Proper plantar digital branches of medial plantar nerve

At a glance

English

Proper plantar digital branches of medial plantar nerve

Latin (TA2)

Rami digitales plantares proprii nervi plantaris medialis

System

Nerve

Region

Lower limb

Side

Paired, left and right

About the proper plantar digital branches of medial plantar nerve

The medial plantar nerve ends in seven proper plantar digital nerves. One leaves the main trunk early and runs along the medial side of the great toe. The other six come in pairs from the three common plantar digital nerves, which divide near the toe webs: one pair for the facing sides of the first and second toes, one for the second and third, and one for the third and fourth. Together they cover the plantar skin of the great, second and third toes and the medial half of the fourth.

Each proper nerve runs along the side of its toe on the plantar surface, alongside a plantar digital artery, giving fine twigs to the skin and to the joints of the toe. Opposite the last phalanx each sends a branch around onto the dorsum to supply the nail bed and the skin around the nail, so the tips of these toes are served from the sole rather than by the dorsal nerves. The remainder ends in the pulp of the toe. The nerve to the medial side of the great toe also carries motor fibres to flexor hallucis brevis, which it gives off before reaching the toe.

The pattern copies the median nerve in the hand, which serves the palmar skin and nail beds of the thumb, index, middle and half the ring finger. The nerve for the third and fourth toes may receive extra fibres from the lateral plantar nerve, so the border with lateral plantar territory varies.

These nerves can be injured in toe surgery, notably bunion correction, where the great toe's medial digital nerve lies close to the incision and its damage leaves a numb or painful strip. Pressure from a bunion or tight footwear can irritate it, a condition sometimes called Joplin's neuroma. Being the longest sensory fibres in the body, the toe nerves are early casualties in length-dependent neuropathies such as diabetic neuropathy. A ring block at the base of a toe anaesthetises them for nail procedures.

Course and supply

Arises from

The medial plantar nerve directly (for the medial side of the great toe) and its three common plantar digital nerves.

Ends in

End in the plantar skin, joints, pulp and nail beds of the great, second and third toes and the medial side of the fourth.

Supplies

Sensory to the plantar surface and nail beds of the medial three and a half toes; the great toe's medial nerve also carries motor fibres to flexor hallucis brevis.