The |gastrocnemius| muscle is connected at two joints, the knee and the ankle. It consists of a lateral head, a medial head, and their single ~tendon~ of insertion. Each head is a thick muscular column, separated from the other by the back of the knee. As they descend, they come together. The medial head is larger and wraps around the leg more towards the front than does the lateral head. The muscular heads end at or slightly above the middle of the leg, where they attach to their ~tendon~. The two heads form the bulging "belly" of the calf of the leg. Their ~tendon~ descends and fuses with the ~tendon~ of the |soleus|, which lies just beneath it, forming the Achilles ~tendon~, which inserts in the heel bone. The |gastrocnemius| muscle propels the body when walking, running, or jumping. It raises the heel, which lifts the body. It also assists, though minimally, in flexing the |knee joint|.
