Contents

Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Motor Power 1Sensation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Reflex. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Chapter 1. Evaluation of Nerve Root Lesions Involving the Upper Extremity. . . . . . . . . 7Testing of Individual Nerve Roots C5 to T1 7

Neurologic Level C5. . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Neurologic Level C6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . .. 13Neurologic Level C7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 17Neurologic Level C8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . .. 21Neurologic Level Tl.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . .. 23

Clinical Application 28Herniated Cervical Discs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 28Cervical Neck Sprain versus Herniated Disc. . . . . . . . . . . . . . . . . . . .. 39Uncinate Processes and Osteoarthritis. . . . . . . . . . . . . . . . . . . . . . .. . .. 40General Tests for Reproducing and Relieving Symptoms of

Osteoarthritis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 42Nerve Root Avulsions .. .. .. ... ..... .. ... .... . .. .... .. . .. . ..... 42

Chapter 2. Evaluation of Nerve Root Lesions Involving the Trunk andLower Extremity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 45

Testing of Individual Nerve Roots T2 to S4 45Neurologic Levels T2-T12 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 45Neurologic Levels T12-L3 47Neurologic Levels L4 51Neurologic Levels L5 57Neurologic Levels S 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 61Neurologic Levels S2, S3, S4. . . . . . . . . . . . . . . . . . . . . . .. . . . . . . .. . .. 64

Clinical Application 66Herniated Lumbar Discs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 66Low Back Derangement versus Herniated Disc. . . . . . . . . . . . . . . . . .. 67Spondylolysis and Spondylolisthesis. . . . . . . . . . . . . . . . . . . . . . . . . . . .. 68Herpes Zoster. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 71Poliomyelitis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 72

Chapter 3. Cervical Cord Lesions: Tetraplegia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 77Evaluation of Individual Cord Levels-C3 to T1 77

Neurologic Level C3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 77Neurologic Level C4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 79

Chapter 3. Cervical Cord Lesions: Tetraplegia - (Continued)Neurologic Level C5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 80Neurologic Level C6 , 81Neurologic Level C7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 82Neurologic Level C8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 83Neurologic Level T1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 83

Upper Motor Neuron Reflex . . . . . .. 84Clinical Application 85

Fractures and Dislocations of the Cervical Spine .. . . . . . . . . . . . . . .. 85Herniated Cervical Discs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 91Tumors of the Cervical Spine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 91Tuberculosis of the Spine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 91Transverse Myelitis 91

Chapter 4. Spinal Cord Lesions Below Tl, Including the Cauda Equina . . . . . . . . . . . .. 93Paraplegia 93

Neurologic Level TI-T12. . . . . .. .. . .. . . .. . . . .. .. . .. . . . . . .. 93Neurologic Level L 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 94Neurologic Level L2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 94Neurologic Level L3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 94Neurologic Level L4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 94Neurologic Level L5 " '" '" .. 95Neurologic Level SI , '" " .. .. . . . . . .. . . . .. . . . .. 95

Upper Motor Neuron Reflexes 95Clinical Application 96

Further Evaluation of Spinal Cord Injuries. . . . . . . . . . . . . . . . . . . . . .. 96Herniated Thoracic Discs 100

Evaluation of Spinal Stability to Prevent Further NeurologicLevel Involvement. 101

Chapter 5. Meningomyelocele 107Determination of Level and Clinical Application 107

Neurologic Level Ll/L2 " " 109Neurologic Level L2/L3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 109Neurologic Level L3/L4 111Neurologic Level L4/L5 113Neurologic Level L5/S1 116Neurologic Level S 1/S2 118Neurologic Level S2/S3 118

Milestones of Development. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 118Unilateral Lesions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 119Hydrocephalus 119Involvement of the Upper Extremity 119Suggestions for Examination " 120

References 121Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 127

Introduction

The spinal cord is divided into segments.Nerve roots exit the spinal cord at each segcmental level, and are numbered in relation tothe l~vel from which they exit. There are eightcervIcal, twelve thoracic, five lumbar, and fivesacral nerves. The C5-Tl segments innervatethe upper extremity, and the T12-S4 segmentsthe lower extremity; these two sections of thecord have the greatest clinical significance.

Pathology affecting the spinal cord andnerve roots commonly produces symptomsand signs in the extremities according to thespecific neurologic levels involved. Thesel:vels can usually be diagnosed clinically,smce each level of injury has its own charac-teristic pattern of denervation.

The common denominator in injuries to ei-ther the cord or the nerve root lies in the seg-menta~ pattern of alteration of motor power,sensatIOn, and reflex in the extremities. Evalu-ation of the integrity of the neurologic levelsdepends upon a knowledge of the derma-tomes, myotomes, and reflexes. Different der-m~tomes (ar:as of sensation on the skin sup-plIed by a smgle spinal segment) and myo-tomes (groups of muscles innervated by asingle spinal segment) are affected dependingupon the level involved and upon whether thepathology involves the cord or the nerve rootsemanating from it. It is through a clinical eval-uation of motor power, sensation, and reflexthat the correct neurologic level of involve-ment can be established.

MOTOR POWER

The impulses that supply motor power aretransported in the spinal cord via the longtracts, and in particular via the corticospinaltracts. Interruption of the nerve root causesdenervation and paralysis of its myotome; in-terruption of the tract causes spastic paralysis(Fig. I-I). Pressure on the nerve root mayproduce a decrease in muscle strength that canbe evaluated best through the standards set bythe National Foundation of Infantile Paraly-sis, Inc., Committee on After-Effects, andadopted by the American and British Acade-mies of Orthopaedic Surgeons (Table 1-1).

In learning to grade a muscle, it is best toremember that a grade 3 muscle can move thejoint through a range of motion against grav-ity. Above grade 3 (grades 4 and 5), resistanceis added to the muscle test; below grade 3(grades 2, 1, and 0), gravity is eliminated as afactor.

Muscle testing should be repeated on a reg-ular basis to determine whether the level ofthe lesion has changed and created either fur-ther muscular paralysis or improvement. Re-petitive muscle testing against resistance helps~eter~ine whether the muscle fatigues easily,Implymg weakness and neurologic involve-ment.

Sensation of pain and temperature is carriedin the spinal cord via the lateral spinothalamic

CORTICO-SPINALTRACT

SPINO-THALAMICTRACT

FIG. I-I.tracts.

tract, whereas touch is carried in the ventralspinothalamic tract (Fig. 1-1). Pathology tothe cord or nerve root results in the loss oflight touch, followed by loss of sensation ofpain. During a recovery from nerve root in-jury, sensation of pain returns before lighttouch. The two sensations are tested separa-tely, light touch with a cotton swab, pain withpinpricks.

When testing for pain, use a pin in a gentlesticking motion. The pinpricks should followin succession, but not too rapidly. A pinwheel

is an excellent alternative method of evaluat-ing alterations in sensation, since two neuro-logic pinwheels can be used simultaneously,one on each side, to permit bilateral compari-son. Safety pins may also be used. The use ofneedles is not recommended since they havecutting surfaces and may injure the patient.Once an area of altered sensation is found, itcan be located more precisely by repeatedtesting from the area of diminished sensationto the area of normal sensation. Sensationtests depend largely upon subjective re-sponses; full cooperation of the patient is nec-essary.

After sensation is evaluated, the resultsshould be recorded on a dermatome diagramas normal, hyperesthetic (increased), hypes-thetic (decreased), dysesthetic (altered), or an-esthetic (absent).

The stretch reflex arc is composed of anorgan capable of responding to stretch (musclespindle), a peripheral nerve (axon), the spinalcord synapse, and muscle fibers (Fig. 1-2).

Complete range of motion againstgravity with full resistance

Complete range of motion againstgravity with some resistance

Complete range of motion againstgravity

Complete range of motion withgravity eliminated

Evidence of slight contractility.No JOInt motIon

No evidence of contractility

AFFERENTPERIPHERAL

NERVE

SPINAL CORDSYNAPSE

PATELLAR TENDONSTRETCH

Impulses descend from the brain along long(upper motor neuron) tracts to modulate thereflex. As a general rule, an interruption in thebasic reflex arc results in the loss of reflex,while pressures on the nerve root itself maydecrease its intensity (hyporeflexia). Interrup-tion of the upper motor neuron's regulatorycontrol over the reflex will ultimately cause itto become hyperactive (hyperreflexia).

Reflexes should be reported as normal, in-creased, or decreased, an evaluation which re-quires that one side be compared with theother. Bilateral comparison provides a direct,immediately accessible way to detect any al-teration in reflexes and is essential for an ac-curate diagnosis of pathology since the de-gree of reflex activity varies from person toperson.

The concept of determining neurologiclevels applies to the evaluation of spinal inju-ries, developmental anomalies, herniateddiscs, osteoarthritis, and pathologic processesof the cord itself. All these pathologic pro-cesses result in specific segmental distributionof neurologic signs in the extremities becauseof their direct effect on the spinal cord andnerve roots.

Note that the difference in findings betweencord or nerve root pathology as opposed to pe-ripheral nerve injuries is reflected in dif-ferences in the distribution of the neurologicfindings of motor power, sensation, and reflex.While each dermatome and myotome is inner-vated at a cord level and by a peripheral nerve,each has its own distinct pattern of innerva-tion.

1Evaluation of Nerve Root LesionsInvolving the Upper Extremity

Examination by neurologic level is basedupon the fact that the effects of pathology inthe cervical spine are frequently manifested inthe upper extremity (Fig. 1-1). Problemswhich affect the spinal cord itself or nerveroots emanating from the cord may surface inthe extremity as muscle weakness or abnor-mality, sensory diminution, and abnormalityof reflex; the distribution of neurologic find-ings depends upon the level involved. Thus, athorough neurologic testing of the extremityhelps determine any involvement of neuro-logic levels; it may also assist in the evaluationof an assortment of problems originating in thecervical cord or its nerve roots.

The following diagnostic tests demonstratethe relationship between neurologic problemsin the upper extremity and pathology involv-ing the cervical nerve roots. For each neuro-logic level of the cervical spine, motor power,reflexes, and areas of sensation in the upperextremity should be tested so that the level in-volved can be identified. We have begun indi-vidual nerve root testing with C5, the firstcontribution to the clinically important bra-chial plexus. Although C l-C4 are not includedin our tests because of the difficulty of testingthem, it is crucial to remember that the C4segment is the major innervation to the dia-phragm (via the phrenic nerve).

DISK--~-BODY (C-4)

TESTING OF INDIVIDUAL NERVE ROOTS:CS TO Tl

Neurologic Level C5Muscle Testing. The deltoid and the biceps

are the two most easily tested muscles withC5 innervation. The deltoid is almost a pureC5 muscle; the biceps is innervated by bothC5 and C6, and evaluation of its C5 innerva-tion may be slightly blurred by this overlap.

DELTOID: C5 (AXILLARY NERVE). The del-toid is actually a three-part muscle. The ante-rior deltoid flexes, the middle deltoid abducts,and the posterior deltoid extends the shoulder;

NEUROLOGIC LEVEL

CS

[ supraspinatusC5

FIG. 1-3B. Deltoid.Origin: Lateral third of clavicle, upper surface of

acromion, spine of scapula.I nsertion: Deltoid tuberosity of humerus.

FIG. 1-3C. Supraspinatus.Origin: Supraspinous fossa of scapula.I nsertion: Superior facet of greater tuberosity of

humerus, capsule of shoulder joint.

of the three motions, the deltoid acts mostpowerfully in abduction. Since the deltoiddoes not work alone in any motion, it may bedifficult to isolate it for evaluation. Therefore,note its relative strength in abduction, itsstrongest plane of motion (Fig. 1-2).

Primary shoulder abductors (Fig. 1-3).1. Deltoid (middle portion)

C5, C6 (Axillary nerve)2. Supraspinatus

C5, C6 (Suprascapular nerve)Secondary shoulder abductors

1. Deltoid (anterior and posterior por-tions)

2. Serratus anterior (by direct stabilizingaction on the scapula, since abduc-tion of the shoulder requires a stablescapula).

Stand behind the patient and stabilize theacromion. Slide your stabilizing hand slightlylaterally so that, while you stabilize the shoul-

Reflex TestingBICEPSREFLEX. The biceps reflex is pre-

dominantly an indicator of C5 neurologic in-tegrity; it also has a smaller C6 component.Note that, since the biceps has two majorlevels of innervation, the strength of the reflexneeds only to be slightly weaker than thestrength of the opposite side to indicate pa-thology.

To test the reflex of the biceps muscle, placethe patient's arm so that it rests comfortablyacross your forearm. Your hand should beunder the medial side of the elbow, acting assupport for the arm. Place your thumb on thebiceps tendon in the cubital fossa of the elbow(Fig. 1-8). To find the exact location of the bi-ceps tendon, have the patient flex his elbow

FIG. 1-8B. An easy way to remember that the bi-ceps reflex is innervated by C5 is to associate fivefingers with neurologic level C5.

slightly. The biceps tendon will stand outunder your thumb.

Instruct the patient to relax his extremitycompletely and to allow it to rest on your fore-arm, with his elbow flexed to approximately90°. With the narrow end of a reflex hammer,tap the nail of your thumb. The biceps shouldjerk slightly, a movement that you should beable to either see or feel. To remember the C5reflex level more easily, note that when the bi-ceps tendon is tapped, five fingers come up in auniversal gesture of disdain (Fig. 1-8).

Sensation TestingLATERALARM(AXILLARYNERVE).The C5

neurologic level supplies sensation to the lat-eral arm, from the summit of the shoulder tothe elbow. The purest patch of axillary nervesensation lies over the lateral portion of thedeltoid muscle. This localized sensory areawithin the C5 dermatome is useful for indicat-ing specific trauma to the axillary nerve aswell as general trauma to the C5 nerve root(Fig. 1-9).

Neurologic Level C6Muscle Testing. Neither the wrist extensor

group nor the biceps muscle has pure C6 in-nervation. The wrist extensor group is inner-vated partially by C6 and partially by C7; thebiceps has both C5 and C6 innervation (Fig.1-10).

WRIST EXTENSOR GROUP: C6 (RADIALNERVE)(Fig. 1-11)Radial extensors:

1. Extensor carpi radialis longus andbrevis

Radial Nerve, C6Ulnar Extensor:

1. Extensor carpi ulnaris, C7To test wrist extension, stabilize the fore-

arm with your palm on the dorsum of the wristand your fingers wrapped around it. Then in-struct the patient to extend his wrist. Whenthe wrist is in full extension, place the palm ofyour resisting hand over the dorsum of hishand and try to force the wrist out of the ex-tended position (Fig. 1-12). Normally, youwill be unable to move it. Test the oppositeside as a means for comparison. Note that theradial wrist extensors, which supply most ofthe power for extension, are innervated by C6,while the extensor carpi ulnaris is innervatedprimarily by C7. If C6 innervation is absentand C7 is present, the wrist will deviate to theulnar side during extension. On the otherhand, in a spinal cord injury where C6 is com-pletely spared and C7 is absent, radial devia-tion will occur.

BICEPS:C6 (MUSCULOCUTANEOUSNERVE).The biceps muscle, in addition to its C5 inner-vation, is partially innervated by C6. Test thebiceps by muscle testing flexion of the elbow.(For details, see page 11.)

Reflex TestingBRACHIORADIALISREFLEX. The brachio-

radialis is innervated by the radial nerve viathe C6 neurologic level. To test the reflex,support the patient's arm as you did in testingthe biceps reflex. Tap the tendon of the bra-

FIG. 1-9. The sensory distribution of the C5 neuro-logic level.

chioradialis at the distal end of the radius,using the flat edge of your reflex hammer; thetap should elicit a small radial jerk (Fig. 1-13).Test the opposite side, and compare results.The brachioradialis is the preferred reflex forindicating C6 neurologic level integrity.

BICEPSREFLEX.The biceps reflex may beused as an indicator of C6 neurologic integrityas well as of C5. However, because of thisdual innervation, the strength of its reflex needonly weaken slightly in comparison to the op-posite side to indicate neurologic problems.The biceps reflex is predominantly a C5 re-flex.

NEUROLOGIC LEVELC6BRACHIO-RADIALISTENDON

~

.•. ;,\\ / )

\'= ~

;~- j3-"c,

,{Xl.carp.rad.19. brC-6

ext.carp.uln.C-7

FIG. 1-11B. Extensor carpi ulnaris (left).Origin: From common extensor tendon from lat-

eral epicondyle of humerus, and from posterior bor-der of ulna.

Insertion: Medial side of base of 5th metacarpalbone.

FIG. 1-11C. Extensor carpi radialis longus (right).Origin: Lower third of lateral supracondylar

ridge of humerus, lateral intermuscular septum.Insertion: Dorsal surface of base of 2d metacar-

pal bone.

FIG. 1-11C. Extensor carpi radialis brevis (right).Origin: From common extensor tendon from lat-

eral epicondyle of humerus, radial collateral liga-ment of elbow joint, intermuscular septa.

Insertion: Dorsal surface of base of 3d metacar-pal bone.

16 Evaluation of Nerve Root Lesions Involving the Upper Extremity

FIG. 1-14. An easy way to remember the sensorydistribution of C6.

To test the biceps reflex, tap its tendon as itcrosses the elbow. (For details, see page 12.)

Sensation TestingLATERALFOREARM(MUSCULOCUTANEOUS

NERVE). C6 supplies sensation to the lateralforearm, the thumb, the index finger, and onehalf of the middle finger. To remember the C6sensory distribution more easily, form thenumber six with your thumb, index, and mid-dle fingers by pinching your thumb and indexfinger together while extending your middlefinger (Fig. 1-14).

Neurologic Level C7Muscle Testing. While the triceps, wrist flex-

ors, and finger extensors are partially inner-vated by C8, they are predominantly C7 mus-cles.

TRICEPS:C7 (RADIALNERVE) (Fig. 1-15).The triceps is the primary elbow extensor. Totest it, stabilize the patient's arm just proximalto the elbow and instruct him to extend his

arm from a flexed position. Before he reaches90°, begin to resist his motion until you havediscovered the maximum resistance he canovercome (Fig. 1-16). Your resistance shouldbe constant and firm, since a jerky, pushingtype of resistance cannot permit an accurateevaluation. Note that gravity is normally avaluable aid in elbow extension; if extensionseems very weak, you must account for it, aswell as for the weight of the arm. If extensionseems weaker than grade 3, test the triceps ina gravity-free plane. Triceps strength is impor-tant because it permits the patient to supporthimself on a cane or standard crutch (Fig. 1-17).

WRISTFLEXORGROUP: C7 (MEDIAN ANDULNAR NERVES)(Fig. 1-11)

1. Flexor carpi radialisMedian nerve, C7

2. Flexor carpi ulnarisUlnar nerve, C8

(Continued on page 20)

NEUROLOGIC LEVELC7

FIO. l-16A. Triceps bra-chii.

Origin: Long head frominfraglenoid tuberosity ofscapula, lateral head fromposterior and lateral sur-faces of humerus, medialhead from lower posteriorsurface of humerus.

Insertion: Upper poste-rior surface of olecranonand deep fascia offorearIh.

FIG. 1-17. Walking with a standardcrutch requires an active tricepsmuscle.

IFIG. 1-18A. Flexor carpi radialis (left).

Origin: Common flexor tendon from medial epi-condyle of humerus, fascia of forearm.

Insertion: Base of 2d and 3d metacarpal bones.

FIG. 1-18A. Flexor carpi ulnaris (right).Origin: Humeral head from common flexor ten-

don from medial epicondyle of humerus, ulnar headfrom olecranon and dorsal border of ulna.

Insertion: Pisiform, hamate, 5th metacarpalbones.

Finger Extension and Flexion

A FIG. 1-19 A. Finger extension - C7; finger flexion-C8.

The flexor carpi radialis (C7) is the more im-portant of these two muscles and providesmost of the power for wrist flexion. The flexorcarpi ulnaris, which is primarily innervated byC8, provides less power, but acts as an axisfor flexion. To understand this, note the ulnardirection that normal flexion takes.

To prepare for the wrist flexion test, instructthe patient to make a fist. The finger flexorscan, in some instances, act as wrist flexors;finger flexion removes them as factors duringthe test, since the muscles have contractedbefore the test begins. Stabilize the wrist; theninstruct the patient to flex his closed fist.When the wrist is in flexion, hold the patient'sfingers and try to pull the wrist out of its flexedposition (Fig. 1-18).

FIG. l-19B. Extensor digitorum.Origin: Lateral epicondyle of humerus by com-

mon extensor tendon, intermuscular septa.Insertion: Lateral and dorsal surface of phalan-

ges of medial four digits.

FINGER EXTENSORS:C7 (RADIAL NERVE)(Fig. 1-19)

1. Extensor digitorum communis2. Extensor indicis proprius3. Extensor digiti minimi

To test extension of the fingers, stabilize thewrist in the neutral position. Instruct the pa-tient to extend his metacarpophalangeal jointsand flex his interphalangeal joints at the sametime. Flexion of the interphalangeal jointsprevents the substitution of the intrinsic mus-cles of the hand for the long finger extensors.Place your hand on the dorsum of the ex-tended proximal phalanges and try to forcethem into flexion (Fig. 1-20).

