How do skeletal muscle contractions help return blood through veins?

Skeletal muscle contractions play a vital role in returning blood to the heart, particularly when blood must move against gravity in the limbs. As surrounding skeletal muscles contract during movement, they compress the veins, which physically squeezes and propels the blood forward toward the heart.12

Because veins have thinner walls and lower blood pressure than arteries, they rely on this "muscle pump" mechanism to maintain efficient circulation. To ensure this blood flow remains unidirectional, veins contain one-way valves that prevent the blood from flowing backward between muscle contractions. This process, combined with pressure changes in the chest during breathing, ensures that blood is effectively returned to the heart.21