Anatomy, Shoulder and Upper Limb, Radial Nerve

Excerpt

The radial nerve is a peripheral nerve supplying specific parts of the arm, forearm, wrist, and hand (see Image. Posterior Upper Extremity Nerves). This nerve has both motor and sensory functions. The motor branches stimulate the posterior arm muscles, posterior forearm muscles, and extrinsic wrist and hand extensors. The sensory branches supply the skin on the anterolateral arm, distal posterior arm, posterior forearm, and posterolateral wrist and hand areas. The radial nerve's distribution diminishes lateromedially from the thumb to the ring finger. The median nerve innervates the digit pads of the lateral 3-1/2 fingers, while the ulnar nerve supplies the medial 1-1/2 digit pads.

The radial nerve originates from the ventral rami of the spinal nerves C5 to T1 and is part of the posterior cord of the brachial plexus. Radial nerve disruption can lead to neurologic deficits in its area of distribution.