Opponens pollicis muscle
Opponens pollicis muscle |
---|
origin |
Flexor retinaculum and trapezium |
approach |
Lateral side of the first metacarpal |
function |
Rotation of the thumb towards the palm of the hand |
Innervation |
Median nerve |
Spinal segments |
C6-C8 |
The opponens pollicis muscle ( Latin for "counterpart of the thumb") is one of the muscles of the metacarpal in the area of the ball of the thumb . For pets the muscle does not occur.
function
The opponens pollicis muscle, located very laterally on the ball of the thumb ( thenar ), turns the thumb towards the palm of the hand and thus places it opposite the remaining fingers (so-called opposition ). This turns the human hand (in interaction with the medially adjacent flexor pollicis brevis muscle ) into a gripping hand.
This is also made possible by the special anatomy of the thumb (pollex). The proximal articulatio carpometacarpale functions here as a saddle joint with two-dimensional freedom of movement. The thumb is shorter than the other phalanx and has only two free-standing bone elements due to the two basic joints (see wrist ).