INTRA-STRIDE BELT-SPEED VARIATION AFFECTS TREADMILL LOCOMOTION

For overground and treadmill locomotion to be mechanically similar, it is required that the belt speed of the treadmill is constant and the same to that of overground locomotion. Variation of the belt speed dur ing a stride causes exchange of energy between the subject and the tre admill. This might be the cause of different kinematic patterns betwee n overground and treadmill locomotion, which have been reported in lit erature. The aim of this study was to investigate whether the intra-st ride belt-speed is variable, and whether differences in kinematic patt erns can be attributed to these variations. Nine subjects walked and r an overground and on two treadmills that were differently susceptible to subjects' braking and accelerating forces. It was found that the sp eed variations during treadmill locomotion affect the kinematic parame ters significantly. The amount of intra-stride belt-speed variation wa s found to depend on the power of the treadmill and the mass of the su bject. (C) 1998 Elsevier Science B.V.