Which nerve can be electrically stimulated at the ankle to produce flexion of the toes?

Which nerve can be electrically stimulated at the ankle to produce flexion of the toes?

• A. Posterior tibial nerve
• B. Saphenous nerve
• C. Deep peroneal nerve
• D. Superficial peroneal nerve

Answer: (A)

Toe flexion depends on the plantar flexor and toe flexor muscles in the posterior compartment of the leg, all of which are supplied by the tibial nerve. When the tibial nerve is stimulated near the ankle, it activates the flexor digitorum longus, flexor digitorum brevis, and flexor hallucis longus, causing the toes to curl downward. The saphenous nerve is purely sensory to the medial leg and foot, so stimulating it won’t produce toe movement. The deep peroneal nerve innervates the anterior compartment and toe extensors, leading to toe extension rather than flexion when stimulated. The superficial peroneal nerve supplies most of the lateral leg and foot evertors, with little impact on toe flexion. Thus, stimulation of the posterior tibial nerve at the ankle best produces toe flexion.

Toe flexion depends on the plantar flexor and toe flexor muscles in the posterior compartment of the leg, all of which are supplied by the tibial nerve. When the tibial nerve is stimulated near the ankle, it activates the flexor digitorum longus, flexor digitorum brevis, and flexor hallucis longus, causing the toes to curl downward. The saphenous nerve is purely sensory to the medial leg and foot, so stimulating it won’t produce toe movement. The deep peroneal nerve innervates the anterior compartment and toe extensors, leading to toe extension rather than flexion when stimulated. The superficial peroneal nerve supplies most of the lateral leg and foot evertors, with little impact on toe flexion. Thus, stimulation of the posterior tibial nerve at the ankle best produces toe flexion.