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Sample records for players ten players

  1. Veto players

    NARCIS (Netherlands)

    Warntjen, Andreas; Dowding, Keith

    2010-01-01

    Veto players are political actors whose consent is necessary to adopt a new policy. Put otherwise, they have veto power which allows them to prevent a change to the status quo. The concept is crucial to the influential veto player theory developed by George Tsebelis. Building on earlier work in form

  2. Veto players

    NARCIS (Netherlands)

    Warntjen, Andreas; Dowding, Keith

    2010-01-01

    Veto players are political actors whose consent is necessary to adopt a new policy. Put otherwise, they have veto power which allows them to prevent a change to the status quo. The concept is crucial to the influential veto player theory developed by George Tsebelis. Building on earlier work in form

  3. TEN DAYS TRAINING EFECTIVITY ON MEASURED SPECIFIC MOTOR ABILITIES OF BASKETBALL PLAYERS 15 YEARS OF AGE

    Directory of Open Access Journals (Sweden)

    Pavle Rubin

    2009-11-01

    Full Text Available Research took place in the basketball camp “Kikinda 07”. The sample consisted of 20 basketball players, 15 years of age (cadets, from Kikindas basketball clubs. On the inicial (9.VIII 2007. year and final (19.VIII 2007. year measurement, 9 tests spe- cific motor abilities (SMA were done: Player movement with the ball, Ball manipulation and Player movement without the ball. The aim was to prove 10 days training efektivity (15 trainings at 90 min. on specific motor abilities (SMA at cadets. Basketball players (cadets were trained under programme made by author of this research. The differences between two measurements (initial and final were proven using multivariate analysis of variance (MANOVA. Using this results the significant statistical difference appeared between two measuremeents (on .00 level. Univariate analysis of variance (ANOVA proved a statistical significant better results after training (in final measurement in 4 tests (variable: “Kamikaze” (shorted with driving (on .05 level; Driving the ball aro- und central circle (on .00 level (for SMA measurement movement player with a ball; and for SMA ball manipulation: Driblling with variations and Circling with ball around a body (on .00 level.

  4. The Player Engagement Process

    DEFF Research Database (Denmark)

    Schoenau-Fog, Henrik

    2011-01-01

    Engagement is an essential element of the player experience, and the concept is described in various ways in the literature. To gain a more detailed comprehension of this multifaceted concept, and in order to better understand what aspects can be used to evaluate engaging game play and to design...... engaging user experiences, this study investigates one dimension of player engagement by empirically identifying the components associated with the desire to continue playing. Based on a description of the characteristics of player engagement, a series of surveys were developed to discover the components......, categories and triggers involved in this process. By applying grounded theory to the analysis of the responses, a process-oriented player engagement framework was developed and four main components consisting of objectives, activities, accomplishments and affects as well as the corresponding categories...

  5. Active Learning for Player Modeling

    DEFF Research Database (Denmark)

    Shaker, Noor; Abou-Zleikha, Mohamed; Shaker, Mohammad

    2015-01-01

    Learning models of player behavior has been the focus of several studies. This work is motivated by better understanding of player behavior, a knowledge that can ultimately be employed to provide player-adapted or personalized content. In this paper, we propose the use of active learning for player...... experience modeling. We use a dataset from hundreds of players playing Infinite Mario Bros. as a case study and we employ the random forest method to learn mod- els of player experience through the active learning approach. The results obtained suggest that only part of the dataset (up to half the size...... of the full dataset) is necessary for the construction of accu- rate models that are as accurate as those constructed from the full dataset. This indicates the potential of the method and its benefits in cases when obtaining the data is expensive or time, storage or effort consuming. The results also indicate...

  6. Active Learning for Player Modeling

    DEFF Research Database (Denmark)

    Shaker, Noor; Abou-Zleikha, Mohamed; Shaker, Mohammad

    2015-01-01

    Learning models of player behavior has been the focus of several studies. This work is motivated by better understanding of player behavior, a knowledge that can ultimately be employed to provide player-adapted or personalized content. In this paper, we propose the use of active learning for player...... experience modeling. We use a dataset from hundreds of players playing Infinite Mario Bros. as a case study and we employ the random forest method to learn mod- els of player experience through the active learning approach. The results obtained suggest that only part of the dataset (up to half the size...... of the full dataset) is necessary for the construction of accu- rate models that are as accurate as those constructed from the full dataset. This indicates the potential of the method and its benefits in cases when obtaining the data is expensive or time, storage or effort consuming. The results also indicate...

  7. Multi-Player Quantum Games

    CERN Document Server

    Benjamin, S C; Benjamin, Simon C.; Hayden, Patrick M.

    2001-01-01

    Game theory is a mature field of applied mathematics. It formalizes the conflict between competing agents, and has found applications ranging from economics through to biology. Recently the first efforts have been made to introduce quantum information into game theory. For two-player games, it has been found that when the allowed `moves' are extended to include everything quantum mechanically possible, then the predominant strategies in the game can disappear, and only reappear if the players degrade the quantum coherence. Here we present the first study of quantum games with more than two players. We demonstrate that such games can exhibit `coherent' equilibrium strategies which have no analogue in classical games, or even in two-player quantum games. These equilibria are generally of a cooperative nature: quantum players can exploit their environment highly efficiently through the use of collaborative strategies.

  8. The Edubox Learning Design Player

    NARCIS (Netherlands)

    Tattersall, Colin; Vogten, Hubert; Hermans, Henry

    2005-01-01

    Tattersall, C., Vogten, H. & Hermans, H. (2005). The Edubox Learning Design Player. In: Koper, R. & Tattersall, C., Learning Design: A Handbook on Modelling and Delivering Networked Education and Training (pp. 303-310). Berlin-Heidelberg: Springer Verlag.

  9. The Astro Learning Design Player

    NARCIS (Netherlands)

    Sharples, Paul; Wilson, Scott; Popat, Kris; Griffiths, David; Beauvoir, Phillip

    2010-01-01

    Sharples, Paul Wilson, S., Popat, K., Griffiths, D., Beauvoir, P. (2009) The Astro Learning Design Player. This software is distributed under the three clause BSD license, copyright TENCompetence Foundation

  10. The Edubox Learning Design Player

    NARCIS (Netherlands)

    Tattersall, Colin; Vogten, Hubert; Hermans, Henry

    2005-01-01

    Tattersall, C., Vogten, H. & Hermans, H. (2005). The Edubox Learning Design Player. In: Koper, R. & Tattersall, C., Learning Design: A Handbook on Modelling and Delivering Networked Education and Training (pp. 303-310). Berlin-Heidelberg: Springer Verlag.

  11. Ten days of simulated live high:train low altitude training increases Hbmass in elite water polo players

    Science.gov (United States)

    Garvican-Lewis, Laura A; Clark, Sally A; Polglaze, Ted; McFadden, Greg; Gore, Christopher J

    2013-01-01

    Objectives Water polo requires high aerobic power to meet the demands of match play. Live high:train low (LHTL) may enhance aerobic capacity at sea level. Before the Olympics, the Australian women's water polo team utilised LHTL in an attempt to enhance aerobic fitness. Methods Over 6 months, 11 players completed three normobaric LHTL exposures (block 1:11 days at 3000 m; block 2+3:9 days at 2500 m, 11 days normoxia, 10 days at 2800 m). Haemoglobin mass (Hbmass) was measured through carbon monoxide-rebreathing. Before each block, the relationship between Hbmass and water polo-specific aerobic fitness was investigated using the Multistage Shuttle Swim Test (MSST). Effect size statistics were adopted with likely, highly likely and almost certainly results being >75%, >95%, >99%, respectively. A Pearson product moment correlation was used to characterise the association between pooled data of Hbmass and MSST. Results Hbmass (mean±SD, pre 721±66 g) likely increased after block 1 and almost certainly after block 2+3 (% change; 90% confidence limits: block 1: 3.7%; 1.3–6.2%, block 2+3: 4.5%; 3.8–5.1%) and the net effect was almost certainly higher after block 2+3 than before block 1 (pre) by 8.5%; 7.3–9.7%. There was a very large correlation between Hbmass (g/kg) and MSST score (r=0.73). Conclusions LHTL exposures of medal. PMID:24282211

  12. Frontal Lobe Function in Chess Players

    Directory of Open Access Journals (Sweden)

    Vahid Nejati

    2012-05-01

    Full Text Available Chess is considered as a cognitive game because of severe engagement of the mental resources during playing. The purpose of this study is evaluation of frontal lobe function of chess players with matched non-players. Wisconsin Card Sorting Test (WCST data showed no difference between the player and non-player groups in preservation error and completed categories but surprisingly showed significantly lower grade of the player group in correct response. Our data reveal that chess players dont have any preference in any stage of Stroop test. Chess players dont have any preference in selective attention, inhibition and executive cognitive function. Chess players' have lower shifting abilities than non-players.

  13. The Effectiveness Evaluation among Different Player-Matching Mechanisms in a Multi-Player Quiz Game

    Science.gov (United States)

    Tsai, Fu-Hsing

    2016-01-01

    This study aims to investigate whether different player-matching mechanisms in educational multi-player online games (MOGs) can affect students' learning performance, enjoyment perception and gaming behaviors. Based on the multi-player quiz game, TRIS-Q, developed by Tsai, Tsai and Lin (2015) using a free player-matching (FPM) mechanism, the same…

  14. The NBA’s Maximum Player Salary and the Distribution of Player Rents

    Directory of Open Access Journals (Sweden)

    Kelly M. Hastings

    2015-03-01

    Full Text Available The NBA’s 1999 Collective Bargaining Agreement (CBA included provisions capping individual player pay in addition to team payrolls. This study examines the effect the NBA’s maximum player salary on player rents by comparing player pay from the 1997–1998 and 2003–2004 seasons while controlling for player productivity and other factors related to player pay. The results indicate a large increase in the pay received by teams’ second highest and, to a lesser extent, third highest paid players. We interpret this result as evidence that the adoption of the maximum player salary shifted rents from stars to complementary players. We also show that the 1999 CBA’s rookie contract provisions reduced salaries of early career players.

  15. Adapting playware to multiple players

    DEFF Research Database (Denmark)

    Þorsteinsson, Arnar Tumi; Lund, Henrik Hautop; Mastorakis, Nikos

    2011-01-01

    With the creation of playware as intelligent hardware and software that creates play, it is possible to adapt the play tool to the individual user, and even to multiple users playing at the same time with the play tool. In this paper, we show how it is possible to implement adaptivity in modular...... to such differences, and argues that adaptivity is needed to make games fit to the individual users in both single-player games and multi-player games. As a case study, we implemented such adaptivity on modular interactive tiles for the single-user game ColorTimer, and for the multiple-user games PingPong, in which...

  16. Psychological games of entangled players

    CERN Document Server

    Zak, Michail

    2012-01-01

    The paper introduces a new approach to theory of differential games in which entangled players try to predict and influence actions of their adversaries. The entanglement is generated be a joint probability density known by the players. Incase of complex density, its imaginary part represents a measure of uncertainty of the density distribution. The novelty of the approach is in non-Newtonian mathematical formalism thatis based upon a behavioral model of Livings. The model is quantum-inspired: it represented by a modified Madelung equation which the quantum potential is replaced by different, specially chosen "computational" potential. It consists of motor dynamics simulating actual behavior of the object, and mental dynamics representing evolution of the corresponding knowledge-based and incorporating this knowledge in the for m of information flows into the motor dynamics. Due to feedback from mental dynamics, motor dynamics attains quantum-like properties: its trajectory splits into a family of different t...

  17. Two-Player Graph Pebbling

    Science.gov (United States)

    Prudente, Matthew James

    Given a graph G with pebbles on the vertices, we define a pebbling move as removing two pebbles from a vertex u, placing one pebble on a neighbor v, and discarding the other pebble, like a toll. The pebbling number pi( G) is the least number of pebbles needed so that every arrangement of pi(G) pebbles can place a pebble on any vertex through a sequence of pebbling moves. We introduce a new variation on graph pebbling called two-player pebbling. In this, players called the mover and the defender alternate moves, with the stipulation that the defender cannot reverse the previous move. The mover wins only if they can place a pebble on a specified vertex and the defender wins if the mover cannot. We define η(G), analogously, as the minimum number of pebbles such that given every configuration of the η( G) pebbles and every specified vertex r, the mover has a winning strategy. First, we will investigate upper bounds for η( G) on various classes of graphs and find a certain structure for which the defender has a winning strategy, no matter how many pebbles are in a configuration. Then, we characterize winning configurations for both players on a special class of diameter 2 graphs. Finally, we show winning configurations for the mover on paths using a recursive argument.

  18. Motivational profile quality players handball

    Directory of Open Access Journals (Sweden)

    Alfonso Martínez Moreno

    2017-06-01

    Full Text Available In the sport context, elite category, it is necessary to know all the factors, which in one way or another, affect the athletes throughout the different competitions. The object of study is to know the motivational profile of elite handball players. The sample consisted of 495 players, of whom 47.8% were boys and 52.2% girls, their ages ranged from 12 to 16 years, with an average of 13.8 years (dt = 1.0. Descriptive statistical analyzes of the sample, absolute and relative frequencies were performed for the qualitative variables and for the quantitative values minimum, maximum, mean, standard deviation, Cronbach's alpha. Correlation between variables, with the Pearson correlation coefficient. The MANCOVA test was performed to determine if there were differences between the dimensions of the questionnaire, according to age and years of practice. The results reveal that handball players elite category of the sample object of study have mainly intrinsic motivation, achieving high scores on general motivation, motivation achievement and motivation stimulation. In addition to moderately high values in introjected regulation and very low values in demotivation.

  19. [Dietary behaviours of volleyball and basketball players].

    Science.gov (United States)

    Szczepańska, Elzbieta; Spałkowska, Agnieszka

    2012-01-01

    In sports, such as basketball and volleyball, players must demonstrate the speed, strength, stamina and concentration. Correct nutrition affects the strength of the muscles and the extension of capacity. It is also necessary for the proper functioning of the nervous system and determines the rate of regeneration after physical effort. The aim of this study was to assess dietary behaviours of professional volleyball and basketball players and compare the prevalence of correct behaviours in both groups. 209 professional volleyball and basketball players from sports clubs localized in six Silesian cities were survived with the mean of author questionnaire. The chi-square test was used to examine differences in the prevalence of the correct behaviours among players. Analysis of the results obtained showed that 52% of the players had 4-5 meals a day. 35% of respondents had wholemeal bread and/or groats daily. Milk and dairy products daily ate 71% of surveyed players, meat and sausages 70% respectively. 41% of respondents had cottage cheese and 28% had fish several times a week. Vegetables and fruit were eaten by 21% and respectively 23% of respondents. Sweets were eaten daily by 40% of surveyed, while fast-food were eaten several times a week by 17% of players. Nutrients for athletes were used by 32%, and vitamin supplementation by 48% of respondents. Prevalence of correct dietary behaviour in the group of professional volleyball and basketball players differed. Basketball players statistically more frequently than volleyball players had 4-5 meals a day, had wholemeal bread and/or thick groats, milk and dairy products, meat and sausages, especially poultry. They had raw vegetables and fruit several times a day. They drank more than 2.5 liters of fluids per day. They also significantly more frequently than volleyball players consumed the fast-food occasionally or never. Dietary behaviours of surveyed players were incorrect. Comparison of prevalence of proper behaviours

  20. Vitamin D Deficiency Among Professional Basketball Players.

    Science.gov (United States)

    Fishman, Matthew P; Lombardo, Stephen J; Kharrazi, F Daniel

    2016-07-01

    Vitamin D plays an important role in several systems of the human body. Various studies have linked vitamin D deficiency to stress and insufficiency fractures, muscle recovery and function, and athletic performance. The prevalence of vitamin D deficiency in the elite athletic population has not been extensively studied, and very few reports exist among professional athletes. There is a high prevalence of vitamin D deficiency or insufficiency among players attending the National Basketball Association (NBA) Combine. Cross-sectional study; Level of evidence, 3. This is a retrospective review of data previously collected as part of the routine medical evaluation of players in the NBA Combines from 2009 through 2013. Player parameters evaluated were height, weight, body mass index (BMI), and vitamin D level. Statistical analysis using t tests and analysis of variance was used to detect any correlation between the player parameters and vitamin D level. Vitamin D levels were categorized as deficient (32 ng/mL). After institutional review board approval was submitted to the NBA, the NBA released deidentified data on 279 players who participated in the combines from 2009 through 2013. There were 90 players (32.3%) who were deficient, 131 players (47.0%) who were insufficient, and 58 players (20.8%) who were sufficient. A total of 221 players (79.3%) were either vitamin D deficient or insufficient. Among all players included, the average vitamin D level was 25.6 ± 10.2 ng/mL. Among the players who were deficient, insufficient, and sufficient, the average vitamin D levels were 16.1 ± 2.1 ng/mL, 25.0 ± 3.4 ng/mL, and 41.6 ± 8.6 ng/mL, respectively. Player height and weight were significantly increased in vitamin D-sufficient players compared with players who were not sufficient (P = .0008 and .009, respectively). Player age and BMI did not significantly differ depending on vitamin D status (P = .15 and .77, respectively). There is a high prevalence of vitamin D deficiency

  1. Player-character dynamics in multi-player Role Playing Games

    DEFF Research Database (Denmark)

    Tychsen, Anders; McIlwain, Doris; Brolund, Thea

    2007-01-01

    This paper presents the results of a comprehensive empirical study of the impact of integrating complex game characters in multi-player Role Playing Games across tabletop and digital formats. Players were provided with characters that had detailed background history, personality and goals. Player...... and player engagement with their character and no correlation between enjoyment and similarity between player and character personality. © 2007 Authors & Digital Games Research Association (DiGRA)....... and character personality were assessed using the Extended Personal Attributes Questionnaire (EPAQ) and further questionnaires administered to measure player enjoyment and the player-character relationship. Results include a high level of player enjoyment across all formats, a high correlation between enjoyment...

  2. An investigation of player to player character identification via personal pronouns

    DEFF Research Database (Denmark)

    Hichens, Michael; Drachen, Anders; Richards, Deborah

    2012-01-01

    The player character is an important feature of many games, where it is through the character that the player interacts with game world. There has been considerable interest in the relationship between the player and the player character. Much of this work has examined the identification of players...... in playing video games, did have a statistically significant affect, indicating that different levels of identification are more dependent on the player than on the game. This indicates that players are not a homogeneous group with respect to player character identification and is an important consideration...... with their characters, generally taking either a textual analysis approach, or has been empirical work that has explicitly identified the idea of identification through survey instruments, etc. The work presented here takes a different empirical approach, focusing on the use of various pronoun forms (first, second...

  3. PSYCHOLOGICAL AND TACTICAL PREPA RATION OF JUNIOR TENNIS PLAYERS

    Directory of Open Access Journals (Sweden)

    Saša Milenković

    2007-05-01

    Full Text Available Ta king in to con si de ra tion the physi cal in vol ve ment, psychological stabi lity and tactical competence of a player in con tem po rary pro fes si o nal ten nis, it can be con cluded that ten nis players are con stantly ex po sed to ma king stre nu o us ef forts. More over, ta king in to ac co unt the system and the or ga ni za tion of to ur na ments, which in vol ve regu lar trips and thus chan ging ti me zo nes, types of the gro unds at ten nis co urts, clo sed sports halls and open ten nis to ur na ments, we can lo gi cally con clu de that psycho lo gi cal and tac ti cal pre pa ra tion of players in lo wer cat he go ri es is of gre at im por tan ce. The pro blem of this study re fers to the cho i ce of tasks gi ven to a player. Tasks are di rectly aimed at psycho lo gi cal sta bi lity which players ha ve to de ve lop be fo re the match, in the warm up pe riod and du ring the match it self. Tac ti cal com pe ten ce is of vi tal im por tan ce for each ten nis player who lo oks forward to ac hi e ving high sports re sults. In that sen se, a the o re ti cal ap pro ach to a tac tic is ne e ded, as well as a partial analysis of tac ti cal va ri a bles adаpted to players and to con di ti ons at matches.

  4. Serious eye injury in badminton players.

    Science.gov (United States)

    Kelly, S P

    1987-10-01

    Serious eye injury can occur in badminton players and may become more frequent. The causes and nature of such injuries in this sport in six patients are discussed. All were playing competitive doubles matches. Penetrating eye injury due to a shattered glass spectacle lens occurred. Players should be advised not to wear spectacles with glass lenses. Ocular protection in this sport is desirable, and the forward player should hold the racket in front of the face.

  5. The Prevalence of Injuries in Professional Turkish Soccer Players

    Science.gov (United States)

    Yamaner, Faruk; Gumusdag, Hayrettin; Kartal, Alparslan; Gumus, M.; Gullu, A.; Imamoglu, O.

    2011-01-01

    Study aim: To assess the prevalence and anatomical sites of injuries in professional soccer players in one game season. Material and methods: A cohort of 510 professional male soccer players consisting of 48 goalkeepers, 194 defence players, 189 mid-field players and 79 forward players of the 1st and 2nd Turkish Professional Soccer Leagues in…

  6. Chess players' fame versus their merit

    CERN Document Server

    Simkin, M V

    2015-01-01

    We investigate a pool of international chess title holders born between 1901 and 1943. Using Elo ratings we compute for every player his expected score in a game with a randomly selected player from the pool. We use this figure as player's merit. We measure players' fame as the number of Google hits. The correlation between fame and merit is 0.38. At the same time the correlation between the logarithm of fame and merit is 0.61. This suggests that fame grows exponentially with merit.

  7. Physiological characteristics of international female soccer players.

    Science.gov (United States)

    Manson, Sarah A; Brughelli, Matt; Harris, Nigel K

    2014-02-01

    The purpose of this study was to investigate the physiological characteristics of Fédération Internationale de Football Association (FIFA) eligible international female soccer players aged 14-36 years and to determine if measures were significantly different for players selected (i.e., starters) to the starting line up for an FIFA tournament as compared with those not selected (i.e., nonstarters). Fifty-one (N = 18 Under 17; N = 18 Under 20; N = 15 Senior) international female soccer players participated in this study. The subjects underwent measurements of anthropometry (height and body mass), lower body strength (isokinetic testing), sprint kinetics and kinematics (nonmotorized treadmill), leg power (unilateral jumping), and maximal aerobic velocity (30:15 intermittent fitness test) during the final preparatory stage for an FIFA event. Outcomes of the age group data indicate that differences in physiological capacities are evident for the Under 17 players as compared with those for the Under 20 and Senior capped international players, suggesting a plateau in the acquisition of physical qualities as players mature. Starters tended to be faster (effect size [ES] = 0.55-1.0, p velocity (ES = 0.78-2.45, p velocity (ES = 0.87, p players, where maximal aerobic velocity was the primary difference between starters and nonstarters (ES = 0.83-2.45, p players. Coaches should emphasize the development of speed, maximal aerobic velocity, and leg strength in developing female soccer players.

  8. Cooperation: New Players in Africa

    Directory of Open Access Journals (Sweden)

    Philippe Hugon

    2010-03-01

    Full Text Available In the context of globalisation and the current global financial crisis, new players are emerging in cooperation in Africa. These partners loosen financial constraints and conditionalities, increase the room for manoeuvre and stimulate commodity markets. On the other hand, they also increase the risks of renewed indebtedness and potentially weaken the coordination of aid policies. Do these partnerships call the new cooperation practices of OECD countries into question? Do they justify the return to a realpolitik or are they repeating the earlier mistakes of industrial powers? Can these mistakes be corrected? The question also arises as to whether the global crisis, which has a profound effect on Africa, will lead to a withdrawal or to a passing of the baton on to new, emerging powers. This article highlights the new geopolitical issues concerning Africa in a multipolar world, then discusses the new players involved in cooperation in Africa, before going on to explore the horizons that are opening up for cooperation in Africa, in particular with regard to the global crisis.

  9. The potential risk of personal stereo players

    DEFF Research Database (Denmark)

    Hammershøi, Dorte; Ordoñez, Rodrigo Pizarro; Reuter, Karen

    2010-01-01

    The technological development within personal stereo systems, such as MP3 players, e. g. iPods, has changed music listening habits from home entertainment to everyday and everywhere use. The technology has developed considerably, since the introduction of cassette players and CD walkmen. High...

  10. The potential risk of personal stereo players

    DEFF Research Database (Denmark)

    Hammershøi, Dorte; Ordoñez, Rodrigo Pizarro; Reuter, Karen

    2010-01-01

    The technological development within personal stereo systems,such as MP3 players, e. g. iPods, has changed music listening habits from home entertainment to everyday and everywhere use. The technology has developed considerably, since the introduction of cassette players and CD walkmen. High...

  11. Who Are the Players in Canadian Curriculum?

    Science.gov (United States)

    Milburn, Geoffrey

    1987-01-01

    Labels range of persons advocating different theoretical positions of Canadian curriculum as "players." Describes players as "managers,""predictors,""transformers,""sleuths,""analysts." Values varied viewpoints for attention to language regarding curriculum, critical review of ideas/concepts, examination of current policies, awareness of history…

  12. QuizUp Single Player Web

    OpenAIRE

    Gunnar Marteinsson 1983; Kristinn Júlíusson 1993; Sonja Jónsdóttir 1992; Steinar Þór Árnason 1993

    2016-01-01

    In this report we discuss the B.Sc. project named QuizUp Single Player Web. The project was developed at Reykjavik University in the spring of 2016 in collaboration with Plain Vanilla Games, the makers of the world famous QuizUp app. We developed a Single Player Web application based on the original multiplayer game.

  13. Inferring Player Experiences Using Facial Expressions Analysis

    NARCIS (Netherlands)

    Tan, C.T.; Bakkes, S.; Pisan, Y.; Blackmore, K.; Nesbitt, K.; Smith, S.P.

    2014-01-01

    Understanding player experiences is central to game design. Video captures of players is a common practice for obtaining rich reviewable data for analysing these experiences. However, not enough has been done in investigating ways of preprocessing the video for a more efficient analysis process. Thi

  14. Finite stage asymmetric repeated games: Both players' viewpoints

    KAUST Repository

    Li, Lichun

    2017-01-05

    In asymmetric zero-sum games, one player has superior information about the game over the other. It is known that the informed players (maximizer) face the tradeoff of exploiting its superior information at the cost of revealing its superior information, but the basic point of the uninformed player (minimizer)\\'s decision making remains unknown. This paper studies the finite stage asymmetric repeated games from both players\\' viewpoints, and derives that not only security strategies but also the opponents\\' corresponding best responses depends only on the informed player\\'s history action sequences. Moreover, efficient LP formulations to compute both player\\'s security strategies are provided.

  15. Injuries in racket sports among Slovenian players.

    Science.gov (United States)

    Kondric, Miran; Matković, Branka R; Furjan-Mandić, Gordana; Hadzić, Vedran; Dervisević, Edvin

    2011-06-01

    On the sample of 83 top Slovenian athletes we have studied the frequency of injuries among table tennis, tennis and badminton players, types of injuries and severity of injuries--the latter based on data of players absences from training and/or competition processes. The most liable parts to injuries are shoulder girdle (17.27%), spine (16.55%) and ankle (15.83%), while foot (10.07%) and wrist (12.23%) are slightly less liable to injuries. The most frequent injuries in racket sports pertain to muscle tissues. According to this data, the majority of injuries occur halfway through a training session or a competition event, mostly during a competition season. The injuries primarily pertain to muscle tissues; these are followed by joint and tendon injuries. There are no differences between male and female players. Compared to other racket sports players, table tennis players suffer from fewer injuries.

  16. Decreased Nerve Conduction Velocity in Football Players

    Directory of Open Access Journals (Sweden)

    Daryoush Didehdar

    2014-06-01

    Full Text Available Background: Lower limbs nerves are exposed to mechanical injuries in the football players and the purpose of this study is to evaluate the influence of football on the lower leg nerves. Materials and Methods: Nerve conduction studies were done on 35 male college students (20 football players, 15 non active during 2006 to 2007 in the Shiraz rehabilitation faculty. Standard nerve conduction techniques using to evaluate dominant and non dominant lower limb nerves. Results: The motor latency of deep peroneal and tibial nerves of dominant leg of football players and sensory latency of superficial peroneal, tibial and compound nerve action potential of tibial nerve of both leg in football players were significantly prolonged (p<0.05. Motor and sensory nerve conduction velocity of tibial and common peroneal in football players were significant delayed (p<0.05. Conclusion: It is concluded that football is sport with high contact and it causes sub-clinical neuropathies due to nerve entrapment.

  17. Outcomes of microfracture in professional basketball players.

    Science.gov (United States)

    Cerynik, Douglas L; Lewullis, Gabriel E; Joves, Brian C; Palmer, Michael P; Tom, James A

    2009-09-01

    Surgical treatment for chondral defects of the knee in competitive running and jumping athletes remains controversial. This study evaluated the performance outcomes of professional basketball players in the National Basketball Association (NBA) who underwent microfracture. Data from 24 professional basketball players from 1997 to 2006 was obtained and analyzed. NBA player efficiency ratings (PER) were calculated for two seasons before and after injury. A control group of 24 players was used for comparison. Study group and control group demographics including age, NBA experience, and minutes per game demonstrated no statistical difference. Mean time to return to an NBA game was 30.0 weeks from the time of surgery. The first season after returning to competition PER and minutes per game decreased by 3.5 (P 0.05) and 3.0 min (P NBA game. On return to competition player performance and minutes per game are diminished.

  18. Executive functioning in highly talented soccer players.

    Science.gov (United States)

    Verburgh, Lot; Scherder, Erik J A; van Lange, Paul A M; Oosterlaan, Jaap

    2014-01-01

    Executive functions might be important for successful performance in sports, particularly in team sports requiring quick anticipation and adaptation to continuously changing situations in the field. The executive functions motor inhibition, attention and visuospatial working memory were examined in highly talented soccer players. Eighty-four highly talented youth soccer players (mean age 11.9), and forty-two age-matched amateur soccer players (mean age 11.8) in the age range 8 to 16 years performed a Stop Signal task (motor inhibition), the Attention Network Test (alerting, orienting, and executive attention) and a visuospatial working memory task. The highly talented soccer players followed the talent development program of the youth academy of a professional soccer club and played at the highest national soccer competition for their age. The amateur soccer players played at a regular soccer club in the same geographical region as the highly talented soccer players and play in a regular regional soccer competition. Group differences were tested using analyses of variance. The highly talented group showed superior motor inhibition as measured by stop signal reaction time (SSRT) on the Stop Signal task and a larger alerting effect on the Attention Network Test, indicating an enhanced ability to attain and maintain an alert state. No group differences were found for orienting and executive attention and visuospatial working memory. A logistic regression model with group (highly talented or amateur) as dependent variable and executive function measures that significantly distinguished between groups as predictors showed that these measures differentiated highly talented soccer players from amateur soccer players with 89% accuracy. Highly talented youth soccer players outperform youth amateur players on suppressing ongoing motor responses and on the ability to attain and maintain an alert state; both may be essential for success in soccer.

  19. Incidence of Stingers in Young Rugby Players.

    Science.gov (United States)

    Kawasaki, Takayuki; Ota, Chihiro; Yoneda, Takeshi; Maki, Nobukazu; Urayama, Shingo; Nagao, Masashi; Nagayama, Masataka; Kaketa, Takefumi; Takazawa, Yuji; Kaneko, Kazuo

    2015-11-01

    A stinger is a type of neurapraxia of the cervical roots or brachial plexus and represents a reversible peripheral nerve injury. The incidence of and major risk factors for stingers among young rugby players remain uninvestigated. To investigate the incidence, symptoms, and intrinsic risk factors for stingers in elite rugby union teams of young players. Descriptive epidemiology study. A total of 569 male rugby players, including 358 players from 7 high school teams and 211 players from 2 university teams, were investigated using self-administered preseason and postseason questionnaires. The prevalence of a history of stingers was 33.9% (95% CI, 30.3-37.9), and 20.9% (119/569) of players experienced at least 1 episode of a stinger during the season (34.2 [95% CI, 26.2-42.1] events per 1000 player-hours of match exposure). The reinjury rate for stingers per season was 37.3% (95% CI, 30.4-44.2). Using the multivariate Poisson regression method, a history of stingers in the previous season and the grade and position of the player were found to be risk factors for stingers during the current season. The mean severity of injury was 2.9 days, with 79.3% (191/241) of the players not losing any time from playing after sustaining a stinger injury and 5.8% (14/241) of the players recovering within more than 14 days. The most frequent symptom was numbness in the unilateral upper extremity, and the most severe symptom was weakness of grasping (mean severity, 6 days). A logistic regression analysis indicated that a history of stingers in the previous season and an injury with more than 3 symptoms, especially motor weakness, were correlated with the severity of injury. Young rugby players with a history of stingers have a significantly high rate of repeat injuries. Although nearly 80% of the players experienced only minimal (0-1 day) time loss injuries, neurological deficits sometimes last beyond 1 month. A history of stingers was identified to be the strongest risk factor for

  20. Examining Player Anger in World of Warcraft

    Science.gov (United States)

    Barnett, Jane; Coulson, Mark; Foreman, Nigel

    This questionnaire study of the sources of anger in World of Warcraft applies classical quantitative measurement scale construction to a new problem, generating a host of questionnaire items that could find use in future studies, and identifying four major categories of events that cause negative effect among players. First, 33 players provided examples of in-game scenarios that had made them angry, and their responses were culled to create a 93-item battery rated by hundreds of player respondents in terms of anger intensity and anger frequency. An iterative process of factor analysis and scale reliability assessment led to a 28-item instrument measuring four anger-provoking factors: Raids/Instances, Griefers, Perceived Time Wasting, and Anti-social Players. These anger-causing scenarios were then illustrated by concrete examples from player and researcher experiences in World of Warcraft. One striking finding is that players become angry at other players' negative behavior, regardless of whether that behavior was intended to harm.

  1. Applied physiology of female soccer players.

    Science.gov (United States)

    Davis, J A; Brewer, J

    1993-09-01

    Women's soccer is in its infancy as a sport and research into its physiological demands and the physical characteristics of players is somewhat limited. There is now an increasing demand for scientific investigation of the female game and of the players, match analysis and role variations requiring particular attention. Current research suggests that the demands of the game for women are similar to those placed on male players. Women are reported to cover a similar distance (mean 8471m) to their male counterparts during a game and much the same proportions of the game appear to be devoted to exercise of varying intensities. Furthermore, female and male players appear to tax the aerobic and anaerobic energy systems to a similar level. The physical and physiological characteristics of female soccer players are comparable with those of other female games players and are more favourable than average for the population. Mean body fat percentages of between 19.7 and 22.0% and VO2max values of between 47.1 and 57.6 ml/kg/min have been reported for elite female players, while faster than average sprint times are also characteristic of them.

  2. Computing Decoupled Residuals for Compact Disc Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Andersen, Palle

    2006-01-01

    In order to improve Compact Disc Players playability regarding playing Compact Discs with surface faults, like scratches and fingerprints etc, the attention has been put on fault tolerant control schemes. Almost every of those methods are based on fault detection. The standard approach is to use...... a pair of residuals generated by Compact Disc Player. However, these residuals depend on the performance of position servos in the Compact Disc Player. In other publications of the same authors a pair of decoupled residuals is derived. However, the computation of these alternative residuals has been...

  3. Towards Player-Driven Procedural Content Generation

    DEFF Research Database (Denmark)

    Shaker, Noor; Yannakakis, Georgios N.; Togelius, Julian

    2012-01-01

    Generating immersive game content is one of the ultimate goals for a game designer. This goal can be achieved by realizing the fact that players’ perception of the same game differ according to a number of factors including: players’ personality, playing styles, expertise and culture background....... While one player might find the game immersive, others may quit playing as a result of encountering a seemingly insoluble problem. One promising avenue towards optimizing the gameplay experience for individual game players is to tailor player experience in real-time via automatic game content generation......-driven content generation....

  4. High School Football Players Use Their Helmets to Tackle Other Players Despite Knowing the Risks

    Science.gov (United States)

    Kuriyama, Andrew M; Nakatsuka, Austin S

    2017-01-01

    There is greater attention to head-related injuries and concussions in American football. The helmet's structural safety and the way that football players use their helmets are important in preventing head injuries. Current strategies include penalizing players for high-risk behavior such as leading with their helmet or hitting an opposing player above the shoulder. Passive strategies include helmet modification to better protect the head of the players or to change the playing style of the players. Hawai‘i high school varsity football players were surveyed to determine how they use their helmets and how a new helmet design would affect their style of play. One hundred seventy-seven surveys were completed; 79% said that they used their helmet to hit an opposing player during a tackle and 46% said they made this contact intentionally. When asked about modifying helmets with a soft material on the outside, 48% said they thought putting a soft cover over a regular helmet would protect their head better. However, many participants said that putting a soft cover over their regular helmet was a bad idea for various reasons. Most young football players use their helmets to block or tackle despite being taught they would be penalized or potentially injured if they did so. By gaining a better understanding of why and how players use their helmets and how they would respond to new helmet designs, steps can be taken to reduce head injuries for all levels of play.

  5. Technical player profiles related to the physical fitness of young female volleyball players predict team performance.

