Which sensory area is preserved in an isolated deep peroneal nerve injury?

• A. Lateral malleolar region
• B. Dorsum of the foot
• C. First web space between toes
• D. Sole of the foot

Answer: (D)

The deep peroneal nerve supplies sensation to a small area on the dorsum of the foot—the first web space between the big toe and the second toe—and it also motorizes the anterior compartment. An isolated injury to this nerve will abolish sensation in that first web space, but the rest of the sole of the foot remains innervated by the tibial nerve via the plantar nerves. Therefore, the sole of the foot is preserved in this scenario. Testing sensation between the first and second toes is a quick way to assess deep peroneal nerve function, while plantar (sole) sensation remains intact because it’s supplied by the tibial nerve.