Plethysmographic Measurement of Venous Flow Resistance and Venous Capacity in the Human Leg. Part One: Method

Abstract

This report presents a study of the methodological aspects of the measurement of venous flow resistance ( Rv) and venous capacity (C10) in human legs as measured by strain-gauge plethysmography. The measurements are reproduceable within 10%, in subjects who are well-acclimatized to a room temperature of 28–30 °C. In measurements at the calf, extension of the knee joint may increase Rv by hundreds of percents, while high passive calf muscle tension may be associated with a decrease in Rv and an increase in C10. Inadequate acclimatization may increase Rv and decrease C10, notably in measurements at the foot. The determinants for Rv and C10 are discussed.