Reflex Testing

TRICEPSREFLEX. The triceps reflex is in-nervated by the C7 component of the radialnerve.

To test the reflex of the triceps muscle, restthe patient's arm on your forearm; the positionis exactly the same as it was in the test for thebiceps reflex. Instruct the patient to relax hisarm completely. When you know that his armis relaxed (you can feel the lack of tension inthe triceps muscle), tap the triceps tendon as itcrosses the olecranon fossa (Fig. 1-21). Thetriceps tendon should jerk slightly, a move-

ment that you can either feel along your sup-porting forearm or see.

Sensation Testing

MIDDLE FINGER. C7 supplies sensation tothe middle finger. Since middle finger sensa-tion is also occasionally supplied by C6 andC8, there is no conclusive way to test C7 sen-sation.

Neurologic Level C8Muscle Test.FINGERFLEXORS(Fig. 1-19)

1. Flexor digitorum superficialisMedian nerve, C8

2. Flexor digitorum profundisMedian and ulnar nerves, C8

3. LumbricalsMedian and ulnar nerves, C8 (Tl)

The flexor digitorum profundus, whichflexes the distal interphalangeal joint, and thelumbricals, which flex the metacarpo-

NEUROLOGIC LEVEL

C8

tpNONE

(l

FIG. 1-23A. Flexor digitorum superficialis (left).Origin: Humeral head from common flexor tendon from me-

dial epicondyle of humerus, ulnar head from coronoid processof ulna, radial head from oblique line of radius.

I nsertion: Margins of palmar surface of middle phalanx ofmedial four digits.

Flexor digitorum profundus (right).Origin: Medial and anterior surface of ulna, interosseus

membrane, deep fascia of forearm.Insertion: Distal phalanges of medial four digits.

FIG. 1-23B. Lumbricales. (See opposite page)Origin: There are four lumbricales, all arising from tendons of

flexor digitorum profundus: 1st from radial side of tendon forindex finger, 2d from radial side of tendon for middle finger, 3dfrom adjacent sides of tendons for middle and ring fingers, 4thfrom adjacent sides of tendons for ring and little fingers.

Insertion: With tendons of extensor digitorum and interosseiinto bases of terminal phalanges of medial four digits.

phalangeal joint, usually receive innervationfrom the ulnar nerve on the ulnar side of thehand and from the median nerve on the radialside. If there is an injury to the C8 nerve root,the entire flexor digitorum profundus becomesweak, with secondary weakness in all fingerflexors. If, however, there is a peripheral in-jury to the ulnar nerve, weakness will existonly in the ring and little fingers. The flexordigitorum superficialis, which flexes the prox-imal interphalangeal joint, has only mediannerve innervation, and is affected by root in-jury to C8 and peripheral injuries to the me-dian nerve. (Fig. 1-22).

To test flexion of the fingers, instruct the pa-tient to flex his fingers at all three sets ofjoints: the metacarpophalangeal joints, theproximal interphalangeal joints, and the distalinterphalangeal joints. Then curl or lock yourfour fingers into his (Fig. 1-23). Try to pull hisfingers out of flexion. As you evaluate theresults of your test, note which joints fail tohold flexion against your pull. Normally, alljoints should remain flexed. To remember theC8 motor level more easily, note that themuscle test has four of your fingers in-tertwined with four of the patient's; the sumequals 8 (Fig. 1-24).

Sensation TestingMEDIAL FOREARM(MEDIAL ANTEBRACH-

IAL CUTANEOUSNERVE). C8 supplies sensa-tion to the ring and little fingers of the handand the distal half of the forearm. The ulnarside of the little finger is the purest area forsensation of the ulnar nerve (which is predom-inantly C8), and is the most efficient locationfor testing. Test the opposite side as a meansfor comparison, and grade your patient's sen-sation as normal, diminished (hypoesthesia),increased (hyperesthesia), or absent (anesthe-sia).

Neurologic Level TlTest Tl for its motor and sensory compo-

nents, since Tl, like C8, has no identifiablereflex associated with it (Fig. 1-25).

Muscle TestingFINGERABDUCTION(Fig. 1-26)

1. Dorsal interossei (D.A.B.) - (The ini-tials indicate that the Dorsal interosseiABduct.)

Ulnar nerve, T 1

FIG. 1-24. An easy way to remember that C8 in-nervates the finger flexors.

NEUROLOGIC

TI

INTEROSSEI

(V!~if;Finger Abductionand Adduction

2uln lumbricalsdorsol, palmar

InterosseiT-I

2. Abductor digiti quinti (fifth finger)Ulnar nerve, Tl

Note that all small muscles of the hand areinnervated by Tl. To test finger abduction, in-struct the patient to abduct his extended fin-gers away from the axial midline of the hand.Then pinch each pair of fingers to try to forcethem together: pinch the index to the middle,ring, and little fingers, the middle to the ringand little fingers, and the ring to the little fin-gers (Fig. 1-27). Observe any obvious weak-nesses between pairs and test the other handas a means of comparison.

Note that pushing the little finger to the ringfinger tests the abductor digiti quinti.

FINGERADDUCTION(Fig. 1-26)Primary Adductor

1. Palmar Interossei (P.A.D.)-(the InI-tials indicate that the Palmar interosseiADduct.)Ulnar nerve, C8, Tl

To test finger adduction, have the patienttry to keep his extended fingers together whileyou attempt to pull them apart. Test in pairs asfollows: the index and middle fingers, the mid-dle and ring fingers, and the ring and little fin-gers.

Finger adduction can also be checked if youplace a piece of paper between two of the pa-tient's extended fingers and pull it out from be-tween. The strength of his grasp should becompared to that of the opposite hand (Fig.1-28). To remember the Tl neurologic level

FIG. 1-26. Interossei dorsales (page 24).Origin: There are four dorsal interossei, each

arises by two heads from adjacent sides of metacar-pal bones.

Insertion: 1st into radial side of proximal phalanxof 2d digit, 2d into radial side of proximal phalanxof 3d digit, 3d into ulnar side of proximal phalanx of3d digit. 4th into ulnar side of proximal phalanx of4th digit.

more easily, pull a one-dollar bill from be-tween the extended fingers and associate theone dollar with neurologic level T 1.

Sensation TestingMEDIAL ARM (MEDIAL BRACHIAL-CUTA-

NEOUSNERVE). Tl supplies sensation to theupper half of the medial forearm and the me-dial portion of the arm.

SummaryThe following is a recommended scheme of

testing neurologic levels in the upper extrem-ity. In the neurologic examination of the upperextremity, it is practical to evaluate all motorpower first, then all reflexes, and finally sensa-tion. This method permits economy of effortand creates a minimum of disturbance for thepatient.

FIG. 1-29. Summary of muscle testing for the upperextremity.

FIG. 1-30. Summary of reflex testing for the upperextremity.

Motor power can be tested almost com-pletely in the wrist and hand with minimal mo-tion and effort for the examiner and patient.Wrist extension (C6), wrist flexion and fingerextension (C7), finger flexion (C8), and fingerabduction and adduction (T1) can all be per-formed in one smooth motion. Only C5 mustbe tested elsewhere, with the deltoid and bi-ceps muscles (Fig. 1-29).

Reflexes can all be obtained in a smooth pat-tern if the elbow and extremity are stabilizedin one position. It is then easy to move thereflex hammer to tap the appropriate tendon-biceps (C5), brachioradialis (C6), and triceps(C7) (Fig. 1-30).

Sensation can also be tested in a smooth pat-tern. Start proximally on the outer portion ofthe extremity and move down the extremity(C5, arm; C6, forearm), then across the fin-gers (C6, C7, C8). Finally, move up the innerborder of the extremity (C8, forearm; T1,arm), to the axilla (T2) (Fig. 1-31).

FIG. 1-31. Summary of sensation forthe upper extremity.

Neurologic Levels in UpperExtremity

MotorC5 - Shoulder AbductionC6 - Wrist extensionC7 - Wrist flexion and finger extensionC8 - Finger flexionTI-Finger abduction, adduction

SensationC5 - Lateral armC6 - Lateral forearm, thumb, and index fin-

gerC7 - Middle finger (variable)C8 - Medial forearm, ring, and small fingerTI-Medial armT2-Axilla

ReflexC5-BicepsC6 - BrachioradialisC7 - Triceps

CLINICAL APPLICATION OFNEUROLOGIC LEVELS

Herniated Cervical Discs

There are eight cervical nerves and onlyseven cervical vertebrae; thus, the first cer-vical nerve exits between the occiput and C 1,the sixth between C5 and C6, and the eighthbetween C7 and Tl (Fig. 1-32). A herniateddisc impinges upon the nerve root exitingabove the disk and passing through the nearbyneural foramen, and results in involvement ofone specific neurologic level. For example, aherniated disc between C5 and C6 impingesupon the C6 nerve root (Fig. 1-33).

There is slightly more motion between C5and C6 than between the other cervical ver-tebrae (except for between the specialized ar-ticulations of the occiput and C 1, and C 1 andC2) (Fig. 1-34, 1-35). Greater motioncauses a greater potential for breakdown, andthe incidence of herniated discs and osteoar-

r:

~

I ';;/ft;CERVICAL 4

NERVEROOTS(8)

l;

CERVICALVERTEBRAE

(7)

HERNIATEDDISC

thritis is greater at C5-C6 than at any of theother cervical disc spaces. The incidence ofherniation increases at C6-C7 as the patientgrows older; the reasons for this are not yetknown.

To involve the nerve root, the discs mustherniate posteriorly. They do so for two rea-sons: first, the annulus fibrosus is intact andstrong anteriorly and defective posteriorly;

FIG. 1-35. Specialized articulation between Cl andC2 allowing for 50 per cent of the rotation in thecervical spine.

second, the anterior longitudinal ligament isanatomically broader and stronger than thenarrower posterior longitudinal ligament.Since a disc usually herniates under pressure,it breaks through in the direction ofleast resis-tance, posteriorly. Because of the rhomboidalshape of the posterior longitudinal ligament,

FIG. 1-34. Specialized articulation between the oc-cipu t and C 1 allowing for 50 per cent of the flexionand extension in the cervical spine.

the disc also tends to herniate to one side orthe other (Fig. 1-36); it is less common tohave a midline herniation, since the disc wouldthen have to penetrate the strongest portion ofthe ligament.

Pain in one arm or the other is symptomaticof herniated cervical discs; the pain usually ra-

! .;'J

ANT ANNULUS FIBROSUS

HERNIATED DISCFIG. 1-36. The anatomic basis for posterior cervical disc herniation.

FIG. 1-37. Pattern of pain radiation with a midlineherniated cervical disc.

diates to the hand along the neurologic path-ways of the involved root, although, occasion-ally, the pain may be referred only as far as theshoulder. Coughing, sneezing, or strainingusually aggravates the pain and causes it to ra-diate throughout the involved neurologic dis-tribution in the extremity.

The symptoms and signs caused by a her-niated disc vary depending upon the locationof the herniation. If the herniation is lateral, asis most common, it may impinge directly uponthe nerve root, giving classical root-levelneurologic findings. However, if the disc her-niates in the midline, the symptoms may beevident in the leg and arm as well (Fig. 1-37).

FIG. 1-38. Pattern of pain radiation with a lateralprotrusion of a cervical disc.

If the disc protrudes but does not herniate,pain may be referred to the midline of the backin the area of the superior medial portions ofthe scapulae (Fig. 1-38). Lateral protrusionmay send pain along the spinous border of thescapula (most commonly to the superior me-dial angles), with radiation of pain down thearm, but usually without neurologic findings.

Occasionally, there may be inconsistentfindings of neurologic level involvement dur-ing the examination. Sometimes the brachialplexus, which usually includes the nerve rootsC5 to Tl, will begin a level higher (pre-fixed)or a level lower (post-fixed), causing varia-tions in the segmental innervation of the mus-cles; the findings will reflect this inconsistencyin the innervation of the upper extremity. It isalso possible that such major inconsistenciesare due to brachial plexus or peripheral nerveinjuries.

Specific Tests for Locating Herniated CervicalDiscs. To establish the exact neurologic level ofinvolvement secondary to a herniated disc,use the neurologic evaluation technique de-scribed earlier in the chapter. (Figs. 1-39 to1-43) (Text continues on page 37.)

NEUROLOGIC LEVEL

CS It;:4I~)

DISC LEVEL ~!

C4.C5 ~Jr:ta~~~

WRISTFLEXORSC7

FINGER

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FLEXORS, TI ~,,',j'h.,~j.~. 1.,,/,C8 ), lJ IJ:I' ~i~f

CNEUROL60GICLEVEL li>J

J~J7DISC LEVEL 7'C5,C6 ~: i1.~.

~(~ ,lff~d ~ :jo/I .....i."

U/( £;i;.

~@D

FINGER INTEROSSEI

FLEXORS. .TI ~. '1.' .'9.-....".•

;'

C8 ) ?(l~~

.'.'.. ~•.i:J.. '.~Ju.~w~UjJI "\

"\~

BICEPS BRACHIO-C5 RADIALIS

FIG. 1-40. A herniated disc between vertebrae C5 and C6 involves the C6 nerve root. This is the mostcommon level of disc herniation in the cervical spine.

C70G'CLEVEL y;41

DISC LEVEL J6,.'~)C6,C7 n /,

; )

P>G. 1-41 ... A herniated d. 0ISC between vertebrae C6 and .C7 Involves the C7 nerve root.

BICEPSC5,6~v.n~\Y

WRIST WRISTEXTENSORS FLEXORS

C6 [1 C71/ /;.~/

NEUROLOGIC LEVEL

C8 FINGER FINGEREXTENSORS1 FLEXORSC7 C

INTEROSSEI

~Qft.'~l.;~fltJlIl"'/J

DiSC LEVELC7, TI

BICEPS BRACHIO- TRICEPSC5 RADIALIS C 7

,C6 \

'~~\.i ) - 4) ~.. ,W" ,- /~

\~..'.~.' .~~5 ",...I,.. ".'.... '.. . . \. ~. 'fJ-=. I· .,'~t '.···~·d\'~' . / \.....-' :ce", "~• . t ".,

~---~ '---='----/

DISC LEVELTI, T2

DELTOID BICEPS WRIST WRISTC5 C56 EXTENSORS FLEXORS

~ ;\/' .if\ C~~ C7 ~.

'(_ \~ ...."...1 Af..·0 /:~C")~ ,Vr,1 / /INTEROSSE ITllllln~'L..A. ~i.I~.I'.;X~~(\III' "\

)~

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71FLEXORS

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Y

NEUROLOGIC LEVEL

TI

BICEPSC5

~

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FIG. 1-43. A herniated disc between vertebrae T1 and T2 involves the T1 nerve root. A herniated disc inthis area is unusual.

Table 1-1 summarizes the areas of neuro-logic level testing. In addition, it demonstratesthe clinical application of neurologic level test-ing to pathology in the cervical spine, espe-cially with regard to the evaluation of her-niated discs. Other ways of locating herniateddiscs are through:

1. The myelogram, which reveals the ab-normal protrusion of a herniated disc into thespinal cord, nerve root, or cauda equina at theinvolved level. It is the most accurate way todetect herniation, but should be reserved andused as a final test. (Fig. 1-44)

2. The electromyogram (EMG), which ac-curately measures motor potentials. Twoweeks after injury to a nerve, abnormal spon-taneous electrical discharges appear in theresting muscle (fibrillation potentials and posi-tive sharp waves). These are evidence of amuscle denervation, that can result from her-niated discs, nerve root avulsions, or cordlesions. (They can also occur in plexus and pe-ripheral nerve lesions.) It is important thatmuscles representing each neurologic level(myotome) be sampled for a complete evalua-tion (see Table I-Ion next page).

UncinateProcess

C5 C4-C5 Deltoid Biceps Lateral arm Fibrillation or Bulge in spinal C5Biceps Axillary nerve sharp waves in cord C4-C5

deltoid, biceps i"C6* C5-C6 Biceps Brachioradialis Lateral forearm Fibrillation or Bulge in spinal C6

Wrist extensors ~usculocutaneous sharp waves cord C5-C6nerve in biceps t

C7 C6-C7 Triceps Triceps ~iddle finger Fibrillation or Bulge in spinal C7Wrist flexors sharp waves cord C6-C7Finger extensors in triceps §

C8 C7-Tl Hand intrinsics Medial forearm Fibrillation or Bulge in spinalFinger flexors ~ed. Ant. Brach. sharp waves cord C7-TI

cutaneous nerve in intrinsichand muscles II

Tl Tl-T2 Hand intrinsics Medial arm Fibrillation or~ed. Brach. sharp waves incutaneous nerve hand muscles

* Most common level of herniationt Deltoid, rhomboid, supra and infraspinatus muscles:j: Extensor carpi radialis longus & brevis§ Triceps, flexor carpi radialis, extensor digitorum longusII Flexor digitorum muscles

General Test for Herniated Cervical Discs.The Valsalva test is a generalized test whichindicates only the presence of a herniated disc.The tests of each neurologic level are moreprecise and can pinpoint the exact level of in-volvement.

VALSALVA TEST. The Valsalva test in-creases the intrathecal pressure. If there is aspace-occupying lesion in the cervical canal,such as a herniated disc or a tumor, the patientwill develop pain in the cervical spine second-ary to the increased pressure. The pain mayradiate to the neurologic distribution of theupper extremity that corresponds to thepathologically involved neurologic level.

To perform the Valsalva test, have the pa-tient bear down as if he were moving hisbowels while he holds his breath. Then askhim ifhe feels any increase in pain either in thecervical spine or, by reflection, in the upperextremity (Fig. 1-45). The Valsalva test is asubjective test which requires that the patientanswer your questions appropriately; if he iseither unable or unwilling to answer, the test isof little value.

Cervical Neck Sprain Versus Herniated Disc

Patients frequently develop neck pain afterautomobile accidents that cause the cervicalspine to whip back and forth (whiplash) ortwist (Fig. 1-46A, B). The resulting injurymay stretch an individual nerve root, cause anerve root to impinge upon an osteoarthriticspur, or produce a herniated disc. Patientswith neurologic involvement complain of neckpain referred to the medial border of the scap-ula and radiating down the arm to varying

degrees, as well as of numbness and muscleweakness in the extremity. However, such aninjury may simply stretch the posterior or an-terior neck muscles, causing a similar neckpain with radiation to the shoulder and medialborder of the scapula.

Differentiation between generalized soft tis-sue injury without neurologic involvement andinjury with neurologic involvement can bemade by testing the integrity of the neurologiclevels innervating the upper extremities. Witheach patient visit, neurologic testing must berepeated, since an originally quiescent lesionmay later clinically manifest itself. Note thatthe converse is also true: patients who arehospitalized for treatment of neurologic prob-lems may show improved muscle strength, re-turn of a reflex, or return of normal sensationto the involved dermatome.

Many patients continue to complain of cer-vical pain six months to a year after injurywithout evidence of either neurologic or ob-

LATERALMA5S

/TRANSVERSE

FORAMEN

jective x-ray findings of pathology. The practi-tioner should have the confidence, despite pa-tient pressure, to continue conservative(nonoperative) therapy, knowing that the pa-tient may have a permanent soft tissue injurynot involving the anterior primary nerve rootsor the intervertebral cervical discs.

The Uncinate Processes and OsteoarthritisThe uncinate processes are two ridges of

bone which originate on the superior lateralsurface of the cervical vertebrae. They help tostabilize the individual vertebra, and partici-pate in the formation of the neural foramen(Fig. 1-47). Enlargements or osteoarthritis in-volving the uncinate process may encroachupon the neural foramen and directlycompress the exiting nerve root or limit theamount of room in which it can move (Fig. 1-48).

The neural foramen and the portion of theuncinate process encroaching upon it can be

UNCINATEPROCESS

SPINALNERVE

seen best on an oblique roentgenogram (Fig.1-49). Note that the nerve roots emerge at a45° angle from the cord and vertebral body,the same angle that exists between the neuralforamen and the vertebral body. An os-teophyte from the uncinate process has littleclinical significance unless it is accompaniedby symptoms. Clinical problems may ariseafter an automobile accident, when a patientwith a narrowed neural foramen may place ex-cessive strain on the nerve root lying in it

FIG. 1-48. Osteoarthritis of the uncinate process. because of the extreme extension/flexion ofthe head and neck and the subsequent reactive

FIG. 1-49. Narrowed neural foramen secondary toosteoarthritis of the uncinate process. C3-C4

edema of the nerve root. Note that the nar-rowed foramen frequently has the roentgeno-graphic appearance of a figure eight, a configu-ration which does not allow room for the post-traumatic swelling of the nerve and results inpain. Pain and neurologic findings are natu-rally found in the involved neural distributionin the upper extremity. For example, traumaaffecting the C6 nerve root may result in de-creased sensation to the lateral forearm, mus-cle weakness to the wrist extensors, and anabsent brachioradialis reflex (Fig. 1-35). It isalso possible, however, that the only symptomis referred pain to the superior medial angleand medial border of the scapula.

