REIDER PART 260

320 Chapter 8 Cervical and Thoracic Spine

To test the wrist extensors, the examiner asks the patient to flex the involved elbow and extend the wrist while the arm is held tightly at the side. The examiner sta-bilizes thepatients forearm with one hand while exerting downward pressure on the dorsiflexed wrist (sec Fig. 8-32B). In most normal patients, the examiner is not able to overcome the patients wrist extensor strength. Because the C5-C6 disk is the cervical disk most com-monly involved in herniation or degeneration, a C6 radiculopathy is the most likely to be encountered.

C7 Nerve Root. The C7 nerve root, which exits the spine through the C6-C7 neuroforamen, is most easily assessed by testing the wrist flexors. The position is very close to that used for the assessment of wrist extensor strength. In this case, however, the patient is asked to make a Fist and flex the wrist as strongly as possible while the examiner attempts to overcome the patient s strength and force the wrist into extension (Fig. 8-33A). Normally, the examiner can overcome the patients flcxion strength only with considerable difficulty.

The C7 nerve root may also be assessed by testing the strength of the long finger extensors. In this test, the examiner asks the patient to extend the Fingers fully with the wrist in the neutral position. The examiner then sta-bilizes the patient s wrist with one hand and attempts to passively flex the patients metacarpophalangeal joints while the patient resists maximally (see Fig. 8-33B). The examiner should be able to flex the fingers only with difficulty.

C7 also innervates the triceps brachii. To test triceps strength, the examiner grasps the patient s wrist and gen-tly flexes the patient’s elbow. The examiner’s other hand stabilizes the patients upper arm. The patient is then asked to extend the elbow as strongly as possible (see Fig. 8-33C). Normally, the examiner is unable to over-come the patient s triceps strength, and a strong patient may push the examiner away. Alternatively, the patient can be asked to hołd the elbow in fuli extension while the examiner attempts to flex it. The examiner is not normally able to overcome the patient and flex the elbow.

C8 Nerve Root The C8 nerve root, which exits the spine through the C7-T1 neuroforamen, is best assessed by testing the long digital flexors and, thus, the patients grip. One method of assessing the grip is to place the

Figurę 8-33. Assessing C7 motor function. A, Wrist flexors. B, Long finger extensors. C, Triceps brachii.