乒乓球正手快攻和弧圈球技术中球拍的运动学特征

对10名乒乓球运动员正手快攻、弧圈球技术(每种技术分中等力量和最大力量两种发力方式)进行测试与分析后发现,重打和重拉的引拍结束时刻的球拍速度分别大于轻打和轻拉.在击球时刻,轻打的速度小于重打,轻拉的速度小于重拉,重打的速度小于重拉;正手弧圈球技术的总时间长于正手快攻技术;拉的幅度大于打的幅度.     

The effect of ball impact location on racket and forearm joint angle changes for one-handed tennis backhand groundstrokes

Recreational tennis players tend to have higher incidence of tennis elbow, and this has been hypothesised to be related to one-handed backhand technique and off-centre ball impacts on the racket face. This study aimed to investigate for a range of participants the effect of off-longitudinal axis and off-lateral axis ball–racket impact locations on racket and forearm joint angle changes immediately following impact in one-handed tennis backhand groundstrokes. Three-dimensional racket and wrist angular kinematic data were recorded for 14 university tennis players each performing 30 “flat” one-handed backhand groundstrokes. Off-longitudinal axis ball–racket impact locations explained over 70% of the variation in racket rotation about the longitudinal axis and wrist flexion/extension angles during the 30 ms immediately following impact. Off-lateral axis ball–racket impact locations had a less clear cut influence on racket and forearm rotations. Specifically off-longitudinal impacts below the longitudinal axis forced the wrist into flexion for all participants with there being between 11° and 32° of forced wrist flexion for an off-longitudinal axis impact that was 1 ball diameter away from the midline. This study has confirmed that off-longitudinal impacts below the longitudinal axis contribute to forced wrist flexion and eccentric stretch of the wrist extensors and there can be large differences in the amount of forced wrist flexion from individual to individual and between strokes with different impact locations.     

直拍横打技术对广东高校乒乓球教学的启示

通过对第49届世界乒乓球锦标赛团体赛马琳对柳承敏的录像分析,发现双方均是直拍快攻型选手,而马琳反手是推挡加横打型,柳承敏反手是推挡加攻球型,马琳的直拍横打优于柳承敏的反手推挡,直拍横打解决了直拍运动员反手攻击力不强的问题,直拍近台快攻打法有强大的生命力。结合广东部分高校体育专业乒乓球班学生与普通系乒乓球班学生的现状进行分析,访谈了广东高校一些乒乓球教师,结果表明,广东高校乒乓球直拍横打的发展比较滞后,应该在乒乓球教学中采取措施开展直拍横打,方能使乒乓球的群众性运动进一步发展。     

Development of inertial and novel marker-based techniques and analysis for upper arm rotational velocity measurements in tennis

This paper examines three methods to measure the upper arm rotation, the main contributor to produce a fast first serve in tennis. Accepted videography techniques were compared with a novel inertial gyroscope system and marker-based technique. A network of two inertial sensors on the upper arm and the chest was used to measure upper arm rotation angle and remove body artifacts. A marker-based virtual gyroscope (MBVG) was derived from Vicon marker positions in the standard Plug-in-Gait model using a vector-based method of marker trajectories and a series of geometric transformations. The results indicate that there is a close temporal feature match for all three methods when applied to the tennis serve. This paper shows that gyroscopes as well as the MBVG can be advantageous for tennis serve assessment.     

从技战术角度分析王皓在北京奥运会乒乓球男单决赛中失利的原因

运用三段技术统计法对王皓在北京奥运会乒乓球男单决赛中的发球抢攻段、接发球抢攻段和相持段的技术进行统计并分析,以期找出其失利的原因,并由此探讨王皓在技战术上存在的问题.结果表明:马琳对王皓的发球控制严密,使王皓发球后难以上手,造成发抢段得分率不高;接发球抢攻段技术较顺,积极主动,表现出色,但接发球手段略显单一.相持球中正手对拉和反手横拉失误过多,打关键球能力较差.