Kinematic Analysis of Reverse Rotation DOLGAECHAGI in TAEKWONDO

Abstract

Purpose: The purpose of this study is to provide basic data for technical performance by analyzing and pre-senting differences in major kinematic factors in the take-off and flying phase and finally hitting phase with the national and non-national male demonstration team members as subjects. Method: The subjects of this study were six members of the national team and six members of the non-national team with more than three years of experience in the demonstration. Prior to the experiment, consent was obtained from each subject, and the Kinematic data was collected using 14 digital cameras. The statistical processing of this study used Excel 2018 to calculate the mean and standard deviation(M±SD) and statistical pro-grams to verify the differences in kinematic variables of the reverse rotation dolgaechagi. Shapiro-Wilk verifica-tion was performed to verify the normality of the collected data, and independent t-test and Mann-Whitney U test were performed to analyze the effect on kinematic parameters of the reverse rotation dolgaechagi of the national and non-national demonstration team members. The significance level of all statistics is set to α=.05. Results: Experiments have shown that in order to increase the completeness of reverse rotation dolgaechagi, the timing and momentum of the takeoff are required due to the nature of the motion in the takeoff and flying phases and that the maximum body center vertical direction, left and right direction, and forward-and-frontal COM must be balanced to contribute to the overall stability of the body after rapid rotation. Force ankle joint and knee joint and maximum bend on hip joint are needed to move upward and complete a perfect reverse rotation dolgaechagi. Conclusion: we found that, due to the nature of the reverse rotating dolgaechagi, the timing and momentum of the takeoff are needed to accurately secure the target position, and the role of balancing the body after a quick rotation and keeping the balance of the maximum body center vertical, left and right, and front and back are important factors to contribute to the stability of the entire body. We believe that further research is needed on the instantaneous speed of the body center, muscle activity needed, and analysis on the differences of the success and failure when reverse rotation is performed, which will greatly contribute to the improvement of the perfor-mance of the Taekwondo demonstration.