Gastrocnemius: Definition, Anatomy, Function, Possible Actions and Treatment Against Weakness

It is located on the back of the leg and is a very powerful two-joint or biarticular muscle extended from the back of the knee to the heel.

The definitive shape of the calf is a consequence of the two heads that make up the Gastrocnemius muscle (medial and lateral), which are located in the posterior and upper half of the leg.

The other major muscle of the calf, the soleus, is flat and is below the Gastrocnemius.

Both Gastrocnemius and Soleus run along the leg, connecting behind the knee and the heel. A third muscle, the plantar, extends two to four inches down from the knee and is between the Gastrocnemius and the soleus.

The flexion of this muscle when the body is walking and bends the knee creates traction in the femur, pulling it towards the tibia in the lower part of the leg and causing the knee to bow.

Gastrocnemius muscle and soleus attach to the Achilles tendon, the strongest and thickest tendon in the entire human body.

The tendon originates approximately six inches above the heel, running down the middle of the leg to connect with the heel below the ankle.



Most of the Gastrocnemius muscle, together with each of the heads, are joined and inserted into the posterior surface of a broad membranous tendon.

Then it fuses with the soleus tendon to form the upper part of the tendocalcaneal. This broad tendon narrows until it reaches the calcaneus, where it expands again for insertion in the middle part of the posterior surface of the calcaneus.

Gastrocnemius muscle function

The Gastrocnemius with the soleus is the one that generates the main plantar flexion of the ankle joint.

This muscle is also a powerful knee flexor but cannot exert full power in both joints simultaneously. For example, when the knee is flexed, Gastrocnemius can not generate as much strength in the ankle.

The Gastrocnemius provides a significant propulsive force by running, walking, or jumping. This force is required to push the body towards the air, and together with the triceps surae, the point that the body needs to act is generated.


On the backside of the knee joint, the two large muscle bellies of the Gastrocnemius can be seen on each side of the upper portion of the calf.

The medial head projects higher and is lower than the lateral head. Both can be felt joining the tendinous union.

Lower down, in the calf, is the flattened tendocalcaneus that can be felt on the posterior surface of the calcaneus.

Possible actions with Gastrocnemio

  • Plantar flexion of the ankle in long sessions (note that the Gastrocnemius acts against the entire body daily).
  • Double or simple calf lift.
  • Straight leg jump.
  • Walk with ample or minimum length.
  • Passive dorsiflexion.
  • Lunge of body weight, and measure the leg straight back.

Treatment against weakness

To maintain the strong Gastrocnemius muscle, you can perform:

  • Weight lifting exercises or lifting weights.
  • Double and simple calf lift.
  • Weight-bearing exercises gradually progress into stability exercises by increasing the load, increasing repetitions, or varying the surface, for example, introducing a wobble board.
  • Sports-specific movement patterns such as running and jumping.


It must be taken into account that the Gastrocnemius muscle is the calf’s most superficial and prominent muscle.

It consists of two muscle regions, the medial head and the lateral head, which join the medial and lateral sides of the femur.

The heads of the Gastrocnemius muscle work together to plant the foot on the ankle and flex the leg in the knee; if it is affected by any injury, it can hinder the movement to walk, jog, jump, or even the flexion of the leg.

If the Gastrocnemius muscle is affected, recovery can be painful, and depending on the severity, it may even require surgical intervention.