【論文摘要】Effect of Fatigue on Trunk Lateral Inclination During Roundhouse Kick in Taekwondo Athletes

【論文摘要】疲勞對於跆拳道運動員旋踢時軀幹側傾動作的影響

吳奕心(Yi-Xin Wu) ； 戴偉國(Wei-Kuo Dai) ； 陳繪亘(Huei-Syuan Chen) ； 楊文傑(Wen-Chieh Yang)

《物理治療》 45卷4期 (2020/12) Pp. 302-302

https://doi.org/10.6215/FJPT.202012.O09

摘要

Background and Purpose: The scoring rules in Taekwondo (TKD) encourage athletes to perform high kicks. A successful high kick requires both great mobility of trunk and hip joints, and delicate control of posture stability. However, the fatigue of proximal hip muscles may affect the conduction of high kicks, and athletes may adjust their trunk motion as compensation despite the current evidence are scarce. Therefore, this study aims to investigate the effect of fatigue on the trunk lateral inclination (inclination) during roundhouse kick in TKD athletes. Methods: Six TKD athletes (age: 19.67 ± 1.37 years, height: 168.75 ± 9.16 cm, weight: 58.59 ± 5.22 kg, 3 females) were recruited and underwent a simulated game test. The simulated game test included three 2-minute rounds, with a 1-minute inter-round break. In each round, participants were asked to conduct 30 roundhouse kicks according to the instructions displayed on the screen, and the instructions included the standing pose (right or left lead), kick leg (front or rear), and kick position (high, middle, and low). Trunk inclination and hip angles were measured using 4 inertial measurement units placed over lower thorax, sacrum, and bilateral thighs. An analysis of variance (ANOVA) with repeated measures was used to investigate the effect of fatigue (round 1, 2, and 3) and kick position (high, middle, and low) on trunk inclination and hip abduction during roundhouse kick. Results: All participants completed the simulated game test. In maximum trunk inclination, a significant position main effect (F = 27.41, p ＜ 0.01) and fatigue-position interaction was found (F = 9.72, p = 0.03). Generally, high kicks showed a significantly higher trunk inclination (22.48 ± 7.42°) than middle (15.22 ± 6.42°, p ＜ 0.01) and low (12.70 ± 7.83°, p ＜ 0.01) kicks. In addition, high kicks during the round 3 showed even higher trunk inclination (24.21 ± 6.02°) than those during the round 1 (21.03 ± 7.15°, p = 0.02) and round 2 (22.51 ± 6.82°, p = 0.03). In maximum hip abduction, a significant position main effect (F = 45.72, p ＜ 0.01) and fatigue-position interaction was found (F = 10.72, p = 0.02). Generally, high kicks showed a significantly higher hip abduction (41.22 ± 8.05°) than middle (37.31 ± 8.71°, p ＜ 0.01) and low kicks (35.71 ± 9.25°, p ＜ 0.01). However, high kicks during round 2 (40.25 ± 9.62°) and round 3 (38.82 ± 8.71°) showed lower hip abduction than those during round 1 (43.90 ± 10.62°, p = 0.03 and 0.02, respectively). Conclusion: Our results showed that high kicks require large trunk and hip mobility. Throughout the simulated game test, athletes showed a gradually increased trunk inclination and gradually decreased hip abduction, probably due to the development of fatigue in hip muscles. Clinical Relevance: The strategy adapted by TKD athletes to compensate hip muscle fatigue may maintain the kick height at the cost of postural instability despite the current evidence is scarce.