The soleus action is to do what?

• A. Dorsiflex the ankle
• B. Plantar flex the ankle
• C. Invert the foot
• D. Evert the foot

Answer: (B)

Plantarflexion of the ankle is the soleus’s primary action. This muscle sits in the deep posterior leg and inserts into the calcaneus via the Achilles tendon, crossing only the ankle joint. Contraction shortens the calf and pushes the body forward or raises the heel, which is exactly plantarflexion. Dorsiflexion, the opposite movement, is mainly performed by muscles in the front of the leg like the tibialis anterior. Inversion and eversion involve turning the sole of the foot in or out and are carried out by other muscles around the ankle and subtalar joints. So the soleus specializes in plantarflexing the ankle, not dorsiflexing, inverting, or everting the foot.