Identifying swimmers as water-polo or swim team-mates from visual displays of less than one second     

Kylie A. Steel  Roger D. Adams  Colleen G. Canning 《Journal of sports sciences》2013,31(11):1251-1258

Abstract

Opportunities for ball passing in water-polo may be brief and the decision to pass only informed by minimal visual input. Since researchers using point light displays have shown that the walking or running gait of familiars can be identified, water-polo players may have the ability to recognize team-mates from their swimming gait. To test this hypothesis, members of a water-polo team and a competition swim team viewed two randomized sets of video clips, each less than one second long, of swimmers from both teams sprinting freestyle past a fixed camera. The arm stroke clip sequence showed only the upper body, and the kick sequence showed only the lower body. After viewing each video clip, observers rated their level of certainty as to whether the swimmer presented was a team-mate or not. Discrimination was significantly above chance in both groups. Water-polo players were better able to identify team-mates from their kick, whereas swimmers were better able to do so by viewing arm stroke. Our results suggest that, as with walking and running gait, small amounts of visual information about swimmers can be used for recognition, and so raise the possibility that specific training may be able to improve team-mate classification in water-polo, particularly in newly formed teams.  相似文献   

A field simulation study of the effectiveness of penalty kick strategies in soccer: Late alterations of kick direction increase errors and reduce accuracy     

John Van Der Kamp 《Journal of sports sciences》2013,31(5):467-477

Abstract

This field experiment investigated the relative merits of approaching the penalty kick with either a keeper-independent or keeper-dependent strategy. In the keeper-independent strategy, the shooter selects a target location in advance and disregards the goalkeeper's actions during the run-up. In the keeper-dependent strategy, the shooter makes a decision resting on the anticipation of the goalkeeper's movements during the run-up. Ten intermediate-level soccer players shot at one of two visually specified targets to the right and left side of the goal. In the keeper-independent strategy condition, participants were told that the visually specified target would not change. In the keeper-dependent strategy condition, participants were told that in half of the trials the visually specified target would change side at different times before ball contact, indicating that the direction of the kick needed to be altered. The results showed that penalty-taking performance was apt to be less than perfect in the keeper-dependent strategy condition. A decrease in the time available to alter kick direction resulted in a higher risk of not only an incorrect but also inaccurate shot placement. It is concluded that anticipating the goalkeeper's movements may degrade penalty kick performance, mainly due to insufficient time to modify the kicking action.  相似文献   

Early visual cues associated with a directional place kick in soccer     

Adrian Lees  Liam Owens 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):125-134

The purpose of this paper was to establish postural cues in kicking that may be of use to goalkeepers. Eight male soccer players (age 20.5 ± 1.1 yrs; height 1.78 ± 0.053 m; mass 75.18 ± 9.66 kg) performed three types of kick: a low side-foot kick to the left hand corner of the goal, a low side-foot kick straight ahead, and a low instep kick straight ahead. Kicks were recorded by an optoelectronic motion analysis system at 240 Hz. At kicking foot take-off (about 200 ms before ball contact) the variables which were significantly different and could act as cues were support foot progression angle, pelvis rotation, and kicking hip and ankle flexion. The support foot progression angle was considered to be the most valuable of these variables as its angle coincided with the direction of ball projection. The other variables were less clear in their interpretation and so less valuable for a goalkeeper to use for decision making. Cues appearing after support foot contact were thought unlikely to be of value to a goalkeeper in their decision making. These include kicking leg knee flexion angle, and support leg shank and thigh angles.  相似文献   

旋风脚支撑腿膝关节的受力及损伤机制分析     

石晓龙 《搏击·武术科学》2012,(9):54-56

旋风脚在武术竞技套路中是最常见且难度系数较其他腾空动作要高的腾空动作之一,是在武术套路中经常被采用的一种腾空动作,因此运动员的受伤概率相对较多.文章通过对旋风脚支撑腿膝关节的受力及损伤机制进行分析,为习练者提供正确的训练方法,以预防旋风脚因支撑腿膝关节的错误受力而受到的损伤.  相似文献   

