What is the medical term for the main muscle of the calf?

The main muscle of the calf is known as the gastrocnemius. This muscle is a large, prominent muscle that forms the bulk of the calf and is responsible for plantarflexion of the foot at the ankle joint, as well as flexion of the knee. It is one of the two muscles that make up the triceps surae, which is a group of muscles located at the back of the lower leg that works together to facilitate movement, particularly during activities such as running and jumping. The gastrocnemius is easily identifiable and contributes significantly to the shape and function of the lower leg.

In contrast, the other options refer to different muscles in the leg. The tibialis anterior is located in the front part of the lower leg and primarily allows dorsiflexion of the foot. The triceps surae includes both the gastrocnemius and the soleus muscles, making it a broader term for the muscle group rather than the specific main muscle. The fibularis longus is found on the lateral side of the lower leg and is involved in eversion of the foot. Thus, the gastrocnemius distinctly qualifies as the main muscle of the calf due to its size and primary functions.