In addition to elbow extension, what is another function of the anconeus?

The anconeus is a small muscle located at the posterior aspect of the elbow joint, primarily responsible for elbow extension. However, it also plays a significant role in movements associated with forearm pronation. One of its secondary functions is to assist in the abduction of the ulna during pronation. This is crucial for maintaining proper alignment and movement mechanics, allowing for a smoother rotation of the forearm.

The other functions listed in the choices do not accurately describe the anconeus's role. The muscle is not involved in shoulder movements such as mediating rotation or adduction, nor does it contribute to flexing the elbow, which would primarily be the responsibility of other muscles like the biceps brachii and brachialis. Therefore, understanding the anatomical function of the anconeus reinforces its role in both elbow extension and assisting with specific movements of the ulna during forearm pronation.