EFFECTS OF FATIGUE ON THE GROUND REACTION FORCES AND LEG KINEMATICS IN ALL-OUT 600 METERS RUNNING

Abstract

The purpose of this study was to investigate effects of fatigue on the ground reaction forces and leg kinematics during all-out 600m running, which was performed by eight male middle-distance runners. Their running motion was videotaped (300Hz) and the ground reaction forces were measured (500Hz) at the 150m and 550m marks of the 600m running. From the 150m to 550m mark, running speed significantly decreased (p<0.001) while the 2nd half of the support time significantly increased (p<0.01). During the 2nd half of the support phase, the horizontal impulse (p<0.05) and the average force (p<0.001) of the ground reaction force significantly decreased. Furthermore the average angular velocity of the support shank significantly correlated with the horizontal average force (r=-0.811, p<0.001), the ratio between the vertical and horizontal average force (r=0.803, p<0.001). Therefore it is likely to be one of the important techniques to maintain large forward lean and angular velocity of the support shank during the support phase in the final stage of the middle-distance running races.