兩種單槓後擺脫手騰越轉體180°接槓動作之技術分析

本研究主要目的在於探討4位選手實施兩種單槓後擺脫手騰越轉體180°接槓動作的技術特徵。採用二部高速攝影機(JVC-9800；60Hz)，以APAS運動影像系統進行分析，使用MRI法建立之男子競技體操選手的人體肢段參數，設定19個人體肢段點，14個剛體肢段的人體模型，將實施動作過程分為7個位置點。本研究針對4位選手完成動作過程中，各位置的肩、髖關節角度及角速度、身體重心速度、身體重心高度、時間變化及騰空階段之技術等進行分析，所得結果敘述如下：（一）A、B選手較能運用肩、髖關節角度伸展及收縮的變化，藉以獲得較佳的動力來源。（二）四位選手的肩、髖關節角速度皆出現二個高峰（第四位置，沉浪、第六位置，脫手）。（三）動作過程中A、B選手的身體重心水平速度皆低於C、D選手，但是身體重心垂直速度及卻明顯高於C、D選手，在動作過程中有較佳的垂直速度有利於完成Yamawaki動作。（四）A、B選手在沉浪階段的時間較長，藉以儲備身體軀幹及下肢後擺之動能，並且較早完成後擺及脫手的動作技術，使其身體重心得以快速往垂直方向移動增加騰空時間。（五）A、B選手較早完成壓槓脫手，在脫手時其下肢與肩、髖關節呈現水平狀態，而身體出現縮肩、含胸、直髖的體勢，於脫手後肩部快速上揚而下肢朝順時針方向移動，在空中轉體階段亦保持直體之體勢，在預備接槓時已完成轉體動作身體呈現垂直的狀態。（六）C、D選手完成壓槓脫手的時間點過晚，導致脫手時身體出現開肩、挺胸的體勢，由於下肢後擺幅度過高，脫手後減緩肩部上揚幅度及下肢往下移動的速度，影響騰空階段的轉體技術實施而出現髖關節縮收的狀態，在預備接槓時亦尚未完成轉體動作身體體勢側斜。

關鍵字

競技體操；單槓；後擺脫手騰越轉體180°接槓；技術分析

並列摘要

The purpose of this study was to analyze 4 gymnastics performing two kinds of back-up rise and vault with 1/2 to hand on the horizontal bar. The data was collected by a JVC-9800 digital video camera (60 Hz), and a 14-segment human body model was used and 19 markers were digitized by the Ariel performance analysis system. Moreover, the individual body segment parameters used in this study were established by the MRI method. This study divided motion of back-up rise and vault with 1/2 to hand into 7 phases by a clear definition and compared kinematic parameters of 4 gymnastics which included the joint angle, the angular velocity, the velocity and the height of CM, the period of each phase and the technique in the air. The results were as follows. First, subjects A & B used more shoulder and hip angular extension and flexion to obtain better motive power. Second, shoulder and hip angular velocity of all subject showed two peaks (at position 4(superscript th) & 6(superscript th)). Third, the horizontal velocity of CM of subjects A & B were lower than those of subjects C & D, but the vertical velocity of CM was higher than that of subjects C & D, so the higher vertical velocity is better for performing Yamawaki. Fourth, subjects A & B have longer duration in downswing and performed take-off technique earlier; therefore, CM would be able to move more rapidly to the vertical direction. Fifth, subjects A & B took a shorter time to complete the off-bar motion, while their hands leave the bar, their lower extremities, shoulder and hip joints were horizontal; after their hands leave the bar, the shoulders rose rapidly, and the lower extremities moved clockwise, and then the whole body was kept straight in the air. When subjects were ready to catch the bar, they both finished the twist motion and their body turned perpendicular. Sixth, subjects C & D took a longer time to complete the off-bar motion, which resulted in hip joints contraction while the bodies were twisted in the air, and when subjects C & D were going to catch the bar, they did not finish the twist motion and their body were in an oblique position.