It accompanies the anterior interosseous artery along the anterior 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 (most commonly) the radial half of the latter, and ending below in the pronator quadratus and wrist joint.
A branch of the median nerve, the anterior interosseous nerve (AIN) can be affected by either direct penetrating injury, possibly compression in a fashion similar to carpal tunnel syndrome, but most commonly an idiopathic inflammatory process (referred to an Anterior Interosseous Syndrome).
Non-surgical treatment consists of splinting, proximal tissue massage and anti-inflammatory drugs.
Pronator Syndrome is similar, but involves both the AIN as well as the median nerve proper.
[1] This article incorporates text in the public domain from page 938 of the 20th edition of Gray's Anatomy (1918)