Motor Innervation of Anterior Interosseous Nerve Motor flexor digitorum profundus - radial half flexor pollicis longus pronator quadratus Sensory none Reflex none Origin & Branches C5-T1 roots medial and lateral cord of brachial plexus median nerve AIN branch to FDP branch to FPL branch to pronator quadratus Course Branch from median nerve branches from median nerve 4cm distal to medial epicondyle it runs along the front of the interosseous membrane of the forearm in the interval between the flexor pollicis longus and flexor digitorum profundus it terminates distally in the pronator quadratus and wrist joint. Clinical Conditions Anterior interosseous syndrome Pediatric supracondylar fractures