The anconeus is a triangular muscle of the proximal end of forearm. Lying behind and right below the elbow joint, it arises from the lateral epicondyle of the humerus. Then it extends obliquely downwards to be inserted into the upper fourth portion of the posterior surface of the shaft of the ulna, with its muscle fibers traveling slantingly and medially towards the ulna.
Action/Function
Abduction of the distal end of the ulna during pronation; hinge-like flexion and extension of the elbow joint.
Blood supply
The anconeus is supplied by small branches coming off the posterior interosseous recurrent and the ulnar recurrent artery.
Innervation
It is innervated by radial nerve.
Below, drawing of anconeus muscle, partially hidden by the flexor carpi ulnaris and other muscles.