Dorsal branch of ulnar nerve

The dorsal branch of ulnar nerve arises about 5 cm. proximal to the wrist; it passes backward beneath the Flexor carpi ulnaris, perforates the deep fascia, and, running along the ulnar side of the back of the wrist and hand, divides into two dorsal digital branches; one supplies the ulnar side of the little finger; the other, the adjacent sides of the little and ring fingers.