排球扣球空中手臂動作揮擺時機與扣球表現分析研究

Abstract

排球扣球技術中的揮臂擊球是扣球各環節中的關鍵，可彌補彈跳或身高不足、舉球不理想等不利因素，而且對球的力量、速度、技術有著直接影響。而空中擊球是人體失去支點，利用身體肢段在空中維持平衡完成揮臂擊球的技術動作，必須在0.5~0.8秒完成手臂後拉、轉折、加速揮臂進而完成手臂、身體軀幹與地面呈垂直面的擊球動作，所以是技術環節的困難點，因此本研究目的為找出扣球空中手臂動作揮擺最佳時機與身體肢段之運用。 方法以高速攝影機以（500frame/sec）矢狀面拍攝排球扣球空中動作，利用kwon 3D影像分析軟體分析女子特優級與女子乙組選手空中手臂揮擺動作的最佳時機及其身體肢段相對動作。 從研究結果可發現，女子特優級選手能夠充分發揮身體各肢段維持平衡及發力，雖手臂後拉時間需較多時間，因提早起始後拉動作則可在較佳擊球點擊球，並增加更多的有效動作空間促使發力，使手臂與身體肢段呈180°的擊球動作，進而達到得分之目標。因此可提出以下結論：要完成完整的扣球手臂揮擺動作時間要愈早愈好，揮擺方向應由體側向前上方急速擺起，使肘關節轉折，整個手臂像鞭子一樣揮打，做出較多有效動作空間促使發力，在達到最佳擊球點前需完成手臂與身體呈180°的擊球動作，在上升到最佳擊球點是最好的。訓練上也可加強兩邊肩部肌群及非慣用手肌群訓練，不僅維持身體平衡更是積極發力的一種方式。Arm swing is one of the main factors among the spiking techniques, not only decrease the weakness of jumping ability, body height and mis-setting, it can also increase the power and speed of the ball, directly. Hitting ball, without ground reaction force, was performed by the balance of body segments in the air, including back-swing, turn-swing, and forward-swing should be within the duration of 0.5~ 0.8 second off the ground. Therefore, the purpose of this study was to investigate the suitable timing and coordination of body segments applied on spiking in the air. Cinematography (500 frame/sec, sagittle plane) was used in this study, and software Kwon 3D was used to anal-yze the timing and coordination of arm swing motion in the air among top level and second level female volleyball athletes. The results of this study indicated as following: the top level athlete efficiently performed the coordination of the balance of body segments. Although with longerback-swing duration, back-swing early could lead to better hit- ting point, and increase more range of motion of spiking. The conclusion was described as following: 1.the more early back-swing, the more completely arm sw- ing.2.the swing direction should be from lateral and up to lead to elbow turn-swing, like wipe motion, and execute more range of motion to spiking volleyball, and arm-trunk-leg performed as “line”shape at the hitting ball.