Biomechanical analysis of the “waiter’s serve” on upper limb loads in young elite tennis players

Waiter’s serve (WS) is a specific tennis serve posture frequently observed in young players, and commonly considered as a technical error by tennis coaches. However, biomechanical impact of WS is unknown. The aims of this study were to identify the potential consequences of WS in young elite players relating to performance and injury risk, and to explain the kinematic causes of WS. Serve of 18 male junior elite players (Top 10 national French ranking, aged 12–15 years) was captured with a 20 camera, 200?Hz VICON MX motion analysis system. Depending on their serve technique, the players were divided into two groups (WS versus Normal Serve [NS]) by experienced coaches. Injury data were collected for each player during a 12-month-period following the motion capture. Normalized peak kinetic values of the dominant arm were calculated using inverse dynamics. In order to explain WS posture, upper limb kinematics were calculated during the cocking and the acceleration phases of the serve. Shoulder internal rotation torque, wrist proximal and anterior forces (P?P?P?相似文献   

A kinematic comparison of the overhand throw and tennis serve in tennis players: How similar are they really?

Tennis coaches often use the fundamental throwing skill as a training tool to develop the service action. However, recent skill acquisition literature questions the efficacy of non-specific training drills for developing complex sporting movements. Thus, this study examined the mechanical analogy of the throw and the tennis serve at three different levels of development. A 500 Hz, 22-camera VICON MX motion capture system recorded 28 elite female tennis players (prepubescent (n = 10), pubescent (n = 10), adult (n = 8)) as they performed flat serves and overhand throws. Two-way ANOVAs with repeated measures and partial correlations (controlling for group) assessed the strength and nature of the mechanical associations between the tasks. Preparatory mechanics were similar between the two tasks, while during propulsion, peak trunk twist and elbow extension velocities were significantly higher in the throw, yet the peak shoulder internal rotation and wrist flexion angular velocities were significantly greater in the serve. Furthermore, all of these peak angular velocities occurred significantly earlier in the serve. Ultimately, although the throw may help to prime transverse trunk kinematics in the serve, mechanics in the two skills appear less similar than many coaches seem to believe. Practitioners should, therefore, be aware that the throw appears less useful for priming the specific arm kinematics and temporal phasing that typifies the tennis serve.     

‘If you miss the ball,you look like a total muppet!’ Boys investing in their bodies in physical education and sport

Connections have been drawn between masculinity, muscularity and physical or social status in sport. Not only are sporting bodies often related to masculinity but also to whiteness, leading to the devaluing of Asian boys' bodies and sporting experiences. This paper draws on three British Asian teenage boys' visual and verbal narratives to enquire how they negotiate these connections in their physical education and recreational sport experiences. Bourdieu's notion of capital is used to make sense of boys' ways of investing in their bodies to manage their status in school. Drawing from focus-group interviews which used participant-driven photography and photo elicitation techniques, the research indicates how three boys invested in their bodies by doing particular types of physical activity that would enable them to develop muscularity, fitness and/or motor competence, to attain or retain physical and social capital in school. Along the way, they add pertinent comments on the intersections of masculinity and ethnicity in constructing and performing a sporting body.     

‘We are all Foxes Now’: sport,multiculturalism and business in the era of Disneyization

On Monday 2 May 2016, a little heralded, medium-sized, provincial soccer club, Leicester City, one with no record of league titles in 132 years of trying, no European heritage of any note, and no major expenditure on players, won the English Premier League (EPL) title. This astonishing outcome is at odds with the development of monetised late-modern European club soccer. A select group of clubs with a global ‘reach’, owned and funded by foreign capital, have increasingly dominated the EPL since its formation in 1992. Leicester City’s triumph was also notable because Leicester is regarded as a settled multi-cultural city. The title win was widely interpreted as a vehicle for promoting racial integration, as well as celebrating positive owner/fan identities, civic pride, and traditional sporting values over the ethos of business. This paper explores these issues and what the Leicester victory meant to local supporters, and to the city.     

