Which muscles are antagonists to dorsiflexion at the ankle?

• A. Tibialis anterior
• B. Gastrocnemius and soleus
• C. Extensor digitorum longus
• D. Fibularis longus

Answer: (B)

Dorsiflexion is the movement of bringing the top of the foot toward the shin. The muscles that produce plantarflexion—pushing the foot downward and away from dorsiflexion—are the primary antagonists. The gastrocnemius and soleus form the calf and attach to the heel via the Achilles tendon; when they contract, they point the toes downward and raise the heel, opposite to dorsiflexion. This plantarflexor pair works together to oppose the dorsiflexors, which are mainly located on the front of the leg (like the tibialis anterior and extensor digitorum longus).

It’s also helpful to note that the gastrocnemius crosses both the knee and the ankle, so its ability to plantarflex depends somewhat on knee position, being more effective with the knee extended. The other options include muscles that contribute to dorsiflexion or assist in other movements, so they don’t serve as the primary antagonists to dorsiflexion.