Author: Dr Peter de Souza
Last modified: 19 November 2022

The gastrocnemius is one of the muscles within the superficial group within the posterior compartment of the leg. The muscle fibres of the gastrocnemius blend with the soleus deep to it distally to form the calcaneal tendon which inserts on the calcaneus.

The leg is comprised of anterior, lateral and posterior compartments. The posterior (flexor) compartment consists of two groups of muscles: a superficial group and a deep group, which are separated by a deep fascial layer.

Muscles of the superficial group within the posterior compartment of the leg

Muscles of the deep group within the posterior compartment of the leg

Origin

  • Medial head: posterior aspect of medial femoral condyle
  • Lateral head: posterior aspect of lateral femoral condyle

Insertion

  •  Calcaneal tendon to posterior surface of calcaneus

Action

  • Plantarflexes foot
  • Flexes knee

Innervation

  • Tibial nerve; S1,S2

Blood Supply

  • Sural branches of popliteal artery