soleus /sō″lē·əs/ [L, solea, sole of foot] , one of three superficial posterior muscles of the leg. It is a broad, flat muscle lying just under the gastrocnemius. The fibers of the soleus merge near the middle of the leg with those of the gastrocnemius to form the tendo calcaneus, which inserts into the calcaneus of the foot. The soleus plantar flexes the foot. Compare gastrocnemius, plantaris.
