Nerves - Tibial

Question 1

What nerve roots make up the tibial nerve?

Answer 1

L4 - S3

Question 2

Sensory control?

Answer 2

Innervates the skin of the posterolateral leg, lateral foot and the sole of the foot.

Question 3

Motor control?

Answer 3

Innervates the posterior compartment of the leg and the majority of the intrinsic foot muscles.

It supplies the deep muscles of the posterior leg.

Question 4

Pathway of the nerve

Answer 4

A branch of the sciatic nerve.

Arises at the apex of the popliteal fossa.

It gives of a branch of the sural nerve that innervates the posterolateral aspect of the leg.

The nerve passes inferior and posteriorly to the medial malleolus, through a structure called the tarsal tunnel. Within this tunnel, branches arise to innervate the cutaneous heel.

Immediately distal to the tarsal tunnel, the tibial nerve terminates by dividing into sensory branches, which innervates the sole of the foot.

Question 5

Clinical relevance: tarsal tunnel syndrome

Answer 5

A condition where the tibial nerve is compressed within the tarsal tunnel (posterior to the medial malleolus). There are varying causes, 3 of which are:

1) Osteoarthritis
2) Rheumatoid arthritis
3) Post-trauma ankle deformities

Patients complain of paraesthesia in the ankle and sole of the foot, which can radiate up the leg slightly. Aggravated by activity and alleviated by rest.

Tarsal tunnel symptoms can be treated conservatively by anti-inflammatory drugs and change in footwear.

Cutting the flexor retinaculum can be cut surgically, which releases the pressure.