The Effect of Cop Errors on Joint Moments at Different Gait Velocities

The aim of this study was to investigate the effect of errors in the location of the center of pressure (5 and 10 mm) on joint moment uncertainties at different gait velocities (1.0, 1.5, and 2.0 m/s). Joint moments of five healthy young adults were calculated by inverse dynamics using the bottom-up approach. Results indicated that there is a linear relationship between errors in center of pressure and absolute joint moment uncertainties. The absolute moment peak uncertainties expressed on the anatomic reference frames decreased from distal to proximal joints, except for the abduction moments. There was an increase in moment uncertainty (up to 0.04 Nm/kg for the 10 mm error in the center of pressure) from the lower to higher gait velocity, although not for hip or knee abduction. Finally, depending on the plane of movement and the joint, relative uncertainties experienced variation between 5 and 31%, and the knee joint moments were the most affected.