Superficial radial nerve

The superficial radial nerve, also known as the superficial branch of the radial nerve, is a sensory cutaneous nerve that arises from the radial nerve. It supplies the skin on the dorsum of the hand as well as providing articular branches to joints in the hand.

Gross anatomy

Origin

As a branch of the radial nerve the superficial radial nerve receives fibers from all roots of the brachial plexus (C5-T1). It branches under the proximal tendon of the brachioradialis muscle in the upper to middle third of the forearm.

Course

The superficial branch of the radial nerve travels in the posterior compartment of the forearm descending in a plane between the pronator teres and brachioradialis muscles. The nerve emerges from beneath the brachioradialis muscle to arborise over the roof of the anatomical snuffbox providing a medial and lateral terminal branch.

Branches and supply

• the medial branch is the larger of the terminal branches of the superficial radial nerve and innervates the ulnar aspect of the dorsum of the thumb, the dorsum of the index and middle fingers and the radial aspect of the fourth finger; note that this excludes supply to the subungual region which is supplied by the palmar cutaneous branch of the median nerve  
• the lateral branch of the superficial radial nerve provides sensation to the radial aspect of the thumb as well as the dorsal surface of the base of the thumb

Relations

The superficial radial nerve is lateral to the radial artery in the forearm.