籃球不同距離跳投動作之生物力學分析

Abstract

本研究目的在探討四種不同距離 ( 2.25m, 4.25m, 6.25m, 8.25m ) 籃球跳投動作運動學和動力學參數上的差異。研究方法是使用二部Redlake高速攝影機（125Hz）及一塊Kistler 9287型測力板（1250Hz）收集大學體育系學生與乙組籃球隊選手在四種距離投籃的運動學與動力學參數資料；以重複量數單因子變異數分析考驗四種距離間力學參數上的差異，並以皮爾遜積差相關檢定相關的顯著性。結果發現：（一）出手速度、上肢關節出手瞬間角速度與最大角速度以及出手瞬間重心速度隨投籃距離增加而增加；（二）出手角度、出手瞬間軀幹傾斜角度及出手點至籃框的水平距離隨投籃距離增加而減小；（三）出手時機隨著投籃距離增加而提早；（四）離地前水平合衝量、水平正向衝量以及最大水平地面反作用力隨投籃距離增加而增加，水平反向衝量則是逐漸減少。由此可知，在不同距離投籃者的投籃特徵皆不相同，且影響命中率的因素也不盡相同。短距離投籃時，投籃者垂直起跳，以高拋射角將球投出；中距離投籃（罰球線），投籃者著重以較小的力量跳躍，維持身體穩定的方式進行投籃；遠距離投籃（三分線），投籃者改以向前跳躍的方式，並利用重心速度來增加出手速度；而超長距離投籃時，投籃者除了有遠距離投籃的特徵外，在出手瞬間還有身體前傾的現象。因此未來教練指導學生投籃時，應瞭解不同距離投籃的動作特徵，並在教學上有所調整，較能達到事半功倍的效果。

The purpose of this study was to compare the kinematics and the kinetic variables of basketball jump shot in four different distances (2.25m, 4.25m, 6.25m, 8.25m). Two Redlake high-speed digital cameras (125Hz) and one Kistler force platform were to record the kinematic and the kinetic data of 10 students of physical education department and 5 basketball players of secondary university team when they were shooting in four designated distances. The differences of parameter in each distance are analyzed with one-way ANOVA for repeated measures and the relation between parameters is examined with Pearson product-moment correlation. Result: (1) The release velocity, the angular velocity at release, the maximum angular velocity of the joints of upper extremity and the CM velocity at release increased while along with the distance increased. (2) The release angle, the angle of trunk inclination and the horizontal distance between release spot to the basket were decreased while the distance increased. (3) The release timing of the jump shot advanced as the distance increased. (4) The total AP impulse, the propulsive impulse and the maximum AP ground reaction force before take-off increased along with the distance increased, while the braking impulse decreased as the distance increased. In conclusion, the characters of the movement of jump shot and the factors which affect the shooting average are not identical in different distances. When shooting in short range, the subjects jumped more straight up and shot with relatively larger release angle. When shooting in middle range (free-throw line), they jumped with less force to shoot with steady base. When shooting in long range (three-point line), they changed the jump featurefrom straight up to forward, and increase release velocity by increasing CM velocity. When shooting in super long range, they revealed phenomenon of leaning forward, in addition to their performing of the character of the movement in long range. As the results, the coaches should emphasis on different strategies in different distances when teaching students shooting to yield the best result.