The influence of the hand’s acceleration and the relative contribution of drag and lift forces in front crawl swimming

The aim of this study was to assess the effect of the hand’s acceleration on the propulsive forces and the relative contribution of the drag and lift on their resultant force in the separate phases of the front crawl underwater arm stroke. Ten female swimmers swam one trial of all-out 25-m front crawl. The underwater motion of each swimmer’s right hand was recorded using four camcorders and four periscope systems. Anatomical landmarks were digitised, and the propulsive forces generated by the swimmer’s hand were estimated from the kinematic data in conjunction with hydrodynamic coefficients. When the hand’s acceleration was taken into account, the magnitude of the propulsive forces was greater, with the exception of the mean drag force during the final part of the underwater arm stroke. The mean drag force was greater than the mean lift force in the middle part, while the mean lift force was greater than the mean drag force in the final part of the underwater arm stroke. Thus, swimmers should accelerate their hands from the beginning of their backward motion, press the water with large pitch angles during the middle part and sweep with small pitch angles during the final part of their underwater arm stroke.     

The effect of normal load force and roughness on the dynamic traction developed at the shoe–surface interface in tennis

During tennis-specific movements, such as accelerating and side stepping, the dynamic traction provided by the shoe–surface combination plays an important role in the injury risk and performance of the player. Acrylic hard court tennis surfaces have been reported to have increased injury occurrence, partly caused by increased traction that developed at the shoe–surface interface. Often mechanical test methods used for the testing and categorisation of playing surfaces do not tend to simulate loads occurring during participation on the surface, and thus are unlikely to predict the human response to the surface. A traction testing device, discussed in this paper, has been used to mechanically measure the dynamic traction force between the shoe and the surface under a range of normal loading conditions that are relevant to real-life play. Acrylic hard court tennis surfaces generally have a rough surface topography, due to their sand and acrylic paint mixed top coating. Surface micro-roughness will influence the friction mechanisms present during viscoelastic contacts, as found in footwear–surface interactions. This paper aims to further understand the influence micro-roughness and normal force has on the dynamic traction that develops at the shoe–surface interface on acrylic hard court tennis surfaces. The micro-roughness and traction of a controlled set of acrylic hard court tennis surfaces have been measured. The relationships between micro-roughness, normal force, and traction force are discussed.     

Motor adaptation in complex sports – The influence of visual context information on the adaptation of the three-point shot to altered task demands in expert basketball players

Abstract

We examined the influence of visual context information on skilled motor behaviour and motor adaptation in basketball. The rules of basketball in Europe have recently changed, such that that the distance for three-point shots increased from 6.25 m to 6.75 m. As such, we tested the extent to which basketball experts can adapt to the longer distance when a) only the unfamiliar, new three-point line was provided as floor markings (NL group), or b) the familiar, old three-point line was provided in addition to the new floor markings (OL group). In the present study 20 expert basketball players performed 40 three-point shots from 6.25 m and 40 shots from 6.75 m. We assessed the percentage of hits and analysed the landing position of the ball. Results showed better adaptation of throwing performance to the longer distance when the old three-point line was provided as a visual landmark, compared to when only the new three-point line was provided. We hypothesise that the three-point line delivered relevant information needed to successfully adapt to the greater distance in the OL group, whereas it disturbed performance and ability to adapt in the NL group. The importance of visual landmarks on motor adaptation in basketball throwing is discussed relative to the influence of other information sources (i.e. angle of elevation relative to the basket) and sport practice.     

A coaches’ perspective on the contribution of anthropometry,physical performance,and motor coordination in racquet sports

ABSTRACT

Differences and similarities between table tennis and other racquet sports exist, but are not well documented in the literature, in spite of the relevance for talent identification. In this study we aimed at identifying the key characteristics of table tennis in comparison with tennis and badminton based upon a survey in coaches. A total of 177 licensed coaches from all across the world and with diverse professional backgrounds completed a survey on anthropometric measures, physical performance, and motor coordination skills. On a scale from 1 to 10, coaches indicated to what extent a talent characteristic was important for their sport. MANOVA identified key differences as well as similarities between all three racquet sports and a subsequent discriminant analysis allocated coaches correctly for table tennis, tennis, and badminton 81.01%, 55.6%, and 71.4% respectively. Our results show that table tennis and other racquet sport coaches are well aware of differences between the racquet sports and also the importance and value of testing and assortment of skill components. These findings can assist coaches in future talent orientation and transfer in racquet sports.     

