A haemodynamic study of the physiological mechanisms of the venous pump in the healthy human foot.

Presented is a physiological study of the plantar venous plexus in the context of venous return. It is accepted that the plantar venous plexus acts as a peripheral venous pump, capable of emptying blood from the foot into the posterior tibial veins. Controversy still exists, however, over the precise physiological mechanism which is responsible for completely emptying the deep plantar veins of the foot. This study was designed to investigate whether weight bearing or muscular contraction was the dominant mechanism involved. This was achieved by comparing blood flow measurements taken from the posterior tibial and popliteal veins while performing specific foot exercises. Measurements were taken using Doppler ultrasound. Neuromuscular electrical stimulation was also used to study the blood flow obtained by artificially inducing contraction of the plantar venous plexus.