The surgical importance of the brachialis lies in its nerve supply. The lateral part of the muscle is supplied by the radial nerve, and the medial part is supplied by the musculocutaneous nerve. Thus, the muscle can be split longitudinally without either side being denervated. Because the musculocutaneous nerve is the major nerve supply to the brachialis, even cutting the radial nerve supply to the muscle seems to have little clinical effect. That is why the plane between the brachialis and the adjacent lateral muscle, the brachioradialis, is useful in surgery