Which nerve injury is most likely to present with foot drop after prolonged leg compression?

• A. Deep peroneal nerve injury
• B. Tibial nerve injury
• C. Femoral nerve injury
• D. Saphenous nerve injury

Answer: (A)

Foot drop happens when the muscles that lift the front of the foot can’t contract. Those muscles are in the anterior compartment of the leg and are innervated by the deep branch of the peroneal (fibular) nerve. Prolonged leg compression commonly injures the common peroneal nerve as it wraps around the fibular neck, and impact on the deep peroneal branch specifically weakens dorsiflexion, leading to foot drop. If the injury were to the tibial nerve, plantar flexion would be affected instead, not dorsiflexion. The femoral nerve governs hip flexion and knee extension, so its injury would present with different motor deficits. The saphenous nerve is purely sensory, so it wouldn’t cause motor weakness like foot drop. This is why the deep peroneal nerve injury is the best explanation for foot drop after prolonged leg compression.