網球第二發球之運動學分析(以上旋式及側旋式為例)
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2005
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Abstract
在網球比賽中，發球為最重要的技術之一，也是主要得分手段。而第二發球(second serve)在比賽中亦佔舉足輕重的地位。正確的第二發球方式不僅能避免無謂的失分，更能避免處於劣勢。本研究以一部Redlake高速攝影機(250Hz)，針對十名國內大專網球甲組球員上旋式及側旋式的第二發球作二度空間的運動學分析，主要在探討不同第二發球的運動學變數，並了解發球方式對進球率及球速的影響，找出較佳的第二發球方式，以供教練或教師教學參考依據。資料分析是擷取每位受試者的不同第二發球發進指定區域五球中球速最快的動作做比較。影片資料經由kwon3D 3.0版軟體分析，統計處理以SPSS統計軟體計算分析，以 a=.05顯著水準的相依樣本t考驗得到下面的結果：
一、擊球高度及準確率，兩者皆未達顯著差異。
二、擊球後球速，側旋式發球球速(32.93m/s)較上旋式發球(30.92m/s)為快(P< .05)。
三、上肢關節角速度、線性速度方面：
(一)側旋式發球肩關節角速度比上旋發球快(P< .05)，而肘及腕關節也有較高的平均值。
(二)側旋式及上旋式發球肩關節線性速度未達顯著差異。
(三)側旋式發球肘關節及腕關節線性速度分別為4.09m/s及7.0m/s，與上旋發球3.7m/s及5.72m/s達顯著差異。
本研究結論如下：在運動學方面，側旋發球有較快的角速度及線性速度，以致於會有較快的發球速度。而且側旋發球也有高平均的準確率。因此，選手可依比賽需求多搭配使用側旋球。。
In a tennis game, serving was one of the most important skills as well as the major strategy to gain points. The second serve plays an important role in a game, too. A correct second serve can avoid not only the loss of points but also an inferior situation. In this study, a Redlake high-speed (250Hz) camera was used to record the top spins and side spins of second serves made by ten first-rate college tennis players in Taiwan, and a two-dimensional kinematical analysis was made on these serves. The purpose was to examine different kinematic variables that may affect the second serve, to understand the influence the style of the serve may have on the precision and the speed of the ball, and to find out a better way of doing a second serve, which can be a reference to coaches and teachers in their instruction.In the experiment, the players were asked to do 5 second serves into an assigned area, the fastest which was chosen to be compared in terms of the player’s postures. The data were calculated and analyzed through the statistical software kwon3D 3.0 and SPSS Paired-Samples t-Test, a=.05. The results were as following: 1. Neither the impact height nor the precision of the serves was significantly different. 2. In terms of the speed after the ball was hit, side spin second serves (32.93m/s) were faster than top ones (30.92m/s) (P< .05). 3.As for the angular velocity and resultant velocity of the joint of the forearm: (1) In terms of the angular velocity of the joint of the shoulder, side spin serves were faster than top spin ones. There were also higher averages (of angular velocity) in the joints of the elbow and the wrist in side spin serves. (2)There was no significant difference in the resultant velocity of the shoulder joint between side spin and top spin serves. (3)The resultant velocities of the elbow joints andthe wrist joint were 4.09m/s and 7.0m/s respectively in side spin serves, which were significantly different from those in top spin serves, 3.7m/s and 5.72m/s.The conclusions of this study were as following: In kinematics, side spin serves has faster angular velocity and resultant velocity, so that it can produce a higher speed in serving. Besides, side spin serves has a higher average of precision. Therefore, Players can adopt more side spins in the tennis games.
In a tennis game, serving was one of the most important skills as well as the major strategy to gain points. The second serve plays an important role in a game, too. A correct second serve can avoid not only the loss of points but also an inferior situation. In this study, a Redlake high-speed (250Hz) camera was used to record the top spins and side spins of second serves made by ten first-rate college tennis players in Taiwan, and a two-dimensional kinematical analysis was made on these serves. The purpose was to examine different kinematic variables that may affect the second serve, to understand the influence the style of the serve may have on the precision and the speed of the ball, and to find out a better way of doing a second serve, which can be a reference to coaches and teachers in their instruction.In the experiment, the players were asked to do 5 second serves into an assigned area, the fastest which was chosen to be compared in terms of the player’s postures. The data were calculated and analyzed through the statistical software kwon3D 3.0 and SPSS Paired-Samples t-Test, a=.05. The results were as following: 1. Neither the impact height nor the precision of the serves was significantly different. 2. In terms of the speed after the ball was hit, side spin second serves (32.93m/s) were faster than top ones (30.92m/s) (P< .05). 3.As for the angular velocity and resultant velocity of the joint of the forearm: (1) In terms of the angular velocity of the joint of the shoulder, side spin serves were faster than top spin ones. There were also higher averages (of angular velocity) in the joints of the elbow and the wrist in side spin serves. (2)There was no significant difference in the resultant velocity of the shoulder joint between side spin and top spin serves. (3)The resultant velocities of the elbow joints andthe wrist joint were 4.09m/s and 7.0m/s respectively in side spin serves, which were significantly different from those in top spin serves, 3.7m/s and 5.72m/s.The conclusions of this study were as following: In kinematics, side spin serves has faster angular velocity and resultant velocity, so that it can produce a higher speed in serving. Besides, side spin serves has a higher average of precision. Therefore, Players can adopt more side spins in the tennis games.
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網球, 第二發球, 上旋式, 側旋式, 運動學, tennis, second serve, top spin, side spin, Kinematics