Posterior interosseous nerve

Structure

Course

It descends along the interosseous membrane, anterior to the extensor pollicis longus muscle, to the back of the carpus, where it presents a gangliform enlargement from which filaments are distributed to the ligaments and articulations of the carpus.

Supply

The posterior interosseous nerve supplies all the muscles of the posterior compartment of the forearm, except anconeus muscle, brachioradialis muscle, and extensor carpi radialis longus muscle. In other words, it supplies the following muscles:

• Extensor carpi radialis brevis muscle — deep branch of radial nerve
• Extensor digitorum muscle
• Extensor digiti minimi muscle
• Extensor carpi ulnaris muscle
• Supinator muscle — deep branch of radial nerve
• Abductor pollicis longus muscle
• Extensor pollicis brevis muscle
• Extensor pollicis longus muscle
• Extensor indicis muscle

The posterior interosseous nerve provides proprioception to the joint capsule of the distal radioulnar articulation, but not pain sensation.