extensor carpi radialis brevis muscle

With the elbow fully extended, the patient feels points of tenderness over the affected point on the elbow-which is the origin of the extensor carpi radialis brevis muscle from the lateral epicondyle (extensor carpi radialis brevis origin).

The dorsal aspect of its base presents on its radial side a pyramidal eminence, the styloid process, which extends upward behind the capitate; immediately distal to this is a rough surface for the attachment of the extensor carpi radialis brevis muscle.

The first groove is broad, but shallow, and subdivided into two by a slight ridge; the lateral of these two transmits the tendon of the extensor carpi radialis longus muscle, the medial the tendon of the extensor carpi radialis brevis muscle.