Regulation of Stride Length During the Approach Run in the 400-M Hurdles

This research aims to clarify the stride adjustment in the approach of the 400-m hurdles, and to examine the relationship with 400-m hurdle performance. Seven male 400-m hurdlers volunteered for this study. Participants ran three times from the start to the second hurdle. The standard deviation of toe-hurdle distance and standard deviation of stride length at each step from the start to the first hurdle were calculated. The maximum value of the standard deviation of toe-hurdle distance was defined as the position at which the athlete starts stride adjustment. The relationships between each variable, 400-m hurdle personal best, and the ratio of 400-m hurdle personal best and 400-m running personal best (400 m/400-m hurdles) were examined. Results concluded that standard deviation of toe-hurdle distance gradually increased after the start, reached the maximum value in the latter half of the approach section, and then decreased until the takeoff. Standard deviation of stride length increased significantly from 4 steps before the takeoff. From these trends, it was suggested that athletes seemed to start stride adjustment from the middle stage to the latter half of the approach by sensing stride error accumulation in the middle of the approach. The strides immediately before the takeoff were markedly involved in stride adjustment. Furthermore, the stride adjustment technique to reduce maximum accumulation error of stride evaluated in the approach section was considered associated with the smooth running of the entire 400-m hurdle race.