above the wrist, passes beneath the tendon of the Brachioradialis, and, piercing the deep fascia, divides into two branches: lateral and medial.

The lateral branch, the smaller, supplies the radial side of the thumb (by a digital nerve), the skin of the radial side and ball of the thumb, joining with the volar branch of the lateral antebrachial cutaneous nerve.

The superficial branch of radial nerve is associated with an entrapment neuropathy called Wartenberg's syndrome.

The nerve may be compressed due to wearing a tight wristband, watch or bracelet.

[1] This article incorporates text in the public domain from page 944 of the 20th edition of Gray's Anatomy (1918)