國小學童不同高度著地之生物力學分析

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1997-12-01

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國立臺灣師範大學體育學系

Abstract

本研究的目的是在比較國小學童不同高度(20、40、60 公分)赤腳著地時的運動 學和動力學特徵。實驗以臺北市社子國小八名六年級男性學童為受試者,平均身高為 149.9 ± 5.6 公分,平均體重為 40.8 ± 4.5 公斤,平均年齡為 12.1 ± 0.3 歲。 運動學和動 力學的資料是使用 Peak Performance 高速攝影機( 120 Hz )和 KISTLER 測力板 9287 型( 1200 Hz )同步收集資料,並以重覆量數單因子變異數分析(�` = 0.5 )處理著地時 各階段的生物力學變數,達顯著差異後再以薛費法進行事後比較。結果發現:髖、膝關節角 位移, 下肢關節之最大角速度,緩衝的時間,地面垂直反作用力的第一峰值,50 毫秒內的 被動衝量,緩衝期內的全部衝量,隨著地高度的增加而顯著增加;而著地瞬間髖、膝關節角 度,重心最低時髖、膝關節角度,踝關節最大角速度產生時間,隨著地高度增加而減少。因 此在赤腳著地時,可能因為動作不正確而使得骨骼肌肉系統因承受不了過大的力量和衝量而 發生潛在性的傷害。所以在赤腳著地時,建議國小學童時要增加下肢關節(尤其是髖、膝關 節)的角位移,以延長緩衝的時間,而減低因著地所產生的巨大撞擊力量,避免可能造成的 傷害。
The purpose of this study is to annualize the kinematic and kinetic differences of children drop landing whth barefoot from three different heights(20,40.60cm).Eight mal six grades as the subjects for this study. The mean height, mass and age were 149.9 ± 5.6cm,408 ± 4.5kg, and 12.1 ± 0.3years respectively. Kinematic and Kinetic data were acquired simultaneoysly by using a peak preformance high speed camera(120 Hz)and a kistler(model 9287)force platform(1200Hz). The selected variables were tested by one-way repeated ANOVA( �` =0.5) and Scheffe method posterior comparisons. The results indicated that there ware significant increases inf lower extremity jojints displancement(hip and knee jojnts) and the greatest angular velocities, total landing time, first peak vertical reaction force, 50ms impulse and the total landing impulse as the landing height increases. Alos, there were significant decreases in hip and knee angles at landing, hip and knee angles and boby CG(center of gravity) at the lowest point, and time to the maximun ankle angular velocity as the landing heipht increases. During the barefoot landing, the improperly landing skill may increase the possibility of injury,It is suggested that when teaching children landing form a greater height, the children should increase lower extremity joints displacement, increase landing time, which will reduce the impact force, in order to avoid the potential of injury.

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