The tibial nerve is one of two terminal branches of the sciatic nerve and supplies the leg and foot with motor and sensory supply.

Summary

• origin: one of two terminal branches of the sciatic nerve in the lower third of the thigh

• course: courses through the popliteal fossa, passing deep to gastrocnemius to pass under the flexor retinaculum at the ankle

• major branches

  • sural nerve

  • medial and lateral plantar nerves

• motor supply: posterior compartment of the thigh, posterior compartments of the leg (superficial posterior and deep posterior) and the muscles of the sole of the foot

• sensory supply: articular branches to knee, ankle and foot joints; cutaneous branches to posterior calf and sole of the foot

Gross anatomy

Origin

Fibers arise from the anterior divisions of the L4 to S3 nerve roots in the sacral plexus to form the tibial component of the sciatic nerve. It forms its own discrete nerve after the terminal division of the sciatic nerve, usually in the lower third of the thigh.

Course

Passes straight down through the popliteal fossa, posterior to the popliteal vessels, to pass inferiorly between the heads of gastrocnemius and deep to the soleus muscle. In the posterior calf, it continues inferiorly in the midline, deep to the soleus and superficial to the tibialis posterior muscles. At the ankle, it passes under the flexor retinaculum in the tarsal tunnel, enclosed in a synovial sheath containing the posterior tibial vessels. At the level of the medial malleolus it divides into three terminal branches: medial and lateral plantar nerves, and the medial calcaneal nerve.

Branches and supply

• articular twigs to the knee, ankle and foot joints

• muscular branches in the posterior compartment of the thigh (as the tibial part of the sciatic nerve) and the posterior compartments of the leg (superficial posterior and deep posterior compartments

• medial sural cutaneous nerve (which goes on to form the sural nerve along with the lateral sural cutaneous nerve from the common peroneal nerve)

• terminal branches in the foot

  • medial plantar nerve

  • lateral plantar nerve

  • medial calcaneal nerve

Related pathology

• tibial nerve schwannoma