Where there is more motion, there is morechance of breakdown, and uncinate processenlargement secondary to osteoarthritis ismost often found at the C5-C6 bony level.

General Tests for Reproducing and RelievingSymptoms of Osteoarthritis

Distraction Test. The cervical spine distrac-tion test gives an indication of the effect ofneck traction in relieving pain. Distractionrelieves pain caused by the narrowing of theneural foramen (leading to nerve root com-pression) by widening the foramen, as well asby relieving pressure on the joint capsulesaround the facet joints; it may also help relievemuscle spasm by relaxing the contracted mus-cles involved.

To perform the cervical spine distractiontest, place the open palm of one hand underthe patient's chin and the other hand on his oc-ciput. Gradually lift (distract) his head so thatthe neck is relieved of its weight (Fig. 1-50).Determine whether he experiences any relieffrom pain.

Compression Test. The cervical spine com-pression test determines whether the patient'spain is increased when the cervical spine iscompressed. Pain caused by narrowing of theneural foramen, pressure on the facet joints, ormuscle spasm may be increased by compres-

sion. The compression test may also faithfullyreproduce pain referred down the upper ex-tremity from the cervical spine; in doing so, itmay assist in locating the neurologic level ofexisting pathology.

To perform the compression test, pressupon the top of the patient's head while he iseither sitting or lying down; discover whetherthere is any corresponding increase in pain ei-ther in the cervical spine or down the extrem-ity. Note the exact distribution of this pain andwhether it follows any previously describeddermatome (Fig. 1-51).

Nerve Root AvulsionsCervical nerve roots are frequently avulsed

from the cord during motorcycle accidents.When a rider is thrown from his cycle, hishead and neck are forced laterally and hisshoulder is depressed by the impact with theground, causing the cervical nerve roots tostretch and finally avulse (Fig. 1-52). The C5and C6 nerve roots are the roots most com-monly avulsed.

Physical examination shows the obviousresults: with the loss of the C5 root, there istotal motor paralysis among the C5 myotomeand sensory deficit along the C5 dermatome.The deltoid muscle is paralyzed, sensationalong the upper lateral portion of the arm ishypesthetic or anesthetic, and the biceps re-flex (C5-C6) is diminished or absent. Themyelogram shows a visable sacculation of dyeat the point of the avulsion, the origin of theC5 nerve root between the C4 and C5 ver-tebrae. Such a lesion is not amenable to surgi-cal repair. The injury is permanent; no recov-ery is to be expected.

Although C5 and C6 are the most com-monly avulsed roots, the C8 and Tl may alsobe avulsed. If the cyclist strikes the groundwith his shoulder hyperabducted, the lowestroots of the brachial plexus are usually theones injured, while the C5 and C6 nerve rootsremain intact.

FIG. 1-50. Distraction test (Hoppenfeld, S.: Physi-cal Examination of the Spine and Extremities, Ap-pleton -Cen tury -Crofts).

FIG. 1-51. Compression test (Hoppenfeld, S.:Physical Examination of the Spine and Extremities,Appleton -Century -Crofts).

C5FIG. 1-52. Avulsion of the C5 nerve root followinga motorcycle accident.

2 Evaluation of Nerve Root Lesions Involvingthe Trunk and Lower Extremity

Manifestations of pathology involving thespinal cord and cauda equina, such as her-niated discs, tumors, or avulsed nerve roots,are frequently found in the lower extremity.Understanding the clinical relationship be-tween various muscles, reflexes, and sensoryareas in the lower extremity and their neuro-logic levels (cord levels) is particularly helpfulin detecting and locating spinal problems withgreater accuracy and ease.

To make the relationship between the spineand the lower extremity clear, the neurologicexamination of the lumbar spine will be di-vided into tests of each neurologic level and itsdermatomes and myotomes. Thus, for eachneurologic level of the lower spinal cord, themuscles, reflexes, and sensory areas whichmost clearly receive innervation from it will betested.

TESTING OF INDIVIDUAL NERVE ROOTS,T2 TO S4

Neurologic Levels T2 to T12Muscle TestingINTERCOSTALS.The intercostal muscles are

segmentally innervated and are difficult toevaluate individually.

RECTUS ABDOMINUS.The rectus abdom-inus muscles are segmentally innervatedby the primary anterior divisions ofTS to T12(Ll), with the umbilicus the dividing point be-tween T10 and T11.

Beevor's sign (Fig. 2-1) tests the integrityof the segmental innervation of the rectus ab-dominus muscles. Ask the patient to do aquarter sit-up with his arms crossed on hischest. While he is doing this, observe theumbilicus. Normally, it should not move at allwhen the maneuver is performed. If, however,the umbilicus is drawn up or down or to oneside or the other, be alerted to possible asym-metrical involvement of the anterior ab-dominal muscles.

Sensory Testing. Sensory areas for eachnerve root are shown in Figure 4-1. The sen-sory area for T4 crosses the nipple line, T7 thexiphoid process, T10 the umbilicus, and T12the groin. There is sufficient overlap of theseareas for no anesthesia to exist if only onenerve root is involved. However, hypoesthe-sia is probably present.

Hip Flexion

iliopsoas(TI2)LI,2,3

FIG. 2-2B. Iliopsoas.Origin: Anterior surface of the bodies of alllum-

bar vertebrae and their transverse processes andcorresponding intervertebral discs. Upper twothirds of the iliac fossa.

Insertion: Lesser trochanter of femur.

Muscle Testing. There is no specific muscletest for each root. The muscles that are usu-ally tested are the iliopsoas (T12, Ll, L2, L3),the quadriceps (L2, L3, L4) and the adductorgroup (L2, L3, L4).

ILIOPSOAS:(BRANCHESFROM [T12], Ll,L2, L3) (Fig. 2-2). The iliopsoas muscle is themain flexor of the hip. To test it, instruct thepatient to sit on the edge of the examiningtable with his legs dangling. Stabilize his pelvisby placing your hand over his iliac crest andhave him actively raise his thigh off the table.Now place your other hand over the distalfemoral portion of his knee and ask him toraise his thigh further as you resist (Fig. 2-3).Determine the maximum resistance he canovercome. Then repeat the test for the op-posite iliopsoas muscle and compare muscle

strengths. Since the iliopsoas receives inner-vation from several levels, a muscle which isonly slightly weaker than its counterpart mayindicate neurologic problems.

In addition to possible neurologic pathol-ogy, the iliopsoas may become weak as aresult of an abscess within its substance; thepatient may then complain of pain duringmuscle testing. The muscle may also becomeweak as a result of knee or hip surgery.

QUADRICEPS:~L2, L3, L4 (FEMORALNERVE) (Fig. 2-4). To test the quadricepsfunctionally, instruct the patient to stand froma squatting position. Note carefully whetherhe stands straight, with his knees in full exten-sion, or whether he uses one leg more than theother. The arc of motion from flexion to exten-sion should be smooth. Occasionally, the pa-tient may only be able to extend the kneesmoothly until the last 10°, finishing the mo-

I\

)Ii'«ir'yl.~4c

quadricepsL2,3,4

FIG. 2-4B. Rectus femoris.Origin: Rectus femoris is a "two joint" muscle that has two

heads of origin. Straight head: from anterior inferior iliac spine.Reflected head: from groove just above brim of acetabulum.

Insertion: Upper border of patella, and then into the tibialtubercle via the infrapatellar tendon.

FIG. 2-4C.Vastus intermedius.

Origin: Upper two-thirds of anterior and lateral surface offemur.

Insertion: Upper border of the patella with the rectus femoristendon and then, via the infrapatellar tendon into tibial tubercle.

Vastus lateralis.Origin: Capsule of hip joint, intertrochanteric line, gluteal tu-

berosity, linea aspera.Insertion: Proximal and lateral border of patella, and into

tibial tubercle via the infrapatellar tendon.

FIG. 2-5. Extension lag. (Hoppenfeld, S.: PhysicalExamination of the Spine and Extremities, Ap-pleton-Century-Crofts).

Vastus MedialisOrigin: Lower half of intertrochanteric line, linea

aspera, medial supracondylar line, medial inter-muscular septum, tendon of adductor magnus.

Insertion: Medial border of patella and into tibialtubercle via the infrapatellar tendon.

tion haltingly and with great effort. This falter-ing in the last 10°of extension is called extensionlag; it occurs because the last 10°_15°of kneeextension requires at least 50 percent moremuscle power than the rest (according to Jac-queline Perry). Extension lag is frequentlyseen in association with quadriceps weakness.Sometimes, the patient may be unable to ex-tend his knee through the last 10° with eventhe greatest effort (Fig. 2-5).

To test the quadriceps manually, stabilizethe thigh by placing one hand just above theknee. Instruct the patient to extend his knee asyou offer resistance just above the ankle joint.Palpate the quadriceps during the test withyour stabilizing hand (Fig. 2-6). Note that thequadriceps weakness can also be due to areflex decrease in muscle strength followingknee surgery or to tears within the substanceof the muscle itself.

HIP ADDUCTORGROUP: L2, L3, L4 (OB-TURATORNERVE)(Fig. 2-7). Like the quadri-ceps, the hip adductors can be tested as a mas-sive grouping. Have the patient lie supine oron his side and instruct him to abduct his legs.Place your hand on the medial sides of bothknees and have him adduct his legs againstyour resistance (Fig. 2-8). Determine themaximum resistance he can overcome.

Reflexes. Although the patellar tendon reflexis supplied by L2, L3, and L4, it is predomi-nantly L4 and will be tested as such.

Sensory Testing. Nerves from LI, L2, andL3 provide sensation over the general area ofthe anterior thigh between the inguinal liga-ment and the knee. The L I dermatome is anoblique band on the upper anterior portion ofthe thigh, immediately below the inguinalliga-ment. The L3 dermatome is an oblique bandon the anterior thigh, immediately above thekneecap. Between these two bands, on the an-terior aspect of the midthigh, lies the L2 der-matome (Fig. 2-9).

Sensory testing, with its bands of individualdermatomes, is a more accurate way of eva-

Hip Adduction

adductor brevis

adductor longusadductor magnus

L2,3,4

FIG. 2-7B. Adductor brevis (center).Origin: Outer surface of inferior ramus of pubis.Insertion: Line extending from lesser trochanter

to linea aspera and upper part of linea aspera.

Adductor longus (left).Origin: Anterior surface of the pubis in the angle

between crest and pubic symphysis.Insertion: Linea asp era, middle half of medial lip.

Adductor magnus (right).Origin: Ischial tuberosity, inferior rami of is-

chium and pubis.Insertion: Line extending from greater tro-

chanter to linea aspera. The entire length of lineaaspera, medial supracondylar line, and adductortubercle of the femur.

luating neurologic levels T 12, L 1, L2, and L3than motor testing, which lacks individual rep-

resentative muscles. There are also no repre-sentative reflexes for these levels, making iteven more difficult to diagnose an exact neuro-logic level. Neurologic levels L4, L5, and S 1are represented by individual muscles, derma-tomes, and reflexes, and are easier to diag-nose.

Neurologic Level L4Muscle TestingTIBIALISANTERIOR:L4 (DEEP PERONEAL

NERVE)(Fig. 2-11). The tibialis anterior mus-cle is predominantly innervated by the L4 seg-mentallevel; italso receives L5 innervation. Totest the muscle in function, ask the patient towalk on his heels with his feet inverted. Thetendon of the tibialis anterior muscle becomesvisible as it crosses the anteromedial portionof the ankle joint and is quite prominent as itproceeds distally towards its insertion. Pa-

tients with weak tibialis anterior muscles areunable to perform this functional dorsiflexion-

inversion test; they may also exhibit "dropfoot," or steppage gait.

To test the tibialis anterior manually, in-struct the patient to sit on the edge of the ex-amining table. Support his lower leg, and placeyour thumb in a position that makes him dor-siflex and invert his foot to reach it. Try toforce the foot into plantar flexion and eversionby pushing against the head and shaft of thefirst metatarsal; palpate the tibialis anteriormuscle as you test it (Fig. 2-12).

Reflex TestingPATELLARTENDON REFLEX. The patellar

tendon reflex is a deep tendon reflex, mediatedthrough nerves emanating from the L2, L3,

NEUROLOGIC LEVEL

L4

tibialis anterior ]L4

~

COMM.PERONEA

N.

SCIATICN. ~ i,JI

TIBIAL N.

FIG. 2-11B. Tibialis anterior.Origin: Lateral condyle of tibia, upper two-thirds of the anterolateral surface

of tibia, interosseus membrane.Insertion: Medial and plantar surfaces of medial cuneiform bone, base of 1st

metatarsal bone.

and L4 nerve roots (predominantly from L4).For clinical application, the patellar tendonreflex should be considered an L4 reflex; how-ever, because it receives innervation from L2and L3 as well as from L4, the reflex will stillbe present, although significantly weakened,even if the L4 nerve root is completely sev-ered. The reflex is almost never totally absent.However, in primary muscle, nerve root, or an-terior horn cell disease, the reflex can be to-tally absent.

To test the patellar tendon reflex, ask thepatient to sit on the edge of the examiningtable with his legs dangling. (He may also siton a chair with one leg crossed over his kneeor, if he is in bed, with his knee supported in afew degrees of flexion) (Fig. 2-13). In thesepositions, the infrapatellar tendon is stretchedand primed. Palpate the soft tissue depres-sion on either side of the tendon in order tolocate it accurately, and attempt to elicitthe reflex by tapping the tendon at the levelof the knee joint with a short, smart wristaction. If the reflex is difficult to obtain, rein-force it by having the patient clasp his hands

(continued on p. 56)

FIG. 2-14. An easy way to remember that the pa-tellar tendon reflex is innervated by L4 is to associ-ate the four quadriceps muscles with the neurologiclevel L4.

NEUROLOGIC LEVEL

L5f

EXTENSORDIGITORUMLONGUS

~NONE

1/

Foot Dorsiflexion(Ankle Extension)

SUPPER. N

""~;~"j;", ).......~v~ PERN.

SCIATICN. ~ nIi

TIBIAL N

tibialis anteriorL4

ext. digitorum long.L5

ext. hallucis longL5

FIG. 2-16. L4, 5 - Foot dorsiflexion (ankle exten-sion).

FIG. 2-17 A. Extensor haUucis longus.Origin: Middle half of anterior surface of fibula,

adjacent interosseous membrane.Insertion: Dorsal surface of base of distal pha-

lanx of great toe.

FIG. 2-l7B. Extensor digitorum longus.Origin: Upper three-fourths of anterior surface

of fibula, interosseous membrane.Insertion: Dorsal surface of middle and distal

phalanges of lateral four toes.

FIG. 2-l7C. Extensor digitorum brevis.Origin: Forepart of upper and lateral surface of

calcaneus, sinus tarsi.Insertion: First tendon into dorsal surface of

base of proximal phalanx of great toe, remainingthree tendons into lateral sides of tendons of exten-sor digitorum longus.

AFIG. 2-l8A. Muscle test of the extensor hallucislongus muscle.

I·"

. ~'D'i) \:

I I.. 'I ... \'" I

~f ...../...l ....• 1)'

~FIG. 2-18C. An easy way to remember that the toeextensors are innervated by neurologic level L5.

gluteus mediusL5

Hip Abduction

FIG. 2-20A. Gluteus medius.Origin: Outer surface of ilium be-

tween iliac crest and posterior glu-teal line above to the anterior glu-teal line below, as well as the glutealaponeurosis.

Insertion: Lateral surface ofgreater trochanter.

and attempt to pull them apart as you tap thetendon. Repeat the procedure on the oppositeleg, and grade the reflex as normal, increased,decreased, or absent. To remember the neuro-logic level of the reflex, associate the fact thatfour muscles constitute the quadriceps musclewith the L4 of the patellar tendon reflex (Fig.2-14).

The reflex may be affected by problems

other than neurologic pathology. For example,if the quadriceps has been traumatized, if thepatient has undergone recent surgery to theknee, or if there is knee joint effusion, thereflex may be absent or diminished.

Sensory Testing. The L4 dermatome coversthe medial side of the leg and extends to themedial side of the foot. The knee joint is thedividing line between the L3 dermatome

above and the L4 dermatome below. On theleg, the sharp crest of the tibia is the dividingline between the L4 dermatome on the medialside and the L5 dermatome on the lateral side.

Neurologic Level LSMuscle Testing (Fig. 2-15, 2-16)

1. Extensor hallucis longus2. Extensor digitorum longus and brevis3. Gluteus medius

EXTENSORHALLUCISLONGUS:L5, (DEEPBRANCHOFTHE PERONEALNERVE).The ten-don of the extensor hallucis longus passes infront of the ankle joint lateral to the tibialis an-terior. Test it functionally by having the pa-tient walk on his heel, with his foot neither in-verted nor everted. The tendon should standout clearly on the way to its insertion at theproximal end of the distal phalanx of the greattoe. To test the extensor hallucis longus man-ually, have the patient sit on the edge of thetable. Support the foot with one hand aroundthe calcaneus and place your thumb in such a

position that he must dorsiflex his great toe toreach it. Oppose this dorsiflexion by placingyour thumb on the nail bed of the great toe andyour fingers on the ball of the foot; then pulldown on the toe (Fig. 2-17). If your thumbcrosses the interphalangeal joint, you will betesting the extensor hallucis brevis as well asthe longus; make certain that you apply resis-tance distal to the interphalangeal joint so thatyou are testing only the extensor hallucislongus. Note that a fracture of the great toe orother recent trauma will produce apparentmuscle weakness in the extensor hallucislongus.

EXTENSOR DIGITORUM LONGUS ANDBREVIS:L5, (DEEP PERONEALNERVE). Testthe extensor digitorum longus in function byinstructing the patient to walk on his heels, ashe did for the extensor hallucis longus. Thetendon of the extensor digitorum longusshould stand out on the dorsum of the foot,crossing in front of the ankle mortise and fan-ning out to insert by slips into the dorsal sur-

FIG. 2-21. L5 sensory derma-tome.

FIG. 2-20B. Muscle test for the gluteus mediusmuscle.

NEUROLOGIC LEVEL

51

PERONEUS ACHILLESLONGUS and TENDONBREVIS

'~.~~<'l~.~!}*\.'~/~r ..},*~'QJ

faces of the middle and distal phalanges of thelateral four toes.

For the manual test, the patient may remainseated on the edge of the table. Secure theankle with one hand around the calcaneusand place the thumb of your free hand in sucha position that he must extend his toes toreach it. Oppose this motion by pressing onthe dorsum of the toes and attempting to bendthem plantarward (Fig. 2-18). They shouldbe virtually unyielding.

GLUTEUS MEDIUS: L5, (SUPERIORGLU-TEALNERVE)(Fig. 2-19). To test the gluteusmedius, have the patient lie on his side. Stabi-lize his pelvis with one hand and instruct himto abduct his leg. Allow the leg to abduct fullybefore you resist by pushing against the lateralthigh at the level of the knee joint (Fig. 2-20).To prevent the muscle substitution that maytake place if the hip is allowed to flex, makesure it remains in a neutral position through-out the test.

Reflex Testing. There is no easily elicited

FIG. 2-24A. Peroneus longus.Origin: Head and proximal two-

thirds of lateral surface of fibula.Insertion: Lateral side of medial

cuneiform bone, base of I st metatarsalbone.

Peroneus brevis.Origin: Distal two-thirds of lateral

surface of fibula, adjacent intermuscu-lar septa.

Insertion: Styloid process of base of A5th metatarsal bone.

reflex supplied by the L5 neurologic level. Al-though the tibialis posterior muscle providesan L5 reflex, it is difficult to elicit routinely. If,after you have performed sensory and motortests, you are not certain of the integrity of theL5 level, you should try to elicit the tibialisposterior reflex by holding the forefoot in afew degrees of eversion and dorsiflexion, andby tapping the tendon of the tibialis posteriormuscle on the medial side of the foot justbefore it inserts into the navicular tuberosity.Normally, you should elicit a slight plantar in-version response.

Sensory Testing. The L5 dermatome coversthe lateral leg and dorsum of the foot. Thecrest of the tibia divides L5 from L4. To makethe distinction between L4 and L5 clearer,palpate the crest of the tibia from the knee dis-tally as it angles toward the medial malleolus.All that is lateral to the crest, including thedorsum of the foot, receives sensory innerva-tion from L5 (Fig. 2-21).

~.

i.\\", I

B/FIG. 2-24B. Muscle test for theperonei muscles.

Foot Plantarflexion(Ankle Flexion)

gastroc- soleusflex. dig long.flex. ha Liang.tibialis post

51

Neurologic Level 81Muscle Testing

1. Peroneus longus and brevis2. Gastrocnemius-soleus muscles3. Gluteus maximus

PERONEUSLONGUSAND BREVIS:S 1, (Su-PERFICIALPERONEAL NERVE) (Fig. 2-23).The peronei may be tested together in func-tion. Since they are evertors of the ankle andfoot, ask the patient to walk on the medial bor-ders of his feet. The peronei tendons shouldbecome prominent just before they turnaround the lateral malleolus, pass on eitherside of the peroneal tubercle (the brevisabove, the longus below), and run to their re-spective insertions.

