The changes of left and right leg movement on curved path during the latter half of 400m sprint

Abstract

The purpose of this study was to clarify the changes of left and right leg movement on curved path during the latter half of 400m sprint. Subjects were 8 male university sprinters (age 20.0 ± 1.2, height 1.75 ± 0.07m, weight 64.7 ± 6.2kg, personal best for 400m 50.98 ± 2.36sec). The subjects performed 400m sprint with maximal effort on the 1st lane in outdoor track. Trials were recorded and analyzed by two-dimensional motion analysis method focusing on 160-360m section during 400m sprint. This section was divided into five 40m phases (In straight , Beginning of curve, Center of curve, End of curve, and Out straight). The kinematics parameters were averaged for each phase and compared between the phases and between the left and right legs. The running velocity and the step frequency decreased significantly after the Center of curve in both legs. The stance time and the flight time increased significantly after the Center of curve in left leg and the right leg, respectively. Although, the step length of the left leg decreased significantly after the End of curve, the right leg showed no significant difference. Also, the stance distance of the left leg decreased significantly after the End of curve. Form these results, the present study demonstrated that the changes of movement and the factors affecting the decline in running velocity are different between left and right legs on curved path during the latter half of 400m sprint.

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

“…As a result, the error in the horizontal direction with respect to the markers installed at 2.5‐m intervals near the first hurdle was 0.019 m on average. It was lower than the error of a previous study (Ohnuma et al, 2014), and it was considered that the reconstruction of two dimensional coordinates in this study was sufficiently accurate.…”

“…Based on the calibration performed near the first hurdle, the coordinates of the measurement points in each frame during panning were calculated using the two‐ dimensional four‐point real length conversion method. Furthermore, based on the position of the marker inside the corner, the coordinates of the measurement points in each frame were converted to coordinates with the start point as a reference (Ohnuma et al, 2014). To confirm the accuracy of the two‐dimensional coordinate construction, the coordinates of the markers of each frame of the video were estimated, and errors with the coordinates of the actual markers were investigated.…”