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Gastrocnemius Muscle Anatomy: Origin, Insertion, Action

Origin:  Medial head: Posterior part of the medial condyle and the adjoining part of the femur.
Lateral head: The lateral condyle and the adjoining part of the femur.
Insertion:  The calcaneus via the Achilles tendon
Actions: Plantarflexion of the foot at the ankle, assists with flexion of the leg at the knee
Innervation: Tibial nerve S1, S2
Blood Supply: Branches from the posterior tibial and popliteal arteries
Image showing the gastrocnemius muscle origin and insertion

Looking for pain and symptom information? Visit the Gastrocnemius Pain Page.

Primary Actions of the Gastrocnemius Muscle

  1. Plantarflexion of the foot at the ankle

Agonists:  Soleus

Antagonists: Tibialis Anterior

Plantaris, tibialis posterior, peroneus longus, flexor hallucis longus, and flexor digitorum longus assist with plantarflexion of the foot at the ankle.

Secondary Actions of the Gastrocnemius Muscle

  1. Assists with flexion of the knee

Agonists: 

  • Biceps Femoris (long and short heads)
  • Semitendinosus
  • Semimembranosus

Antagonists:

  • Vastus Lateralis
  • Vastus Medialis
  • Vastus Intermedius
  • Rectus Femoris

Gracilis, sartorius, popliteus, and plantaris also assist with flexion of the knee.