What Is the Extensor Carpi Radialis Brevis?
The extensor carpi radialis brevis is a muscle of the posterior compartment of the forearm, found on the same side as the back of the hand. Its name is a nod to its function as an extensor of the wrist or radiocarpal joint, meaning that it bends the wrist backwards. The second part of this muscle’s name refers also to its location, as it is situated on the thumb side of the arm above the radius bone, and to its form, as it is slightly shorter than its sister muscle, the extensor carpi radialis longus. In addition to its action as an extensor of the wrist joint, the extensor carpi radialis brevis abducts the wrist, or bends the hand sideways toward the thumb side.
