The soleus (also soleus muscle, latin: musculus soleus) is a powerful muscle of the posterior group of the lower leg muscles originating from the head of fibula and soleal line of tibia and inserting onto the calcaneal tuberosity of calcaneus altogether with the gastrocnemius.
The soleus originates from the head of the fibula and the soleal line of the tibia.
The soleus joins with the aponeuroses of the gastrocnemius, forming the calcaneal tendon or Achilles tendon that inserts onto the calcaneal tuberosity.
The functions of the soleus are flexion, supination and adduction of the foot. It also plays an important role in maintaining the standing pose.
The soleus is innervated by the tibial nerve, which is a terminal branch of the sciatic nerve.