Does walking reduce venous pressure in your legs?

Yes: The squeezing of the calf muscles while walking will decrease the pressure in the veins by active compression. Other options to decrease the pressure is wearing compression hose and avoiding prolonged sitting.

Three Hearts (yes!): With regard to venous leg pressures the body can be described as having three hearts! the calf muscles and a system of valves make up numbers two and three. Once blood is in the legs physics tells us that the heart can't push or suck blood back up. When one calf contracts walking blood is squeezed up. When it stops (and the other calf contracts) the valves close holding blood against gravity.

Venous pressure: Walking does reduce venous pressure in the legs. This occurs because the calf muscle to a greater extent and the thigh and foot muscles to a lesser extent by contracting with walking increase the venous return back to the heart to decrease venous stasis and stagnation in the legs thus reducing the venous pressure in the legs.