Which muscles are the primary plantarflexors of the foot?

• A. Gastrocnemius and Soleus
• B. Tibialis anterior and Extensor digitorum longus
• C. Peroneus longus and Peroneus brevis
• D. Plantaris and Tibialis posterior

Answer: (D)

Plantarflexion is produced by muscles on the back of the leg that cross the ankle and pull the foot downward. The deep posterior group contributes a lot to this motion, with tibialis posterior playing a major role in plantarflexion and in controlling the foot during push-off. Plantaris, though small, runs with the Achilles tendon and adds a bit of extra plantarflexion force. While the gastrocnemius and soleus are the strongest plantarflexors overall, the combination of plantararis and tibialis posterior highlights the muscles most consistently involved in driving the foot downward across different knee positions and in stabilizing the arch during movement. The other muscles listed either dorsiflex the ankle or primarily evert the foot rather than plantarflex it, so they don’t serve as the primary plantarflexors in the same way.