DOCSLIB.ORG

Virtual Thrower Versus Real Goalkeeper

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Virtual Thrower Versus Real Goalkeeper Nicolas Vignais* Virtual Thrower Versus Real M2S Laboratory, UFR APS, Rennes 2-ENS Cachan University, Goalkeeper: The Influence 35044 Rennes, France of Different Visual Conditions Richard Kulpa on Performance M2S Laboratory, UFR APS, Rennes 2-ENS Cachan University, 35044 Rennes, France and IRISA BUNRAKU Project, Abstract Campus de Beaulieu, 35042 Rennes, France In order to use virtual reality as a sport analysis tool, we need to be sure that an immersed athlete reacts realistically in a virtual environment. This has been validated Cathy Craig for a real handball goalkeeper facing a virtual thrower. However, we currently ignore School of Psychology, Queen’s which visual variables induce a realistic motor behavior of the immersed handball goal- University Belfast, Northern Ireland keeper. In this study, we used virtual reality to dissociate the visual information related to the movements of the player from the visual information related to the trajectory of Benoit Bideau the ball. Thus, the aim is to evaluate the relative influence of these different visual infor- M2S Laboratory, UFR APS, mation sources on the goalkeeper’s motor behavior. We tested 10 handball goalkeep- Rennes 2-ENS Cachan University, ers who had to predict the final position of the virtual ball in the goal when facing the 35044 Rennes, France following: only the throwing action of the attacking player (TA condition), only the resulting ball trajectory (BA condition), and both the throwing action of the attacking player and the resulting ball trajectory (TB condition). Here we show that performance was better in the BA and TB conditions, but contrary to expectations, performance was substantially worse in the TA condition. A significant effect of ball landing zone does, however, suggest that the relative importance between visual information from the player and the ball depends on the targeted zone in the goal. In some cases, body- based cues embedded in the throwing actions may have a minor influence on the ball trajectory and vice versa. Kinematics analysis was then combined with these results to determine why such differences occur depending on the ball landing zone and conse- quently how it can clarify the role of different sources of visual information on the motor behavior of an athlete immersed in a virtual environment. 1 Introduction Virtual reality is now being used as a tool to analyze and understand motor behavior in sport (Katz et al., 2006; Bideau et al., 2010). This promising technology has a number of advantages over video presentation or real-game situations. Firstly, all factors can be controlled and manipulated in a systematic manner, ensuring reproducibility between trials (Tarr & Warren, 2002). Sec- ondly, the effects of these modifications on the resulting behavior can be moni- tored in real time. Thirdly, the immersion of the subject in the virtual scene in an egocentric position allows the optical information gleaned from the virtual world to correspond directly to what the participant would see in a real sporting Presence, Vol. 19, No. 4, August 2010, 281–290 ª 2010 by the Massachusetts Institute of Technology *Correspondence to [email protected]. Vignais et al. 281 Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/PRES_a_00003 by guest on 27 September 2021 282 PRESENCE: VOLUME 19, NUMBER 4 situation (Cutting, 1997). Finally, the participant’s view- nent’s next move (Abernethy, Wood, & Parks, 1999). point is stereoscopic which has previously been high- While some studies have suggested that successful antici- lighted as an important factor when performing inter- pation is determined by the perception of spatial-tempo- ceptive tasks (Mazyn, Lenoir, Montagne, & Savelsbergh, ral information in the trajectory of the ball (Bastin, Craig, 2004). Given these advantages, this technology has been & Montagne, 2006; Craig et al., 2006; Lenoir, Musch, exploited to analyze and understand players’ perform- Thiery, & Savelsbergh, 2002; McLeod, Reed, & Dienes, ance in different sports such as soccer (Craig, Berton, 2006), others have shown that successful anticipatory Rao, Fernandez, & Bootsma, 2006), tennis (Molet behavior depends on the accurate perception of body- et al., 1999), handball (Bideau et al., 2004; Vignais based cues (Jackson, Warren, & Abernethy, 2006; Pan- et al., 2009), and rugby (Brault, Bideau, Kulpa, & Craig, chuk & Vickers, 2006; Savelsbergh, Williams, Van der 2009). Moreover this technology can be employed to Kamp, & Ward, 2002; Williams, Davids, Burwitz, & Wil- test team sport strategies (Metoyer & Hodgins, 2000) liams, 1994). The general consensus suggests that when or to train athletes in a simulator (Kelly & Hubbard, the temporal constraints are too tight (e.g., a penalty kick 2000). With respect to this latter option, Kelly and Hub- in soccer), players do not have enough time to act on ball bard have successfully designed a complete bobsled sim- trajectory information and consequently use body-based ulator which displays a graphical representation from the cues (Savelsbergh, Van der Kamp, Williams, & Ward, driver’s viewpoint on a cockpit-mounted monitor. 