The Feasibility of Underwater Computerised Strain Gauge Plethysmography and the Effects of Hydrostatic Pressure on the Leg Venous Haemodynamics

Background: Strain gauge plethysmography (SGP) is employed to evaluate venous drainage of the lower leg. Methods: In this study, SGP was used to evaluate the effects of the hydrostatic pressure (HP) of water on venous volume (VV), expelled volume, and ejection fraction (EF) in 22 healthy legs before and during immersion in water. Results: HP reduced VV by 100% and even more during underwater (UW) exercise, making calculation of the UW EF possible. Discussion: UW SGP is feasible and indicates that HP improves venous haemodynamics. This study suggests that including UW leg exercise in the rehabilitation protocols of patients with chronic venous disease may be useful. Keywords: Strain gauge plethysmography, Underwater compression, Underwater ejection fraction, Underwater venous volume.