The flexor carpi ulnaris muscle is an extrinsic muscle of the hand found on the ulnar side of the forearm. It arises from the medial epicondyle, medial olecranon, and proximal ulnar head at the elbow to insert on several of the carpal bones. It serves to flex the wrist (move it toward the anterior forearm) and adduct the wrist. Generally, a flexor muscle is one that decreases the angle between two bones, as in bending the arm at the elbow; raising the leg toward the stomach as in kicking a football; or bringing the lower leg up toward the thigh. Another flexor muscle will bring the thumb across the palm of the hand.