A noninvasive plethysmographic method for evaluation of the musculovenous pump in the lower extremities.
A refinement of plethysmographic musculovenous pump evaluation, with methodologic improvements, is presented. By using a double strain-gauge and knee-bendings, measurement can be made at malleolus level. Use of knee-bending instead of heel-lifting reduced the coefficient of variation in day-to-day determinations from 40% to 12%. A total of 20 knee-bends was found to be ideal for measurements, as a steady state was reached and secondary muscular hyperemia was avoided. The parameters venous return time and expelled volume increased with distal application of strain-gauge, and this must be taken into account in comparisons against reference values obtained with other methods. The coefficient of variation for duplicate determinations with the present method was c. 12% for normal controls and also for patients with varicosity. Reference values derived from 40 normal legs and 68 varicose legs are presented. The investigation demonstrated improvement of a noninvasive method, increasing its reliability for clinical and research purposes.
D000328:Adult; D000368:Aged; D001696:Biomechanical Phenomena; D005260:Female; D006365:Heel / Q000502:physiology; D006801:Humans; D007717:Knee / Q000502:physiology; D007866:Leg; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction; D009132:Muscles / Q000098:blood supply*; D005082:Physical Exertion; D010991:Plethysmography / Q000379:methods*; D011187:Posture; D013696:Temperature; D014648:Varicose Veins / Q000503:physiopathology; D014690:Venous Pressure