The tibial nerve is a branch of the sciatic nerve. The tibial nerve passes through the popliteal fossa to pass below the arch of soleus.

Structure

Popliteal fossa

The tibial nerve is the larger terminal branch of the sciatic nerve with root values of L4, L5, S1, S2, and S3. It lies superficial (or posterior) to the popliteal vessels, extending from the superior angle to the inferior angle of the popliteal fossa, crossing the popliteal vessels from lateral to medial side. It gives off branches as shown below:

Back of the leg

At the inferior angle of the popliteal fossa, tibial nerve passes deep to the tendinous arch of soleus to enter the back of the leg. In the leg, it runs downwards and medially to reach the posteromedial side of the ankle, midway between the medial malleolus and medial tubercle of the calcaneum. It terminates deep to the flexor retinaculum at the origin of the abductor hallucis by dividing into medial and lateral plantar nerves to supply the foot. The tibial nerve gives off several branches to supply the back of the leg:

Foot

In the foot, the nerve terminates by dividing into medial and lateral plantar branches.

Clinical significance

Damage to the tibial nerve is rare, and is often a result of direct trauma, entrapment through narrow space or compression for long period of time. Damage results in loss of plantar flexion, loss of flexion of toes and weakened inversion (The tibialis anterior can still invert the foot).

Additional images