Nerves of the forearm: Posterior view (English)

The radial nerve divides into superficial and deep branches just anterior to the lateral epicondyle of the humerus. The superficial branch descends along the anterior forearm curving around the radius between the brachioradialis and pronator teres muscles to enter the posterior distal third of the forearm. The deep branch of the radial nerve exits the cubital fossa and enters the posterior forearm by passing between the humeral and ulnar heads of the supinator muscle. At this point it becomes known as the posterior interosseous nerve. This nerve provides motor innervation to muscles of the posterior forearm. The posterior antebrachial cutaneous nerve arises from radial nerve in the posterior compartment of the arm and descends distally to provide cutaneous innervation to the skin of the posterolateral forearm. Posterior branches of the medial and lateral antebrachial nerves also contribute to the cutaneous innervation of the posterior forearm.