The nerves of the leg and foot

The leg below the knee receives all its motor, and much of its sensory innervation from the two terminal branches of the sciatic nerve: the tibial and common peroneal nerves. The tibial nerve supplies the muscles of the posterior (flexor) compartment of the leg and the intrinsic muscles of the plantar foot, as well as the skin of the back of the leg (sural nerve) and the plantar skin. The common peroneal nerve is the only palpable nerve in the lower limb as it winds around the neck of the fibula (where it may be injured). It divides into the superfical peroneal nerve, which supplies the two peroneal foot evertor muscles, and the deep peroneal, supplying the extensor group, as well as sensory supply to the front of the leg and dorsum of the foot, which is reinforced by two sensory branches of the common peroneal – the sural communicating and the lateral cutaneous nerve of the calf. The only nerve below the knee not derived from the sciatic is the saphenous nerve. This nerve arises from the femoral nerve below the groin and supplies skin on the medial side of the knee, leg and foot. It runs with the long saphenous vein in the lower part of its course and can be damaged during operations on the vein.