A kinematic comparison between long-line and cross-court top spin forehand in competitive table tennis players

ABSTRACT

The aim of the present study was to compare the biomechanical characteristics of the table tennis top spin shot when played cross-court (CC) or long-line (LL) in competitive table tennis players. Seven national level players respectively completed 10 long-line and 10 cross-court top spin shots responding to a standard ball machine. A stereophotogrammetric system was used to track body segments while executing the motion. Significantly more flexed right knee and elbow angles were measured at the moment of maximum velocity of the racket (MMV) in LL. In addition, significantly greater angles between the feet and the table and between the shoulders and the table at the MMV, indicated more pronounced rotation angles of the lower upper and upper-body in LL compared to CC with respect to the table. A higher inclination of the racket at the MMV was found in LL. The elbow flexion and the racket inclination may be associated to the direction of the shot. The present findings show that kinematic differences exist between the LL and the CC topspin forehand in competitive table tennis players. Coaches should be aware of these differences to adopt the optimal teaching strategies and to reproduce proper joint angles during training.     

Glenohumeral contact force during flat and topspin tennis forehand drives

The primary role of the shoulder joint in tennis forehand drive is at the expense of the loadings undergone by this joint. Nevertheless, few studies investigated glenohumeral (GH) contact forces during forehand drives. The aim of this study was to investigate GH compressive and shearing forces during the flat and topspin forehand drives in advanced tennis players. 3D kinematics of flat and topspin forehand drives of 11 advanced tennis players were recorded. The Delft Shoulder and Elbow musculoskeletal model was implemented to assess the magnitude and orientation of GH contact forces during the forehand drives. The results showed no differences in magnitude and orientation of GH contact forces between the flat and topspin forehand drives. The estimated maximal GH contact force during the forward swing phase was 3573 ± 1383 N, which was on average 1.25 times greater than during the follow-through phase, and 5.8 times greater than during the backswing phase. Regardless the phase of the forehand drive, GH contact forces pointed towards the anterior-superior part of the glenoid therefore standing for shearing forces. Knowledge of GH contact forces during real sport tasks performed at high velocity may improve the understanding of various sport-specific adaptations and causative factors for shoulder problems.     

Kinematic differences in upper limb joints between flat and topspin forehand drives in competitive male tennis players

Abstract

The topspin tennis forehand drive has become a feature of modern game; yet, as compared to the serve, there has been little research analysing its kinematics. This is surprising given that there is considerably more variation in the execution of the topspin forehand. Our study is the first to examine the amplitude of upper limb joint rotations that produce topspin in the forehand drives of 14 male competitive tennis players using video-based motion analysis. Humerothoracic abduction (-)/adduction (+), extension (-) /flexion (+), and external (-)/internal (+) rotation, elbow extension (-) /flexion (+) and forearm supination (-)/pronation (+), wrist extension (-)/flexion (+) and ulnar (-)/radial (-) deviation were computed. Our findings revealed that the generation of topspin demanded more humeral extension and forearm pronation but less humeral internal rotation angular displacement during the forwardswing. The follow-through phase of the topspin shot was characterised by greater humeral internal rotation and forearm pronation, and reduced humeral horizontal adduction when compared to the flat shot. This study provides practitioners with a better understanding of the upper limb kinematics associated with the topspin tennis forehand drive production to help guide skill acquisition interventions and physical training.     

Mental fatigue alters the speed and the accuracy of the ball in table tennis

ABSTRACT

This study aimed at evaluating the effects of mental and muscle fatigue on table tennis performance. Mental fatigue (MF) was induced by completion of 90 minutes of the AX-CPT; muscle fatigue was induced by completion of an eccentric exercise performed with the elbow flexors (biceps fatigue, BF) or the knee extensors (quadriceps fatigue, QF). The control condition consisted of watching a movie. Stroke parameters (speed and accuracy of the ball), as well as feelings of fatigue and force production capacity of the elbow flexors (BF, MF and control conditions) and knee extensors (QF condition), were assessed pre and post fatigue protocols. Feelings of fatigue increased post fatigue protocols. Force production capacity decreased only in the BF and QF conditions. BF and MF induced a decrease in accuracy. This decrease in accuracy was associated with an increased ball speed in the BF condition, and a decreased ball speed in the MF condition. QF had a negligible effect on stroke performance. Our results suggest that both mental fatigue, and muscle fatigue, significantly impair table tennis performance and therefore coaches should take into account both the physical and mental state of table tennis players to optimize performance.     

