Meet your Muscles: Gastrocnemius

You may be thinking, what or where on earth is that muscle? It is actually the big muscle at the back of your calf. You could think of it as the bicep of the leg. The gastrocnemius muscle, or gastroc, is another important muscle needed for proper leg movement. It is primarily involved in quick or ballistic movements like running and jumping. Similar to the biceps, the gastrocnemius has 2 heads that come off the muscle belly and attaches to bone.

The Anatomy

Lateral Head

The lateral head of the gastroc begins or originates from the outside of the femur (thigh bone). The muscle continues down the calf to where it becomes a tendon, known as the Achilles Tendon. The function of the gastrocnemius is to bend at the knee and plantar flex at the ankle (pointing the toe).

Medial Head

The medial head of the gastrocnemius originates from the inside of the femur. The muscle continues down the calf and attaches to the lateral head. They join together to form the Achilles Tendon. The medial head provides the same movement by flexing the knee and plantar flexing the ankle.

What is the injury and how does it happen?

Tennis Leg is an injury that results in a repetitive strain to the medial aspect of the gastrocs. This happens with a quick, ballistic push off with the foot. This motion is often used in Tennis when the player does a quick push off with the back leg to strike the ball.

Calf strains are a very common injury. There are many sports that require bursts of speed, quick stops and turns. However, sports are not the only way to injure your calf muscle. Sometimes bad falls will strain or tear the muscle as well.

Achilles Tendon Rupture is a complete tear of the tendon that attaches the gastrocnemius and soleous to the heel of the foot. If the tendon is torn, the result is a loss of plantar flexion (the ability to point the toe). You can injure the tendon by sudden or forced movements of the ankle joint or a direct trauma to the area.

Calf spasms are annoying and painful. It is the most common place to get a muscle cramp and often it happens when you are sleeping!


  • Sudden sharp pain at the back of the leg
  • Loss of motion/muscle weakness
  • Swelling/bruising at the pain site
  • Audible snap sound (if rupture occurs)
  • Limping (pain when putting weight on the leg)


The key to prevention is to have a balance of strength and flexibility. This is another multi-joint muscle so the exercises are plentiful. 5 great examples are:

  1. Double Leg Calf Raises
  2. Single Leg Calf Raises
  3. Farmer’s Walk on toes (walking on toes)
  4. Jump Rope
  5. Jump Squats

The exercises above can be done by beginners, intermediate and advanced fitness levels. You can increase the challenge by simply adding weights or resistance versus using just body weight. We have a lower body mini circuit that would be great to give a try. You can keep track of your time and see if you improve each time you do the circuit!

Remember: the quality of movement is better than the quantity.