【論文摘要】Relationship Between Movement Smoothness and Postural Stability During Single-Leg Stance in Poomsae Athletes

【論文摘要】跆拳道品勢運動員獨立步的動作流暢度與姿勢穩定度間關係

林重佑(Chung-You Lin) ； 戴偉國(Wei-Kuo Dai) ； 潘姿玲(Tzu-Ling Pan) ； 陳繪亘(Huei-Syuan Chen) ； 楊文傑(Wen-Chieh Yang)

《物理治療》 47卷2期 (2022/06) Pp. 109-110

https://doi.org/10.6215/FJPT.202206.O05

摘要

Background and Purpose: Poomsae is a set of defined defense-and-attack poses to show Taekwondo skills. Kumgang is the most difficult set due to multiple stability-demanding ＂crane-stance＂ (single-leg stance) pose. Movement smoothness and postural stability are key performance grading factors, though judged subjectively by the professional referee. Therefore, this study investigated the relationship between movement smoothness and postural stability during single-leg stance in Poomsae athletes. Methods: Thirteen athletes were recruited and performed Kumgang set. Joint angles of bilateral lower limbs and plantar pressure distribution were measured to evaluate movement smoothness and postural stability during the crane-stance poses, respectively. A crane-stance pose included a dynamic phase featuring the transition from double-leg stance to single-leg stance and spinning 90 degrees on the supporting leg, and a static phase featuring the maintenance of a steady single-leg stance. Movement smoothness was evaluated using log dimensionless jerk of hip, knee, and ankle of the supporting leg, with increasing negative values indicating more unsmooth angular accelerations and decelerations. Postural stability was measured using center-of-pressure (COP) travel distance (dynamic phase) and sway area (static phase). Pearson correlation was used to address the relationship between movement smoothness and postural stability. Results: In movement smoothness, log dimensionless jerk in the ankle (-12.2 ± 5.1) was significantly higher than knee (-6.2 ± 4.4, p ＜ 0.01) and hip (-4.7 ± 4.2, p ＜ 0.01). In the dynamic phase, log dimensionless jerk in the hip rotation was negatively correlated with COP travel distance (r = -0.43, p = 0.02). In the static phase, log dimensionless jerk in ankle inversion was negatively correlated with COP sway area (r = -0.62, p = 0.03). Conclusions: Our results showed that ankle overall dominated movement smoothness and postural stability during the crane-stance pose. However, the contribution of postural strategies varied from phase to phase. Specifically, in the dynamic phase, the shift of body weight was primarily determined by the hip; in the static phase, the maintenance of single-leg stance was primarily determined by the ankle. Clinical Relevance: This study offers TKD coaches and athletes an important insight into the strategy to improve Poomsae performance.