Dorsal Digital Branches of Radial Nerve

Origin

The superficial terminal branch of the radial nerve divides into four dorsal digital branches upon reaching the dorsum of the hand (C6—C8 spinal segments).

Course

In the lower one third of the forearm, the superficial terminal branch of the radial nerve passes backwards underneath the tendon of brachioradialis muscle. As it winds around the radial bone, it pierces the deep fascia to reach the dorsum of the hand. It provides cutaneous innervation to the skin of the dorsum of the hand and divides into four dorsal digital branches to further supply the skin of the digits.

Branches

Sensory nerve fibers from the skin of the dorsum of the hand and digits ascend through the superficial terminal branch and the dorsal digital branches of the radial nerve to eventually convey the information into the C6—C8 cervical spinal segments.

Supplied Structures

The dorsal digital branches provide sensory cutaneous innervation to the skin of the digits (except for the terminal portions supplied by the median nerve) as follows:

—first dorsal digital nerve innervates the lateral side of the thumb;

—second dorsal digital nerve innervates the medial side of the thumb;

—third dorsal digital nerve innervates the lateral side of the index finger;

—fourth dorsal digital nerve innervates contagious sides of index and middle fingers;

—fifth dorsal digital nerve, when present, innervates contagious sides of the middle and ring fingers.