To test the peronei muscles manually, havethe patient sit on the edge of the table. Securethe ankle by stabilizing the calcaneus andplace your other hand in a position that forceshim to plantarflex and evert his foot to reachit with his small toe. Oppose this plantarflex-ion and eversion by pushing against the headand shaft of the fifth metatarsal bone with thepalm of your hand (Fig. 2-24); avoid applyingpressure to the toes, since they may move.

~-----------FIG.2-26A. Gastrocnemius.

Origin: Medial head: from medial condyle andadjacent part of femur. Lateral head: from lateralcondyle and adjacent part of femur.

Insertion: Into posterior surface of calcaneus bycalcaneal tendon (Achilles tendon).

FIG.2-26B. Soleus.Origin: Posterior surface of head and upper third

of the fibula, popliteal and middle third of medialborder of tibia, tendinous arch between tibia andfibula.

Insertion: Into posterior surface calcaneus bycalcaneal tendon.

FIG. 2-26C. Muscle test for the gastrocnemius-soleus muscle group.

GASTROCNEMIUS-SOLEUSMUSCLES:S 1,S2,(TIBIAL NERVE) (Fig. 2-25). Since the gas-trocnemius-soleus group is far stronger thanthe combined muscles of your arm and fore-arm, it is difficult to detect small amounts ofexisting weakness; the group is thus a poorchoice for manual muscle testing and shouldbe observed in function. Ask the patient towalk on his toes; he will be unable to do so ifthere is gross muscle weakness. If the test isnormal, instruct him to jump up and down onthe balls of his feet, one at a time, forcing thecalf muscles to support almost two and a halftimes the body's weight. If he lands flat-footedor is otherwise incapable of performing thistest, there is weakness in the calf muscle (Fig.2-26). Obviously, elderly people or patientswith back pain cannot be expected to performthis portion of the functional test. Ask thesepatients to stand on one leg and rise up ontheir toes 5 times in succession. Inability tocomplete this test indicates calf muscle weak-ness.

GLUTEUS MAXIMUS:Sl, (INFERIORGLU-TEALNERVE)(Fig. 2-27). To test the gluteusmaximus functionally, have the patient standfrom a sitting position without using his hands.To test it more accurately for strength, askhim to lie prone on the examining table withhis hips flexed over the edge and his legsdangling. Have him bend his knee to relax thehamstring muscles so that they cannot assistthe gluteus maximus in hip extension. Placeyour forearm over his iliac crest to stabilizethe pelvis, leaving your hand free to palpatethe gluteus maximus muscle. Then ask him toextend his hip. Offer resistance to hip exten-sion by pushing down on the posterior aspectof his thigh just above the knee joint; as youperform the test, palpate the gluteus maximusmuscle for tone (Fig. 2-28).

Reflex TestingACHILLESTENDON REFLEX.The Achilles

tendon reflex is a deep tendon reflex, mediatedthrough the triceps surae. It is supplied pre-

FIG. 2-28A. Gluteus rnaxirnus.Origin: Posterior gluteal line

and lateral lip of iliac crest, pos-terior surface of sacrum and coc-cyx.

I nsertion: Iliotibial band of fas-cia lata, gluteal tuberosity offemur.

Hip Extension

gluteus moximus81

FIG. 2-28B. Muscle test for the gluteusmaximus.

dominantly by nerves emanating from the S 1cord level. If the S 1 root is cut, the Achillestendon reflex will be virtually absent.

To test the Achilles tendon reflex, ask thepatient to sit on the edge of an examining tablewith his legs dangling. Put the tendon intoslight stretch by gently dorsiflexing the foot.Place your thumb and fingers into the soft tis-sue depressions on either side to locate theAchilles tenson accurately, and strike it withthe flat end of a neurologic hammer to induce asudden, involuntary plantar flexion of the foot(Fig. 2-29). It may be helpful to reinforce thereflex by having the patient clasp his handsand try to pull them apart (or push them to-gether) just as the tendon is being struck. Toremember the SI reflex more easily, associate"AchilleS' 1 weak spot" with the reflex. (Fig.2-30).

\ \ \.

-~ y~ ~~tll,- ~-

ACHILLES 1 WEAK SPOT

FIG. 2-30. An easy way to remember that the ten-don of Achilles reflex is an S1 reflex.

There are various alternate methods of test-ing the Achilles tendon reflex, some of whichare described below. Choose the appropriatemethod, depending upon the condition of theparticular patient that you are examining.

If the patient is bedridden, cross one legover his opposite knee so that movement ofthe ankle joint is unhindered. Prime the ten-don by slightly dorsiflexing the foot with onehand on the ball of the foot and strike the ten-don. If he is lying prone in bed, ask him to flexhis knee to 90° and prime the tendon byslightly dorsiflexing his foot before performingthe test. If his ankle joint is swollen, or if it isprohibitively painful to tap the Achilles tendondirectly, have him lie prone with his ankleover the edge of the bed or examining table.Press the forepart of your fingers against theball of his foot to dorsiflex it and strike your

fingers with the neurologic hammer. A posi-tive reflex is present if the gastrocnemiusmuscle contracts and the foot plantar flexesslightly. You should be able to detect this mo-tion through your hand.

Sensory Testing. The S 1 dermatome coversthe lateral side and a portion of the plantar sur-face of the foot (Fig. 2-9).

Neurologic Levels 82, 83, 84Nerves emanating from the S2 and S3

neurologic levels supply the intrinsic musclesof the foot. Although there is no efficient wayto isolate these muscles for testing, you shouldinspect the toes for clawing, possibly causedby denervation of the intrinsics. S2, S3, andS4 are also the principal motor supply to thebladder, and neurologic problems which affectthe foot may affect it as well.

Reflex Testing. Note that there is no deepreflex supplied by S2, S3,and S4. There is,however, a superficial anal reflex. To test it,touch the perianal skin; the anal sphinctermuscle (S2, S3, S4) should contract (wink) inresponse.

Sensory Testing. The dermatomes around

the anus are arranged in three concentricrings, receiving innervation from S2 (outer-most ring), S3 (middle nng), and S4-S5 (inner-most ring) (Fig. 2-31).

SummaryThe following is a suggested clinical scheme

for most neurologic level testing in the lowerextremity. It is practical to evaluate all motorpower first, then all sensation, and finally allreflexes.

Most muscle testing of the involved lowerextremity can be performed with a minimumof effort and motion for examiner and patientif it is generally confined to the foot. Muscletest across the foot from the medial to the lat-eral side; the tibialis anterior on the medialside of the foot is innervated by L4, the exten-sor digitorum longus and brevis on the top ofthe foot by L5, and the peronei on the lateralside of the foot by S 1.

Sensation can also be tested in a smooth,continuous pattern across the dorsum of thefoot from medial to lateral. The medial borderof the foot receives innervation from L4, thetop of the foot from L5, and the lateral border

of the foot from S 1 (Fig. 2-32). It is practicalto test sensation in each extremity simultane-ously to obtain instant comparison. The skinover a muscle is usually innervated by thesame neurologic level as the muscle it covers.

Reflexes can be tested smoothly as well.With the patient seated, the appropriate ten-dons - infrapatellar tendon, L4; tendon ofAchilles, S 1- are easily tested.

NEUROLOGIC LEVELS IN LOWER

EXTREMITY

MotorL3 - Quadriceps (L2, L3, L4)L4 - Tibialis anteriorL5 - Toe extensorsSl-Peronei

FIG. 2-32. The sensory dermatomes (A) and(B) a practical method of testing sensationacross the dorsum of the foot.

SensationTl2-Lower abdomen just proximal to ingui-

nal ligamentLl- Upper thigh just distal to inguinalliga-

mentL2 - Mid thighL3 - Lower thighL4 - Medial leg - medial side of footL5 - Lateral leg - dorsum of footS 1- Lateral side of footS2 - Longitudinal strip, posterior thigh

ReflexL4 - PatellarL5 - Tibalis posterior (difficult to obtain)S 1- Achilles tendon

Root Disc Muscles Reflex Sensation E.M.G. Myelogram

L4 L3-L4 Tibialis Patellar Medial leg Fibrillation or Bulge in spinalanterior sharp waves in cord adjacent to

tibialis anterior L3-L4

L5 L4-L5 Extensor None Lateral leg Fibrillation or Bulge in spinalhallucis (Tibialis and dorsum sharp waves in cord adjacent tolongus posterior) of foot extensor hallucis disc L4-L5

longust

Sl L5-S1 * Peroneus Achilles Lateral foot Fibrillation or Bulge in spinallongus tendon sharp waves in cord adjacent to& brevis peroneus disc L5-S1

longus& brevist

* Most common level of herniationt Extensor digitorum longus and brevis, medial hamstring, gluteus medius muscles:j: Flexor hallucis longus, gastrocnemius, lateral hamstring, gluteus maximus muscles

CLINICAL APPLICATION OFNEUROLOGIC LEVELS

Herniated Lumbar Discs

Lumbar discs, like cervical discs, usuallyherniate posteriorly rather than anteriorly andto one side rather than in the midline; the ana-tomic reasons for each type of herniation arethe same (see page 28), and the disc usuallyimpinges only upon one of the two nerve rootsat each level (Fig. 2-33). The patient usuallycomplains of pain radiating into one leg or theother, and rarely of pain radiating into bothlegs at the same time.

Note that there is a special relationship be-tween the nerve roots of the cauda equina andthe disc space. Before it exits through theneural foramen, the nerve root turns at ap-proximately a 45° angle around the pedicle ofits vertebra. Because the pedicle is situated inthe upper third of the vertebral body, thenerve root, which is relatively tethered to it,never crosses the disc space below and thus is

usually not involved in any herniations of thedisc within that space (Fig. 2-34). A nerveroot is commonly involved only in herniationsof the disc located above its point of exit. Forexample, the L5 nerve root crosses the discspace between L4 and L5, then turns aroundthe pedicle of L5, and leaves the spinal canalvia the neural foramen before it reaches theL5-S 1 disc space. It may be affected by an L4-L5 herniation, but not by one between L5 andS 1.Thus, a patient whose symptoms are mani-fested along the L5 distribution has a poten-tial herniation in the disc space above the L5vertebra.

The L4- L5 and L5-S 1 articulations have thegreatest motion in the lumbar spine. Greatermotion causes an increased potential forbreakdown, and the incidence of herniateddiscs is greater at L4- L5 and L5-S 1 than atany other lumbar disc space in the entirespine.

Table 2-1 delineates the applicable tests forthe most clinically relevant neurologic levels.

HERNIATED DISC

FIG. 2-33. The anatomic basis for posterior lumbardisc herniation.

It applies most critically to problems of her-niated discs (Fig. 2-35, 2-36, 2-37, 2-38).

Although this table reflects precise neuro-logic levels, the clinical picture may not be asclear. The reasons for discrepancies are nu-merous. For example, a nerve root may occa-sionally carry elements of adjacent nerveroots. Thus, the L4 root may contain compo-nents of L3 or L5. In addition, a single discherniation may involve two nerve roots. Thisapplies particularly to the L4-L5 disc, whichmay compress not only L5 root but also the S Iroot, particularly if the herniation is in themidline. Disc herniation occasionally occursat more than one level, giving an atypicalneurologic pattern.

SI

\),/

FIG. 2-34. The anatomic basis for nerveroot impingement by a herniated disc.

Low Back Derangement versus Herniated DiscPatients frequently develop "low back"

pain after lifting heavy objects or falling, orafter a violent automobile accident whichthrows or twists them around the interior ofthe car. These patients complain of back pain(point tenderness or pain across the lowerlumbar spine) with radiation to varying de-grees around the posterior superior iliacspines and down the back of the leg.

Complaints of a generalized backache orlow back derangement without neurologic in-volvement can be differentiated from thosewith neurologic involvement by testing theneurologic levels innervating the lower ex-tremity. The tests should be repeated witheach visit, since a loss offunction not apparentin the initial examination, a further loss ofmuscle strength, reflex, or sensation in the in-volved neurologic level, or an improvementfrom the initial findings (as a result, perhaps,of treatment) may occur.

Unless there is evidence either of an alter-ation in reflex, sensation, or motor power or of

NEUROLOGIC LEVEL

L4DISC LEVELL3, L4

@

TIBIALISANTERIORL4

PERONEUSLON.GUSSI ,

'- II

positive findings on roentgenogram or elec-tromyogram, conservative therapy shouldcontinue despite patient pressure for a changein treatment.

Although neurologic involvement of a her-niated disc is most often manifested by the al-teration of only one or two signs, there shouldbe enough information to help pinpoint the in-volved neurologic level. Certainly the elec-tromyogram and myelogram can be used asfurther diagnostic tools. But your clinicaljudg-

ment, based on the physical examination ofthe patient, will most often allow you to makethe proper neurologic diagnosis and prescribethe correct treatment.

Spondylolysis and Spondylolysthesis

Spondylolysis refers to the lytic line thatcrosses the pars interarticularis, the area be-tween the superior and the inferior articulatingprocesses, or, more precisely, the point atwhich the inferior articulating process ap-

NEUROLOGIC LEVEL

L5 TIBIALISANTERIORL4

DISC LEVELL4,L5

FIG. 2-36. A herniated disc between vertebrae L4 and L5 involves the L5 nerve root. This is the secondmost common level of disc herniation in the lumbar spine.

proaches the pedicle. As a result of this pa-thology, the involved vertebra may slip for-ward on the vertebra immediately inferior toit. This forward slippage is called spon-dylolysthesis. Although the etiology of thedefect of the pars interarticularis is still un-known, it is commonly believed to be theresult of a fracture due to repeated stress.Because of the frequency of L5-S 1 spon-

dylolysthesis with involvement of L5-S 1nerve roots, the hamstrings, supplied mediallyby L5 and laterally by S 1, may well go intospasm. Both sensation and reflex usually re-main normal, unless there is an associated her-niated disc. Occasionally, spondylolysthesismay occur even with an intact pars interar-ticularis in patients with degenerative arthritis.However this is very unusual.

NEUROLOGIC LEVEL

51DISC LEVELL5, SI

FIG. 2-37. A herniated disc between vertebrae L5 and Sl involves the Sl nerve root. This is the mostcommon level of disc herniation in the lumbar spine.

The degree of forward slippage is measuredclinically by the relationship of the superiorvertebra to the inferior vertebra (the superiorvertebra slips forward). A slip of up to 25percent is termed a first-degree slip, 25 to 50percent a second-degree slip, and 50 to 75 per-cent a third-degree slip. Any greater slippageis termed a fourth-degree slip. The vertebramost commonly involved in spondylolysis andspondylolysthesis is the L5 vertebra. The sec-ond most common is L4.

The degree of pain that the patient experi-ences is not necessarily related to the degreeof slippage, so that a patient with a first-degreeslip may feel greater pain than a patient with afourth-degree slip, who may, in fact, feel nopain at all.

An increase of symptoms in patients withspondylolysis or spondylolysthesis can oftenbe a result of an associated herniated lumbardisc. The incidence of a herniated disc isgreater in patients with spondylolysthesis than

in the general population. The disc herniationusually occurs one level above the bony pa-thology. For example, if there is a bony defectat L5, the disc between L4 and L5 is the onemost likely to herniate. The involvement ofthe L5 nerve root may produce associatedneurologic findings, such as positive straightleg raising, toe extensor weakness, and dimi-nution of sensation on the dorsum of the foot.Although such involvement usually stemsfrom an associated herniation, the nerve rootmay also become impinged directly from aspondylolysthesis.

Spondylolysis and spondylolysthesis are

frequent causes of teenage backache; the pa-tient usually complains of back pain, particu-larly after sports activities.

Note that spondylolysis has a characteristiclook on a roentgenogram (Fig. 2-39, 2-40).

Herpes ZosterHerpes zoster (shingles) is a viral disease

which usually involves a single, unilateral der-matome. Thoracic roots are most commonlyinvolved. Pain frequently precedes the ap-pearance of the skin lesion and follows the dis-tribution of the nerve root, without crossingthe midline. The level involved can be located

ASCENDINGPROCESSES

/

FIG. 2-39. Schematic drawing of an oblique roentgenogram of the lum-bar spine, showing the characteristic "scotty dog" look of its posteriorelements. Note that the defect in the pars interarticularis appears to bea collar around the dog's neck.

through appropriate sensory testing and evalu-ation of the level of the skin lesion.

PoliomyelitisPoliomyelitis is an acute viral infectious dis-

ease which may inflict temporary or perma-nent destructive changes in motor function. Itinvolves the destruction of the anterior horpcells of the spinal cord. Poliomyelitis usuallyattacks younger patients, causing motor paral-

ysis and atrophy. It does not affect sensation,and reflexes, although diminished, are usuallypresent, because the reflex arcs remain intactunless all the anterior horn cells are destroyed(Fig. 2-41).

Although its lesion lies in the cord, theclinical appearance of poliomyelitis may besimilar to that of a nerve root lesion, since thevirus destroys the cells of the nerve root. Atleast 50 percent of the anterior horn cells inthe levels innervating a particular muscle must

be involved before there is any clinical evi-dence of muscle weakness (according to W. J.W. Sharrard). Poliomyelitis attacks the ante-rior horn cells segmentally - it does not simplyinvolve all levels in an area-and it may skiplevels, leaving them free of pathology. Thisleads to a smaller degree of involvement formuscles which are innervated by severallayers. For example, the quadriceps muscle,which is innervated by L2, L3, and L4, doesnot experience any significant weaknessunless 50 percent of the anterior horn cells ofall three levels are involved. Conversely, thetibialis anterior muscle, which is innervatedmainly by L4, is affected by the involvementof 50 percent of the anterior horn cells of thatlevel, causing the relatively common problemof foot drop. If the anterior horn cells of thefifth lumbar level are involved, weakness ofthe gluteus medius muscle, the medial ham-strings, and the toe extensors may occur. Ifthe anterior horn cells of the first sacral levelare involved, there may be weakening of thegluteus maximus muscle, the lateral ham-string, and the peronei and calf muscles.

Through vaccination, poliomyelitis hasbeen practically eliminated as a serious prob-lem.

GREATER THAN50% LOSS OFANTERIOR HORN CELLS

VENTRALFIG. 2-41. Anterior horn cell loss leading to clini-cal muscle weakness.

MUSCLE NEUROLOGIC LEVEL * NERVE

Hip flexors .. " L-l,2,3Hip adductors L-2,3,4 Obturator nerveQuadriceps. '" L-2,3,4 Femoral nerveTib. anterior L-4,5 Deep peroneal nerveTib. posterior L-4,5 Post. tibial nerveGlut. medius L-4,2 S-l Superior gluteal nerveMed. hamstrings L-4,2 S-l Sciatic nerve, tibial portionEx. Dig. longus L-2 S-l Deep peroneal nerveEx. Hal. longus L-2 S-l Deep peroneal nervePeronei L-5 S-1,2 Superficial peroneal nerveCalf L-5 S-1,2 Tibial nerveLat. hamstring L-5 S-1,2 Sciatic nerve, tibial portionGlut. maximus L-5 S-1,2 Inferior gluteal nerveFlex. Hal. Long S-1,2 Tibial nerveFlex. Dig. Long S-1,2 Tibial nerveToe intrinsics S-2,3 Lat. and Med. plantar nervesPerineum S-2,3,4

* According to Sharrard_ Predominant neurologic level

Spinal Cord Lesions byNeurologic Level

The acute injuries leading to tetraplegia andparaplegia present great problems in bothearly diagnosis of the levels of neural involve-ment and prognostication of future function.In today's society, where potentially debilitat-ing occurrences, including war, auto and in-dustrial accidents, and contact sports, arecommon, there is a need for a concise systemof early neurologic examination. Traumaticpathology of any kind that affects the spineand spinal cord must be diagnosed immedi-ately and must be accurately and promptlytreated. The key to management of spinal in-juries is immediate protection of the spinalcord, even if an immediate examination is notperformed. Without immediate protection, in-

complete lesions of the cord can be convertedto complete lesions, and partially contusednerve roots may be totally lost.

Spinal injuries may occur at any level. Eachlevel at which an injury can occur gives spe-cial problems: acute injuries to the cervicalspine may result in death or tetraplegia; inju-ries to the thoracic spine usually lead to spas-tic paraplegia; and injuries to the lumbar spine(cauda equina injuries) can result in varyingdegrees of flaccid lower extremity paralysis.The following discussion deals with thesethree zones and with methods of examinationthat help to establish a precise level of neuralinvolvement and still are economical of timeand effort.

3 Cervical Cord Lesions: Tetraplegia

Tetraplegia, or quadriplegia as it is morecommonly known, means paralysis involvingall four extremities. The lesion which causessuch paralysis occurs in the cervical spine.While it results in complete paralysis of thelower extremities, it may partially or whollyaffect the upper extremities, depending uponthe neurologic level involved.

