Blood flow velocity was measured in the femoral veins of ten inactive recumbent subjects in order to determine the effect of elastic stocking compression on venous flow. A noninvasive Doppler ultrasound technique was used to measure blood flow velocity. Results of these studies indicate that elastic stockings increase femoral venous flow velocity during periods of compression up to three hours. This increase in blood flow velocity persists for up to 30 minutes after removal of stockings. Compression reduces the fluctuation effect of respirations on venous flow, resulting in a more constant flow. These findings indicate that elastic compression of the lower extremities produces effects (increased venous flow velocity and decreased venous pooling) that may reduce the occurrence of venous thrombosis.
Sigel B, Edelstein AL, Felix WR, Memhardt CR. Compression of the Deep Venous System of the Lower Leg During Inactive Recumbency. Arch Surg. 1973;106(1):38-43. doi:10.1001/archsurg.1973.01350130040009