Effectiveness of elevated vacuum and suction prosthetic suspension systems in managing daily residual limb fluid volume change in people with transtibial amputation.

Only 12 participants were tested, and the small sample and non-normal data required non-parametric comparisons. The order of conditions was fixed, with elevated vacuum tested before suction suspension, so an order effect could not be evaluated. All participants were existing elevated vacuum users, and different EV socket designs were used. The suction suspension condition was simulated by deactivating the elevated vacuum pump, which may not represent a typical suction socket because the pump added weight and the socket had elevated-vacuum-specific relief features. Vacuum pressures were set by the prosthetist to the highest available setting, so intermediate settings were not tested. Participants were at least 18 months after amputation and classified as K-2 or higher. Protocol deviations affected some data: a pump malfunction required Participant 6 to reset the pump and change the reference point, and bioimpedance noise required modified processing for Participant 9's posterior channel. Two participants reported consuming caffeine on the first test day and repeated it on the second day. Comorbidities such as diabetes and cardiovascular issues may have affected results, although none reported peripheral vascular disease.

Do not conclude that elevated vacuum is better than suction suspension for overall daily residual limb volume management. The overall rate of fluid volume change was not significantly different between conditions, and the positive posterior finding occurred only in the final cycle.