In an analysis of tetraplegia, establishmentof the level of neural involvement and evalua-tion of its degree (whether the cord lesion iscomplete or incomplete) are of primary con-cern. Both these factors must be known beforethere can be any attempt at prediction of re-covery of neurologic function or before any ef-fective program of therapeutic treatment andrehabilitation can be planned. The more rapidthe rate of return of spinal cord function, thegreater the amount of recovery and, con-versely, the slower the rate of return, the smal-ler the amount of recovery. This rule of thumbmakes it easier to estimate the future possibil-ity of both ambulation and bladder and bowelfunction. Since, at the beginning, the patientmay be in a state of spinal shock (diaschisis),from which some neural recovery may occur,a thorough neurologic examination, repeatedevery two to four hours for the first 48 hours,may begin to provide some answers about thepotential for recovery. Each examination mustinclude muscle testing, sensory testing, and

reflex testing to permit a complete evaluationof the possibility of cord return.

EVALUATION OF INDIVIDUAL CORDLEVELS: C3 TO T1

If the cervical cord is completely tran-sected, complete paralysis of the lower ex-tremities occurs, but the degree of paralysis ofthe upper extremities depends on the neuro-logic level involved. Although some cervicalcord lesions are, in reality, incomplete or par-tial (so that some function remains below thelevel of the lesion) we shall discuss the signsas if each cord lesion is complete, since thereal issue is to determine the level of injury.

Spinal shock and associated muscle flac-cidity usually pass between 24 hours and threemonths after trauma. Spasticity and clonus setin and gradually increase in intensity. Thedeep tendon reflexes become exaggerated andpathologic reflexes appear.

Neurologic Level C3 (C3 Intact)A neurologic level of C3 means that the

third cervical root is intact, while the fourth isnot. Neurologic level C3 corresponds to ver-tebrallevel C3-4 (Figs. 3-1, 3-2).

Motor Function. There is no motor functionin the upper extremities; the patient is com-pletely tetraplegic. Muscles are flaccid as a

NEUROLOGIC LEVEL

C2BONY LEVELC2,C3

MOTORDELTOID BICEPS WRIST

~

5 .,,", "C5,6, ,'. EXTE.NS...ORS

f'" ~~6

, ~? - , _'<d.

\" ~ "): ":. . /; ~, ' / ~, - ,1$

~~ \ ~.' ~ /

WRISTFLEXORSC7

FINGER

~

RESPIRATION

~~_.~~.,.~:

,

PERMANENTRESPIRATORYSUPPORT

result of denervation and spinal shock. Afterspinal shock has worn off, the muscles willdemonstrate varying degrees of spastic re-sponse. Since the diaphragm is suppliedlargely by C4, the patient is unable to breatheindependently, and will die without artificialrespiratory assistance. Sometimes, in what atfirst appears to be a C3 level, C4 later recov-

ers, with a return of diaphragmatic function.Sensation. There is no sensation in the upper

extremities or below a line three inches abovethe nipple on the anterior chest wall.

Reflexes. In the presence of spinal shock, alldeep tendon reflexes are absent. When spinalshock has worn off, they will become brisk toexaggerated and pathologic reflexes may beevident.

