Which nerve provides sensation to the lateral leg and innervates the peroneus longus and peroneus brevis; injury can lead to foot drop?

Which nerve provides sensation to the lateral leg and innervates the peroneus longus and peroneus brevis; injury can lead to foot drop?

• A. Tibial nerve
• B. Common peroneal nerve
• C. Sural nerve
• D. Superficial peroneal nerve

Answer: (B)

The key idea is a nerve that both feels the lateral leg skin and supplies the muscles that ever the foot and shape the dorsiflexion pattern. The common peroneal (fibular) nerve travels around the fibular head and then divides into deep and superficial branches. Its lateral sural cutaneous branch provides sensation to the lateral aspect of the leg, and its branches give rise to nerves that innervate the muscles of the lateral compartment, including the peroneus longus and peroneus brevis. Because the deep branch runs to the dorsiflexors, injury to this nerve can lead to foot drop due to loss of dorsiflexion, while the lateral leg sensation is lost via the lateral sural cutaneous contribution. Other nerves don’t fit both parts together: the tibial nerve supplies the posterior compartment and plantar foot sensation; the sural nerve is purely sensory; and the superficial peroneal nerve supplies the peroneus longus and brevis but does not cover sensation of the lateral leg. Thus, the common peroneal nerve best matches the described pattern.

The key idea is a nerve that both feels the lateral leg skin and supplies the muscles that ever the foot and shape the dorsiflexion pattern. The common peroneal (fibular) nerve travels around the fibular head and then divides into deep and superficial branches. Its lateral sural cutaneous branch provides sensation to the lateral aspect of the leg, and its branches give rise to nerves that innervate the muscles of the lateral compartment, including the peroneus longus and peroneus brevis. Because the deep branch runs to the dorsiflexors, injury to this nerve can lead to foot drop due to loss of dorsiflexion, while the lateral leg sensation is lost via the lateral sural cutaneous contribution.

Other nerves don’t fit both parts together: the tibial nerve supplies the posterior compartment and plantar foot sensation; the sural nerve is purely sensory; and the superficial peroneal nerve supplies the peroneus longus and brevis but does not cover sensation of the lateral leg. Thus, the common peroneal nerve best matches the described pattern.