The flexor digitorum superficialis is a large, wide muscle that lies partially deep and partially superficial on the forearm. It originates from all three arm bones: the |humerus|, the |ulna|, and the |radius|. The muscle extends down the arm narrowing into a ~tendon~ that inserts in the palmar side of the |phalanges| of the index, middle, ring, and little fingers. It does not have an attachment to the thumb. This muscle is used to bend the fingers.
