The asymmetry of pectoralis muscles is greater in male prepubertal than in professional tennis players

It is generally accepted that preadolescents have a limited capacity to develop muscle hypertrophy in response to exercise compared with older populations; however, studies are scarce and conflicting. The main aim of the present study was to assess if playing tennis is associated with the hypertrophy of dominant pectoralis muscles (PM) in professional (PRO) and in prepubescent tennis players (PRE). A secondary aim was to assess if the degree of asymmetry of PM is greater in PRO than PRE. The volume of PM of both sides was determined using magnetic resonance imaging in 8 male PRO (21.9 years), 6 male PRE (11 years, Tanner 1–2) and 12 male non-active controls (6 adults: 23.5 years; and 6 prepubescents: 10.7 years, Tanner 1–2). PRO and PRE had 15 and 30% greater volume, respectively, in the dominant than in the contralateral PM (P?P?=?.34 in adults and 5%, P?=?.17 in children). The degree of side-to-side asymmetry in PM volume was greater in PRE than in PRO (P?相似文献   

The core musculature in male prepubescent tennis players and untrained counterparts: a volumetric MRI study

The effects of exercise on the core musculature have not been investigated in prepubescents. The main purpose of the present study was to determine the volume and degree of asymmetry of rectus abdominis, obliques and transversus abdominis, quadratus lumborum, iliopsoas, gluteus and paravertebralis muscles in prepubescent tennis players and in untrained boys. The muscle volume was determined using magnetic resonance imaging (MRI) in 7 male prepubescent tennis players and 10 untrained controls (mean age 11.0 ± 0.8 years, Tanner 1–2). After accounting for height and body weight as covariates, the tennis players had 14–34% greater volume than the controls in all the muscles analysed (P < 0.05) except in paravertebralis, dominant quadratus lumborum and non-dominant gluteus, which had similar volumes in both groups (P = NS). Compared to controls, the tennis players displayed a greater degree of asymmetry in quadratus lumborum and rectus abdominis (3% vs. 15%, P < 0.01 and 8% vs. 17%, P = 0.06, respectively). The level of asymmetry of obliques and transversus abdominis, iliopsoas, gluteus and paravertebralis muscles was similar in both groups (P = NS). In conclusion, tennis playing at prepubertal ages induces a selective hypertrophy of the core musculature and exaggerates the degree of asymmetry of quadratus lumborum and rectus abdominis compared to untrained boys.     

Morphology of the deltoid muscles in elite tennis players

Abstract

The aim of this study was to examine the deltoid muscle properties of the dominant and non-dominant arm of Greek professional male tennis players. Eight male tennis players (mean age 22.0 years, s = 3.2) were subjected to biopsy of the deltoid muscle of both arms. Adenosine triphosphate (ATPase) histochemistry and myosin heavy chain (MHC) composition were performed on the samples with homogenate electrophoresis. No significant differences were observed in the percentage of types I, IIa, IIab, and IIb muscle fibres between the deltoid muscles of the two arms. Types I, IIa, and IIx muscle fibres of the dominant and non-dominant deltoid muscles did not differ significantly for MHC isoform composition. Type IIab muscle fibres showed a similar cross-sectional area (CSA) percentage distribution between the two arms. The CSA percentage for types I, IIa, and IIb muscle fibers did not differ significantly between the dominant and the non-dominant arm. We conclude therefore that regular tennis training probably does not lead to any significant changes in the muscle fibre types of the dominant and non-dominant arms of elite tennis players.     

男网不同打法类型选手比赛中各阶段得分特征分析

采用文献资料法、录像观察法、数理统计法等,对不同打法类型的世界优秀男子网球选手在比赛中的不同阶段的得分特征进行分析,找出各打法类型运动员在比赛中的得分特点,分析得分的主要战术特征,旨在为我国网球运动员打法类型的培养及训练提供参考。     

A comparison of visual search strategies of elite and non-elite tennis players through cluster analysis

Considerable research has documented that successful performance in interceptive tasks (such as return of serve in tennis) is based on the performers’ capability to capture appropriate anticipatory information prior to the flight path of the approaching object. Athletes of higher skill tend to fixate on different locations in the playing environment prior to initiation of a skill than their lesser skilled counterparts. The purpose of this study was to examine visual search behaviour strategies of elite (world ranked) tennis players and non-ranked competitive tennis players (n = 43) utilising cluster analysis. The results of hierarchical (Ward’s method) and nonhierarchical (k means) cluster analyses revealed three different clusters. The clustering method distinguished visual behaviour of high, middle-and low-ranked players. Specifically, high-ranked players demonstrated longer mean fixation duration and lower variation of visual search than middle-and low-ranked players. In conclusion, the results demonstrated that cluster analysis is a useful tool for detecting and analysing the areas of interest for use in experimental analysis of expertise and to distinguish visual search variables among participants’.     

