A-25 The effects of changes in the alignment of running-specific prostheses on ground reaction force in transtibial amputation athletes

Abstract

Study Design: Cross-sectional study. Background: Studying how running-specific prostheses are set, can give amputee sprinters a competitive edge. Objective: Study how sagittal plane alignment changes in running-specific prostheses affect ground reaction forces (GRF). Method: Three transtibial amputees sprinted on a straight track using running-specific prosthetic feet. Sprint movements were recorded using a Vicon-MX system and floor reaction force measuring devices. The experiment level was set with normal alignment for test subjects as regularly recommended alignment (REG), 4° dorsiflexion from REG (DOR), and 4° plantarflexion from REG (PLA). Results: Impulse and average values of GRF showed significant differences in the vertical direction. Difference in foot contact time was insignificant. Conclusion: GRF is affected by sagittal plane alignment changes in running-specific prostheses. Transtibial amputee sprinters try to maintain optimal impulse by controlling the range of hip joint motion and the extension speed as alignment changes.