Muscle · Elbow

Anconeus

Musculus anconeus

A small triangle of muscle filling the hollow at the back of the elbow, between the bony point on the outer side of the humerus and the top of the ulna. It is effectively a detached lower corner of triceps and works with it, adding a small amount to straightening the elbow. Its more interesting job is what it does while the forearm turns: it holds the ulna steady so that the radius can rotate around it cleanly. Because it sits directly under the skin in a shallow triangle with two bony corners, it is one of the easiest deep elbow muscles to find by touch.