中外优秀男排选手前、后排扣球技术的比较研究

运用三维高速摄影方法对中外优秀男排选手前排扣球和后排扣球技术的比较分析 ,揭示了前排扣球与后排扣球的不同特征 ,后排扣球比前排扣球具有助跑速度快 ,前冲距离大 ,击球点高、肩速快、击球速度快的特征。     

The effect of ball-carrying technique and experience on sprinting in rugby union

There are several ways of carrying the ball in rugby union, which could influence the speed at which a player can run. We assessed 52 rugby players (34 males, 18 females) during a maximum sprint over 30 m without the ball, with the ball under one arm, and with the ball in both hands. Timing gates were used to measure time over the initial 10 m and the last 20 m. It has previously been reported (Grant et al., 2003) that running with the ball produces a slower sprinting speed than running without the ball. We hypothesized that the decrease in speed caused by carrying the ball would become less marked with the experience of the player. The male and female players were each divided into two groups: a "beginner" group that consisted of players in their first or second season and an "experienced" group that was composed of players who had played for more than two seasons. A 2 x 3 mixed-model analysis of variance was used to identify differences (P < 0.01) between the beginner and experienced groups in the three sprinting conditions. The times for the males for the first 10 m sprints without the ball, with the ball under one arm, and with the ball in both hands were 1.87 +/- 0.08 s, 1.87 +/- 0.08 s, and 1.91 +/- 0.1 s for the beginners, and 1.87 +/- 0.1, 1.88 +/- 0.1 and 1.88 +/- 0.12 for the more experienced players respectively. The times for the females for the first 10 m without the ball, with the ball under one arm, and with the ball in both hands were 2.13 +/- 0.16 s, 2.19 +/- 0.17 s, and 2.20 +/- 0.16 s for the beginners, and 2.03 +/- 0.12 s, 2.03 +/- 0.09 s, and 2.04 +/- 0.1 s for the more experienced players respectively. For the last 20 m of the 30-m sprint, there were differences between the different sprint conditions (P < 0.001) but no differences that were attributable to experience (P = 0.297). The times for the males over the last 20 m without the ball, with the ball under one arm, and with the ball in both hands were 2.58 +/- 0.19 s, 2.61 +/- 0.12 s, and 2.65 +/- 0.12 s for the beginners, and 2.59 +/- 0.12, 2.62 +/- 0.23, and 2.65 +/- 0.18 s for the more experienced players respectively. The times for the females over the last 20 m without the ball, with the ball under one arm, and with the ball in both hands were 3.25 +/- 0.38 s, 3.35 +/- 0.42 s, and 3.40 +/- 0.46 s for the beginners, and 3.04 +/- 0.32 s, 3.06 +/- 0.22 s, and 3.13 +/- 0.27 s for the more experienced players respectively. No gender-specific differences were detected. The results of this study suggest that practising sprints while carrying a ball benefits the early phase of sprinting while carrying the ball.     

脚击球技术在排球比赛中的运用

以2000～2001年“步步高杯”全国排球甲级联赛第4轮8个参赛队为统计对象，以中南大学南方排球队4名主力队员为实验对象，将脚击球技术运用到排素比赛中进行比较研究，表明脚击球技术在比赛中有较大的潜力可挖，当球飞行距离较短和起远距离低位球时脚击球成功率高于手击球。     

The use of physiological,anthropometric, and skill data to predict selection in a talent-identified junior volleyball squad

Abstract

The aim of this study was to determine whether physiological, anthropometric, and skill test results could discriminate between junior volleyball players of varying ability. Twenty-eight junior volleyball players competed for selection in a talent-identification volleyball programme. Participants underwent measurements of stature, standing reach stature, body mass, skinfold thickness, overhead medicine ball throw, vertical jump, spike jump, 5-m and 10-m speed, “T” test agility, maximal aerobic power, and passing, setting, serving, and spiking technique and accuracy. A discriminant analysis was conducted on the selected and non-selected groups to obtain a regression equation that could be used to predict selection in junior volleyball squads based on the dependent variables. Passing and serving technique were the only significant variables included in the discriminant analysis. Cross-validation results showed that 17 of 19 selected players (89.5%) and 5 of 9 non-selected players (55.6%) were correctly classified into selected and non-selected groups, respectively, providing an overall predictive accuracy of 78.6%. The results of this study demonstrate that selected skill test results (i.e. subjective coach evaluations of passing technique and serving technique), but not physiological and anthropometric data, discriminate between successful and unsuccessful talent-identified junior volleyball players. These results demonstrate the importance of developing passing and serving technique in talent-identified junior volleyball players.     

