After branching off from the sciatic nerve, it runs obliquely downward and outward along the medial edge of the biceps femoris, passes through the upper and outer side of the popliteal fossa, reaches between the biceps femoris tendon and the lateral head of the gastrocnemius, passes through the deep surface of the peroneus longus and bypasses the fibular neck, and is divided into two terminal branches, the deep peroneal nerve and the superficial peroneal nerve. It innervates the peroneus longus and brevis, tibialis anterior, extensor hallucis longus, extensor digitorum longus, extensor hallucis brevis, extensor digitorum brevis, and the skin sensation of the lateral side of the calf and the dorsum of the foot.