It is not known whether the effect of Foot Pumps is enhanced by simultaneous use of graduated compression stockings (GCS) (by controlling calf compliance) or hindered (by restricting preload).

The peak velocity in the popliteal vein was measured in twenty volunteers with duplex ultrasound at rest with the legs flat, foot-up and foot-down; it was then measured when the AV Impulse was activated. These measurements were each performed with and without graduated compression stockings. Data were analysed using Wilcoxon Rank Sum test.

In each position of the leg (flat, foot-up and foot-down), the Peak venous velocity was greater if GCS were not used in comparison with the peak velocity if stockings were used.

There was no significant difference in resting velocity with the foot flat, foot down or foot up without stockings or with stockings.

Various studies have shown the efficacy of foot pumps in reducing the incidence of DVT in patients with joint replacements and hip fractures. They do not cause soft tissue side effects and are well tolerated. The value of GCS in orthopaedic surgery is uncertain, although in other surgical specialities they seem to be effective. Stockings, by reducing the capacitance of vessels in the foot reduce the amount of blood available for expulsion by the foot pumps.

Nevertheless, our study presents physiological evidence for the hypothesis that, for optimum benefit, stockings should not be used simultaneously with Foot Pumps.