Venous pressure in the saphenous vein near the ankle during changes in posture and exercise at different ambient temperatures.

The venous pressure in the saphenous vein at the ankle was measured in ten healthy subjects (5 men, 5 women) aged 19-33 years during supine posture, orthostasis and cycle ergometer exercise (50 W, 50 rpm). Measurements were made at 20, 28 and 36 degrees C at 50% relative humidity. A custom-built setup consisting of two pressure transducers and a differential amplifier was used to compensate for the hydrostatic effects, temperature influences and movement artefacts that disturbed the pressure measurements.

Volume changes in the lower leg during quiet standing and cycling exercise at different ambient temperatures.

The purpose of this study was to investigate whether ambient temperature influences both the rate of leg swelling during orthostasis and the oedema-preventing effect of the skeletal muscle pump. Using mercury-in-rubber strain gauges, volume changes were measured in the calf (n = 34) and near the ankle (n = 24) in healthy volunteers aged 19-33 years. Measurements were performed during 12 min of motionless standing in an upright posture and during 17 min of cycle exercise at intensities of 50 W and a pedalling rate of 50 rpm.

Measurements of volume changes and venous pressure in the human lower leg during walking and running.

This study investigates whether walking or running prevents the formation of edema in the lower leg. In 18 volunteers changes in calf volume were measured using strain gauge plethysmography during slow (3 km/h) and fast (6 km/h) walking or running (10 km/h) on a treadmill for 20 min each. Venous pressure was measured in a superficial vein near the ankle.

Slow volume changes in calf and thigh during cycle ergometer exercise.

To study the transcapillary fluid movements in the human lower limb in the upright body position and during muscle exercise, the slow changes in thigh and calf volumes were measured by mercury-in-rubber-strain gauge plethysmography. Measurements were carried out on 20 healthy volunteers while sitting, standing and doing cycle ergometer exercise at intensities of 50 and 100-W. A plethysmographic recording of slow extravascular volume changes during muscle exercise was possible because movement artefacts were eliminated by low-pass filtering.

On the edema-preventing effect of the calf muscle pump.

During motionless standing an increased hydrostatic pressure leads to increased transcapillary fluid filtration into the interstitial space of the tissues of the lower extremities. The resulting changes in calf volume were measured using a mercury-in-silastic strain gauge. Following a change in body posture from lying to standing or sitting a two-stage change in calf volume was observed.