Origin: Medial epicondyle of the humerus (common flexor tendon)
Artery: Ulnar artery
Nerve: Muscular branches of ulnar nerve
Action: Flexion and adduction of wrist
Antagonist: Extensor carpi ulnaris muscle
The Flexor carpi ulnaris lies along the ulnar side of the forearm. It arises by two heads, humeral and ulnar, connected by a tendinous arch, beneath which the ulnar nerve and posterior ulnar recurrent artery pass. The humeral head arises from the medial epicondyle of the humerus by the common tendon; the ulnar head arises from the medial margin of the olecranon and from the upper two-thirds of the dorsal border of the ulna by an aponeurosis, common to it and the Extensor carpi ulnaris and Flexor digitorum profundus; and from the intermuscular septum between it and the Flexor digitorum sublimis. The fibers end in a tendon, which occupies the anterior part of the lower half of the muscle and isinserted into the pisiform bone, and is prolonged from this to the hamate and fifth metacarpal bones by the pisohamate and pisometacarpal ligaments; it is also attached by a few fibers to the transverse carpal ligament. The ulnar vessels and nerve lie on the lateral side of the tendon of this muscle, in the lower two-thirds of the forearm.
Variations.—Slips of origin from the coronoid. The Epitrochleo-anconaeus, a small muscle often present runs from the back of the inner condyle to the olecranon, over the ulnar nerve.