The radial nerve divides into a superficial (sensory) and deep (motor) branch at the cubital fossa. The deep branch of the radial nerve winds to the back of the

forearm The forearm is the region of the upper limb between the elbow and the wrist. The term forearm is used in anatomy to distinguish it from the arm, a word which is most often used to describe the entire appendage of the upper limb, but which in ...

around the lateral side of the radius between the two planes of fibers of the Supinator, and is prolonged downward between the superficial and deep layers of muscles, to the middle of the forearm. The deep branch provides motor function to the muscles in the posterior compartment of the forearm, which is mostly the extensor muscles of the hand. The radial nerve arises from the posterior cord of the brachial plexus. The posterior cord takes nerves from the upper, lower, and middle trunk, so ultimately the radial nerve is formed from the anterior rami of C5 through T1. The radial nerve passes through the axilla, which makes it susceptible to injury. It can be compressed against the humerus by crutches, causing crutch paralysis. Symptoms of damage to the deep branch of the radial nerve typically include "wrist drop", which is the flexion of fingers, hand, and wrist, since the extensor muscles supplied by the nerve are paralyzed. Normal sensation of the skin is retained, since this nerve only provides sensory function to ligaments and articulations of the carpal and metacarpal joints. Since the nerve passes dorsally around the head of the radius, it is susceptible to traction or compression injuries when the elbow joint is injured, in particular, radial dislocation. Another area of potential entrapment is the arcade of Frohse, a fibrous arch formed from the proximal part of the superficial head of the supinator, under which the deep branch of the radial nerve passes. The passage for the nerve varies in size. In some cases of spontaneous paralysis of the nerve, releasing this fibrous band released pressure on the nerve and restored function Considerably diminished in size, it descends as the

posterior interosseous nerve The posterior interosseous nerve (or dorsal interosseous nerve) is a nerve in the forearm. It is the continuation of the deep branch of the radial nerve, after this has crossed the supinator muscle. It is considerably diminished in size compared t ...

. For some authors, the deep branch of the radial nerve is the same as the

Additional images

File:Gray417_color.PNG, Cross-section through the middle of the forearm. File:Gray420.png, The Supinator. File:Gray817.png, Deep palmar nerves.

References

External links

* {{Authority control Nerves of the upper limb