‘The influence of overseas coaching and management on the occupational subculture of English professional soccer: views from the dugout’

It is generally acknowledged that expatriate British players and coaches were instrumental in soccer’s radiant global diffusion and that different technical and tactical emphases developed according to particular geographical locations and cultural milieu. As the twentieth century unfolded, the trend reversed with increased inward flows of elite foreign playing and coaching labour challenging the distinctive and erstwhile dominant occupational culture of the English game. This paper explores the dynamics and tensions of subcultural modification and adaptation at the British: migrant coaching talent interface. Owing to issues associated with access, the occupational subculture of elite-level football is impenetrable to most researchers. Previous employment in professional soccer allowed this author to overcome such impediments, permitting access to a range of high-status national and international players and coaches (n = 25) affecting and affected by occupational subcultural change. This enabled a distinctive research platform combining insider knowledge and grounded experience with academic orthodoxy. The paper is built upon primary data collected in semi-structured interviews and critical analysis of emerging themes. In doing so, it offers a fresh dimension to understanding the impact of globalization on elite professional English soccer. Key findings indicated the opinion of British coaches on the impact of this foreign influx polarized. Although many demonstrated an enlightened standpoint, adopting innovative practices introduced by overseas coaching talent, these views were counter-balanced by evidence of a myopic arrogance bordering on xenophobic resistance to change in what now has to be considered the global rather than the ‘English’ game.     

“Good,better, creative”: the influence of creativity on goal scoring in elite soccer

This study investigated the level of creativity of goals scored in football. Therefore, all goals in the Football FIFA World Cup 2010 and 2014, as well as the Football UEFA Euro 2016 were qualitatively examined. Three Football experts evaluated the last eight actions before each goal using a creativity scale ranging from 0 to 10 (0 = not creative, 10 = highly creative) of all goals scored via open play (311 goals in 153 matches). Level of creativity was revealed using an Analysis of Variance and the frquency of high highly creative goals using a Kruskall- Wallis Test. The results showed that the closer the actions to a goal, the more creative they were evaluated. Teams that advanced to the later rounds of the tournament demonstrated greater creativity than teams that failed to do so. High creativity in the last two actions before the actual shot on goal proved to be the best predictor for game success. In conclusion, this study is the first one to show that creativity seems to be a factor for success in high level football. Thereby it provides an empirical basis for the ongoing debate on the importance of creativity training in football.     

Developing ‘good buggers’: global implications of the influence of culture on New Zealand club rugby coaches’ beliefs and practice

Abstract

Despite recognition of how experience shapes sport coaches’ beliefs and practice empirical investigation into how this occurs is limited. This article redresses this gap in the literature by presenting the findings of a study that inquired into the influence of culture on three New Zealand rugby coaches’ beliefs and practice to identify the powerful influence of interaction between a ‘local’ traditional culture of club rugby in New Zealand shaped by the resilient ‘amateur ideal’, intensified by the perceived threat of professional rugby and the global culture of the sport industry to club rugby.     

‘Discipline Your Ladies … So They Become Independent’: A Discourse on the Beginnings of Women’s Skiing in the Black Forest,Germany

Abstract

The Black Forest is considered to be the cradle of skiing in Germany. In 2016, the 125th anniversary of the beginning of skiing in the Black Forest is being celebrated. Over the decades, skiing developed into a very popular sport for men and women in Germany and spread to the Alps. Presently, the German Ski Federation (Deutscher Skiverband, DSV) has over 500,000 members, about 40% being women. This paper will concentrate on the first decades of women’s skiing in the Black Forest until the First World War. To present a wider picture, in some sections, it will be necessary to relate to other parts of Germany. A special focus will be put on competitive skiing, skiing as a social event and the discourse about women’s ski clothes.     

Sex,sport and justice: reframing the ‘who’ of citizenship and the ‘what’ of justice in European and UK sport policy

