Which nerve injury would most likely cause loss of dorsiflexion and a foot drop, presenting with a high-stepping gait?

• A. Tibial nerve injury
• B. Sciatic nerve injury
• C. Common peroneal nerve injury
• D. Femoral nerve injury

Answer: (C)

Dorsiflexion is powered by muscles in the anterior compartment of the leg, notably tibialis anterior, which are innervated by the deep branch of the peroneal (fibular) nerve. When the common peroneal nerve is injured—especially around the fibular neck—the deep and superficial branches can be affected, leading to weakness of dorsiflexion and toe extension. This produces foot drop, and people often adopt a high-stepping gait to clear the foot during swing.

Other nerves would produce different patterns: the tibial nerve mainly impairs plantarflexion and foot inversion, the femoral nerve affects hip flexion and knee extension, and the sciatic nerve injury would cause broader, more mixed deficits. The presentation described most specifically points to injury of the common peroneal nerve.