    Science.gov (United States)

    Dávila-Romero, C; Hernández-Mocholí, M A; García-Hermoso, A

    2015-03-01

    This study is divided into three sequential stages: identification of fitness and game performance profiles (individual player performance), an assessment of the relationship between these profiles, and an assessment of the relationship between individual player profiles and team performance during play (in championship performance). The overall study sample comprised 525 (19 teams) female volleyball players aged 12-16 years and a subsample (N.=43) used to examine study aims one and two was selected from overall sample. Anthropometric, fitness and individual player performance (actual game) data were collected in the subsample. These data were analyzed through clustering methods, ANOVA and independence chi-square test. Then, we investigated whether the proportion of players with the highest individual player performance profile might predict a team's results in the championship. Cluster analysis identified three volleyball fitness profiles (high, medium, and low) and two individual player performance profiles (high and low). The results showed a relationship between both types of profile (fitness and individual player performance). Then, linear regression revealed a moderate relationship between the number of players with a high volleyball fitness profile and a team's results in the championship (R2=0.23). The current study findings may enable coaches and trainers to manage training programs more efficiently in order to obtain tailor-made training, identify volleyball-specific physical fitness training requirements and reach better results during competitions.

  6. The Cheerleader and the Football Player.

    Science.gov (United States)

    Patil, Malati

    2001-01-01

    Describes an activity in physics using a narrative about a bet between a cheerleader who claims she can lift a 300-pound football player off the ground. Includes questions, teaching notes, and solutions. (MM)

  7. Menstrual cycle disorders in female volleyball players.

    Science.gov (United States)

    Wodarska, M; Witkoś, J; Drosdzol-Cop, A; Dąbrowska, J; Dąbrowska-Galas, M; Hartman, M; Plinta, R; Skrzypulec-Plinta, V

    2013-07-01

    The aim of this study was to examine the relation between increased physical activity and menstrual disorders in adolescent female volleyball players. The study was conducted on 210 Polish female volleyball players, aged 13-17 years, the authorship questionnaire was used. The results of the study showed that irregular menstruation occurred in 19% of girls, spotting between menstrual periods in 27% and heavy menstruation was reported in 33% of girls. Out of all volleyball female players participating in the study, 94 girls (45%) declared absence of menstrual periods after regular cycles. Statistical analysis showed that the more training hours per week, the bigger probability of the occurrence of irregular menstruation. It was concluded that the number of hours of volleyball training per week affects regularity of menstrual cycles in female volleyball players. The absence of menstruation might be caused by the duration of training per week or years of training.

  8. Towards Generic Models of Player Experience

    DEFF Research Database (Denmark)

    Shaker, Noor; Shaker, Mohammad; Abou-Zleikha, Mohamed

    2015-01-01

    further examine whether generic features of player be- haviour can be defined and used to boost the modelling per- formance. The accuracies obtained in both experiments in- dicate a promise for the proposed approach and suggest that game-independent player experience models can be built.......-dependent and their applicability is usually limited to the system and the data used for model construction. Establishing models of user experience that are highly scalable while maintaing the performance constitutes an important research direction. In this paper, we propose generic models of user experience in the computer games...... domain. We employ two datasets collected from players in- teractions with two games from different genres where accu- rate models of players experience were previously built. We take the approach one step further by investigating the mod- elling mechanism ability to generalise over the two datasets. We...

  9. Video Player Keyboard Shortcuts: MedlinePlus

    Science.gov (United States)

    ... page: https://medlineplus.gov/hotkeys.html Video Player Keyboard Shortcuts To use the sharing features on this ... enable JavaScript. MedlinePlus offers a set of accessible keyboard shortcuts for our latest Health videos on the ...

  10. Scouting the Elite, Unbreakable Football Player.

    Science.gov (United States)

    Moore, M

    1981-02-01

    Some NFL football teams see physiological profiling as a means to protect and enhance their competitive and business success. Whether football players will benefit by increased performance and fewer injuries remains to be seen.

  11. Tales of the Unexpected: Coping among Female Collegiate Volleyball Players

    Science.gov (United States)

    Holt, Nicholas L.; Berg, Kylie-Joy; Tamminen, Katherine A.

    2007-01-01

    The purpose of this study was to examine patterns of appraisal, coping, and coping effectiveness in sport. Ten players from a collegiate female volleyball team were interviewed on two occasions, first in the week before a provincial final playoff tournament and in the week following the tournament. Data were transcribed verbatim and subjected to…

  12. Tales of the Unexpected: Coping among Female Collegiate Volleyball Players

    Science.gov (United States)

    Holt, Nicholas L.; Berg, Kylie-Joy; Tamminen, Katherine A.

    2007-01-01

    The purpose of this study was to examine patterns of appraisal, coping, and coping effectiveness in sport. Ten players from a collegiate female volleyball team were interviewed on two occasions, first in the week before a provincial final playoff tournament and in the week following the tournament. Data were transcribed verbatim and subjected to…

  13. Does the Quantum Player Always Win the Classical One?

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hai-Jun; FANG Xi-Ming

    2004-01-01

    @@ We study quantum games in which the players have different strategic spaces. We find that the player who can use a quantum strategic space does not always possess more payoffs than the player who is restricted to apply only classical strategies. We find the condition of the classical player getting more payoffs than the quantum player. We also find that the game exhibits intriguing structures.

  14. RETIRED MATCHES AMONG MALE PROFESSIONAL TENNIS PLAYERS

    Directory of Open Access Journals (Sweden)

    Kristijan Breznik

    2012-06-01

    Full Text Available The aim of this study was to explore the effect of characteristics of various games and players on the proportion of retired tennis matches in the Open Era of tennis. The data included over 420,000 matches played among 17,553 tennis players in the period from 1968 to the end of 2010. The influence of the surface type was clearly confirmed, with the proportion of retired matches being higher on hard and clay courts compared to grass and carpet surfaces. Similarly, more retired matches were observed in outdoor venues than in indoor ones. The impact of other variables, tournament types, rounds at which the game was played and both players' ranks, is more ambiguous. Our interpretation of the obtained results is presented in the paper. Network analytic methods were applied to extract players with the most retired matches in their careers. Eventually, we defined a group of top tennis players and gave a more precise insight into retired matches in that group. Correspondence analysis was used to visually display the two-mode network of top players and the proportion of retired matches by surface type

  15. Cortical thinning in former professional soccer players.

    Science.gov (United States)

    Koerte, Inga K; Mayinger, Michael; Muehlmann, Marc; Kaufmann, David; Lin, Alexander P; Steffinger, Denise; Fisch, Barbara; Rauchmann, Boris-Stephan; Immler, Stefanie; Karch, Susanne; Heinen, Florian R; Ertl-Wagner, Birgit; Reiser, Maximilian; Stern, Robert A; Zafonte, Ross; Shenton, Martha E

    2016-09-01

    Soccer is the most popular sport in the world. Soccer players are at high risk for repetitive subconcussive head impact when heading the ball. Whether this leads to long-term alterations of the brain's structure associated with cognitive decline remains unknown. The aim of this study was to evaluate cortical thickness in former professional soccer players using high-resolution structural MR imaging. Fifteen former male professional soccer players (mean age 49.3 [SD 5.1] years) underwent high-resolution structural 3 T MR imaging, as well as cognitive testing. Fifteen male, age-matched former professional non-contact sport athletes (mean age 49.6 [SD 6.4] years) served as controls. Group analyses of cortical thickness were performed using voxel-based statistics. Soccer players demonstrated greater cortical thinning with increasing age compared to controls in the right inferolateral-parietal, temporal, and occipital cortex. Cortical thinning was associated with lower cognitive performance as well as with estimated exposure to repetitive subconcussive head impact. Neurocognitive evaluation revealed decreased memory performance in the soccer players compared to controls. The association of cortical thinning and decreased cognitive performance, as well as exposure to repetitive subconcussive head impact, further supports the hypothesis that repetitive subconcussive head impact may play a role in early cognitive decline in soccer players. Future studies are needed to elucidate the time course of changes in cortical thickness as well as their association with impaired cognitive function and possible underlying neurodegenerative process.

  16. Epidemiology of musculoskeletal injury in the tennis player.

    Science.gov (United States)

    Abrams, Geoffrey D; Renstrom, Per A; Safran, Marc R

    2012-06-01

    Tennis is a popular sport with tens of millions of players participating worldwide. This popularity was one factor leading to the reappearance of tennis as a medal sport at the 1988 Summer Olympics in Seoul, South Korea. The volume of play, combined with the physical demands of the sports, can lead to injuries of the musculoskeletal system. Overall, injury incidence and prevalence in tennis has been reported in a number of investigations. The sport creates specific demands on the musculoskeletal system, with acute injuries, such as ankle sprains, being more frequent in the lower extremity while chronic overuse injuries, such as lateral epicondylitis, are more common in the upper extremity in the recreational player and shoulder pain more common in the high-level player. This review discusses the epidemiology of injuries frequently experienced in tennis players and examines some of these injuries' correlation with the development of osteoarthritis. In addition, player-specific factors, such as age, sex, volume of play, skill level, racquet properties and grip positions as well as the effect of playing surface on the incidence and prevalence of injury is reported. Finally, recommendations on standardisation of future epidemiological studies on tennis injuries are made in order to be able to more easily compare results of future investigations.

  17. Morphology of young handball players

    Directory of Open Access Journals (Sweden)

    Adair da Silva Lopes

    2007-06-01

    Full Text Available The purpose of this study was to compare anthropometric and body composition variables from the best male handball athletes competing in the Santa Catarina state youth competition to variables from the other athletes in the same competition, by game position. Seven of the twelve coaches participating in the Santa Catarina Open Youth Games 2004 (up to 18 years freely consented to select the seven best athletes in the competition (one goalkeeper, one pivot, two wingers and three backcourt players. In addition to these seven players, there were a further 79 team members taking part, bringing the total sample size to 86 athletes. The following variables were analyzed: body weight (MC, height (ES, arm span (ENV, hand breadth (DPA, wrist breadth (DRU, forearm circumference (PA, percentage fat (%G, fat mass (MG and lean body mass (MCM. Descriptive statistics (means and standard deviations were employed to classify the athletes according to court position. The chosen athletes were compared with the others using the single-sample t test (p RESUMO Este estudo objetivou comparar variáveis antropométricas e da composição corporal dos melhores atletas de uma competição juvenil (até 18 anos de handebol masculino de Santa Catarina, em relação aos demais atletas da competição por posição de jogo. Sete dentre os doze técnicos participantes dos Joguinhos Abertos de Santa Catarina 2004 aceitaram, voluntariamente, realizar a escolha da seleção dos sete melhores atletas da competição (um goleiro, um pivô, dois extremas e três armadores. Contabilizou-se, além dos sete atletas da seleção, mais 79 atletas titulares de suas equipes, totalizando na amostra, 86 atletas. Foram analisadas as variáveis: massa corporal (MC, estatura (ES, percentual de gordura (%G, massa de gordura (MG, massa corporal magra (MCM, envergadura (ENV, diâmetro palmar (DPA, diâmetro biestilóide rádio-ulnar (DRU e perímetro do antebraço (PA. Utilizou-se a estat

  18. Sports injuries in Plus League volleyball players.

    Science.gov (United States)

    Cieśla, E; Dutkiewicz, R; Mgłosiek, M; Nowak-Starz, G; Markowska, M; Jasiński, P; Dudek, J

    2015-06-01

    Although physical activity brings a range of lifelong health benefits, it may also lead to injuries that pose a significant threat to health. It is particularly noticeable in people involved in professional sports where sport-related injuries commonly occur and are associated with intense exercise which aims to improve physical fitness. The article attempts to determine incidence of sports injuries reported by Plus League volleyball players, as well as to identify their most common types and causes. The research project involved 90 Plus League volleyball players aged 18-37 with the average age of 25.11 (SD±5.378). A method of diagnostic survey was applied to collect empirical data by means of questionnaire developed by the authors (researchers). The results were statistically analysed and verified with the analysis of variance (ANOVA) and χ2 test at the significance level (or critical P-value) of P≤0.05. Over 87% of the respondents suffered from at least one sport-related injury. In total, 362 injuries occurred, on average 4.02 injuries per one volleyball player. The most common sports injuries involved ankle or talocrural joint (46 injuries), knee and lower leg muscles (30), interphalangeal articulations of fingers (30) as well as shoulder joint. More than half of the injuries (57%) occurred twice or three times. Volleyball players commonly sustain injuries through contact with an opposing player in competition. Sport-specific injuries may also occur due to exhaustion, lack of rest and undertreated injuries. The most common volleyball-related injuries are primarily talocrural joint, hand and shoulder injuries. Common types of injuries that can affect volleyball players include muscles, joints and ligaments injuries, sprains and strains as well as bruises. Most of these injuries are caused by exhaustion, contact with an opposing player during competition and fatigue. The incidence of sport-related injuries seems to be influenced by such factors as somatic

  19. Influence of Glove Type on Mobility Performance for Wheelchair Rugby Players

    NARCIS (Netherlands)

    Mason, Barry S.; van der Woude, L. H. V.; Goosey-Tolfrey, V. L.

    2009-01-01

    Objective: The purpose of this study was to determine the effectiveness of different glove types on mobility performance in a series of field tests specific to wheelchair rugby. Design: Ten international wheelchair rugby players performed three drills in each glove condition: (i) players' current gl

  20. Influence of Glove Type on Mobility Performance for Wheelchair Rugby Players

    NARCIS (Netherlands)

    Mason, Barry S.; van der Woude, L. H. V.; Goosey-Tolfrey, V. L.

    Objective: The purpose of this study was to determine the effectiveness of different glove types on mobility performance in a series of field tests specific to wheelchair rugby. Design: Ten international wheelchair rugby players performed three drills in each glove condition: (i) players' current

  1. Do media players cause interference with pacemakers?

    Science.gov (United States)

    Thaker, Jay P; Patel, Mehul B; Shah, Ashok J; Liepa, Valdis V; Brunett, Joseph D; Jongnarangsin, Krit; Gardiner, Joseph C; Thakur, Ranjan

    2009-11-01

    Electrical devices generate electromagnetic fields that may interfere with pacemakers. Media players cause telemetry interference with pacemakers, but it is not known whether they cause direct interference with pacemakers. The purpose of this study was to examine the interaction between pacemakers and 3 different media players. In this prospective, randomized study, 54 patients with dual chamber pacemakers who were in sinus rhythm underwent baseline observation, followed by observation under telemetry communication. These patients were then randomly evaluated with 3 media players (iPod 3G, iPod Photo, and iPod Touch Apple, Cupertino, CA) with and without telemetry communication for 1 minute each. Patients were monitored for pacemaker malfunction using a single-channel ECG during exposure to media players. The pacemaker was interrogated after each exposure and an interrogation report was printed for evaluation. Pacemaker interference was categorized as type I, II, or III. Types I and II interference described telemetry interference and type III interference was defined as any direct interference with pacemaker function or programmed parameters. A total of 54 patients (29 men and 25 women; mean age 77.2 +/- 9.3 y) were evaluated. In total, of the 162 tests (for telemetry interference) 36.4% were positive (Type I and II). Type III interference was also evaluated in 162 tests and none showed any evidence of direct interference. Media players cause telemetry interference with pacemakers, but they do not directly interfere with pacemaker function.

  2. Game Performance Evaluation in Male Goalball Players

    Directory of Open Access Journals (Sweden)

    Molik Bartosz

    2015-12-01

    Full Text Available Goalball is a Paralympic sport exclusively for athletes who are visually impaired and blind. The aims of this study were twofold: to describe game performance of elite male goalball players based upon the degree of visual impairment, and to determine if game performance was related to anthropometric characteristics of elite male goalball players. The study sample consisted of 44 male goalball athletes. A total of 38 games were recorded during the Summer Paralympic Games in London 2012. Observations were reported using the Game Efficiency Sheet for Goalball. Additional anthropometric measurements included body mass (kg, body height (cm, the arm span (cm and length of the body in the defensive position (cm. The results differentiating both groups showed that the players with total blindness obtained higher means than the players with visual impairment for game indicators such as the sum of defense (p = 0.03 and the sum of good defense (p = 0.04. The players with visual impairment obtained higher results than those with total blindness for attack efficiency (p = 0.04, the sum of penalty defenses (p = 0.01, and fouls (p = 0.01. The study showed that athletes with blindness demonstrated higher game performance in defence. However, athletes with visual impairment presented higher efficiency in offensive actions. The analyses confirmed that body mass, body height, the arm span and length of the body in the defensive position did not differentiate players’ performance at the elite level.

  3. Comparison of two aerobic field tests in young tennis players.

    Science.gov (United States)

    Fargeas-Gluck, Marie-Agnès; Léger, Luc A

    2012-11-01

    This study compares the maximal responses of a new aerobic tennis field test, the NAVTEN to a known aerobic field test, often used with young tennis players, that is, the continuous multistage 20-m shuttle run test (20-m SRT). The NAVTEN is an intermittent (1-minute/1-minute) multistage test with side-to-side displacements and ball hitting. Ten young elite tennis players aged 12.9 ± 0.3 (mean ± SD) randomly performed both tests and were continuously monitored for heart rate (HR) and oxygen uptake (V[Combining Dot Above]O2) using the Vmax ST (Sensormedics). The 20-m SRT and NAVTEN show similar HRpeak (202 ± 6.1 vs. 208 ± 9.5, respectively) and V[Combining Dot Above]O2peak (54.2 ± 5.9 vs. 54.9 ± 6.0 ml·kg·min). Pearson correlations between both tests were 0.88 and 0.92 for V[Combining Dot Above]O2peak and maximal speed, respectively. The NAVTEN yielded V[Combining Dot Above]O2peak values that are typical for active subjects of that age and are similar to the 20-m SRT supporting its use to measure aerobic fitness of young tennis players in specific and entertaining field conditions. The fact that two-thirds of the tennis players achieved a different ranking (±1 rank) with the NAVTEN and the 20-m SRT suggests that the NAVTEN may be more specific than the 20-m SRT to assess aerobic fitness of tennis players. From a practical point of view, the NAVTEN test is more specific and pedagogical for young tennis players even though both tests yield similar maximal values.

  4. Motivation and Sport Injuries in Handball Players

    Directory of Open Access Journals (Sweden)

    Laguna, María

    2010-12-01

    Full Text Available The aim of the study was to test whether different levels of motivation are related to the injuries suffered by elite athletes. The sample consists of 80 professional handball players of ASOBAL League, with a mean age of 24.83 years (+ 5.21. Motivation was assessed through the CPRD scale (Gimeno, Buceta & Pérez-Llantada; 1999 and a self-report questionnaire was used to register sports injuries. The results indicate that there is a relationship between motivational levels and the risk for injury. Specifically, players with high motivated players had a greater number of moderate injuries. Although it may seem paradoxical, it is possible that an excessively high motivation leads to overachievement and risk behaviors, which in turn facilitate the appearance of lesions.

  5. Cricket club looking for new players

    CERN Multimedia

    Cricket Club

    2016-01-01

    The CERN Cricket Club, having lost several key players, has had a very difficult season so far and is desperately in need of new players. Having qualified for the Cricket Switzerland semi-finals for the last two years (unfortunately losing both), this year we are bottom of the Western Pool, having played the last two league matches with only 10 players. If you are interested in playing cricket please join us at net practice, which takes place on the Prevessin site each Thursday evening from 18:00 to around 20:00 (weather permitting) or send me an e-mail (see below). Please have a look at the Cricket Club web site for more information: http://cern.ch/Club-Cricket/ Chris Onions, President of the CERN Cricket Club   (christopher.onions@gmail.com)

  6. Big Data for Business Ecosystem Players

    Directory of Open Access Journals (Sweden)

    Perko Igor

    2016-06-01

    Full Text Available In the provided research, some of the Big Data most prospective usage domains connect with distinguished player groups found in the business ecosystem. Literature analysis is used to identify the state of the art of Big Data related research in the major domains of its use-namely, individual marketing, health treatment, work opportunities, financial services, and security enforcement. System theory was used to identify business ecosystem major player types disrupted by Big Data: individuals, small and mid-sized enterprises, large organizations, information providers, and regulators. Relationships between the domains and players were explained through new Big Data opportunities and threats and by players’ responsive strategies. System dynamics was used to visualize relationships in the provided model.

  7. Adapting virtual camera behaviour through player modelling

    DEFF Research Database (Denmark)

    Burelli, Paolo; Yannakakis, Georgios N.

    2015-01-01

    Research in virtual camera control has focused primarily on finding methods to allow designers to place cameras effectively and efficiently in dynamic and unpredictable environments, and to generate complex and dynamic plans for cinematography in virtual environments. In this article, we propose...... a novel approach to virtual camera control, which builds upon camera control and player modelling to provide the user with an adaptive point-of-view. To achieve this goal, we propose a methodology to model the player’s preferences on virtual camera movements and we employ the resulting models to tailor...... the viewpoint movements to the player type and her game-play style. Ultimately, the methodology is applied to a 3D platform game and is evaluated through a controlled experiment; the results suggest that the resulting adaptive cinematographic experience is favoured by some player types and it can generate...

  8. Mean Field Games with a Dominating Player

    Energy Technology Data Exchange (ETDEWEB)

    Bensoussan, A., E-mail: axb046100@utdallas.edu [The University of Texas at Dallas, International Center for Decision and Risk Analysis, Jindal School of Management (United States); Chau, M. H. M., E-mail: michaelchaumanho@gmail.com; Yam, S. C. P., E-mail: scpyam@sta.cuhk.edu.hk [The Chinese University of Hong Kong, Department of Statistics (Hong Kong, People’s Republic of China) (China)

    2016-08-15

    In this article, we consider mean field games between a dominating player and a group of representative agents, each of which acts similarly and also interacts with each other through a mean field term being substantially influenced by the dominating player. We first provide the general theory and discuss the necessary condition for the optimal controls and equilibrium condition by adopting adjoint equation approach. We then present a special case in the context of linear-quadratic framework, in which a necessary and sufficient condition can be asserted by stochastic maximum principle; we finally establish the sufficient condition that guarantees the unique existence of the equilibrium control. The proof of the convergence result of finite player game to mean field counterpart is provided in Appendix.

  9. There is no game without a player

    DEFF Research Database (Denmark)

    Larsen, Lasse Juel

    on the subject matter from the catalogue of game theory. All four suggestions exclude the player from the relationship. This paper introduces a phenomenological point of view and includes the player in order to understand the relationship between structure and dressing. It argues that players constitute a bridge......This paper is a search for meaning or to be more precise a study of how meaning is produced between ontology and fiction in computer games. It sets out to investigate the relationship between formal abstract game structures and game representation (dressing) by presenting four suggestions...... or the center which establishes, upholds and renegotiate the relationship between formal game structure and game dressing. It also argues that players’ interaction with both structure and dressing produce meaning and the production of meaning is the relationship between formal abstract game structures and game...

  10. Modelling Virtual Camera Behaviour Through Player Gaze

    DEFF Research Database (Denmark)

    Picardi, Andrea; Burelli, Paolo; Yannakakis, Georgios N.

    2012-01-01

    In a three-dimensional virtual environment, aspects such as narrative and interaction largely depend on the placement and animation of the virtual camera. Therefore, virtual camera control plays a critical role in player experience and, thereby, in the overall quality of a computer game. Both game...... industry and game AI research focus on the devel- opment of increasingly sophisticated systems to automate the control of the virtual camera integrating artificial intel- ligence algorithms within physical simulations. However, in both industry and academia little research has been carried out...... on the relationship between virtual camera, game-play and player behaviour. We run a game user experiment to shed some light on this relationship and identify relevant dif- ferences between camera behaviours through different game sessions, playing behaviours and player gaze patterns. Re- sults show that users can...

  11. Individual recovery profiles in basketball players.

    Science.gov (United States)

    Moreno, Jordi; Ramos-Castro, Juan; Rodas, Gil; Tarragó, Joan R; Capdevila, Lluís

    2015-01-01

    In the sport context, recovery has been characterized as a multifactor process (physiological, psychological, behavioral, social, etc.). This study takes a multidisciplinary approach to find psychophysiological markers of the stress-recovery process. It aims to determine how athletes' specific recovery actions relate to their perceptions of recovery, and Heart Rate Variability (HRV). A total of 196 assessments were analyzed from 6 players on a men's professional basketball team within the Liga LEB Oro basketball federation (2012/2013 season). Perceptions of recovery, recovery strategies, and HRV were recorded. The results show a pattern of individual differences in behavior related to athletes' recovery actions and HRV profiles throughout the season (p < .05). Moreover, we observed that each player had different recovery needs. In light of these results, we suggest an individualistic approach to evaluating and monitoring recovery to attend more accurately to each player's recovery needs.

  12. Cervical joint position sense in rugby players versus non-rugby players.

    Science.gov (United States)

    Pinsault, Nicolas; Anxionnaz, Marion; Vuillerme, Nicolas

    2010-05-01

    To determine whether cervical joint position sense is modified by intensive rugby practice. A group-comparison study. University Medical Bioengineering Laboratory. Twenty young elite rugby players (10 forwards and 10 backs) and 10 young non-rugby elite sports players. Participants were asked to perform the cervicocephalic relocation test (CRT) to the neutral head position (NHP) that is, to reposition their head on their trunk, as accurately as possible, after full active left and right cervical rotation. Rugby players were asked to perform the CRT to NHP before and after a training session. Absolute and variable errors were used to assess accuracy and consistency of the repositioning for the three groups of Forwards, Backs and Non-rugby players, respectively. The 2 groups of Forwards and Backs exhibited higher absolute and variable errors than the group of Non-rugby players. No difference was found between the two groups of Forwards and Backs and no difference was found between Before and After the training session. The cervical joint position sense of young elite rugby players is altered compared to that of non-rugby players. Furthermore, Forwards and Backs demonstrated comparable repositioning errors before and after a specific training session, suggesting that cervical proprioceptive alteration is mainly due to tackling and not the scrum.

  13. Injury incidence and balance in rugby players.

    Science.gov (United States)

    M, Jaco Ras; Puckree, Threethambal

    2014-01-01

    Objective : This study determined and correlated injury incidence and balance in rugby players. A prospective survey with balance testing was conducted on first year rugby academy players (N= 114). Injury incidence, static and dynamic balance were tested pre and post-season using a Biosway portable balance system. The data was analysed using paired and independent samples t-tests at pscrum-half (14.80%) playing position, injuries in the 2nd half of the match (57%), and during contact (67%). Conclusion : Injury incidence was related to static and dynamic balance in forward right direction only.

  14. Fault Predictive Control of Compact Disk Players

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Wickerhauser, Mladen Victor

    2006-01-01

    Optical disc players such as CD-players have problems playing certain discs with surface faults like scratches and fingerprints. The problem is to be found in the servo controller which positions the optical pick-up, such that the laser beam is focused on the information track. A scheme handling ...... of the feature based control scheme, such that a prediction step is included. The proposed scheme is compared with the feature based control scheme, in the perspective of handling surface faults, by simulations. These simulations show the improvements given by the proposed algorithm....

  15. Sprint, agility, strength and endurance capacity in wheelchair basketball players

    National Research Council Canada - National Science Library

    Yanci, J; Granados, C; Otero, M; Badiola, A; Olasagasti, J; Bidaurrazaga-Letona, I; Iturricastillo, A; Gil, Sm

    ...; and secondly, to analyse the physical characteristics measured by sprint, agility, strength and endurance field tests in wheelchair basketball (WB) players. 16 WB players (33.06 ± 7.36 years, 71.89...

  16. Jet Lag a Drag on Pro Baseball Players

    Science.gov (United States)

    ... 163187.html Jet Lag a Drag on Pro Baseball Players Study found traveling across time zones linked ... might be more than just tiring for pro baseball players: The resulting jet lag may actually harm ...

  17. The development of a test of repeated-sprint ability for elite women's soccer players.

    Science.gov (United States)

    Gabbett, Tim J

    2010-05-01

    The purpose of this study was to develop a game-specific test of repeated-sprint ability for elite women's soccer players. Nineteen elite women's soccer players (mean +/- SD; age, 18.1 +/- 2.9 y) participated in this study. After familiarization, players completed a repeated-sprint test consisting of 6 x 20-m maximal effort sprints, on a 15-second cycle. At the completion of each sprint, players performed a 10-m deceleration and a 10-m active jog recovery. Ten elite female soccer players performed the test on 2 occasions, 1 week apart, to determine the reliability of the test. In addition, the validity of the repeated-sprint test to discriminate among players of different playing ability was evaluated by testing national (n = 11) and state (n = 8) women's soccer players. Heart rate and blood lactate concentration were recorded to determine the physiological responses to the test. The total sprint time proved to be highly reproducible (intraclass correlation coefficient = 0.91; typical error of measurement = 1.5%). However, the percentage decrement was less reliable (intraclass correlation coefficient = 0.14, typical error of measurement = 19.5%). The repeated-sprint test was valid in discriminating between national- and state-level players, with national players having significantly lower (p repeated-sprint times than state players (20.9 +/- 0.5 s vs. 23.3 +/- 0.4 s). The mean (+/-SD) heart rate and blood lactate concentration were 182 +/- 6 beats/min and 9.3 +/- 2.0 mmol/L, respectively. The results of this study demonstrate that the developed repeated-sprint test discriminates players of higher and lesser skill levels and offers a reliable method of assessing repeated-sprint ability in elite women's soccer players when results are expressed as the total sprint time.

  18. Training Patterns of Wheelchair Basketball Players in Turkey

    Science.gov (United States)

    Tatar, Yasar

    2008-01-01

    The aim of this study was to analyze technical drills, warm-up and cool-down exercises used by wheelchair basketball players of the Turkish league in relation to training sessions. 33 male wheelchair basketball players participated in the study (mean age 26.6[plus or minus]5,95 years). All players reported that they used warm-up exercises before…

  19. Automatic player detection and identification for sports entertainment applications

    NARCIS (Netherlands)

    Mahmood, Zahid; Ali, Tauseef; Khattak, Shadid; Hasan, Laiq; Khan, Samee U.

    2014-01-01

    In this paper, we develop an augmented reality sports broadcasting application for automatic detection, recognition of players during play, followed by display of personal information of players. The proposed application can be divided into four major steps. In first step, each player in the image i

  20. Synthetic Players: A Quest for Artificial Intelligence in Computer Games

    Directory of Open Access Journals (Sweden)

    Jouni Smed

    2005-03-01

    Full Text Available Synthetic players are the computer-controlled actors in a computer game. In this paper, we describe both the implementation issues and the behavioural expectations related to synthetic players. We recognize the role of synthetic players by analysing the components of games in general and computer games in particular.

  1. Assessment of Cardiovascular Risk in Collegiate Football Players and Nonathletes

    Science.gov (United States)

    Dobrosielski, Devon A.; Rosenbaum, Daryl; Wooster, Benjamin M.; Merrill, Michael; Swanson, John; Moore, J. Brian; Brubaker, Peter H.

    2010-01-01

    Collegiate American football players may be at risk for cardiovascular disease. Objective: To compare cardiovascular disease risk factors and cardiovascular structure and function parameters of football players, stratified by position, to a group of sedentary, nonathletes. Participants: Twenty-six collegiate football players and 13 nonathletes…

  2. Assessment of Cardiovascular Risk in Collegiate Football Players and Nonathletes

    Science.gov (United States)

    Dobrosielski, Devon A.; Rosenbaum, Daryl; Wooster, Benjamin M.; Merrill, Michael; Swanson, John; Moore, J. Brian; Brubaker, Peter H.

    2010-01-01

    Collegiate American football players may be at risk for cardiovascular disease. Objective: To compare cardiovascular disease risk factors and cardiovascular structure and function parameters of football players, stratified by position, to a group of sedentary, nonathletes. Participants: Twenty-six collegiate football players and 13 nonathletes…

  3. Understanding the Mismatch Between Coaches' and Players' Perceptions of Exertion

    NARCIS (Netherlands)

    Brink, Michel S.; Kersten, Anna W.; Frencken, Wouter G. P.

    2017-01-01

    A mismatch between the training exertion intended by a coach and the exertion perceived by players is well established in sports. However, it is unknown whether coaches can accurately observe exertion of individual players during training. Furthermore, the discrepancy in coaches' and players' percep

  4. High School Rugby Players' Perception of Coaching Effectiveness

    Science.gov (United States)

    Broodryk, Retief; van den Berg, Pieter Hendrick

    2011-01-01

    The aims of this study were firstly to determine the players' perceptions of their respective coaches' coaching effectiveness and secondly, determine the difference between big and small schools of the players' perceptions of their respective coaches' coaching effectiveness. Four hundred and seventy six players from 22 schools were asked to fill…

  5. Preferred Leadership Behaviours of Male and Female Badminton Players

    OpenAIRE

    Rajkumar S HARMA

    2015-01-01

    Pr eferences for specific coaching behaviours of male and female Badminton players were measured by the modified and revised Leadership Scale for Sport. Eighty two (Males=61, Females=21) badminton players were selected from amongst the players representing th eir respective university teams in East - zone Inter - university Badminton (Men/Women) tournaments held at Bilaspur (CG). The present investigation noted ...

  6. Automatic player detection and identification for sports entertainment applications

    NARCIS (Netherlands)

    Mahmood, Zahid; Ali, Tauseef; Khattak, Shadid; Hasan, Laiq; Khan, Samee U.

    In this paper, we develop an augmented reality sports broadcasting application for automatic detection, recognition of players during play, followed by display of personal information of players. The proposed application can be divided into four major steps. In first step, each player in the image

  7. Dynamic Difficulty Balancing for Cautious Players and Risk Takers

    Directory of Open Access Journals (Sweden)

    Guy Hawkins

    2012-01-01

    Full Text Available Dynamic balancing of game difficulty can help cater for different levels of ability in players. However, performance in some game tasks depends on not only the player's ability but also their desire to take risk. Taking or avoiding risk can offer players its own reward in a game situation. Furthermore, a game designer may want to adjust the mechanics differently for a risky, high ability player, as opposed to a risky, low ability player. In this work, we describe a novel modelling technique known as particle filtering which can be used to model various levels of player ability while also considering the player's risk profile. We demonstrate this technique by developing a game challenge where players are required to make a decision between a number of possible alternatives where only a single alternative is correct. Risky players respond faster but with more likelihood of failure. Cautious players wait longer for more evidence, increasing their likelihood of success, but at the expense of game time. By gathering empirical data for the player's response time and accuracy, we develop particle filter models. These models can then be used in real-time to categorise players into different ability and risk-taking levels.

  8. Understanding the Mismatch Between Coaches' and Players' Perceptions of Exertion

    NARCIS (Netherlands)

    Brink, Michel S; Kersten, Anna W; Frencken, Wouter G

    2016-01-01

    A mismatch between the intended training exertion by the coach and the perceived exertion by players is well established in sports. However, it is unknown if coaches are able to accurately observe exertion of individual players during training. Furthermore, the discrepancy in coaches' and players' p

  9. Kinanthropometric characteristics in teenager basketball players

    Directory of Open Access Journals (Sweden)

    Maria Abella del Campo

    2015-12-01

    Full Text Available Introduction: Basketball is a sport with a high heterogeneity anthropometric as playing position. Point guard is usually the lowest player but also the fastest. Guard is similar to point guard, faster and more agile than the others. Small forward has an intermediate height between the inside and outside players and it combines height with velocity. And center (pivot has a physical role, it has the highest and more muscle mass. The aim of this study is to describe the kinanthropometric profile of male cadet “Valencia Basket Club”. Material and Methods: A total of 20 male cadet basketball players were evaluated (15.35±0.59 years old. An anthropometrist level 1 took anthropometric measures according to the methodology of the International Society for the Advancement of Kinanthropometry (ISAK. Body composition was calculated according to the kinanthropometry consensus of the Kinanthropometry Spanish Group (GREC, somatotype with Heath-Carter’s method and adiposemuscular and cardiovascular risk index. Results: Differences in values of weight, height, skinfold and body composition from variables of sample and position were observed. Lower values were from point guard position and higher values were from center position. An increasing trend of these parameters was established in the following order: point guard, guard, small forward and center. Conclusions: The Valencia Basket Club cadet player overall somatotype is balance ectomorph. To know kinanthropometric profile may be beneficial to develop specific training and nutrition plans as well as to see evolution and characteristics for optimal performance

  10. Soccer skill development in talented players.

    Science.gov (United States)

    Huijgen, B C H; Elferink-Gemser, M T; Ali, A; Visscher, C

    2013-08-01

    The aim of the study was to gain insight into the development of soccer-specific skills and whether differences between talented players exist on the Loughborough Soccer Passing Test (LSPT). Two scores were derived from the LSPT: 1) execution time: time to complete 16 passes (speed) and 2) skill performance time: execution time including bonus and penalty time for accuracy. The study consisted of 2 parts, the first of which incorporated a quasi-longitudinal design with 270 talented players aged 10-18 years performing the LSPT (661 measurement occasions); multilevel modelling was applied. Secondly, differences between those players allowed to continue in the development program (selected, n=269) and players who were forced to leave (de-selected, n=50) were investigated using independent sample t-tests. The longitudinal data showed that the predicted execution time (i. e., speed) improved approximately 18% from age 10-18 years (Pskill performance time (i. e., combination of speed and accuracy) was predicted to improve approximately 32% (Pskill performance time (P0.05). In conclusion, in high-level youth soccer, the combination of speed and accuracy in soccer skills might be more important than speed alone. © Georg Thieme Verlag KG Stuttgart · New York.