NEUROLOGIC LEVEL

C3BONY LEVELC3,C4

DELTOID SICEPS WRIST

~

5.. ... .... ..C.5,6. . E..XTENS.ORS'./~~6 ...'- ~ '" I

i "'. . / ~

-=/~\ " '1

WRISTFLEXORSC7

f FINGERFLEXORS1)1

SICEPS SRACHIO- TRICEPS

~~~

and shrug his shoulder. But the lack of func-tioning intercostal and abdominal muscleskeeps the patient's respiratory reserve low,although probably adequate for the reducedlevel of function.

Sensation is present on the upper anteriorchest wall, but not in the upper extremities.

Reflexes. Initially, all deep tendon reflexes

The fourth cervical cord segment remainsintact. The lesion lies between the 4th and 5thcervical vertebrae (Fig. 3-3).

Motor Function. The muscles of the upperextremity are nonfunctional. Since C4 is in-tact, the patient can breathe independently

BICEPS

~~;:~

are absent, but the passing of spinal shockmay bring changes.

Neurologic Level C5 (C5 Intact)A lesion at this level leaves C5 intact. Since

this is the first cord level to contribute to theformation of the brachial plexus, the upper ex-tremity will have some function (Fig. 3-4).

Motor Function. The deltoid muscle and aportion of biceps muscle are functioning. Thepatient is able to perform shoulder abduction,flexion, and extension, as well as some elbow

flexion. However, all these motions are weak-ened since the muscles governing these move-ments usually have contributions from the C6nerve root. The patient cannot propel a wheel-chair by himself and his respiratory reserve islow.

Sensation is normal over the upper portionof the anterior chest and the lateral aspect ofthe arm from the shoulder to the elbow crease.

Reflexes. Since the biceps reflex is primarilymediated through C5, it may be normal orslightly decreased. As spinal shock wears off

BICEPSC5,6

/~V··~··'····.."~..""... \" . ), I

\> .~

NEUROLOGIC LEVELCS FINGER

~

6L8E.X.ORS]

/)'

!ii0

BONY LEVELC5,C6

BICEPSC5

BRACHIO-RADIALISC6

TRICEPSC7

~

"",.... "" ..\.,~\ /d'4

and elements of C6 return, the reflex maybecome brisk.

carpi ulnaris - C7 - is still involved). The pa-tient has almost full function of the shoulder,full flexion of the elbow, full supination andpartial pronation of the forearm, and partialextension of the wrist. The strength of wristextension is normal, since power for extensionis predominantly supplied by the extensorcarpi radialis longus and brevis.

Respiratory reserve is still low. The patientis confined to a wheelchair, which he canpropel over smooth, level surfaces.

Sensation. The lateral side of the entire

Neurologic Level C6 (C6 Intact)Involvement is at skeletal level C6- 7 (Fig.

3-5).Motor Function. Because both C5 and C6

are intact, the biceps and the rotator cuffmuscles function. The most distal functionalmuscle group is the wrist extensor group; theextensor carpi radialis longus and brevis (C6)are both innervated (although the extensor

NEUROLOGIC LEVELC6BONY LEVELC6,C7

upper extremity, as well as the thumb, theindex, and half of the middle finger, have anormal sensory supply.

Reflexes. Both the biceps and the brachio-radialis reflexes are normal.

Neurologic Level C7 (C7 Intact)Involvement is at vertebral level C7 -T 1

(Fig. 3-6).Motor Function. With the C7 nerve root in-

BICEPS

J"~~\.",w~//'V

WRISTEXTENSORS

) ..t:jr/WRISTFLEXORSC7

SENSATION

~~,r~.!:~

tact, the triceps, the wrist flexors, and the longfinger extensors are functional. The patientcan hold objects, but his grasp is extremelyweak. Although he is still confined to a wheel-chair, the patient may begin to attempt parallelbar and brace ambulation for general exercise.

Sensation. C7 has little pure sensory repre-sentation in the upper extremity. No precisezone for C7 sensation has been mapped.

Reflexes. The biceps (C5), brachioradialis(C6), and triceps (C7) reflexes are normal.

BICEPSC5,6/ M~)

WRISTEXTENSORS:~~r/;

FINGER

EXT.EN·rS..ORSC7 A

/J'~

BRACHIO-RADIALISC6

TRICEPSC7

I .. J. \ ) / ~

~.'.V7-\,':1

~.~A \

Neurologic Level C8 (C8 Intact)Involvement is at skeletal level TI-T2 (Fig.

3-7).Motor Function. The upper extremity is nor-

mal, except for the intrinsics of the hand.Thus, all upper extremity motions except fin-ger abduction, finger adduction, and the pinchmechanism of the thumb, index, and middlefingers are intact. Grasp is difficult, since thehand is intrinsic minus or clawed.

Sensation. The lateral aspect of the upperextremity and the entire hand have normal

sensory awareness. Sensation on the medialside of the forearm is normal to several inchesbelow the elbow.

Reflexes. All upper extremity reflexes are in-tact.Neurologic Level Tl (Tl Intact)

Involvement occurs at skeletal level T2-T3.Motor Function. Involvement at neurologic

level TI results in paraplegia. The upper ex-tremity is fully functional. The brachialplexus' neurologic supply (C5-TI) is intact,while the lower extremities are partially or

WRISTEXTENSORSC6;-(r=~,SIf/I

WRISTFLEXORSC7

TRICEPSC7

~ty4,~~~

SE N SA T ION 1'--__ .~~SC\8\;\~lk

wholly paralyzed, depending upon the degreeof cord damage at that level. The patient can2_~_':'ulate in a variety of ways with correctQ~'::-:;il.'=_ but a wheelchair is still the most prac-ti-::a! means of moving about. A Tl paraplegic-::an drag-to with crutches and bracing but he-::a,,:1ot assume the erect position without,,:':-:-~ 1-el:. T~u:1k stability is absent, and the._._~. :>~ ,:'~2:-"bulation is markedly in-_-:>:: ~-:~~:-:~::.:::-:-J!='ulationis not func-

the nipple and the entire upper extremity havenormal sensation.

Reflexes. The reflexes in the upper extremityare normal.

Upper Motor Neuron ReflexesPathologic reflexes appear in the upper and

lower extremities in association with tet-raplegia. Hoffmann's sign can be elicited in theupper extremity and, if present, is an indica-tion of an upper motor neuron lesion.

To test for Hoffmann's sign, nip the nail of

FIG. 3-8. Hoffmann's sign, indicating an uppermotor neuron lesion.

the middle finger. Normally there should be noreaction at all. A positive reaction producesflexion of the terminal phalanx of the thumband of the second and third phalanx of anotherfinger (Fig. 3-8).

Fractures and Dislocations of the CervicalSpine

Injuries to the cervical spine are a majorcause of tetraplegia. The types of injury in-clude flexion injuries (compression fractures),hyperextension injuries, and flexion-rotationinjuries (cervical facet dislocations).

On occasion, the neurologic level involveddoes not correspond to the skeletal level.Thus, in a fracture-dislocation of the 5th and6th cervical vertebrae, the C6 neurologic levelmay remain functional. Each patient must beevaluated on an individual basis.

Fracture ofCl. The CI or Jefferson fractureis a bursting fracture of the ring of C 1, whichusually decompresses the cord. The fracturecommonly results from a fall, with the patientlanding on his head. If the patient survives,there are usually no permanent neurologicfindings (Fig. 3-9, 3-10).

Fracture of C2. The C2 or hangman's frac-ture is a bursting fracture that separates thebody ofC2 from its posterior elements, therebydecompressing the cord. If the patient sur-

FIG. 3~9. Jefferson fracture, a bursting fracture ofthe ring of CI.

FIG. 3-11. Hangman's fracture, a fracture that sep-arates the body of C2 from its posterior elements.

ODONTOIDPROCESS

vives, there are usually only transient neuro-logic findings (Fig. 3-11, 3-12).

Odontoid Fracture. A fracture at the base ofthe odontoid commonly results from trauma.The patient usually survives. There may betransient neurologic findings, but without theestablishment of the involvement of a specificneurologic level. On occasion, if the trauma is

severe enough, the patient dies. However,there is usually enough space in the cervicalcanal to allow for partial displacement of theodontoid (Fig. 3-13, 3-14).

Fractures of C3-C7COMPRESSION FRACTURES are caused by

hyperflexion injuries of the neck when a ver-tical force ruptures the end plates of the ver-

FIG. 3-15. Cervical compression fracture,caused by hyperflexion of the neck.

88 Cervical Cord Lesion: Tetraplegia

FIG. 3-17. Hyperextension injury of the cervical

spine.tebra and shatters the body. This burstingfracture occurs in both the cervical and lum-bar spines and may involve both the nerveroot and the cord itself (Fig. 3-15). A com-pression fracture of the C5 vertebra, the mostcommon fracture of the cervical spine, in-volves most of the brachial plexus and mayresult in tetraplegia. Compression fractures?oree2.sy to diagnose on roentgenograms (Fig.

"'-'..:~::~:::\~::"slO."I."JURIESof the neck are_.,_. ~__ . _ -::~:~'.~el.sion forces, such as the

_ _._ : ::._,e:i by a rear-end au-: l.. ::...~.:-::~:~-\~_en~i.oninjury is

:c~ ~.,,_~-.:.r· .. ,.:.-:,E't::ea com-~_:.~~ __ ~-:~ •.•••• .;0 :-cdy of

FIG. 3-18. Pain associated with facet joint disloca-

tion.the vertebra; the anterior longitudinal liga-ment is usually ruptured and the cord maywell become involved. Because it is a soft tis-sue injury, the hyperextension injury may notbe obvious on roentgenograms (Fig. 3-17).

CERVICALFACETJOINT DISLOCATIONSareflexion-rotation injuries which may causeneurologic problems. A unilateral facet dislo-cation produces some narrowing of the spinalcanal and neural foramen. Because a unilateralfacet dislocation usually results in less than 50percent anterior dislocation of the vertebralbody, approximately 75 percent of cases haveno neurologic involvement, since the narrow-ing is not sufficient to affect the cord. (Figs. 3-

18, 3-21).BILATERALFACETDISLOCATIONSproducefar greater narrowing of the spinal canal thanunilateral dislocations since, with both facetsdislocated, there is usually greater than 50percent anterior dislocation of the vertebralbody. Because of this greater degree of dislo-cation, approximately 85 percent of patientssuffer neurologic lesions. Because the cervicalspine clepenu~ j)\:\matily on ligaments for itsstability. bilateral facet dislocations, which

/;

~FIG. 3-19. Unilateral facet joint dislocation. (Hop-penfeld, S.: Physical Examination of the Spine andExtremities, Appleton-Century-Crofts.)

FIG. 3-20A, B. In a unilateral facet joint dislocation, there is less than 50 percent anterior dislocation of the vertebral body.

cause the ligaments to tear, rarely heal withsufficient strength to reinstate spinal stability;unless appropriate treatment is undertaken,there is a risk of further damage secondary toany number of possible accidents. Bilateral

FIG. 3-22A, B. Bilateral facet jointdislocation, resulting in greater than50 per cent anterior dislocation ofthe vertebral body.

dislocations may occur at any level, but theyare most common at C5-C6, the level aroundwhich the most movement takes place (exceptfor the specialized articulation at C l-C2) (Fig.3-22, 3-23).

Activities of Daily Living

Respiration. From the above description ofcord lesions, it should be apparent that acomplete transection of the cord at neurologiclevel C3 or higher is incompatible with life,unless the patient is permanently ventilated.Involvement at neurologic levels C4 to C5may cause degrees of respiratory insufficiencythat may threaten life in the presence of rela-tively mild pulmonary disease.

Wheelchair. C6 is the highest neurologiclevel that leaves sufficient innervation of theupper extremity to permit independent manip-ulation of a wheelchair. However, indepen-dent transfer into and out of the wheelchair isstill difficult because of the lack of function ofthe triceps muscle. An active triceps is neededto help lift the body for transfer.

Crutches. Complete cord lesions at neuro-logic level C8 and above are incompatiblewith the use of crutches since the intrinsicmuscles of the hand, needed for strong grip onthe crutches, are nonfunctioning. Functional

FIG. 3-24. The findings re-sulting from a complete lesiondepend upon the anatomicconfiguration of the destruc-tion of neural tissue at a par-ticular level.

walking with crutches is made more difficultboth because of the need to expend two tofour times more energy than in normal ambu-lation and because of a decreased respiratoryreserve. Attempts to encourage walking withbraces and other supports are also rarelysuccessful.

Note that the above is true of complete cordlesions; partial cord lesions show varyingpatterns of neurologic deficiency. Each patientmust be assessed as an individual (Fig. 3-24).

Herniated Cervical DiscsAlthough herniated cervical discs often

cause neurologic root involvement, the cer-vical canal is sufficiently large to accommo-date the herniated disc without significantcord damage, and tetraplegia rarely occurs.However, minor degrees of cord damage - up-per motor neuron lesions - may result from alarge midline herniation. They are usually firstrecognized as a diminution in sensation ofposition and vibration in the lower extremi-ties. In more advanced cases, there may be ac-tual muscle weakness and an increase in thedeep tendon reflexes, as well as early bladdersymptoms.

Tumors of the Cervical SpineTumors of the cervical cord are space-

occupying lesions. They may present as localpain in the spine, and may also radiate pain

into the extremities. The anatomic location ofthe tumor can usually be ascertained by aneurologic evaluation of the extremity. Forexample, a tumor of the cervical cord involv-ing the C6-C7 neurologic segment may causeanesthesia of the middle finger, an absence ofthe triceps reflex, and weakness of finger ex-tension and wrist flexion. Primary tumors ofthe cord rarely give precise neurologic levelsof involvement.

Metastatic tumors in the vertebrae of thecervical spine are not uncommon. Primarybreast and lung tumors frequently metastasizeto the spine. As bone is destroyed, vertebralcollapse and angulation take place and tet-raplegia occurs. The neurologic level of in-volvement usually correlates with the x-rayfindings.

Tuberculosis of the SpineTuberculosis of the spine causes gibbus for-

mation through the destruction of bone. Thespinal angulation may ultimately cause cordcompression and tetraplegia, but the processis far slower than that of trauma. Frequently,neurologic recovery occurs after surgical de-compression and chemotherapy.

Transverse MyelitisTransverse myelitis refers to an inflamma-

tory process in which a spinal cord lesion ex-

tending horizontally across the cord is limitedlongitudinally to one or, at most, a few spinalsegments. Ascending myelitis occurs whenthe lesion spreads proximally.

Transverse myelitis may occur spontane-ously and rapidly following a vaccination, aninfectious illness, or trauma. Although sen-sory and motor loss occurs below the lesion,

complete anesthesia is rare. Flaccid paralysisoccurs initially, but quickly reverts to spasticparalysis.

The neurologic level of involvement canusually be delineated by neurologic level test-ingofsensation, motor power, and reflexes. Thehighest level of sensory loss usually corre-sponds to the segmental site of the cord lesion.

4 Spinal Cord Lesions Below Tl, Including theCauda Equina

PARAPLEGIA

Paraplegia is the complete or partial paraly-sis of the lower extremities and lower portionof the body. It is most frequently caused bytraumatic injury to the spine, but may also de-rive from various diseases, such as transversemyelitis, cystic lesions of the cord, and Pott'sparaplegia (caused by tuberculosis), as well asa host of other pathologies. It occurs rarelyfrom surgical correction of such thoracic prob-lems as scoliosis, as a result of the loss of theappropriate blood supply to the spinal cord,and from the excision of a herniated thoracicdisc.

Below L I, the cauda equina begins; lesionsin this area, called cauda equina injuries,rarely result in full paralysis of the lower ex-tremities.

The following descriptions assume that acomplete lesion exists. Often, however, le-sions are incomplete; the neurologic findingsfor each individual patient must be carefullydetermined, for involvement may vary consid-erably.

Neurologic Levels Tl to T12The level of neurologic involvement can be

determined by tests of motor power and sen-sation. The latter is easier and more accurate.

Muscle Function. The intercostal muscles,as well as the abdominal and paraspinal mus-cles, are segmentally innervated. Intercostalmotion during breathing implies neurologic in-tegrity; a lack of motion implies involvement.The abdominal and paraspinal muscles can besimilarly evaluated, for they are both segmen-tally innervated by T7 to TI2 (Ll). To test forthe integrity of their innervation, have the pa-tient do a half sit up as you palpate the anteriorabdominal wall. As the patient sits up, notewhether the umbilicus is pulled toward any ofthe four quadrants of the abdomen. If theumbilicus is pulled in one direction, the oppos-ing flaccid muscles are denervated (Beevorsign) (Fig. 2-1). Note that the umbilicus is thedividing line between TlO above and TIIbelow. Obviously, this test should not be per-formed during the acute stages of thoraciclesions or with patients who have unstablespines.

Sensation. Sensory innervation may be de-termined in accordance with the chart (Fig.4-1). Special skin landmarks that mark sen-sory areas are:

1. Nipple line- T42. Xiphoid process - T73. Umbilicus- TIO4. Groin- TI2

LI Neurologic Level (LI Intact)Muscle Function. There is complete paraly-

sis of the lower extremities, with the exceptionof some hip flexion from partial innervation ofthe iliopsoas (TI2, Ll, 2, 3).

Sensation. There is no sensation below theL I sensory band, which extends over theproximal third of the anterior aspect of thethigh.

Reflexes. The patellar and Achilles tendonreflexes are absent when spinal shock ispresent. As spinal shock wears off, the re-flexes become exaggerated.

Bladder and Bowel Function. The bladder(S2, 3, 4) does not function. The patient can-not urinate in a stream. The anus is initiallypatulous, and the superficial anal reflex (S2, 3,4) is absent. As spinal shock wears off, theanal sphincter contracts and the anal reflexbecomes hyperactive.

L2 Neurologic Level (L2 Intact)Muscle Function. There is good power in hip

flexion because the iliopsoas is almost com-pletely innervated. The adductor muscles arepartially innervated (L2, 3,4) and show dimin-ished power. Although the quadriceps (L2, 3,4) are partially innervated, there is no clini-cally significant function. No other muscles inthe lower extremity have innervation, and theunopposed action of the iliopsoas and adduc-tors tends to produce a flexion and slight ad-duction deformity.

Sensation. There is no sensation below theL2 sensory band, which ends two-thirds ofthe way down the thigh.

Reflexes. The patellar reflex receives inner-vation from L2, 3, and 4, but the L2 contribu-tion is small.

Bladder and Bowel Function. There is no vol-untary control.

L3 Neurologic Level (L3 Intact)Muscle Function. In addition to the iliopsoas

and adductors, the quadriceps, althoughslightly weak, (L2, 3, 4) show significantpower. No other muscle groups are function-ing. Thus, the hip tends to become flexed, ad-ducted, and externally rotated, while the kneeremains extended.

Sensation. Sensation is normal to the level ofthe knee (L3 dermatome band).

Reflexes. The patellar reflex (L2, 3, 4) ispresent, but decreased. The Achilles tendonreflex is absent.

Bladder and Bowel Function. There is no vol-untary control.

L4 Neurologic Level (L4 Intact)Muscle Function. Muscle function at the hip

and knee is the same as in L3 neurologiclesions except that quadriceps function is nownormal. The only functioning muscle belowthe knee is the tibialis anterior (L4), whichcauses the foot to dorsiflex and invert.

Sensation. In addition to the entire thigh, themedial side of the tibia and foot have sensa-tion.

Reflexes. The patellar reflex (predominantlyL4) is normal; the Achilles tendon reflex (81)is still absent.

Bladder and Bowel Function. There is no vol-untary control of either function.

L5 Neurologic Level (L5 Intact)Muscle Function. The hip still has a flexion

deformity, because the gluteus maximus doesnot function. The gluteus medius (Ll-S1) haspartial function; it counteracts the action ofthe adductors. The quadriceps are normal.

The knee flexors function partially with themedial hamstrings (L5) present and the lateralhamstrings (S 1) absent.

The foot dorsiflexors and invertors func-tion. Since the plantar-flexors and evertors arestill absent, the foot tends to develop a cal-caneus (dorsiflexion) deformity.

Sensation. Sensation is normal in the lowerextremity, with the exception of the lateralside and plantar surface of the foot.

Reflexes. The patellar reflex is normal. TheAchilles tendon reflex is still absent.

Bladder and Bowel Function. There is no vol-untary control of either function.

Sl Neurologic Level (Sl Intact)Muscle Function. The hip muscles are nor-

mal, with the exception of slight gluteus max-imus weakness. The knee muscles are normal.The soleus and gastrocnemius (81, 2) areweak, and the toes show clawing as a result ofintrinsic muscle weakness (S2, 3).

Sensation. Sensation in the lower extremityis normal. There is perianal anesthesia.

Reflexes. The patellar and Achilles tendonreflexes are normal, since the S2 contributionto the Achilles tendon reflex is small.

Bladder and Bowel Function. There is still novoluntary control of either function.

Pathologic Reflexes

Pathologic reflexes can be elicited in thelower extremities in association with para-plegia. Babinski's sign and Oppenheim's signare two pathologic reflexes which indicate anupper motor neuron lesion.

Babinski's Sign. Elicit the plantar responseby running a sharp instrument across the plan-tar surface of the foot, and along the calcaneusand lateral border of the forefoot. Normally, ina negative reaction, the toes plantarflex. Apositive reaction (Babinski's sign) occurswhen the great toe extends as the other toessplay (Fig. 4-2). This sign indicates an uppermotor neuron lesion - a corticospinal tract in-volvement. To ascertain the level of the le-sion, correlate this sign with other neurologicfindings. In young infants, the presence ofBabinski's sign is normal rather than patho-logic. However, this response should disap-pear by 12 to 18 months of age.

Oppenheim's Sign. To elicit Oppenheim'ssign, run your finger along the crest of thetibia. Normally there should be no reaction atall, or the patient should complain of pain.Under abnormal circumstances, the reactionis the same as it is in plantar stimulation: thegreat toe extends as the other toes splay (Op-penheim's sign) (Fig. 4-3). Oppenheim's signis not as reliable as Babinski's sign and shouldbe used as a confirmation of a positive Ba-binski's sign.

Normal Superficial Reflex

Cremasteric. The lack of the cremastericreflex may be due either to the loss of thereflex arc or to an upper motor neuron lesion.However, absence of the reflex in associationwith the presence of a pathologic reflex (Ba-binski's or Oppenheim's signs) supports thediagnosis of an upper motor neuron lesion.

To elicit the superficial cremasteric reflex,stroke the inner side of the upper thigh withthe sharp end of a neurologic hammer. If thereflex is intact, the scrotal sac on that side willbe pulled upwards as the cremaster muscle(T12) contracts. If the cremasteric reflex isunilaterally absent, there is probably a lowermotor neuron lesion between Ll and L2 (Fig.4-4).

iFIG. 4-4. The cremasteric reflex. (Hoppenfeld, S.:Physical Examination of the Spine and Extremities,App leton -Century -Crofts.)

Further Evaluation of Spinal Cord Injuries

Complete or Incomplete Lesion. The possibil-ity of cord return, and whatever partial func-tional recovery it may provide, depends uponwhether the lesion is complete or incomplete,whether the cord is completely severed oronly partially severed or contused. Injuries inwhich no function returns over a 24-hourperiod are assumed to be complete lesionswhere no return of cord function will occur. Acomplete neurologic examination is needed toconfirm such a diagnosis. If, however, there ispartial return of function in the initial period,the lesion is probably incomplete, and morefunction may eventually return. Functionmust return at more than one neurologic levelto support such a diagnosis, however, since re-turn at only one level may simply indicate thatthe nerve root at the level of the lesion has

•I II

'(II II II

been partially damaged or contused. Suchsingle level return gives no indication as towhether the lesion below it is complete or in-complete. The recovery of this single nerveroot is considered to be a root lesion (ratherthan a cord lesion) of the root originating justproximal to the injured portion of the cord.Functional return of muscle strength fromsuch an injury may occur at any time; prog-nostication for root return is good as late as sixmonths after the initial injury.

Sacral Sparing. The best indicator of thepossibility of cord return is sacral sparing, inwhich the sacral nerves are partially or whollyspared injury because of their location on theperiphery of the cord. Evidence of sacral spar-ing is evidence of an incomplete lesion. Itenhances the possibility of partial or complete

return of motor power as well as of bladderand bowel function.

Sacral sparing can be evaluated throughthree tests of motor, sensory, and reflex inner-vation:

1. Muscle testing of flexion of the greattoe (S 1 innervation)

2. Sensory testing of the perianal area(S2, 3,4)

3. Reflex testing of the anal sphinctermuscle (S2, 3, 4)

Since the bladder and bowel are innervated bythe sacral nerves (S2, 3, 4), testing of thesethree areas gives a valid indication of thedegree of sacral sparing and the possibility ofreturn of function (Fig. 4-5).

Flaccidity and Spasticity. Immediately afterany trauma causing tetraplegia or paraplegia,