湖北省青少年男子乒乓球运动员运动素质训练监控指标的研究

根据训练过程结构的特点,依据运动素质测试指标,运用聚类分析方法,遴选出湖北省青少年男子乒乓球运动员专项运动素质训练的代表性指标,并建立运动素质训练模式与评分标准,为湖北省青少年男子乒乓球运动员运动素质的训练监控提供理论依据和监控参数.     

我国青少年网球运动员盂肱关节旋转等速肌力研究

应用Cybex-6000等速仪器分别对136名青少年网球运动员盂肱关节内、外旋转肌力进行等速向心肌力测试与评价,分析网球运动员优势臂盂肱关节等速向心肌力特征,比较双侧盂肱关节等速向心肌力差异,探索双侧盂肱关节外旋肌力/内旋肌力比值特征,从而完善网球运动员肩部运动生物力学及有关参数,以期能为探讨网球运动员肩关节损伤的生物力学因素、机制,进而为预防网球运动员肩关节损伤以及指导网球运动员肩关节伤后进行科学的康复训练提供理论依据.     

Table tennis match analysis: a review

ABSTRACT

In table tennis, many different approaches to scientific founded match analysis have been developed since the first ones in the 1960s. The aim of this paper is to give a review on some of the most acknowledged methods of match analysis in table tennis. The first chapter presents a historical overview of match analysis from all over the world. The second part reviews different approaches to match analysis in more detail, using the performance analysis classification of theoretical and practical performance analysis. The review includes the most actual theoretical performance analysis techniques in table tennis: performance indices, simulative approaches, momentum analysis, footwork analysis, and finally an approach which uses top expert knowledge for a comprehensive technical-tactical analysis. In the section of practical performance analysis, the paper presents two “best practice” examples describing performance analysis procedures of the two most successful countries of the last Olympics: China and Japan. The paper ends with a summary on the impact of the different approaches and gives an outlook on promising new developments.     

Utilization of cues in action anticipation in table tennis players

ABSTRACT

By manipulating the congruency between body kinematics and subsequent ball trajectory, this study investigated the anticipation capabilities of regional-level, college-level, and novice table tennis players using a full video simulation occluder paradigm. Participants watched footage containing congruent, incongruent, or no ball trajectory information, to predict the landing point of the ball. They were required to choose between two potential locations to make their prediction. Percent accuracy and relevant indexes (d-prime, criterion, effect size) were calculated for each condition. Results indicated that experienced table tennis players (both regional and college players) were superior to novices in the ability to anticipate ball trajectory using kinematic information, but no difference was found between regional-level and college-level players. The findings of this study further demonstrate the superior anticipation ability of experienced table tennis players. Furthermore, the present result suggests that there may be a certain “baseline” level of motor experience in racquet sports for effective action anticipation, while the addition of further motor experience does not appear to assist direction anticipation.     

Kinematics of table tennis topspin forehands: effects of performance level and ball spin

Abstract

The purpose of this study was to investigate whether performance level and ball spin affect arm and racket kinematics of the table tennis topspin forehand. Nine advanced and eight intermediate male table tennis players hit topspin forehands against light and heavy backspins. Five high-speed video cameras were used to record their strokes at 200 fps. Contributions of joint rotations to the racket speed, the racket kinematics at ball impact, the time required for racket acceleration and the maximum slope of the racket speed-time curve (s _max) were determined. The advanced players showed a significantly larger contribution of lower trunk axial rotation to the racket speed at impact and a significantly larger value of s_max, and tended to require a less time for racket acceleration than the intermediate players. The racket speed at impact was not significantly different between the two player groups. The players adjusted the racket face angle rather than the inclination of the racket path at impact to the different ball spins. The results suggest that the ability to accelerate the racket in less time in the topspin forehand against backspin balls may be an important factor that affects the performance level.     

