Shock absorbers for vascular trans-tibial amputees in environmental situations seem more efficient on comfort than on oxygen consumption

Abstract : Objective To evaluate, in an environmental situation, the effects of a shock absorber on oxygen consumption and on prosthesis comfort in people with vascular trans-tibial amputation. Methods Thirteen patients (average age: 71 years ± 9), with unilateral vascular trans-tibial amputation since 10 months ago, used a shock absorber on the usual prosthesis. The patients were evaluated on a distance of 10 meters, on an outside walking track and on stairs with and without an absorber within an interval of one week. We measured oxygen consumption (VO2) and heart rate. VO2 was measured in environmental situations by portable system VmaxST sensor medic®. The evaluation of the prosthesis' comfort has been made with a questionnaire, the pain with a visual analogic rate scale. Results An overconsumption appeared during the test of the 10 meters for a patients fitted with a SACH foot. A significant decrease of the VO2 was observed during the going up. Shock absorber allowed a comfort improvement notably during the going up and down stairs respectively for 78 and 67% of the patients. These ones noticed a real decrease, and even a disappearance of the stump leaning pains after fitting up the absorber. Conclusion The improvement of prosthesis comfort and of pain are important for this type of patients. The energetic interest of shock absorber was only observed during the stairs test.