Anconeus

From Freepedia

The anconeus muscle is a small muscle on the posterior surface of the elbow. There are suggestions that this muscle is embryologically the fourth head of the triceps brachii muscle. The limbs are derived from embryologically similar origins and since the lower limb muscle quadriceps femoris muscle has four heads, it would seem to make sense.

Attachments

It runs from the lateral epicondyle of the humerus proximally to the lateral surface of the olecranon process and the superior part of the posterior ulna distally.

Action

It is partly blended in with the triceps, which it assists in extension of the forearm. It also stabilises the elbow and abducts the ulna during pronation.

Innervation

It is supplied (as is triceps) by the radial nerve from spinal roots C7, C8, and T1.