Which nerve is most commonly implicated in foot drop when injured?

Which nerve is most commonly implicated in foot drop when injured?

• A. Tibial nerve
• B. Deep peroneal nerve
• C. Ulnar nerve
• D. Femoral nerve

Answer: (B)

Foot drop happens when the muscles that lift the front of the foot (dorsiflexors) are weakened because their nerve is damaged. The deep peroneal nerve provides the main motor supply to those dorsiflexor muscles—tibialis anterior, extensor digitorum longus, extensor hallucis longus, and the extensor digitorum brevis. When this nerve is injured, dorsiflexion is lost, so the foot “drops” during walking. The other nerves listed don’t control those dorsiflexors: the tibial nerve powers plantar flexion, while the ulnar and femoral nerves affect the hand and thigh, respectively.

Foot drop happens when the muscles that lift the front of the foot (dorsiflexors) are weakened because their nerve is damaged. The deep peroneal nerve provides the main motor supply to those dorsiflexor muscles—tibialis anterior, extensor digitorum longus, extensor hallucis longus, and the extensor digitorum brevis. When this nerve is injured, dorsiflexion is lost, so the foot “drops” during walking. The other nerves listed don’t control those dorsiflexors: the tibial nerve powers plantar flexion, while the ulnar and femoral nerves affect the hand and thigh, respectively.