以平跳及高跳出發探討各入水參數對截面積及滑行期的影響

Abstract

本研究主要在探討，各入水參數及身體姿勢對於截面積及水底滑行期的影響，希望藉由結果改善選手的出發動作、減低水阻，以增進滑行期表現。十三位男性受試者皆為甲組水準的選手，年齡平均為18.31±2.84 歲，泳訓時間平均7.77±3.98年。以Peak攝影機（60Hz）、JVC（60Hz）行2-D攝影法，來蒐集騰空期及滑行期的資料。結果分析後得到： （1） 在滑行期方面，攻擊角與截面積皆與滑行表現呈負相關，若欲減小 水阻以維持前進動量則必需減小攻擊角與截面積。 （2） 另外，影響入水截面積最重要的因素是攻擊角（相關值達0.92，兩者呈高度正相關）。 （3） 動作技術上，身體傾角大於入水角度時較能減小入水截面積；故為盡量減低入水截面積，有必要進一步修正身體入水角度。

關鍵詞：游泳出發、入水截面積、攻擊角、滑行期

The purpose of this study was to investigate the influence of entry kinematic variable and body position on hole size and glide phase. In addition, we hope to find a proper posture of entry to reduce the water resistance, so that swimmers may perform better during the glide. Thirteen skilled male swimmers were served as the subjects for the study. Their mean age, training years were 18.31±2.84 years, and 7.77±3.98 years respectively. One peak camera (60Hz) and one JVC camera (60Hz) were used to collect the data on flight and glide phase. The result was showed as below: （1） There is high negative relation between angle of attack and glide performance, same situation exists between hole size and glide performance as well. So that minimizing the drag force caused by the two events will maintain the momentum of the dive. （2） There is extremely high positive relation between attack of angle and hole size (r= .92, P< .01), which means the higher the angle of attack, the larger the hole size would be. As for entry technique, no matter what kind of start method used, as long as the angle of body larger than the angle of COM, certainly it would result in smaller hole. （3） Because the hole size mainly affected by the posture of body. In order to minimize the range of hole size, the angle of legs need to be modified.

Key words: Swimming start, Hole size, Angle of attack, Glide phase