对世界优秀男子网球运动员不同站位发球技术的运动学对比分析

Kinematics Analysis on Different Positions'Serve Skills inWorld Elite Male Tennis Players

目的:网球比赛发球站位基本包括上步式站位(foot-up,FU站位)和分腿式站位(foot-back,FB站位)两大类,而用哪一类站位动作发球效果更好,在国内外网球界有歧说。通过在比赛现场高速摄像,经3D解析结合VR技术对世界优秀男子网球运动员不同站位发球技术的运动学对比分析。方法:在2018年成都网球公开赛比赛现场应用高速录像拍摄决赛,选取冠军托米奇(FU站位)、亚军弗格尼尼(FB站位)各7次发球动作技术三维解析,获得运动学参数,导入VR技术系统进行对比分析。结果:托米奇采用FU站位发球开始右脚上步,人体获得动能通过下肢制动转化为下肢肌肉弹性势能储存起来,紧接着起跳再释放,获得较大的地面垂直反作用力,增加身体重心垂直位移的高度。同时,抛球离手速度较快。托米奇在向后引拍阶段用时较短,右髋角速度更快,有利于增加下肢向击球方向的转动速度以及起跳速度。不仅获得了更合理的击球高度,而且球拍触球时刻各关节速度均快于弗格尼尼,使鞭打击球动作更连贯。同时,球最高点与击球点的垂直距离更小,使击球高度的稳定性更高。在挥拍触球时刻,弗格尼尼击球点多数更靠前,球拍击球点在甜区上缘。托米奇击球点在甜区,比弗格尼尼位置更好。托米奇的平均发球时速为179 km/h,弗格尼尼的平均发球时速为174 km/h。托米奇全场比赛发内角球49%、外角球36%,合计85%,而弗格尼尼发内、外角球合计为79%,托米奇的发球速度和落点均比弗格尼尼更好,发球攻击性比较强。此外,托米奇在全场比赛的一发成功率和一发得分率均比弗格尼尼高。结论:托米奇采用FU站位发球比弗格尼尼采用FB站位发球不管是攻击性还是稳定性均技高一筹。

Objective:There are two serving positions in tennis matches,i.e.,FU/foot-up and FB/foot-back,but which one is better has no certain conclusion.This study analyzed the kinematics parameters of the world's elite male tennis players in different positions combined with the VR technology,and hope to get some meaningful conclusions.Methods:The 3D high-speed video was used to record the finals at the Chengdu Open Tennis Tournament,7 technical actions of the champion Tomic(FU position)and runner-up Fognini(FB position)were obtained to make comparative analysis.Results:Tomic used the FU position to serve and started to move on the right foot.His body gains kinetic energy and converts it into elastic energy of the lower limb muscles through the braking of the lower limbs.Then he took off and released energy to obtain a larger vertical reaction force on the ground and increase the vertical displacement of the center of gravity of the body,the tossing speed was faster(5.02 m/s).Tomic took a shorter time in the backward introduction phase,and the speed of right hip angle was faster,which was beneficial to increase the rotation speed and take-off speed of the lower limbs in the direction of impact.This position not only obtained a more reasonable hitting height,but also the joints were faster than Fognini when the racket touches the ball,making the whip hitting the ball more consistent.At the same time,the vertical distance between the highest point of the ball and the hitting point was shorter,so that the stability of the hitting height was higher.At the moment the racket touches the ball,Fognini's hitting point was mostly forward,and the racket hitting point was on the upper edge of the sweet spot.Tomic's batting point was in the sweet zone,better than Fergnini's position.Tomic's average serve speed was 169 km/h,which was 162 km/h of Fognini's.Tomic served 49%of the inside corners and 36%of the outside corners of the game,85%of the total,while Fognini made 79%of the inside and outside corners.The results showed that Tomic's serving speed and landing point were both better than Fergnini,that is,Tomic's serve was more aggressive.As a result,the first serve success rate and first serve scoring rate of Tomic were higher than Fognini.Conclusion:By using 3D kinematics parameters combined with VR technology,it is showed that Tomic(FU position)is superior in offensive and stability than Fergnini(FB position).