Tibial nerve

Roots

L4–S3, the sciatic's larger division.

Course

Descends vertically through the popliteal fossa, runs deep to the soleus' tendinous arch, continues between the superficial and deep flexor compartments on the tibialis posterior, and passes behind the medial malleolus through the tarsal tunnel, dividing into medial and lateral plantar nerves.

Motor supply

The posterior compartment's plantarflexors — gastrocnemius, soleus, tibialis posterior and the toe flexors — plus the foot's intrinsic muscles via plantar branches.

Sensory supply

The sole of the foot via the plantar nerves; the calf via sural branches.

Clinical relevance

Tarsal tunnel syndrome — burning sole pain — entraps it behind the medial malleolus; the ankle jerk (S1) tests its reflex arc, and its loss flags peripheral neuropathy's advance.

Related conditions

• Peripheral neuropathy