The objective measures where efficiency, absolute strength and weight of the flexor carpi ulnaris muscle.

The median nerve emerges to lie between the flexor digitorum superficialis and the flexor carpi ulnaris muscles which are just above the wrist.

Flexor carpi ulnaris muscle arises by two heads - humeral and ulnar, connected by a tendinous arch beneath which the ulnar nerve and ulnar artery pass.

There it supplies one and a half muscles (flexor carpi ulnaris and the medial half of flexor digitorum profundus) and courses with the ulnar artery, travelling inferiorly with it deep to the flexor carpi ulnaris muscle.

It innervates the flexor carpi ulnaris muscle, the flexor digitorum profundus muscle to the ring and pinky fingers, and the intrinsic muscles of the hand (the interosseous muscle, the lumbrical muscles and the flexor pollicus brevis muscle).

The anterior interosseous branch courses with the anterior interosseous artery and innervates all the muscles of the deep group of the anterior compartment of the forearm except the medial (ulnar) half of flexor digitorum profundus and flexor carpi ulnaris muscle.

(Attempt to salvage a floating thumb include transferring the flexor carpi ulnaris muscle as a thumb flexor, and making a thumb metacarpal out of a metatarsal bone taken from a foot; but this leaves an inadequate thumb, and a wrist weakness, and foot damage.)