequences of cardiac failure, renalfailure,and respiratory failurecanbe understood in terms of the normal function of these organs, and subsequently, treatment canbe instituted ona rational andvalid basis.
Suchabody of knowledge does not existfor the musculoskeletal system. Some appreciation has emerged of the physiology of the lower limbs through gait analysis, but there isno information of comparable standard for the vertebral column.
Biomechanics is the firststepto determining the physiology of the musculoskeletalsystem. When the principles of engineering are applied and mathematical analysesareused,thewayin which a mechanical system operates canbe determined. However,the more complicated thesystem, the more laborious and difficult isitsanalysis andthe more complicated the result seems.
The firststageof biomechanical analysisisthe study of kinematics-observing and measuring howthesystemmoves. The second stageis kinetics-determining the forces that operate onthesystem(to produce the observed or observable movements). With respect to the cervicalspine,the study of kinetics is subsumed in the field of mathematical modeling. The intricacies and detail involved render mathematical modeling of the cervicalspinea complex and difficult field.
The literature is limited and quite demanding. Interested readers are directed to certain seminal'"? and cornprehensive't-' publications. This chapter is restricted to the kinematics of the cervicalspine.
ATLANTOOCCIPITAL KINEMATICS
The atlantooccipital joints are designed toallow flexion-extension but to preclude other movements. During flexion,the condyles of the occiput roll forward andglide backward in their atlantial facets;in extension, the converse combination of movements occurs.Axial rotation and lateral flexion of the occiput require one or both oc-
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own memories and vague comments. He made light matters of all the heavy affairs of business, of family, of care of any sort. He wore the cleanliness and freshness of his linens as if he imparted these qualities to them, as if he yielded these qualities with his easy, careless gestures and uncommitted mood. Gone from her, he kept always in Theodosia’s mind as that which lent grace to any morning into which it might come, into any evening, any memory, so that she smiled faintly if she thought of him. She knew his delicacy in some harsh way, in some hard framework of knowing that lay over her momentary joys in his radiance, in his beauty. Once, into the midst of the intoxicating vapor which surrounded her sense of him, her own voice spoke aloud, surprising her with its casual finality:
“He’d follow after the last lovely face offered”—and added: “The trick around the eyes and he’d go.”
If he were coming she would wear the pale yellow dress he admired and arrange her hair in the way he most praised, a low knot drawn above her neck and pushed securely into the curves at the back of her skull. Knowing that he would come she would linger over the hair, a thought of him and of his gracious, easily given admiration in every lift of the comb as she gently tooled the mass into shape and smiled now and again at her long face with its firm thin red lips. She had read from her grandfather’s books and Frank had brought her books containing the new learning. Conway’s knowledge was more powerful with her, she knew, and she smiled at her curving smile until her own lips told her their subtle learning, over and over, retelling. Conway would seat her in the chair of the blue brocade and he would adjust the light to fall in a cascade on the yellow gown, or he would arrange the bowl of roses with some reference to herself and himself and then sit negligently in his chair, himself a part of some whole which he at the same instant encompassed, having no notion of why he did these things. Or did he have no notion? she argued. His knowledge would spread through the room, through the house, gathered to the brilliant constellations that swam in a sun-shaft of light before a window, the
motes of the beam, and gathered again to the scent of the honeysuckle outside on the chimney.
ALBERT would come heavily into the parlor although his feet were agile and his large frame was light to his motions. He filled the parlor with his seriousness and with his ponderous future which circled about his agricultural studies. He would lay his pretexts out, this way and that, making his decisions in her presence, but if Conway were at hand he was more light and less committed, as if only Theodosia had his confidences, as if his approach to Conway were still by the way of the college they had attended, of the streets they now walked together, of the ball they sometimes tossed back and forth, the dogs they owned in common. His strong body, rich with blood and bulk, seemed about to burst from its clothing as he sat opposite the light, moving from time to time in his seat in an excess of vitality. If he bent over a printed page, his earnest eyes lowered to their drooping, his mouth caught in its relaxed, searching pose, his studious moment would give him back to his boyhood, even to childhood, and Theodosia would smile faintly beside her eyes, deeply under the flesh, in a moment of tenderness. Sometimes she would play for him the light music he desired, bent rhythms that paused over brinks and leaped with spasmodic passion to its fulfilment in another twisted measure, any sort so that it moved swiftly to its consummation and readily fulfilled its promises. She was contemptuous of his taste in melodies even when she wanted most to please him. He was a part of the rich insufficiency that surrounded her. “He looks just like Tramp,” she said one day as she mounted the stairway, and Tramp was a great mongrel, part Dane, part collie, that lived somewhere on the street.
