A Study of Venous Return from the Leg during Exercise

Abstract

Bi-directional ultrasound velocity detector tracings were made of venous blood flow through the popliteal vein in the following situations: (1) walking normally; (2) walking in place; (3) sitting, foot on floor, with rhythmic plantar and dorsi-flexion; (4) sitting, foot on a treadle device requiring 20 degrees of plantar-flexion and 20 degrees of dorsi-flexion to complete a cycle; (5) using the treadle device while in recumbent position, and (6) pushing the foot in plantar flexion against a pedal equipped with a spring resistance. These studies show that active walking, which consists of both plantar flexion and dorsi-flexion, produces cephalad return of venous blood from the foot and leg. When the walking cycle is accompanied by weight bearing, plantar flexion produces a greater blood velocity. However, when there is no weight bearing, dorsi-flexion produces a greater blood velocity than plantar flexion. Therefore, when not bearing weight on the foot, a full range of dorsi-flexion as well as a full range of plantar flexion is essential to utilizing maximum efficiency of the lower extremity muscle pump.