Extensor Carpi Radialis Brevis, Posterior View

Description

Running along the dorsolateral forearm, the extensor carpi radialis brevis (ECRB) appears as a short, muscular belly arising from the lateral epicondyle of the humerus and blending distally into a flat tendon that courses toward the dorsal wrist. Laterally, it sits deep to the brachioradialis proximally and adjacent to the extensor carpi radialis longus, while medially it borders the extensor digitorum as the common extensor mass fans toward the hand. Distal to the elbow, the tendon tracks toward the base of the third metacarpal, passing beneath the extensor retinaculum in the second dorsal compartment alongside the extensor carpi radialis longus. Key landmarks stay readable. The posterior perspective clarifies how the ECRB lies superficial to the supinator near the radial head and how its line of pull favors wrist extension with a radial deviation component. Lateral epicondylitis centers on the ECRB origin. Microtearing at its proximal tendon and the extensor carpi radialis brevis portion of the common extensor tendon explains the focal tenderness just distal and anterior to the lateral epicondyle, and it guides injection placement, counterforce bracing, and operative debridement. The arrangement also matters for posterolateral elbow surgery, where the radial nerve and its posterior interosseous branch travel anterior to the lateral epicondyle and into the supinator, close enough that retraction and forearm rotation change their risk profile. Use this artwork for upper limb anatomy labs, sports medicine teaching on tennis elbow, and operative atlases describing lateral epicondyle exposure and the extensor compartments at the wrist. It also fits rehabilitation manuals that need a clean posterior map of wrist extensor tendons across the distal forearm and hand. Anatomical accuracy verified by SciePro's Medical Advisory Board.