The soleus muscle is a muscle in the posterior (back) compartment of the leg. It is located just behind the gastrocnemius muscle, which is the larger, more visible muscle in the calf. The soleus muscle helps to plantarflex the foot, which means it helps to point the toes downward. It also helps to stabilize the ankle joint and support the body’s weight when standing or walking.
The soleus muscle originates from the posterior surface of the tibia and fibula bones in the lower leg and inserts into the calcaneus (heel bone) via the Achilles tendon. It is a relatively long, thin muscle that lies deep to the gastrocnemius muscle. The soleus muscle is active when standing, walking, running, and jumping, and it plays an important role in activities that involve movement of the foot and ankle.
Injuries to the soleus muscle are relatively uncommon, but they can occur as a result of overuse or trauma. Symptoms of a soleus muscle injury may include pain, swelling, and difficulty moving the foot or ankle. Treatment may include rest, ice, physical therapy, and medications to reduce inflammation and pain. In severe cases, surgery may be necessary to repair the muscle.