The soleus is a muscle located in the lower leg, beneath the larger gastrocnemius muscle. It plays a crucial role in walking, running, and maintaining balance by helping to lift the heel off the ground. The soleus is primarily responsible for plantar flexion, which is the movement that points the toes downward. This muscle is particularly important for activities that require endurance, such as long-distance running and standing for extended periods. It is often engaged during activities that involve pushing off the ground, making it essential for athletes and individuals who are active in sports like basketball and soccer.