  11. Mental rotation performance in male soccer players.

    Directory of Open Access Journals (Sweden)

    Petra Jansen

    Full Text Available It is the main goal of this study to investigate the visual-spatial cognition in male soccer players. Forty males (20 soccer players and 20 non-athletes solved a chronometric mental rotation task with both cubed and embodied figures (human figures, body postures. The results confirm previous results that all participants had a lower mental rotation speed for cube figures compared to embodied figures and a higher error rate for cube figures, but only at angular disparities greater than 90°. It is a new finding that soccer-players showed a faster reaction time for embodied stimuli. Because rotation speed did not differ between soccer-players and non-athletes this finding cannot be attributed to the mental rotation process itself but instead to differences in one of the following processes which are involved in a mental rotation task: the encoding process, the maintanence of readiness, or the motor process. The results are discussed against the background of the influence on longterm physical activity on mental rotation and the context of embodied cognition.

  12. Motivational Traits of Elite Young Soccer Players

    Science.gov (United States)

    Stewart, Craig; Meyers, Michael C.

    2004-01-01

    Among the most overlooked aspects in the development of elite young soccer players is that of specific psychological traits. Of those traits, motivation has important implications for programs whose objectives are identification and cultivation of young, skilled performers. The growth in popularity of soccer by youth and the successes experienced…

  13. Soccer Skill Development in Talented Players

    NARCIS (Netherlands)

    Huijgen, B. C. H.; Elferink-Gemser, M. T.; Ali, A.; Visscher, C.

    2013-01-01

    The aim of the study was to gain insight into the development of soccer-specific skills and whether differences between talented players exist on the Loughborough Soccer Passing Test (LSPT). Two scores were derived from the LSPT: 1) execution time: time to complete 16 passes (speed) and 2) skill per

  14. Football players, asset management & the unexploited potential of enhanced player engagement in football management & marketing

    DEFF Research Database (Denmark)

    Cortsen, Kenneth

    2014-01-01

    This article gives insights into why and how football brands (e.g. clubs and governing bodies) can benefit from enhancing the activation of players in football management and football marketing initiatives.......This article gives insights into why and how football brands (e.g. clubs and governing bodies) can benefit from enhancing the activation of players in football management and football marketing initiatives....

  15. Football players, asset management & the unexploited potential of enhanced player engagement in football management & marketing

    DEFF Research Database (Denmark)

    Cortsen, Kenneth

    2016-01-01

    This article gives insights into why and how football brands (e.g. clubs and governing bodies) can benefit from enhancing the activation of players in football management and football marketing initiatives.......This article gives insights into why and how football brands (e.g. clubs and governing bodies) can benefit from enhancing the activation of players in football management and football marketing initiatives....

  16. Anthropometric Characteristics of Spanish Professional Basketball Players

    Directory of Open Access Journals (Sweden)

    Vaquera Alejandro

    2015-06-01

    Full Text Available The study of elite basketball players’ anthropometric characteristics alongside those of body composition contributes significantly to their profiling as professional athletes and plays an important role in the selection process, as these characteristics can have a significant impact on performance. In the current study, 110 professional basketball players from a series of Spanish professional Leagues (ACB, LEB and EBA and youth level National Teams (U20 and U18 had their anthropometric profiles measured and compared to determine differences between them. Furthermore, all 110 players were divided into three different categories according to their playing position: guards, forwards and centres. The results obtained show no significant differences between players in different competitions in weight, height and the sum of skinfolds. Nonetheless, there were several differences related to body fat content (13.03% in ACB players and 10.52% in the lower categories and National Teams. There were also several differences found between the different playing positions amongst all playing levels in body mass (79.56 ± 2.41, 91.04 ± 1.51 and 104.56 ± 1.73 kg, height (182.28 ± 0.96, 195.65 ± 1.00 and 204.08 ± 0.67 cm, skinfold distribution and perimeters. However, there were no significant differences in body fat content between the different playing positions. The conclusions obtained from this study provide a better understanding to basketball specialists regarding the selection process of players at the elite level, especially on the transition from youth elite programs to men’s elite leagues.

  17. The architecture of the chess player's brain.

    Science.gov (United States)

    Hänggi, Jürgen; Brütsch, Karin; Siegel, Adrian M; Jäncke, Lutz

    2014-09-01

    The game of chess can be seen as a typical example for an expertise task requiring domain-specific training and experience. Despite intensive behavioural studies the neural underpinnings of chess performance and expertise are not entirely understood. A few functional neuroimaging studies have shown that expert chess players recruit different psychological functions and activate different brain areas while they are engaged in chess-related activities. Based on this functional literature, we predicted to find morphological differences in a network comprised by parietal and frontal areas and especially the occipito-temporal junction (OTJ), fusiform gyrus, and caudate nucleus. Twenty expert chess players and 20 control subjects were investigated using voxel-based and surface-based morphometry as well as diffusion tensor imaging. Grey matter volume and cortical thickness were reduced in chess players compared with those of control men in the OTJ and precunei. The volumes of both caudate nuclei were not different between groups, but correlated inversely with the years of chess playing experience. Mean diffusivity was increased in chess players compared with that of controls in the left superior longitudinal fasciculus and the Elo score (a chess tournament ranking) was inversely related to mean diffusivity within the right superior longitudinal fasciculus. To the best of our knowledge we showed for the first time that there are specific differences in grey and white matter morphology between chess players and control subjects in brain regions associated with cognitive functions important for playing chess. Whether these anatomical alterations are the cause or consequence of the intensive and long-term chess training and practice remains to be shown in future studies.

  18. Dynamic Visual Acuity Training in Cricket Players

    Directory of Open Access Journals (Sweden)

    Renee Edgar, B.Optom

    2015-04-01

    Full Text Available Background: Dynamic visual acuity (DVA is the ability of an observer to correctly identify details of a moving target and is considered to be important for tasks like driving. Dynamic Visual Acuity is better in athletes involved in sports such as basketball and baseball; however, no previous studies have considered the sport of cricket. We conducted a study to determine whether there was any difference in DVA between cricket and non-cricket players. Method: Dynamic visual acuity was measured by asking subjects to identify the orientation of the gap of a moving Landolt C target as a four-alternative forced-choice task. The Landolt C targets had confusion bars surrounding them. The participants in the study were tested twice with a break of seven weeks. In between the two measurements, participants underwent two training sessions (similar to the testing sessions, each three weeks apart. Results: The initial mean DVA for cricket players was 107.7 deg/sec, and the mean DVA for non-cricket players was 105.5 deg/sec, with a target size of 6/15. The subjects who participated in training (cricketers and non-cricketers improved in DVA by 41 deg/sec in contrast to the improvement in the non-training subjects of 18 deg/sec (p=0.0032. The cricketers who participated in the training improved in DVA by 44 deg/sec, whereas the cricketers who did not participate in the training improved by 19 deg/sec (p=0.0167. Conclusions: We found no significant difference in initial DVA between the cricket players and the non-cricket players. The training resulted in an extremely significant improvement in DVA performance by both the cricketers and non-cricketers.

  19. Evaluating Australian football league player contributions using interactive network simulation.

    Science.gov (United States)

    Sargent, Jonathan; Bedford, Anthony

    2013-01-01

    This paper focuses on the contribution of Australian Football League (AFL) players to their team's on-field network by simulating player interactions within a chosen team list and estimating the net effect on final score margin. A Visual Basic computer program was written, firstly, to isolate the effective interactions between players from a particular team in all 2011 season matches and, secondly, to generate a symmetric interaction matrix for each match. Negative binomial distributions were fitted to each player pairing in the Geelong Football Club for the 2011 season, enabling an interactive match simulation model given the 22 chosen players. Dynamic player ratings were calculated from the simulated network using eigenvector centrality, a method that recognises and rewards interactions with more prominent players in the team network. The centrality ratings were recorded after every network simulation and then applied in final score margin predictions so that each player's match contribution-and, hence, an optimal team-could be estimated. The paper ultimately demonstrates that the presence of highly rated players, such as Geelong's Jimmy Bartel, provides the most utility within a simulated team network. It is anticipated that these findings will facilitate optimal AFL team selection and player substitutions, which are key areas of interest to coaches. Network simulations are also attractive for use within betting markets, specifically to provide information on the likelihood of a chosen AFL team list "covering the line ". Key pointsA simulated interaction matrix for Australian Rules football players is proposedThe simulations were carried out by fitting unique negative binomial distributions to each player pairing in a sideEigenvector centrality was calculated for each player in a simulated matrix, then for the teamThe team centrality measure adequately predicted the team's winning marginA player's net effect on margin could hence be estimated by replacing him in

  20. Multi-Player and Multi-Choice Quantum Game

    Institute of Scientific and Technical Information of China (English)

    杜江峰; 李卉; 许晓栋; 周先意; 韩荣典

    2002-01-01

    We investigate a multi-player and multi-choice quantum game. We start from a two-player and two-choice game,and the result is better than its classical version. Then we extend this to N-player and N-choice cases. In the quantum domain, we provide a strategy with which players can always avoid the worst outcome. Also, by changing the value of the parameter of the initial state, the probabilities for players to obtain the best pay-off will be much higher than in its classical version.

  1. A comparative analysis of young tennis player target accuracy when using balls inflated under different pressures

    Directory of Open Access Journals (Sweden)

    Dmytro Krylov

    2017-06-01

    Full Text Available Purpose: make a comparative analysis of the target accuracy of ten-year tennis players in performing test exercises with balls with a pressure of 75% of the standard and balls with standard pressure. Material & Methods: in the study participated 8 tennis players of ten years of age, the group 5 years of training. In the course of the research, the following methods were used: analysis and generalization of literature sources, analysis of documentary materials, testing, method of expert evaluations. Results: replacing balls with a pressure of 75% of the standard for standard leads to a deterioration in the target accuracy of ten-year tennis players, which is a consequence of distortion of the technical characteristics of movements. Conclusion: results of the study indicate the need for correction of the technique of players of this age in the transition from balls with a pressure of 75% from the standard to standard.

  2. Prospective study of injury in volleyball players: 6 year results.

    Science.gov (United States)

    Pastor, M F; Ezechieli, M; Classen, L; Kieffer, O; Miltner, O

    2015-01-01

    The volleyball game has a high complexity and thus entails a lot of strain to the players. Due to this high and different training and competition strain comprehensive and individual training plans should be developed with competing training objectives in order to prevent injuries. The aim of the study was to analyse prospectively over six seasons the acute and overuse injuries of a German male professional volleyball team. The study included 34 male national league players from season the 2007/08 to 2012/13. All players received a sport medicine examination and a functional diagnosis before each season. Based on the results the players received an individual training plan. The players suffered 186 injuries. The prevalence of acute injuries was 1.94 per player and overuse injuries 0.64 per player. The incidence of acute injuries was 3.3/1000 h volleyball and overuse injuries 1.08/1000 h volleyball. The largest number of injuries was found in the spine. The players had most likely minor injuries. The players had significantly fewer injuries in their second season (1.92) than in their first season (3.25; p= 0.004). It could be concluded that volleyball is a sport with a relative low prevalence of injuries compared to other team sports. The prevalence of injury is 2.58 per player. Due to an injury a player dropped out 16.91 days per season. An individual training program seems to reduce the incidence of injury.

  3. Recognition accuracy by experienced men and women players of basketball.

    Science.gov (United States)

    Millslagle, Duane G

    2002-08-01

    This study examined 30 experienced basketball players' recognition accuracy by sex, playing position (guard, forward, and center), and situations in the game of basketball. The study used a perceptual cognitive paradigm in which subjects viewed slides of structured and unstructured game situations and accurately recognized the presence or absence of the basketball. A significant difference in recognition accuracy by sex, players' position, and structure of the game situation was found. Male players' recognition accuracy was better than the female players'. The recognition accuracy of subjects who played guard was better than that of subjects who played forward or center. The players' recognition accuracy was more accurate when observing structured plays versus unstructured plays. The conclusion of this study suggested that experienced basketball players differ in their cognitive and visual searching processes by sex and player position within the sport of basketball.

  4. Identification af explosive power factors as predictors of player quality in young female volleyball players.

    Science.gov (United States)

    Grgantov, Zoran; Milić, Mirjana; Katić, Ratko

    2013-05-01

    With the purpose of determining the factor structure of explosive power, as well as the influence of each factor on situational efficiency, 56 young female volleyball players were tested using 14 tests for assessing nonspecific and specific explosive power. By factor analysis, 4 significant factors were isolated which explained the total of over 80% of the common variability in young female volleyball players. The first factor was defined as volleyball-specific jumping, the second factor as nonspecific jumping and sprinting, the third factor as throwing explosive power, while the fourth factor was interpreted as volleyball-specific throwing and spiking speed from the ground. Results obtained by regression analysis in the latent space of explosive power indicate that the identified factors are good predictors of player quality in young female volleyball players. The fourth factor defined as throwing and spiking speed from the ground had the largest influence on player quality, followed by volleyball-specific jumping and nonspecific jumping and sprinting, and to a much lesser extent, by throwing explosive power The results obtained in this age group bring to the fore the ability of spiking and serving a ball of high speed, which hinders the opponents from playing those balls in serve reception and field defence. This ability, combined with a high standing vertical jump reach and spike approach vertical jump reach (which is the basis of the 1st varimax factor) enables successful performance of all volleyball elements by which points are won in complex 1 (spike) and complex 2 (serve and block). Even though the 2nd factor (nonspecific jumping and sprinting) has a slightly smaller impact on situational efficiency in young players, this ability provides preconditions i.e. preparation for successful realisation of all volleyball elements, so greater attention must be paid to perfecting it in young female volleyball players.

  5. Player Transformation of Educational Multiplayer Games

    DEFF Research Database (Denmark)

    Magnussen, Rikke; Misfeldt, Morten

    2004-01-01

    Children's great interest in multiplayer games has led to attempts to design educational multiplayer games. In this study, we have studied a test of an educational multiplayer game designed for mathematics education for children aged nine to twelve. In our observations, it became clear that pupils...... transformed the game to accommodate social interaction. With these transformed ways of playing the game, they managed to get to the top of the high score list while avoiding the educational parts of the game. Players transforming educational games to escape learning elements can be a problem when these games...... are used for formal education. In this paper we argue that player transformation of educational games can, however, be the basis of exciting and unconventional learning of valuable things, such as how to transform information technology to better accommodate social interaction....

  6. Common Injuries of Collegiate Tennis Players

    Directory of Open Access Journals (Sweden)

    Christian Wisdom Magtajas Valleser

    2017-09-01

    Full Text Available The purpose of this study is to determine the common injuries of Filipino collegiate tennis players; 110 varsity tennis players with a mean of 20 years old (SD ± 1.7 with an average playing experience of 12 years participated in the study. There was a 100% occurrence of at least one injury with an average rate of 5.98 injuries per person. The authors observed that the most commonly injured anatomical region is the lower extremity; ankles were recorded as the most commonly injured part. Other commonly injured areas included the shoulders and lower back. Furthermore, the most common injury type is tendinitis, sprains, and strains. The recorded injuries were mostly associated with overuse injuries, and the findings were similar to those of most other studies on tennis injuries. A larger sample size may provide more conclusive findings on tennis injuries, particularly in different levels of competition, such as recreational or professional athletes.

  7. Towards Generic Models of Player Experience

    DEFF Research Database (Denmark)

    Shaker, Noor; Shaker, Mohammad; Abou-Zleikha, Mohamed

    2015-01-01

    -dependent and their applicability is usually limited to the system and the data used for model construction. Establishing models of user experience that are highly scalable while maintaing the performance constitutes an important research direction. In this paper, we propose generic models of user experience in the computer games...... further examine whether generic features of player be- haviour can be defined and used to boost the modelling per- formance. The accuracies obtained in both experiments in- dicate a promise for the proposed approach and suggest that game-independent player experience models can be built.......Context personalisation is a flourishing area of research with many applications. Context personalisation systems usually employ a user model to predict the appeal of the context to a particular user given a history of interactions. Most of the models used are context...

  8. Macro-players in stock markets

    CERN Document Server

    Röhner, B M

    2005-01-01

    It is usually assumed that stock prices reflect a balance between large numbers of small individual sellers and buyers. However, over the past fifty years mutual funds and other institutional shareholders have assumed an ever increasing part of stock transactions: their assets, as a percentage of GDP, have been multiplied by more than one hundred. The paper presents evidence which shows that reactions to major shocks are often dominated by a small number of institutional players. Most often the market gets a wrong perception and inadequate understanding of such events because the relevant information (e.g. the fact that one mutual fund has sold several million shares) only becomes available weeks or months after the event, through reports to the Securities and Exchange Commission (SEC). Our observations suggest that there is a radical difference between small ($ 5% $) price changes which, on the contrary, may be caused by massive sales (or purchases) by a few players. This suggests that the mechanisms which a...

  9. Evolutionary game theory: molecules as players.

    Science.gov (United States)

    Bohl, Katrin; Hummert, Sabine; Werner, Sarah; Basanta, David; Deutsch, Andreas; Schuster, Stefan; Theissen, Günter; Schroeter, Anja

    2014-12-01

    In this and an accompanying paper we review the use of game theoretical concepts in cell biology and molecular biology. This review focuses on the subcellular level by considering viruses, genes, and molecules as players. We discuss in which way catalytic RNA can be treated by game theory. Moreover, genes can compete for success in replication and can have different strategies in interactions with other genetic elements. Also transposable elements, or "jumping genes", can act as players because they usually bear different traits or strategies. Viruses compete in the case of co-infecting a host cell. Proteins interact in a game theoretical sense when forming heterodimers. Finally, we describe how the Shapley value can be applied to enzymes in metabolic pathways. We show that game theory can be successfully applied to describe and analyse scenarios at the molecular level resulting in counterintuitive conclusions.

  10. Left ventricular biomechanics in professional football players.

    Science.gov (United States)

    von Lueder, T G; Hodt, A; Gjerdalen, G F; Steine, K

    2017-04-04

    Chronic exercise induces adaptive changes of left ventricular (LV) ejection and filling capacities which may be detected by novel speckle-tracking echocardiography (STE) and tissue Doppler imaging (TDI)-based techniques. A total of 103 consecutive male elite Norwegian soccer players and 46 age-matched healthy controls underwent echocardiography at rest. STE was used to assess LV torsional mechanics and LV systolic longitudinal strain (LS). Diastolic function was evaluated by trans-mitral blood flow, mitral annular velocities by TDI, and LV inflow propagation velocity by color M-mode. Despite similar global LS, players displayed lower basal wall and higher apical wall LS values vs controls, resulting in an incremental base-to-apex gradient of LS. Color M-mode and TDI-derived data were similar in both groups. Peak systolic twist rate (TWR) was significantly lower in players (86.4±2.8 vs controls 101.9±5.2 deg/s, Pplayers (-124.5±4.2 vs -106.9±6.7 deg/s) and peaked earlier during the cardiac cycle (112.7±0.8 vs 117.4±2.4% of systole duration, both Pplayers. Augmented diastolic wall strain (DWS), a novel measure of LV compliance in players, was associated with improved myocardial mechanical efficiency. The described myocardial biomechanics may underlie augmented exertional cardiac function in athletes and may have a potential role to characterize athlete's heart by itself or to distinguish it from hypertensive or hypertrophic cardiomyopathy. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. The El Dorado of Handball? Foreign Female Players Stay, while Domestic Players Return from Abroad.

    Science.gov (United States)

    Bon, Marta; Topič, Mojca Doupona; Šibila, Marko

    2016-04-01

    The main purpose of this research was to study the characteristics of migration in European women's handball based on the Slovenian example and to find the differences between the foreigners coming to Slovenia and the Slovenians transferring to foreign clubs. The research was based on 16 open face-to-face semi-structured interviews (8 Slovenians (age 29.5 ± 6.2 years) and 8 foreigners (age 35.5 ± 8.7 years)). We found out that the most powerful factor in foreigners was the financial one, while within Slovenian players it was their personal desire for progression within their sport, the club's reputation and poor conditions in their previous club. The results confirm that when making a decision on transfer, all players had the support of family and friends, while the clubs of foreign players were not as supportive. Most interviewees considered their careers successful and did not regret going abroad. The research indicates that the largest differences discovered between Slovenians and foreigners were that foreign female players chose to stay in the new country (Slovenia), while domestic players returned home after few years playing abroad. In conclusion, the results show that in top-level handball there are important differences between migration models which are based on nationality and also that the migration models change throughout time, which is largely connected with the socioeconomic events in the country of origin or transfer.

  12. Tibia and fibula fractures in soccer players.

    Science.gov (United States)

    Boden, B P; Lohnes, J H; Nunley, J A; Garrett, W E

    1999-01-01

    We performed a retrospective review of 31 athletes who sustained a fracture of the lower leg from a direct blow while playing soccer. Fifteen fractures involved both the tibia and fibula 11 only the tibia, and 5 only the fibula. Information was collected using a standardized questionnaire. The mean follow-up from the time of injury was 30 months. Injuries typically occurred in young, competitive athletes during game situations. The mechanisms were broadly classified into several categories: contact during a slide tackle (13, 42%), a collision with the goalkeeper (8, 26%), two opposing players colliding while swinging for a loose ball (7, 23%), or a player being kicked by a standing opponent (3, 10%). The majority of fractures (26, 90%) occurred while the athletes were wearing shin guards. The point of impact was with the shin guard prior to the fracture in 16 cases (62%). Return to competitive soccer averaged 40 weeks for combined tibia and fibula fractures, 35 weeks for isolated tibia fractures, and 18 weeks for isolated fibula fractures. Injuries were associated with a high incidence of major complications (12 out of 31, 39%), especially in concurrent tibia and fibula fractures (8 out of 15, 50%). These findings suggest that lower leg fractures in soccer players are serious injuries, often necessitating a prolonged recovery time. In addition, this study questions the ability of shin guards to protect against fractures.

  13. EVALUATING AUSTRALIAN FOOTBALL LEAGUE PLAYER CONTRIBUTIONS USING INTERACTIVE NETWORK SIMULATION

    Directory of Open Access Journals (Sweden)

    Jonathan Sargent

    2013-03-01

    Full Text Available This paper focuses on the contribution of Australian Football League (AFL players to their team's on-field network by simulating player interactions within a chosen team list and estimating the net effect on final score margin. A Visual Basic computer program was written, firstly, to isolate the effective interactions between players from a particular team in all 2011 season matches and, secondly, to generate a symmetric interaction matrix for each match. Negative binomial distributions were fitted to each player pairing in the Geelong Football Club for the 2011 season, enabling an interactive match simulation model given the 22 chosen players. Dynamic player ratings were calculated from the simulated network using eigenvector centrality, a method that recognises and rewards interactions with more prominent players in the team network. The centrality ratings were recorded after every network simulation and then applied in final score margin predictions so that each player's match contribution-and, hence, an optimal team-could be estimated. The paper ultimately demonstrates that the presence of highly rated players, such as Geelong's Jimmy Bartel, provides the most utility within a simulated team network. It is anticipated that these findings will facilitate optimal AFL team selection and player substitutions, which are key areas of interest to coaches. Network simulations are also attractive for use within betting markets, specifically to provide information on the likelihood of a chosen AFL team list "covering the line".

  14. Sympathetic enhancement in futsal players but not in football players after repeated sprint ability test.

    Science.gov (United States)

    Chen, Yung-Sheng; Liao, Chih-Jung; Lu, Wan-An; Kuo, Cheng-Deng

    2015-01-01

    Heart rate variability (HRV) can disclose the specific adaptation of sympathovagal modulation to exercise. This study investigated the change in HRV measures after anaerobic and aerobic intermittent exercises in university football and futsal players. 36 male university students with physically active lifestyle (n=14), football (n=12), and futsal (n=10) participated in this study. The participants completed the repeated sprint ability (RSA) test and Yo-Yo (YY) intermittent recovery test level 1 in randomised order. ECG signals of the participants were recorded in supine position 15 min before and 30 min after exercises. Before exercise, and 5 and 30 min after exercise, the blood pressures were also taken. In the RSA protocol, the percentage changes in normalised high-frequency power (nHFP) were significantly decreased, while the percentage changes in the very low/high frequency power ratio (VLHR) and low/high frequency power ratio (LHR) were significantly increased in futsal players after exercise, as compared with the controls. No significant changes in all HRV indices were found in the YY protocol, except the respiratory frequency. After exercise, the percent decrease in vagal modulation in futsal players was significantly reduced, while the percentage increase in sympathetic modulation in futsal players was significantly enhanced in the RSA test, but not in the YY test, as compared with the control group. The increase in sympathetic activity and the decrease in vagal activity in the futsal players were greater than the corresponding increase and decrease in the football players in the RSA test.

  15. Vitamin C and E Supplementation Effects in Professional Soccer Players Under Regular Training

    OpenAIRE

    Stancanneli Mirtes; Neto Joaquim; Lazarim Fernanda L; Silva Fernando C.; Hohl Rodrigo; Zoppi Claudio C; Macedo Denise V

    2006-01-01

    Exercise training is known to induce an increase in free radical production potentially leading to enhanced muscle injury. Vitamins C and E are well known antioxidants that may prevent muscle cell damage. The purpose of this study was to determine the effects of these supplemental antioxidant vitamins on markers of oxidative stress, muscle damage and performance of elite soccer players. Ten male young soccer players were divided into two groups. Supplementation group (n=5) received vitamins C...

  16. Vascular Health in American Football Players: Cardiovascular Risk Increased in Division III Players

    Directory of Open Access Journals (Sweden)

    Deborah L. Feairheller

    2016-01-01

    Full Text Available Studies report that football players have high blood pressure (BP and increased cardiovascular risk. There are over 70,000 NCAA football players and 450 Division III schools sponsor football programs, yet limited research exists on vascular health of athletes. This study aimed to compare vascular and cardiovascular health measures between football players and nonathlete controls. Twenty-three athletes and 19 nonathletes participated. Vascular health measures included flow-mediated dilation (FMD and carotid artery intima-media thickness (IMT. Cardiovascular measures included clinic and 24 hr BP levels, body composition, VO2 max, and fasting glucose/cholesterol levels. Compared to controls, football players had a worse vascular and cardiovascular profile. Football players had thicker carotid artery IMT (0.49 ± 0.06 mm versus 0.46 ± 0.07 mm and larger brachial artery diameter during FMD (4.3±0.5 mm versus 3.7±0.6 mm, but no difference in percent FMD. Systolic BP was significantly higher in football players at all measurements: resting (128.2±6.4 mmHg versus 122.4±6.8 mmHg, submaximal exercise (150.4±18.8 mmHg versus 137.3±9.5 mmHg, maximal exercise (211.3±25.9 mmHg versus 191.4±19.2 mmHg, and 24-hour BP (124.9±6.3 mmHg versus 109.8±3.7 mmHg. Football players also had higher fasting glucose (91.6±6.5 mg/dL versus 86.6±5.8 mg/dL, lower HDL (36.5±11.2 mg/dL versus 47.1±14.8 mg/dL, and higher body fat percentage (29.2±7.9% versus 23.2±7.0%. Division III collegiate football players remain an understudied population and may be at increased cardiovascular risk.

  17. Vascular Health in American Football Players: Cardiovascular Risk Increased in Division III Players

    Science.gov (United States)

    Feairheller, Deborah L.; Aichele, Kristin R.; Oakman, Joyann E.; Neal, Michael P.; Cromwell, Christina M.; Lenzo, Jessica M.; Perez, Avery N.; Bye, Naomi L.; Santaniello, Erica L.; Hill, Jessica A.; Evans, Rachel C.; Thiele, Karla A.; Chavis, Lauren N.; Getty, Allyson K.; Wisdo, Tia R.; McClelland, JoAnna M.; Sturgeon, Kathleen; Chlad, Pam

    2016-01-01

    Studies report that football players have high blood pressure (BP) and increased cardiovascular risk. There are over 70,000 NCAA football players and 450 Division III schools sponsor football programs, yet limited research exists on vascular health of athletes. This study aimed to compare vascular and cardiovascular health measures between football players and nonathlete controls. Twenty-three athletes and 19 nonathletes participated. Vascular health measures included flow-mediated dilation (FMD) and carotid artery intima-media thickness (IMT). Cardiovascular measures included clinic and 24 hr BP levels, body composition, VO2 max, and fasting glucose/cholesterol levels. Compared to controls, football players had a worse vascular and cardiovascular profile. Football players had thicker carotid artery IMT (0.49 ± 0.06 mm versus 0.46 ± 0.07 mm) and larger brachial artery diameter during FMD (4.3 ± 0.5 mm versus 3.7 ± 0.6 mm), but no difference in percent FMD. Systolic BP was significantly higher in football players at all measurements: resting (128.2 ± 6.4 mmHg versus 122.4 ± 6.8 mmHg), submaximal exercise (150.4 ± 18.8 mmHg versus 137.3 ± 9.5 mmHg), maximal exercise (211.3 ± 25.9 mmHg versus 191.4 ± 19.2 mmHg), and 24-hour BP (124.9 ± 6.3 mmHg versus 109.8 ± 3.7 mmHg). Football players also had higher fasting glucose (91.6 ± 6.5 mg/dL versus 86.6 ± 5.8 mg/dL), lower HDL (36.5 ± 11.2 mg/dL versus 47.1 ± 14.8 mg/dL), and higher body fat percentage (29.2 ± 7.9% versus 23.2 ± 7.0%). Division III collegiate football players remain an understudied population and may be at increased cardiovascular risk. PMID:26904291

  18. MUSCLE DAMAGE AFTER A TENNIS MATCH IN YOUNG PLAYERS

    Directory of Open Access Journals (Sweden)

    R.V. Gomes

    2014-07-01

    Full Text Available The present study investigated changes in indirect markers of muscle damage following a simulated tennis match play using nationally ranked young (17.6 ± 1.4 years male tennis players. Ten young athletes played a 3-hour simulated match play on outdoor red clay courts following the International Tennis Federation rules. Muscle soreness, plasma creatine kinase activity (CK, serum myoglobin concentration (Mb, one repetition maximum (1RM squat strength, and squat jump (SJ and counter movement jump (CMJ heights were assessed before, immediately after, and 24 and 48 h after the simulated match play. All parameters were also evaluated in a non-exercised group (control group. A small increase in the indirect markers of muscle damage (muscle soreness, CK and Mb was detected at 24-48 hours post-match (p<0.05. A marked acute decrement in neuromuscular performance (1RM squat strength: -35.2 ± 10.4%, SJ: -7.0 ± 6.0%, CMJ: -10.0 ± 6.3% was observed immediately post-match (p<0.05. At 24 h post-match, the 1RM strength and jump heights were not significantly different from the baseline values. However, several players showed a decrease of these measures at 24 h after the match play. The simulated tennis match play induced mild muscle damage in young players. Coaches could monitor changes in the indirect markers of muscle damage to assess athletes’ recovery status during training and competition.

  19. Energy Balance during Taekwondo Practice in Elite Male Taekwondo Players.

    Science.gov (United States)

    Cho, Kang Ok; Garber, Carol Ewing; Lee, Sukho; Kim, Yeon Soo

    2013-03-01

    The goal of this study was to evaluate energy expenditure and dietary intake of nutrients during Taekwondo practice in elite Korean male Taekwondo players. Elite Korean male high school (high school player: HP; n = 59) and college players (college player: CP; n = 58) wore an accelerometer to measure energy expenditure and recorded their daily dietary intake for nutritional analysis over the course of five days. Nutritional adequacy ratios for total energy (0.82), vitamin C (0.97), calcium (0.78), and folate (0.75) were below recommended levels for all players. When comparing daily nutrient intake and energy expenditure between HP and CP, the HP group had significantly higher total calorie intake (402.7 kcal, p Taekwondo practice, the total energy expenditure (151.2 kcal, p = 0.001), total activity counts (130,674 counts, p = 0.038) and energy expenditure during Taekwondo practice (257.7 kcal, p Taekwondo players.

  20. Heart rate and activity profile for young female soccer players

    OpenAIRE

    2008-01-01

    The physical and physiological demands of high-level male soccer have been studied extensively, while few studies have investigated the demands placed on females during match-play, however, there is no information available about the heart rate and activity profile of young female soccer players during match play. Therefore, the aim of this study was to examine cardiovascular (heart-rates HR) and physical demands of young female soccer players during a match. Players were observed during a fr...

  1. Temperamental Predictive Factors for Success in Korean Professional Baseball Players

    OpenAIRE

    Kang, Kyoung Doo; Han, Doug Hyun; Hannon, James C.; Hall, Morgan S.; Choi, Jae Won

    2015-01-01

    Objective In this five-year cohort study, we hypothesize that factors of temperament and character in professional baseball players predict the speed of obtaining success and the quality of success as well as anxiety control. Methods Participants included 120 male rookie players from the Korea Baseball Organization (KBO) and 107 male non-players with no history of playing baseball. The personality/characters and state/trait anxieties of participants were assessed with the Temperament and Char...

  2. Nutritional Habits & Knowledge in the Division I Collegiate Football Player

    OpenAIRE

    Hale, Mallory

    2013-01-01

    Objectives: Athlete’s nutritional habits and knowledge can directly affect their performance. The purpose of this study is to investigate the nutritional habits and knowledge of the Division I collegiate football player. Methods: The participants of this study are male Division I college football players at Utah State University. The athletes included 45 players ranging from 18-26 and include freshman through seniors. Results: Over eighty six percent of the athletes were unaware that a ...

  3. Towards Player Adaptivity in a Serious Game for Conflict Resolution

    DEFF Research Database (Denmark)

    Grappiolo, C.; Cheong, Yun-Gyung; Togelius, J.

    2011-01-01

    to resolve this type of conflict, the underlying system generates level content automatically which adapts to player experience and behaviour. Preliminary results demonstrate the efficiency of the procedural content generation mechanism in guiding the training of players towards targeted learning objectives.......We present a technology demonstrator for an adaptive serious game for teaching conflict resolution and discuss the research questions associated with the project. The prototype is a single-player 3D mini-game which simulates a resource management conflict scenario. In order to teach the player how...

  4. Arthroscopic Shoulder Surgery in Female Professional Tennis Players

    Science.gov (United States)

    Young, Simon W.; Safran, Marc R.; Dakic, Jodie; Nguyen, Michael L.; Stroia, Kathleen

    2013-01-01

    Objectives: Recent publications have highlighted the relatively poor outcome of other overhead athletes, particularly baseball players, with regard to return to sports at the same or higher level after shoulder surgery. However, true assessment of their ability when returning to sport is not as clear. Further, ability to return to other overhead sports has not been reported. Our objective was to assess outcome and time to return to previous level of function following shoulder surgery in professional tennis players. Methods: The records of all female tennis players on the Women’s Tennis Association (WTA) professional circuit between January 2008 and June 2010 were reviewed to identify players who underwent shoulder surgery on their dominant (serving) shoulder. Details of the surgery including date, procedures performed, and complications were recorded. The primary outcomes were ability and time to return to professional play, and if they were able to return to their previous level of function, as determined by singles ranking. Pre and post-operative singles rankings were used to determine rate and completeness of return to preoperative function. Their highest ranking pre-injury, post operatively, and the time to return to pre-injury ranking were evaluated. Results: During the study period eight professional women tennis players from the WTA underwent shoulder surgery on their dominant arm. All surgery was performed arthroscopically, 7 out of 8 players had more than one procedure performed during the surgery. In total, 3 players underwent debridement of a partial rotator cuff tear and 2 players underwent repair of a complete supraspinatus tear. Three players had an anterior labral repair or reconstruction for anterior instability, and one player underwent repair of a SLAP lesion. Two players underwent neurolysis of a suprascapular nerve, and three players in total underwent a subacromial decompression. All players (100%) returned to professional play. The mean

  5. A Multi-agent player for Settlers of Catan

    OpenAIRE

    2008-01-01

    There are many games that have been a challenge to Research in Artificial Intelligence. One such game is Settlers of Catan (SoC). The purpose of this thesis is to develop a Multi-agent player for SoC. Although it is difficult to focus on all the dimensions of the game during implementation, therefore a good enough solution is proposed. An emphasis is placed on building a good trader for the player. Once a working solution had been built, the player was tested against other players which inclu...

  6. Understanding the Mismatch Between Coaches' and Players' Perceptions of Exertion.

    Science.gov (United States)

    Brink, Michel S; Kersten, Anna W; Frencken, Wouter G P

    2017-04-01

    A mismatch between the training exertion intended by a coach and the exertion perceived by players is well established in sports. However, it is unknown whether coaches can accurately observe exertion of individual players during training. Furthermore, the discrepancy in coaches' and players' perceptions has not been explained. To determine the relation between intended and observed training exertion by the coach and perceived training exertion by the players and establish whether on-field training characteristics, intermittent endurance capacity, and maturity status explain the mismatch. During 2 mesocycles of 4 wk (in November and March), rating of intended exertion (RIE), rating of observed exertion (ROE), and rating of perceived exertion (RPE) were monitored in 31 elite young soccer players. External and internal training loads were objectively quantified with accelerometers (PlayerLoad) and heart-rate monitors (TRIMPmod). Results of an interval shuttle-run test (ISRT) and age at peak height velocity (APHV) were determined for all players. RIE, ROE, and RPE were monitored in 977 training sessions. The correlations between RIE and RPE (r = .58; P players will do and what they actually did on the field. When doing this, they consider the intermittent endurance capacity of individual players.

