The big calf muscle at the rear of the lower leg.
Muscle in the back part of the leg that makes up the greater part of the calf.
Muscle of the posterior surface of the lower leg that, when flexed, initiates plantar flexion.
A large superficial muscle along the back of the leg. The gastrocnemius has two heads, one originating along the outside (lateral surface) of the head and condyle of the femur and the other originating along the medial popliteal surface of the femur. Both heads attach via the calcaneal (Achilles) tendon to the back surface of the calcaneus (heel) bone. The gastrocnemius plantar flexes the ankle, flexes the knee, and allows a person to stand on tiptoes. It is innervated by the tibial nerve (SI, S2).