2005). In spite of this conclusion, the relative contribu- In spite of these advantages, using virtual reality as a tion of body-based versus ball flight information in per- sports analysis tool does raise new questions. One of the formance has not been properly tested. most important is the motor response of the athlete Here, we present body-based cues and ball trajectory immersed in a virtual environment. In fact, the motor information in isolation in order to better assess the rela- behavior of a subject can be considered as one of the tive importance of both types of visual information for physical measures of presence (Slater, 2009; Slater, performance. Using immersive interactive virtual reality, Khanna, Mortensen, & Yu, 2009). In sport, this concept this study allows dissociation between body-based cues has been used to validate a virtual sport situation. and ball flight information. The relative importance of Indeed, Bideau et al. (2003) compared the movement of these two visual elements in performance will be assessed handball goalkeepers during the interception of the same in order to understand why an athlete tends to respond throws made by real and virtual opponents. The results realistically to a virtual sport situation. To this end, we showed that the goalkeepers’ gestures in both environ- investigate the effects of different visual conditions of a ments were similar. Although we know that the virtual virtual throwing action on the performance of immersed sport situation used in this case study induced handball handball goalkeepers. goalkeepers to respond realistically, we do not yet know why they did. Are some visual elements displayed in the 2 Overview virtual scene more important than others to enable handball goalkeepers to react in a realistic way? In order to evaluate the influence of the different In most ball sports, successful anticipation of what an visual conditions of a throwing action on the handball opponent is going to do next can give a substantial com- goalkeepers’ performance, we developed a three-step petitive edge. The temporal constraints within which a process (see Figure 1). player must act are often very tight, and so early recogni- Step 1. First of all, to realistically animate the tion of an opponent’s actions or anticipation of where synthetic thrower and the ball in the virtual the ball is going can increase the player’s chances of environment, we captured real throwing making a successful counteracting move. Much of the actions. This led to the creation of a large research to date has focused on identifying the sources of motion database with throws to various visual information that players use to anticipate an oppo- places in the goal. Downloaded from http://www.mitpressjournals.org/doi/pdf/10.1162/PRES_a_00003 by guest on 27 September 2021 Vignais et al. 283 Figure 1. The three-step process includes data acquisition, real time experiment, and performance comparison. Step 2. Secondly, these captured throws were used segment, with six markers being reserved for the ball. by the MKM animation engine (Kulpa, Each player was asked to throw the ball 12 m from the Multon, & Arnaldi, 2005; Multon, Kulpa, goal, aiming for different prespecified target zones & Bideau, 2008) in order to realistically within the goal (no goalkeeper was present). For each animate the virtual character. The rendering of throw, the participant and ball movement were captured these animations was done with three different at 200 Hz using 12 infrared cameras. Nine trajectories visual conditions. that arrived close to the center of each zone were Step 3. Finally, the movements of the goalkeepers selected and used in the subsequent virtual animation were captured in real time. These data were part of the study (see Figure 2). then analyzed to determine which responses Kinematic throwing data, captured using the Vicon were successful. system, were then incorporated into the MKM (Manage- able Kinematic Motion) animation engine (Kulpa et al., 3 Motion Capture and Animation Process 2005; Multon et al., 2008) to animate the virtual hand- ball player in real time. Based on these captured motions, In order to animate the virtual character and the MKM can automatically synchronize, blend, and adapt ball, real handball throwing actions were recorded. actions to different morphologies and to external con- A Vicon motion capture system (Oxford Metrics, straints such as foot contacts. Virtual ball trajectories for Oxford, UK) was used to record movement kinematics the nine zones were calculated using another software from three top-level handball players. All the throwers module that incorporates data obtained from the motion were right-handed and had at least 10 years experience capture part of the study. Ball velocities were similar for playing handball in the top French league at the time of all nine trajectories (20 6 0.2 mÁsÀ1), making ball flight the study. Each player was equipped with 36 reflective time very nearly the same for all nine zones.
