国家网球队女子运动员一区一、二发球技术的运动学研究

A Kinematic Study on the First and Second Serve Techniques of the National Tennis Team’s Female Players in Zone One

目的:探究网球一区一、二发球时,抛球高度和击球位置、左膝屈曲最小时刻、击球瞬间球拍转动相关运动学参数分别与发球球速和球拍挥速的关系,找出影响发球球速和挥速的关键因素,为提高国家队网球女子选手的竞技水平提供理论参考。方法:采集5名国家网球队运动员集训时一区一、二发技术动作的三维运动学数据,对其进行相关性分析。结果:①运动学参数与球速:一区一发时,左膝屈曲最小时刻的右膝角以及击球瞬间球拍转动中Z转动角度和角速度与球速呈负相关关系。一区二发时,抛球-击球Y(抛球-击球向前距离)以及左膝屈曲最小时刻球拍Z转动角度与球速呈正相关关系。②运动学参数与挥速:击球位置X(击球位置向右)与二发挥速呈正相关。左膝屈曲最小时刻,挥速与一发球拍转动角度X呈负相关,而与二发球拍转动角度呈正相关。挥速与一发球拍转动角度Y呈正相关。挥速与一、二发球拍转动角度Z均呈正相关。身体关节方面,挥速与一侧肩髋水平面夹角呈负相关关系。此外,挥速均与一发、二发右肩角呈负相关。击球瞬间球拍转动中,挥速与一发X轴角速度呈负相关。此外,挥速与二发Y轴角速度呈正相关。结论:①运动学参数与球速:一区一发时,下蹲最低时刻运动员右膝角越小,以及击球瞬间球拍内旋角度越多、内旋角速度越快,球速越高;一区二发时,在合理范围内,抛球越往前,下蹲最低时刻球拍外旋越多,球速越快。②运动学参数与挥速:一区一发时,左膝屈曲最小时刻球拍拍面越下压、越右旋、越外旋、肩髋水平面夹角越大和右肩角越小,以及击球瞬间球拍下压的角速度越快,挥速则越高;一区二发时,抛球越往身体右上方抛,左膝屈曲最小时刻球拍拍面越上仰、越右旋以及右肩角越小,击球瞬间球拍右旋的角速度越快,挥速越快。

OBJECTIVE:This study aims to investigate the relationships between kinematic parameters such as toss height,hitting position,the timing of minimal left knee flexion,and racquet rotation at the point of impact during the first and second serves in tennis.The focus is on how these parameters relate to serving ball speed and racquet swing speed.The objective is to identify the key factors influencing both serving ball speed and swing speed,ultimately providing theoretical insights to enhance the competitive performance of female players in the national tennis team.METHOD:We collected three-dimensional kinematic data from five athletes in the national tennis team during training sessions,specifically examining their techniques for the first and second serves.We then conducted a correlation analysis of the data.RESULTS:(1)Kinematic parameters and ball speed:During the first serve,a smaller right knee angle at the moment of minimal left knee flexion,along with greater racquet rotation in the Z-axis and higher angular velocity at the moment of impact,were negatively correlated with ball speed.In the case of the second serve,the forward distance between toss and impact(toss-to-impact forward distance)in the Y-axis and the Z-axis rotation angle of the racquet at the moment of minimal left knee flexion were positively correlated with ball speed.(2)Kinematic parameters and swing speed:For the second serve,a hitting position to the right in the X-axis showed a positive correlation with swing speed.At the moment of minimal left knee flexion,swing speed exhibited a negative correlation with X-axis racquet rotation angle for the first serve and a positive correlation with X-axis racquet rotation angle for the second serve.Swing speed displayed a positive correlation with Y-axis racquet rotation angular velocity for both first and second serves.In terms of joint angles,swing speed was negatively correlated with the angle between the shoulder and hip horizontal planes for both first and second serves.Furthermore,swing speed showed a negative correlation with the right shoulder angle for both first and second serves.In the racquet’s rotational motion at the moment of impact,swing speed was negatively correlated with X-axis angular velocity for the first serve and positively correlated with Y-axis angular velocity for the second serve.CONCLUSIONS:(1)Kinematic parameters and ball speed:In the context of the first serve,achieving a smaller right knee angle at the moment of minimal squat,coupled with increased internal racquet rotation angles and faster internal racquet rotation angular velocities,resulted in higher ball speeds.On the other hand,for the second serve,tossing the ball further forward within a reasonable range,along with more external racquet rotation during the moment of minimal squat,led to faster ball speeds.(2)Kinematic parameters and swing speed:For the first serve,a more downward,rightward,and external racquet face angle,as well as a greater angle between the shoulder and hip horizontal planes and a smaller right shoulder angle at the moment of minimal left knee flexion,along with faster downward angular velocity of the racquet at the moment of impact,contributed to higher swing speeds.In the case of the second serve,tossing the ball more towards the upper-right side of the body,achieving a more upward and rightward racquet face angle at the moment of minimal left knee flexion,and maintaining a smaller right shoulder angle,combined with faster rightward angular velocity of the racquet at the moment of impact,resulted in higher swing speeds.