Abstract
Gains in stump volume have been documented in transtibial amputees while walking in custom made undersized, total surfacebearing, vacuumassisted sockets (Board et al., 2001). These gains raised doubts as to whether the sockets were truly undersized and concerns that using an oversized socket with vacuumassist could lead to swelling, resulting, in discomfort or pain. The purposes of the present study were to determine if: (a) walking in a vacuumassisted socket causes the stump to retain or gain volume in excess of the available socket volume and (b) the resulting increase in stump volume with an oversized socket causes discomfort, pain, and/or the skin to redden. The results of this study showed the stump retained or gained volume in excess of the available socket volume while walking in vacuumassisted sockets of various sizes. The stump lost less volume than predicted, or gained volume, in undersized sockets. It also gained more volume than predicted in oversized sockets. No discomfort, pain, or skin reddening, resulting from the volume gain was reported by any of the subjects after walking in an oversized socket. This change in fluid balance towards a net gain supports the findings by Board et al. (2001) that vacuumassist ensures a good fit during the day in ambulatory transtibial traumatic amputees with mature stumps.