振动训练对网球运动员正手、双手反手击球的影响

振动训练以其独特的功效,在训练学领域由于能帮助运动员提高训练水平而备受教练员的关注。以网球运动员上肢作为研究对象,探讨振动训练对网球运动员正手击球和双手反手击球产生的影响。结果显示:①振动组运动员正手击球时的爆发力,在小阻力和大阻力下有明显提高,出手速度在小阻力下有明显提高;非振动组运动员中阻力下击球速度有明显提高。②振动训练能使小阻力和大阻力双手反手击球时的爆发力得到明显提高,同时在大阻力下的反手出手速度明显提高;非振动组运动员在大阻力下的爆发力得到提高。③振动训练在该实验中是有效的干预手段,在一定程度上是传统力量训练的补充。     

Motivational profiles in table tennis players: Relations with performance anxiety and subjective vitality

ABSTRACT

Research has suggested the need to use a person-centred approach to examine multidimensionality of motivation. Guided by self-determination theory (Deci & Ryan, 1985), the primary aim of the present study was to examine the motivational profiles in table tennis players and their composition by gender, country, training status, and competition levels (from recreational to international). The secondary aim was to examine the differences in performance anxiety and subjective vitality across the motivational profiles. Participants were 281 table tennis players from multiple countries, mostly the U.S. and China. Hierarchical and nonhierarchical cluster analyses were conducted and showed three motivational profiles with distinct quantity and quality: “low”, “controlled”, and “self-determined”. Chi-square tests of independence demonstrated significant differences in their cluster membership by country, formal training with a coach, and competition levels, but not gender. MANCOVA results indicated differences in performance anxiety and subjective vitality across the motivational profiles, in which the controlled profile had the greatest anxiety symptoms. These differences are attributed to the quality over quantity of motivation, which have meaningful implications for table tennis coaches and sport psychology consultants to diagnose and intervene with players in order to reduce their performance anxiety and improve their well-being.     

Scapular motion adaptations in junior overhead athletes: a three-dimensional kinematic analysis in tennis players and non-overhead athletes

Adult overhead athletes without a history of shoulder injury show scapular adaptations. There is a lack of detailed assessment of scapular kinematics in junior overhead athletes. This study aims to investigate three-dimensional scapular kinematics in junior overhead athletes. We recruited a total of 20 junior tennis players and 20 healthy children without participation in any overhead sports in this study. Bilateral scapular kinematic data were recorded using an electromagnetic tracking device for scapular plane glenohumeral elevation. The data were further analysed at 30°, 45°, 60°, 90° and 120° during glenohumeral elevation and lowering. Statistical comparisons of the data between groups (junior overhead athletes and non-overhead athletes) and sides (serve dominant and non-dominant shoulders of the overhead athletes) were analysed with the ANOVA. Comparisons showed that, in general, the scapula was more upwardly rotated and anteriorly tilted in overhead athletes when compared to non-overhead athletes, however there was no side-to-side differences when serve dominant and non-dominant shoulders compared in junior overhead athletes. The serve dominant arm of junior overhead athletes had alternations in scapular kinematics when compared with the non-overhead athletes. These findings provide clinical evaluation implications and the need for clinicians to assess for potential adaptations in junior overhead athletes.     

中外女子网球优秀单打选手发球技术特点的比较研究

运用文献资料法、观察法和比较分析法等,分别对我国女子优秀选手和国外女子优秀选手比赛中的发球进行观察统计,对她们发球技术特点进行比较分析,找出我国选手的优势与不足,旨在为我国女子网球发球水平的提高提供理论依据。     

The effect of ball compression on the match-play characteristics of elite junior tennis players

The purpose of this article was to examine the effect of equipment scaling, through the modification of tennis ball compression, on elite junior tennis players (aged 10 years) within a match-play context. The two types of ball compressions that were compared were the standard compression (the normal ball) and 75% compression (termed the modified ball). Ten boys and 10 girls participated in the study. Participants were stratified into pairs based on their Australian Age Ranking and gender. Each pair played two two-set matches: one match with standard compression balls and one match with modified balls. The characteristics of each match were analysed and compared. The results showed that the use of the modified ball increased rally speed, allowed players to strike the ball at a lower (more comfortable) height on their groundstrokes and increased the number of balls played at the net. Ball compression had no effect on the relative number of winners, forehands, backhands, first serves in and double faults. The results are discussed in relation to skill acquisition for skilled junior tennis players.     

