The musculo-cutaneous descends between the peroneal muscles and the extensor longus digitorum to pierce the deep fascia, as two branches, in the lower third of the leg. The two branches, the medial and the lateral, pass to the dorsum of the foot over the anterior annular ligament.

Branches

(a) Muscular, to the peroneus longus and peroneus brevis.

(b) Medial, supplies the skin of the lateral aspect of the lower third of the leg, a branch to the medial side of the big toe which communicates with the long saphenous, and a branch to the adjacent sides of the second and third toes.

(c) Lateral. Like the preceding nerve the lateral branch innervates the lateral aspects of the lower third of the leg. On the dorsum of the foot it divides into two, to innervate the adjacent sides of the third, fourth, and fifth toes. It communicates with the short saphenous.

Plate X. Sympathetic System