ABSTRACT
The superficial ramus, or branch, divides from the radial nerve as it lies in the radial cubital sulcus. As shown in Figure 26.1, this branch travels distally over the supinator muscle and the pronator teres. Passing over the pronator teres muscle, the nerve dips under the ulnar border of the brachioradialis muscle and bends dorsally to run along the radius. The superficial branch, at a point between the middle and distal thirds of the radius, arches dorsally through a tunnel in the antebrachial fascia to terminate in the skin beyond the radial styloid. The dorsal digital nerves, the terminal branches of the superficial branch, supply sensation to the dorsal skin of the first, second, and radial side of the third digits to the base of the second phalanx. As skin dermatomes overlap, the only autonomous region of the superficial radial nerve is the dorsal web space closest to the thumb.