  7. Executive functions predict the success of top-soccer players.

    Science.gov (United States)

    Vestberg, Torbjörn; Gustafson, Roland; Maurex, Liselotte; Ingvar, Martin; Petrovic, Predrag

    2012-01-01

    While the importance of physical abilities and motor coordination is non-contested in sport, more focus has recently been turned toward cognitive processes important for different sports. However, this line of studies has often investigated sport-specific cognitive traits, while few studies have focused on general cognitive traits. We explored if measures of general executive functions can predict the success of a soccer player. The present study used standardized neuropsychological assessment tools assessing players' general executive functions including on-line multi-processing such as creativity, response inhibition, and cognitive flexibility. In a first cross-sectional part of the study we compared the results between High Division players (HD), Lower Division players (LD) and a standardized norm group. The result shows that both HD and LD players had significantly better measures of executive functions in comparison to the norm group for both men and women. Moreover, the HD players outperformed the LD players in these tests. In the second prospective part of the study, a partial correlation test showed a significant correlation between the result from the executive test and the numbers of goals and assists the players had scored two seasons later. The results from this study strongly suggest that results in cognitive function tests predict the success of ball sport players.

  8. Executive functions predict the success of top-soccer players.

    Directory of Open Access Journals (Sweden)

    Torbjörn Vestberg

    Full Text Available While the importance of physical abilities and motor coordination is non-contested in sport, more focus has recently been turned toward cognitive processes important for different sports. However, this line of studies has often investigated sport-specific cognitive traits, while few studies have focused on general cognitive traits. We explored if measures of general executive functions can predict the success of a soccer player. The present study used standardized neuropsychological assessment tools assessing players' general executive functions including on-line multi-processing such as creativity, response inhibition, and cognitive flexibility. In a first cross-sectional part of the study we compared the results between High Division players (HD, Lower Division players (LD and a standardized norm group. The result shows that both HD and LD players had significantly better measures of executive functions in comparison to the norm group for both men and women. Moreover, the HD players outperformed the LD players in these tests. In the second prospective part of the study, a partial correlation test showed a significant correlation between the result from the executive test and the numbers of goals and assists the players had scored two seasons later. The results from this study strongly suggest that results in cognitive function tests predict the success of ball sport players.

  9. Player Collaboration in the Explorative Sound Environment ToneInk

    DEFF Research Database (Denmark)

    Hansen, Anne-Marie S.; Andersen, Hans Jørgen; Raudaskoski, Pirkko Liisa

    2016-01-01

    In the present paper, ToneInk, a prototype of a music based play scenario that investigates player collaboration, is introduced. ToneInk is an explorative sound environment that differs from the majority of music based games in that players can collaborate and be creative in the way they express...... mutual awareness, and in general were more passive when they needed to monitor a screen interface that supported the sound environment. Player collaboration was strongest when players negotiated rhythm, while the negotiation of melody was temporally offset and consisted of long individual explorations....

  10. Membongkar Veto Player dalam Politik Kepartaian Indonesia Menuju Pemilu 2014

    Directory of Open Access Journals (Sweden)

    Arya Budi

    2014-05-01

    Full Text Available The article explains about how party elites, then identified as veto players, in Indonesia’s 2014 election organize themselve into party organization. The authority institutionalization of the veto player creates a decisional and positional quadrant of each party in terms of party politics of 2014 election. The findings of veto player pattern in such a party politics confirm forms of a centripetal force of politics in party organization. Finally, veto player behavior causes a spectrum of political cybernetics among political parties based on its turbulence, cohesiveness, and switching elites.

  11. Concussion knowledge in high school football players.

    Science.gov (United States)

    Cournoyer, Janie; Tripp, Brady L

    2014-01-01

    Participating in sports while experiencing symptoms of a concussion can be dangerous. An athlete's lack of knowledge may be one factor influencing his or her decision to report symptoms. In an effort to enhance concussion education among high school athletes, legislation in Florida has attempted to address the issue through parental consent forms. To survey high school varsity football players to determine their level of knowledge about concussions after the initiation of new concussion-education legislation. Cross-sectional study. Descriptive survey administered in person during a team meeting. A total of 334 varsity football players from 11 high schools in Florida. Participants completed a survey and identified the symptoms and consequences of a concussion among distractors. They also indicated whether they had received education about concussions from a parent, formal education, neither, or both. The most correctly identified symptoms were headache (97%), dizziness (93%), and confusion (90%), and the most correctly identified consequence was persistent headache (93%). Participants reported receiving education from their parents (54%) or from a formal source (60%). Twenty-five percent reported never receiving any education regarding concussions. No correlations were found between the method of education and the knowledge of symptoms or consequences of concussion. The high school football players we surveyed did not have appropriate knowledge of the symptoms and consequences of concussions. Nausea or vomiting, neck pain, grogginess, difficulty concentrating, and personality or behavioral changes were often missed by participants, and only a small proportion correctly identified brain hemorrhage, coma, and death as possible consequences of inappropriate care after a concussion. Even with parents or guardians signing a consent form indicating they discussed concussion awareness with their child, 46% of athletes suggested they had not.

  12. A new game plan for C players.

    Science.gov (United States)

    Axelrod, Beth; Handfield-Jones, Helen; Michaels, Ed

    2002-01-01

    It's a big driver of business success, but one that executives are loath to talk about: upgrading the talent pool by weeding out "C" players from management. These aren't the incompetent or unethical managers whom organizations dismiss without a backward glance; C performers deliver results that are acceptable--barely--but they fail to innovate or to inspire the people they lead. The authors of The War for Talent have studied what it takes to upgrade an organization's talent pool. In this article, they explore the hidden costs of tolerating under-performance and acknowledge the reasons why executives may shy away from dealing decisively with C players. They recommend that organizations take an "iron hand in a velvet glove" approach to managing subpar performers. That is, companies should establish rigorous, disciplined processes for assessing and dealing with low-performing managers but still treat them with respect. The authors outline three ironhanded steps. First, executives must identify C players by evaluating their talents and distributing employee performances along an assessment curve. Second, executives must agree on explicit action plans that articulate the improvements or changes that C performers must achieve within six to 12 months. And third, executives should hold managers accountable for carrying out the action plans. Without such discipline, procrastination, rationalization, and inaction will prevail. The authors also emphasize the need for the "velvet glove." Executives must ensure that low performers are treated with dignity, so they should offer candid feedback, instructive coaching, and generous severance packages and outplacement support. The authors' approach isn't about being tough on people; it's about being relentlessly focused on performance.

  13. Comparison of Shoulder Strength in Routinely Trained Badminton Players and Non-Badminton Players

    Directory of Open Access Journals (Sweden)

    Wong Zhen Feng

    2017-06-01

    Full Text Available Background: Shoulder pain is a common reason for patients to seek medical help in any healthcare center. Shoulder pain is influenced by a few factors such as gender, posture during daily activities, aging and psychological factors. Based on the study of Epidemiology of Injuries and Prevention Strategies in Competitive Swimmers, shoulder pain due to shoulder injuries can be reduced by strengthening the shoulder muscle. Badminton has become one of the most popular sports in Asia, especially in Indonesia. This study was conducted to determine if badmintonis able to strengthen the shoulder muscle group. Methods: A cross-sectional analytic experimental study was conducted on September 2015 at Lodaya Badminton Training Center and Bale Padjadjaran of Universitas Padjadjaran. Subjects were 30 healthy male routinely trained badminton players and 30 non-badminton players who voluntarily follow the rstudy procedures. Strength measurement procedures were provided to the subjects after getting informed consent.  Data analysis was performed using T-test. Results: The shoulder strength  in routinely trained badminton players was significantly different from  non-badminton players (P<0.05. Conclusions: Shoulder strength can be improved through routine training of badminton to reduce risk of shoulder injury.   DOI: 10.15850/amj.v4n2.1083

  14. Probabilistic one-player Ramsey games via deterministic two-player games

    CERN Document Server

    Belfrage, Michael; Spöhel, Reto

    2009-01-01

    Consider the following probabilistic one-player game: The board is a graph with $n$ vertices, which initially contains no edges. In each step, a new edge is drawn uniformly at random from all non-edges and is presented to the player, henceforth called Painter. Painter must assign one of $r$ available colors to each edge immediately, where $r \\geq 2$ is a fixed integer. The game is over as soon as a monochromatic copy of some fixed graph $F$ has been created, and Painter's goal is to 'survive' for as many steps as possible before this happens. We present a new technique for deriving upper bounds on the threshold of this game, i.e., on the typical number of steps Painter will survive with an optimal strategy. More specifically, we consider a deterministic two-player variant of the game where the edges are not chosen randomly, but by a second player Builder. However, Builder has to adhere to the restriction that, for some real number $d$, the ratio of edges to vertices in all subgraphs of the evolving board neve...

  15. DIFFERENCES IN FUNCTIONAL AND MOTOR ABILITIES OFYOUNG FOOTBALL PLAYERS, BASKETBALL AND VOLLEYBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Franja Fratrić

    2009-11-01

    Full Text Available The main goal of this research is to determine whether and what differences exist between the three groups of subjects (high-quality football, volleyball and basketball cadets and youth age, in the motoric and functional abilities, as well as to identify dif- ferences between subgroups within each sport. The sample consists of 61 volleyball, 31 basketball player and football player 31 (total n = 123 male, cadet and youth age are members of local clubs. Subjects were born between 01.01.1991 and 12.12.1994. The sample of variables are the values of 17 tests for the evaluation of functional and mobile status. The Motor-functional status on the basis of the results of secondary value of foot- ball, basketball and volleyball make a clear conclusion that the football players showed the best results in almost all the tests and that they had the smallest disbalance in the power of certain groups of muscles.The football players hve the highest homogeneity.

  16. Meniscal ossicle in a professional soccer player.

    Science.gov (United States)

    Ogassawara, R; Zayni, R; Orhant, E; Noel, E; Fournier, Y; Hager, J-P; Chambat, P; Sonnery-Cottet, B

    2011-06-01

    Meniscal ossicles are an unusual finding and a rare cause for knee pain. They are often initially diagnosed as a loose body, chondrocalcinosis or meniscal calcification within the knee joint. Few cases have been reported in the literature. We present a case of a meniscal ossicle with an associated femoral cartilage lesion in a healthy 26-year-old male professional soccer player who presented with swelling and pain. The purpose of this article is to discuss the origins, radiological features, clinical symptoms and prognosis of meniscal ossicles.

  17. Payoff Shares in Two-Player Contests

    Directory of Open Access Journals (Sweden)

    Samuel Häfner

    2016-09-01

    Full Text Available In imperfectly discriminating contests with symmetric valuations, equilibrium payoffs are positive shares of the value of the prize. In contrast to a bargaining situation, players’ shares sum to less than one because a residual share of the value is lost due to rent dissipation. In this paper, we consider contests with two players and investigate the relationship between these equilibrium shares and the parameters of a class of asymmetric Tullock contest success functions. Our main finding is that any players’ shares that sum up to less than one can arise as the unique outcome of a pure-strategy Nash equilibrium for appropriate parameters.

  18. Acing common skin problems in tennis players.

    Science.gov (United States)

    Basler, R S; Garcia, M A

    1998-12-01

    The following measures can help prevent skin disorders in tennis players: wearing properly fitted shoes to avoid tennis toe, talon noir, and calluses; applying lubricants to protect against blisters and chafing; washing skin thoroughly to reduce the risk of acne mechanica; and wearing a hat and sunscreen to guard against photoinjury. 'Stringer's fingers' can be prevented by breaking the habit of adjusting the racket strings after each point. Should these disorders become troublesome, conservative treatments are usually effective. For example, calluses may be carefully pared, and pain from a subungual hemorrhage can be relieved by piercing the toenail with a hot paper clip.

  19. Predicting Player Churn In the Wild

    DEFF Research Database (Denmark)

    Hadiji, Fabian; Sifa, Rafet; Drachen, Anders;

    2014-01-01

    a crucial value, allowing developers to obtain data-driven insights to inform design, development and marketing strategies. One of the key challenges is modeling and predicting player churn. This paper presents the first cross-game study of churn prediction in Free-to-Play games. Churn in games is discussed...... with the individual retention model for each game in the dataset used, we develop a broadly applicable churn prediction model, which does not rely on gamedesign specific features. The presented classifiers are applied on a dataset covering five free-to-play games resulting in high accuracy churn prediction....

  20. Match analysis and player characteristics in rugby sevens.

    Science.gov (United States)

    Ross, Alex; Gill, Nicholas; Cronin, John

    2014-03-01

    Rugby sevens is a contact sport contested by two teams of seven players who compete over two 7-min halves, most frequently played in a tournament style. The IRB Sevens World Series is thought of as the preeminent rugby sevens competition in the world and has grown in competitiveness from its inception in 2000. The decision to include rugby sevens in the 2016 Olympics is likely to increase the global profile and participation in the game. Many rugby sevens players concurrently compete in 15-a-side rugby union as backs and loose forwards; however, a continued increase in the popularity of rugby sevens will likely see the emergence of the specialist rugby sevens player. Often thought of as the abbreviated version of rugby union, rugby sevens is played under nearly identical laws and on the same field dimensions as the 15-man code. However, research has shown the movement demands of rugby sevens and rugby union are dissimilar, with rugby sevens players spending a larger proportion of the game running at high intensity (≥ 5 m s(-1)). Given the dissimilarity in match demands in conjunction with differences in the competition structure between the codes, it appears the considerable depth of literature specific to performance in rugby union may be of little value for the preparation of rugby sevens players. Investigations of the physical characteristics of rugby sevens players show backs are lighter and shorter than forwards, while players across all positions possess a lean body composition. International rugby sevens players have similar speed characteristics to rugby union backs across distances of 10-30 m; however, rugby sevens players appear to have superior intermittent aerobic endurance. Despite being of likely importance, little is known of the strength and power characteristics of rugby sevens players. Research into the speed and aerobic endurance characteristics of rugby sevens players has not distinguished between backs and forwards and, as such, it is unclear

  1. Sex-specific differences in injury types among basketball players

    Directory of Open Access Journals (Sweden)

    Ito E

    2014-12-01

    Full Text Available Eri Ito, Jun Iwamoto, Koichiro Azuma, Hideo MatsumotoInstitute for Integrated Sports Medicine, Keio University School of Medicine, Tokyo, JapanAbstract: The purpose of the present study was to investigate sex-specific differences in injury types among basketball players. According to our database, during the 20-year period between October 1991 and June 2011, 1,219 basketball players (640 males and 579 females consulted our sports medicine clinic; in total, 1,414 injuries in basketball players (729 injuries in males and 685 injuries in females were recorded. The mean age of patients was 19.6 years. The most common injury site was the knee, followed by the foot and ankle, lower back, and upper extremities. There was a higher proportion of female players presenting with a knee injury, compared with male players (50.4% vs 41.7%, and a lower proportion of female players presenting with an upper extremity injury (5.1% vs 9.7%. The proportion of anterior cruciate ligament injury in the 10–19-year-old age group was higher among female players than among male players (45.9% vs 22.1%, while the proportions of Osgood–Schlatter disease in the 10–19-year-old age group and jumper's knee (patellar and femoral tendinopathy in the 20–29-year-old age group were higher among male players than among female players (12.5% vs 1.8% and 14.6% vs 3.7%, respectively. However, the proportions of other injuries did not differ significantly between male and female players. The present observational study, which was performed using a retrospective case-series design, showed the existence of sex-specific differences in knee injuries sustained while participating in basketball.Keywords: sports injury, sex, anterior cruciate ligament injury, Osgood–Schlatter disease, basketball

  2. Strength asymmetry of the shoulders in elite volleyball players.

    Science.gov (United States)

    Hadzic, Vedran; Sattler, Tine; Veselko, Matjaž; Markovic, Goran; Dervisevic, Edvin

    2014-01-01

    Volleyball players are reported to have shoulder strength imbalances. Previous authors have primarily investigated small samples of male players at a single skill level, without considering playing position, and with inconsistent findings. To evaluate shoulder strength asymmetry and a history of shoulder injury in a large sample of professional volleyball players of both sexes across different playing positions and skill levels. Descriptive laboratory study. A sample of 183 volleyball players (99 men, 84 women). We assessed shoulder internal-rotator and external-rotator concentric strength at 60°/s using an isokinetic dynamometer and dominant-nondominant differences in shoulder strength and strength ratios using repeated-measures analyses of variance. Peak torque was normalized for body mass and external-rotation/internal-rotation concentric strength. Internal-rotation strength was asymmetric in favor of the dominant side in both sexes, regardless of previous shoulder injury status. Male volleyball players had a lower shoulder strength ratio on the dominant side, regardless of previous shoulder injury status. However, this finding was valid only when hand dominance was taken into account. Female volleyball players playing at a higher level (ie, first versus second division) were 3.43 times more likely to have an abnormal strength ratio. Playing position was not associated with an abnormal shoulder strength ratio or strength asymmetry. In male volleyball players, the external-rotation/internal-rotation strength ratio of the dominant shoulder was lower, regardless of playing position, skill level, or a previous shoulder injury. In female players, the ratio was less only in those at a higher skill level. Although speculative, these findings generally suggest that female volleyball players could have a lower risk of developing shoulder-related problems than male volleyball players. Isokinetic shoulder testing may reveal important information about the possible risk

  3. Scapula Kinematics of Youth Baseball Players

    Directory of Open Access Journals (Sweden)

    Oliver Gretchen

    2015-12-01

    Full Text Available Literature has revealed the importance of quantifying resting scapular posture in overhead athletes as well as quantifying scapular kinematics during dynamic movement. Prior to this project much of the attention in throwing research had been focused on the position of the humerus without description of the positioning of the scapula. Therefore, it was the purpose of this study to present scapular kinematics during pitching in youth baseball players. Twenty-five youth baseball players (age 11.3 + 1.0 years; body height 152.4 + 9.0 cm; body mass 47.5 + 11.3 kg, with no history of injury, participated in the study. Scapular kinematics at the events of maximum humeral external rotation (MER and maximum humeral internal rotation (MIR during the pitching motion were assessed three-dimensionally while pitching fastballs for strikes. Results revealed that at the event of MER, the scapula was in a position of retraction, upward rotation and a posterior tilt. While at the event of MIR, the scapula was protracted, upward rotated and tilted anteriorly.

  4. Scapula Kinematics of Youth Baseball Players.

    Science.gov (United States)

    Oliver, Gretchen; Weimar, Wendi

    2015-12-22

    Literature has revealed the importance of quantifying resting scapular posture in overhead athletes as well as quantifying scapular kinematics during dynamic movement. Prior to this project much of the attention in throwing research had been focused on the position of the humerus without description of the positioning of the scapula. Therefore, it was the purpose of this study to present scapular kinematics during pitching in youth baseball players. Twenty-five youth baseball players (age 11.3 + 1.0 years; body height 152.4 + 9.0 cm; body mass 47.5 + 11.3 kg), with no history of injury, participated in the study. Scapular kinematics at the events of maximum humeral external rotation (MER) and maximum humeral internal rotation (MIR) during the pitching motion were assessed three-dimensionally while pitching fastballs for strikes. Results revealed that at the event of MER, the scapula was in a position of retraction, upward rotation and a posterior tilt. While at the event of MIR, the scapula was protracted, upward rotated and tilted anteriorly.

  5. Sport commitment in adolescent soccer players

    Directory of Open Access Journals (Sweden)

    Noelia Belando Pedreño

    2016-03-01

    Full Text Available The aim of this study was to contribute to the postulates of the self-determination theory, the hierarchical model of intrinsic and extrinsic motivation by Vallerand, and social goals. A structural regression model was estimated to analyze the relations between social goals (responsibility and relationships, praise for autonomous behavior, satisfaction of the basic psychological needs and intrinsic motivation in commitment to sport. A sample of 264 young Spanish soccer players aged between 14 and 16 (M =14.74, SD =.77 participated in the study. Structural Equation Modeling results showed that the social responsibility goal, the social relationship goal and praise for autonomous behavior predicted perceived competence. Furthermore, the relationship goal also predicted the need for relatedness. Satisfaction of the basic psychological needs for competence and relatedness predicted intrinsic motivation. Intrinsic motivation positively predicted future commitment to sport. These results highlighted the importance of social goals, praise for autonomous behavior and psychological mediators in encouraging greater commitment in young soccer players. Future research should focus on the coach’s role in generating greater commitment to sport through the development of intervention methodologies based on social goals.

  6. Acute and sub-acute effects of repetitive kicking on hip adduction torque in injury-free elite youth soccer players

    DEFF Research Database (Denmark)

    Jensen, Jesper; Bandholm, Thomas; Hölmich, Per;

    2014-01-01

    Hip adduction strength is important for kicking and acceleration in soccer players. Changes in hip adduction strength may therefore have an effect on soccer players' athletic performance. The purpose of this study was to investigate the acute and sub-acute effects of a kicking drill session on hip...... strength, concerning isometric hip adduction, abduction and flexion torque of the kicking leg and the supporting leg. Ten injury-free male elite soccer players, mean ± s age of 15.8 ± 0.4 years participated. All players underwent a specific 20 min kicking drill session, comprising 45 kicks. The players...

  7. Protective Equipment and Player Characteristics Associated With the Incidence of Sport-Related Concussion in High School Football Players

    Science.gov (United States)

    McGuine, Timothy A.; Hetzel, Scott; McCrea, Michael; Brooks, M. Alison

    2015-01-01

    Background The incidence of sport-related concussion (SRC) in high school football is well documented. However, limited prospective data are available regarding how player characteristics and protective equipment affect the incidence of SRC. Purpose To determine whether the type of protective equipment (helmet and mouth guard) and player characteristics affect the incidence of SRC in high school football players. Design Cohort study; Level of evidence, 2. Methods Certified athletic trainers (ATs) at each high school recorded the type of helmet worn (brand, model, purchase year, and recondition status) by each player as well as information regarding players’ demographics, type of mouth guard used, and history of SRC. The ATs also recorded the incidence and days lost from participation for each SRC. Incidence of SRC was compared for various helmets, type of mouth guard, history of SRC, and player demographics. Results A total of 2081 players (grades 9–12) enrolled during the 2012 and/or 2013 football seasons (2287 player-seasons) and participated in 134,437 football (practice or competition) exposures. Of these players, 206 (9%) sustained a total of 211 SRCs (1.56/1000 exposures). There was no difference in the incidence of SRC (number of helmets, % SRC [95% CI]) for players wearing Riddell (1171, 9.1% [7.6%–11.0%]), Schutt (680, 8.7% [6.7%–11.1%]), or Xenith (436, 9.2% [6.7%–12.4%]) helmets. Helmet age and recondition status did not affect the incidence of SRC. The rate of SRC (hazard ratio [HR]) was higher in players who wore a custom mouth guard (HR = 1.69 [95% CI, 1.20–2.37], P football players. Players who had sustained an SRC within the previous 12 months were more likely to sustain an SRC than were players without a history of SRC. Sports medicine providers who work with high school football players need to realize that factors other than the type of protective equipment worn affect the risk of SRC in high school players. PMID:25060072

  8. Gender Differences in Coping among Elite Table Tennis Players

    Science.gov (United States)

    Kirimoglu, Huseyin

    2011-01-01

    The current study aims to investigate the explanatory power of social support and coping in relation to a competitive sport event between male and female table tennis players. 246 university students table tennis players (120 men and 126 women) from different region and part of Turkey were invited to participate in a survey study included the…

  9. Development of repeated sprint ability in talented youth basketball players.

    NARCIS (Netherlands)

    Wierike, S.C. te; Jong, M.C. de; Tromp, E.J.; Vuijk, P.J.; Lemmink, K.A.; Malina, R.M.; Elferink-Gemser, M.T.; Visscher, C.

    2013-01-01

    Factors affecting repeated sprint ability (RSA) were evaluated in a mixed-longitudinal sample of 48 elite basketball players 14 to 19 years of age (16.1±1.7 years). Players were observed on six occasions during the 2008-2009 and 2009-2010 seasons. Three basketball-specific field tests were administe

  10. Relative risk for concussions in young female soccer players.

    Science.gov (United States)

    Strand, Sarah; Lechuga, David; Zachariah, Thomas; Beaulieu, Kathryn

    2015-01-01

    The objective of this study was to determine the relative risk and reported symptoms of concussions in 11- to 13-year-old, female soccer players. For this, a survey to compare the reported incidence of concussion in age-matched female soccer players to nonsoccer players was performed. The survey included 342 girls between the ages of 11 and 13: 195 were involved in an organized soccer team and 147 were not involved in organized soccer but were allowed to participate in any other sport or activity. A total of 94 of the 195 soccer players, or 48%, reported at least one symptom consistent with a concussion. The most prevalent symptom for these girls was headache (84%). A total of 34 of the 147 nonsoccer players, or 23%, reported at least one symptom consistent with a concussion in the previous six months. These results determined that the relative risk of probable concussions among 11- to 13-year-old, female soccer players is 2.09 (p concussions in young female soccer players is significantly higher than in a control group of nonsoccer players of the same sex and age.

  11. Development of repeated sprint ability in talented youth basketball players.

    NARCIS (Netherlands)

    Koen A.P.M. Lemmink; S.C. te Wierike; E.J. Tromp; M.T. Elferink-Gemser; M.C. de Jong; R.M. Malina; P.J. Vuijk; C. Visscher

    2013-01-01

    Factors affecting repeated sprint ability (RSA) were evaluated in a mixed-longitudinal sample of 48 elite basketball players 14 to 19 years of age (16.1±1.7 years). Players were observed on six occasions during the 2008-2009 and 2009-2010 seasons. Three basketball-specific field tests were

  12. [Muscular trunk stability in professional and amateur volleyball players].

    Science.gov (United States)

    Miltner, O; Siebert, C; Tschaepe, R; Maus, U; Kieffer, O

    2010-03-01

    The aim of this study was to analyse the efficiency of muscular activity in the trunk stabilisation of professional volleyball players compared to a group of amateur hobby players. The results were compared amongst the groups as well as with a reference group consisting of asymptomatic individuals. The question to be answered was whether or not professional volleyball players possess a characteristic strength profile in their trunk musculature and if differences exist with regard to the individuals' competitive playing level. In this comparative study 12 professional volleyball players (German Bundesliga) and 18 non-professional volleyball players were analysed with regard to their isometric strength profile in all three planes. The reference group was provided by the Proxomed company, which had previously analysed healthy untrained individuals (n = 1045) of various age groups. A sports-specific profile for the musculature of volleyball players revealed a significant reduction in the flexion and rotation strength as well as a well-developed lateral flexion strength (highly significant when compared to the reference group). With reference to the level played, better strength values in flexion and lateral flexion were found among the professional athletes. Professional volleyball players present with a characteristic trunk musculature strength profile. A detailed analysis of the muscle strength of the spine as part of a sports medicine work-up could prove helpful in preventing injuries and overuse problems in professional and hobby volleyball players.

  13. Player Collaboration in the Explorative Sound Environment ToneInk

    DEFF Research Database (Denmark)

    Hansen, Anne-Marie; Andersen, Hans Jørgen; Raudaskoski, Pirkko Liisa

    2016-01-01

    mutual awareness, and in general were more passive when they needed to monitor a screen interface that supported the sound environment. Player collaboration was strongest when players negotiated rhythm, while the negotiation of melody was temporally offset and consisted of long individual explorations....

  14. Differences in energy capacities between tennis players and runners.

    Science.gov (United States)

    Novak, Dario; Vucetić, Vlatko; Zugaj, Sanja

    2013-05-01

    The primary purpose of this study was to determine differences between elite athletes and tennis players in order to provide a clearer picture regarding the energy demands in modern tennis. Forty-eight (48) athletes and 24 tennis players from Croatian national leagues were compared in morphological and physiological parameters of an all-out incremental treadmill test with gas exchange measurements. Tennis players' HRmax (192.96+/-7.75 bpm) shows values that are most different to 400-meters sprinters (200.13+/-6.95 bpm). Maximum running speed of tennis players on the treadmill (vmax) is no different with the speed achieved by sprinters, while there are significant differences among other athletes. Values in running speed at anaerobic threshold (vAnT) show no statistically significant difference with the values for athlete sprinters and 400-m sprinters. Values of RvO2max for tennis players indicate significant similarities with athlete sprinters and 400-m sprinters while the values of RvO2AnT are nearly identical with the values for sprinters and show no statistically significant differences (ptennis players approximate most different those of the middle and long distance runners. This singles out the possible importance of the anaerobic capacity and the high level of sprint endurance in tennis players. Knowing these characteristics is the basis for planning and implementing training systems that will enable the increase and optimal usage of energy capacities of tennis players in possibly improving sports results.

  15. Translucent Players: Explaining Cooperative Behavior in Social Dilemmas

    Directory of Open Access Journals (Sweden)

    Valerio Capraro

    2016-06-01

    Full Text Available In the last few decades, numerous experiments have shown that humans do not always behave so as to maximize their material payoff. Cooperative behavior when non-cooperation is a dominant strategy (with respect to the material payoffs is particularly puzzling. Here we propose a novel approach to explain cooperation, assuming what Halpern and Pass call translucent players. Typically, players are assumed to be opaque, in the sense that a deviation by one player in a normal-form game does not affect the strategies used by other players. But a player may believe that if he switches from one strategy to another, the fact that he chooses to switch may be visible to the other players. For example, if he chooses to defect in Prisoner's Dilemma, the other player may sense his guilt. We show that by assuming translucent players, we can recover many of the regularities observed in human behavior in well-studied games such as Prisoner's Dilemma, Traveler's Dilemma, Bertrand Competition, and the Public Goods game.

  16. Labor Market Structure and Salary Determination among Professional Basketball Players.

    Science.gov (United States)

    Wallace, Michael

    1988-01-01

    The author investigates the labor market structure and determinants of salaries for professional basketball players. An expanded version of the resource perspective is used. A three-tiered model of labor market segmentation is revealed for professional basketball players, but other variables also are important in salary determination. (Author/CH)

  17. The Mental Skills Training of University Soccer Players

    Science.gov (United States)

    Sadeghi, Hassan; Omar-Fauzee, Mohd-Sofian; Jamalis, Marjohan; Ab-Latif, Rozita; Cheric, Majid Chahrdah

    2010-01-01

    The purpose of this study is to identify the kind of mental skills training needed most by the university soccer players. Eight male university football players (aged 25 to 36) from one large university in Kuala Lumpur agreed to participate in this study. On average, they have 10 years of playing experience. All of them have signed the informed…

  18. Differences in Soccer Kick Kinematics between Blind Players and Controls

    Science.gov (United States)

    Giagazoglou, Paraskevi; Katis, Athanasios; Kellis, Eleftherios; Natsikas, Christos

    2011-01-01

    The purpose of the current study was to examine the kinematic differences during instep soccer kicks between players who were blind and sighted controls. Eleven male soccer players who were blind and nine male sighted performed instep kicks under static and dynamic conditions. The results indicated significantly higher (p less than 0.05) ball…

  19. Playing time between senior rugby players of different ethnic groups ...

    African Journals Online (AJOL)

    Discovery High Performance Centre, Sports Science Institute of South Africa, and MRC/UCT Research Unit for Exercise ... nutritional advice, life skills and technical rugby coaching. The ... Players were given feedback on their performance in each of the 3 ..... the skill acquisition that is required by a high-level adult player.

  20. Development of repeated sprint ability in talented youth basketball players.

    NARCIS (Netherlands)

    Koen A.P.M. Lemmink; S.C. te Wierike; E.J. Tromp; M.T. Elferink-Gemser; M.C. de Jong; R.M. Malina; P.J. Vuijk; C. Visscher

    2013-01-01

    Factors affecting repeated sprint ability (RSA) were evaluated in a mixed-longitudinal sample of 48 elite basketball players 14 to 19 years of age (16.1±1.7 years). Players were observed on six occasions during the 2008-2009 and 2009-2010 seasons. Three basketball-specific field tests were administe

  1. Analysis of motor activities of professional soccer players.

    Science.gov (United States)

    Andrzejewski, Marcin; Chmura, Jan; Pluta, Beata; Kasprzak, Andrzej

    2012-06-01

    The objective of this study was to determine the distance covered by professional soccer players during matches with the use of the computerized match analysis system Amisco Pro® (version 1.0.2, Nice, France). Kinematic examination included the specification of the distance covered by 31 players participating in 4 matches in the Union of European Football Association Cup competitions during the 2008-2009 season. Data were analyzed based on players' positions on the pitch, changes in the players' motor activity intensity level, and match period (first or second half). The results of statistical analysis revealed that the average total distance covered by all players (n = 31) was 11,288 ± 734 m. With respect to the player's position on the pitch, the midfielders traveled the longest average distance (11,770 ± 554 m) during the game. This was 3% longer than the distance achieved by the attackers at 11,377 ± 584 m, and 7% longer than that achieved by the defenders 10,932 ± 728 m. The analysis of physical loads on soccer players during a match is highly useful for training individualization. It provides a tool for effective planning and for recording the loads on players, which is an indispensable element of modern coaching.

  2. Neuropsychological consequence of soccer play in adolescent U.K. School team soccer players.

    Science.gov (United States)

    Stephens, Richard; Rutherford, Andrew; Potter, Douglas; Fernie, Gordon

    2010-01-01

    To assess mild head injury effects in adolescent soccer players, neuropsychological performance across school team soccer players, rugby players and noncontact sport players was assessed in a quasi-experimental cross-sectional design. One hundred eighty-five males were tested (ages 13-16; response rate 55%) and 86 contributed data to the analyses after exclusion for recent concussion and overlapping sports participation. Soccer players showed lower premorbid intellectual functioning, but neither soccer players nor rugby players showed neuropsychological decrement compared with noncontact sport players. Cumulative heading did not predict neuropsychological performance. While no specific attribute of soccer was linked with neuropsychological impairment, head injury predicted reduced attention for all participants.

  3. Evaluating the heading in professional soccer players by playing positions.

    Science.gov (United States)

    Erkmen, Nurtekin

    2009-09-01

    The aim of this study is to evaluate the accuracy and coordination of heading in professional soccer players of different positions. A total of 243 professional soccer players were examined for the study. The Federation Internationale de Football Association Medical Assessment and Research Center (F-MARC) test battery was used to evaluate heading in soccer players. In the heading of the ball thrown from middle of the goal, forwards were better than goalkeepers (p heading of the ball thrown from the right side of the goalpost, defenders were better than goalkeepers (p heading of goalkeepers being worse than the others; goalkeepers use their hands in both training and matches, whereas for forwards and defensive players being better than goalkeepers depends mainly on their positions in soccer. Trainers and coaches should give place specific training programs to improve heading ability in the training schedule of soccer players at a professional level.

  4. Shoulder injuries in rugby players: mechanisms, examination, and rehabilitation.

    Science.gov (United States)

    Helgeson, Kevin; Stoneman, Paul

    2014-11-01

    The sport of rugby is growing in popularity for players at the high school and collegiate levels. This article will provided the sports therapist with an introduction to the management of shoulder injuries in rugby players. Rugby matches results in frequent impacts and leveraging forces to the shoulder region during the tackling, scrums, rucks and maul components of the game. Rugby players frequently sustain contusion and impact injuries to the shoulder region, including injuries to the sternoclavicular, acromioclavicular (AC), and glenohumeral (GH) joints. Players assessed during practices and matches should be screened for signs of fracture, cervical spine and brachial plexus injuries. A three phase program will be proposed to rehabilitate players with shoulder instabilities using rugby specific stabilization, proprioception, and strengthening exercises. A plan for return to play will be addressed including position-specific activities. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. A Method for Using Player Tracking Data in Basketball to Learn Player Skills and Predict Team Performance.

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    Brian Skinner

    Full Text Available Player tracking data represents a revolutionary new data source for basketball analysis, in which essentially every aspect of a player's performance is tracked and can be analyzed numerically. We suggest a way by which this data set, when coupled with a network-style model of the offense that relates players' skills to the team's success at running different plays, can be used to automatically learn players' skills and predict the performance of untested 5-man lineups in a way that accounts for the interaction between players' respective skill sets. After developing a general analysis procedure, we present as an example a specific implementation of our method using a simplified network model. While player tracking data is not yet available in the public domain, we evaluate our model using simulated data and show that player skills can be accurately inferred by a simple statistical inference scheme. Finally, we use the model to analyze games from the 2011 playoff series between the Memphis Grizzlies and the Oklahoma City Thunder and we show that, even with a very limited data set, the model can consistently describe a player's interactions with a given lineup based only on his performance with a different lineup.

  6. Bone Mineral Density of Adolescent Female Tennis Players and Nontennis Players

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    Kevser Ermin

    2012-01-01

    Full Text Available The purpose of this study was to determine differences in bone mineral density (BMD among adolescent female tennis players (TPs and nontennis players (NTPs and to assess body composition as a predictor variable of BMD. Nineteen female TPs and 19 female NTPs, ages 14 to 18 years, participated in this study. Lumbar spine, total hip, femoral neck, forearms BMD, and body composition were assessed using dual-energy X-ray absorptiometry (DXA. Lumbar spine and total hip BMD measurements for TP were greater than NTP. However, these differences were not statistically significant (=0.37 and 0.12, resp.. TP had significantly greater femoral neck BMD than NTPs (=0.02. This difference might play an important role in preventing osteoporosis and decreasing the risk of fractures at the hip later in life.

