Common plantar digital branches of lateral plantar nerve

At a glance

English

Common plantar digital branches of lateral plantar nerve

Latin (TA2)

Rami digitales plantares communes nervi plantaris lateralis

System

Nerve

Region

Lower limb

Side

Paired, left and right

About the common plantar digital branches of lateral plantar nerve

On the lateral side of the sole, near the base of the fifth metatarsal, the lateral plantar nerve divides into a superficial and a deep branch. The superficial branch gives rise to two digital branches. One runs to the lateral side of the little toe; the other runs forwards to the cleft between the fourth and fifth toes. In the official terminology the second is the true common plantar digital nerve of the lateral plantar nerve, since it later divides for two toes, while the first acts as a proper digital nerve from the start.

The branch to the little toe runs along the lateral border of the sole on flexor digiti minimi brevis and gives that muscle its motor supply; it often supplies the interossei of the fourth space as well. It then continues along the outer edge of the fifth toe to its tip. The branch to the fourth web space passes forwards between slips of the plantar aponeurosis, communicates with the third common digital nerve of the medial plantar nerve, and near the web divides into proper digital nerves for the facing sides of the fourth and fifth toes.

Together these branches carry sensation from the plantar skin of the lateral one and a half toes, their nail beds by small dorsal twigs, and the adjacent part of the lateral forefoot. This mirrors the ulnar nerve in the hand, which serves the little finger and half the ring finger. The communication with the medial plantar nerve means that sensation in the fourth toe and third web space can be shared and is variable.

The junction of medial and lateral plantar fibres in the third web space, and the common nerve's position under the deep transverse metatarsal ligament, are thought to explain why Morton's neuroma usually develops there and sometimes in the fourth space. It causes burning pain and numbness in the toes, worse in tight shoes. Fractures of the fifth metatarsal and surgery on the lateral forefoot can injure these branches.

Course and supply

Arises from

The superficial branch of the lateral plantar nerve, near the base of the fifth metatarsal.

Ends in

Ends as proper digital nerves to the lateral side of the little toe and to the facing sides of the fourth and fifth toes.

Supplies

Sensory to the plantar skin of the lateral one and a half toes; the little toe branch also supplies flexor digiti minimi brevis.