Universalist claims are often made about sport which is, as a consequence, increasingly written into national and international policy as an entitlement of citizenship or even human right. Further, in most countries physical education (PE) is a compulsory component of children's education, and sport is seen as central to this. Consequently, in the interests of justice sport must aspire to be egalitarian, that is, relevant to and meaningful for boys and men, and girls and women. In this context three fundamental questions are asked in relation to sport: (1) Do all citizens want to participate? (2) Who counts as a citizen? and (3) What are justice and equality? Feminist political and citizenship theory particularly the work of Pateman, Lister and Fraser is used to explore these questions and interrogate the ‘who’ of citizenship and the ‘what’ of justice in relation to framing sport policy in Europe and the UK. It is argued that notwithstanding the extensive use of the Council of Europe definition of sport,¹1. ‘“Sport” means all forms of physical activity which, through casual or organised participation, aim at expressing or improving physical fitness and mental well-being, forming social relationships or obtaining results in competition at all levels' (CE, 1992 CE. (1992/2001). European sports charter. Retrieved from https://wcd.coe.int/ViewDoc.jsp?Ref=Rec(92)13&;Sector=secCM&;Language=lanEnglish&;Ver=rev&;BackColorInternet=9999CC&;BackColorIntranet=FFBB55&;BackColorLogged=FFAC75 [Google Scholar]–2001 CE. (1992/2001). European sports charter. Retrieved from https://wcd.coe.int/ViewDoc.jsp?Ref=Rec(92)13&;Sector=secCM&;Language=lanEnglish&;Ver=rev&;BackColorInternet=9999CC&;BackColorIntranet=FFBB55&;BackColorLogged=FFAC75 [Google Scholar]). and despite or even because of the widespread adoption of the language of gender equality and gender mainstreaming, although formal sport citizenship rights might be accorded to all individuals and regarded as gender neutral, this masks a discourse of androcentric sport citizenship. This has captured European and UK sport policy and provision and is hindering further progress towards gender justice in sport and therefore PE. Given the universal and compulsory aspirations of sport particularly within PE, gender justice should be conceptualised not only as cultural recognition, political representation and economic redistribution within the normalised frame of competitive performance sport or ‘sport for sports sake’; but also as a critical meta-political remapping and reframing of sport as sport and physical recreation or ‘sport for all’.     

Rattle Running,Dry Wrestling,and Boxing in … Opera,or Regional Sports and Games in the Historical and Cultural Tradition of Eastern Europe

Abstract

The article is a heartfelt plea to both Western and Eastern European sports historians to take full account of the rich sporting history of the eastern part of the continent of Europe. After describing how most of Eastern Europe fell under the domination of foreign empires, and how this lead to a disparaging attitude towards its peoples and cultures, the author specifically details how Western authors of both general cultural histories and sporting histories and encyclopaedias have ignored Eastern Europe to a quite astonishing extent. The author then goes on to argue that Eastern Europe has a sporting tradition which is at least as rich, if not richer than that of the West. To illustrate this, the phenomena of medieval Polish horse racing, Bulgarian dry wrestling, Russian folk pugilism, Polish religious games, and Asian-influenced archery are explained in some detail. It is hoped that these examples will inspire sports historians from all parts of Europe to tap the rich resources of the East, and to treat this part of Europe as central rather than peripheral to European cultural history.     

“The process isn’t a case of report it and stop”: Athletes’ lived experience of whistleblowing on doping in sport

Whistleblowing is effective for exposing doping in sport, garnering increased support and promotion within the global anti-doping community. However, limited attention has been afforded towards understanding the doping whistleblowing process. In response, the authors convey a sense of the whistleblowing context by using the actual words of whistleblowers to illuminate their experience. To achieve this aim, the authors have adopted a narrative approach. Three doping whistleblowers were interviewed regarding their lived experiences of whistleblowing on doping and the data has been represented in the form of one composite creative non-fiction story. The story narrates the whistleblowing experience as a process whereby individuals must (a) determine what they witnessed and experienced was doping, (b) make the decision and take action to report it, and (c) deal with the myriad of consequences and emotions. It also highlights the dilemma faced by whistleblowers who are likely equally compelled to adhere to the moral of loyalty and fairness; yet in this context they are unable to do both. Stemming from the story presented and the forms of retribution experienced, the authors offer practical suggestions for sporting organisations to address in order to empower others to whistleblow on doping in sport. Specifically, organisations should establish and implement whistleblowing policies that: (a) provide protection for whistleblowers, (b) mandate whistleblowing education, and (c) identify an independent person for individuals to seek guidance and support from before, during and following the act of whistleblowing.     

‘A galaxy of sporting events’: sport’s role and significance in the Festival of Britain, 1951

The 1951 Festival of Britain has long been seen as a key moment in the country’s post-war history – especially in terms of popularising modern architecture and contemporary interior design, as well as symbolising the transition from acute economic austerity to a long period of relative affluence. However, successive writers have largely or completely ignored sport’s role in the Festival project. This paper argues that, in fact, sporting fixtures played an important role in the national and local festivities which were staged between May and September 1951. Their range, diversity and popularity means that the Festival should begin to be seen as a more successful and less insular event than previous studies have suggested. On the other hand, the support that such fixtures received from various newspapers and via the airwaves – courtesy of the BBC – indicates that the Festival faced far less media (and, indeed, political) opposition than its organisers liked to suggest and most historians have hitherto accepted. By studying the Festival’s sports programme, therefore, it is possible to gain fresh insights into the project as a whole and reassess its overall performance.