Why Calf Muscles Called The "Second Heart"

Have you ever thought, why soldiers standing in attention sometimes faint? Why sales-people or cashiers, especially those who predominantly stand most of the day, develop varicose veins over a period of time? Similarly, sitting without moving the leg muscles for long duration (flight etc.) causes swelling in the legs?

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Tightening and relaxing the calf muscles can prevent the pooling of the blood. The role of soleus muscles or your calves is critical in returning blood to the heart that they are referred to as the "secondary hearts" of the body.

What Does Your Calf Muscle Do?