There are two major muscles located in the forearm that flex the fingers. They are the flexor digitorum superficialis and the flexor digitorum profundus. The flexor digitorum profundus is located just beneath the flexor superficialis.

Origin

It originates on the upper anterior and medial surfaces of the ulna.

Insertion

Insertion is by four tendons, which separate after passing the wrist and then go to the fingers.

Function

Flexes the fingers.