[Venous plethysmography in a sitting position].

We studied the venous capacity of the lower limbs by strain gauge plethysmography during venous occlusion (delta v60) and by a dependency test (delta v postural) (from the supine to the sitting position). We were also interested by the performance of the calf musculovenous pump, assessed in two positions: sitting and standing (delta v exercise). The volume changes are increasing when we consider limbs with sequelae of deep vein thrombosis, normal lower limbs and extremities with primary varices. delta v60: 2.13%, 2.84%, 4.24%; p less than 0.01. delta v postural: 1.32%, 1.94%, 3.66%; p less than 0.01. delta v exercise: 0.48%, 1.47%, 2.09%; p less than 0.01. The study of the expelled volume during calf muscle exercise is easier in the sitting than in the standing position and it leads to a better discrimination between normal limbs and limbs suffering from sequelae of deep vein thrombosis. The dependency test with measurement of the venous capacity when going from the supine to the sitting position (with the leg dependent) and the assessment of the calf muscles pump, also in the sitting position, are the basis of a simple approach to the quantitation of venous insufficiency.