最佳負重與未負重立定跳遠之下肢關節運動生物力學分析

Biomechanical analysis of lower extremity between optimal load and no load standing long jump

過去針對立定跳遠之硏究，已證實適當負重可增進運動表現；然而過去硏究負重立定跳遠對於關節力矩以及功率之硏究則非常缺乏，因此本硏究將依據動力學逆過程所得到之資料，來討論下肢關節淨肌肉作用之結果。硏究目的：一、探討本硏究之最佳負重，能增加多少立定跳遠運動表現；二、探討最佳負重與未負重，那些運動生物力學參數會影響動作表現。硏究方法：受試者是十四名體育學系之男生(身高174.64±6.21cm，體重73.07±11.32kg)，每個人接受無負重立定跳遠，以及四種負重試跳(2kg、4kg、6kg、8kg)之立定跳遠測驗，選取負重表現最佳的一次，與無負重表現進行比較。本硏究利用一部Redlake高速攝影機(125Hz)同步一部Kistler測力板（1250Hz)收集受試者之運動生物力學資料，結合各受試者之人體肢段參數資料、動力學資料以及運動學資料，運用動力學逆過程之方式，計算得到下肢各關節之力矩及功率。結果：立定跳遠成績、起跟湩心水平速度、水平衝量、動作時間、髖關節向心期、髖關節向心作功量，最佳負重組皆大於未負重組；起跳重心垂直速度則是未負重組較大。結論：一、透過本硏究之最佳負重進行立定跳遠，能增加立定跳遠5.57%之運動表現。二、起跳瞬間重心水平速度、推進期水平衝量、下肢產生之髖關節向心期作功量之增加，以及髖關節伸展角速度提前增大，是造成最佳負重組立定跳遠成績大於未負重組之主要因素。

Background: Many studies had proved that extra weights was held in the hands of the athletes during the long jump competition， and some researchers found that extra weights would increase the jump distance， but no data on lower extremity joint moment and power were presented. The purpose of this study was to investigate the biomechanical difference between unloaded and optimal load groups， and to find out the main factors influencing the performance of standing long jump. Methods: Fourteen male physical education students (height 174.64 ± 6.21 cm， weight 73.07 ± 11.32 kg) participated the study， and performed 4 loads ( load 2，4，6，8 kg) standing long jumps. A Redlake high speed camera(125Hz) was synchronized with a Kistler force platform( 1250Hz) to collect the data. Dempester’s study (1955) was used to calculate the human body parameter， and we used inverse dynamic methods to calculate the moment and power of lower extremity. One way ANOVA was used to analyse the data. The SPSS for Windows was used to test the variables (Version 12.0， Chicago， IL) with alpha level of 0.05. Results: The jumping distance ( 284.4 m>269.4 m) ， takeoff CM(center of mass) horizontal velocity (3.11 m/s>2.84 m/s)， horizontal impulse( 294.9 N.s>257.8 N.s) ， movement time ( 662 ms > 543 ms) ， and hip concentric work ( 302.4 J>249.6 J) ， were enhanced in the optimal load. The takeoff CM vertical velocity was decreased in the optimal load. Conclusions: The study indicated that the optimal load had greater performance than no load group， and it helped to enhance 5.57% standing long jump distance. The increase of takeoff CM horizontal velocity， horizontal impulse， and hip joint concentric work， were the main factors enhanced the jumping distance.