对跆拳道踢靶训练的剖析     

孟强 《四川体育科学》2012,(5):49-53

通过专家访谈、文献资料调研等方法结合教学训练实际,分析了跆拳道踢靶训练中的安排设计问题,探讨了以腿法技术进行踢靶训练中的方法问题,提出了踢靶训练的控制与原则,以期为跆拳道的技术训练提供参考。  相似文献   

法国世界杯足球赛角球进攻战术分析   总被引：9，自引：0，他引：9  

陈杰 《体育与科学》1998,(6)

现代足球比赛中,各队对防守愈加重视,给进攻带来困难。在刚刚结束的第16届世界杯足球赛上,许多球队给进攻赋予新的变化,角球进攻是其中的一个方面。本文通过对本届杯赛角球进攻战术的研究分析,发现现代足球比赛中角球进攻的一些基本特点,寻找出一些较有实效的战术配合形式,如角球罚向的区域、球的运行轨迹、门前争点的位置及争点的方式、攻门的方式等。期望学习和借鉴世界强队在角球进攻战术组织方面的长处,帮助改进训练,提高角球进攻的实战效果。  相似文献   

竞赛速度条件下游泳体位与打腿技术的变化趋势与评价     

狄建 《西安体育学院学报》2003,20(5):54-56

应用阻力与速度的平方成正比定律[1][2],审视在竞赛速度条件下游泳体位与打腿配合技术。认为身体水中姿态与打腿技术的合理性与否在于通过技术动作所产生的推进阻力纯值的大小来给予评价。以此为依据,提出在竞赛条件下,游泳体位姿态与打腿配合技术相关的两种新技术观点:对水中人体姿态流线型的新诠释;快频率、小幅度打腿技术在竞赛速度条件下对水中游泳体位的影响。  相似文献   

2007亚洲杯定位球战术得分基本特征的分析     

杨向军  翟丰  曹大伟 《九江师专学报》2008,(3):94-97

本文采用文献资料、录象观察及数理统计等方法,通过对2007亚洲杯32场比赛28个利用定位球得分的进球,其所处的的比赛时段、进攻的配合、罚球和传中的区域及进球的国家分布等基本特征进行统计分析,指出本届杯赛定位球得分的基本技战术特征,可以作为我国国家队备战亚洲球队时在定位球方面的参考。  相似文献   

多媒体技术在腾空旋风脚360°教学过程中的应用探析     

王在传 《铜仁学院学报》2008,10(6):122-123

腾空旋风脚360°属于长拳当中国家A级高难度动作,技术结构复杂且难于掌握。其高飘的腿法和优美的腾空旋身法能够充分体现武术运动自身的难美性特点。应用多媒体技术对腾空旋风脚360°技术动作进行运动学分析,找出影响动作的主要因素,确立正确的技术概念,弥补人的感知所带来的不足,为科学的安排教学和训练提供一些参考。  相似文献   

The development of a method for identifying penalty kick strategies in association football     

Benjamin Noël  Philip Furley  John van der Kamp  Matt Dicks  Daniel Memmert 《Journal of sports sciences》2015,33(1):1-10

Penalty takers in association football adopt either a keeper-independent or a keeper-dependent strategy, with the benefits of the keeper-independent strategy presumed to be greater. Yet, despite its relevance for research and practitioners, thus far no method for identifying penalty kick strategies has been available. To develop a validated and reliable method, Experiment 1 assessed characteristics that observers should use to distinguish the two strategies. We asked participants to rate 12 characteristics of pre-recorded clips of kicks of penalty takers that used either a keeper-independent or keeper-dependent strategy. A logistic regression model identified three variables (attention to the goalkeeper, run-up fluency and kicking technique) that in combination predicted kick strategy in 92% of the penalties. We used the model in Experiment 2 to analyse prevalence and efficacy of both the strategies for penalty kicks in penalty shoot-outs during FIFA World Cups (1986–2010) and UEFA Football Championships (1984–2012). The keeper-independent strategy was used much more frequently (i.e., 78–86%) than the keeper-dependent strategy, but successes did not differ. Penalty takers should use both the strategies to be less predictable. Goalkeepers can use the developed model to improve their chances to succeed by adjusting their behaviour to penalty takers’ preferred penalty kick strategy.  相似文献