Gastrocnemius

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.

• Attachments:
  • 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).

By TeachMeSeries Ltd (2025)

Fig 1
The muscles in the superficial layer of the posterior leg. The body of the gastrocnemius has been cut away to expose the underlying musculature.