Communicating branch with ulnar nerve

The medial branch of the Superficial Branch of the Radial Nerve communicates, above the wrist, with the dorsal branch of the lateral antibrachial cutaneous, and, on the back of the hand, with the dorsal branch of the ulnar nerve. It then divides into four digital nerves (Dorsal digital branches), which are distributed as follows: the first supplies the ulnar side of the thumb; the second, the radial side of the index finger; the third, the adjoining sides of the index and middle fingers; the fourth (Communicating branch with ulnar nerve) communicates with a filament from the dorsal branch of the ulnar nerve, and supplies the adjacent sides of the middle and ring fingers.