Common Palmar Digital Branches of Ulnar Nerve

Origin

The common palmar digital branches arise from the superficial branch of ulnar nerve, below the flexor retinaculum in the palmar aspect of the hand.

Course

The ulnar nerve enters the palm by passing superficial to the flexor retinaculum and lateral to pisiform bone, while being covered by a superficial slip of the retinaculum (volar carpal ligament). At the distal border of retinaculum, the nerve terminates by dividing into its superficial and deep branches.

Just distal to the pisiform bone, the superficial branch gives off two palmar digital branches. The medial of the two branches is a proper palmar digital nerve which innervates the skin of the medial side of the little finger. The lateral branch is a common palmar digital nerve, which further divides into two proper palmar digital nerves. These innervate the skin of adjacent sides of the ring and little fingers. It also sends a communicating branch to the palmar digital nerves of the median nerve.

The common palmar digital nerves of the ulnar nerve have a similar course as those from the median nerve. They traverse deep to the superficial palmar arch and its associated digital vessels.

Branches

Proper palmar (or volar) digital nerves arise from the common digital branches of the ulnar nerve inside the palmar aspect of the hand.

Supplied Structures

The common palmar digital branches of the ulnar nerve provide cutaneous sensory innervation to the skin of adjacent sides of the ring and little fingers.