Lateral Perspective of the Posterior Antebrachial Cutaneous Nerve

Description

Running superficially along the posterolateral forearm, the posterior antebrachial cutaneous nerve is traced from its origin as a branch of the radial nerve in the distal arm, emerging between the lateral head of triceps brachii and brachioradialis near the lateral epicondyle. From there it descends distal to the elbow on the posterior compartment, coursing over extensor carpi radialis longus and brevis and toward the dorsolateral wrist, where it supplies skin over the posterior forearm. Biceps brachii, brachialis, and triceps brachii frame the proximal course, with the radius and ulna providing bony landmarks at the elbow and along the forearm. The path is long and winding. A lateral perspective matters because this cutaneous branch sits directly in the corridor used for common lateral elbow exposures and for superficial injections and incisions around the lateral epicondyle. Traction or iatrogenic injury can present as dysesthesia over the posterior forearm, and the nerve’s relationship to the radial nerve proper helps distinguish a purely sensory deficit from a proximal radial neuropathy that would also affect wrist and finger extension. The illustration also supports teaching of radial nerve branching in the arm, where the posterior antebrachial cutaneous nerve typically arises proximal to the division into superficial and deep (posterior interosseous) branches. Use this artwork in upper limb anatomy and neuroanatomy courses to reinforce cutaneous innervation territories and to orient learners to lateral elbow landmarks, including the lateral epicondyle and the muscle plane between brachioradialis and triceps. It also suits clinical teaching files for lateral epicondylitis workups, radial tunnel syndrome differentials, and operative notes where documenting protection of the posterior antebrachial cutaneous nerve reduces postoperative sensory complaints. Anatomical accuracy verified by SciePro's Medical Advisory Board.