  7. EFFECT OF A TRAINING PROGRAM ON THE IMPROVEMENT OF BASKETBALL PLAYERS' DECISION MAKING

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    Francisco Alarc\\u00F3n

    2009-01-01

    Full Text Available The aim of this study was to analyse whether a tactical training program based on a constructivist model can improve decision making related to keeping control of the ball for a men's senior basketball team composed of ten players. The dependent variables were: player distribution around the ball, and achieving support on both sides of the ball at an effective passing distance. Data collection was made through observational analysis utilizing a previously validated tool. A pretest-posttest design without a control group was used. Results demonstrated an improvement in decision making after the posttest for both the number of support players near the player with the ball, as it increased from 85% in the pretest to 100% in the posttest, and the number of collective or team actions around the player with the ball (from 5% to 76.5% with highly significant differences. The primary conclusion is that a training program for teaching team tactics based on a constructivist model has a positive influence on players' capability to facilitate the pass to their teammates.

  8. Sympathetic enhancement in futsal players but not in football players after repeated sprint ability test

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    Chen, Yung-Sheng; Liao, Chih-Jung; Lu, Wan-An; Kuo, Cheng-Deng

    2015-01-01

    Background Heart rate variability (HRV) can disclose the specific adaptation of sympathovagal modulation to exercise. This study investigated the change in HRV measures after anaerobic and aerobic intermittent exercises in university football and futsal players. Method 36 male university students with physically active lifestyle (n=14), football (n=12), and futsal (n=10) participated in this study. The participants completed the repeated sprint ability (RSA) test and Yo-Yo (YY) intermittent r...

  9. Coach/player relationships in tennis.

    Science.gov (United States)

    Prapavessis, H; Gordon, S

    1991-09-01

    The present study examined the variables that predict coach/athlete compatibility. Compatibility among a sample of 52 elite tennis coach/player dyads was assessed using a sport adapted version of Schutz's (1966) Fundamental Interpersonal Relations Orientation-Behaviour (FIRO-B), a sport adapted version of Fiedler's (1967) Least Preferred Co-worker scale (LPC), and Chelladurai and Saleh's (1980) Leadership Scale for Sport (LSS). Self-ratings of the quality of the interaction were obtained from both coach and athlete. Multiple-regression analyses using self-rating scores as the dependent measure were carried out to determine which variables best predicted the degree of compatibility. The sole inventory that significantly predicted compatibility was the LSS. More specifically, the discrepancy between the athlete's preferences and perceptions on the autocratic dimension was the best predictor. Implications for tennis coaches and recommendations for future research in this area are discussed.

  10. Gamification in Fostering Creativity: Player Type Approach

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    Marius Kalinauskas

    2015-02-01

    Full Text Available Purpose – to analyze gamification, as the method for promoting creativity in individual and collective levels with the respect to player types.Design/methodology/approach – This research serves as a general review/viewpoint which seeks to examine collective creativity as a phenomenon and gamification as the tool for promoting individual and collective creativity. The paper is based on the comparative analysis of scientific literature and related sources from game design, psychology, business and entertainment.Findings – Although the gamification is gaining more public attention, there is a lack of studies which would reveal its relations in fostering individual and collective creativity. One of the main goals of any gamified content is to raise the engagement into activities in non-game contexts. The objective of creative work is to come up with some ideas, methods or tools which would be significantly new and innovative in the case of a certain issue. The theory of “flow” is used widely in explaining the working principles of gamification. In this state, the information absorption rates are increased and the group or individual is immersed into performed activities. This may lead to prolonged periods while accumulating knowledge, and thus, improving creative capabilities in the specific domain. However, creative performance in different fields has various approaches. It is also related to personal characteristics. The success of gamification is also dependent on the types of “players” which participate in the activity. Having the common picture of personality type in creative performance and in game based tasks may allow creating gamification strategy for optimal engagement into creative work according to the features of a person.Research limitations/implications – There are very few empirical studies which would support correlation between experiencing the “flow” state and a raise of creativity. The idea of unified

  11. Cellular Players in Skeletal Muscle Regeneration

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    Laura Cristina Ceafalan

    2014-01-01

    Full Text Available Skeletal muscle, a tissue endowed with remarkable endogenous regeneration potential, is still under focused experimental investigation mainly due to treatment potential for muscle trauma and muscular dystrophies. Resident satellite cells with stem cell features were enthusiastically described quite a long time ago, but activation of these cells is not yet controlled by any medical interventions. However, after thorough reports of their existence, survival, activation, and differentiation there are still many questions to be answered regarding the intimate mechanism of tissue regeneration. This review delivers an up-to-date inventory of the main known key players in skeletal muscle repair, revealed by various models of tissue injuries in mechanical trauma, toxic lesions, and muscular dystrophy. A better understanding of the spatial and temporal relationships between various cell populations, with different physical or paracrine interactions and phenotype changes induced by local or systemic signalling, might lead to a more efficient approach for future therapies.

  12. Morphological classification of novice female volleyball players

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    José António Ribeiro Maia

    2003-12-01

    Full Text Available The characteristics of physique have been the subject of several studies in sport sciences because high-level competitive sports place maximum demands on the physical constitution of players. Furthermore, the specifi c function performed by a player in a game may be related to a particular modality. The goals of this study were: (1 to describe and to compare, from a somatic point of view, the physiques of 71 female volleyball players at beginner levels A and B (aged 12-14 years; and (2 to identify the components of somatic structure that best differentiate the athletics by level of experience. In order to evaluate the players’ somatic structure,we performed 21 measurements including: weight and height, diameters, circumferences, upper and lower limb measurements and skinfolds thicknesses. Discriminant function analysis (DFA was used to identify the power of variables classifi cation. No difference was found in physique between level A and level B players. They were classifi ed by somatotype as mesomorphic endomorphs (A = 4.76 - 3.78 - 1.85; and B = 4.37 - 4.02 - 1.88. RESUMO As características morfológicas têm sido objeto de vários estudos em Ciências Desporto, pelo fato de o fenômeno do desporto de alta competição exigir o máximo da estrutura física dos atletas e pela expectativa da função que o atleta desempenha em jogo. O presente estudo teve como objetivo: (1 descrever e comparar, do ponto de vista somático, a estrutura morfológica de 71 atletas de voleibol do sexo feminino dos escalões de formação A e B (entre os 12 e 14 anos de idade; (2 identifi car os componentes da estrutura somática que melhor diferenciam as atletas de níveis distintos. Para a avaliação da estrutura somática das atletas foram efetuadas 21 avaliações, incluindo além do peso e altura, comprimento dos membros, perímetros, diâmetros e pregas de adiposidade subcutâneas. Com o intuito de verifi car o poder discriminatório das variáveis na

  13. Stem Cells and Neuroprotection: Understanding the Players

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    Virginia Pearce

    2010-09-01

    Full Text Available The use of neuroprotective therapies begs the question of how such therapies could affect preexisting stem cell populations within the host, as well as those introduced through cell-replacement therapy. Multiple mechanisms may mediate stem cell responses to neuroprotectants such as host/donor age and gender, cellular lineage/differentiation status, and mitochondrial dynamics. Current therapeutic sources for stem cells are embryonic, somatic, or induced pluripotent, with very little known about the effects of gender, age, cell type, and mitochondrial dynamics. With the advent of therapies to stimulate and recruit endogenous stem cells or transplant donor cells into damage areas in the hopes of recuperative regeneration of lost neurons, it is important to discuss mechanisms that dictate the winning players in the neuroprotection game. This review will focus on our current understanding of the characteristics of renewing stem cells that may affect neuroprotection.

  14. University Football Players, Postural Stability, and Concussions.

    Science.gov (United States)

    Graves, Barbara Sue

    2016-02-01

    Concussion in football athletes is certainly more prevalent and has potentially serious outcomes. With current concerns and increasing return-to-play issues, additional assessment focus is needed. Division 1 college football athletes, from 18 to 20.9 years (n = 177; age, 19.7 ± 1.2 years; height, 182.3 ± 4.5 cm; weight, 97.3 ± 10.6 kg), before fall practice, over a period of 3 years, underwent baseline postural stability testing (sensory organization test [SOT], NeuroCom). Individuals, who were diagnosed with a concussion (headache, dizziness, fatigue, confusion, or loss of consciousness) during practice or actual competition (n = 15; age, 18.9 ± 0.9 years; height, 181.8 ± 2.5 cm; weight, 86.6 ± 3.6 kg), underwent serial evaluation after injury and 24 hours after concussion. As soon as the player was considered asymptomatic, the test was completed on the first and 14th day. A control group of noninjured male athletes (n = 15; age, 19.1 ± 0.4 years; height, 178.2 ± 3.2 cm; weight, 78.6 ± 2.1 kg) were tested for the same time frame. This particular study was only one part of the total evaluation conducted for the concussed athlete's return to play. Results indicated that the concussion group had a statistically significant (p = 0.037) change from their baseline SOT score and the control group (p = 0.025). This change remained significant until day 14 of posttesting. These data indicate that the SOT, when available, may be a positive additional assessment of concussed college-aged football players. Professionals, when dealing with concussion in competitive sports, do need to continue to work together, but awareness of SOT assessments may also contribute to the return-to-play decisions.

  15. SPORTS SHOES PURCHASE INTENTION AMONG MALAYSIAN VOLLEYBALL PLAYERS VS. NON-VOLLEYBALL PLAYERS: A CONCEPTUAL PAPER

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    GOH PIN SIANG

    2013-12-01

    Full Text Available The purpose of this study is to advance the understanding of volleyball players’ purchase intention toward sport shoes by investigating the relationship between the independent variables (endorsement, advertising, pricing and electronic word-of-mouth and purchase intention. Descriptive research and causal research will be used as the research design, thus questionnaire and experimentation will be used to obtain data. Primary data in this study is attained by distributing the questionnaire to the Malaysian volleyball players throughout several volleyball tournament venues in Malaysia. The experiment will be conducted by comparing two groups of respondents, including volleyball players and non-volleyball players. This study is limited to several independent variables such as endorsement, advertising, pricing and electronic word-of-mouth. This study is significant for marketers for solving the challenges faced in the sport industry. It also helps to identify consumers’ purchase preferences for sport shoes. The marketer would understand more about their targeted customers’ intentions to purchase, thus the sport industry related with sport marketing in Malaysia might gain more profit.

  16. Cervical range of motion and proprioception in rugby players versus non-rugby players.

    Science.gov (United States)

    Lark, Sally D; McCarthy, Peter W

    2007-06-01

    In this study, we examined the effects of number of years of playing rugby on neck function. Active cervical spine range of motion and proprioception were assessed in 14 non-rugby-playing but trained sportsmen (mean age 28 years, s = 7) and 46 rugby players (26 rugby forwards: mean age 26 years, s = 5; mean years played 14 years; 20 backs: mean age 24 years, s = 5; mean years played 14 years). Active cervical range of motion in flexion, extension, left and right lateral flexion, plus left and right rotation were measured using a cervical range of motion device. The ability to reposition the head in a central position with eyes closed was taken as a measure of proprioception. Results show that rugby forwards generally had the least active cervical range of motion, particularly neck extension (forwards, 43 degrees ; backs, 55 degrees ; controls, 58 degrees ), with the decrement correlating with the number of years played. In addition, repositioning was significantly worse in rugby players after neck extension than non-rugby players (6 degrees vs. 3 degrees ). The active cervical range of motion of rugby forwards is similar to that of whiplash patients, suggesting that participation in rugby can have an effect on neck range of motion that is equivalent to chronic disability. Reduced active cervical range of motion could also increase the likelihood of injury and exacerbate age-related neck problems.

  17. Soccer and Relative Age Effect: A Walk among Elite Players and Young Players

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    Manuel Jacob Sierra-Díaz

    2017-01-01

    Full Text Available Grouping people according to chronological age is popular in fields such as education and sport. Athletes who are born in the first months of the year usually have cognitive and physical development differences in contrast to those born in the last months of the same year. That is why competitive teams tend to select older players more often than youngsters. Age differences between athletes born in the same year as well as an over-representation of older players are known as the Relative Age Effect. This effect is extensively described in young and elite team sports such as basketball, volleyball or, ice-hockey, as well as in soccer. The purpose of this study is to examine the state-of-the-art of the Relative Age Effect in youth and elite soccer players. This review summarizes recent research articles on the Relative Age Effect related to competitive soccer from 2010 to 2016. The systematic literature search was conducted in four databases: SPORTDiscus, Medline, EBSCO host and Google Scholar. Although causes and final solutions have not been clearly achieved yet, it is necessary to continue investigating this phenomenon in order to provide a starting point for future research.

  18. Kinetic Post-match Fatigue in Professional and Youth Soccer Players During the Competitive Period

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    Djaoui

    2016-03-01

    Full Text Available Background No previous research has analysed kinetic fatigue of elite adult players and elite youth players during the competitive period. Objectives The aim of the present study was to analyse kinetic post-match fatigue in professional and youth soccer players during the competitive period. Materials and Methods resting heart rate (HRrest, post-effort recovery heart rate (HRrecovery, rate of perceived exertion fatigue (RPEf, muscle soreness and blood samples with creatine kinase (CK and resting lactate (La from nine professional soccer players were measured immediately before, 24 hour and 48 hour after two official French first league matches (Ligue 1 whereas RPEf, HRrest, and 20m speed performance (speed-20 m were measured in ten U-17 elite players immediately before, 24 hour and 48h after a friendly match. Results for professionals, a soccer match elevated all physiological markers during the next 24 hours (P < 0.05; only HRrecovery remained significantly different 48 hours after the match (P < 0.05 whereas there was no variation of HRrest, RPEf, and speed-20m, which were elevated until 24h and got back to reference values 48 hours after the match (P < 0.05 for the U17 players. Comparing the two groups, HRrest results remained lower all the time for professionals, and RPEf was lower for U-17, 24 hours after the match (P < 0.05. Conclusions Independent of their level, professional soccer players, need 48 hours to recover after an official match. Professionals gain more fatigue than young players after a match, but recover as fast. Thus, they recover more efficiently especially due to a better physical condition and fitness training. It is expected that the results showed in the study help elite soccer and fitness coaches to manage the training load of the team according to the match.

  19. Sport-specific factors predicting player retention in junior cricket.

    Science.gov (United States)

    Talpey, Scott; Croucher, Tom; Bani Mustafa, Ahmed; Finch, Caroline F

    2017-04-01

    Understanding factors that motivate young athletes to continue participation in sport can help key stakeholders cultivate an environment that fosters long-term participation. This investigation sought to determine the performance and participation factors that influenced continued participation in junior cricket. Administration-level data were collected each annual season across a seven-year period by a community-level junior cricket association in Australia and analysed to identify the performance and participation-based predictors of player retention. All players were males aged <16 years. Players were categorised according to whether they remained in (or departed from) the association at the end of each playing season. A multivariate logistic regression model with a stepwise variable selection was employed to identify significant independent predictors of player retention. The number of innings batted and overs bowled were significant participation-related contributors to junior cricket player retention. Performance factors such as the number of wickets taken and the number of runs scored also significantly influenced player retention. Finally, team age group, the number of previous seasons played and age were also significant factors in player retention. This demonstrates that sufficient opportunity for children to participate in the game and expression of skills competence are key factors for retention in cricket.

  20. Active tuning of stroke-induced vibrations by tennis players.

    Science.gov (United States)

    Chadefaux, Delphine; Rao, Guillaume; Androuet, Philippe; Berton, Eric; Vigouroux, Laurent

    2017-08-01

    This paper investigates how tennis players control stroke-induced vibration. Its aim is to characterise how a tennis player deals with entering vibration waves or how he/she has the ability to finely adjust them. A specific experimental procedure was designed, based on simultaneously collecting sets of kinematic, vibration and electromyographic data during forehand strokes using various commercial rackets and stroke intensities. Using 14 expert players, a wide range of excitations at spectral and temporal levels were investigated. Energetic and spectral descriptors of stroke-induced vibration occurring at the racket handle and at the player's wrist and elbow were computed. Results indicated that vibrational characteristics are strongly governed by grip force and to a lower extent by the racket properties. Grip force management drives the amount of energy, as well as its distribution, into the forearm. Furthermore, hand-grip can be assimilated to an adaptive filter which can significantly modify the spectral parameters propagating into the player's upper limb. A significant outcome is that these spectral characteristics are as much dependent on the player as on the racket. This contribution opens up new perspectives in equipment manufacture by underlining the need to account for player/racket interaction in the design process.

  1. A Novel Music Player Controlling Design Based on Gesture Recognition

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    Yi Liu

    2014-01-01

    Full Text Available This study has proposed a novel music player controlling method based on gesture recognition, which translating the gesture interacting signal into a controlling instruction for the music player. Firstly, utilizing the laptop’s webcam to capture the image information, and then employing the image processing method to tackle it. The skin color detection was used to obtain the information of gesture candidates, and a background subtraction was introduced to eliminate the distributing information. Moreover, in order to ensure the rapid and effective implementation of music player proposed here, the barycenter of a gesture was calculated as one Recognized Reference Information (RRI; a ratio between the gesture’s width and height was also selected as the other RRI; the comparison of these two RRI values was utilized to obtain a pattern signal of the gesture which was corresponding to the controlling instruction for the Music Player. Eventually, a Music Player was programmed and the pattern signal generated by gesture recognition was used to control the Music Player as willing to realize four basic functions: “play”, “pause”, “previous” and “next”. A series of tests using our gesture recognition based Music Player was conducted under the condition with different kinds of complex backgrounds, and the results showed the satisfactory performance of our interactive designing.

  2. Physical performance of elite and subelite Spanish female futsal players

    Science.gov (United States)

    Rubio-Arias, JA; Carrasco-Poyatos, M; Alcaraz, PE

    2016-01-01

    The aim of this study was to determine the parameters distinguishing top female futsal players from lower level players. Twenty-seven female futsal players participated in the study, composed of professional first division (elite; n = 15) players and semi-professional second division players (sub-elite; n = 14). Active and passive straight leg raise tests, isokinetic strength of the knee extensor and flexor muscles at 60° · s-1 angular velocity, squat and counter movement jumps, 30 m sprint, 30 m agility, repeated sprint ability test and maximum ball speed during shooting were measured. The elite players were more agile and kicked harder than sub-elite players in maximum ball speed during the shooting test (P ≤ 0.05). However, no significant differences between teams were observed in active and passive hamstring flexibility, jumping ability, repeated sprint ability test, 30 m sprint time, H/Q ratio and absolute and relative torque from 60° · s-1 angular velocity. Based on these findings we conclude that agility and maximum ball speed during shooting may be important determinant factors of Spanish female futsal actions and could distinguish ability at high-level games. PMID:27601786

  3. Physical performance of elite and subelite Spanish female futsal players

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    DJ Ramos-Campo

    2016-08-01

    Full Text Available The aim of this study was to determine the parameters distinguishing top female futsal players from lower level players. Twenty-seven female futsal players participated in the study, composed of professional first division (elite; n=15 players and semi-professional second division players (sub-elite; n=14. Active and passive straight leg raise tests, isokinetic strength of the knee extensor and flexor muscles at 60º • s-1 angular velocity, squat and counter movement jumps, 30 m sprint, 30 m agility, repeated sprint ability test and maximum ball speed during shooting were measured. The elite players were more agile and kicked harder than sub-elite players in maximum ball speed during the shooting test (P≤0.05. However, no significant differences between teams were observed in active and passive hamstring flexibility, jumping ability, repeated sprint ability test, 30 m sprint time, H/Q ratio and absolute and relative torque from 60° • s-1 angular velocity. Based on these findings we conclude that agility and maximum ball speed during shooting may be important determinant factors of Spanish female futsal actions and could distinguish ability at high-level games.

  4. Throwing speed and accuracy in baseball and cricket players.

    Science.gov (United States)

    Freeston, Jonathan; Rooney, Kieron

    2014-06-01

    Throwing speed and accuracy are both critical to sports performance but cannot be optimized simultaneously. This speed-accuracy trade-off (SATO) is evident across a number of throwing groups but remains poorly understood. The goal was to describe the SATO in baseball and cricket players and determine the speed that optimizes accuracy. 20 grade-level baseball and cricket players performed 10 throws at 80% and 100% of maximal throwing speed (MTS) toward a cricket stump. Baseball players then performed a further 10 throws at 70%, 80%, 90%, and 100% of MTS toward a circular target. Baseball players threw faster with greater accuracy than cricket players at both speeds. Both groups demonstrated a significant SATO as vertical error increased with increases in speed; the trade-off was worse for cricketers than baseball players. Accuracy was optimized at 70% of MTS for baseballers. Throwing athletes should decrease speed when accuracy is critical. Cricket players could adopt baseball-training practices to improve throwing performance.

  5. Tracking of Ball and Players in Beach Volleyball Videos

    Science.gov (United States)

    Gomez, Gabriel; Herrera López, Patricia; Link, Daniel; Eskofier, Bjoern

    2014-01-01

    This paper presents methods for the determination of players' positions and contact time points by tracking the players and the ball in beach volleyball videos. Two player tracking methods are compared, a classical particle filter and a rigid grid integral histogram tracker. Due to mutual occlusion of the players and the camera perspective, results are best for the front players, with 74,6% and 82,6% of correctly tracked frames for the particle method and the integral histogram method, respectively. Results suggest an improved robustness against player confusion between different particle sets when tracking with a rigid grid approach. Faster processing and less player confusions make this method superior to the classical particle filter. Two different ball tracking methods are used that detect ball candidates from movement difference images using a background subtraction algorithm. Ball trajectories are estimated and interpolated from parabolic flight equations. The tracking accuracy of the ball is 54,2% for the trajectory growth method and 42,1% for the Hough line detection method. Tracking results of over 90% from the literature could not be confirmed. Ball contact frames were estimated from parabolic trajectory intersection, resulting in 48,9% of correctly estimated ball contact points. PMID:25426936

  6. SUPERSTITIOUS BEHAVIOR AMONG JUDO, TAEKWONDO AND BOXING PLAYERS

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    Gaurav Dureja

    2016-04-01

    Full Text Available Purpose: The present study was designed to measure superstitious behavior among Judo, Taekwondo and Boxing players. Material: Thirty (N=30 male inter-college level players with the age group of 19-25 years were selected through purposive sampling technique to act as subjects from affiliated colleges of Panjab University, Chandigarh. They were further divided into three groups: Group-A [Judo (n=10], Group-B [Taekwondo (n=10] and Group-C [Boxing (n=10]. One Way Analysis of Variance (ANOVA was applied to find out the differences among judo, taekwondo and boxing players. Where ‘F’ values found significant, Least Significant Differences (LSD Post-hoc test was applied to find out the direction and degree of difference. Results: The level of significance was set at 0.05. The result revealed significant differences among judo, taekwondo and boxing players on the sub parameters: clothing and appearance, preparation, team ritual and coach. However, no significant differences have been observed on the sub-parameters fetish, game/competition, prayer and parameter superstitious (Total. Conclusions: The obtained results showed significant differences on the sub-parameter Coach among Judo, Taekwondo and Boxing players. While calculating the mean values of entire groups, it has been observed that Boxing players demonstrate significantly better on the sub-parameter Coach. Therefore, it can be ascertained that Boxing players are more confident that coach bring a lucky charm to our game.

  7. Somatotype, size and body composition of competitive female volleyball players.

    Science.gov (United States)

    Malousaris, Grigoris G; Bergeles, Nikolaos K; Barzouka, Karolina G; Bayios, Ioannis A; Nassis, George P; Koskolou, Maria D

    2008-06-01

    The aim of this study was to describe the morphological characteristics of competitive female volleyball players. For this purpose, body weight and height, breadths and girths as well as skinfold thickness at various body sites were assessed in 163 elite female volleyball players (age: 23.8+/-4.7 years, years of playing: 11.5+/-4.2, hours of training per week: 11.9+/-2.9, means+/-S.D.). Seventy-nine of these players were from the A1 division and the rest from the A2 division of the Greek National League. Two-way ANOVA was used to compare the differences in these characteristics between competition level and playing position. Body height ranged from 161cm to 194cm, and the mean value (177.1+/-6.5cm) was not inferior to that of international players of similar calibre. Adiposity of these players (sum of 5 skinfolds: 51.8+/-10.2mm, percent body fat: 23.4+/-2.8) was higher than that reported in other studies in which, however, different methodology was used. Volleyball athletes of this study were mainly balanced endomorphs (3.4-2.7-2.9). The A1 division players were taller and slightly leaner with greater fat-free mass than their A2 counterparts. Significant differences were found among athletes of different playing positions which are interpreted by their varying roles and physical demands during a volleyball game. The volleyball players who play as opposites were the only subgroup of players differing between divisions; the A2 opposites had more body fat than A1 opposites. These data could be added in the international literature related to the anthropometric characteristics of competitive female volleyball players.

  8. Performance Outcomes After Metacarpal Fractures in National Basketball Association Players.

    Science.gov (United States)

    Guss, Michael S; Begly, John P; Ramme, Austin J; Hinds, Richard M; Karia, Raj J; Capo, John T

    2016-12-01

    Background: The aim was to determine whether players in the National Basketball Association (NBA) who sustain metacarpal fractures demonstrate decreased performance upon return to competition when compared with their performance before injury and that of their control-matched peers. Methods: Data for 32 NBA players with metacarpal fractures incurred over 11 seasons (2002-2003 to 2012-2013) were obtained from injury reports, press releases, and player profiles (www.nba.com and www.basketballreference.com). Player age, body mass index (BMI), position, shooting hand, number of years in the league, and treatment (surgical vs nonsurgical) were recorded. Individual season statistics for the 2 seasons immediately prior to injury and the 2 seasons after injury, including player efficiency rating (PER), were obtained. Thirty-two controls matched by player position, age, and performance statistics were identified. A performance comparison of the cohorts was performed. Results: Mean age at the time of injury was 27 years with an average player BMI of 24. Players had a mean 5.6 seasons of NBA experience prior to injury. There was no significant change in PER when preinjury and postinjury performances were compared. Neither injury to their shooting hand nor operative management of the fracture led to a decrease in performance during the 2 seasons after injury. When compared with matched controls, no significant decline in performance in PER the first season and second season after injury was found. Conclusion: NBA players sustaining metacarpal fractures can reasonably expect to return to their preinjury performance levels following appropriate treatment.

  9. A Profile of Fitness Parameters and Performance of Volleyball Players

    Directory of Open Access Journals (Sweden)

    Govind B. Taware

    2013-07-01

    Full Text Available Background: Ball games require comprehen-sive ability including physical, technical, men-tal and tactical abilities. Among them, physicalabilities of players exert marked effects on theskill of the players themselves and the tacticsof the team. Therefore players must have thephysical abilities to meet the demand of thesport. Volleyball is one of the most popularlyplayed games in the world. Unfortunately, thelevel of performance of the Indian volleyballplayers lags far behind the international stan-dards. Aim of the Study: The present study wasaimed to assess flexibility, muscular endurance,power and cardio-respiratory endurance of vol-leyball players and to compare the results withage matched controls. Also, to compare thefindings of the volleyball players with that ofthe international norms from the available lit-erature and to make some suggestions for theimprovement in their performance level. Ma-terial and Methods: The study was carried outin 40 male volleyball players aged between 17to 26 years and 40 ages matched male controls.Physical fitness parameters namely flexibility,muscular endurance, power and cardio-respi-ratory endurance were measured, data was ana-lyzed using unpaired ‘t’-test. Results: It was ob-served that all physical fitness parameters weresignificantly more in players as compared totheir aged-matched controls but when values ofthe subjects were compared to internationalstandards; our subjects were behind the recom-mended norms for the elite volleyball players.Conclusion: The volleyball players have moreadvantage of flexibility muscular endurance,power and cardio-respiratory endurance.

  10. Management of female handball players' activity applying interactive technologies

    Directory of Open Access Journals (Sweden)

    Frolova L.S.

    2012-04-01

    Full Text Available The efficiency of developed methods for the control of female handball players' readiness to competitive activity was determined. The opportunities of team management regarding the specification of playing role, the formation of the starting line of players and the replacement according to game priorities in attack or defense were considered. The availability of the adequate zone of handball players' mobilizing readiness that allows to have a significant influence on individual effectiveness in the conditions of optimal management and to increase the quality of team game was determined.

  11. Design of a WAV audio player based on K20

    Directory of Open Access Journals (Sweden)

    Xu Yu

    2016-01-01

    Full Text Available The designed player uses the Freescale Company’s MK20DX128VLH7 as the core control ship, and its hardware platform is equipped with VS1003 audio decoder, OLED display interface, USB interface and SD card slot. The player uses the open source embedded real-time operating system μC/OS-II, Freescale USB Stack V4.1.1 and FATFS, and a graphical user interface is developed to improve the user experience based on CGUI. In general, the designed WAV audio player has a strong applicability and a good practical value.

  12. Vitamin D profile in National Football League players.

    Science.gov (United States)

    Maroon, Joseph C; Mathyssek, Christina M; Bost, Jeffrey W; Amos, Austin; Winkelman, Robert; Yates, Anthony P; Duca, Mark A; Norwig, John A

    2015-05-01

    By maintaining phosphate and calcium homeostasis, vitamin D is critical for bone health and possibly physical performance. Hence, vitamin D is important to athletes. Few studies have investigated vitamin D levels in relation to fractures and performance in athletes, and no published study has included a multiracial sample of professional American football players. To assess vitamin D levels, including the prevalence of vitamin D deficiency/insufficiency, in professional American football players and to evaluate the association of vitamin D levels with race, fracture history, and the ability to obtain a contract position, which may be a marker for athletic performance. Cohort study; Level of evidence, 3. Serum vitamin D levels of 80 professional football players from a single team in the National Football League were obtained during the 2011 off-season (mean age, 26.5±3.7 years; black, n=67 [84%]). These levels were used to compare injury reports from the 2011-2012 and 2012-2013 seasons. Statistical analyses were performed to test if vitamin D levels were related to race, fracture history, and the ability to obtain a contract position. Mean vitamin D level was 27.4±11.7 ng/mL, with significantly lower levels for black players (25.6±11.3 ng/mL) versus white players (37.4±8.6 ng/mL; F 1,78=13.00, P=.001). All athletes who were vitamin D deficient were black. When controlling for number of professional years played, vitamin D levels were significantly lower in players with at least 1 bone fracture when compared with no fractures. Players who were released during the preseason because of either injury or poor performance had significantly lower vitamin D levels than did players who played in the regular season. Black professional football players have a higher rate of vitamin D deficiency than do white players. Furthermore, professional football players with higher vitamin D levels were more likely to obtain a contract position in the National Football League

  13. Particle Swarm Optimization of Electricity Market Negotiating Players Portfolio

    DEFF Research Database (Denmark)

    Pinto, Tiago; Vale, Zita; Sousa, Tiago

    2014-01-01

    for market players. The ALBidS system allows MASCEM market negotiating players to take the best possible advantages from each market context. However, it is still necessary to adequately optimize the players’ portfolio investment. For this purpose, this paper proposes a market portfolio optimization method......, based on particle swarm optimization, which provides the best investment profile for a market player, considering different market opportunities (bilateral negotiation, market sessions, and operation in different markets) and the negotiation context such as the peak and off-peak periods of the day...

  14. Cryptographically Blinded Games: Leveraging Players' Limitations for Equilibria and Profit

    DEFF Research Database (Denmark)

    Hubacek, Pavel; Park, Sunoo

    2014-01-01

    In this work we apply methods from cryptography to enable mutually distrusting players to implement broad classes of mediated equilibria of strategic games without trusted mediation. Our implementation uses a pre-play 'cheap talk' phase, consisting of non- binding communication between players pr...... prior to play in the original game. In the cheap talk phase, the players run a secure multi-party computation protocol to sample from an equilibrium of a "cryptographically blinded" version of the game, in which actions are encrypted...

  15. Thermoregulation, Fluid Balance, and Sweat Losses in American Football Players.

    Science.gov (United States)

    Davis, Jon K; Baker, Lindsay B; Barnes, Kelly; Ungaro, Corey; Stofan, John

    2016-10-01

    Numerous studies have reported on the thermoregulation and hydration challenges athletes face in team and individual sports during exercise in the heat. Comparatively less research, however, has been conducted on the American Football player. Therefore, the purpose of this article is to review data collected in laboratory and field studies and discuss the thermoregulation, fluid balance, and sweat losses of American Football players. American Football presents a unique challenge to thermoregulation compared with other sports because of the encapsulating nature of the required protective equipment, large body size of players, and preseason practice occurring during the hottest time of year. Epidemiological studies report disproportionately higher rates of exertional heat illness and heat stroke in American Football compared with other sports. Specifically, larger players (e.g., linemen) are at increased risk for heat ailments compared with smaller players (e.g., backs) because of greater body mass index, increased body fat, lower surface area to body mass ratio, lower aerobic capacity, and the stationary nature of the position, which can reduce heat dissipation. A consistent finding across studies is that larger players exhibit higher sweating rates than smaller players. Mean sweating rates from 1.0 to 2.9 L/h have been reported for college and professional American Football players, with several studies reporting 3.0 L/h or more in some larger players. Sweat sodium concentration of American Football players does not seem to differ from that of athletes in other sports; however, given the high volume of sweat loss, the potential for sodium loss is higher in American Football than in other sports. Despite high sweating rates with American Football players, the observed disturbances in fluid balance have generally been mild (mean body mass loss ≤2 %). The majority of field-based studies have been conducted in the northeastern part of the United States, with limited

  16. Generative Agents for Player Decision Modeling in Games

    DEFF Research Database (Denmark)

    Holmgård, Christoffer; Liapis, Antonios; Togelius, Julian

    2014-01-01

    This paper presents a method for modeling player decision making through the use of agents as AI-driven personas. The paper argues that artificial agents, as generative player models, have properties that allow them to be used as psyhometrically valid, abstract simulations of a human player...... to or divergence from these. Essentially, at each step the action of the human is compared to what actions a number of reinforcement-learned agents would have taken in the same situation, where each agent is trained using a different reward scheme. Finally, extensions are outlined for adapting the agents...

  17. Sports players : the heroes of the mediated sacred sphere

    Directory of Open Access Journals (Sweden)

    María del Mar RUBIO-HERNÁNDEZ

    2011-01-01

    Full Text Available Broadcasted sport is one of the elements of the mediated culture which mobilizes extremely passionate masses. Thus, it can be considered as a mythical expression within current society, since contemporary era is witness to the revival of the sacred which manifests through rituals, myths and the divinization of certain products and celebrities. This article analyzes how media depictions exalt players as objects of worship and devotion. It will specifically focus on the most successful Spanish sportsmen such as the tennis player Rafael Nadal and the players of the national soccer team and how they are promoted as national heroes in advertising.

  18. CAREER TRANSITION FROM JUNIOR TO SENIOR IN BASKETBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Alberto Lorenzo

    2009-01-01

    Full Text Available The purpose of the study was to investigate what factors affect basketball players in the transition from junior and amateur to senior and professional sport respectively. The study was a qualitative research which uses a semi-structured interview to get the data. There were interviewed five Spanish basketball players who were starting playing in a team of Basketball Club Association (C.B.A.. The results showed that the participants face several changes both in the sport and in the life outside sport. At the same time, the results indicated the existence of several coping strategies that help the player in his career transition.

  19. Beneficial Long Communication in the Multi-Player Electronic Mail Game

    NARCIS (Netherlands)

    De Jaegher, K.J.M.

    2015-01-01

    In the two-player electronic mail game (EMG), as is well-known, the probability of collective action is lower the more confirmations and re-confirmations are made available to players. In the multi-player EMG, however, as we show players may coordinate on equilibria where they require only few of

  20. Young Football Players Tackle Greatest Concussion Risk At Practice

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_160579.html Young Football Players Tackle Greatest Concussion Risk at Practice But ... Children under the age of 14 who play football are at risk of concussions, and a small ...

  1. Physical profiles of elite male field hockey and soccer players ...

    African Journals Online (AJOL)

    Physical profiles of elite male field hockey and soccer players - application to sport-specific tests. ... South African Journal of Sports Medicine ... of field tests for hockey and soccer for the purposes of talent identification and training prescription.

  2. Intermittent Testing and Training for High-Level Football Players

    DEFF Research Database (Denmark)

    Ingebrigtsen, Jørgen

    Football is the most popular sport in the world, played by over 400 million men and women. In addition to the wide range of sport-specific technical and tactical skills needed, several physical components have been shown to be necessary to perform at a high level. The present PhD thesis is based...... on four articles that focus on physical testing and training for elite and sub-elite football players.The first article (Study I) aims to identify and establish aerobic capacities and anthropometric characteristics of elite female football players with the use of laboratory tests, and to examine whether...... with other field tests the Yo-Yo IR2 has become an important tool for monitoring the physical fitness of football players. However, the burden of testing, for players (physically and mentally) and the coaching staff (time consuming), is large and there is a probability that the tests may contain overlapping...

  3. Comparative Study on Anxiety between Student Players of Different ...

    African Journals Online (AJOL)

    user

    cognitive and behavioral components. The root .... on the induced stress on the heart rate of players before the game and physical work load and ... analysis rather than to assume the relationships based on previous theories per se (Reilly and.

