Differences in kick-leg kinematics in various side-kick heights.

This study aims to explore the variation of lower extremity kinematic characteristics when elite taekwondo athletes perform the side-kick on protective gear placed at various heights. Twenty distinguished male national athletes were recruited and were asked to kick targets at three different heights adjusted according to their body height. A three-dimensional (3D) motion capture system was used to collect kinematic data. Kinematic parameters differences in the side-kick at three different heights were analyzed by using a one-way ANOVA (p < .05). The results revealed significant differences in the peak linear velocities of the pelvis, hip, knee, ankle, and centre of gravity of the foot during the leg-lifting phase (p < .05). Significant differences between heights were noted in the maximum angle of pelvis left tilting and hip abduction in both phases. In addition, the maximum angular velocities of pelvis left tilting and hip internal rotation were only different in the leg-lifting phase. This study found that, to kick at a higher target, athletes increase the linear velocities of their pelvis and all lower extremity joints of attacking leg in the leg-lifting phase; however, they only increase rotational variables on the proximal segment at the peak angle of the pelvis (left tilting) and hip (abduction and internal rotation) in the same phase. As an application in actual competitions, according to the opponent's body height, athletes can adjust both linear and rotational velocities of their proximal segements (pelvis and hip) and deliver into distal segements (knee, ankle, foot) linear velocity to perform accurate and rapid kicks.

Kinematic and kinetic demands on better roundhouse kick performances.

The roundhouse kick is one of the most widely applied techniques in a taekwondo competition. Because the scoring system of taekwondo has been changed, the skill of roundhouse kick has been affected. Therefore, coaches and athletes are attempting to better understand how to control the movement of the kick to gain points more effectively. The aim of this study was to investigate the differences in the biomechanical characteristics between the roundhouse kicks with higher and lower impact magnitude using an electronic body protector. Eighteen elite college Taekwondo athletes participated in this study. A motion capture system measured the kinematics data of the kicking leg. The results indicated that elite athletes can obtain a high-impact index of the electrical body protector through increasing the peak linear velocity of shank, even with the same foot velocity level. In regard to kinetic skills, the roundhouse kicks a high impact. The velocity of proximal kicking limb could predominantly contribute to the powerful roundhouse kicks to achieve the high-impact force for electrical body protector. Moreover, when the kick cannot be effectively scored during the game, coaches and masters should consider adjusting to increase the velocity of proximal kicking.