Load more

Recommended publications
  • Media Guide VELUX EHF Champions League Season 2012/2013 Group Phase
    Media Guide VELUX EHF Champions League Season 2012/2013 Group Phase Group B TABLE OF CONTENTS GROUP B – expert´s view 3 THW Kiel 4 BM Atlético de Madrid 7 MKB Veszprém KC 10 IK Sävehof 13 RK Celje Pivovarna Laško 16 HCM Constanta 19 Schedule of matches 22 2 TEAMS: 1. THW Kiel 2. MKB Veszprém KC 3. BM Atlético Madrid 4. IK Sävehof 5. Celje Pivovarna Laško 6. HCM Constanta Expert Francois-Xavier Houlet says: What a group this is! Kiel, Madrid (formerly known as Ciudad Real) and Celje have won seven of the last nine Champions League titles! Furthermore, Kiel and Madrid are last year#s finalists. And despite many changes in their respective rosters, both “giants” belong to the top favourites. Kiel’s main challenge is the integration of five new players into the team. Especially, new top- shooter Marko Vujin faces the very difficult task to follow the big footsteps that Kim Andersson left. Atlético Madrid had to cope with the departures of, among others, Dinart, Strbik, Chema or Abalo. But after having signed Barrachet, Gojun and Superstar Balić there is no doubt that Madrid will continue to be one of the top teams. Veszprém are for many people the dark horse that could surprise the favourites. With Ugalde, Chema Rodriguez or coach Ortega speaks, the Hungarian champion now plays with a Spanish accent. I believe, this bunch of players can go very far in the competition. Celje, Sävehof and Constanta will likely compete for fourth place in Group B. Celje and Constanta have signed some strong players and can rely on their home crowd support, which is why it will be difficult for Sävehof to repeat last season’s feat when they won the qualification tournament and then finished third place in the group.
    [Show full text]
  • Análise Da Performance Táctico-Técnica No Andebol De Alto Nível
    CORE Metadata, citation and similar papers at core.ac.uk Provided by Repositório Digital da Universidade da Madeira ANÁLISE DA PERFORMANCE TÁCTICO-TÉCNICA NO ANDEBOL DE ALTO NÍVEL Estudo das acções ofensivas com recurso à análise sequencial Dissertação apresentada com vista à obtenção do grau de Doutor em Educação Física e Desporto na especialidade de Ciências do Desporto Orientação: Professor Doutor Júlio Garganta da Silva Co-Orientação: Professora Doutora Maria Teresa Anguera Argilaga João Filipe Pereira Nunes Prudente 2006 Agradecimentos Dedicamos este espaço a todos aqueles que deram a sua contribuição para que esta dissertação fosse realizada. A todos eles queremos deixar aqui expresso o nosso sincero agradecimento: Ao Professor Doutor Júlio Garganta a forma como orientou este trabalho. Destacamos na sua orientação a qualidade e utilidade das suas intervenções, bem como a cordialidade e disponibilidade com que sempre nos recebeu e todo o apoio que disponibilizou. Destacamos também a liberdade de acção que nos permitiu, a qual foi um contributo importante para que este trabalho contribuísse para o nosso enriquecimento pessoal. À Professora Doutora Teresa Anguera ter aceitado a co-orientação. Com a sua competência, rigor, capacidade de trabalho e alegria contagiante contribuiu de forma decisiva para a realização desta dissertação. Um agradecimento especial a todos os que colaboraram no questionário realizado no âmbito deste estudo. Ao Departamento de Educação Física e Desporto da UMa, no nome do Professor Doutor Duarte Freitas, as condições proporcionadas, nomeadamente as que permitiram a dispensa de leccionação. A todos os colegas do Departamento que contribuíram para essa possibilidade o meu sincero agradecimento. Ao Professor Doutor Luís Sena Lino, pela forma amiga e disponível como sempre respondeu aos meus apelos e solicitações.
