Which muscle acts as the antagonist to foot eversion?

• A. Peroneus longus
• B. Tibialis anterior
• C. Extensor digitorum longus
• D. Flexor digitorum longus

Answer: (B)

Foot eversion involves turning the sole outward, a movement mainly produced by the lateral (fibular) muscles of the leg. To oppose that outward turn, you need a muscle that inverts the foot (turns the sole inward) and often helps lift the foot upward. The tibialis anterior does exactly this: it dorsiflexes the foot at the ankle and inverts the foot, pulling the sole medially and counteracting eversion. That makes it the clearest antagonist to foot eversion.

The other muscles don’t counter eversion as effectively. The peroneus longus promotes eversion (and plantarflexion) rather than opposing it. The extensor digitorum longus mainly extends the toes and dorsiflexes the ankle, with only a secondary role in eversion. The flexor digitorum longus plantarflexes the foot and toes and also inverts, but its inversion isn’t as directly opposing eversion as the tibialis anterior.