Plantarflexion of the foot. Artwork of the muscles of the foot from the side, with red arrows showing the direction of movement when flexing the foot in the direction of its lower (plantar) surface (plantarflexion). The main muscles involved are the gastrocnemius and soleus (calf muscle), flexor hallucis longus, flexor digitorum longus, and tibialis posterior. These muscles of the lower leg extend downwards into the foot. The nerve used is the tibial nerve. This is the right foot. For the left foot, see C016/6800.