    [Show full text]
  • The Optimal Time of Day for Training During Ramadan: a Review Study Hamdi Chtourou1,2*, Omar Hammouda1,2, Asma Aloui1,3, Nizar Souissi1,4, Anis Chaouachi1
    The Optimal Time of Day for Training during Ramadan: A Review Study Hamdi Chtourou1,2*, Omar Hammouda1,2, Asma Aloui1,3, Nizar Souissi1,4, Anis Chaouachi1 1 Research Laboratory ''Sports performance optimization'' National Center of Medicine and Science in Sports (CNMSS), Tunis, Tunisia 2 High Institute of Sport and Physical Education, Sfax, Sfax University, Tunisia 3 High Institute of Sport and Physical Education, Gafsa, Gafsa University, Tunisia 4 High Institute of Sport and Physical Education, Ksar-Saïd, Manouba University, Tunisia A R T I C L E I N F O A B S T R A C T Article type: Literature concerning the effects of Ramadan fasting on sports performance presents Review article conflicting results. In this context, some studies reported a significant impairment of sports performance during the month of Ramadan. However, other studies suggested that Article History: Ramadan fasting has no significant effect on physical performance. Received: 07 March 2014 The discrepancies between the studies could be explained by time-of-day variations in Revised: 02 Apr 2014 testing. In this regard, recent studies reported that Ramadan negatively affects the Accepted: 09 Apr 2014 afternoon sports performance; however, the morning and the evening (after breaking the Published: 17 Apr 2014 fast) performances were not affected by fasting. This suggests that the optimal time of day for training during Ramadan is the morning or the evening. Therefore, coaches should Keywords: schedule the training sessions in the morning or evening during the month of Ramadan. Fast However, further studies should investigate the effect of training at a specific time of day Islam on sports performance during Ramadan.
    [Show full text]
  • Reading the Future from Body Movements – Anticipation in Handball
    This is a repository copy of Reading the future from body movements – anticipation in handball. White Rose Research Online URL for this paper: https://eprints.whiterose.ac.uk/163995/ Version: Accepted Version Article: Cocić, D., Vaci, N. orcid.org/0000-0002-8094-0902, Prieger, R. et al. (1 more author) (2020) Reading the future from body movements – anticipation in handball. Journal of Motor Behavior. ISSN 0022-2895 https://doi.org/10.1080/00222895.2020.1802216 This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Motor Behavior on 4th August 2020, available online: http://www.tandfonline.com/10.1080/00222895.2020.1802216 Reuse Items deposited in White Rose Research Online are protected by copyright, with all rights reserved unless indicated otherwise. They may be downloaded and/or printed for private study, or other acts as permitted by national copyright laws. The publisher or other rights holders may allow further reproduction and re-use of the full text version. This is indicated by the licence information on the White Rose Research Online record for the item. Takedown If you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing [email protected] including the URL of the record and the reason for the withdrawal request. [email protected] https://eprints.whiterose.ac.uk/ 1 Reading the Future from Body Movements – 2 Anticipation in Handball 3 4 Dijana Cocić1 Nemanja Vaci2 Robert Prieger3 Merim Bilalić1 5 6 7 8 9 1 University of Northumbria
    [Show full text]
  • A STUDY on the OPTIMAL DEFENSE POSITION of HANDBALL GOALKEEPER: FACING a FORWARD JUMP SHOT MADE from 9M Jonghyun Yangl, Chulsoo
    A STUDY ON THE OPTIMAL DEFENSE POSITION OF HANDBALL GOALKEEPER: FACING A FORWARD JUMP SHOT MADE FROM 9M Jonghyun Yangl, Chulsoo Chung2, lnsik Shin2 and Jaebum Park112 Institute of Sport science, Seoul National University, Seoul, Koreaq Department of Physlcal Education, Seoul Natlonal Unlverslty, Seoul, Korea2 The purpose of the study was to derive an optimal defense position for goalkeepers through calculating ideal defense area and actual defense area when blocking forward jump shots from 9 m distance. A total of 9 men's handball matches were captured with 4 digital video cameras from the 94m Korea National Sports Festival with consent from the Korea Handball Federation. Video clips with 78 forward jump shots from 9 m distance which included the whole movements of goalkeeper were analyzed. The ball's speed in the forward jump shot, release point of the ball, goalkeeper's defensive stance, and defensive position were analyzed. The actual defense position of goalkeeper was 1.10*0.37 m and the optimal defense position calculated through the movements of goalkeeper was 1.45 m from the goal line. KEY WORDS: goalkeeper, handball, optimal defense position. INTRODUCTION: In various sports, including handball, soccer, field hockey, ice hockey, lacrosse, and water polo, a player is designated as a goalkeeper, who is the rearmost defender in charge of preventing the opponent from scoring. Although each player who participates in a match plays an important role, unlike players in other position, a goalkeeper does not have any teammates in the backfield. In other words, a mistake by a field player can be overcome by the help of the other teammates, but a mistake by a goalkeeper directly leads to conceding a goal, which directly affects the outcome of the match.
