Review Note

The deep branch of the ulnar nerve is the specific branch of the ulnar nerve that innervates the intrinsic muscles of the hand, with the exception of the thenar compartment and the radial two lumbrical muscles. This includes the interossei, which abduct and adduct the fingers. The median nerve innervates most of the muscles in the anterior compartment of the forearm, with the exception of half of flexor digitorum profundus and flexor carpi ulnaris. Both of these muscles are innervated by the ulnar nerve. The recurrent motor branch of the median nerve innervates the thenar compartment of the hand, including abductor pollicis brevis, flexor pollicis brevis, and opponens pollicis. Finally, the superficial branch of the ulnar nerve provides sensory innervation to the skin on the medial side of the wrist and hand and the medial 1.5 digits on the palmar side of the hand.