The superficial muscles of the posterior compartment of the forearm, from lateral to medial, are the

These superficial muscles have a similar superior attachment to the humerus, mostly through the common extensor tendon attached to the lateral epicondyle (extensor carpi radialis brevis, extensor digitorum, extensor digiti minimi, and extensor carpi ulnaris muscles). The brachioradialis and extensor carpi radialis longus muscles originate from the lateral supracondylar ridge and the anconeus muscle from the posterior surface of the lateral epicondyle. From this common area, the muscle bellies of the superficial muscles run parallel to the axis of the forearm toward the wrist and hand. The primary action of these superficial muscles is to extend or abduct the wrist. Unique to the superficial muscle group, because they perform elbow functions, are the brachioradialis and anconeus muscles.

The anconeus muscle is a small muscle on the lateral aspect of the elbow that extends from the lateral epicondyle of the humerus to the lateral olecranon process of the ulna. It assists the triceps brachii muscle in extending the forearm.

The deep group of muscles in the posterior compartment of the forearm, from lateral to medial, are the