The anterior interosseous nerve is a branch of the median nerve in the forearm.
It is purely motor and supplies:
- flexor digitorum profundus - flexes distal phalanges of index and middle fingers
- flexor pollicus longus - flexes thumb
- pronator quadratus muscle - pronates hand
Damage may occur without any obvious cause or may develop as a result of external pressure on the forearm or from gripping tightly in association with pronation.
Recovery usually occurs spontaneously over 2 - 3 months. Exploration is indicated if the injury persists.