Which combination of muscles would be best to stimulate with functional electrical stimulation (FES) to improve dorsiflexion and foot clearance during swing in a patient with foot drop?

Which combination of muscles would be best to stimulate with functional electrical stimulation (FES) to improve dorsiflexion and foot clearance during swing in a patient with foot drop?

• A. gastrocnemius
• B. tibialis posterior
• C. tibialis anterior and extensor digitorum longus
• D. peroneus longus and tibialis anterior

Answer: (D)

The key idea is to activate muscles that produce ankle dorsiflexion and help clear the foot during swing. Tibialis anterior is the primary dorsiflexor, so stimulating it raises the foot to clear the ground. Pairing it with peroneus longus adds eversion of the foot, which can help position the forefoot more laterally during swing and reduce toe drag, giving a safer, more assured clearance in some patients with foot drop. The other options either promote plantarflexion (which would oppose dorsiflexion) or miss the toe-clearance component provided by additional dorsiflexor/extensor activation. So combining tibialis anterior with peroneus longus offers both upward foot lift and a favorable foot orientation for clearance during swing.

The key idea is to activate muscles that produce ankle dorsiflexion and help clear the foot during swing. Tibialis anterior is the primary dorsiflexor, so stimulating it raises the foot to clear the ground. Pairing it with peroneus longus adds eversion of the foot, which can help position the forefoot more laterally during swing and reduce toe drag, giving a safer, more assured clearance in some patients with foot drop. The other options either promote plantarflexion (which would oppose dorsiflexion) or miss the toe-clearance component provided by additional dorsiflexor/extensor activation. So combining tibialis anterior with peroneus longus offers both upward foot lift and a favorable foot orientation for clearance during swing.