  4. Research on Dietary Nutrition Supplement of Taekwondo Players

    Directory of Open Access Journals (Sweden)

    Shuqun Qu

    2014-10-01

    Full Text Available To comprehend the characteristics of Taekwondo and the problems lying in the nutrient and dietary structure of Taekwondo players through this study and then formulate a scientific and reasonable structure in nutrient and dietary for Taekwondo players, in order to improve their athletic ability in the meantime of improving their physical quality. To comprehend energy consumption characteristics of Taekwondo and current situation of nutrient and dietary structure of Taekwondo players through methods of literature collection and comparative research and then come up with a scientific and reasonable structure in nutrient and dietary. A reasonable nutrient and dietary structure can not only improve physical function and guarantee a normal internal metabolism of Taekwondo players, but also can effectively improve their athletic ability and improve their performance in competition.

  5. Tackle-injury epidemiology in koshuis rugby players at Stellenbosch ...

    African Journals Online (AJOL)

    Little is known about the epidemiology of tackle injuries in koshuis rugby players. Objectives. To (i) calculate ... Department of Sport Science, Stellenbosch University, Stellenbosch, South Africa. Corresponding ..... prevention. Int J Sports Sci ...

  6. Hypoconnectivity and Hyperfrontality in Retired American Football Players

    Science.gov (United States)

    Hampshire, Adam; MacDonald, Alex; Owen, Adrian M.

    2013-10-01

    Recent research has raised concerns about the long-term neurological consequences of repetitive concussive and sub-concussive injuries in professional players of American Football. Despite this interest, the neural and psychological status of retired players remains unknown. Here, we evaluated the performances and brain activation patterns of retired National Football League players (NFL alumni) relative to controls using an fMRI-optimised neuropsychological test of executive function. Behaviourally, the NFL alumni showed only modest performance deficits on the executive task. By contrast, they showed pronounced hyperactivation and hypoconnectivity of the dorsolateral frontal and frontopolar cortices. Critically, abnormal frontal-lobe function was correlated with the number of times that NFL alumni reported having been removed from play after head injury and was evident in individual players. These results support the hypothesis that NFL alumni have a heightened probability of developing executive dysfunction and suggest that fMRI provides the most sensitive biomarker of the underlying neural abnormality.

  7. Soccer players' fitting perception of different upper boot materials.

    Science.gov (United States)

    Olaso Melis, J C; Priego Quesada, J I; Lucas-Cuevas, A G; González García, J C; Puigcerver Palau, S

    2016-07-01

    The present study assessed the influence of upper boot materials on fitting perception. Twenty players tested three soccer boots only differing in the upper boot material (natural calf leather, natural kangaroo leather and synthetic leather). Players reported fitting perception and preference on specific foot areas using a perceived fitting scale. Ratings were averaged for every foot area. Repeated measures ANOVA was used to analyze the differences between boots. The kangaroo leather boots were perceived tighter and closer to the preferred fitting in general fitting, metatarsals area and instep area. The synthetic leather boots were perceived as the loosest and as the most distant boot from the preferred fitting in medial front area and instep area. In conclusion, the type of upper boot material influences the fitting perception of soccer players. The kangaroo leather was the material whose fitting was perceived closest to the players fitting preference.

  8. How Players Lose Interest in Playing a Game

    DEFF Research Database (Denmark)

    Bauckhage, Christian; Kersting, Kristian; Sifa, Rafet

    2012-01-01

    Analyzing telemetry data of player behavior in computer games is a topic of increasing interest for industry and research, alike. When applied to game telemetry data, pattern recognition and statistical analysis provide valuable business intelligence tools for game development. An important problem...... introduce methods from random process theory into game data mining in order to draw inferences about player engagement. Given large samples (over 250,000 players) of behavioral telemetry data from five different action-adventure and shooter games, we extract information as to how long individual players...... have played these games and apply techniques from lifetime analysis to identify common patterns. In all five cases, we find that the Weibull distribution gives a good account of the statistics of total playing times. This implies that an average player’s interest in playing one of the games considered...

  9. Development of speed qualities of skilled water-polo players

    Directory of Open Access Journals (Sweden)

    Ostrovsky M.V.

    2010-02-01

    Full Text Available Swimming preparation of water-polo players is the basic factor of victory of command. There are a few variants of development of speed swimming preparation. The effective pedagogical mean of stimulation of speed qualities is brief exercises at the end of employments after long aerobic work. The purpose of work is an improvement of method of speed preparation of skilled water-polo players. 26 skilled water-polo players (MS -14 and KMS - 12 took part in an experiment in age from 21 to 32 years. The results of correction of structure of training employment are in-process presented in micro cycle. They are directed on the improvement of speed qualities of water-polo players.

  10. Diagnosis Aerobic Component of Operational Preparedness Skill Players

    Directory of Open Access Journals (Sweden)

    Vasylyuk Vasyl

    2017-01-01

    Full Text Available Considerable importance for the control system, selection and orientation of the players on the stage long-term preparation plays a selection of effective methods of testing the various components of functional fitness athlete for timely, objective information about the players. The use of reliable scientific methods of effective monitoring of the athlete contributes to the further improvement of skills, increase athletic achievements. The purpose of this article is to describe and summarize modern methods of diagnosis and development of aerobic component of operational preparedness players qualifications. This article describes methods that actively and effectively used in leading European football teams. Specifically Yo-Yo test, test Shuttle (beep-test, Bangsbo test, test Hoff-Helgerud, test Conconi, Wingate-test. These tests have a high level of reliability and security mechanisms for assessing aerobic power players.

  11. Preferred Leadership Behaviours of Male and Female Badminton Players

    Directory of Open Access Journals (Sweden)

    Rajkumar S HARMA

    2015-06-01

    Full Text Available Pr eferences for specific coaching behaviours of male and female Badminton players were measured by the modified and revised Leadership Scale for Sport. Eighty two (Males=61, Females=21 badminton players were selected from amongst the players representing th eir respective university teams in East - zone Inter - university Badminton (Men/Women tournaments held at Bilaspur (CG. The present investigation noted the statistically significant differences among East - zone Inter - university level male as well as female B adminton player’s preferences for specific coaching behaviour. Differences were not observed between male and female badminton players in all the dimensions together of specific coaching behaviours of preferred leadership. It is recommended that coaches a lign their coaching style to meet the needs of their teams.

  12. A measure for the batting performance of cricket players : research ...

    African Journals Online (AJOL)

    Abstract. A single measure that can be used to assess the performance of batsmen ... a formula for batting performance and a classification table for Test players. Keywords: Batting performance, Consistency, Cricket, Present form of a batsman ...

  13. Real-Time Game Adaptation for Optimizing Player Satisfaction

    DEFF Research Database (Denmark)

    Yannakakis, Georgios; Hallam, John

    2009-01-01

    A methodology for optimizing player satisfaction in games on the "playware" physical interactive platform is demonstrated in this paper. Previously constructed artificial neural network user models, reported in the literature, map individual playing characteristics to reported entertainment...

  14. Extensive monitoring through multiple blood samples in professional soccer players

    DEFF Research Database (Denmark)

    Heisterberg, Mette F; Fahrenkrug, Jan; Krustrup, Peter

    2013-01-01

    ABSTRACT: The aim of this study was to make a comprehensive gathering of consecutive detailed blood samples from professional soccer players, and to analyze different blood parameters in relation to seasonal changes in training and match exposure.Blood samples were collected five times during a six...... months period and analyzed for 37 variables in 27 professional soccer players from the best Danish league. Additionally, players were tested for body composition, VO2max and physical performance by the Yo-Yo intermittent endurance sub-max test (IE2).Multiple variations in blood parameters occurred during...... of the season. Leucocytes decreased with increased physical training. Lymphocytes decreased at the end of the season. VO2max decreased towards the end of the season whereas no significant changes were observed in the IE2 test.The regular blood samples from elite soccer players reveal significant changes...

  15. A characterization of 2-player mechanisms for scheduling

    CERN Document Server

    Christodoulou, George; Vidali, Angelina

    2008-01-01

    We study the mechanism design problem of scheduling unrelated machines and we completely characterize the decisive truthful mechanisms for two players when the domain contains both positive and negative values. We show that the class of truthful mechanisms is very limited: A decisive truthful mechanism partitions the tasks into groups so that the tasks in each group are allocated independently of the other groups. Tasks in a group of size at least two are allocated by an affine minimizer and tasks in singleton groups by a task-independent mechanism. This characterization is about all truthful mechanisms, including those with unbounded approximation ratio. A direct consequence of this approach is that the approximation ratio of mechanisms for two players is 2, even for two tasks. In fact, it follows that for two players, VCG is the unique algorithm with optimal approximation 2. This characterization provides some support that any decisive truthful mechanism (for 3 or more players) partitions the tasks into gro...

  16. Ranking benchmarks of top 100 players in men's professional tennis.

    Science.gov (United States)

    Reid, Machar; Morris, Craig

    2013-01-01

    In men's professional tennis, players aspire to hold the top ranking position. On the way to the top spot, reaching the top 100 can be seen as a significant career milestone. National Federations undertake extensive efforts to assist their players to reach the top 100. However, objective data considering reasonable ranking yardsticks for top 100 success in men's professional tennis are lacking. Therefore, it is difficult for National Federations and those involved in player development to give empirical programming advice to young players. By taking a closer look at the ranking history of professional male tennis players, this article tries to provide those involved in player development a more objective basis for decision-making. The 100 names, countries, birthdates and ranking histories of the top 100 players listed in the Association of Tennis Professionals (ATP) at 31 December 2009 were recorded from websites in the public domain. Descriptive statistics were reported for the ranking milestones of interest. Results confirmed the merits of the International Tennis Federation's junior tour with 91% of the top 100 professionals earning a junior ranking, the mean peak of which was 94.1, s=148.9. On average, top 100 professionals achieved their best junior rankings and earned their first ATP point at similar ages, suggesting that players compete on both the junior and professional tours during their transition. Once professionally ranked, players took an average 4.5, s=2.1 years to reach the ATP top 100 at the mean age of 21.5, s=2.6 years, which contrasts with the mean current age of the top 100 of 26.8, s=3.2. The best professional rankings of players born in 1982 or earlier were positively related to the ages at which players earned their first ATP point and then entered the top 100, suggesting that the ages associated with these ranking milestones may have some forecasting potential. Future work should focus on the change in top 100 demographics over time as well

  17. Upper extremity sensorimotor control among collegiate football players.

    Science.gov (United States)

    Laudner, Kevin G

    2012-03-01

    Injuries stemming from shoulder instability are very common among athletes participating in contact sports, such as football. Previous research has shown that increased laxity negatively affects the function of the sensorimotor system potentially leading to a pathological cycle of shoulder dysfunction. Currently, there are no data detailing such effects among football players. Therefore, the purpose of this study was to examine the differences in upper extremity sensorimotor control among football players compared with that of a control group. Forty-five collegiate football players and 70 male control subjects with no previous experience in contact sports participated. All the subjects had no recent history of upper extremity injury. Each subject performed three 30-second upper extremity balance trials on each arm. The balance trials were conducted in a single-arm push-up position with the test arm in the center of a force platform and the subjects' feet on a labile device. The trials were averaged, and the differences in radial area deviation between groups were analyzed using separate 1-way analyses of variance (p football players showed significantly more radial area deviation of the dominant (0.41 ± 1.23 cm2, p = 0.02) and nondominant arms (0.47 ± 1.63 cm2, p = 0.03) when compared with the control group. These results suggest that football players may have decreased sensorimotor control of the upper extremity compared with individuals with no contact sport experience. The decreased upper extremity sensorimotor control among the football players may be because of the frequent impacts accumulated during football participation. Football players may benefit from exercises that target the sensorimotor system. These findings may also be beneficial in the evaluation and treatment of various upper extremity injuries among football players.

  18. Analysis of the Motor Activities of Professional Polish Soccer Players

    Directory of Open Access Journals (Sweden)

    Andrzejewski Marcin

    2016-12-01

    Full Text Available Introduction. The aims of the present study were to determine the activity profiles of a large sample of Polish Premier League soccer players during elite-standard soccer matches depending on their position on the pitch and the intensity range of physical activity. Material and methods. The study sample comprised 1,178 players in 5 outfield positions: external defenders (ED, n = 289, central defenders (CD, n = 307, central midfield players (CM, n = 327, external midfield players (EM, n = 152, and forwards (F, n = 103. Altogether, 81 Polish League games held during four domestic seasons (2010-2011, 2011-2012, 2012-2013, and 2013-2014 were used in the analysis. A semi-automatic computerised player tracking system (Amisco Pro®, version 1.0.2, Nice, France was applied to create the match activity profiles of the teams. Results. The results of statistical analysis revealed that the average total distance covered by all the players (n = 1,178 was 11,313 ± 852 m. With respect to the players’ position on the pitch, the central midfielders travelled the longest average distance (11,894 ± 765 m during the game. The longest distance was covered in the V1 intensity range (62%, followed by V2 (15%, V3 (10%, V4 (8%, V5 (3%, and V6 (2%. Conclusions. The objective of this study was to verify the differences among playing positions and to quantify the demands placed on elite Polish soccer players in each individual position during match play. While analysing elite-level match play in terms of the overall distance covered in different categories of intensity, we found a number of statistically significant differences between different playing positions. The data presented in this study can be regarded as norms for elite soccer players, serve for present and future comparison, and represent the scientific basis for developing position-specific conditioning/training protocols in soccer.

  19. Biomechanics of heading a soccer ball: implications for player safety.

    Science.gov (United States)

    Babbs, C F

    2001-08-08

    To better understand the risk and safety of heading a soccer ball, the author created a set of simple mathematical models based upon Newton's second law of motion to describe the physics of heading. These models describe the player, the ball, the flight of the ball before impact, the motion of the head and ball during impact, and the effects of all of these upon the intensity and the duration of acceleration of the head. The calculated head accelerations were compared to those during presumably safe daily activities of jumping, dancing, and head nodding and also were related to established criteria for serious head injury from the motor vehicle crash literature. The results suggest heading is usually safe but occasionally dangerous, depending on key characteristics of both the player and the ball. Safety is greatly improved when players head the ball with greater effective body mass, which is determined by a player"s size, strength, and technique. Smaller youth players, because of their lesser body mass, are more at risk of potentially dangerous headers than are adults, even when using current youth size balls. Lower ball inflation pressure reduces risk of dangerous head accelerations. Lower pressure balls also have greater "touch" and "playability", measured in terms of contact time and contact area between foot and ball during a kick. Focus on teaching proper technique, the re-design of age-appropriate balls for young players with reduced weight and inflation pressure, and avoidance of head contact with fast, rising balls kicked at close range can substantially reduce risk of subtle brain injury in players who head soccer balls.

  20. Implementation of Mobile Streaming Media Player Based on BREW

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-rong; LIU Zhao

    2006-01-01

    Nowadays mobile streaming service through cell phone is becoming the highlight of new value-added mobile services. Based on the present CDMA1x wireless data network and Binary Runtime Environment for Wireless (BREW) platform, adopting compression technologies of H.264 and QCP, a set of streaming media players are designed and implemented, and the principle, structure, key technologies and performance analysis of this system are introduced. This player works well in practice.

  1. The strategy of players on the European gas market

    Energy Technology Data Exchange (ETDEWEB)

    Lecarpentier, A

    2006-07-01

    One result of opening up the European gas market to competition has been to increase the number and diversity of the players involved, whether producers, suppliers or electric utilities. However, while the gas on offer is still controlled by a handful of market players given the increasing importance of state-owned companies from exporting countries outside Europe, the downstream gas sector continues to show a strong concentration of incumbent operators seeking a dominant position in the supply of gas. (author)

  2. An Analysis of Futsal Players' Self-Esteem Levels

    Science.gov (United States)

    Kocak, Mehmet

    2015-01-01

    The purpose of this study is to investigate the self-esteem levels of futsal players according to certain variables. The samples of the study constituted 119 females and 96 males; a total of 215 players with an average age of 21.57 ± 2.20 years. The research was carried out with the end of "Rosenberg self-esteem Scale" developed by…

  3. EMOTIONAL INTELLIGENCE AMONG FEMALE BASEBALL PLAYERS: A PSYCHOLOGICAL PROBE

    Directory of Open Access Journals (Sweden)

    Dalwinder Singh

    2015-09-01

    Full Text Available Purpose : The present study was conducted to determine the emotional intelligence among Indian female baseball players. Material : For the purpose of present study, two hundred (N=200 senior national female baseball players were selected through purposive sampling technique from different regions of India. They were selected from four different regions: A (North region baseball players=50, B (East region baseball players=50, C (West region baseball players=50 and D (South region baseball players=50. To collect the required data for the present study, the questionnaire developed by Hyde et al. (2001 on emotional intelligence was administered. One Way Analysis of Variance (ANOVA was employed to compare the entire regions. Where ‘F’ values were found significant, LSD (Least Significant Difference Post-hoc test was applied to find out the direction and degree of difference. The level of significance was set at 0.05. Results : Significant differences were observed among North, East, West and South regions female baseball players on the sub-parameters; empathy, self-development, value orientation and on the parameter Emotional Intelligence (Total. No significant differences were noticed on the sub-parameters; self-awareness, self-motivation, emotional stability, managing relations, integrity, commitment and altruistic behaviour. Conclusion: The outcome of results might be due to the fact that East region female baseball players are able to pay attention to the worries and concerns of others, can listen to someone without the urge to say something, can stay focused under pressure, are able to handle multiple demands and able to identify and separate their emotions.

  4. A Musculoskeletal Profile of Elite Female Soccer Players

    OpenAIRE

    Chiaia, Theresa A.; Maschi, Robert A.; Stuhr, Robyn M.; Rogers, Jennifer R.; Sheridan, Monique A.; Callahan, Lisa R.; Hannafin, Jo A.

    2009-01-01

    The purpose of this study is to identify lower-extremity (LE) musculoskeletal characteristics of elite female soccer players and to determine whether differences between dominant and nondominant extremities exist with respect to strength, flexibility, and range of motion. Physical data were collected from 26 female professional soccer players. Core control, hip and knee passive range of motion (PROM), LE flexibility, hip abductor strength, and dynamic functional alignment were assessed for ea...

  5. An Analysis of Futsal Players' Self-Esteem Levels

    Science.gov (United States)

    Kocak, Mehmet

    2015-01-01

    The purpose of this study is to investigate the self-esteem levels of futsal players according to certain variables. The samples of the study constituted 119 females and 96 males; a total of 215 players with an average age of 21.57 ± 2.20 years. The research was carried out with the end of "Rosenberg self-esteem Scale" developed by…

  6. Analyzing online game players: from materialism and motivation to attitude.

    Science.gov (United States)

    Chang, Ju-Hui; Zhang, Hongxia

    2008-12-01

    The online game market has been growing rapidly and has received an increasing amount of attention in recent years. The results of a survey conducted in China to explore online game players' attitude formation reveal that (a) the online game player's level of materialism positively influences the motivation for playing, (b) motivation positively influences attitude toward online games, and (c) motivation fully mediates the effects of materialism on attitude.

  7. Return to Sport and Performance After Microfracture in the Knees of National Basketball Association Players

    OpenAIRE

    Harris, Joshua D.; David M. Walton; Erickson, Brandon J.; Verma, Nikhil N.; Abrams, Geoffrey D.; Bush-Joseph, Charles A.; Bach, Bernard R.; Cole, Brian J.

    2013-01-01

    Background: Use of microfracture in the knees of National Basketball Association (NBA) players is controversial. Hypotheses: (1) There would be a high rate of return to sport (RTS) in NBA players following microfracture, (2) players would RTS the season following surgery, (3) preoperative player performance would not be significantly different on RTS, and (4) there would be no significant difference in RTS rate or postoperative performance in players undergoing microfracture in comparison wit...

  8. Quantitative evaluation of trunk muscle strength in wheelchair basketball players

    Directory of Open Access Journals (Sweden)

    Sileno da Silva Santos

    2016-06-01

    Full Text Available Abstract Trunk muscle strength affects trunk controlling playing an important role in performance and to define the classes of wheelchair basketball players. Trunk control capacity differs among players and quantitative assessments of trunk muscle strength have not been investigated. The aim of this study was to identify and correlate quantitative measures of trunk muscle strength with the wheelchair basketball players' classification. Forty-two male wheelchair basketball players with spinal cord injury, amputation, post-poliomyelitis sequelae, and cerebral palsy had their trunk extension and flexion strength evaluated with isokinetic dynamometer. The classes 1.0, 2.0, 3.0, and 4.0 were considered for statistical analysis. Comparison of trunk muscle strength differed significantly between classes: 1.0 and 3.0; 1.0 and 4.0; 2.0 and 3.0; and 2.0 and 4.0. High correlation was found between the trunk muscle strength and players' classes. The findings of the present study showed a strong correlation of trunk muscle strength and wheelchair basketball classes being able to distinguish players in their classes. However, this quantitative method of evaluation of the trunk muscle strength cannot be solely used to make a decision on the full trunk control.

  9. N-player quantum games in an EPR setting

    CERN Document Server

    Chappell, James M; Abbott, Derek

    2012-01-01

    The $N$-player quantum game is analyzed in the context of an Einstein-Podolsky-Rosen (EPR) experiment. In this setting, a player's strategies are not unitary transformations as in alternate quantum game-theoretic frameworks, but a classical choice between two directions along which spin or polarization measurements are made. The players' strategies thus remain identical to their strategies in the mixed-strategy version of the classical game. In the EPR setting the quantum game reduces itself to the corresponding classical game when the shared quantum state reaches zero entanglement. We find the relations for the probability distribution for $N$-qubit GHZ and W-type states, subject to general measurement directions, from which the expressions for the mixed Nash equilibrium and the payoffs are determined. Players' payoffs are then defined with linear functions so that common two-player games can be easily extended to the $N$-player case and permit analytic expressions for the Nash equilibrium. As a specific exa...

  10. Cavum Septum Pellucidum in Retired American Pro-Football Players.

    Science.gov (United States)

    Gardner, Raquel C; Hess, Christopher P; Brus-Ramer, Marcel; Possin, Katherine L; Cohn-Sheehy, Brendan I; Kramer, Joel H; Berger, Mitchel S; Yaffe, Kristine; Miller, Bruce; Rabinovici, Gil D

    2016-01-01

    Previous studies report that cavum septum pellucidum (CSP) is frequent among athletes with a history of repeated traumatic brain injury (TBI), such as boxers. Few studies of CSP in athletes, however, have assessed detailed features of the septum pellucidum in a case-control fashion. This is important because prevalence of CSP in the general population varies widely (2% to 85%) between studies. Further, rates of CSP among American pro-football players have not been described previously. We sought to characterize MRI features of the septum pellucidum in a series of retired pro-football players with a history of repeated concussive/subconcussive head traumas compared with controls. We retrospectively assessed retired American pro-football players presenting to our memory clinic with cognitive/behavioral symptoms in whom structural MRI was available with slice thickness ≤2 mm (n=17). Each player was matched to a memory clinic control patient with no history of TBI. Scans were interpreted by raters blinded to clinical information and TBI/football history, who measured CSP grade (0-absent, 1-equivocal, 2-mild, 3-moderate, 4-severe) and length according to a standard protocol. Sixteen of 17 (94%) players had a CSP graded ≥2 compared with 3 of 17 (18%) controls. CSP was significantly higher grade (pfootball players compared with patients without a history of TBI.

  11. Risk Factors for Injuries in Professional Football Players.

    Science.gov (United States)

    Haxhiu, Bekim; Murtezani, Ardiana; Zahiti, Bedri; Shalaj, Ismet; Sllamniku, Sabit

    2015-01-01

    The aim of this study was to identify risk factors related to the occurrence of injuries in football players. The study included 216 football players from 12 teams in the elite football league. Football-related injury data were collected prospectively during the 2012/2013 competitive season. At baseline the following information was collected for the players: anthropometric measurements (weight, height, BMI, subcutaneous skinfolds), playing experience, injury history, physical fitness performance test (agility run), peak oxygen uptake. The incidence, type and severity of injuries and training and game exposure times were prospectively documented for each player. Most of the players (n = 155, 71.7%) sustained the injures during the study period. The overall injury incidence during the regular season was 6.3 injuries per 1000 athlete-exposures (95% confidence interval, 4.31-9.67). Multivariate logistic regression analysis showed that playing experience (odds ratio [OR] = 0.44; 95% CI = 0.32-0.61, p football for more than 1 month, with knee injuries (25.42%) being the most severe type. The risk factors that increase injury rates in football players were previous injury, higher age and years of playing. Future research should include adequate rehabilitation program to reduce the risk of injuries.

  12. Early-onset arthritis in retired National Football League players.

    Science.gov (United States)

    Golightly, Yvonne M; Marshall, Stephen W; Callahan, Leigh F; Guskiewicz, Kevin

    2009-09-01

    Injury has been identified as a potential risk factor for osteoarthritis. However, no previous study has addressed playing-career injuries and subsequent osteoarthritis in a large sample of former athletes. The purpose of this study was to describe the prevalence and determinants of arthritis and osteoarthritis in retired professional football players. Self-reported arthritis prevalence and retrospectively-recalled injury history were examined in a cross-sectional survey of 2,538 retired football players. Football players reported a high incidence of injury from their professional playing days (52.8% reported knee injuries, 74.1% reported ligament/tendon injuries, and 14.2% reported anterior cruciate ligament tears). For those under 60 years, 40.6% of retired NFL players reported arthritis, compared with 11.7% of U.S. males (prevalence ratio = 3.5, 95% CI: 3.3 to 3.7). Within the retired NFL player cohort, osteoarthritis was more prevalent in those with a history of knee injury (prevalence ratio = 1.7, 95% CI: 1.5 to 1.9) and ligament/tendon injury (prevalence ratio = 1.6, 95% CI: 1.4 to 1.9). In males under the age of 60, arthritis is over 3 times more prevalent in retired NFL players than in the general U.S. population. This excess of early-onset arthritis may be due to the high incidence of injury in football.

  13. [Eating habits of a group of professional volleyball players].

    Science.gov (United States)

    Gacek, Maria

    2011-01-01

    The aim of the research was an analysis of the eating habits of professional volleyball players according to their sex and age. The research has been carried out on a group of 210 men players and women players at the age of 13-25, representatives of sports clubs in Ostrołeka, Myślenice, Bydgoszcz and Warszawa. The research has revealed a limited realisation of rational diets by both men and women players. The most common mistakes made by them include a smaller number of meals during the day than recommended (especially among men), taking up training on empty stomach and insufficient frequency of consumption of dairy products, fish, vegetables and fruit. The research has also revealed excessive consumption of sweets, sweet sparkling drinks and fast food (mainly among men). The examined players to some extent only apply regular strategies of rehydration of their organisms. A high percentage of them do not pay attention to supplementation of liquids after an effort or they drink a lot of liquids at one time. The most frequently chosen drinks were mineral water and isotonic drinks. Supplementation was applied by a small percentage of the players, mainly men, who most often chose vitamins, Izostar, creatine, L-carnitine and HMB.

  14. Caffeine supplementation and reactive agility in elite youth soccer players.

    Science.gov (United States)

    Jordan, J Bradley; Korgaokar, Ajit; Farley, Richard S; Coons, John M; Caputo, Jennifer L

    2014-05-01

    This study examined the effects of caffeine supplementation (6 mg·kg-1) on performance of a reactive agility test (RAT) in 17 elite, male, youth (M = 14 y) soccer players. Using a double-blind, repeated-measures design, players completed 4 days of testing on the RAT after a standardized warm-up. On day 1, anthropometric measurements were taken and players were accommodated to the RAT. On day 2, baseline performance was established. Caffeine or placebo conditions were randomly assigned on day 3 and the condition was reversed on day 4. Players completed 3 randomized trials of the RAT on days 2, 3, and 4 with at least 1 trial to the players' dominant and nondominant sides. There were no significant differences among conditions in reaction time (RT) to the dominant side, heart rates at any point of measurement, or ratings of perceived exertion (RPE) after completion of the warm-up. Caffeine produced faster RT to the nondominant side (P = .041) and higher RPE at the conclusion of the RAT (P = .013). The effect on the total time (TT) to complete the agility test to the nondominant side approached significance (P = .051). Sprint time and TT to either side did not differ. Caffeine supplementation may provide ergogenic benefit to elite, male, youth soccer players.

  15. ANTROPOMETRIC CHARACTERISTICS AND MOTOR SKILLS OF YOUNG MONTENEGRO BASKETBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Milovan Ljubojević

    2012-09-01

    Full Text Available Testing and measurement in basketball is basically supposed to help in the initial evaluation and interpretation of features and capabilities of players that are important for their activity. The main objective of testing is the possibility of obtaining information about the three general indicators in basketball practice, namely: the level of current results in certain ability, the pace of results improvement in the ability and stability of the results in tests of ability. For this purpose, testing and measurement of young basketball players, members of the Montenegro under-18 team, was carried out. The aim of this paper is to present the basic features and capabilities of young basketball players of Montenegro and their comparison with some other teams. Variables from anthropometry space were measured: body height, arm span, reach height, body mass. Motor skills were observed by variables: the last squat, thrust from a flat bench, rear thrust, lying-sitting for 30 seconds, sargent test, long jump, 20 yard test, kamikaze, špagat, sitting bow. Based on the processed results it can be concluded that the motor skills of our young players, tested in this study, are at the level of the young players of other representations. The results will be of great help to coaches who work with these players.

  16. ARM 7 BASED MP3 PLAYER

    Directory of Open Access Journals (Sweden)

    Ashiq V Mehta

    2014-02-01

    Full Text Available MP3 is a patented encoding format for digital audio which uses a form of lossy data compression. It is a common audio format for consumer audio streaming or storage, as well as a de facto standard of digital audio compression for the transfer and playback of music on most digital audio players. Since the MPEG-1 Layer III encoding technology is nowadays widely used it might be interesting to gain knowledge of how this powerful compression/decompression scheme actually functions. The MPEG-1 Layer III is capable of reducing the bit rate with a factor of 12 without almost any audible degradation. Arm7 lpc2148 is arm7tdmi-s core board microcontroller that uses 16/32-bit 64 pin (lqfp microcontroller no.lpc2148 from Philips (nxp.The hardware system of lpc2148 includes the necessary devices within only one mcu has such as usb, adc, dac, timer/counter, pwm, capture, i2c, spi, uart, and etc.

  17. Unexpected cellular players in Rett syndrome pathology.

    Science.gov (United States)

    Cronk, James C; Derecki, Noel C; Litvak, Vladimir; Kipnis, Jonathan

    2016-08-01

    Rett syndrome is a devastating neurodevelopmental disorder, primarily caused by mutations of methyl CpG-binding protein 2 (MeCP2). Although the genetic cause of disease was identified over a decade ago, a significant gap still remains in both our clinical and scientific understanding of its pathogenesis. Neurons are known to be primary players in pathology, with their dysfunction being the key in Rett syndrome. While studies in mice have demonstrated a clear causative - and potential therapeutic - role for neurons in Rett syndrome, recent work has suggested that other tissues also contribute significantly to progression of the disease. Indeed, Rett syndrome is known to present with several common peripheral pathologies, such as osteopenia, scoliosis, gastrointestinal problems including nutritional defects, and general growth deficit. Mouse models assessing the potential role of non-neuronal cell types have confirmed both roles in disease and potential therapeutic targets. A new picture is emerging in which neurons both initiate and drive pathology, while dysfunction of other cell types and peripheral tissues exacerbate disease, possibly amplifying further neurologic problems, and ultimately result in a positive feedback loop of progressively worsening symptoms. Here, we review what is known about neuronal and non-neuronal cell types, and discuss how this new, integrative understanding of the disease may allow for additional clinical and scientific pathways for treating and understanding Rett syndrome.

  18. Speckle tracking echocardiographic analysis of left ventricular systolic and diastolic function in young elite rugby players.

    Science.gov (United States)

    Mandigout, Stéphane; Maufrais, Claire; Cornette, Thibault; Alaphilippe, Anne; Daviet, Jean C

    2016-11-01

    Little evidence exists in the literature on the effects of mixed-type training on the left ventricle (LV). This study focused on the effects of training on the morphological and functional characteristics of the left ventricle. This study investigated the effects of training on LV function using Speckle Tracking Imaging (STI) in high-level, young rugby players. This prospective and longitudinal cohort study enrolled ten young controls and 24 young rugby players (13 high-level rugby players; 11 amateur rugby players) were included in the study. Standard Tissue Doppler Imaging Echocardiography and STI were performed in this study before and after the season. LV mass and pulsed wave Doppler inflow recording of the LV, including early and atrial waves, were carried out in 2-3-4 chamber views. We assessed three normal strains, rotation, and torsion in the LV. The main results of this study demonstrated that no differences existed between the three groups in LV functional parameters, the longitudinal circumferential and radial strain indices, and rotation and torsion indices. In the professional group, a significantly higher end-diastolic diameter (Prugby players have normal LV remodeling and normal LV function under resting conditions.

  19. The interaction between the tennis court and the player: how does surface affect leg stiffness?

    Science.gov (United States)

    Maquirriain, Javier

    2013-03-01

    An adequate level of leg stiffness is necessary for an optimal tennis performance and leg stiffness should be adapted to frequently changing surfaces as tennis players usually play on different courts. The aim of this study was to evaluate leg stiffness in competitive tennis players on different court surfaces. Ten healthy competitive tennis players (nine men and one woman; mean age = 17.6 +/- 3.2 years) underwent leg stiffness testing by modeling the vertical ground reaction force using an optical system. Flight time and contact time were determined during hopping on two different tennis court surfaces (clay and acrylic). No significant difference was found in the flight time, contact time, and jump height between the surfaces. No significant difference in leg stiffness was found between the surfaces (18.25 +/- 5.8 and 19.27 +/- 4.9 kN/m for clay and acrylic, respectively; p = 0.28). This study demonstrated that contact time and flight time as well as leg stiffness of tennis players remained unchanged when hopping on two different tennis surfaces. Results of this research provide objective data regarding the tennis-specific loading of the locomotor system and proper mechanical adaptation of the player on different surfaces, which may be useful for testing protocols and planning training programs.

  20. Relationship between core strength and key variables of performance in elite rink hockey players.

    Science.gov (United States)

    Hoppe, M W; Freiwald, J; Baumgart, C; Born, D P; Reed, J L; Sperlich, B

    2015-03-01

    The aim of this study was to test the hypothesis that a significant relationship exists between the level of core strength-endurance and key variables of endurance, strength, power, speed, and agility performance in male elite rink hockey players. Ten male elite rink hockey players of the German national team were tested for 1) time to exhaustion, maximum oxygen uptake, and running economy, 2) one repetition maximum bench press and half squat, 3) counter movement jump height, 4) 5 m, 10 m, and 20 m speed, and 5) 22 m agility. The rink hockey players were also tested for 6) ventral, lateral-left, lateral-right, and dorsal core strength-endurance using concentric-eccentric muscle tests. The level of total and ventral core strength-endurance was very largely correlated with maximum oxygen uptake (r=0.74 and r=0.71, both Pcore strength-endurance and time to exhaustion (r=0.66, P0.05). The findings from this study suggest that the level of core strength-endurance is largely to very largely correlated with key variables of endurance performance, but not significantly with strength, power, speed, or agility indicators in male elite rink hockey players. These findings should be noted by coaches and scientists when testing physical fitness or planning strength and conditioning programs for male elite rink hockey players.

  1. METABOLIC DEMANDS OF MATCH PERFORMANCE IN YOUNG SOCCER PLAYERS

    Directory of Open Access Journals (Sweden)

    Alper Aslan

    2012-03-01

    Full Text Available The aim of the present study was to determine metabolic responses, movement patterns and distance covered at running speeds corresponding to fixed blood lactate concentrations (FBLs in young soccer players during a match play. A further aim of the study was to evaluate the relationships between FBLs, maximal oxygen consumption (VO2max and distance covered during a game. A multistage field test was administered to 32 players to determine FBLs and VO2max. Blood lactate (LA, heart rate (HR and rate of perceived exertion (RPE responses were obtained from 36 players during tournament matches filmed using six fixed cameras. Images were transferred to a computer, for calibration and synchronization. In all players, values for LA and HR were higher and RPE lower during the 1st half compared to the 2nd half of the matches (p < 0.01. Players in forward positions had higher LA levels than defenders, but HR and RPE values were similar between playing positions. Total distance and distance covered in jogging, low-moderate-high intensity running and low intensity sprint were higher during the 1st half (p < 0.01. In the 1st half, players also ran longer distances at FBLs [p<0.01; average running speed at 2mmol·L-1 (FBL2: 3.32 ± 0.31m·s-1 and average running speed at 4mmol·L-1 (FBL4: 3.91 ± 0.25m·s-1]. There was a significant difference between playing positions in distance covered at different running speeds (p < 0.05. However, when distance covered was expressed as FBLs, the players ran similar distances. In addition, relationships between FBLs and total distance covered were significant (r = 0.482 to 0.570; p < 0.01. In conclusion, these findings demonstrated that young soccer players experienced higher internal load during the 1st half of a game compared to the 2nd half. Furthermore, although movement patterns of players differed between playing positions, all players experienced a similar physiological stress throughout the game. Finally, total

  2. Norwegian Football Academy Players-Players Self-Assessed Competence, Perfectionism, Goal Orientations and Motivational Climate

    Directory of Open Access Journals (Sweden)

    Eirik Nerland

    2016-06-01

    Full Text Available Grounded in the theoretical framework of achievement goal theory and perfectionism theory, the purpose of this study was to examine how self-assessed perceived abilities covariance these variables among Norwegian football academy players. 140 adolescent football players participated, representing three football academies. Perceived competence was reported as equivalent to or better than others. Perfectionism scores showed personal standards as the highest of the dimensions of perfectionism, while perceived parental pressure was lowest. In contrast, mean task orientation and perceived mastery climate were higher than ego orientation and perceived performance climate. The correlation analysis showed that perceived competence correlated positively with personal standards. Personal standards correlated positively with the rest of the perfectionism dimensions as well as ego orientation, perceived mastery- and performance climate. Concern over mistakes was positively correlated with ego-orientation. Overall, findings suggested that personal standards correlate with perceived competence, while these variables also relate to other perfectionism dimensions, goal orientations and perceived motivational climate. Therefore, coaches should highlight the importance of high personal standards, as a potentially maladaptive function on talent development.

