Extensor digiti minimi m

One of the extensor muscles of the forearm, the EDM originates from the lateral epicondyle of the humerus and inserts into the proximal phalanx of digit 5.  Its main action is to extend the pinky, but since it crosses the wrist it will also have some small contribution to wrist extension.  Its innervation is the same as all extensor muscles of the arm and forearm, the radial n.