    [Show full text]
  • Universidade Estadual Paulista “Júlio De Mesquita Filho” Faculdade De Ciências Bauru Departamento De Educação Física
    UNIVERSIDADE ESTADUAL PAULISTA “JÚLIO DE MESQUITA FILHO” FACULDADE DE CIÊNCIAS BAURU DEPARTAMENTO DE EDUCAÇÃO FÍSICA COMPREENDENDO O GOLEIRO NA INICIAÇÃO ESPORTIVA EM HANDEBOL LUCAS NASSUATO BAURU 2017 LUCAS NASSUATO COMPREENDENDO O GOLEIRO NA INICIAÇÃO ESPORTIVA EM HANDEBOL Orientadora: Prof.ª Dr.ª LILIAN APARECIDA FERREIRA Trabalho de Conclusão de Curso apresentado a Faculdade de Ciências da Universidade Estadual Paulista “Júlio de Mesquita Filho” - Câmpus de Bauru, para obtenção do grau de Bacharel em Educação Física BAURU 2017 AGRADECIMENTOS Antes de tudo, gostaria de agradecer a Deus por todas as oportunidades e por todas as pessoas que permaneceram ao meu lado ou mesmo aquelas que apenas estiveram de passagem durante uma das fases mais importantes da minha vida. Agradecer a dona Maria Elisa, que além de ser minha mãe é também o meu pai. As minhas irmãs Erika e Amanda, ao meu padrasto Jandir, a minha tia Silvana e a senhorinha de cabelos brancos, minha avó Tereza. Que são os verdadeiros motivos de eu nunca ter desistido. Agradecer a todos os meus amigos que sempre estiveram presentes e que nunca desistiram de mim. E também agradecer pelas amizades que foram construídas ao longo desses cinco anos de faculdade. Vocês têm o dom de transformar os dias mais comuns em momentos e lembranças inesquecíveis. Agradecer aos professores que tiveram as melhores intenções e que muito contribuíram para nossa formação profissional e também pessoal. E principalmente agradecer a professora Lílian, que sempre me incentivou e conseguiu reforçar ainda mais minha paixão pelo handebol. Agradecer pela oportunidade de vivenciar o papel de aluno e também de professor no projeto de extensão “Ensinando e Aprendendo Handebol”, no qual pude constatar a importância e os benefícios que a prática do esporte pode trazer na vida das pessoas.
    [Show full text]
  • Teap 2018 Abstracts
    60. TeaP 2018 Abstracts of the 60h Conference of Experimental Psychologists Edited by Alexander C. Schütz, Anna Schubö, Dominik Endres, Harald Lachnit March, 11th to 14th Marburg, Germany This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in other ways, and storage in data banks. The use of registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. The authors and the publisher of this volume have taken care that the information and recommendations contained herein are accurate and compatible with the standards generally accepted at the time of publication. Nevertheless, it is difficult to ensure that all the information given is entirely accurate for all circumstances. The publisher disclaims any liability, loss, or damage incurred as a consequence, directly or indirectly, of the use and application of any of the contents of this volume. © 2018 Pabst Science Publishers, 49525 Lengerich, Germany Printing: KM-Druck, 64823 Groß-Umstadt, Germany Contents Keynote lectures __________________________________________________________ 5 Contributions ___________________________________________________________ 11 Author index ___________________________________________________________ 307 Keynote lectures 5 Keynote lectures Control of Attention in Natural Environments Mary Hayhoe Center for Perceptual Systems, The University of Texas at Austin [email protected] In the context of natural behavior, humans must allocate attention and select information from the visual scene to satisfy behavioral goals.
