(Georgia Institute of Technology, 2008-04-23)
Balogh, Austin
The main goal of transtibial prosthesis suspension is to minimize residual limb motion
within the prosthesis. Poor suspension can lead to negative outcomes in prosthetic
treatment, and may have a great impact on the mobility of an amputee. Prior research on
this topic has focused on measuring pistoning by radiographic imaging of the residual
limb in positions of simulated gait. Several suspension methods have previously been
compared, but there is limited research on elevated vacuum suspension method. The
purpose of this study is to investigate the effect of elevated vacuum suspension, standard
suction with an expulsion valve, and knee sleeve suspension on residual limb pistoning.
Five persons with unilateral transtibial amputations were recruited to participate in this
study. Each subject was fit with a custom prosthesis that was easily converted between
suspension methods. Dual energy x-ray absorptiometry DEXA scans were taken of the
subjects' limb in the prosthesis under three different loading conditions to determine the
amount of pistoning. Pistoning was measured as the difference between the half body
weight loaded condition and the 44.5 N distraction force condition for each suspension.
There was no statistical significance between the suspension methods determined using a
repeated measures within subjects ANOVA. Future research should include addition of
more subjects to increase the power and significance of this work. Another logical step
would focus on measuring pistoning during dynamic activity.