从十二运网球赛事看我国网球现存问题

通过对第12届全国运动会网球项目比赛的现场调研发现,项目布局失衡、队伍分层严重、经费普遍紧张、后备力量不足等问题制约着中国网球的进一步发展,针对上述问题展开分析,并提出相应的建议。     

运动表象能力对高水平网球运动员接发球准确性的影响

目的:旨在考察表象能力如何影响网球中运动表象训练后的运动能力提高。方法:将熟练的网球运动员按照他们的运动表象问卷(MIQ)得分被分为三组(强表象组、弱表象组、对照组)。在前测中,被试者对特定的目标接十五个发球。在十五个回合中,身体训练中穿插了运动表象训练。每个回合都由两组实验构成,十五个想象性实验和十五个身体的实验。一部分被试者被要求使用内部视觉表象(强表象组和弱表象组)。而另一些被试者则接受了阅读任务(控制组)。结果:被试者们在48小时后,接受了一项与前测相似的后测。结果显示,运动表象训练提高了接发球的能力,而这种提高在强表象者身上比在弱表象者身上的效果更加明显。     

新规则、新赛制下中外乒乓球运动员的战术应用比较

采用录像观察法和三段分析法,对国外优秀乒乓球运动员男子10人,女子11人共47场比赛进行分析,在此基础上结合张晓蓬(2004)的研究对中外优秀乒乓球运动员在新规则和新赛制下的战术应用情况进行对比分析。结果发现中国运动员在三段中的得分率明显高于国外选手,但在发球抢攻段的使用率较国外运动员低。研究还发现,国外男、女选手在三段的大多数指标中没有表明出明显的差异。男选手的技术优势主要体现在接发球段的得分能力上。     

世界优秀网球运动员发球落点分布区域分析

采用文献资料法、影像分析法、数理统计法,对世界优秀网球运动员在2009年澳大利亚网球公开赛中的每个发球所在区域的落点进行统计分析,归结出世界优秀网球运动员发球落点的区域分布规律,旨在为推动网球发球技术和质量的提高以及为网球运动员和广大网球爱好者提供参考依据。     

优秀网球运动员身高、体重和克托莱指数特征的研究

对ATP、WTA年终排名前50名的优秀网球运动员的身高、体重和克托莱指数特征进行了统计分析，探讨世界优秀网球运动员身高、体重和克托莱指数置信区间的特点及其身高与体重的回归方程，旨在为网球运动选材与运动训练提供理论参考。     

乒乓球女子横板“弧快”打法技战术特征分析

以世界优秀女子一线横板弧圈球结合快攻型打法5名乒乓球选手为研究对象,采取录像观察法、数理统计法等对其2010~2012年间参加的50场国际比赛录像进行技战术统计与分析,通过对女子横板＂弧快＂打法方法的技战术特征分析得出＂弧快＂打法选手发抢段使用率、得分率均为良好,发球和发球抢攻战术是发抢段主要得分手段,发球后控制技术也具有一定得分实力;接抢段使用率、得分率都为优秀,接发球、接发球抢攻、接球后抢攻是接抢段主要得分手段;其相持段使用率保持在良好水平,得分率为及格,该打法相持段反手得分能力突出。     

穴位艾灸对增进网球队员肌肉力量训练效果的研究

观察艾灸足三里、肾俞穴对网球队员肌肉力量的影响。方法：24名队员按配对设计分为对照组和艾灸组。两组进行相同的体能训练,艾灸组接受艾灸足三里穴和肾俞穴处理。分别于实验前和实验8周后测定两组握力、背力、大腿力、前臂围度、前臂皮褶厚度、大腿围度、大腿皮褶厚度。计算前臂比肌力、大腿比肌力。结果：实验前两组间比较上述各项指标无显著差异（P〉0．05）。实验8周后,艾灸组上述指标除背力外均高于对照组,两组间比较呈显著性差异（P〈0．05）：且实验后艾灸组和对照组的握力、大腿力、前臂比肌力、大腿比肌力均高于实验前（P〈0．05）。结论：体能训练可以提高肌肉力量,同时也说明艾灸足三里、肾俞穴可协同体能训练增强肌肉力量,提高运动能力。     

对中国乒乓球队优秀女子左手横板运动员的技战术分析

对我国优秀乒乓球运动员王楠和郭跃在各大比赛中的技战术运用情况进行分析,旨在为中国乒乓球运动员在今后的训练中提供参考依据。     

对世界优秀乒乓球女双选手李恩实/石恩美的技战术分析与研究

世界优秀乒乓球女子双打选手李恩实／石恩美(韩国)近年来在世界大赛保持着较好的战绩，是中国乒乓球队女双的头号劲敌。通过对她们的发球、发球抢攻、接发球段和相持段的技、战术特点进行分析，以期为中国乒乓球女双备战国际大赛提供参考。     

Expectancy effects in tennis: The impact of opponents' pre-match non-verbal behaviour on male tennis players

Abstract

In this study, we examined the impact of a male opponent's pre-match body language and clothing (general vs. sports-specific) on how his performances were judged by an observer. Forty male tennis players viewed videos of a male target tennis player warming up and then observed playing footage of the target. Each participant viewed the target player warming up displaying one of four combinations of body language and clothing (positive body language/tennis-specific clothing; positive body language/general sportswear; negative body language/tennis-specific clothing; negative body language/general sportswear). Participants rated the performance of the tennis player and gave their perceptions of the likely outcome of a tennis match with the target player. Analyses of variance indicated that clothing and body language had an interactive effect on both outcome expectations and ratings of performance. The findings support the contention that the initial impressions athletes form of their opponents can influence the way in which they judge the performances of opponents and their perceived likelihood of success against the same opponents.