The effect of SACH and Dynamic-Response Feet on Shock Absorption, Ground Reaction Force and Vertical Impulse Variables in Stance Phase of Running of Individuals with Unilateral Transtibial Amputees

Transtibial amputees usually use one specific prosthetic foot to locomate normally. Biomechanical Characteristics of unilateral transtibial amputees with various types of prosthetic feet have been studied during running. Although SACH and Dynamic-Response feet manufactured by Otto Bock are the most components used in Iran, examining function of these feet is less considered in locomotion activity.The purpose of this study was to survey the effect of SACH and Dynamic Response feet on several kinetic variables in stance phase of running in individuals with unilateral transtibial amputation. Eight male unilateral transtibial amputees were participated in this experimental study. They agreed to sign the consent form. Each subject runs in 12-meter walkway three times at a speed of 2.5 meters per second. Kistler force plate and three-dimensional motion analysis VICON system were used to collect kinetic data and control running speed, respectively. Repeated measures of ANOVA and Friedman test were used to analyze the data based on normality (P<0.05). The residual leg of individuals with unilateral transtibial amputees did not show shock absorption index(peak vertical ground reaction force during heel contact). Ground reaction force were significantly different between the SACH, Dynamic-Response and selected feet (p<0/001). SACH feet had a greater ground reaction force than Dynamic-Response and selectd feet (p<0/001). There was no statistical difference vertical impulse between any kind of feet (p=0/38). The results of study showed that ground reaction force with SACH feet was greater than Dynamic response feet and can be concluded that the risk of Patellofemoral pain syndrome may be increased in amputated leg.