supinator muscle

It does this just below the insertion of the Supinator muscle.

Its upper third gives insertion to the supinator muscle.

This action is performed by the Biceps brachii and the Supinator muscle.

This action, which is aided by the supinator muscle, requires the elbow to be at least partially flexed.

It is the continuation of the deep branch of the radial nerve, after this has crossed the supinator muscle.

The "radial tunnel" is the region from the humeroradial joint past the proximal origin of the supinator muscle.

If the elbow, or humeroulnar joint, is fully extended, supination is then primarily carried out by the supinator muscle.

The deep branch of the radial nerve pierces the supinator muscle, after which it is known as the posterior interosseous nerve.

The posterior interosseous nerve may be entrapped at the Arcade of Frohse, which is part of the Supinator muscle.

The head is supported on a round, smooth, and constricted portion called the neck, on the back of which is a slight ridge for the insertion of part of the supinator muscle.

It is possible that they relied more on their biceps for forceful supination without the assistance of the supinator muscle like in modern humans, and thus that they used a different movement when throwing.

Arcade of Frohse, sometimes called the supinator arch, is the most superior part of the superficial layer of the supinator muscle, and is a fibrous arch over the posterior interosseous nerve.

The radial nerve divides into deep and sensory superficial branches just proximal to the supinator muscle - an arrangement that can lead to entrapment and compression of the deep part, potentially resulting in selective paralysis of the muscles served by this nerve (the extensor muscles and the abductor pollicis longus.)