Which muscle dorsiflexes the foot at the ankle?

• A. Gastrocnemius
• B. Tibialis anterior
• C. Soleus
• D. Peroneus longus

Answer: (B)

Dorsiflexion at the ankle means lifting the front of the foot toward the shin. The primary muscle doing this is the tibialis anterior, located in the front of the lower leg. Its tendon crosses to the medial side of the foot (medial cuneiform and the first metatarsal), so when it contracts it pulls the foot upward and slightly inward.

The other muscles listed move the foot in the opposite directions or perform different actions: the gastrocnemius and soleus are the main plantarflexors, pulling the heel up and bending the foot downward. The peroneus longus is on the lateral side and mainly everts the foot and assists in plantarflexion. So the muscle that dorsiflexes the foot is tibialis anterior.