The use of physiological, anthropometric, and skill data to predict selection in a talent-identified junior volleyball squad

The aim of this study was to determine whether physiological, anthropometric, and skill test results could discriminate between junior volleyball players of varying ability. Twenty-eight junior volleyball players competed for selection in a talent-identification volleyball programme. Participants underwent measurements of stature, standing reach stature, body mass, skinfold thickness, overhead medicine ball throw, vertical jump, spike jump, 5-m and 10-m speed, "T" test agility, maximal aerobic power, and passing, setting, serving, and spiking technique and accuracy. A discriminant analysis was conducted on the selected and non-selected groups to obtain a regression equation that could be used to predict selection in junior volleyball squads based on the dependent variables. Passing and serving technique were the only significant variables included in the discriminant analysis. Cross-validation results showed that 17 of 19 selected players (89.5%) and 5 of 9 non-selected players (55.6%) were correctly classified into selected and non-selected groups, respectively, providing an overall predictive accuracy of 78.6%. The results of this study demonstrate that selected skill test results (i.e. subjective coach evaluations of passing technique and serving technique), but not physiological and anthropometric data, discriminate between successful and unsuccessful talent-identified junior volleyball players. These results demonstrate the importance of developing passing and serving technique in talent-identified junior volleyball players.     

Differences in ball speed and accuracy of tennis groundstrokes between elite and high-performance players

Abstract

The main aim of this study was to identify and compare ball speed and hitting accuracy of forehand and backhand groundstrokes between ATP professionals (elite) and high-performance youth players when shots were played cross-court and down the line to a target square. Six elite and seven high-performance tennis players volunteered to participate in the study. A Doppler-radar device and a digital video camera, operating at 120 frames per second, were used to measure ball speed and accuracy of forehand and backhand groundstrokes in the respective situation (cross-court and down the line). The results of 1040 measured groundstrokes indicate that the ball speed of the forehand and the backhand ground stroke was higher in the elite group when analysing (1) all valid shots, (2) the six fastest shots, and (3) the six most accurate shots (all P < 0.05). In addition, all players achieved a higher forehand speed compared with their backhand when balls were directed cross-court (P < 0.01). The participants demonstrated similar ability when considering accuracy of their groundstrokes (P > 0.05). However, a group difference for accuracy was identified when considering the six fastest forehand shots (P<0.05), and the forehand cross-court stroke was played more accurately than the backhand cross-court stroke by both groups (valid shots and six most accurate shots, P<0.05). Moreover, there was no evidence that players who impacted the ball faster were any less accurate than those who impacted the ball more slowly. Analyses for participants actually revealed a negative correlation between ball speed and mean radial error (accuracy) for the backhand down the line (r= ? 0.77, P<0.01). According to the results of this study, ball speed seems to be the determining factor that separates elite from sub-elite tennis players.     

浅析沙滩排球拦网技术的训练与运用

沙滩排球6大技术（发球、垫球、传球、扣球、拦网、防守）中,拦网是最容易学的一项技术,只要能跳,不触网就可以上去拦网了。所以初学沙滩排球的人经常会有拦网是最简单的技术的错觉。实际上拦网是一项和其他各项技术相比最复杂的技术,因为它的特点是拦网队员要在短短的瞬间从防守转为进攻,从被动转为主动,而完成这些都要在空中进行,所以难度较大,技术的要求也很高,而且拦网的好坏并不仅仅取决于身体素质和技术的好坏,很重要的一方面是在比赛中有针对性的临场运用。以下通过对第11届全运会沙滩排球比赛拦网统计的比较,对拦网这项技术在沙滩排球比赛中的应用、注意事项以及一些训练方法做一个分析和概括。     

论优秀女子足球运动员专项速度耐力综合测试模型的建立

本文从我国优秀女子足球运动员的训练与比赛实际出发，试图探讨建立符合实际的专项速度耐力综合测试模型。文章认为传统的测试方法因为大多是在无球状态下进行，存在一定的缺陷，特指出必须结合有球的速度耐力测试才更具有实践指导意义。     

The off-break and “doosra”: Kinematic variations of elite and sub-elite bowlers in creating ball spin in cricket bowling