  3. Violent video game players and non-players differ on facial emotion recognition.

    Science.gov (United States)

    Diaz, Ruth L; Wong, Ulric; Hodgins, David C; Chiu, Carina G; Goghari, Vina M

    2016-01-01

    Violent video game playing has been associated with both positive and negative effects on cognition. We examined whether playing two or more hours of violent video games a day, compared to not playing video games, was associated with a different pattern of recognition of five facial emotions, while controlling for general perceptual and cognitive differences that might also occur. Undergraduate students were categorized as violent video game players (n = 83) or non-gamers (n = 69) and completed a facial recognition task, consisting of an emotion recognition condition and a control condition of gender recognition. Additionally, participants completed questionnaires assessing their video game and media consumption, aggression, and mood. Violent video game players recognized fearful faces both more accurately and quickly and disgusted faces less accurately than non-gamers. Desensitization to violence, constant exposure to fear and anxiety during game playing, and the habituation to unpleasant stimuli, are possible mechanisms that could explain these results. Future research should evaluate the effects of violent video game playing on emotion processing and social cognition more broadly.

  4. Monitoring for overreaching in rugby league players.

    Science.gov (United States)

    Coutts, Aaron J; Reaburn, Peter; Piva, Terrence J; Rowsell, Greg J

    2007-02-01

    The aim of this study was to identify indicators of non-functional overreaching (NFOR) in team sport athletes undertaking intensive training loads. Eighteen semi-professional rugby league players were randomly assigned into two pair matched groups. One group completed 6 weeks of normal training (NT) whilst the other group was deliberately overreached through intensified training (IT). Both groups then completed the same 7-day stepwise training load reduction taper. Multistage fitness test (MSFT) performance, VO2 (max), peak aerobic running velocity (V (max)), maximal heart rate, vertical jump, 10-s cycle sprint performance and body mass were measured pre- and post-training period and following the taper. Hormonal, haematological and immunological parameters were also measured pre-training and following weeks 2, 4 and 6 of training and post-taper. MANOVA for repeated measures with contrast analysis indicated that MSFT performance and VO2 (max) were significantly reduced in the IT group over time and condition, indicating that a state of overreaching was attained. However, the only biochemical measure that was significantly different between the IT and NT group was the glutamine to glutamate (Gln/Glu) ratio even though testosterone, testosterone to cortisol (T/C) ratio, plasma glutamate, and CK activity were significantly changed after training in both groups. Positive endurance and power performance changes were observed post-taper in the IT group confirming NFOR. These changes were associated with increases in the T/C ratio and the Gln/Glu ratio and decreases in plasma glutamate and CK activity. These results indicate that although there was no single reliable biochemical marker of NFOR in these athletes, the Gln/Glu ratio and MSFT test may be useful measures for monitoring responses to IT in team sport athletes.

  5. Prevalent morphometric vertebral fractures in professional male rugby players.

    Directory of Open Access Journals (Sweden)

    Karen Hind

    Full Text Available There is an ongoing concern about the risk of injury to the spine in professional rugby players. The objective of this study was to investigate the prevalence of vertebral fracture using vertebral fracture assessment (VFA dual energy X-ray absorptiometry (DXA imaging in professional male rugby players. Ninety five professional rugby league (n = 52 and union (n = 43 players (n = 95; age 25.9 (SD 4.3 years; BMI: 29.5 (SD 2.9 kg.m2 participated in the research. Each participant received one VFA, and one total body and lumbar spine DXA scan (GE Lunar iDXA. One hundred and twenty vertebral fractures were identified in over half of the sample by VFA. Seventy four were graded mild (grade 1, 40 moderate (grade 2 and 6 severe (grade 3. Multiple vertebral fractures (≥2 were found in 37 players (39%. There were no differences in prevalence between codes, or between forwards and backs (both 1.2 v 1.4; p>0.05. The most common sites of fracture were T8 (n = 23, T9 (n = 18 and T10 (n = 21. The mean (SD lumbar spine bone mineral density Z-score was 2.7 (1.3 indicating high player bone mass in comparison with age- and sex-matched norms. We observed a high number of vertebral fractures using DXA VFA in professional rugby players of both codes. The incidence, aetiology and consequences of vertebral fractures in professional rugby players are unclear, and warrant timely, prospective investigation.

  6. ANTHROPOMETRIC AND PHYSIOLOGICAL CHARACTERISTICS ON INDIAN INTERUNIVERSITY BASKETBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Shyamal Koley

    2010-08-01

    Full Text Available The purpose of this study was two-fold, firstly, to evaluate the anthropometric profile of Indian interuniversity basketball players and, secondly, to search the correlation of body mass index, % body fat, hand grip strength (right dominant and Vo2max,with other anthropometric characteristics studied. Eleven anthropometriccharacteristics, four body composition parameters, two physical and two physiological variables were measured on randomly selected 60 inter-university Indian basketball players (35 males and 25 females aged 18–25 years from Guru Nanak Dev University, Amritsar, Punjab, India with adequate controls (n = 102, 52 males and 50 females. The results indicated that male basketball players were taller (6.63% and heavier (7.31% and female basketball players were slightly taller (0.31% and lighter (3.74% than their control counterparts. One way analysis of variance showed significant (p ≤ .004 - .000 between group differences in all the variables (excepthip circumference between basketball players and controls. In basketball players, significantly positive correlations were found with BMI and other 12 variables, with percent body fat and 7 variables, with right hand grip strength and 12 variables and with Vo2max and other 9 variables, and significantly negative correlationswere found with BMI and other 1 variable (% lean body mass, with percent body fat and other 6 variables, with right hand grip strength and other 2 variables and with Vo2max with other 3 variables. The findings of the present study might be useful in future investigation on player selection, talent identification in the game of basketball and its training program development.

  7. Development of repeated sprint ability in talented youth basketball players.

    Science.gov (United States)

    te Wierike, Sanne C M; de Jong, Mark C; Tromp, Eveline J Y; Vuijk, Pieter J; Lemmink, Koen A P M; Malina, Robert M; Elferink-Gemser, Marije T; Visscher, Chris

    2014-04-01

    Factors affecting repeated sprint ability (RSA) were evaluated in a mixed-longitudinal sample of 48 elite basketball players 14-19 years of age (16.1 ± 1.7 years). Players were observed on 6 occasions during the 2008-09 and 2009-10 seasons. Three following basketball-specific field tests were administered on each occasion: the shuttle sprint test for RSA, the vertical jump for lower body explosive strength (power), and the interval shuttle run test for interval endurance capacity. Height and weight were measured; body composition was estimated (percent fat, lean body mass). Multilevel modeling of RSA development curve was used with 32 players (16.0 ± 1.7 years) who had 2 or more observations. The 16 players (16.1 ± 1.8 years) measured on only 1 occasion were used as a control group to evaluate the appropriateness of the model. Age, lower body explosive strength, and interval endurance capacity significantly contributed to RSA (p ≤ 0.05). Repeated sprint ability improved with age from 14 to 17 years (p ≤ 0.05) and reached a plateau at 17-19 years. Predicted RSA did not significantly differ from measured RSA in the control group (p ≥ 0.05). The results suggest a potentially important role for the training of lower body explosive strength and interval endurance capacity in the development of RSA among youth basketball players. Age-specific reference values for RSA of youth players may assist basketball coaches in setting appropriate goals for individual players.

  8. Design of Emergent and Adaptive Virtual Players in a War RTS Game

    CERN Document Server

    Gutiérrez, José A García; Fernández-Leiva, Antonio J

    2012-01-01

    Basically, in (one-player) war Real Time Strategy (wRTS) games a human player controls, in real time, an army consisting of a number of soldiers and her aim is to destroy the opponent's assets where the opponent is a virtual (i.e., non-human player controlled) player that usually consists of a pre-programmed decision-making script. These scripts have usually associated some well-known problems (e.g., predictability, non-rationality, repetitive behaviors, and sensation of artificial stupidity among others). This paper describes a method for the automatic generation of virtual players that adapt to the player skills; this is done by building initially a model of the player behavior in real time during the game, and further evolving the virtual player via this model in-between two games. The paper also shows preliminary results obtained on a one player wRTS game constructed specifically for experimentation.

  9. THE EVALUATION OF SOME PHYSICAL AND PHYSIOLOGICAL CAHARACTERISTICS OF TURKISH AND FOREIGN NATIONAL BADMINTON TEAM PLAYERS

    Directory of Open Access Journals (Sweden)

    Serkan REVAN

    2007-12-01

    Full Text Available The aim of this study was to evaluate of some physical and physiological characteristics of Turkish and Foreign National Badminton Team Players.The study was participated by 50 players from Turkish team (12 males and 11 females, from foreign team (13 females and 14 males. Body mass index, audio and visual reaction times, anaerobic power, body fat percentage and somatotype components of the participants were determined.While visual right hand reaction times of Turkish Male Badminton Players were better than foreign players, other physical parameters were not found as statistically significant between male player groups. While visual left hand reaction times of Turkish Female Badminton Players were better and mesomorphy values were less than foreign players, in other physical parameters a statistically significant difference could not found between female player groups.As a result, physical and physiological characteristics of Turkish and foreign badminton players were similar.

  10. Isokinetic imbalance of adductor-abductor hip muscles in professional soccer players with chronic adductor-related groin pain.

    Science.gov (United States)

    Belhaj, K; Meftah, S; Mahir, L; Lmidmani, F; Elfatimi, A

    2016-11-01

    This study aims to compare the isokinetic profile of hip abductor and adductor muscle groups between soccer players suffering from chronic adductor-related groin pain (ARGP), soccer players without ARGP and healthy volunteers from general population. Study included 36 male professional soccer players, who were randomly selected and followed-up over two years. Of the 21 soccer players eligible to participate in the study, 9 players went on to develop chronic ARGP and 12 players did not. Ten healthy male volunteers were randomly selected from the general population as a control group. Comparison between the abductor and adductor muscle peak torques for players with and without chronic ARGP found a statistically significant difference on the dominant and non-dominant sides (p muscle significantly stronger than the adductor muscle. In the group of healthy volunteers, the adductor muscle groups were significantly stronger than the abductor muscle groups on both dominant and non-dominant sides (p muscle strength was also significantly decreased on the affected side. This imbalance appears to be a risk factor for adductor-related groin injury. Therefore, restoring the correct relationship between these two agonist and antagonist hip muscles may be an important preventative measure that should be a primary concern of training and rehabilitation programmes.

  11. Lateral Scapular Slide Test and Scapular Mobility in Volleyball Players

    Science.gov (United States)

    Ozunlu, Nihan; Tekeli, Hatice; Baltaci, Gul

    2011-01-01

    Context: The stability of the scapula in relation to the entire moving upper extremity is the key in the throwing sequence. The importance of scapular positioning in volleyball players has been well documented in the literature, but no one has compared scapular positioning between volleyball players and sedentary people. Objective: To compare measurements of scapular mobility obtained using the lateral scapular slide test between volleyball players and sedentary participants without shoulder impairments and to compare changes in scapular mobility in players according to the number of years of sport participation. Design: Cross-sectional study. Setting: University research laboratory. Patients or Other Participants: A total of 121 people at a single university volunteered. Of these, 67 were sedentary (age = 24.3 ± 2.34 years, height = 1.69 ± 0.09 m, mass = 65.1 ± 11.91 kg); 54 were volleyball players from 4 professional teams and were separated into 2 groups according to their years of sport participation. The first group was named young players (n = 31; age = 17.7 ± 2.58 years, height = 1.83 ± 0.10 m, mass = 68.3 ± 12.21 kg, sport participation ≤ 9 years), and the second group was named old players (n = 23; age = 26.9 ± 3.39 years, height = 1.95 ± 4.38 m, mass = 90.7 ± 5.75 kg, sport participation ≥ 10 years). Main Outcome Measure(s): Study participants completed a rating scale for pain and a questionnaire about demographic and shoulder problems. One assessor performed the lateral scapular slide test and additional flexibility measurements around the shoulder girdle. Flexibility (external rotation, internal rotation) and scapular position (1, 2, 3) were compared among groups (young players, old players, sedentary people) and between sides (dominant, nondominant). Results: In sedentary participants, we found differences for position 1 (t66 = 3.327, P = .002), position 2 (t66 = 2.491, P = .004), position 3 (t66 = 2.512, P = .006), and internal rotation

  12. Concussion among female middle-school soccer players.

    Science.gov (United States)

    O'Kane, John W; Spieker, Amy; Levy, Marni R; Neradilek, Moni; Polissar, Nayak L; Schiff, Melissa A

    2014-03-01

    Despite recent increased awareness about sports concussions, little research has evaluated concussions among middle-school athletes. To evaluate the frequency and duration of concussions in female youth soccer players and to determine if concussions result in stopping play and seeking medical care. Prospective cohort study from March 2008 through May 2012 among 4 soccer clubs from the Puget Sound region of Washington State, involving 351 elite female soccer players, aged 11 to 14 years, from 33 randomly selected youth soccer teams. Of the players contacted, 83.1% participated and 92.4% completed the study. Concussion cumulative incidence, incidence rate, and description of the number, type, and duration of symptoms. We inquired weekly about concussion symptoms and, if present, the symptom type and duration, the event resulting in symptom onset, and whether the player sought medical attention or played while symptomatic. Among the 351 soccer players, there were 59 concussions with 43 742 athletic exposure hours. Cumulative concussion incidence was 13.0% per season, and the incidence rate was 1.2 per 1000 athletic exposure hours (95% CI, 0.9-1.6). Symptoms lasted a median of 4.0 days (mean, 9.4 days). Heading the ball accounted for 30.5% of concussions. Players with the following symptoms had a longer recover time than players without these symptoms: light sensitivity (16.0 vs 3.0 days, P = .001), emotional lability (15.0 vs 3.5 days, P = .002), noise sensitivity (12.0 vs 3.0 days, P = .004), memory loss (9.0 vs 4.0 days, P = .04), nausea (9.0 vs 3.0 days, P = .02), and concentration problems (7.0 vs 2.0 days, P = .02). Most players (58.6%) continued to play with symptoms, with almost half (44.1%) seeking medical attention. Concussion rates in young female soccer players are greater than those reported in older age groups, and most of those concussed report playing with symptoms. Heading the ball is a frequent precipitating event. Awareness

  13. Quadriceps tendon injuries in national football league players.

    Science.gov (United States)

    Boublik, Martin; Schlegel, Theodore F; Koonce, Ryan C; Genuario, James W; Kinkartz, Jason D

    2013-08-01

    Distal quadriceps tendon tears are uncommon injuries that typically occur in patients older than 40 years of age, and they have a guarded prognosis. Predisposing factors, prodromal findings, mechanisms of injury, treatment guidelines, and recovery expectations are not well described in high-level athletes. Professional American football players with an isolated tear of the quadriceps tendon treated with timely surgical repair will return to their sport. Case series; Level of evidence, 4. Fourteen unilateral distal quadriceps tendon tears were identified in National Football League (NFL) players from 1994 to 2004. Team physicians retrospectively reviewed training room and clinic records, operative notes, and imaging studies for each of these players. Data on each player were analyzed to identify variables predicting return to play. A successful outcome was defined as returning to play in regular-season NFL games. Eccentric contraction of the quadriceps was the most common mechanism of injury, occurring in 10 players. Only 1 player had antecedent ipsilateral extensor mechanism symptoms. Eleven players had a complete rupture of the quadriceps tendon, and 3 had partial tears. There were no associated knee injuries. All ruptures were treated with surgical repair, 1 of which was delayed after failure of nonoperative treatment. Fifty percent of players returned to play in regular-season NFL games. There was a trend toward earlier draft status for those who returned to play compared with those who did not (draft round, 3.1 ± 2.5 vs. 6.0 ± 2.9, respectively; P = .073). For those who returned to play, the average number of games after injury was 40.9 (range, 12-92). Quadriceps tendon tears are rare in professional American football players, and they usually occur from eccentric load on the extensor mechanism. Prodromal symptoms and predisposing factors are usually absent. Even with timely surgical repair, there is a low rate of return to play in regular-season games. There

  14. Athletic performance outcomes following lumbar discectomy in professional basketball players.

    Science.gov (United States)

    Anakwenze, Okechukwu A; Namdari, Surena; Auerbach, Joshua D; Baldwin, Keith; Weidner, Zachary D; Lonner, Baron S; Huffman, G R; Sennett, Brian J

    2010-04-01

    Retrospective case-control study. To quantify the athletic performance profiles after lumbar discectomy (LD) in a cohort of National Basketball Association (NBA) players in comparison with a control group of matched NBA players who did not undergo LD during the same study period. LD provides symptomatic relief and improved functional outcomes in the majority of patients as assessed by validated measures such as Oswestry Disability Index, Visual Analog Scale, and Short Form-36 (SF-36). Among professional athletes, however, the goal of lumbar HNP treated by discectomy is not only to improve functional status but also, ultimately, to return the player to preinjury athletic performance levels. No study to date has compared the athletic performance profiles before and after discectomy in professional athletes. An analysis of NBA games summaries, weekly injury reports, player profiles, and press releases was performed to identify 24 NBA players who underwent LD for symptomatic lumbar HNP between 1991 and 2007. A 1:2 case: control study was performed using players without history of lumbar HNP who were matched for age, position, experience, and body mass index as control subjects (n = 48). Paired t tests were conducted on the following parameters: games played, minutes per game, points per 40 minutes, rebounds per 40 minutes, assists per 40 minutes, steals per 40 minutes, blocks per 40 minutes, and shooting percentage. For each athletic performance outcome, between-group comparisons evaluating preindex to postindex season performance were done (index season = season of surgery). In the LD group, 18 of 24 players (75%) returned to play again in the NBA, compared with 42 of 48 players (88%, P = 0.31) in the control group. One year after surgery, between-group comparisons revealed statistically significant increase in blocked shots per 40 minutes in the LD (0.18) versus control group (-0.33; P = 0.008) and a smaller decrease in rebounds per 40 minutes in the LD (-0

  15. Infectious diseases in rugby players: incidence, treatment and prevention.

    Science.gov (United States)

    Stacey, A; Atkins, B

    2000-03-01

    Participation in rugby football can expose individuals to a variety of infectious diseases both on and off the field of play. The close physical contact and trauma inherent in playing rugby facilitates the transmission of viral, bacterial and fungal pathogens between players and may also lead to the acquisition of potentially lethal infections from the environment, such as tetanus. In the past few years there have been a number of reported outbreaks of infection amongst rugby players in the medical literature. The appearance of HIV infection has focused attention on the potential for transmission of this and other blood-borne viruses such as hepatitis B and C viruses from bleeding wounds sustained on the rugby field. As a result, various expert bodies have produced guidelines on the management of players with bleeding wounds. Opportunities are now available to rugby players to play outside their own countries, including the third world. This can bring them into contact with a wide range of travel-associated infections, some of which may be life threatening. In view of the above it is clear that rugby players and those who coach and manage rugby teams require information and education on the subject of infection and its prevention, as well as access to appropriate medical care and expertise. Many of the infections seen in rugby players are preventable, e.g. by promoting hygienic facilities and conduct in changing rooms and on the field of play, by exclusion of infected players from contact with others and, in some cases, by immunisation or chemoprophylaxis. Players who present with infections should be assessed, correctly diagnosed (using laboratory investigations where appropriate) and treated, and measures should be taken to prevent spread to team-mates and other contacts while respecting the confidentiality of the individual. Any outbreaks of infection should be reported to the appropriate authorities. There is evidence to suggest that strenuous physical exercise

  16. Iliopsoas and gluteal muscles are asymmetric in tennis players but not in soccer players.

    Directory of Open Access Journals (Sweden)

    Joaquin Sanchis-Moysi

    Full Text Available PURPOSE: To determine the volume and degree of asymmetry of iliopsoas (IL and gluteal muscles (GL in tennis and soccer players. METHODS: IL and GL volumes were determined using magnetic resonance imaging (MRI in male professional tennis (TP and soccer players (SP, and in non-active control subjects (CG (n = 8, 15 and 6, respectively. RESULTS: The dominant and non-dominant IL were hypertrophied in TP (24 and 36%, respectively, P<0.05 and SP (32 and 35%, respectively, P<0.05. In TP the asymmetric hypertrophy of IL (13% greater volume in the non-dominant than in the dominant IL, P<0.01 reversed the side-to-side relationship observed in CG (4% greater volume in the dominant than in the contralateral IL, P<0.01, whilst soccer players had similar volumes in both sides (P = 0.87. The degree of side-to-side asymmetry decreased linearly from the first lumbar disc to the pubic symphysis in TP (r = -0.97, P<0.001, SP (r = -0.85, P<0.01 and CG (r = -0.76, P<0.05. The slope of the relationship was lower in SP due to a greater hypertrophy of the proximal segments of the dominant IL. Soccer and CG had similar GL volumes in both sides (P = 0.11 and P = 0.19, for the dominant and contralateral GL, respectively. GL was asymmetrically hypertrophied in TP. The non-dominant GL volume was 20% greater in TP than in CG (P<0.05, whilst TP and CG had similar dominant GL volumes (P = 0.14. CONCLUSIONS: Tennis elicits an asymmetric hypertrophy of IL and reverses the normal dominant-to-non-dominant balance observed in non-active controls, while soccer is associated to a symmetric hypertrophy of IL. Gluteal muscles are asymmetrically hypertrophied in TP, while SP display a similar size to that observed in controls. It remains to be determined whether the different patterns of IL and GL hypertrophy may influence the risk of injury.

  17. The movement characteristics of English Premiership rugby union players.

    Science.gov (United States)

    Cahill, Nicola; Lamb, Kevin; Worsfold, Paul; Headey, Roy; Murray, Stafford

    2013-01-01

    The purpose of this investigation was to quantify the movement characteristics of elite rugby union players during competitive play and identify whether position-related differences exist. Ninety-eight elite players from eight English Premiership Clubs were tracked using global positioning systems (GPS) during 44 competitive matches throughout the 2010/2011 season. Player positions were defined as: (1) backs or forwards; (2) front, second and back rows, scrum half, inside and outside backs; (3) 15 individual positions (numbers 1-15). Analysis revealed the game is predominantly played at low speeds with little distance covered 'sprinting' by either the backs (50 ± 76 m) or the forwards (37 ± 64 m). The backs travelled greater (P scrum half covered the greatest total distance during a match (7098 ± 778 m) and the front row the least (5158 ± 200 m). The back row covered the greatest distances at 'sprinting' speeds, particularly the number 8 position (77 m). These findings reflect notable differences in the movement characteristics displayed by elite rugby union players in specific positional roles, and reinforce the contemporary view that training programmes for such players ought to be structured with this in mind.

  18. Fitness Profiles of Elite Portuguese Rugby Union Players

    Directory of Open Access Journals (Sweden)

    Vaz Luís

    2014-07-01

    Full Text Available The aim of this study was to describe the fitness profiles of senior elite Portuguese rugby players. Forty-six senior Portuguese rugby players, classified as backs (n=22; age 26.2±2.8 and forwards (n=24; age 26.7±2.9 were assessed during physical testing sessions carried out for the Portuguese National rugby team. The body composition, maximum strength and anaerobic capacity of players are hypothesized to be important physical characteristics as successful performance in rugby is predicated on the ability to undertake skilled behaviours both quickly and whilst withstanding large forces when in contact situations. No absolute differences were found between the backs and forwards for the speed performance variables although positional differences were found across all speeds when assessed relative to body mass since the forwards were significantly heavier. Coaches and the management team can use this information for monitoring progressive improvements in the physiological capacities of rugby players. These physical characteristics of elite rugby players provide normative profiles for specific positions and should form the basis of developmental programmes for adolescents.

  19. Player guild dynamics and evolution in massively multiplayer online games.

    Science.gov (United States)

    Chen, Chien-Hsun; Sun, Chuen-Tsai; Hsieh, Jilung

    2008-06-01

    In the latest versions of massively multiplayer online games (MMOGs), developers have purposefully made guilds part of game environments. Guilds represent a powerful method for giving players a sense of online community, but there is little quantitative data on guild dynamics. To address this topic, we took advantage of a feature found in one of today's most popular MMOGs (World of Warcraft) to collect in-game data: user interfaces that players can modify and refine. In addition to collecting data on in-game player activities, we used this feature to observe and investigate how players join and leave guilds. Data were analyzed for the purpose of identifying factors that propel game-world guild dynamics and evolution. After collecting data for 641,805 avatars on 62 Taiwanese World of Warcraft game servers between February 10 and April 10, 2006, we created five guild type categories (small, large, elite, newbie, and unstable) that have different meanings in terms of in-game group dynamics. By viewing players as the most important resource affecting guild life cycles, it is possible to analyze game worlds as ecosystems consisting of evolving guilds and to study how guild life cycles reflect game world characteristics.

  20. How the Iranian Football Coaches and Players Know About Doping?

    Science.gov (United States)

    Seif Barghi, Tohid; Halabchi, Farzin; Dvorak, Jiri; Hosseinnejad, Heydar

    2015-01-01

    Background: Nowadays, doping is an intricate dilemma. Football is the nationally popular sport in Iran. On the other hand, doping is a serious health hazard sport faces today. Studies dealing with athletes’ knowledge, attitudes and behavior concerning doping in football are scarce. Objectives: Therefore, we aimed to investigate the knowledge and attitudes toward doping among the football coaches and players. Patients and Methods: In a cross sectional study, 375 participants (239 football players and 136 coaches) were studied. A specially made questionnaire was applied. In this study, football teams of different provinces of the country were selected by randomized clustered sampling and questionnaires were distributed among coaches and players. Results: Knowledge of football coaches and players in three categories of doping definitions, recognition of prohibited drugs and side effects of anabolic steroids was poor or moderate in 45.3%, 88.5% and 96.5%, respectively. Conclusions: Football players and coaches have poor knowledge about doping in Iran. Moreover, they believe in some inappropriate myths without any scientific or rational basis.It seems necessary to design a comprehensive educational program for all of the athletes and coaches in Iran. PMID:26448840

  1. Efficiently detecting outlying behavior in video-game players

    Directory of Open Access Journals (Sweden)

    Young Bin Kim

    2015-12-01

    Full Text Available In this paper, we propose a method for automatically detecting the times during which game players exhibit specific behavior, such as when players commonly show excitement, concentration, immersion, and surprise. The proposed method detects such outlying behavior based on the game players’ characteristics. These characteristics are captured non-invasively in a general game environment. In this paper, cameras were used to analyze observed data such as facial expressions and player movements. Moreover, multimodal data from the game players (i.e., data regarding adjustments to the volume and the use of the keyboard and mouse was used to analyze high-dimensional game-player data. A support vector machine was used to efficiently detect outlying behaviors. We verified the effectiveness of the proposed method using games from several genres. The recall rate of the outlying behavior pre-identified by industry experts was approximately 70%. The proposed method can also be used for feedback analysis of various interactive content provided in PC environments.

  2. Complexity of comparison of influence of players in simple games

    CERN Document Server

    Aziz, Haris

    2008-01-01

    Coalitional voting games appear in different forms in multi-agent systems, social choice and threshold logic. In this paper, the complexity of comparison of influence between players in coalitional voting games is characterized. The possible representations of simple games considered are simple games represented by winning coalitions, minimal winning coalitions, weighted voting game or a multiple weighted voting game. The influence of players is gauged from the viewpoint of basic player types, desirability relations and classical power indices such as Shapley-Shubik index, Banzhaf index, Holler index, Deegan-Packel index and Chow parameters. Among other results, it is shown that for a simple game represented by minimal winning coalitions, although it is easy to verify whether a player has zero or one voting power, computing the Banzhaf value of the player is #P-complete. Moreover, it is proved that multiple weighted voting games are the only representations for which it is NP-hard to verify whether the game i...

  3. Psychological and sport-specific characteristics of football players.

    Science.gov (United States)

    Junge, A; Dvorak, J; Rösch, D; Graf-Baumann, T; Chomiak, J; Peterson, L

    2000-01-01

    It is hypothesized that players of different levels of play might differ not only in their football skills but also in their way of playing football and with respect to psychological factors such as concentration, reaction time, or competitive anxiety. The psychological characteristics of a player might influence his way of playing football (in particular with respect to fair play) and also his risk of injury. A group of 588 football players were studied by questionnaire; additionally, reaction time tests were performed. Psychological characteristics were assessed by three established self-evaluation questionnaires: the Athletic Coping Skills Inventory, the State Competitive Anxiety Test, and the State-Trait-Anger-Expression-Inventory. Football-specific characteristics that were investigated included playing experience and positions played, style of play, number of training hours and games, as well as aspects of fair play. Reaction time was tested twice: without the influence of physical exercise and immediately after a 12-minute run. A significant reduction in reaction time was observed after physical exercise. In high-level players, the reaction time immediately after the 12-minute run was significantly shorter than it was in low-level players. The questionnaire answers given regarding fair play clearly indicated that fair play is not paid sufficient respect. The relationship between psychological characteristics and attitudes toward fair play was analyzed and discussed.

  4. Special considerations in the medical management of professional basketball players.

    Science.gov (United States)

    Steingard, S A

    1993-04-01

    The NBA basketball players are among the finest athletes in the world. That along with the increased popularity of the NBA has put a premium on the health of the players. The course of the season puts tremendous stress and strain on players. As medical illnesses occur, the physician may feel increased pressure to put the ill player back into the line-up. One cannot let the pressure for the player to return to activity interfere with good medical practice. At times, it is difficult to allow for the natural course of an illness, however, as discussed in this article, sometimes this is exactly what needs to be done. The temptation to overtreat is also seen in some team physicians. This too must be avoided. Along with proper treatment, there is the need for education of the athletes both in social interactions and in diet and life-style. Then we, as team physicians, can sit back and enjoy the performance on the court.

  5. Fitness Profiles of Elite Portuguese Rugby Union Players

    Science.gov (United States)

    Vaz, Luís; Morais, Tomaz; Rocha, Henrique; James, Nic

    2014-01-01

    The aim of this study was to describe the fitness profiles of senior elite Portuguese rugby players. Forty-six senior Portuguese rugby players, classified as backs (n=22; age 26.2±2.8) and forwards (n=24; age 26.7±2.9) were assessed during physical testing sessions carried out for the Portuguese National rugby team. The body composition, maximum strength and anaerobic capacity of players are hypothesized to be important physical characteristics as successful performance in rugby is predicated on the ability to undertake skilled behaviours both quickly and whilst withstanding large forces when in contact situations. No absolute differences were found between the backs and forwards for the speed performance variables although positional differences were found across all speeds when assessed relative to body mass since the forwards were significantly heavier. Coaches and the management team can use this information for monitoring progressive improvements in the physiological capacities of rugby players. These physical characteristics of elite rugby players provide normative profiles for specific positions and should form the basis of developmental programmes for adolescents. PMID:25114750

  6. Relative age effect and selection of young basketball players

    Directory of Open Access Journals (Sweden)

    Vučković Igor

    2013-01-01

    Full Text Available Purpose of the present study was to examine whether influence of relative age effect (RAE exists or not in the selected 13 year old basketball players. Subjects were 20 basketball players (HT=177.35cm±6.73, BW=61.42kg±8.98, average age 13 years and 7 months ±.28, average experience in basketball training 4 years and 6 months ±1.15. Sample was divided in two groups: 11 players born in first half of the year and 9 players born in the second half of the year. One-way ANOVA was used in order to analyze the differences between the two groups of players in set of anthropometric variables (body height, arm span, standing reach height, body weight and percentage of body fat, motor variables (velocity of neuromuscular reaction time, vertical jump, 5 meters sprint, 10 meters sprint, 20 meters sprint, T-test, Zig-zag test, ball throw from sitting position, Sit-ups for 30 seconds and standing forward bend and one functional variable (20-M shuttle run test. Subjects do not differ in applied set of parameters, except in on variable (sit-ups for 30 seconds, p=.040. It was concluded that RAE does not exist in this sample of examinees.

  7. MEANING TO BE VOLLEYBALL PLAYER IN CAREER TRANSITION PHASE

    Directory of Open Access Journals (Sweden)

    Adriana Justino

    2016-09-01

    Full Text Available The objective of this study is to assess the meaning of being that a volleyball player for the under-19 players who are experiencing a transition in their in career. Sixteen male players aged 17 and 18 were evaluated, by being asked the triggering question “What does being a volleyball player mean to you?” The analysis of the discourses was carried out according to the procedures recommended by Miles & Huberman (2004. Four response categories resulted: psychoemotional and behavioral skills, emotions in sport, recognition and financial return, skills as an athlete/player. The athletes showed that the meaning of sport lies especially in the passion for practice, but also, in the improving of their tactics and techniques, in the development of psychoemotional and behavioral skills, in the professional recognition and, to a lesser degree, in the financial aspect. Most athletes state they intend to continue in the juvenile sports categories, therefore, understanding the meaning of this activity in their life can be the key to the elaboration of a plan of psychological preparation whose aim is to provide support to their needs in this moment of professional choice.

  8. Ιnjuries in greek amateur soccer players

    Directory of Open Access Journals (Sweden)

    GEORGIOS TSIGANOS

    2007-01-01

    Full Text Available The purpose of this study was to record retrospectivelythe epidemiology of injuries in amateur Greek soccer players. Three hundred and one (301 amateur soccer playersvoluntarily participated in the study. Participants answered aspecially-designed questionnaire that included questionsabout demographics, playing surface, division, position,hours of training plus participation, the use of stretching orprophylactic tape, the injury mechanism, the location andtype of injury. During the five years these soccer playerssustained a total of 1.745 injuries, that diagnosed by the orthopedist of the team. Most of injuries were strains (33%,overuse (27% and sprains (25%. The location of injurieswas the thigh (38 %, ankle (27% and knee (13%. Therewas a significant difference in the total number of injuriesamong soccer players with or without scoliosis (t=3.152,p. 0.05 and players that played on sand/dirt (gravel, whosustained more injuries than the players who played on artificial grass or on grass (t=3.413, p. 0.05. No differenceswere found in the other measurement parameters. The results of our study shows that spine deformities and groundsurfaces are the factors that causes more injuries in amateurGreek soccer players.

  9. A Discrete Evolutionary Model for Chess Players' Ratings

    CERN Document Server

    Fenner, Trevor; Loizou, George

    2011-01-01

    The Elo system for rating chess players, also used in other games and sports, was adopted by the World Chess Federation over four decades ago. Although not without controversy, it is accepted as generally reliable and provides a method for assessing players' strengths and ranking them in official tournaments. It is generally accepted that the distribution of players' rating data is approximately normal but, to date, no stochastic model of how the distribution might have arisen has been proposed. We propose such an evolutionary stochastic model, which models the arrival of players into the rating pool, the games they play against each other, and how the results of these games affect their ratings. Using a continuous approximation to the discrete model, we derive the distribution for players' ratings at time $t$ as a normal distribution, where the variance increases in time as a logarithmic function of $t$. We validate the model using published rating data from 2007 to 2010, showing that the parameters obtained...

  10. Adaptivity to Age, Gender, and Gaming Platform Topology in Physical Multi-Player Games

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Friðriksson, Rafn Vídalín; Björnsson, Davíð Þór

    2012-01-01

    In games where players are competing against each other, it can be of interest to ensure that all players are challenged according to their individual skills. In order to investigate such adaptivity to the individual player in physical multi-player games, we developed a game on modular interactive...... and adults, and between male and female players. Also, results show statistically significant differences in the game interactions between different physical set-ups of the modular interactive tiles, i.e. the interaction depended on the topology of the modular tiles set-up. Changing the physical set......-up of the physical game platform changes the interaction and performance of the players....

  11. Is There Chronic Brain Damage in Retired NFL Players? Neuroradiology, Neuropsychology, and Neurology Examinations of 45 Retired Players.