the spinal cord experiences spinal shock, re-sulting in the loss of reflexes innervated by theportion of the cord below the site of the lesion.The direct result of spinal shock is that all themuscles innervated by the traumatized portionof the cord and the portion below the lesion, aswell as the bladder, become flaccid. Spinalshock wears off between 24 hours and threemonths after injury, and spasticity may re-place flaccidity in some or all of these muscles.Spasticity occurs because the reflex arc to themuscle remains anatomically intact despitethe loss of cerebral innervation and control viathe long tracts. During spinal shock, the arcdoes not function; as the spine recovers fromshock, the reflex arc begins functioning with-out the inhibitory or regulatory impulses fromthe brain, creating local spasticity and clonus.Initially absent deep tendon reflexes maytherefore become hyperactive as spinal shockends. Such spasticity may be useful in increas-ing function by, for example, assisting in emp-tying the bladder and bowel.

Prognostication of Ambulatory Function.Thoracic lesions, if they are complete, createsimilar problems regardless of the level of in-volvement. Since the thoracic cord does notsupply innervation to any extremity, a com-plete thoracic lesion at any level leaves the pa-tient paraplegic. The major diagnostic consid-eration in determining the neurologic level isthat of sensory innervation to the trunk and, toa lesser extent, innervation of the abdominalmusculature. In prognosticating the patient'sfuture performance, it is important to assessthe function of the segmentally innervated ab-dominal and paraspinal muscles that aid in bal-ance for sitting, standing, and walking duringrehabilitation.

Tl TO T8. In general, whereas a paraplegicwith a lesion anywhere from T 1 to T8 can beindependent in all wheelchair activities, themore complex motions, such as getting upfrom the floor and curb jumping with a wheel-chair, are more difficult for those with lesionsfrom Tl to T4.

T6. A T6 paraplegic has complete upper ex-tremity and thoracic musculature, and canstabilize himself against his pectoral girdle.

T9 TO T12. A paraplegic with a lesion fromT9 to T 12 can walk independently with longleg braces and crutches.

Ll TO L3. A paraplegic with a lesion fromLito L3 and pelvic stability can ambulatewith long leg braces and forearm crutches ifhewishes.

L4 TO S2. A paraplegic with a lesion fromL4 to S2 can exist independent of his wheel-chair using short leg braces and forearmcrutches. He is completely independent in allactivities.

Although paraplegia may result from a le-sion located anywhere from T 1 to L 1, themost common site for a lesion is between T12and Ll. The facet joints between T12 and Llare lumbar in nature and face laterally, whilethose between the other thoracic vertebrae arethoracic in nature, and face vertically (Fig.4-6). Thus, the angle between the facet jointsof T 12 and L 1 is in the sagittal plane, permit-ting more flexion than the frontal alignment ofthe thoracic joints. Many of the other thoracicvertebrae are further limited in their motion bythe rib cage. This greater concentration of mo-tion at the TI2-Ll articulations leads to apoint of stress and a greater potential for frac-ture and subsequent paraplegia (see Fig.4-13).

Note that there is very little room in the spi-nal canal at this level; any vertebral disloca-tion is almost certain to cause neurologicproblems as a result of direct pressure on thecord. Extreme flexion and rotation is the causeof fracture-dislocation of the thoracic spine,and usually leads to paraplegia.

Prognostication of Bladder and Bowel Func-tion. Restoring useful function to the bladderand bowel and thus a catheter-free state iscrucial for tetraplegic and paraplegic patients.A bladder which must be regularly emptiedthrough a catheter is prey to repeated infec-tions and excessive autonomous dysreflexia

During the atonic period, the bladder cannotcontract by reflex action and must be cath-eterized or emptied by manual pressure on thelower abdomen. To empty the bowel will re-quire enemas as well as manual evacuation ifthe stool is inspissated. As the atonic phasepasses, the bladder begins to contract reflexly,and the patient can be trained to empty it byusing its reflex action.

Herniated Thoracic Discs

The thoracic spine has the advantage of at-tachment to the ribs and sternal plate, whichsplint the vertebrae and provide added stabil-ity. With less motion, there is less chance fordisc herniation and fracture and subsequentneurologic problems. Thus, thoracic herniateddiscs are rare in comparison to cervical andlumbar herniated discs.

Herniated thoracic discs usually producecord involvement, while lumbar and cervicaldiscs usually produce nerve root involvement.Because there is little extradural space in thethoracic spinal canal, a comparatively smalldisc protrusion may have pronounced effects

on the neurology (Fig. 4-8). It is more difficultto make a clinical diagnosis of a herniated tho-racic disc than a herniated cervical or lumbardisc. Although evaluation of muscle power,reflexes, sensation, and bladder and bowelfunction can assist in determining the level ofinvolvement, the myelogram is the corner-stone for establishing the diagnosis. Note thatwith herniated thoracic discs paraplegia occa-sionally occurs.

Motor power is impaired, but not in a myo-tomal or neurologic pattern. Proximal and dis-tal muscle groups are equally weak, and legweakness may be unilateral or bilateral.Weakness of the lower abdominal musclesmay be apparent, a situation which can beevaluated by Beevor's sign (see page 45).Muscle weakness may vary from mild paresisto complete paraplegia. Muscle tone is in-creased in most patients, as one would expectin an upper motor neuron lesion.

Sensation. Examination can determine thelevel of sensory involvement. Usually it is oneor two levels lower than the bony level de-picted on a myelogram.

Reflexes. Deep tendon reflexes: patellar and

POSTERIOR LIGAMENTOUS

COMPLEX

INTERSPINOUSL1G.

LIGAMENTUMFLAVUM

Achilles tendon reflexes are increased, brisk,or exaggerated.

Superficial reflexes: abdominal and cremas-teric reflexes are absent.

Pathologic reflexes: Babinski's and Op-penheim's signs are usually present (Fig. 4-2,4-3).

Bladder and Bowel Function. Most patientshave no bladder or bowel symptoms. Occa-sionally, a patient may experience urinary re-tention.

It should be clear from the above discussionthat the signs vary depending upon the extentof the herniation. The variations themselvesmay be a tip-off to the diagnosis.

EVALUATION OF SPINAL STABILITY TOPREVENT FURTHER NEUROLOGIC

LEVEL INVOLVEMENT

After spinal trauma, it is crucial to deter-mine whether the spine is stable or unstable inorder to protect the spinal cord. If the spine isunstable, it must be stabilized immediately toprevent further damage to the cord, and possi-

ble tetraplegia and paraplegia. The name ofthe game is to protect the spinal cord.

Diagnosis

The diagnosis of an unstable spine is basedon the history of the mechanism of injury, thephysical examination, and an x-ray examina-tion. Stability depends essentially on the integ-rity of the posterior ligamentous complex,which consists of:

1. Supraspinous ligament2. Interspinous ligament3. Facet joint capsule4. Ligamentum flavum (Fig. 4-9).

The breakdown of this ligamentous complexcan be diagnosed by specific criteria as shownin Table 4-1.

Roentgenography, the cornerstone of thediagnosis of instability, shows whether there isseparation of the spinous processes, disloca-tion of the articular processes, and fracture.

Physical examination determines whetherthere is a palpable spinal defect (Fig. 4-10).

History may establish whether the injurywas caused by flexion-rotation or excessiveflexion. Direct longitudinal pull rarely rup-tures fibers of the posterior ligamentous com-

FIG. 4-10. A palpable spinal defect indicating anunstable spinal injury.

History ofMechanism of Physical and X-ray ExaminationInjury Neurologic Examinations Specific Criteria

Flexion-rotation Palpable spine defect Spinous process separationExcessive flexion Motor/reflex/ sensation Articular process dislocation

alteration and/or fractureAbrasions on the back

Disruption of posterior Disruption of posterior Disruption of posteriorligamentous complex ligamentous complex ligamentous complex

Physical ExaminationHistory of Integrity of NeurologicMechanism of Posterior Long. Findings Palpable SpineInjury Stability Ligament Complex (N.F.) Defect (P.S.D.) X-ray Findings

Flexion Stable Intact Occasional P.S.D. VertebralN.F. body crush

or dislocationExcessive Unstable Not intact Occasional

flexion N.F.Extension Stable Intact Occasional None None

N.F.Flexion- Unilateral: Not intact N.F. P.S.D. Facet dislocation

rotation stableBilateral:

unstable

plex. However, direct longitudinal pull com-bined with rotation frequently ruptures fibersand results in spinal instability. Ligamentoushealing is simply not strong enough to ensurespinal stability: a spine fusion is almost alwaysnecessary. If the fracture-dislocation does notdisrupt the posterior ligamentous complex,bone healing is usually strong enough to en-sure stability.

Flexion Injury

If, during flexion injury, the posterior liga-ment and complex remains intact, the force offlexion is spent on vertebral body, and awedge compression fracture occurs. The ver-

tebral end plates remain intact, and thespinous processes are only minimally sepa-rated. A wedge compression fracture is mostoften seen in the cervical and lumbar spines,and is considered a stable fracture; the bonefragments are firmly impacted and the poste-rior ligamentous complex, including the ante-rior and posterior longitudinal ligaments, re-mains intact (Fig. 4-11).

Excessive flexion results in tearing of theposterior ligamentous complex and disengage-ment of the posterior facet joints, leading topure dislocation. The spinous processes areseparated, and the vertebral bodies remainuncrushed since there is no fulcrum around

FIG. 4-13. A flexion-rotation injury resulting in afracture-dislocation of the spine.

FLEXION-ROTATION INJURYUNSTABLE

FIG. 4-14. Anatomy of an unstable flexion-rotationinjury.

which to compress them. This injury is morecommon in the cervical spine than in the lum-bar spine; it does not occur in the thoracicspine because of the stability offered by theribs and sternal plate. Pure dislocations suchas these are unstable (Fig. 4-12, Table 4-2).

Flexion-Rotation InjuryFlexion-rotation injury results in fracture-dislocations of the spine (Fig. 4-13). The pos-terior ligamentous complex ruptures, the ro-tating spine dislocates at the facet joints, andthe articulating processes fracture. A slicefracture may also occur in the vertebra belowthe facet dislocation. In addition, the spinousprocesses are pulled apart and laterally dis-placed (Fig. 4-14). This type of injury is con-sistently associated with paraplegia. In thethoracolumbar area it is very unstable andmust be protected, for a partial lesion, or evena cord still untouched, can be converted into acomplete lesion (Fig. 4-10, 4-15, Table 4-3).

Hyperextension injuriesIn hyperextension injuries (to the cervical

spine), the anterior longitudinal ligament andannulus are disrupted and extension-disloca-tion occurs. The injury becomes stable if theneck is held in flexion. Frequently, roentgeno-grams taken with the neck in flexion are nega-tive.

Compression InjuriesIn compression injuries, the posterior liga-

mentous complex and the anterior and poste-rior longitudinal ligaments remain intact, andthe spinous processes are not separated. Thespine remains stable. However, a fragmentthat bursts posteriorly may compress the cordand cause tetraplegia in the cervical spine andparaplegia in the lumbar spine.

Physical ExaminationHistory of Integrity of the NeurologicMechanism of Posterior Ligament Findings Palpable SpineInjury Stability Complex (N.F.) Defect (P.S.D.) X-ray FindingsFlexion Stable Intact None None Wedge vertebrae,

minimal sepa-ration of thespinal process

Excessive Unstable Not intact N.F. P.S.D. Pure vertebralflexion body disloca-

tion. Separa-tion of the spi-nous process

Flexion- Unstable Not intact N.F. P.S.D. Spinous processrotation* Most unsta- separation. Ar-

ble of all ticular processvertebral in- dislocation &juries. fracture. Wedge

slice of thelower ver-tebra

Compression Stable Intact Rare N.F. None Burst vertebrae.Spinousprocesses notseparated. Ver-tebral body isshattered.Fragment maybe displaced.

Extension Stable Intact. Rare in- N.F. None Nonejury. (most com-mon in cervicalspine)

5 ~eningounyelocele

Determining the level of neurologic involve-ment in meningomyelocele is crucial. It per-mits the evaluation of the following five majorfunctional criteria:

1. Determination of the extent of muscularimbalance around each of the majorjoints of the lower extremity.

2. Evaluation of the degree and character ofany deformity.

3. Assessment of remaining function andthe need for bracing or surgery.

4. Evaluation of bladder and bowel func-tion.

5. Baseline analysis for long term follow-up.

Although the defect frequently causes a totalloss of innervation below it, this is not alwaysso. In many cases, there will be partial inner-vation of several levels below the major levelof involvement, or partial denervation of sev-erallevels above it. It is therefore necessary todetermine not only the level which seems tobe primarily involved, but also the extent towhich other levels may be affected. The level

of involvement can be determined throughmuscle testing, sensory testing, reflex testing,examination of the anus, and evaluation ofbladder function.

It is easier to test a newborn infant than achild. In the infant, the skin can be pinched toprovide a painful stimulus and the musclebeing tested can be palpated for contraction:the muscle will either react (positive indica-tion of muscle function) or will remain inactive(indication of no muscle function). Although itis difficult to grade muscle strength accuratelyin an infant, it will be evident from palpationand observation whether the muscle is func-tioning at a minimum of grade three. The in-fant's muscular function can also be tested byappropriate electrodiagnostic studies such aselectromyography and muscle stimulationtests. Children are more difficult to test be-cause they may refuse to respond, forcing theexaminer to test many times to obtain an accu-rate evaluation. In addition, muscle grading isa necessity as soon as it is possible, especiallywhen a child is old enough to cooperate, sincethe child may lose muscle power or the cordlevel of involvement may ascend, reducing

functional capacity. As a result of such shift-ing involvement, further evaluation and surgi-cal intervention may be necessary.

Deformities that result from meningomyelo-cele are usually caused by muscle imbalance.If the muscles around the joint are not work-ing or if all muscles are functioning equallywell, deformities seldom develop. It is usuallywhen a muscle is working either unopposed oragainst a weakened antagonist that a deform-ity occurs. A mild muscle imbalance actingover a prolonged period oftime may produce adeformity. Development of muscle imbalanceafter birth as a result of the involvement of ad-ditional neurologic levels may also lead todeformities. They may also appear as a resultof postural problems if braces or splints are in-correctly applied, if the limbs remain con-stantly in one position until they becomefixed, or if the patient is allowed to lie in oneposition in his crib (in most instances, the hipsflex, abduct, and externally rotate, the kneesflex, and the feet move into a few degrees ofequinus).

Once a fixed deformity has developed, ittends to remain, even if the muscular imbal-

TABLE 5-1. MOTOR TESTING FOR NEUROLOGICLEVEL

Joint Action LevelHip Flexion T12, Ll, L2, L3

Extension Sl

Adduction L2,L3,L4Abduction L5

Knee Extension L2,L3, L4Flexion L5, Sl

Ankle Dorsiflexion(Ankle extension) L4,L5

Plantar flexion(Ankle flexion) Sl, S2

Inversion L4Eversion Sl

ance disappears. For example, if nerve rootshigher than the original lesion become in-volved, an existing deformity will usually notcorrect itself even though the previously un-opposed muscle has ceased to function.

Evaluate the neurologic or cord level of in-volvement by motor testing each of the jointsof the lower extremity. Then review the infor-mation within the broader concepts of neuro-logic levels to establish the diagnosis (Table5-1 ).

The following meningomyelocele examina-tion will evaluate each possible level of in-volvement from L 1-L2 to S2-S3, its functionaldeficits, and its potential for causing deformity(Fig. 5-1).

LI-L2 Neurologic Level (Ll is intact,L2 is not)

Motor FunctionHIP

Flexion:Extension:

absentabsent

Adduction: absentAbduction: absent

No function; there may be some hip flexionfrom the partial innervation of the iliopsoas(T12, Ll, 2, 3).

KNEE

Extension: absentFlexion: absent

No function, no deformity.FOOT

Dorsiflexion: absentPlantarflexion: absentInversion: absentEversion: absent

No function; if there is any deformity, itmay be a result of either the intrauterine posi-tion, a loss of function where there wasonce a muscle imbalance, or a crib positionthat has produced hip and knee flexion con-tractures and equinovarus deformity of thefoot. The foot normally has a few degrees ofequinus when at rest, a position which maybecome fixed.

Sensory Testing. There is no sensation belowthe L 1 band, which ends approximately one-third of the way down the thigh.

Reflex Testing. None of the deep tendonreflexes of the lower extremity function. Oc-casionally, reflex activity may occur as a re-suIt of the functioning of a portion of the cordbelow the involved neurologic level (intactreflex arc).

Bladder and Bowel Function. The bladder(S2, S3, S4) is nonfunctioning, the patient isincontinent, the anus is patulous, and the analwink (S3, S4) is absent. It should be noted thatsacral sparing is not uncommon at any level.Lesions which give a pattern of involvement

in the sacrally innervated leg muscles but ade-quate innervation of the sphincter muscles arealso common.

L2-L3 Neurologic Level (L2 is intact,L3 is not)

Motor FunctionHIP

Flexion: partialExtension: absentAdduction: partialAbduction: absent

Flexion is considerable, since iliopsoas is al-most completely innervated. There is, in addi-tion, a hip flexion deformity because the ilio-psoas is unopposed by the major hir extensor,the gluteus maximus (S 1, 2). There is a smalldegree of hip adduction, with a correspondingslight adduction deformity because the adduc-tor group (L2, 3, 4) is partially innervated andis unopposed by the main hip abductor, thegluteus medius (L5, Sl).

KNEE

Extension: partialFlexion: absent

The knee is not deformed in spite of thesmall amount of function of the knee extensor,the quadriceps (L2, 3,4). There is no signifi-cant clinical function.

FOOT.No function, no muscular deformity,except as above.

Sensory Testing. There is no sensation belowthe L2 band, which ends two-thirds of the waydown the thigh.

Reflex Testing. None of the lower extremityreflexes are functioning.

Bladder and Bowel Function. There is nofunction of the bladder and bowel. The pa-tient cannot urinate in stream when he isquiet; he is only able to dribble urine. Astream may appear if the patient is crying as aresult of the tightening of the rectus ab-dominus muscle and the corresponding In-crease in intra-abdominal pressure.

I

l,;- .~g:~~

~

l.~

co,,~~

~·~r~ ~~&1~

~ FLAIL

FIG. 5-2A B ~T~~ FOOT AND ANKLE

, . Neurologic Level L3-L4' . motor function.

SENSATION\

NOTFUNCTIONING

(PATULOUS)

FIG. 5-3. Neurologic level L3-L4: sensation, reflex, bladder and bowelfunction.

L3-L4 Neurologic Level (L3 is intact,L4 is not)Motor Function (Fig. 5-2)HIP

Flexion: presentExtension: absentAdduction: presentAbduction: absent

The hip has flexion, adduction, and lateralrotation deformities.

KNEE

Extension: presentFlexion: absent

The knee is fixed in extension by the unop-posed quadriceps.

FOOTDorsiflexion: absentPlantarflexion: absent

Inversion: absentEversion: absent

There are still no active muscles in the foot.

Sensation Testing (Fig. 5-3). Sensation isnormal to the knee. Below the knee, there isno sensation.

L 4 FUNCTIONING;; I. 1/;;;;;;;; 0'$;/ W

NOT

FUNCTIONI NG

( PATULOUS)

FIG. 5-5. Neurologic level L4-L5: sensation, reflex, bladder and bowelfunction.

viously diminished, patellar reflex (L2, 3, 4),since the reflex is primarily L4.

Bladder and Bowel Function. No function.

L4-LS Neurologic Level (L4 is intact,LS is not)

Motor Function (Fig. 5-4)HIP

Flexion: presentExtension: absentAdduction: presentAbduction: absent

The hip has both flexion and adductiondeformities, since the iliopsoas and adductormuscles are still unopposed. Such an unop-

posed adduction may well result over a time ina dislocated hip and, eventually, a fixedflexion-adduction deformity. For ambulation,full leg bracing will be necessary, including theuse of a pelvic band, since the hip is unstablewithout extension and abduction. Surgery isalso a possible solution.

KNEE

Extension: presentFlexion: absent

The knee has an extension deformity as aresult of the unopposed action of the quadri-ceps. The main knee flexors, the medial andlateral hamstrings (L5 and S 1), are dener-vated. An extended knee is relatively stable,

L 5 FUNCTIONING•

SENSATIONI

f-. ~C

) ,

~

FIG. 5-7. Neurologic level L5-Sl: sensation, reflex, bladder and bowelfunction.

and future bracing is not necessary. However,since the hip must be braced, (unless surgeryis performed), the knee is also braced.

FOOT Dorsiflexion: partialPlantarflexion: absent

Inversion: partialEversion: absent

The only functioning muscle in the foot isthe tibialis anterior (L4) because everythingelse is innervated by L5, S I, S2, and S3. Theinsertion of the tibialis anterior on the medialside of the foot at the first metatarsal-cuneiform junction causes the foot to be dor-

siflexed and inverted. In this position, the footis both unbalanced and unstable, and the tib-ialis anterior may have to be surgically re-leased. The foot is not plantigrade and iswithout sensation; thus, skin breakdown mayoccur. Bracing is necessary, but fitting shoesand getting the foot into a brace may be dif-ficult if some correction is not achieved.

Sensory Testing (Fig. 5-5). Sensation ex-tends to the medial side of the tibia and foot.The lateral aspect of the tibia (L5) and themiddle and lateral portions of the dorsum ofthe foot are anesthetic. A pinprick is the mosteffective way to test infants for sensation; if

51W;

FUNCTIONING~

~~

c5~ LIl

L2

~

~L3

S~ ~

LATERALHAMSTRING

~tion at these joints. Such a general triple reflexresponse may occur even if the patient is com-pletely paralyzed.

Reflex Testing. The patellar reflex (predomi-nantly L4) functions, whereas the tendon ofAchilles reflex (S 1) does not. If there is hy-peractivity in the tendon of Achilles reflex, aportion of the cord below the original lesionhas developed with intact nerve roots, withoutconnection to the rest of the cord. Thus, theS 1 ankle reflex arc is intact, and only the in-hibitory and controlling factor of the brain ismissing.

Bladder and Bowel Function. Neither thebladder nor the bowel function.

FIG. 5-8A, B. Neurologic level 81-82: motor func-tion. L5-S1 Neurologic Level (L5 is intact, SI

is not)Motor Function (Fig. 5-6)HIP

Flexion: presentExtension: absent

there is sensation, the child cries or moves theextremity. A triple response to the pinprick(flexion of the hip and knee, dorsiflexion of thefoot) should not be confused with motor func-

NOTFUNCTIONING

(PATULOUS)

FIG. 5-9. Neurologic level Sl-S2: sensation, reflex, bladder and bowel func-tion.

Adduction: presentAbduction: present

There is a flexion deformity of the hip, sincethe gluteus maximus is not working. There isnow a balance between adduction and abduc-tion; however, a minimal adduction deformitymay still exist since the gluteus medius, par-tially supplied by 81, is slightly weak. Becauseof this partial balance, there is usually no hipdislocation. However, if the gluteus medius isexcessively weak, the hip may later sublux.For ambulation, bracing or surgery will be

necessary to prevent severe fixed flexion de-formity.

KNEE

Extension: presentFlexion: partial

The knee is relatively well balanced, andthere are no deformities. The extensors areworking; the flexors are functioning in part,with the medial hamstrings (L5) in and the lat-eral hamstrings (81) out. Because ofthis, theremay be a slight weakness in flexion. Bracingwill be unnecessary.

FOOTDorsiflexion: presentPlantarflexion: absentInversion: presentEversion: absent

The dorsiflexors all function. Therefore, thefoot will have only a dorsiflexion deformity(calcaneal foot).

Sensory Testing (Fig. 5-7). Sensation is ab-sent on the lateral side and plantar surface ofthe foot. Elsewhere, it is normal.

Reflex Testing. The tendon of Achilles reflexis still absent.

Bladder and Bowel Function. The bladderand bowel are still nonfunctional.

SI-S2 Neurologic Level (SI intact, S2 isnot)

Motor Function (Fig. 5-8)HIP

Flexion: presentExtension: partialAdduction: presentAbduction: present

The hip is almost normal; there may beslight gluteus maximus weakness.

KNEE

Extension: presentFlexion: present

The knee is normal and well balanced.FOOT

Dorsiflexion: presentPlantarflexion: partialInversion: presentEversion: present

The toes of the foot may become clawed,since the intrinsic muscles are still not func-tioning. In addition, plantar flexion is stillweak. Future gait will show weakened or ab-sent toe-off, and the forefoot may be brokenon the hindfoot from muscle imbalance (cal-caneovalgus of the forefoot). The foot mayhave a vertical or dislocated talus (convex pesvalgus).

Sensory Testing (Fig. 5-9). Sensation is nor-

mal except for the posterior strip in the thighand leg and on the sole of the foot (S4).

Reflex Testing. The tendon of Achilles re-flex, although it functions, may be slightlyweakened. The reflex is predominantly an S 1reflex with elements of S2.

Bladder and Bowel Function. The bladderand bowel are still not functioning.

S2-S3 Neurologic Level (82 intact, 83 isnot)

Motor FunctionHIP. Normal.KNEE. Normal.FOOT. The toes of the foot may become

clawed in time; there may also be a cavovarusdeformity.

