Supinator muscle

The supinator muscle (Latin for " Away Dreher " ) is one of the deep skeletal muscles of the forearm. It originates in man the only muscle of this layer on the upper arm bone. The deep branch ( ramus profundus ) of the radial nerve pierced him.

In the ungulates of the muscle is not formed or only rudimentary ( pigs). A rotation of the radius around the ulna is in these due to the coalescence impossible anyway.

Function

The musculus supinator supinated forearm, ie it rotates around the forearm longitudinal axis so that the thumb is pointing outwards. If it fails, with stretched elbow joint no longer supination is possible. (When flexed elbow joint and the biceps brachii supination. )

Supinatorsyndrom

In hypertrophy of the musculus supinator may cause compression of the deep branch of the radial nerve. Consequently, it may be paralyzed but innervated the deep branch next to the musculus supinator no extensor muscles of the forearm, but only some extensors in hand ( abductor pollicis longus, extensor pollicis brevis, extensor pollicis longus, musculus extensor indicis ) and is not afferent, causing the symptom of "drop-wrist " is absent, and no sensory disturbances occur, but merely a stretching and Abduktionsschwäche in the thumb.

For decompression of the lateral origin of the muscle is severed supinator usually.