distance spikes in runners.

Various shoes are worn by distance runners throughout a train-ing season. This study measured the differences in ground reac-tion forces between running shoes, racing flats, and distance spikes in order to provide information about the potential effects of footwear on injury risk in highly competitive runners. Ten male and ten female intercollegiate distance runners ran across a force plate at 6.7 m·s-1 (for males) and 5.7 m·s-1 (for females) in each of the three types of shoes. To control for differences in foot strike, only subjects who exhibited a heel strike were in-cluded in the data analysis. Two repeated-measures ANOVAs with Tukey’s post-hoc tests (p < 0.05) were used to detect dif-ferences in shoe types among males and females. For the males, loading rate, peak vertical impact force and peak braking forces were significantly greater in flats and spikes compared to run-ning shoes. Vertical stiffness in spikes was also significantly greater than in running shoes. Females had significantly shorter stance times and greater maximum propulsion forces in racing flats compared to running shoes. Changing footwear between the shoes used in this study alters the loads placed on the body. Care should be taken as athletes enter different phases of train-ing where different footwear is required. Injury risk may be increased since the body may not be accustomed to the differ-ences in force, stance time, and vertical stiffness