Flexor digitorum profundus muscle

The flexor digitorum profundus muscle is a muscle in the forearm that flexes (curls inward) the fingers.

Action
The flexor digitorum profundus affects different parts of the hand depending on the degree of its contraction. If contracted weakly, it flexes only the distal interphalangeal joints. Stronger contraction will also flex the proximal interphalangeal and metacarpophalangeal joints and the wrist.

Origin
The flexor digitorum profundus originates from the elbow, on the ulna at the medial olecranon process.

Insertion
The flexor digitorum profundus inserts in each of the four fingers, on the distal phalanges.

Innervation
The flexor digitorum profundus is innervated by the median nerve and the ulnar nerve.