Soleus

The soleus (Latin: musculus soleus) is a superficial muscle of the posterior compartment of the leg. It stretches between the tibia, fibula and calcaneus. Together with the gastrocnemius, the soleus forms a muscle complex called the triceps surae.

Origin

The soleus muscle originates from the head and upper third of the posterior border of the fibula, soleal line and middle third of the medial border of the tibia and tendinous arch between the fibula and tibia.

Insertion

The soleus joins with the gastrocnemius, and both muscles form a common tendon called the calcaneal or Achilles tendon that inserts on the posterior surface of the calcaneus.

Action

The soleus muscle provides the foot plantar flexion at the talocrural (ankle) joint. It also plays an important role in maintaining the standing pose.

Innervation

The soleus is innervated by the tibial nerve (S1 - S2) - a terminal branch of the sciatic nerve.

Blood supply

The soleus muscle receives arterial blood supply from the sural arteries of the popliteal artery, peroneal (fibular) artery and branches of the posterior tibial artery.