[Physiology of venous circulation]

The venous system becomes deformed and distended under the effect of neighboring tissues and hydrostatic pressure. It is thus under a constant threat of stasis. While lying-down at rest, the venous blood is propulsed by means of the pressure gradient maintained by the vis a tergo and the vis a fronte, modulated by the parietal tonus. While standing and stationary, decompensation occurs despite the bulbar reflexes, despite lymphatic resorption and despite the counter-pressure of the perivenous tissues. However, muscular activity and especially walking at a steady pace, restores the resorption of the interstitial liquids, tanks particularly to the musculovascular synergy or the peripheral heart.