    [Show full text]
  • Real Handball Goalkeeper Vs. Virtual Handball Thrower
    Benoit Bideau* Real Handball Goalkeeper vs. Richard Kulpa* Ste´ phane Me´ nardais† Virtual Handball Thrower Laetitia Fradet* Franck Multon*,† Paul Delamarche* Bruno Arnaldi*,† [email protected] Abstract *Laboratoire de Physiologie et de Biome´canique de l’Exercice Virtual reality offers new tools for human motion understanding. Several applications Musculaire, UFR-APS have been widely used in teleoperation, military training, driving and flying simula- Universite´ de Rennes 2 tors, and so forth. We propose to test if virtual reality is a valid training tool for the Av. Charles Tillon game of handball. We focused on the duel between a handball goalkeeper and a 35044 RENNES, FRANCE thrower. To this end, we defined a pilot experiment divided into two steps: an ex- periment with real subjects and another one with virtual throwers. The throwers’ †SIAMES project, IRISA motions were captured in order to animate their avatar in a reality center. In this Campus de Beaulieu paper, we focused on the evaluation of presence when a goalkeeper is confronting 35042 RENNES, FRANCE these avatars. To this end, we compared the goalkeeper’s gestures in the real and in the virtual experiment to determine if virtual reality engendered the same move- ments for the same throw. Our results show that gestures did not differ between the real and virtual environment. As a consequence, we can say that the virtual en- vironment offered enough realism to initiate natural gestures. Moreover, as in real games, we observed the goalkeeper’s anticipation to allow us to use virtual reality in future work as a way to understand the goalkeeper and thrower interactions.
    [Show full text]
  • The Handball Goalkeeper – Characteristics of the Position, Play, Techniques, Training
    #0# Central European Journal of Sport Sciences and Medicine | Vol. 32, No. 4/2020: 97–113 | DOI: 10.18276/cej.2020.4-10 THE HANDBALL GOALKEEPER – CHARACTERISTICS OF THE POSITION, PLAY, TECHNIQUES, TRAINING Adrian Struzik University of Szczecin, Faculty of Health and Physical Education, Poland Address for correspondence: Adrian Struzik University of Szczecin, Faculty of Health and Physical Education Al. Piastów 40B, 71-065 Szczecin, Poland Email: [email protected] Abstract Changes in a goalkeeper’s technique, his physical and mental preparation are ongoing, forced by the increasing power of the throw, speed of the game, improved players’ throwing capability; throws with rotation and other technical innovations involved in this element. The goalkeeper’s tasks are not only limited to defending the goal. He participates in launching a quick attack or quickly resuming play after conceding a goal. Goalkeeper training should be varied in order to mobilize the body’s full energy potential and shape the elements of the technique. The goalkeeper should be intelligent, courageous, endowed with the excellent physical condition and above all physically fit. Key words goalkeeper, handball, characteristics of the position, play, techniques, training Training Classification of physical exercise Training involves the nervous system and affects its performance. Because of the training stimulus, conduction is much faster, since it activates motor units. Movements (technique) become automated, acquired and therefore precise. Training – not only of
    [Show full text]
  • The Effect of Ramadan Intermittent Fasting on Dynamic Postural Control
    Biological Rhythm Research, 2014 Vol. 45, No. 1, 27–36, http://dx.doi.org/10.1080/09291016.2013.787759 The effect of Ramadan intermittent fasting on dynamic postural control in judo athletes Nafaa Souissia,e*, Amira Zouitaa, Hamdi Chtouroub,c, Hbiba Ferchichid, Catherine Dzirid, Salma Abedelmalekc and Nizar Souissib,c,d aBiomechanics Laboratory, National Institute of Orthopedics M.T. Kassab, Tunis, Tunisia; bResearch Laboratory, Sport Performance Optimisation, National Centre of Medicine and Sciences in Sport (CNMSS), Tunis, Tunisia; cResearch Unit (EM2S), High Institute of Sport and Physical Education, Sfax University, Sfax, Tunisia; dService of Medicine Physique- Fonctionnel Readaptation, Institut Kassab of Orthopedie, Manouba, Tunisia; eHigh Institute of Sport and Physical Education, Ksar-Saïd, Manouba University, Manouba, Tunisia The aim of this study was to evaluate Ramadan intermittent fasting (RIF) effects on dynamic postural control in male judo athletes. In a randomized order, 11 male judo- kas (22.5 ± 2.8 years, 173.8 ± 6.9 cm, and 70.3 ± 4.4 kg; mean ± SD) were asked to perform four protocols of dynamic postural control, i.e., sit to stand test (STS), step up and over test (SUO), step quick turn test (SQT), and forward lunge test (FL), one week before RIF (BRF), during the second week (SWR) of RIF, and three weeks after RIF (AR). The results of the present study showed that during the dynamic bal- ance tests, the movement time, lift-up index, and impact index during the STS test were significantly higher during SWR in comparison with BRF and AR (p < 0.05). However, those measured during the SUO test appeared independent of RIF.
