To: jpmac who wrote (43825 ) 12/22/1999 6:42:00 PM From: Ilaine Read Replies (1) | Respond to of 71178
Quick anatomy lesson from "The Adult Spine - Principles and Practice," 2d. ed., Volume 1, pages 1328-1329: "The C5 root involves the shoulder (deltoid muscle - shoulder abduction). The C6 root primarily supplies the elbow flexors (biceps and brachialis muscles) and the wrist extensors (extensor carpi radialis longus and brevis and extensor carpi ulnaris muscles). The C7 root is basically the antagonist of the C6 root (elbow extension - triceps muscle, wrist flexion - flexor carpi radialis and flexor carpi ulnaris muscles), with with addition of finger extension at the metacarpal phalange (MP) joints. The C8 and T1 roots primarily supply the hand extrinsic muscles, with the C8 roots primarily responsible for flexion at the MP joints and the T1 roots supplying the abductors and adductors of the fingers." (Snip) "The cervical nerve roots exist above the corresponding vertebral body. For example, the C5 root exists above the C5 vertebral body. Therefore, a disc rupture of the C4-C5 intervertebral body will usually compress the C5 root. Because the C8 root comes out above the T1 body, the relationship of the nerve root to the disc space is different below the cervical-thoracic junction. As previously noted, patients with cervical radiculopathy have a predominance of proximal pain and distal parethesias. Therefore, a patient with cervical degeneration at C5-C6 with compression of the C6 root tends to have pain down the lateral arm, with paresthesias in the lateral forearm down to the thumb. In addition, the patient may have weakness of the elbow flexors and wrist extensors with hyporeflexia of the biceps and/or brachioradialis reflexes." One thing to keep in mind is that, while the nerves from one nerve root generally innervate a specified part of the body, this does vary somewhat from person to person. If you take the above passage, and compare it with an anatomical representation of the muscles of the body, it should make perfect sense. The MP joints of the hand are the ones between the fingers and the hand.