This study sought to identify kinematic differences in finger-spin bowling actions required to generate variations in ball speed and spin between different playing groups. A 12-camera Vicon system recorded the off-spin bowling actions of six elite and 13 high-performance spin bowlers, and the “doosra” actions of four elite and two high-performance players. Forearm abduction and fixed elbow flexion in the bowling arm were higher for the elite players compared with the high-performance players. The elite bowlers when compared with the high-performance players delivered the off-break at a statistically significant higher velocity (75.1 and 67.1 km/hr respectively) and with a higher level of spin (26.7 and 22.2 rev/s respectively). Large effect sizes were seen between ball rotation, pelvic and shoulder alignment rotations in the transverse plane. Elbow extension was larger for elite bowlers over the period upper arm horizontal to ball release. Compared to the off-break, larger ranges of shoulder horizontal rotation, elbow and wrist extension were evident for the “doosra”. Furthermore, the “doosra” was bowled with a significantly longer stride length and lower ball release height. Although not significantly different, moderate to high effect size differences were recorded for pelvis rotation, elbow extension and elbow rotation ranges of motion.     

上海男子排球运动员大力跳发球技术动作的诊断

从国家男排部分上,海籍运动员的大力跳发球技术测试效果入手,分析与诊断影响其大力跳发球技．概动作的主要因素,并就发球抛球、发球速度的固定等两方面进行具体的分析与讨论。同时对两名优秀选手的腰背肌肉力量进行监测、综合评价其大力跳发球技术动作利弊特征,并做相关的比较研究。经运动学分析,总体上两名运动员的大力跳发球抛球时间偏短、击球点偏低,一造成共发球球速慢且失误率高等,并建设性的提出跳发球技术动作诊断应因人而异,最大限度地挖掘个人技术动作的局部潜优势。     

Does shortening the pitch make junior cricketers bowl better?

In order to get bounce and movement seam bowlers need to bowl the ball “into” the pitch. Standard deliveries by elite players are typically projected at around 7° below horizontal. In contrast, young players currently often need to release the ball almost horizontally in an effort to get the ball to bounce close enough to the batter. We anticipated that shortening the pitch could be a simple way to help young bowlers to release the ball at a better angle and with more consistency. Twenty county or best in club age group under 10 and under 11 seam bowlers were analysed bowling indoors on two different pitch lengths. They were found to project the ball on average 3.4° further below horizontal on a 16 yard pitch compared with a 19 yard pitch, while ball speed and position at release changed negligibly. Pitch length did not affect the consistency of the release parameters. The shorter pitch led to a ball release angle closer to that of elite bowlers without changing release speed, and this should enable players to achieve greater success and develop more variety in their bowling.     

信息量与认知负荷对羽毛球运动员视觉搜索特征的影响

选取14名羽毛球专业运动员和14名大学生初学者为被试,以羽毛球专项情境中对手即将回球的动作前情境图片预判为反应任务,探讨被试在不同信息量与认知负荷情况下知觉预判绩效及眼动特征。结果表明:运动员与初学者利用更多的信息来加快动作预判速度;运动员动作预判速度要快于初学者,二者在简单任务中的动作预判准确性优于复杂任务中的预判准确性;信息量主要影响运动员动作预判准确性。运动员视觉搜索的注视时间低于初学者;高信息量注视时间少于低信息量的注视时间,且运动员比初学者注视频率更少。运动员注视次数少于初学者;眼跳距离多于初学者;运动员注视轨迹比初学者更为集中。在视觉搜索分配上,运动员与初学者都主要关注球拍与持拍臂,但是在复杂任务与高信息量中,运动员比初学者更关注场上对手与场地位置关系。     

Prevalence of disordered eating in elite female athletes in team sports in Greece

ABSTRACT

The purpose of the study was to assess (a) the prevalence of disordered eating (DE) in elite female team sports players compared to non-athletes and (b) to compare DE prevalence in elite female players in basketball, volleyball and water polo. One hundred and seventy-five females were recruited (age 23.10?±?5.4, BMI 21.85?±?2.3?kg/m²), 53 were elite basketball players, 42 were elite volleyball players, 34 were elite water polo players and 46 were non-athletes. Participants completed the Eating Disorders Questionnaire (EDE-Q) and a physical activity questionnaire. The EDE-Q incorporates 36 statements which relate to the occurrence and frequency of key behaviours of eating disorders, under the following four subscales: Restraint, eating concern, shape concern and weight concern and a global score of disordered eating. No differences were found in the EDE-Q subscale score and global score between athletes and non-athletes. Only 6.2% of the total number of participants exhibited DE using the global score >2.3. Water polo players had significantly higher scores in the ‘eating concern’ subscale and in the frequency of key behavioural features of DE such as binge eating episodes and objective and subjective bulimic episodes, compared to volleyball and basketball players. In conclusion, team sport elite female players do not exhibit greater prevalence of DE compared to non-athletes. Water polo, a sport that emphasises leanness and control of body weight for international distinctions, is associated with a higher tendency to exhibit DE, when compared to other team sports.     

