Anatomy

Origin

Upper three-fourths of anterior and medial surfaces of shaft of ulna and medial side of the coronoid process, interosseous membrane.

Insertion

Front of base of distal phalanges of second to fifth finger.

Nerve

Ulnar nerve supplies the medial half of the muscle (going to the fourth and fifth fingers). Anterior interosseous branch of median nerve supplies lateral half (going to index and middle fingers) (C8, T1).

Actions

Flexes distal phalanges.