Plantar Flexor Muscles

A number of muscles functioning to move the ankle, foot, and toes are located in the lower leg. They attach the femur (upper leg bone), tibia, and fibula (lower leg bones) and to various bones in the foot and are responsible for a variety of movements - moving the foot upward (dorsiflexion) or downward (plantar flexion), and turning the sole of the foot inward (inversion) or outward (eversion). The "plantar muscles" include the following: The "gastrocnemius," on the back of the lower leg, forms part of the calf. It comes from two immovable ends (or heads) located on the femur, one on the side and one toward the center. The far end of this muscle joins the strong "Achilles tendon," which descends to the heel and attaches to the calcaneus. The gastrocnemius is a powerful plantar flexor of the foot, that aids in pushing the body forward when a person walks or runs. It also works to flex the leg at the knee. The "soleus" is a thick, flat muscle located beneath the gastrocnemius. These two muscles make up the calf of the leg. The soleus rises from the tibia and fibula, and it extends to the heel by way of the Achilles tendon. It acts with the gastrocnemius to cause plantar flexion of the foot. The "flexor digitorum longus" extends from the back surface of the tibia to the foot. Its tendon passes along the plantar surface of the foot. There, it divides into four parts that attach to the terminal bones of the four small toes. It assists in plantar flexion of the foot, flexion of the four small toes, and inversion of the foot.