The flexor digitorum profundus is a third-layer muscle of the forearm, which lies on its anterior aspect, along the ulnar side. With a flat and wide belly, it springs from the proximal half of the anterior ulnar surface and the interosseous membrane. Then it runs downwards, ending up in four strong tendons, which travel under the flexor retinaculum and through the carpal tunnel. These tendons are inserted into the base of the distal phalanges of all four fingers.
Action
The flexor digitorum profundus muscle flexes the distal phalanges of all fingers, except the thumb.
Innervation
It is supplied by the median and ulnar nerve (C6-C8-T1).
Blood Supply
The flexor digitorum profundus receives oxygenated blood from secondary branches of ulnar artery.
Below, the third layer muscles of forearm, which include the flexor pollicis longus and the flexor digitorum profundus.