Hip joint kinetics in the table tennis topspin forehand: relationship to racket velocity

The purpose of this study was to determine hip joint kinetics during a table tennis topspin forehand, and to investigate the relationship between the relevant kinematic and kinetic variables and the racket horizontal and vertical velocities at ball impact. Eighteen male advanced table tennis players hit cross-court topspin forehands against backspin balls. The hip joint torque and force components around the pelvis coordinate system were determined using inverse dynamics. Furthermore, the work done on the pelvis by these components was also determined. The peak pelvis axial rotation velocity and the work done by the playing side hip pelvis axial rotation torque were positively related to the racket horizontal velocity at impact. The sum of the work done on the pelvis by the backward tilt torques and the upward joint forces was positively related to the racket vertical velocity at impact. The results suggest that the playing side hip pelvis axial rotation torque exertion is important for acquiring a high racket horizontal velocity at impact. The pelvis backward tilt torques and upward joint forces at both hip joints collectively contribute to the generation of the racket vertical velocity, and the mechanism for acquiring the vertical velocity may vary among players.     

世界优秀男子网球单打选手相持阶段的技术运用分析

对2005～2007年三届上海网球大师杯14名球员的12场单打比赛中相持阶段技术运用情况进行了统计分析,研究结果表明:(1)相持阶段得失分比例较高,占整个竞技过程的1/3,是整个竞技过程的重要组成部分.(2)正、反手抽球具有强烈上旋的底线型选手,具有较好的相持能力.(3)在相持阶段对抗中,正、反手抽球、正手侧身抽球技术的得分效率,得分比例较低,使用率较高.     

优秀乒乓球运动员心理素质的自我分析

为了进一步与实证研究的结果相印证,采用质化研究的方法,对国家队顶尖级乒乓球运动员进行深度访谈并进行自我分析,结合研究者自身运动生涯的轨迹进一步探讨优秀乒乓球运动员的重要心理特质。结果表明：优秀乒乓球运动员心理素质包括表现性、乐观性、变通性、稳定性、探究性、自律性及工作专注等8项,这些心理素质对于乒乓球运动员的竞赛成绩以及专业发展有重要影响。     

我国青少年乒乓球运动员非智力因素研究

根据我国青少年乒乓球运动员特定的文化、环境特点,在我国非智力因素理论相关研究的基础上,运用文献资料、专家访谈、问卷调查和数理统计等方法,以八一队、山东队等5个乒乓球专业队10岁至17岁的青少年运动员为研究对象,分析非智力因素的差异性,为乒乓球运动员的训练和科学选材提供可靠依据。研究结果表明不同性别运动员中,成就动机、运动焦虑、运动自信心三个维度上存在显著性差异;不同年龄段运动员中,运动热情有非常显著的差异;不同训练年限的运动员中,运动独立性和运动坚持性两个维度存在显著性差异;不同级别运动员中,运动热情、注意稳定性和情绪稳定性三个维度有显著性差异。各级教练员根据乒乓球运动员非智力因素的差异性,从科学选材,到有侧重的加强青少年乒乓球运动员非智力因素的培养和强化,能在科学训练中更快更好的提升乒乓球竞技水平,缩短成才周期。     

论乒乓球运动的社会文化意义

随着社会文明的进步和现代人生活方式的改变,现代乒乓球运动的意义已不再仅仅限于体育与游戏的范畴,而越来越多地融入到社会文化之中。探讨了乒乓球运动的社会文化意义,即它是世界运动语言并体现民族文化特色;它体现了个性特点的张扬与人格精神的塑造;它的创新推动了其发展;它呈现了平民化的发展趋势并体现大众文化状况。     

Sequence-dependent rotation axis changes in tennis

The purpose of this study was to evaluate the role of rotation axes during a tennis serve. A motion capture system was used to evaluate the contribution of the potential axes of rotation (minimum inertia axis, shoulder-centre of mass axis and the shoulder-elbow axis) during the four discrete tennis serve phases (loading, cocking, acceleration and follow through). Ten ranked athletes (International Tennis Number 1–3) repeatedly performed a flat service aiming at a target on the other side of the net. The four serve phases are distinct and thus, each movement phase seems to be organised around specific rotation axes. The results showed that the limbs’ rotational axis does not necessarily coincide with the minimum inertia axis across the cocking phase of the tennis serve. Even though individual serving strategies were exposed, all participants showed an effect due to the cocking phase and changed the rotation axis during the task. Taken together, the results showed that despite inter-individual differences, nine out of 10 participants changed the rotation axis towards the minimum inertia and/or the mass axis in an endeavour to maximise external rotation of the shoulder to optimally prepare for the acceleration phase.     

