Origin: Lateral epicondyle of the humerus
Insertion: Lateral surface of the olecranon process and the superior part of the posterior ulna
Artery: Profunda brachii, recurrent interosseous artery
Nerve: Radial nerve (C7, C8, and T1)
Action: Partly blended in with the triceps, which it assists in extension of the forearm. Stabilises the elbow and abducts the ulna during pronation.
The Anconaeus is a small triangular muscle which is placed on the back of the elbow-joint, and appears to be a continuation of the Triceps brachii. It arises by a separate tendon from the back part of the lateral epicondyle of the humerus; its fibers diverge and areinserted into the side of the olecranon, and upper fourth of the dorsal surface of the body of the ulna.