“He looks exactly like Tramp,” she said. She was dressing for his coming, working her hair into the shapes Conway liked, her lips withdrawing from the tunes Albert wanted played. “Oh, Lord! his Leave Home Rags and his My Mandy Lanes” she said. Later she
would play them for him, plucking the strings quaintly and withdrawing them from their meanings.
When he had first come back from his agricultural college he had talked of a girl named Judith. He still wrote to her, but seldom spoke of her now. He would settle into his chair with a great sigh of content, turning the letter addressed to Judith over and over in his hands, a letter he had forgotten to mail. When he talked of himself he came immediately to the subject that most concerned the farmers, the success of the tobacco pool. Sometimes he seemed cautious as he handled some letter from Judith, turning it about, as if he clung to it. He would beg Theodosia to play the new song he had brought, for he had come then to have her play a song.
“Gosh, you’re the only girl in town can play,” he said. “Fiddle or piano, it’s all one to her. And works either single or double.”
“Lady broke. Bridle wise. A right good five-gaited saddle mare,” she said. She would withdraw behind the neglected thumping of the piano or the plucked strings, indifferent to the tune but willing enough to accommodate a caller. When she had embarrassed him she would laugh a low laughter and let her eyes close over the music as she trailed it off into some theme she liked.
“Lady broke.... I didn’t call you that,” he said heavily. “I didn’t say it.”
IN autumn it was reported that a musician was coming to Lester, a larger town ten miles away, to teach violin-playing there. Word was spread about that she would visit Anneville one morning each week if three students could be found for her there. Theodosia and two half-grown children made up the number, and the teacher came. She was a small dark woman, slight in form, quick in her ways, heavybrowed, ambitious to become a great teacher. Old Anthony Bell engaged her to come to his house, had sent for her as soon as he had heard of her presence in the town, and had talked with her in
the parlor, grown coherent, alert under the stimulation of the young woman. She made him remember his Heart Bowed Downs and his Trovatores.
Theodosia felt abashed before the superior skill and she drew her bow nervously over the strings at the test lesson. She was stifled into a few days of inactivity until the new gestures set within her. She must learn to hold the violin. To approach it with the bow. To observe the right angle. To listen to the tone and learn the acoustics of the instrument. Sometimes the dark woman would answer a question by playing a phrase, a skurry of phrases, and Theodosia was half afraid of these replies, knowing that she missed a part. Not virtuosity but good playing. The words sang in her mind and broke a new world into a firmament, a world fuller than the old. Theory, harmony, musical history, musical literature, technique, the legato, the perfect legato, the singing violin tone. The ragged chrysanthemums bloomed along the front of the house where the south sun shone, and the fallen leaves made every footstep clatter. The fields beyond the town, where they arose on the hills and were seen from the windows of the house, had lost their rough lines as they were turned under by the plow for the winter grains, were set in order for the next growing year. Her eyes, lifted from the strings, would rest far away on the hill field where the earth had been made new and where it ran perpetually now with her singing legato, the brown earth laid out brown in the autumn sun.
The music teacher came each week, her talk a bright flash from the world far outside. She talked in half with her music and with her quick hands, but her speech was crisp and clear. In her the master walked out upon the concert stage and worked his bow over the strings; she gathered intensely in her darkness and in the vibrant speed of her facile hands, her mouth easily turning, her strong slender limbs swaying, or she tapped the bow against her skirt as she told how the master played a movement. Her fingers were little brains secreting the music of thought. Around her a peculiar, scintillating half-brilliance spread like a fog of things half-known, half-sensed; it caught at the imagination and kindled it but gave it
insufficient fuel. The man and the instrument were one. An interpretation of life. Of mind, mood, thought, by the way of sound. Man is speaking here. His voice. Sound brought to high refinements, nuances, exquisite variations to make a speech for the spirit of man. The musician knew; she flashed out of her darkness. These were days of unsatisfied knowing. One could never have enough.
Or again, how a ship cuts the waves open and spreads them apart to roll up on her sides and follow after her in a long sweep of tilting water with a froth of foam melting on its crest, how the little tugs draw a ship across a harbor, four little tugs or three joined to a ship by a long cable that stretches tight, pulling the great lazy giant down a bay. Or the Goddess of Liberty, how she is green like beryl or like deep sea water, her bronze burnt with salt fog until it is brilliantly green, catching the light of the morning on the front of her body and turning it off in bright yellow planes, her great squat figure too round and ample for grace, squarely set on firm skirts, shortthighed, great-waisted, holding her plump torch, a great progeny, a myriad brood mothered under her plump skirts. She is brightly green in the morning sun with planes of yellow light; she is looking down the bay and across the Narrows and out to the sea.
