武術套路太極拳騰空擺蓮360°接提膝獨立之動作分析

Motion Analysis of Taijiquan Lotus Kick with 360° Twist Followed by One Knee Raised Landing

目的：探究耐力跑運動中，跑者在疲勞前、後下肢的撞擊力量、著地型態，及下肢運動學特性等運動生物力學現象是否有所差異。方法：以大專體育系有慢跑習慣之男性學生10名為受試對象。兩塊測力板與八台光學攝影機同步擷取受試者於實驗跑道上跑步的資料。每位受試者先進行跑步的前測資料收集，隨後便於跑步機上執行疲勞操弄，接著進行跑步的後測資料收集。以The Motion Monitor動作分析軟體獲得跑步的下肢運動學參數，以及測力板參數，並進一步計算著地型態指數。以相依樣本T檢定，比較各參數在前測與後測間是否有顯著差異，統計顯著水準訂為α = .05。結果：疲勞前、後跑步的速度、步幅、步頻、觸地時間分配，與地面反作用力皆沒有顯著差異。疲勞後觸地瞬間的膝關節屈曲角度會增大，且增大著地期間的膝關節最大外翻角度，此外，觸地瞬間的著地型態指數變小。結論：疲勞後，受試者會增大觸地瞬間的膝關節屈曲，此補償機制或許使得著地的撞擊力不會增大，但著地期間膝關節最大外翻角度在疲勞後會增大，此應與跑步傷害的發生風險有所關聯，此外，疲勞後足掌觸地的位置會移向足跟處，故著地型態指數或許可作為判斷疲勞的依據。

 

Purpose: To explore the factors that may affect the successful rate of performing lotus kick with 360˚ twist followed by one knee raised landing in taijiquan athletes. Methods: Eight college level of taijiquan athletes participated in this study. A high speed infrared camera system was synchronized with a force plate for data collection and motion analysis. Each athlete required to perform 10 times of the designated movement. Whether each of the performance was successful or not was decided by three national-level referees. Biomechanical variables analyzed in this study included jump height, jump power, time difference between the moment of slamming the kicking leg and the moment of center of mass (COM) reaching the highest point, vertical displacement of the COM, direction and speed of the kicking leg, horizontal displacement of the COM after landing, and the time difference between the moments of the hip and knee joint movement start. Mann-Whitney U tests were used to compare the differences in demographic data and the variability of each biomechanical variable between 4 athletes with higher successful rate and 4 athletes with lower successful rate. Due to the sample size in this study was small, each biomechanical variable was categorized into several levels. Chi-square tests were conducted to examine whether there were significant relationships between successful (33 times)/unsuccessful (47 times) jumps and the count distribution of different levels in each biomechanical variable. Results: The group with higher successful rate had heavier body weight and longer practicing experience. They also had less variability in the variables of jump height, time difference between the moment of slamming the kicking leg and the moment of COM reaching the highest point, and direction of the kicking leg. Chi-square tests revealed that successful jumps had greater jump height than unsuccessful jumps. Conclusion: In addition to the body weight and practicing experience that may affect the successful rate of performing the lotus kick in this study, taijiquan athletes can try to increase their jump height and to improve the consistency of their own jump movements to increase their successful rate.