优秀男女排球运动员有效防守距离分析

从扣球的球速、运动员生理反应时等有关参数入手，对优秀男女排球运动员的防守有效距离进行理论分析与探讨，为我国排球运动防守训练水平的提高及丰富防守训练理论，提供一些理论方面的参考。     

羽毛球运动员专项情境中信息加工阶段速度研究

选择44名专业羽毛球运动员和12名羽毛球初学者为被试,以羽毛球比赛情境片段和两种刺激信号为素材,对优秀运动员知觉技能中快速反应的内存机制进行了实验性研究。结果表明:1)在羽毛球专项情境中,与初学者相比,优秀运动员并不是在所有的三个信息加工阶段都表现出较快的加工速度;2)专业运动员比初学者具有快速的刺激辨别,这一指标是评价羽毛球运动员与非运动员的有效指标;3)不同水平运动员在反应选择阶段没有显著的加工速度差异;4)与中等和初学者相比,高水平运动员具有快速的应答编程速度,应答编程阶段的加工速度是水平相近的优秀运动员的有效评价指标。     

Effects of contrasting colour patterns of the ball in the volleyball reception

The effects of three different colour patterns on the surface of volleyballs (versus that of a plain white ball) on the behaviour of a reception player were examined by presenting sidespin volleyball serves. Expert (n = 10) and novice (n = 10) volleyball players intercepted volleyballs projected straight at them or at an initial angle of 9.5 degrees outwards but eventually curving towards the players' original position. In the latter trajectories, players generally took one or more steps laterally before returning to the landing position of the ball. These excursion patterns were significantly more pronounced with the white balls than the coloured balls. Differences between balls of different colour combinations were also observed. The first finding supports the thesis that next to a prospective type of control, such as on-line maintenance of a certain spatiotemporal relationship between the player and the ball, properties of the ball itself allow prediction of the future path of the ball. Differences between types of colour patterns are explained within the framework of the between-colours wavelength contrasts of each type of ball.     

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.     

中国和古巴男排运动员双人拦网技术的比较

通过三维高速录像对中国和古巴两国男排运动员双人拦网技术动作的分析表明:当对方4号位强攻扣球时,2号位队员面对球网并步移动起跳拦网,3号位队员左肩斜对网跑步移动起跳空中转体拦网。古巴运动员拦网时重心腾空高,手臂与网垂直面夹角小,两臂主动用力前伸下压两手压腕罩球,躯干收腹呈"<"型,拦网攻击性强。     

Reliability and validity of two tests of soccer skill

Twenty-four players from the 1st/2nd (elite) and 24 players from the 3rd/4th (non-elite) university football teams were recruited to evaluate the Loughborough Soccer Passing Test (LSPT) and Loughborough Soccer Shooting Test (LSST) as tools to assess soccer skill. The LSPT requires players to complete 16 passes as quickly as possible. The LSST requires players to pass, control, and shoot the ball to targets on a full-sized goal. Participants completed two main trials each separated by at least one day. During both trials, the participants were given practice efforts before recording the mean of the next two (LSPT) or 10 (LSST) attempts as the performance score. For the LSPT, the mean time taken, added penalty time, and overall performance time were less in the elite players (elite: 43.6 s, s = 3.8; non-elite: 52.5 s, s= 7.4; P= 0.0001). For the LSST, there was no difference in the mean points scored per shot between groups (elite: 1.34, s = 0.46; non-elite: 1.28, s = 0.53). However, the elite players had higher mean shot speed (elite: 80 km h(-1), s = 4.5; non-elite: 74 km h(-1), s = 4.2; P < 0.0001) and performed each shot sequence faster (elite: 7.87 s, s= 0.29; non-elite: 8.07 s, s= 0.35; P= 0.037) than the non-elite players. Performance on both tests was more repeatable in elite players. In conclusion, the LSPT and LSST are valid and reliable protocols to assess differences in soccer skill performance.