The |extensor carpi radialis| brevis is a short, wide, flattened muscle. It arises from the |humerus| (upper arm bone) and narrows into a long, flat ~tendon~ about two-thirds of the way down the arm. It lies between the |extensor carpi radialis| longus and the |extensor digitorum| along the outer surface of the |radius|. This muscle extends and radially deviates the hand at the wrist joint.