Sensory Testing. Sensation is normal.Reflex Testing. Reflex is normal.Bladder and Bowel Function. There is often

some bladder activity; a portion of the analwink is present.

Sitting, standing, and walking are three de-velopmental indicators that are useful in deter-mining the future gross motor functional ca-pacity of the patient. Most patients withmeningomyelocele experience some delay inreaching these milestones; the amount ofdelay and degree of difficulty that they en-counter provides valuable information as tothe course of future rehabilitation.

Sitting. Normally, a child learns to balancehimself while sitting at six months of age, andcan pull himself to a sitting position at seven toeight months. A child with a lesion above L3sits late - at approximately ten months - dueto muscle weakness around the hips. A childwith a high thoracic lesion may have spinal in-stability, forcing him to balance himself, withthe help of his hands, in the tripod position. Aspinal fusion stabilizes the spine, freeing thehands for activities of daily living.

Standing. A child is normally able to pull

himself to a standing position at nine to tenmonths. A child with a thoracic meningomye-locele is unable to do this, no matter what thelevel of lesion. He should thus be offered brac-ing for stability; he may still experience somedifficulty, however, because braces are bothheavy and cumbersome.

Walking. Ambulation normally begins at 12to 15 months (range; 8 to 18 months). Al-though almost all children with meningomye-locele have problems with ambulation, inde-pendent ambulation with the aid of ap-pliances is possible for those with normalintelligence and involvement in the lum-bosacral region. Children are usually more ex-tensively braced than they would be as adultsuntil they reach midadolescence (12 to --1-5years). After that time, most patients withlesions higher than S 1 will become limitedambulators because of the excessive energythat must be expended as a result of the weighttheir arms must bear; ambulation with bracesand crutches requires as much energy as run-ning at top speed.

Bifid cords with widely discrepant levels offunction are not uncommon. There is a seriouspossibility that a bony or cartilaginous spurwill cause tethering of the cord as the columngrows (diastomatomyelia) (Fig. 5-10); anysign of such unilateral loss of function is an in-dication for a myelogram. Scoliosis, the lateralcurvature of the spine, is a significant con-comitant problem for those in this group.

From 50 percent to 70 percent of childrenwith meningomyelocele develop hydrocepha-lus, an abnormal increase in the ventricularsize, resulting in enlargement of the head andabnormal prominence of the forehead. Hydro-cephalus usually develops secondary to Ar-nold-Chiari malformation (caudal displace-

Fig. 5-10. Diastomatomyelia (Hoppenfeld, S.: J.Bone Joint Surg., 493:276, 1967).

ment of the brain stem). If it is left unattended,it can lead to spasticity that may further de-crease already compromised muscle functionon either marginally or normally innervatedmuscles. If hydrocephalus is treated early,ventricular size, and thereby head circumfer-ence, can be maintained within normal limits.The usual method of therapy is with a shuntand appropriate revisions, if necessary. Theshunt is a tube that drains excess spinal fluidfrom the ventricles of the brain to the peri-toneal cavity or heart.

EXAMINATION OF THE UPPEREXTREMITY

Although the great majority of meningo-myelocele lesions occur in the lumbosacralregion, higher lesions affecting the function ofthe upper extremity may occur in associationwith these lower lesions, necessitating a com-plete neurologic evaluation of the upper ex-tremity. Hydromyelia (enlargement of the cen-tral canal of the spinal cord) and syrin-

FIG. 5-11. Position for testing the hamstring andgluteus maximus muscles.

gomyelia (liquid filling abnormal caVItIesin the substance of the spinal cord) of the cer-vical cord may also occur in association withmeningomyelocele of the lumbar and sacralregions. Both these pathologies are progres-sive and require careful motor and sensorytesting of the upper extremity with provisionsfor follow-up care. To patients with meningo-myelocele, the upper extremities are particu-larly important because of their use in crutchwalking.

SUGGESTIONS FOR EXAMINATION OFTHE PATIENT WITH

MENINGOMYELOCELE

1. Do not mistake the withdrawal responsefor voluntary control of motor power. Eventhough a pin-prick stimulus may cause with-drawal at three joints - hip flexion, knee flex-

FIG. 5-12. Contraction of the medial hamstringmuscle indicates integrity of L5 neurologic level;contraction of the lateral hamstring muscle in-dicates integrity of S 1 neurologic level.

ion, and ankle dorsiflexion (the triple re-sponse) - the infant does not necessarily feelthe noxious stimulus. It is necessary to watchthe child for signs of crying and changes infacial expression to determine whether thereexists a central recognition of pain.

2. To muscle test the hamstrings, positionthe patient face down on the edge of the ex-amining table, so that his hips and lower ex-tremities hang freely (Fig. 5-11). Stabilizehim. Then determine whether he can flex hisknees. If the knee flexes, it is working againstgravity and is acting with at least grade threestrength (Fig. 5-12). During testing, palpatemedially to determine activity of the semi-membranosus and semitendinosus (L5) andlaterally for the biceps femoris (S 1).

3. To muscle test the gluteus maximus,continue to hold the patient in the same posi-tion and have him extend his hips, indicating

gluteus maximus activity (S1) (Fig. 5-13).4. It is by far easier to evaluate function in

young children by playing with them than byconducting a formal examination.

5. Make certain that the patient is warmand comfortable during the examination.

6. Have the nursing staff record their obser-vations of any spontaneous movements of thepatient's extremities.

FIG. 5-13. Contraction of the gluteus maximus in-dicates integrity of S1 neurologic level.

Abbott, K.H., and Retter, R: Protrusions of tho-racic intervertebral disks, Neurology, 6: 1, 1955.

Abramson, A.S.: Bone disturbances in injuries tothe spinal cord and cauda equina, Bone JointSurg., 30-A: 982, 1948.

- - - : Principles of bracing in the rehabilitation ofthe paraplegic, Bull. Hosp. Joint Dis., X: 175,1949.

- - -: Changing concepts in the management ofspasticity, p. 205-228 in French, J.D. Ed. Con-ference in basic research in paraplegia, Thomas1962.

- - -: Modern concepts of management of the pa-tient with spinal cord injury, Arch. Phys. Med.Rehabil.,48: 113, 1967.

- - -: Advances in the management of theneurogenic bladder, Arch. Phys. Med., 52: 143,1971.

- - -: Management of the neurogenic bladder inperspective. Arch. Phys. Med. Rehabil., 57: 197,1976.

Abramson, A.S. and Delagi, E.F.: Influence ofweight bearing and muscle contraction on disuseosteoporosis, Arch. Phys. Med. Rehabil., 42:147, 1961.

Aegerter, E., Kirkpatrick, J.A. Jr.: OrthopaedicDiseases: Physiology, Pathology, Radiology, ed.3, Philadelphia, Saunders, 1968.

Alexander, M.A., Bunch, W.H. Ebbesson, S.O.Can experimental dorsal rhizotomy produce sco-liolis? J. Bone Joint Surg. 54: 1509-1513: 1972.

American Academy of Orthopaedic Surgeons:Symposium on Myelomeningocele, St. Louis,Mosby, 1972.

Apley, A.G.: Fractures of the spine, Ann. R. ColI.Surg., 46: 210, 1970.

- - -: A System of Orthopaedics and Fractures,ed. 4, London, Butterworth, 1973.

Arseni, C, and Nash, R.: Thoracic intervertebraldisc protrusion. J. Neurosurg., 17: 418, 1960.

Bailey, R.W., and Badgley, C.E.: Stabilization ofthe cervical spine by anterior fusion, J. BoneJoint Surg., 42A: 565, 1960.

Bannister, R.: Brain's Clinical Neurology, ed. 4,London, Oxford, 1973.

Barr, M.L.: The Human Nervous System: An Ana-tomical Viewpoint, ed. 2, Hagerstown, Harper &Row, 1974.

Basmajian, J.V.: Muscles Alive, ed. 3, Baltimore,Williams & Wilkins, 1974.

Index

Abduction, hip, 56shoulder, in tetraplegia, level C5,

80Abductors, finger, 23, 24, 25

shoulder, 8, 9Ache. See PainAchilles tendon reflex, 58, 65

herniated lumbar disc, 66,68-70herniated thoracic disc, 101memory aid, 63meningomyelocele, level L5-Sl,

115, 118spinal cord damage, levels L1-S1,

94-95testing, 61, 63,63

Adductor brevis, longus and mag-nus, 50

Adductors, meningomyelocele, levelU-L4,110

levelL4-L5,112level LS-Sl, 114

spinal cord lesions, levels L2-L4,94

Ambulation, meningomyelocele,113

spinal cord lesions, 84, 90prognostication, 98

See also WheelchairAnal wink, 64, 99,118Ankle, extension, 54, 55

flexion, 60Annulus fibrosus, cervical, 30

lumbar, 67Antebrachial cutaneous nerve, 23Arms, pain, and herniated disc, 29

and meningomyelocele, 119spinal cord lesion, level C6, 81

level C8, 83level Tl, 83-84

testing, memory aid, level C6, 17level C8, 23

neurologic level C5, 7-12,8-13neurologic levelC6, 13-17,13-

17neurologic level C7, 17-21,

18-21

Arms, testing-( Continued)neurologic level C8, 21-23,

22-23See also Extremity, upper

Atlas, cervical spine, 1Axillary nerve, 7-8, 8, 12,13

Babinski's sign, 95, 95Backache. See PainBeevor's sign, 45, 45, 93,100Biceps brachii, 10

testing, 11-12,12herniated disc, 32-36

spinal cord damage, level C5, 80level C6, 81

Biceps tendon reflex, 8herniated disc, 32-36testing, 12, 12, 13,27

memory aid, 12tetraplegia, 78-84spinal cord lesion, level C5, 80

level C6, 82level C7, 82

Bladder and bowel function, herni-ated thoracic disc, 101

meningomyelocele, levels L1-L2,L2-U,109

level U-L4, 111, 113level L4-L5, 113, 116level L5-S1, 115,118level Sl-S2, 117, 118level S2-S3, 118

spinal cord damage, levels Ll-S1,94-95

prognostication, 98-100Brachialis, 10Brachial-cutaneous nerve, sensation

test, 25Brachioradialis reflex, with herni-

ated discs, 32-36spinal cord damage, 82testing, 13,14,16,27tetraplegia, 78-84

Bulbocavernosus reflex, 99, 100

Carotid tuberosity, 7Cauda equina, 45, 93

and nerve roots, 66sacral sparing, 97, 97spinal cord lesions, 94-105

Cells, anterior horn, in poliomyeli-tis, 72,73

Cervical discs. See Disc, cervicalCervical nerves. See Nerve roots,

cervicalCervical spine. See Spine, cervicalCervical vertebrae. See VertebraeCompression fracture, of neck, 86,

87, 88Compression test, of osteoarthritis,

42,43Cord, spinal. See Spinal CordCremasteric reflex, 96, 96Crutch, arm muscle use, 19

spinal cord lesions, levels C3-T1,90-91

D.A.B., dorsal interossei, 23-25Deformity in meningomyelocele,

108level U-L4, 111level L4-L5, 113levelLS-Sl,117-118level S1-S2, 118level S2-S3, 118

Deltoid, with herniated discs, 32-36testing, 7-9, 8-9in tetraplegia, 78-84with spinal cord damage, 80

Dermatomes, definition, 1diagram, 2of feet, 65herpes zoster, 71of lower extremity, 49, 51level L4, 56level L4-S1, 68-70level L5, 59levels S2, 3, 4, 5,64of trunk, 94upper extremity, 27

Development milestones, 118-119

Diastomatomyelia, 119,119Disc, cervical, 1

herniated, 28-40, 28anatomic basis, 30cord damage, 91electromyogram, 37myelogram, 37neurologic levels, 32-36

table, 38tests for location, 31-37, 32-

36Valsal va test, 39

lumbar, herniated, 66-68,67-71myelogram, 71table, 66

thoracic, herniated, 100-101Dislocation, of spine, 102, 104

cervical, 85-90,88-90Distraction test, of osteoarthritis,

42,43Dorsal interossei (D.A.B.), testing,

23-25,24

Elbow, flexion and extension, 10-12,10-12

with spinal cord damage, levelC6,8l

Electromyogram, (EMG), herni-ated disc, 37

table, 38, 66Examination, meningomyelocele,

120See also Testing

Extension lag, of knee, 48, 49Extensor carpi radialis, 13, 14-15Extensor carpi ulnar is, 13, 14-15Extensor digiti minimi, 21Extensor digitorum, 20, 21

brevis, 55, 57, 59longus, 54, 55

meningomyelocele, level L5-Sl,114

testing, 57, 59, 74for herniated discs, 68-70

Extensor hallucis longus, 54, 55,74and herniated disc, table, 66testing, 57

Extensor indicis proprius, 21Extensors, toe, memory aid, 55Extremity, lower, nerve root lesions,

45-74upper, sensory summary, 27

neurologic levels, 28testing, scheme of, 25-28nerve root lesions, 7-43

See also Arms, Legs, Fingers,Toes, Hand, Foot, etc.

Facet joint, capsule, 101, 101dislocations, 88-90, 88-90

Femoral nerve, 47, 74Fingers, abduction, testing, 23-25,

23-25adduction, testing, 24, 25, 26extensors, 20,21

with herniated discs, 32-36with spinal cord damage, 82in tetraplegia, 78--84

flexors, 21muscle test, 21-23,20-23

with herniated disc, 32-36sensation testing, 21, 23in spinal cord lesion, 83

Flaccidity, of muscle, 97-98Flexor carpi radialis, 17, 20, 19Flexor carpi ulnaris, 17,19, 20Flexor digitorum, 21-23, 20, 22,

74Flexor hallucis, 74Foot, dermatome, 59, 63

dorsiflexion, 54, 55eversion, 58flail, 110

meningomyelocele, levels L 1-L2, L2-U, 109

level U-L4, 110, 111levelL4-L5,112,115level U-Sl, 114,118level 51-52, 116,118level S2-S3, 118

spinal cord damage, levels L4-51,94-95

tests, level L4, 51, 52, 53level L5, 54, 55, 57, 59levelSl,58, 59, 60, 61levels S2, S3, S4, 65

with herniated discs, 68-70inversion, 58plantarflexion,60

Forearm, sensation testing, 17,23Fractures, cervical spine, 85-88,

85-88

Gastrocnemius, 60, 61spinal cord lesions, level S1, 95

Gluteal nerve, testing, 61at neurologic table levels, 74

Gluteus maximus, 62testing, 61

in meningomyelocele, 116, 118,120-121,120-121

Gluteus medius, testing, 57, 59meningomyelocele, level L5-5l,

114and maximus, neurologic levels

affecting, table, 74spinal cord damage, level L4-

51,94-95Grading, of muscle, 2. See also

Muscle, grading

Hamstrings, neurologic levels affect-ing,74

with meningomyelocele, level L5-51,114

level 51-52,116testing, 120, 120

Hand, motor power, 26, 27with spinal cord lesion, 83See also Arm, Fingers

Hangman's fracture, 85, 86Heel, muscle testing, 57. See also,

FootHerpes zoster, 71-72Hip, abduction, 56

test, 59adductor muscles, neurologic lev-

els affecting, 74testing, 49,50,51

extension, 62flexion, 46-49, 46-49

neurologic levels affecting, 74with spinal cord damage, levels

Ll-L5,94-95function, with meningomyelocele,

levels Ll-L2 and L2-L3,109

levelU-L4, 110,111level L4-U, 112, 113levelU-Sl, 114,116-117level Sl-S2, 116, 118level 52-53, 118

Hoffmann's sign, 84,85Hydrocephalus, 119Hydromelia, 119Hyperextension, neck, 88,88Hyperflexion, neck, 87,88Hyperreflexia, 3Hyporeflexia, 3

Iliopsoas, function, with meningo-myelocele at level L3-L4,110

at level L4-U, 112atlevelL5-5l,114at level 51-52,116,118

with spinal cord damage, atlevels Ll-L3, 94

testing, 46-47, 46-47Infrapatellar tendon, reflex, 65Injuries, spinal, 102,103,104

spinal cord, 75Intercostal muscles, testing, 45Interossei dorsales, 23-25, 24

with herniated disc, 32-36in tetraplegia, 78--84

Interspinous ligament, 101, 101Intrinsic muscles, meningomyelo-

cele, 116, 118

Knee, extension lag, 48, 49function, with meningomyelo-

cele, 120atlevels Ll-L2, L2-L3, 109at level L3-L4, 110,111atlevel L4-LS, 112, 113at level LS-81, 114, 117at level 81-82, 116, 118at level 82-83, 118

with spinal cord damage, atlevels L4-81, 94-95

testing, 47, 48memory aid, 53patellar tendon reflex, 51,

52,53

Legs, function, with cord damage,levels Ll-81, 94-95

at neurologic levels L3-82, 65sensation dermatomes, L4 and

L5, 57,59and herniated disc, table, 66

testing scheme, 64-65, 65See also Extremities, lower

Levels, neurologic. See Neurologiclevel

Ligamentous complex, posterior,101

Ligamentumflavum, 101,101Longitudinal ligament, 30

lumbar, 67"Low back" pain. See PainLumbricals, 21-23, 23

Median nerve, 14, 17testing, 21-23

Memory aid, C5, biceps reflex, 12C6, sensory distribution, J 7C8, finger flexors, 23L4, patellar tendon reflex, 53,56L5, toe extensors, 55S1, Achilles tendon reflex, 81, 63

Meningomyelocele, 107-121developmental problems, 118-

119examination of patient, 120at level Ll-L2, 109at level L2-L3, 109at level L3-L4, 110, J11, 111,

113at level L4-L5, 112-113, 113,

115-116at level LS-81, 114-115, 116-

118at level 81-S2 and 52-83, J17,

118upper extremity, 119-120

Milestones, of development, 118-119

Motion range, chart, 2

Motor power, evaluation, 1Motor power tests, with herniated

discs, 32-36legs, 65in meningomyelocele, 108

in infants, 107at neurologic level, C2, with

spinal cord lesions, 78C3, with spinal cord lesion,

77-78,79C4, with spinal cord lesion, 79,

80C5, 7-12, 8

with spinal cord lesion, 80,81

C6, 13, 14with spinal cord lesion, 81

C7,18with spinal cord lesion, 82

C8,22with spinal cord lesion, 83

Tl,23-25,24with spinal cord lesion, 83-

84T2 to Tl2, 45

with spinal cord lesions, 93Tl2-L3, 47-49, 46-49Ll-81, with spinal cord dam-

age, 94-95L3-L4, with meningomyelo-

cele, 110, 111L4,51,52L4-L5, with meningomyelo-

cele, 112, 113, 115L4-SI, 68-70L5level, 54, 57, 57, 59L5-S1, with meningomyelo-

cele, 114,116-118Sllevel,58S1-S2, with meningomyelocele,

116,11852-S3, with meningomyelocele'

118upper extremity, 26, 27

Motor power. See also MuscleMotorcycles, and nerve root injury,

42,43Muscles, flaccidity and spasticity,

97-98grading, chart, 2

cervical, table, 38lumbar, table, 66thoracic, 100,100

myotomes,lin poliomyelitis, 72-73test, extensors of toe, 55

of foot, 64gastrocnemius-soleus, 61gluteus maximus, 61, 62gluteus medius, 59

Muscles, test-( Continued)of hip adductors, 51legs, scheme of, 64in meningomyelocele, 120-

121,120-121peroneus longus and brevis, 59,

61sacral sparing, 97, 97wrist extension, 16

of trunk and leg, neurologic levelaffecting, 74

Musculocutaneous nerve, la, 11,17

testing, 13of sensation, 17

Muscle. See specific muscles. Seealso Motor power

Myelitis, transverse, 91Myelogram, of herniated disc, cer-

vical,37table, 38

lumbar, 71table, 66

of meningomyelocele, 108Myotome, definition, 1

electromyogram of, 37

Neck, fractures, 85-88,85-88spinal cord injuries, 77-92

Nerves, trunk and leg, neurologiclevel affecting, 74

Nerve roots, avulsion of, 42, 43cervical, and herniated disc, 28,

32-36table, 38

lesions, 5-74level C5, 7-12C5 to Tl, 7-43T2 to 84, 45-74

lumbar, and herniated disc, 66,67,67

table, 66Neurologic level, in meningomyelo-

cele, determination, 107-118

C 1-T 1, clinical application, 28-43

C2, spinal cord lesion, 78C3, spinal cord lesion, 77-78, 79C4, spinal cord lesion, 78-80, 80C5, herniated disc, 32

nerve root testing, 7-12, 8-12spinal cord lesion, 80,81

C6, herniated disc, 33nerve root testing, 13-17, 14spinal cord lesion, 81-82, 82

C7, herniated disc, 34nerve root testing, 17-21,18spinal cord lesion, 82, 83

Neurologic level-(Continued)C8, herniated disc, 35

nerve root testing, 21-23, 22spinal cord lesion, 83,84nerve root testing, 23-27,24spinal cord lesions, 83, 84

Tl, herniated disc, 36T 1-T12, spinal cord lesions, 93Tl-52, spinal cord lesions, am-

bulation,98bladder and bowel control,

98-100T2 to T12, testing, 45Tl2-L3, testing, 47-51Ll-S 1,spinal cord damage, 94-95Ll-S4, related to muscles and

nerves, 74LI-L2, meningomyelocele, 109L2-L3, meningomyelocele, 109L3-L4, meningomyelocele, 110-

111,111,113L3-S1, and poliomyelitis, 73L4, disc L3-L4, tests, 68

testing, 51-53,56-57,52L4-L5, meningomyelocele, 112-

113,113,115-116L4-S1, clinical application, 68-74L4-S I, testing, and back pain, 67L5,54,55,56,57,59

disc L4-L5, tests, 69L5-S1, meningomyelocele, 114-

115,116-118S1, testing, 58,61-64

disc L5-Sl, tests, 70S1-52, meningomyelocele, 116-

117, 118S2,3,4,64-65S2-S3, meningomyelocele, 118and spinal cord, 75-121upper extremity, 28

Obturator nerve, 49neurologic level affecting, 74

Odontoid process, 7fracture, 86,86-87

Oppenheim's sign, 95, 96Osteoarthiritis, cervical spine, table,

38tests, 42,43of uncinate process, 40-42, 41,

43

P.AD., palmar interossei, 25Pain, back, teen-age, 71

"low back," 67-68from herniated disc, 29, 31,31herpes zoster, 71of neck, whiplash, 39-40in osteoarthritis, 42-43,43sensation of, 1-2

Pain-(Continued)in spondylolysis, 70

Palmar interossei (P.A.D.) testing,25

Paraplegia, 83-85, 93-96ambulation prognostication, 98bladder and bowel control, 98-

100Pars interarticularis, 72

and spondylolysis, 69Patellar tendon reflex, 52

with herniated lumbar disc, 66,68-70

with herniated thoracic disc, 101at L-4 level, 65memory aid, 53with meningomyelocele, Ill, 113with spinal cord damage, 94-95

Perineum, level affecting, 74Peroneal nerves, testing, 51, 57, 59,

61neurologic levels affecting, 74

Peroneus longus and brevis, 58, 59and herniated discs, 66,68-70neurologic levels affecting, 65, 74testing, 61

Plantar nerves, 74Poliomyelitis, 72-73Processes, of vertebra, 40

Quadriceps, 53with meningomyelocele, L3-L4,

110level L4-LS, 112leveILS-Sl,114level SI-S2, 116

neurologic levels affecting, 65,74with spinal cord lesions, levels

L2-LS,94-95testing, 47-49, 49

Quadriplegia. See Tetraplegia

Radial extensors, 13Radial nerve, 10, 14, 20, 21

testing, 17, 20Radiation, of pain. See PainRectus abdominus, testing, 45Rectus femoris, 48Reflexes, anal function, 99-100, 100

cremasteric, 96, 96with herniated cervical discs, 32-

36table, 38

with herniated lumbar discs, 68-70

table, 66with herniated thoracic discs,

100-101

Reflexes-( Continued)with meningomyelocele, levels

Ll-L2, L2-L3, 109level L3-L4, 111, Ill, 113level L4-LS, 113, 116levelLS-51, 115,118level 51-52, 117,118level S2-S3, 118

with spinal cord lesion, level C3,78,79

level C4, 79-80, 80level C5, 80-81,81level C6, 82, 82level C7, 82,83level C8, 83, 84level Tl, 84levels L I-S 1, 94-96, 95-96

stretch are, 2-3testing, level C5, biceps tendon,

8, 12,32level C6, brachioradialis, 13,

14, 16, 33level C7, triceps, 18, 21, 21, 34level C8, none, 22, 35level Tl, none, 24, 36level L4, patellar tendon, 49,

51, 52, 53, 53, 56level L5, none, 54, 59level Sl, Achilles tendon, 58,

61,63-64,63levels, S2, S3, S4, 64,64lower extremity, 65sacral sparing, 97, 97upper extremity, 27

in tetraplegia, 84, 78-84Respiration, with spinal cord le-

sions, 78, 78, 79, 79, 80,81, 90

Roentgenography, of spine injury,101, 102,104

Roots, of nerves. See Nerve root

Sacral sparing, 97-98, 97bladder and bowel control, 99in meningomyelocele, 109

Sciatic nerves, 74Scoliosis, 119Scotty dog, lumbar spine, 72Segments, of spinal cord, 1Sensation, evaluation methods, 1-2

with meningomyelocele, level SI-S2, 117, 118

levels Ll-L2, L2-L3, 109level L3-L4, 111, 111levelL4-LS, 113,115-116level LS-Sl, 115, 118level S2-S3, 118

with spinal cord damage, levelC5,80

Sensation, with spinal cord damage-( Continued)

level C4, 79, 80level C3, 78level Tl, 84level C8, 83level C7, 82level C6, 81-82levels Tl-Tl2, 93, 94levels Ll-Sl, 94-95

in tetraplegia, 78-84testing, arm, 17,23,25,27,27

herniated cervical discs, 32-36,38

table, 66herniated thoracic disc, 100legs, scheme of, 64-65level C5, axillary nerve, 8, 12,

13, 32level C6, musculocutaneous

nerve, 14,17,17,33level C7, 18, 21,34level C8, antebrachial cutane-

ousnerve,22, 23,35level T1, brachial-cutaneous

nerve, 24, 25,36levels T2 to T12, 45, 94levels Tl2-L3, 49, 50, 5 J, 51level L4, 52,56-57level L4-S1, 68-70level L5, 54, 59level SI, 58, 64levels S2, S3, S4, S5, 64sacral sparing, 97, 97See also Dermatome

Serratus anterior, testing, 9Shingles, 71-72Shock, spinal, 97-98Shoulder, abduction, 7-9, 8-9

spinal cord damage, level C5, 80level C6, 81

Sitting, development, 118Skin, dermatomes, 1Soleus, 60, 61

spinal cord lesions, level SI,95

Spasticity, of muscles, 97-98Spinal cord, bifid, 119

lesions, 75-121cervical, 77-92

level C2, 78level C3, 77-78,79level C4, 79-80, 80level C5, 80-81,81level C-6, 81-82,82level C7, 82-83,83level C8, 83, 84

clinical application, 96-101complete or incomplete, 96-

97,99-100

Spinal cord, lesions-( Continued)lumbar, level Ll, L2, L3, 94

level L4, 94-95level L5, SI, 95

thoracic, level Tl, 83-84levels Tl-TI2, 93-105

protection following, 101-102,104-105

in poliomyelitis, 72, 73segments of, 1

Spinalshock,97-98after trauma, 77

Spine, cervical, articulation, 29fractures, 85-88,85-88sprain, 39-40tests for osteoarthritis, 42, 43

fusion, 102injury, compression, 104, 105

flexion, 102, 103, 104flexion-rotation, 102, 103, 104,

105hyperextension, 104, 105

stability after injury, 101-105criteria for, cervical section,

102thoracolumbar and lumbar

sections, 105thoracic and lumbar, 99

Spinothalamic tracts, 1-2, 2Spinous process, of vertebra, 40Spondylolysis, 68-71,72Spondylolysthesis, 68-71Sprain, cervical neck, 39-40Stability of spine, 101-105Standing, development, 118-119Stretch reflex. See Reflex, stretchSuprascapular nerve, 8-9,8Supraspinous ligament, 101, 101Supraspinatus, testing, 9Syringomyelia, 120

Temperature, sensation of, 1-2Test, Valsalva, cervical discs, 39

distraction, of osteoarthritis, 42,43

See also Muscle testing, Sensorytesting, Reflex testing

Testing, in meningomyelocele, 120-121,120-121

Tetraplegia, 77-92level C2, 78level C3, 79

Tibial nerves, levels affecting, 74Tibialis anterior, testing,S!, 52, 53,

65for herniated discs, 68-70

table, 66with meningomyelocele, level L4-

LS, 112,115level LS-Sl, 114

Tibialis anterior-(Continued)with spinal cord lesions, levels,

L4-LS,94-95and posterior, 74

Toes, clawed, 64extensors, memory aid, 55

at neurologic levels, 65testing, 57, 59

intrinsic muscles, 74with spinal cord damage, 95tests of, 55

Touch, sensation of, 2Transverse foramen, 7Transverse process, cervical spine, 7Triceps, tendon reflex, 18, 21, 21,

27herniated disc, 32-36spinal cord damage, 82in tetraplegia, 78-84

testing, 17-18Trunk, nerve root lesions, 45-74Tuberculosis, cervical spine, 91Tumors, cervical spine, 91

Ulnar extensors, 13Ulnar nerve, 14, 17,20

testing, 21-25, 24Uncinate process, and herniated

discs, table, 38and osteoarthritis, 40, 40-42

Valsalva test, 39Vastus lateralis, 48Vastus medialis, 48-49Vertebrae, cervical, 28

anatomy of, 40fracture, 85-88,85-88

facet joint dislocation, 88-90,88-90

lumbar, 67-70, 72slippage of, 68-69thoracic and lumbar, 99See also Spine

Walking, development, 119Wheelchair, spinal cord lesions, 80,

81,82,84,90See also Ambulation

Whiplash injury, 39-40, 39Wink, anal, reflex. See Anal reflexWrist, extension, test, C6, 14

extensors, testing, 13-17, 14-16herniated disc, 32-36

spinal cord damage, 81and flexors, in tetraplegia, 78-

84flexion test, 18, 20flexors, 17-21,19,20

with herniated disc, 32-36with spinal cord damage, 82