Triceps surae

The triceps surae (Latin: musculus triceps surae) is a group of large muscles located in the posterior compartment of the leg. It consists of two superficial posterior leg muscles - gastrocnemius and soleus. Both muscles form the main mass of the calf. Along with the plantaris, the triceps surae is classified as the superficial flexor muscle.

The gastrocnemius covers the soleus and contains two heads - medial and lateral. Each of the muscles has a different site of origin, but both join together and form a common tendon approximately in the middle third of the leg. The tendon is called the Achilles or calcaneal tendon, and it inserts on the calcaneus.

The triceps surae provides foot plantar flexion at the talocrural (ankle) joint, while the gastrocnemius also is responsible for the flexion of the leg at the knee joint.