innerbody
Diagram

Gastrocnemius Muscle (Lateral Belly)

The gastrocnemius muscle, sometimes called the leg triceps, is the largest of the muscles of the lower leg, a pennate muscle forming the bulk of the calf. The lateral belly of the gastrocnemius muscle is the smaller of the paired lateral and medial bellies. It arises from the lateral head, connected to the femur’s lateral condyle and some of the bone just above the condyle. Fired by the tibial nerve Continue Scrolling To Read More Below...

Continued From Above... and in its attachment with the posterior calcaneus through the Achilles tendon (calcaneal tendon) - via an aponeurosis formed in conjunction with the soleus muscle - the gastrocnemius pulls the heel, drawing it upward and thereby extending the toe of the foot in a downward direction, allowing the foot to push off from the ground. To a lesser extent, it helps bend the knee joint, flexing the entire leg. The gastrocnemius muscle begins at the back of the knee between the kneecap (patella) and the femur of the upper leg.