Soleus Muscle Gastrocnemius Muscle Adductor Muscle Semitendinosus Muscle Biceps Femoris Muscle Iliotibial Tract Gluteus Medius Muscle Gluteus Maximus Muscle Peroneus Longus Muscle Extensor Digitorum Longus Muscle Tibialis Anterior Muscle Pectineus Muscle Vastus Lateralis Muscle Vastus Medialis Muscle Rectus Femoris Muscle Sartorius Muscle Gracilis Muscle Adductor Longus Muscle
It extends about 2.8 to 3.9 inches down from the knee and lies between the gastrocnemius and the soleus. The gastrocnemius branches at the top behind the knee. These two branches are known as the medial and lateral heads.
During walking the gastrocnemius flexes and when the knee bends it causes the femur (thigh bone) to be pulled toward the tibia in the lower leg which causes the knee to bend. The achilles tendon on the heel is the strongest tendon in the body. Both the gastrocnemius and the soleus join the achilles tendon. The top of the tendon starts about 5.9 inches above the heel and runs centerline to the heel below the ankle. It is important to the following functions of running, walking and jumping.
Anatomy of the Gastrocnemius Muscle:
Two heads called the lateral head and the medial head
The lateral head originates from the attachment to the lateral condyle of the femur.
The medial head originates from the attachment to the medial condyle of the femur.
The insertion of the gastrocnemius muscle is onto the posterior surface of the calcaneus (heel bone).
Before insertion to the heel bone the gastrocnemius muscle forms a common tendon with the soleus muscle called the calcaneal tendon or Achilles Tendon. Although the soleus muscle is separately named it is considered by some anatomists to be a single muscle with the gastrocnemius muscle. The name in such instances is called the triceps surae or “calf muscle” and this is because they are sharing a common insertion to their ends at the Achilles Tendon. Frequently there is a sesamoid bone called the “fabella” in the lateral head of the gastrocnemius muscle.