Effects of hurdle height on lower limb joint kinematics and kinetics of male trainee sprinters during hurdle jumps.

Hurdle jumps are frequently practiced in the field of sports training. The present study aimed to clarify the effect of hurdle heights on jumping height and joint kinematics, and kinetics during hurdle jumps. Ten male Japanese trainee sprinters performed at three heights (0.76, 0.91 and 1.06 m) of hurdle jumps and maximum countermovement jump (CMJ). Sagittal plane kinematics and ground reaction force were measured. Jump height significantly increased with hurdle heights (η_p² = 0.65), but the difference in jump heights was small as compared to the difference in the hurdle heights. The contact time and mechanical work of the lower limb joints did not differ between different hurdle heights. The minimal angles of the knee (η_p²  = 0.47) and hip (η_p²  = 0.70) joints during the flight phase significantly decreased with higher hurdle heights. The load characteristics of the lower limb joint with higher hurdle heights would be similar to those with lower hurdle heights. In higher hurdle heights, since the increase in jump height was smaller than the increase in hurdle height, the legs were more flexed to clear the hurdle. Therefore, the hurdle height which is similar to the maximum CMJ height would be appropriate as a training load.