The gastrocnemius is a muscle within the superficial compartment of the posterior leg. It has medial and lateral heads and forms the characteristic “calf” shape of the leg.
- The lateral head originates from the lateral femoral condyle. The medial head originates from the medial femoral condyle.
- The two heads combine to form a single muscle belly.
- Distally, the muscle belly converges with the soleus muscle to form the calcaneal tendon. This inserts onto the calcaneus.
- Actions: Plantarflexion at the ankle joint and flexion at the knee joint.
- Innervation: Tibial nerve.
- Blood Supply: Medial and lateral sural arteries (branches of the popliteal artery).