These were inaccessible but not far, making a relation somehow with the lightness of autumn, the mild sting of the coming cold that could be felt in the early morning. Walking about the town Theodosia wore a bright new coat of rich dark colors and a small velvet hat with a bronze buckle. Conway had helped her to choose the hat, and his lightly spoken approval, gaily negligent, rested upon it all through the autumn and seasoned her whole being with a delicate warmth. A fire burned now in the parlor grate. At nightfall Siver, the black houseboy, was sent through the rooms to renew the coal and brush the hearths clean. Old Tony Bell sat nodding in the room across from the parlor, his room, where the bookshelves were seldom assailed and the books sank together into a solid warped mass. “She will learn to play great music,” he said, “a concerto. I heard it in Paris, the Brahms Concerto. It was, I recollect, a night in December. Let her learn, it won’t hurt her. I never thought my own
flesh and blood would master it. She’ll learn.” His bed stood against the wall that was farthest from the fireplace. He would sink often into the bed with unwanted satisfaction and fall asleep without consent, or he would arouse himself and take a brisk walk at twilight, stepping along the boards of the gallery.
Theodosia practised scales in single tones and thirds, working happily, blending them in her thought with the running autumn and the crisp frost, with the rich new color that had come to her garments in the coat and hat, in certain gowns she devised with her dressmaker, in her autumn stockings and a brilliant scarf. Jane Moore came sometimes to practise with the instruments, inaccurate as before but pretty in her gray fur and bright blue dress. She would laugh at the precision of the music teacher and clatter amiably on the piano, her eyes misty with her own prettiness and tender with the devotion of youth to youth. “You’re too sweet for words,” she would say to Theodosia as she touched the keys lightly, smiling over her shoulder. Her brown hair was softly rolled and centered into low knots. She would tinkle lightly at Albert’s songs, giving them a manner, Meet Me Tonight in Dreamland dribbling from her pert fingers.
Catherine Lovell had a bright red hat for the mid-winter, accented with an unsubdued cock’s feather that tilted and swayed as she walked, as she sat lightly moving in her chair. She went to the Seminary every day to teach, but in the evening she would run to Theodosia for a chat or a walk, or she would bring a gift of winter flowers from her mother’s small window garden.
Back would come the day for the fiddle lesson. The teacher would enter with a quick smile, tossing aside her coat and her hat. The piano note would cry out briefly under her quick hand and the gut string would follow, slipping and crawling into tune, Theodosia’s heart beating fast with some cruel, fearful pleasure. A skurry of runs and a trill and a few bars from the cadenza of some concerto. The example would clarify her words: each note must stand out like a star in a dark night.... Smoothness in the change of position when
the string must be crossed without sound.... The singing tone, the perfect legato.... The bow should be thought of as of indefinite length—no end to it, no break between the up-bow and the downbow.... “But do not, for all this, be a slave to your fingers. The music must come out of your soul, out of your soul.”
THEODOSIA would wake from the deep first sleep of the night and see the rectangles of the high windows turn to pale silver with the winter dawn. She would move in her bed, opening her eyes briefly upon the familiar furniture of the room, the long glass between the windows, the high dresser, the deep sofa beside the fireplace. Then she would settle to the lighter sleep of the morning, hearing the steps of early passers on the pavement of the street and hearing the click of the gate latch when Siver came to his work. The warmth of the bed would shut about her in a matutinal caress as she sank into light half-slumber, as her mind fared here and yon in speculations and dreams, in plans and visions. The joy of friends would give her a pleasant sense of well-being, and her own warmed youthful blood would drowse and drown in its own relaxed languors. Sometimes she would float between the earth and some void in a halfintoxication of a dream while her ears half-heard the steps on the street or a call—some boy driving his cow to pasture. Her speculating mind would run forward into the plans for the day, so many hours with the music, the fiddle, the harmony, the piano; or it would center briefly about some dress she was designing with the dressmaker or repairing for herself, and over this or through it would glide her floating senses as they drifted in the void supported by strong fingers on which she lay drooping, circled by strong arms. Siver’s knock at the door would dimly arouse her and make her know that she had half-dreamed some image, and his step on the floor as he walked toward the fireplace and bent over the grate to arrange the fire would emphasize the light quality of her consciousness. The sound of the falling kindling would be heavy and remote. Between the separate sounds the spaces of quiet would be
light with dreaming, with herself drowned in joy and myth, drooping in strong up-reaching fingers, Albert’s hands, but over her and above like the light of some final dawn, radiant but self-contained and entire, identical with light negligent laughter, would float some essence, some misty incandescence that merged with Conway and with her happiness.
