Muscle · Upper arm

Extensor carpi radialis longus

Musculus extensor carpi radialis longus

The upper of the two radial wrist extensors, lying just behind brachioradialis on the thumb side of the forearm. It straightens the wrist and tips the hand toward the thumb, and its most important job is one you never notice: when the fingers curl to grip, the wrist extensors must fire just as hard to stop the wrist folding under them, so a strong grip is really a forearm-wide effort. Unlike its shorter partner it arises above the elbow, from the ridge on the humerus rather than the shared extensor tendon.