Anterior interosseous nerve

The anterior interosseous nerve (volar interosseous nerve) is a branch of the median nerve that supplies the deep muscles on the front of the forearm, except the ulnar half of the flexor digitorum profundus.

It accompanies the anterior interosseous artery along the front of the interosseous membrane of the forearm, in the interval between the flexor pollicis longus and flexor digitorum profundus, supplying the whole of the former and the radial half of the latter, and ending below in the pronator quadratus and wrist joint.

Many texts, for simplicity's sake, consider this nerve part of the median nerve.

Innervation
The anterior interosseous nerve innervates 2.5 muscles:
 * flexor pollicis longus
 * pronator quadratus
 * the radial (lateral) half of flexor digitorum profundus

These muscles are in the deep level of the anterior compartment of the forearm.