When he had kindled a large fire of wood and coal, Siver would close the window and pour hot water from a pail into her pitcher on the wash-stand. He was nothing to her, Siver, but serving hands. He was but serving hands, unsensed, unrealized. He was a command given and accomplished. If he became momentarily real he was intently loathed and quickly transferred to serving hands again. The sound of the flowing water and the crockery would be as distinct and as meaningless as the other sounds of the morning, flat against the coming tide of the new day, unreal before her speculations about the dress or the fiddle-practice. Siver gone and the closed door having settled an hour of stillness upon the room, the earth would grow into the volume and substance of dream and lie finished and accomplished, apart and done.
THE farmers were discontented with the tobacco sales. The speculators were busy passing the crop from hand to hand, playing a game to outdo one another. Sometimes a farmer saw his crop selling for twice the sum he had been paid less than a week earlier. “Too many dead-heads function between the grower and the manufacturer,” Albert said. The tobacco wagons, piled high, were lined in every open space about the warehouses. A heavy odor of crude tobacco hung in the damp air.
At Catherine Lovell’s home there was a large double parlor with a hard smooth floor. Often the rugs were rolled up for dancing, and then two negroes sat in the hallway making the music, IDon’tKnow Why I Feel So Shy, or Dixie Dan, the rhythms brought down from Hill Street. Albert talked about the new association for the growers
as he waited between the dances, sitting along the wall of the dining-room on the red divan. The men would have to combine, he said. The market was all in a wreck. There would have to be such a pool as was never formed before, something solid. He spent his days now going about among the farmers, pledging them to the new measure, talking of it to hostile growers. He carried memoranda in his pocket snapped importantly together under a rubber band. The throb of the dance rhythms would wail from the outer hall. Somebody had given the players a smart drink and they set the true rhythms of Hill Street under the dancers’ feet, rhythms richly ripened with use. Theodosia and Conway trampled the rhythms under their light tread.
I likes a little loven now and then, When the loven one is you....
What was a rhythm more or less? their feet asked the smooth floor. “What’s this thing we’re a-dancen to?” Conway asked her. “Is it a two-step or a waltz or a barn dance, or what is it anyway?”
“Don’t you know really, on your honor?”
“I just get up and do what the music makes me. I never know what kind ’tis.”
Albert was a great bulk coming in at a door, coming nearer, taking his seat under the dim lamp when he sat in her parlor. His face was large and firm, sudden in its appraisals, but he was uncertain of her and of himself. She saw his uncertainty of her in his quick scrutiny of her when he spoke. The men would have to pool, he said. He had talked to twenty farmers and growers that day. He was dog tired. Some men were fools, unable to see their own good when it stood less than three inches away. She would turn to the fiddle, making herself remote.
SHE would pluck at his talkative music, making it utter its bland commonplace between flights of well-bowed musical comment, musical scorn. She would wrap each common saying into a sheaf bound lightly with shreds of scintillating clamor.
“Where’d you get that? How’d you know to do all that truck?” he asked.
“Imelda Montford wrote a diary and she left it in an old hamper. ‘I want to lern grek and laten. I will not be a idle fol. I will have what is in boks.’” She traced the words on the wall with her finger. “Roland built a bridge for a deposed king to ride on. William had red hair and owned nine thousand acres of Virginia land. Rufus bought a negro wench and three men from Captain Custer, and made a note of it in the back of a geography book. Thomas Montford bought a horse from Asa Fielding and left a note of that on the fly-leaf of an old grammar. Anne had a town named in her honor, Anneville. You know the place.”
“Anneville. I know. Gosh, yes.”
“Theodosia Montford took Luke Bell to husband and then the Bells got into the story.”
“Took. God’s sake! It’s my opinion she got took.”
“Gules two lions couchant argent....”
“What you a-comen to?”
“Gules with a fess and six crosslets gold....”
“What’s the joke?”
“Bendy of ten pieces, gold and azure....”
“What the ’ell?”
“The language of the Montfords. The speech of old Robert and his peers.”
“You’re too full of joy. I aim to take some of that joy out of you.”
“His glorious pals, you might say.”