我国女子乒乓球运动员个性特征研究

我国女子乒乓球运动员16项个性因素具有典型的项目特征，总体状况表现为在乐群性、聪慧性、稳定性等7个方面趋向高分特征，而在有恒性、敏感性、怀疑性等7个方面趋向低分特征。我国女子乒乓球运动员与女篮、女排运动员相比，个性表现更为热情活泼、自信好强，与女大学生相比，其个性特征表现得较为鲜明，性格更为成熟。我国女子乒乓球运动员的双重个性均属于适应型、外向型、安详机警型和果断型。     

Lower limb muscle activity during table tennis strokes

This study aimed to compare the muscle activity of lower limbs across typical table tennis strokes. Fourteen high-level players participated in this study in which five typical strokes (backhand top, forehand top, forehand spin, forehand smash, flick) were analysed. Surface electromyography activity (EMG) of eight muscles was recorded (gluteus maximus, biceps femoris, vastus medialis, vastus lateralis, rectus femoris, gastrocnemius medialis, gastrocnemius lateralis, soleus) and normalised to the maximal activity measured during squat jump or isometric maximal voluntary contractions. The forehand spin, the forehand top and the forehand smash exhibited significant higher EMG amplitude when compared with other strokes. Both biceps femoris and gluteus maximus were strongly activated during the smash, forehand spin and forehand top (from 62.8 to 91.7% of maximal EMG activity). Both vastii and rectus femoris were moderately to strongly activated during the forehand spin (from 50.4 to 62.2% of maximal EMG activity) whereas gastrocnemii and soleus exhibited the highest level of activity during the smash (from 67.1 to 92.1% of maximal EMG activity). Our study demonstrates that offensive strokes, such as smash or forehand top, exhibit higher levels of activity than other strokes.     

Scapulothoracic kinematics during tennis forehand drive

Scapular dyskinesis is recognized as an abnormality in the kinetic chain; yet, there has been little research quantifying scapular motion during sport tasks. Tennis forehand drives of eight highly skilled tennis players were studied to assess the scapulothoracic kinematics and evaluate repeatability using video-based motion analysis. Scapulothoracic downward/upward rotation, posterior/anterior tilt, and internal/external rotation were computed using an acromial marker cluster. On average, the upward rotation, anterior tilt, and internal rotation varied from 1° to 26°, from 7° to 32°, and from 42° to 100°, respectively, during the tennis forehand drive. During the backswing and forward swing phases of the forehand stroke, small changes were observed for the three scapular angle values, while all angles increased rapidly during the follow-through phase. This suggests that the tennis forehand drive may contribute to scapula dyskinesis, mainly due to the great amplitude in scapulothoracic anterior tilt and internal rotation observed during the follow-through phase. Knowledge of normal scapula motion during sport tasks performed at high velocity could improve the understanding of various sport-specific adaptations and pathologies.     

Effect of skill decomposition on racket and ball kinematics of the elite junior tennis serve

Whole body kinematics of the tennis serve have been reported extensively in the literature, yet comparatively less information exists regarding the kinematic characteristics of the swing and toss. In attempting to develop consistency in placement of the toss and racket trajectory, coaches will often decompose the serve and practice it in separate parts. A 22-camera VICON MX motion analysis system, operating at 250 Hz, captured racket, ball and hand kinematics of the serves of five elite junior players under three conditions. The conditions were flat first serves (FS) directed to a 1 × 1 m target bordering the ‘T’ of the deuce service box, a ball toss (BT) in isolation and a free swing (SW) in isolation. Players were instructed to perform BT and SW as in the FS. Paired t-tests assessed within-group differences in hand, racket and ball kinematics between the discrete skill and the two decomposed conditions. Vertical displacement of the ball at its zenith increased significantly during BT compared with the FS and temporal associations between racket and ball motion during the FS (r = 0.861) were affected during task decomposition. This study questions the pervasive use of task decomposition in the development of the tennis serve.     

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。