    [Show full text]
  • Arxiv:1906.07132V1 [Cs.CL] 17 Jun 2019
    Avoiding Reasoning Shortcuts: Adversarial Evaluation, Training, and Model Development for Multi-Hop QA Yichen Jiang and Mohit Bansal UNC Chapel Hill fyichenj, [email protected] n o i Abstract t What was the father of Kasper Schmeichel s e voted to be by the IFFHS in 1992? u Multi-hop question answering requires a Q model to connect multiple pieces of evidence Kasper Peter Schmeichel (] ; born 5 November 1986) is a Danish professional footballer who plays as a scattered in a long context to answer the ques- g n i goalkeeper ... He is the son of former Manchester n s o tion. In this paper, we show that in the multi- c United and Danish international goalkeeper s o a e hop HotpotQA (Yang et al., 2018) dataset, D Peter Schmeichel. n i R a n h the examples often contain reasoning shortcuts e Peter Bolesław Schmeichel MBE (] ; born 18 C d l through which models can directly locate the o November 1963) is a Danish former professional answer by word-matching the question with a G footballer who played as a goalkeeper, and was voted sentence in the context. We demonstrate this the IFFHS World's Best Goalkeeper in 1992 and 1993. issue by constructing adversarial documents Edson Arantes do Nascimento (] ; born 23 October 1940), that create contradicting answers to the short- known as Pelé (] ), is a retired Brazilian professional footballer who played as a forward. In 1999, he was cut but do not affect the validity of the origi- r voted World Player of the Century by IFFHS.
    [Show full text]
  • Effectiveness of Male Handball Goalkeepers
    Effectiveness of Male Handball Goalkeepers: A historical overview 1982-2012 José J. Espina-Agulló, José A. Pérez-Turpin, José M. Jiménez-Olmedo, Alfonso Penichet-Tomás, Basilio Pueo Faculty of Education, University of Alicante, Ctra. San Vicente, s/n, 03550 Alicante, Spain Abstract: In this article, an analysis of the historical evolution of the effectiveness of goalkeepers in high level world competitions is carried out. To this end, 32 men's handball finals have been analyzed to record and classify effectiveness rates and goalkeeping actions in relation to opponent players’ throw areas and positions from 1982 to 2012. Analysis included throws from areas of 6, 7, 9 m and counterattack, performed from center or side positions. Results show no clear trend in effectiveness values registered throughout the time sample, both generally and specifically in terms of throwing position. The Kruskal-Wallis H test did not establish statistically significant differences (p>0.05) in goalkeeping effectiveness between any of the different analyzed periods, with a confidence interval of 95%. The findings of this study suggest that the ability of goalkeepers to prevent the goal from different throwing areas and positions has changed little over the past 30 years, although the game has incorporated more 1 offensive actions and therefore more attacks. This lack of progress can be attributed to that handball has not updated their game rules to make it faster and more spectacular. Key words: effectiveness, goalkeeping, handball, historical. 2 Effectiveness of Male Handball Goalkeepers: A historical overview 1982-2012 Abstract In this article, an analysis of the historical evolution of the effectiveness of goalkeepers in high level world competitions is carried out.
    [Show full text]