Superficial Radial Nerve

ramus superficialis nervi radialis

The superficial branch of the radial nerve is the pure sensory continuation of the radial nerve after it gives off the deep (posterior interosseous) branch at the elbow. It descends under the brachioradialis muscle along the lateral forearm and emerges subcutaneously 8-10 cm above the wrist by passing deep to the brachioradialis tendon. It supplies the dorsal skin of the radial hand, the dorsal thumb, and the dorsal proximal two phalanges of the index and middle fingers.

Region: Forearm

Clinical Relevance

Clinical Notes

The superficial radial nerve is the most commonly injured nerve at the wrist. Handcuff neuropathy results from prolonged external pressure over the nerve as it becomes subcutaneous on the radial dorsal wrist. De Quervain tenosynovitis procedures and radial wrist incisions risk the nerve's cutaneous branches. Wartenberg syndrome (superficial radial nerve entrapment between brachioradialis and ECRL at the mid-forearm) produces dorsal radial hand and thumb numbness reproduced by forearm pronation. Treatment is decompression of the nerve at the fascial edge.

Pathology

Common Injuries & Conditions

Wartenberg Syndrome

Superficial radial nerve entrapment between the brachioradialis and extensor carpi radialis longus tendons in the mid-forearm produces dorsal radial hand numbness and Tinel sign at the entrapment site, worsened by forearm pronation; managed by decompression of the fascial edge between the two tendons through a forearm incision.

Handcuff Neuropathy

Tight handcuffs or external wrist pressure over the superficial radial nerve as it becomes subcutaneous at the radial wrist produce neuropraxia with dorsal radial hand numbness, typically recovering spontaneously within weeks.