TIBIAL NERVE ANATOMY

The tibial nerve is the larger of the two major divisions of the sciatic nerve. It is derived from L5, S1 and S2 roots. It leaves the popliteal fossa between the heads of the gastrocnemius and supplies all muscles in the posterior compartment of the legs, i.e. gastrocnemius, soleus, plantaris, popliteus, flexor digitorum longus, flexor hallucis longus and tibialis posterior.

At the ankle the tibial nerve runs posterior to the medial malleolus under the flexor retinaculum (tarsal tunnel) to enter the foot. While coming out of (or within) tarsal tunnel, the nerve divides into four branches.

Two of these, the medial and lateral calcaneal nerves are purely sensory and supply sensation to the heel.

The other two branches, the medial and lateral plantar nerves innervate the intrinsic muscles of the foot and provide sensation to the medial and lateral sole respectively. Notably, medial plantar nerve supplies abductor hallucis brevis and lateral plantar nerve supplies abductor digiti quinti pedis.

Reference:

1. Richard S Snell, Clinical Anatomy: Lippincott Williams & Wilkins, 7th edition


2. Cimino WR. Tarsal tunnel syndrome: review of the literature. Foot Ankle 1990, 11:47.


3. Kimura J. Electrodiagnosis in disease of nerve and muscle: Principles and Practice, New York: Oxford V. Press, 3rd edition