中老年人與老年人隨著年齡慢慢增加，身體機能也慢慢衰退，研究指出65歲以上的老年人，身體的肌肉量會以每年1~2%的速度流失，因此造成下肢機能的衰退，進而影響到日常功能性動作的完成，也會增加日常生活中跌倒的風險，而跌倒此一因子對老年人來說具有非常大的影響，可能造成長期臥床，更有甚者就此不起。預防勝於治療的觀念慢慢廣為大眾所接受，欲降低老年人生活中功能性的退化，研究指出適度的運動可減緩老年人肌肉退化，而太極拳因結合吐納呼吸、拉筋伸展與可自由調整運動強度的特性，為適合中老年人與老年人的運動。過去研究中老年人與老年人太極拳的相關研究中，較缺乏各關節力矩與功率的相關研究，且立定垂直跳常被用來做為下肢檢測的便利性方法，因此本研究擬採用立定垂直跳動作為研究工具，並利用高速攝影機(Vicon MX13+, Germantown, Oxford, UK, 250Hz)，測力板(Kistler 9281, Kistler Instrumente AG, Winterthur, Switzerland, 1000Hz)，肌肉電訊號(Noraxon U.S.A. Inc., Arizona, USA, 1500Hz)等儀器收集身體活動資料，經過分析後，所得參數使用二因子變異數分析來進行統計分析(α = .05)，如達差異則利用bonferroni法進行事後比較。結果發現年齡會帶來退化的結果，而太極拳族群與健康休閒族群相比有較佳的跳躍能力；下蹲期時太極拳族群有較佳的下肢關節活動度；起跳期時的運動學與動力學參數普遍為太極拳族群優於健康休閒組族群；著地時則為中老年人有較好的表現，太極拳族群則在下肢勁度有較好的表現。依照本研究結果，鼓勵中老年人與老年人可以規畫長期規律的參與太極拳運動，以訓練下肢各肌群力量，期望減緩下肢肌肉因老化所造成的退化，除將影響日常生活功能程度減低外，並希望可降低中老年人與老年人跌倒發生風險。

This study sought to compare the biomechanical parameters of the lower extremities during a standing counter movement jump between elderly people who are engaged in a long-term regular practice of tai chi chuan and the general population of healthy elderly people. Each group included 24 participants, and 48 middle-aged elderly and elderly people participated in this study. Ten Vicon Motion System infrared cameras (Vicon MX13+, Germantown, Oxford, UK, 250Hz), two Kistler force plates (Kistler 9281, Kistler Instrumente AG, Winterthur, Switzerland, 1000Hz), Noraxon EMG (Noraxon U.S.A. Inc., Arizona, USA, 1500Hz), and Vicon Nexus software were used for the real-time measurement of the kinematic and dynamic parameters during a standing counter movement jump. Visual 3D software was used for the calculations. The data were standardized and analyzed using independent two way ANOVA, and α = .05 was set as the significance level. There was significant difference found in the jump height between the tai chi chuan group and the healthy group, and between the middle-aged elderly and the elder. Peak knee moment, peak ankle moment, peak hip power, peak knee power, and peak ankle power during the takeoff phase were significantly greater in the tai chi chuan group than in the healthy group. Tai chi chuan group also have greater lower limber stiffness, suggesting that tai chi chuan helped slow the degradation of lower limber. It is recommended that the elderly engage in long-term tai chi chuan practice.

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