知覺桌球正拍攻擊落點方向之關鍵時間、空間訊息

The critical temporal and spatial information about the landing direction of table tennis forehand attack

目的：本研究以時間／空間遮蔽典範，探討精熟之桌球運動員在預期判斷桌球技術之正手位正拍攻擊動作來球落點方向之關鍵時間、空間訊息。方法：以120Hz之高速攝影機拍攝精熟之桌球男子選手正拍攻擊動作後，再以60Hz將影片剪輯成四種時間遮蔽：擊球前450ms（T1）、擊球前225ms（T2）、擊球點（T3）、與擊球後225ms（T4）；與五種空間遮蔽：遮蔽球體（OB）、球拍（OP）、手臂（OA）、軀幹（OT）和頭部（OH）。以34位精熟之桌球選手（21.79±2.21歲）觀察50個空間遮蔽和40個時間遮蔽的影片動作來預期判斷來球之落點方向，依變項為依據實驗參與者的回答記錄，而換算成預期判斷空間／時間遮蔽之來球落點方向的正確百分比。結果：百分比顯著性考驗顯示，來球落點為右邊時，T3、T4與5種空間遮蔽時實驗參與者能準確判斷，當球落點為左邊時，在T2、T3和T4與遮蔽OB與OA時，實驗參與者能準確判斷。二因子相依樣本變異數分析顯示，空間遮蔽與落點方向以及時間遮蔽與落點方向之交互作用皆達顯著。空間遮蔽方面，遮蔽OP、OT、OH時落點方向在右邊之判斷準確性高於落點方向為左邊者。在時間遮蔽方面，呈現愈長之時間訊息，判斷之準確性愈高，但T2與T3在不同落點之準確性呈現相反的結果。結論：精熟的桌球選手在預期判斷桌球正手位正拍攻擊之關鍵時間、空間訊息時，擊球落點至左邊時，精熟的桌球運動員能在較早的遮蔽時間點上做出有效的預期判斷；並且會因來球落點方向的不同，而在時間遮蔽點和遮蔽空間肢段上有不同的預期判斷結果。Purpose: The present study used the temporal and spatial occlusion paradigms to investigate the anticipation of landing direction of table tennis forehand strike in elite table tennis players. Methods: Thirty-four elite table tennis players (21.79 ± 2.21 years) served as participants. An 120Hz high-speed camera was used and the films were edited into two sets of 60 Hz films. The first set (40 trials) included four types of temporal occlusions, 450 ms before stroke (T1), 225 ms before stroke (T2), till moment of stroke (T3), and 225 ms after the stroke (T4). The other set (50 trials) included five types of spatial occlusions, spatial occlusion of the ball (OB), the paddle (OP), the arms (OA), the trunk (OT), and the head (OH). Results: The percentage significance test showed that when landed at the right side of the table, participants were able to accurately anticipate the landing direction at T3, T4 and all five spatial occlusion conditions. When landed at the left side, they were able to accurately anticipate the landing direction at T2, T3, T4, OB, and OA, and OT. Two-way repeated measures ANOVA indicated significant interaction effects of the Landing direction × Temporal occlusion and the Landing direction × Spatial occlusion. The more accurate anticipation was accompanied with the longer temporal information; however, reverse accuracy of landing direction was shown at T2 and T3. In terms of spatial occlusion, the anticipatory accuracy of right side was higher than that of the left side at OP, OT, and OH. Conclusion: When landed at the left side of the table, the elite table tennis players could anticipate the ball direction earlier. The critical temporal and spatial information about forehand attack varies in different landing directions in elite table tennis players.