    Science.gov (United States)

    Casson, Ira R; Viano, David C; Haacke, E Mark; Kou, Zhifeng; LeStrange, Danielle G

    2014-09-01

    Neuropathology and surveys of retired National Football League (NFL) players suggest that chronic brain damage is a frequent result of a career in football. There is limited information on the neurological statuses of living retired players. This study aimed to fill the gap in knowledge by conducting in-depth neurological examinations of 30- to 60-year-old retired NFL players. In-depth neurological examinations of 30- to 60-year-old retired players are unlikely to detect objective clinical abnormalities in the majority of subjects. A day-long medical examination was conducted on 45 retired NFL players, including state-of-the-art magnetic resonance imaging (MRI; susceptibility weighted imaging [SWI], diffusion tensor imaging [DTI]), comprehensive neuropsychological and neurological examinations, interviews, blood tests, and APOE (apolipoprotein E) genotyping. Level 3. Participants' histories focused on neurological and depression symptoms, exposure to football, and other factors that could affect brain function. The neurological examination included Mini-Mental State Examination (MMSE) evaluation of cognitive function and a comprehensive search for signs of dysarthria, pyramidal system dysfunction, extrapyramidal system dysfunction, and cerebellar dysfunction. The Beck Depression Inventory (BDI) and Patient Health Questionnaire (PHQ) measured depression. Neuropsychological tests included pen-and-paper and ImPACT evaluation of cognitive function. Anatomical examination SWI and DTI MRI searched for brain injuries. The results were statistically analyzed for associations with markers of exposure to football and related factors, such as body mass index (BMI), ethanol use, and APOE4 status. The retired players' ages averaged 45.6 ± 8.9 years (range, 30-60 years), and they had 6.8 ± 3.2 years (maximum, 14 years) of NFL play. They reported 6.9 ± 6.2 concussions (maximum, 25) in the NFL. The majority of retired players had normal clinical mental status and central

  12. Intermittent Testing and Training for High-Level Football Players

    DEFF Research Database (Denmark)

    Ingebrigtsen, Jørgen

    systematic differences between the playing positions can be detected. Lately, field tests have become more frequently used in football than the laboratory tests used in Study I. Study II therefore aims to assess the validity of one of them, the Yo-Yo Intermittent Recovery test level 2 (Yo-Yo IR2). Along...... with other field tests the Yo-Yo IR2 has become an important tool for monitoring the physical fitness of football players. However, the burden of testing, for players (physically and mentally) and the coaching staff (time consuming), is large and there is a probability that the tests may contain overlapping...... on the Yo-Yo IR2 test and other field- and laboratory tests of intermittent interval training performed as anaerobic speed-endurance production training is very limited for football players. Hence, this latter question is examined in Study IV.In Study I we find no differences in anthropometric...

  13. Somatotype of competitive youth soccer players from Brazil.

    Science.gov (United States)

    Fidelix, Yara Lucy; Berria, Juliane; Ferrari, Elisa Pinheiro; Ortiz, Jaelson Gonçalves; Cetolin, Tiago; Petroski, Edio Luiz

    2014-09-29

    The aim of this study was to identify the morphological configuration of youth athletes from professional soccer clubs and to verify their differences according to the tactical position on the field. Overall, 67 male players aged 15 to 17 years were evaluated. The examined anthropometric measurements included body mass, body height, skinfolds (triceps, subscapular, supraspinal and medial calf), girths (flexed and tensed arm and calf) and breadths (humerus and femur). For statistical purposes, analysis of variance and post hoc Bonferroni and Kruskal-Wallis tests were used. We concluded that goalkeepers were heavier and taller than center backs (p = 0.015 and p = 0.001), midfielders (p = 0.005 and p somatotype for defense, forward and goalkeeper positions was a balanced mesomorph. Midfield players showed ectomorphic-mesomorph characteristics. It was concluded that goalkeepers were characterized as being taller and heavier and that somatotype features of athletes were similar between positions, except for midfield players.

  14. Social dimensions of expertise in World of Warcraft players

    Directory of Open Access Journals (Sweden)

    Mark Chen

    2009-03-01

    Full Text Available Expertise development in the massively multiplayer online game World of Warcraft (Blizzard Entertainment, 2004 depends greatly on a player's use of social skills to gain access to expert player groups and accrue social and cultural capital. Drawn from ethnographic research, this paper maps out various forms of expert practice and highlights the social aspects of game play that often eclipse the importance of game-mechanics knowledge. At the time of this research, playing World of Warcraft and developing expertise in the game happened roughly within a two-stage process: (1 leveling up, or advancing one's character or avatar while learning the mechanics of the game, and (2 drawing on social capital gained during the first stage to join a group of up to 40 players to partake in high-end or endgame content.

  15. Verbal aggressiveness and state anxiety of volleyball players and coaches.

    Science.gov (United States)

    Bekiari, Alexandra; Patsiaouras, Asterios; Kokaridas, Dimitrios; Sakellariou, Kimon

    2006-10-01

    The purpose of the present study was to examine the relation of verbal aggressiveness and state anxiety (somatic, cognitive, and self-confidence) in sports settings based on the ratings by volleyball coaches and their athletes. The sample consisted of volleyball athletes (n=208; 98 men and 110 women) and their coaches (n=20; 16 men and 4 women). Analysis showed that male volleyball players rated somatic anxiety higher and were more affected by the verbal aggressiveness of their coaches than female volleyball players. No mean differences were significant for male and female coaches on somatic or cognitive anxiety, self-confidence, or verbal aggressiveness. Also, correlation between subscale scores for male and female volleyball players and coaches was found. The correlations of verbal aggressiveness with self-confidence and anxiety were positive for these athletes, leading them to better behavior. This relationship needs further examination in sport settings.

  16. METRIC TESTS CHARACTERISTIC FOR ESTIMATING JUMPING FOR VOLLEYBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Toplica Stojanović

    2008-08-01

    Full Text Available With goal to establish metric tests characteristics for estimating jumping for volleyball players, it was organized a pilot research on pattern of 23 volleyball players from cadet team and 23 students from high-school. For needs of this research four tests are valid for estimation, jump in block with left and right leg and jump in spike with left and right leg. Each test has been taken three times, so that we could with test-re test method determine their reliability, and with factor analysis their validity. Data were processed by multivariate analysis (item analysis, factor analysis from statistical package „Statistica 6.0 for windows“. On the results of research and discussion we can say that the tests had high coefficient of reliability, as well as factor validity, and these tests can be used to estimate jumping for volleyball players.

  17. Modeling the Semiotic Structure of Player-Characters

    DEFF Research Database (Denmark)

    Vella, Daniel

    2014-01-01

    When game studies has tackled the player-character, it has tended to do so by means of an opposition to the notion of the avatar, with the result that the ontological and semiotic nature of the character in itself has not been given due attention. This paper draws on understandings of character...... from the fields of narratology and literary theory to highlight the double-layered ontology of character as both a possible individual and as a semiotic construction. Uri Margolin’s narratological model of character signification is used as the basis for developing a semiotic-structural model...... of the player-character that addresses its specific medialities and formal nature – a task which is performed through illustrative close examinations of the player-characters in The Last of Us (Naughty Dog 2013) and Gone Home (The Fullbright Company 2013)....

  18. Three-player conflicting interest games and nonlocality

    Science.gov (United States)

    Bolonek-Lasoń, Katarzyna

    2017-08-01

    We outline the general construction of three-player games with incomplete information which fulfil the following conditions: (i) symmetry with respect to the permutations of players; (ii) the existence of an upper bound for total payoff resulting from Bell inequalities; (iii) the existence of both fair and unfair Nash equilibria saturating this bound. Conditions (i)-(iii) imply that we are dealing with conflicting interest games. An explicit example of such a game is given. A quantum counterpart of this game is considered. It is obtained by keeping the same utilities but replacing classical advisor by a quantum one. It is shown that the quantum game possesses only fair equilibria with strictly higher payoffs than in the classical case. This implies that quantum nonlocality can be used to resolve the conflict between the players.

  19. Two-player envy-free multi-cake division

    CERN Document Server

    Cloutier, John; Su, Francis Edward

    2009-01-01

    We introduce a generalized cake-cutting problem in which we seek to divide multiple cakes so that two players may get their most-preferred piece selections: a choice of one piece from each cake, allowing for the possibility of linked preferences over the cakes. For two players, we show that disjoint envy-free piece selections may not exist for two cakes cut into two pieces each, and they may not exist for three cakes cut into three pieces each. However, there do exist such divisions for two cakes cut into three pieces each, and for three cakes cut into four pieces each. The resulting allocations of pieces to players are Pareto-optimal with respect to the division. We use a generalization of Sperner's lemma on the polytope of divisions to locate solutions to our generalized cake-cutting problem.

  20. Psychosocial Stress and Sport Injuries in Tennis Players

    Directory of Open Access Journals (Sweden)

    Amador Blas Redondo

    2011-09-01

    Full Text Available The purpose of this study was to assess the perceived social stress and its relation to sports injuries in tennis players. Sixty-three male tennis players, with a mean age of 31.62 years (SD = 8.93, Sports Clubs belonging to the Province of Alicante (Spain completed instruments of psychosocial stress and injuries sustained during the previous year the assessment. The results indicate that life events experienced was related to some of the injuries suffered by players. Relationships were found between the degree of psychological stress experienced and the negative evaluation of this strain, the type (lesions on wrists, ankles and sprains, and severity of injuries (minor injuries.

  1. Adaptations to speed endurance training in highly trained soccer players

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Fiorenza, Matteo; Lund, Anders

    2016-01-01

    PURPOSE: The present study examined whether a period of additional speed endurance training would improve intense intermittent exercise performance in highly trained soccer players during the season and whether the training changed aerobic metabolism and the level of oxidative enzymes in type I...... and II muscle fibers. METHODS: During the last nine weeks of the season, thirteen semi-professional soccer players performed additional speed endurance training sessions consisting of 2-3 sets of 8 - 10 repetitions of 30 m sprints with 10 s of passive recovery (SET). Before and after SET, subjects...... in type I and II fibers did not change. CONCLUSION: In highly trained soccer players, additional speed endurance training is associated with an improved ability to perform repeated high-intensity work. To what extent the training-induced changes in V˙O2 kinetics and mechanical efficiency in type I fibers...

  2. Biomechanics of Heading a Soccer Ball: Implications for Player Safety

    Directory of Open Access Journals (Sweden)

    Charles F. Babbs

    2001-01-01

    Full Text Available To better understand the risk and safety of heading a soccer ball, the author created a set of simple mathematical models based upon Newton�s second law of motion to describe the physics of heading. These models describe the player, the ball, the flight of the ball before impact, the motion of the head and ball during impact, and the effects of all of these upon the intensity and the duration of acceleration of the head. The calculated head accelerations were compared to those during presumably safe daily activities of jumping, dancing, and head nodding and also were related to established criteria for serious head injury from the motor vehicle crash literature. The results suggest heading is usually safe but occasionally dangerous, depending on key characteristics of both the player and the ball. Safety is greatly improved when players head the ball with greater effective body mass, which is determined by a player�s size, strength, and technique. Smaller youth players, because of their lesser body mass, are more at risk of potentially dangerous headers than are adults, even when using current youth size balls. Lower ball inflation pressure reduces risk of dangerous head accelerations. Lower pressure balls also have greater “touch” and “playability”, measured in terms of contact time and contact area between foot and ball during a kick. Focus on teaching proper technique, the re-design of age-appropriate balls for young players with reduced weight and inflation pressure, and avoidance of head contact with fast, rising balls kicked at close range can substantially reduce risk of subtle brain injury in players who head soccer balls.

  3. Head Impact Exposure and Neurologic Function of Youth Football Players.

    Science.gov (United States)

    Munce, Thayne A; Dorman, Jason C; Thompson, Paul A; Valentine, Verle D; Bergeron, Michael F

    2015-08-01

    Football players are subjected to repetitive impacts that may lead to brain injury and neurologic dysfunction. Knowledge about head impact exposure (HIE) and consequent neurologic function among youth football players is limited. This study aimed to measure and characterize HIE of youth football players throughout one season and explore associations between HIE and changes in selected clinical measures of neurologic function. Twenty-two youth football players (11-13 yr) wore helmets outfitted with a head impact telemetry (HIT) system to quantify head impact frequency, magnitude, duration, and location. Impact data were collected for each practice (27) and game (9) in a single season. Selected clinical measures of balance, oculomotor performance, reaction time, and self-reported symptoms were assessed before and after the season. The median individual head impacts per practice, per game, and throughout the entire season were 9, 12, and 252, respectively. Approximately 50% of all head impacts (6183) had a linear acceleration between 10g and 20g, but nearly 2% were greater than 80g. Overall, the head impact frequency distributions in this study population were similar in magnitude and location as in high school and collegiate football, but total impact frequency was lower. Individual changes in neurologic function were not associated with cumulative HIE. This study provides a novel examination of HIE and associations with short-term neurologic function in youth football and notably contributes to the limited HIE data currently available for this population. Whereas youth football players can experience remarkably similar head impact forces as high school players, cumulative subconcussive HIE throughout one youth football season may not be detrimental to short-term clinical measures of neurologic function.

  4. In-season training periodization of professional soccer players

    Directory of Open Access Journals (Sweden)

    A Los Arcos

    2017-04-01

    Full Text Available The aim of this study was to quantify the seasonal perceived respiratory and muscular training loads (i.e., sRPEres-TL and sRPEmus-TL completed by elite-oriented young professional soccer players. Twentyfour players (20.3 ± 2.0 years belonging to the same reserve team of a Spanish La Liga club participated in this study. Only the players that were available to train for a whole week with the team and also to play the weekly game were considered: Starters, players that participated in the match for at least 45 min and Non- Starters, players that did not participate or played less than 45 minutes in the match. The competitive period was analysed after the division into 5x6-8 week blocks and 35x1 week microcycles. Data were also analysed with respect to number of days before the immediate match. Weekly TL variation across the in-season blocks was trivial-small for both groups except between Block 2 and Block 3 (ES= moderate. Substantial TL differences (ES= small–very likely were found between training days, the TL pattern being a progressive increase up to MD-3 followed by a decrease until MD-1. Except for the match, sRPEres-/sRPEmus-TL was very similar between Starters and Non-Starters. In summary, perceived TL across the season displayed limited variation. Coaches periodized training contents to attain the highest weekly TL 72 hours before the match to progressively unload the players between MD-3 and the match day. The data revealed that the TL arising from the weekly game was solely responsible for the observed higher weekly TL of Starters in comparison with Non-Starters.

  5. Influence of fatigue on tackling technique in rugby league players.

    Science.gov (United States)

    Gabbett, Tim J

    2008-03-01

    This study investigated the influence of fatigue on tackling technique in rugby league players and determined the relationship between selected physiological capacities and fatigue-induced decrements in tackling technique. Eight rugby league players underwent a standardized one-on-one tackling drill in a 10-m grid. Players performed the one-on-one tackling drill before strenuous exercise and following game-specific repeated-effort exercise of progressively increasing intensities (corresponding to moderate, heavy, and very heavy intensity) in order to induce fatigue that was representative of match conditions. Video footage was taken from the rear, side, and front of the defending player. Tackling technique was objectively assessed using standardized technical criteria. In addition, all players underwent measurements of standard anthropometry (height, body mass, and sum of 7 skinfold measurements), speed (10-, 20-, and 40-m sprint), muscular power (vertical jump), agility (L run), and estimated maximal aerobic power (VO2max multistage fitness test). A progressive increase in total repeated-effort time, heart rate, blood lactate concentration, and ratings of perceived exertion occurred throughout the repeated-effort protocol, demonstrating a progressive increase in intensity and fatigue. Fatigue resulted in progressive reductions in tackling technique. Players with the best tackling technique in a nonfatigued state demonstrated the greatest decrement in tackling technique under fatigued conditions. In addition, a significant association was observed between estimated VO2max (r = -0.62) and agility (r = 0.68) and fatigue-induced decrements in tackling technique. From a practical perspective, these findings suggest that strength and conditioning programs designed to develop endurance, change of direction speed, and anticipation skills may reduce fatigue-induced decrements in tackling technique. Furthermore, any defensive drills designed to improve tackling technique

  6. Computing Sequential Equilibria for Two-Player Games

    DEFF Research Database (Denmark)

    Miltersen, Peter Bro; Sørensen, Troels Bjerre

    2006-01-01

    Koller, Megiddo and von Stengel showed how to efficiently compute minimax strategies for two-player extensive-form zero-sum games with imperfect information but perfect recall using linear programming and avoiding conversion to normal form. Koller and Pfeffer pointed out that the strategies...... a sequential equilibrium are computed. In particular, we show that a sequential equilibrium for a two-player zero-sum game with imperfect information but perfect recall can be found in polynomial time. In addition, the equilibrium we find is normal-form perfect. Our technique generalizes to general-sum games...

  7. The expected-outcome model of two-player games

    CERN Document Server

    Abramson, Bruce

    1990-01-01

    The Expected-Outcome Model of Two-Player Games deals with the expected-outcome model of two-player games, in which the relative merit of game-tree nodes, rather than board positions, is considered. The ambiguity of static evaluation and the problems it generates in the search system are examined and the development of a domain-independent static evaluator is described. Comprised of eight chapters, this book begins with an overview of the rationale for the mathematical study of games, followed by a discussion on some previous artificial intelligence (AI) research efforts on game-trees. The nex

  8. Radiographic knee osteoarthritis in ex-elite table tennis players

    Directory of Open Access Journals (Sweden)

    Rajabi Reza

    2012-02-01

    Full Text Available Abstract Background Table tennis involves adoption of the semi-flexed knee and asymmetrical torsional trunk movements creating rotational torques on the knee joint which may predispose players to osteoarthritis (OA of the knee. This study aims to compare radiographic signs of knee OA and associated functional levels in ex-elite male table tennis players and control subjects. Methods Study participants were 22 ex-elite male table tennis players (mean age 56.64 ± 5.17 years with 10 years of involvement at the professional level and 22 non-athletic males (mean age 55.63 ± 4.08 years recruited from the general population. A set of three radiographs taken from each knee were evaluated by an experienced radiologist using the Kellgren and Lawrence (KL scale (0-4 to determine radiographic levels of OA severity. The intercondylar distance was taken as a measure of lower limb angulation. Participants also completed the pain, stiffness, and physical function categories of the Western Ontario and McMaster University Osteoarthritis Index (WOMAC 3.1 questionnaire. Results The results showed 78.3% of the ex-elite table tennis players and 36.3% of controls had varying signs of radiographic knee OA with a significant difference in the prevalence levels of definite radiographic OA (KL scale > 2 found between the two groups (P ≤ 0.001. Based on the WOMAC scores, 68.2% of the ex-elite table tennis players reported symptoms of knee pain compared with 27.3% of the controls (p = 0.02 though no significant differences were identified in the mean physical function or stiffness scores between the two groups. In terms of knee alignment, 73.7% of the ex-elite athletes and 32% of the control group had signs of altered lower limb alignment (genu varum (p = 0.01. Statistical differences were found in subjects categorized as having radiographic signs of OA and altered lower limb alignment (p = 0.03. Conclusions Ex-elite table tennis players were found to have increased

  9. Nearly All Autopsied NFL Players Show Trauma-Linked Brain Disease

    Science.gov (United States)

    ... gov/news/fullstory_167405.html Nearly All Autopsied NFL Players Show Trauma-Linked Brain Disease No position ... 2017 (HealthDay News) -- Ninety-nine percent of former NFL players who donated their brain to science turned ...

  10. First Days of Preseason Practice Pose Big Heat Risks for College Football Players

    Science.gov (United States)

    ... Preseason Practice Pose Big Heat Risks for College Football Players Coaches, trainers need to be aware of ... FRIDAY, Aug. 26, 2016 (HealthDay News) -- As college football players trade in their beach towels for helmets ...

  11. Postural stability decreases in elite young soccer players after a competitive soccer match

    DEFF Research Database (Denmark)

    Brito, João; Fontes, Ivo; Ribeiro, Fernando

    2012-01-01

    To investigate the effects of an official soccer match on postural stability in youth elite soccer players.......To investigate the effects of an official soccer match on postural stability in youth elite soccer players....

  12. Factors associated with deep tissue injury in male wheelchair basketball players of a Japanese national team

    Directory of Open Access Journals (Sweden)

    Hirotaka Mutsuzaki

    2014-04-01

    Full Text Available Maintenance of the sporting activity of elite athletes in adapted sports can be difficult if a secondary disorder, such as a pressure ulcer, occurs. Pressure ulcers result from deep tissue injuries by external pressure. The purpose of this study was to use ultrasonography to investigate deep tissue injuries in male wheelchair basketball players of a Japanese national team, and to determine factors associated with the injuries (e.g., body mass index, class of wheelchair basketball, underlying disease, length of athletic career, and whether use of wheelchair is primarily for playing basketball. Twenty male Japanese wheelchair basketball players on the national team for the 2012 London Paralympic Games (12 representative players and eight candidate representative players participated in this study. The sacral region and bilateral ischial regions in each athlete were examined by ultrasonography to detect low-echoic lesions indicative of deep tissue injuries. Nine (45% players had low-echoic lesions, which were detected in 10 of 60 areas. Eight lesions were detected in the sacral region and two lesions were detected in the ischial region. More players with spinal cord injury had low-echoic lesions [9 (69.2% of 13 players], compared to players with skeletal system disease [0 (0% of 7 players, p = 0.002]. Players who used a wheelchair in daily life were more likely to have low-echoic lesions [8 (66.74% of 12 players], compared to players who primarily used a wheelchair for playing basketball [1 (12.5% of 8 players, p = 0.010]. Deep tissue injuries were detected in 45% of male Japanese wheelchair basketball players on the national team. Players with spinal cord injury and players who used a wheelchair in daily life were more likely to have deep tissue injuries, particularly in the sacral region. The lesions were small, but a periodic medical check should be performed to maintain athletes' sporting life.

  13. Physical Characteristics and Performance of Japanese Top-Level American Football Players.

    Science.gov (United States)

    Yamashita, Daichi; Asakura, Masaki; Ito, Yoshihiko; Yamada, Shinzo; Yamada, Yosuke

    2017-09-01

    Yamashita, D, Asakura, M, Ito, Y, Yamada, S, and Yamada, Y. Physical characteristics and performance of Japanese top-level American football players. J Strength Cond Res 31(9): 2455-2461, 2017-This study aimed to compare the physical characteristics and performance between top-level nonprofessional football players in Japan and National Football League (NFL) Combine invited players and between top-level and middle-level players in Japan to determine the factors that enhance performance in international and national competitions. A total of 168 American football players (>20 years) in Japan participated in an anthropometric (height and weight) and physical (vertical jump, long jump, 40-yard dash, pro-agility shuttle, 3-cone drill, and bench press repetition test) measurement program based on the NFL Combine program to compete in the selection of candidates for the Senior World Championship. All players were categorized into 1 of the 3 position groups based on playing position: skill players, big skill players, and linemen. Japanese players were additionally categorized into selected and nonselected players for the second tryout. The NFL Combine candidates had significantly better performance than selected Japanese players on all variables except on performance related to quickness among the 3 position groups. Compared with nonselected players, selected Japanese skill players had better performance in the 40-yard dash and bench press test and big skill players had better performance in the vertical jump, broad jump, and 40-yard dash. Selected and nonselected Japanese linemen were not different in any measurements. These results showed the challenges in American football in Japan, which include not only improving physical performance of top-level players, but also increasing the number of football players with good physical performance.

  14. Physical Characteristics and Performance of Japanese Top-Level American Football Players

    Science.gov (United States)

    Asakura, Masaki; Ito, Yoshihiko; Yamada, Shinzo; Yamada, Yosuke

    2017-01-01

    Abstract Yamashita, D, Asakura, M, Ito, Y, Yamada, S, and Yamada, Y. Physical characteristics and performance of Japanese top-level American football players. J Strength Cond Res 31(9): 2455–2461, 2017—This study aimed to compare the physical characteristics and performance between top-level nonprofessional football players in Japan and National Football League (NFL) Combine invited players and between top-level and middle-level players in Japan to determine the factors that enhance performance in international and national competitions. A total of 168 American football players (>20 years) in Japan participated in an anthropometric (height and weight) and physical (vertical jump, long jump, 40-yard dash, pro-agility shuttle, 3-cone drill, and bench press repetition test) measurement program based on the NFL Combine program to compete in the selection of candidates for the Senior World Championship. All players were categorized into 1 of the 3 position groups based on playing position: skill players, big skill players, and linemen. Japanese players were additionally categorized into selected and nonselected players for the second tryout. The NFL Combine candidates had significantly better performance than selected Japanese players on all variables except on performance related to quickness among the 3 position groups. Compared with nonselected players, selected Japanese skill players had better performance in the 40-yard dash and bench press test and big skill players had better performance in the vertical jump, broad jump, and 40-yard dash. Selected and nonselected Japanese linemen were not different in any measurements. These results showed the challenges in American football in Japan, which include not only improving physical performance of top-level players, but also increasing the number of football players with good physical performance. PMID:28052052

  15. EcoTRADE - a multi player network game of a tradable permit market for biodiversity credits

    CERN Document Server

    Hartig, Florian; Drechsler, Martin

    2008-01-01

    EcoTRADE is a multi player network game of a virtual biodiversity credit market. Each player controls the land use of a certain amount of parcels on a virtual landscape. The biodiversity credits of a particular parcel depend on neighboring parcels, which may be owned by other players. The game can be used to study the strategies of players in experiments or classroom games and also as a communication tool for stakeholders participating in credit markets that include spatially interdependent credits.

  16. Comparison of Speed, Agility, Anaerobic Strength and Anthropometric Characteristics in Male Football and Futsal Players

    Science.gov (United States)

    Kartal, Resat

    2016-01-01

    The purpose of this study is to compare speed, agility, anaerobic strength and some anthropometric characteristics in male football and futsal players. The sample of the study is composed of male futsal team players of Aydin Adnan Menderes University (19-24 aged) (n = 12) and Aydin Merkez Yeniköy Football Club players (19-24 aged) (n = 12). Within…

  17. High School Football Players and Their Coaches: A Qualitative Study of Their Relationships

    Science.gov (United States)

    Skaza, Robert J.

    2014-01-01

    This basic qualitative study of high school football coach-player relationships explores the players' perceptions of these relationships, specifically the perceptions the players have of how these relationships influenced their lives. This study allowed the researcher to examine the characteristics of high school football coaches as they relate to…

  18. Physical qualities and activity profiles of sub-elite and recreational Australian football players.

    Science.gov (United States)

    Stein, Josh G; Gabbett, Tim J; Townshend, Andrew D; Dawson, Brian T

    2015-11-01

    To investigate the relationship between physical qualities and match activity profiles of recreational Australian football players. Prospective cohort study. Forty players from three recreational Australian football teams (Division One, Two and Three) underwent a battery of fitness tests (vertical jump, 10 and 40 m sprint, 6 m × 30 m repeated sprint test, Yo-Yo intermittent recovery level Two and 2-km time trial). The activity profiles of competitive match-play were quantified using 10-Hz Global Positioning System units. Division One players possessed greater maximum velocity, Yo-Yo level Two and 2-km time trial performances than Division Two and Three players. In addition, Division One players covered greater relative distance, and relative distances at moderate- and high-intensities during match-play than Division Two and Three players. Division Two players had better 2-km time trial performances than Division Three players. Positive associations (P football players competing at a higher level exhibit greater physical qualities and match-play activity profiles than lesser-skilled recreational players. Acceleration and maximum velocity, 2-km time trial and Yo-Yo level Two performances discriminate between players of different playing levels, and are related to physical match performance in recreational Australian football. The development of these qualities is likely to contribute to improved match performance in recreational Australian football players. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  19. Self-Esteem Profile among the Female Futsal-Football Players at Jordanian Clubs

    Science.gov (United States)

    Khasawneh, Aman

    2015-01-01

    This study aimed at identifying the level of physical and body self-esteem among the female futsal - football players at Jordanian clubs. The sample of the study was composed of (38) female players among the Jordanian clubs' players of futsal-football who were chosen randomly out of the study community, and the self-esteem scale was used,…

  20. High School Football Players and Their Coaches: A Qualitative Study of Their Relationships

    Science.gov (United States)

    Skaza, Robert J.

    2014-01-01

    This basic qualitative study of high school football coach-player relationships explores the players' perceptions of these relationships, specifically the perceptions the players have of how these relationships influenced their lives. This study allowed the researcher to examine the characteristics of high school football coaches as they relate to…

  1. Design and Usability Testing of an Audio Platform Game for Players with Visual Impairments

    Science.gov (United States)

    Oren, Michael; Harding, Chris; Bonebright, Terri L.

    2008-01-01

    This article reports on the evaluation of a novel audio platform game that creates a spatial, interactive experience via audio cues. A pilot study with players with visual impairments, and usability testing comparing the visual and audio game versions using both sighted players and players with visual impairments, revealed that all the…

  2. Training habits and injuries of masters' level football players: a preliminary report.

    Science.gov (United States)

    Newsham-West, R; Button, C; Milburn, P D; Mündermann, A; Sole, G; Schneiders, A G; Sullivan, S J

    2009-05-01

    To profile training habits and injuries in football players participating in a national Masters tournament. A cross-sectional retrospective study design was used to survey male football players attending the 2008 New Zealand Masters Games. Information regarding player demographics, football injuries, football related training, and risk factors for injury were collected. 199 Players were recruited, with a median age of 44 yrs (range 35-73) and a median football playing history of 15 yrs (range 0-66). Irrespective of age, 112 (84%) players included a warm-up and 104 (78%) included a stretching regime in their regular training programme. In the 12 months prior to the tournament, 128 football related injuries were reported by 93 players (64 injuries/100 players or 46 injured players/100 players). The most frequently injured region was the lower limb; specifically the lower leg (n=23), ankle (n=18), hamstring (n=17), knee (n=15), and Achilles tendon (n=15). This study provides a preliminary insight into the training habits and injury profiles of Masters football players. Despite all players including some form of injury prevention strategy in their training, a significant number of players experienced an injury in the 12 months prior to the tournament.

  3. DMPD: TLR3 in antiviral immunity: key player or bystander? [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16027039 TLR3 in antiviral immunity: key player or bystander? Schroder M, Bowie AG.... Trends Immunol. 2005 Sep;26(9):462-8. (.png) (.svg) (.html) (.csml) Show TLR3 in antiviral immunity: key pl...ayer or bystander? PubmedID 16027039 Title TLR3 in antiviral immunity: key player or bystander? Authors Schr

  4. Modeling Longitudinal Changes in 5m Sprinting Performance Among Young Male Tennis Players

    NARCIS (Netherlands)

    Kramer, Tamara; Valente-Dos-Santos, Joao; Coelho-E-Silva, Manuel J.; Malina, Robert M.; Huijgen, Barbara C. H.; Smith, Joanne; Elferink-Gemser, Marije T.; Visscher, Chris

    2016-01-01

    Year-to-year changes in sprinting in youth tennis players were examined in a mixed-longitudinal study (256 male players, aged 10-15 years: 993 measurements). Height (h), body mass (BM), lower limb explosive strength (LLES), and a 5-m sprint were measured over five years. During that period, players

  5. The Ability of Elite Table Tennis Players with Intellectual Disabilities to Adapt Their Service/Return

    Science.gov (United States)

    Van Biesen, Debbie; Verellen, Joeri; Meyer, Christophe; Mactavish, Jennifer; Van de Vliet, Peter; Vanlandewijck, Yves

    2010-01-01

    In this study the ability of elite table tennis players with intellectual disability (ID) to adapt their service/return to specific ball spin characteristics was investigated. This was done by examining the performance of 39 players with ID and a reference group of 8 players without ID on a standardized table tennis specific test battery. The…

  6. Achievement Goals, Motivational Climate and Sportspersonship: A Study of Young Handball Players

    Science.gov (United States)

    Stornes, Tor; Ommundsen, Yngvar

    2004-01-01

    The aim of this study was to investigate the relationships between achievement goals, perceptions of motivational climate and sportspersonship in a sample of young male Norwegian handball players. A cross-sectional study of 440 male handball players aged from 14 to 16 was conducted, in which the players responded to a questionnaire measuring…

  7. Effect of Core Training on 16 Year-Old Soccer Players

    Science.gov (United States)

    Afyon, Yakup Akif

    2014-01-01

    Core trainings have been widely used by trainers recently in order to improve performance of soccer players. In this context, the aim of this study is to examine the effect of core training on some motoric capabilities of 16 years old soccer players. Thirty certified soccer players who were 16 years old from B.B. Bodrumspor Club in 2013-2014…

  8. Pressure at play: measuring player approach and avoidance through the keyboard

    NARCIS (Netherlands)

    Hoogen, Wouter van den; Braad, Eelco; IJsselsteijn, Wijnand

    2014-01-01

    With the increased adoption of real-time objective measurements of player experience, advances have been made in characterising the dynamically changing aspects of the player experience during gameplay itself. A direct coupling to player action, however, is not without challenges. Many physiological

  9. Pressure at play: measuring player approach and avoidance behaviour through the keyboard

    NARCIS (Netherlands)

    Hoogen, Wouter M. van den; Braad, Eelco P.; IJsselsteijn, Wijnand A.

    2014-01-01

    With the increased adoption of real-time objective measurements of player experience, advances have been made in characterising the dynamically changing aspects of the player experience during gameplay itself. A direct coupling to player action, however, is not without challenges. Many physiological

  10. Forecasting the Market for New Communication Technology: The Home Video Player Experience.

    Science.gov (United States)

    Klopfenstein, Bruce C.

    This paper describes a critical study of the available forecasts and forecasting studies for the home video player market over a 15-year period which was undertaken to discover why so many forecasts were wrong about consumer adoption of home videocassette players and videodisk players, the reasons for these errors, and ways in which this knowledge…

  11. Online and live regular poker players: Do they differ in impulsive sensation seeking and gambling practice?

    Science.gov (United States)

    Barrault, Servane; Varescon, Isabelle

    2016-03-01

    Background and aims Online gambling appears to have special features, such as anonymity, speed of play and permanent availability, which may contribute to the facilitation and increase in gambling practice, potentially leading to problem gambling. The aims of this study were to assess sociodemographic characteristics, gambling practice and impulsive sensation seeking among a population of regular poker players with different levels of gambling intensity and to compare online and live players. Methods 245 regular poker players (180 online players and 65 live players) completed online self-report scales assessing sociodemographic data, pathological gambling (SOGS), gambling practice (poker questionnaire) and impulsive sensation seeking (ImpSS). We used SOGS scores to rank players according to the intensity of their gambling practice (non-pathological gamblers, problem gamblers and pathological gamblers). Results All poker players displayed a particular sociodemographic profile: they were more likely to be young men, executives or students, mostly single and working full-time. Online players played significantly more often whereas live players reported significantly longer gambling sessions. Sensation seeking was high across all groups, whereas impulsivity significantly distinguished players according to the intensity of gambling. Discussion Our results show the specific profile of poker players. Both impulsivity and sensation seeking seem to be involved in pathological gambling, but playing different roles. Sensation seeking may determine interest in poker whereas impulsivity may be involved in pathological gambling development and maintenance. Conclusions This study opens up new research perspectives and insights into preventive and treatment actions for pathological poker players.

  12. Biomechanical study of plantar pressures during walking in male soccer players with increased vs. normal hip alpha angles.

    Science.gov (United States)

    Hagen, Marco; Abraham, Christoph; Ficklscherer, Andreas; Lahner, Matthias

    2015-01-01

    Femoroacetabular impingement (FAI) is accompanied by increased hip alpha angles, in particular in athletes with high impact sports. The aim of our study was to investigate the dynamic function of the foot during walking in male soccer players with increased versus normal alpha angles. Plantar pressures of 20 injury-free male soccer players were recorded during barefoot walking at 1.6 m/s. Ten subjects had bilaterally increased (>55°) (IA) and ten subjects normal (pressure-time-integrals (-29%; prelative loads (prelative loads are increased under the lateral midfoot (ppressure which indicates a compensatory mechanism of the foot during walking.

  13. Octonionization of three player, two strategy maximally entangled quantum games

    OpenAIRE

    Ahmed, Aden; Bleiler, Steve; Khan, Faisal Shah

    2008-01-01

    We develop an octonionic representation of the payoff function for three player, two strategy, maximally entangled quantum games in order to obtain computationally friendly version of this function. This computational capability is then exploited to analyze and potentially classify the Nash equilibria in the quantum games.

  14. Reciprocity on the hardwood: passing patterns among professional basketball players.

    Science.gov (United States)

    Willer, Robb; Sharkey, Amanda; Frey, Seth

    2012-01-01

    Past theory and research view reciprocal resource sharing as a fundamental building block of human societies. Most studies of reciprocity dynamics have focused on trading among individuals in laboratory settings. But if motivations to engage in these patterns of resource sharing are powerful, then we should observe forms of reciprocity even in highly structured group environments in which reciprocity does not clearly serve individual or group interests. To this end, we investigated whether patterns of reciprocity might emerge among teammates in professional basketball games. Using data from logs of National Basketball Association (NBA) games of the 2008-9 season, we estimated a series of conditional logistic regression models to test the impact of different factors on the probability that a given player would assist another player in scoring a basket. Our analysis found evidence for a direct reciprocity effect in which players who had "received" assists in the past tended to subsequently reciprocate their benefactors. Further, this tendency was time-dependent, with the probability of repayment highest soon after receiving an assist and declining as game time passed. We found no evidence for generalized reciprocity - a tendency to "pay forward" assists - and only very limited evidence for indirect reciprocity - a tendency to reward players who had sent others many assists. These findings highlight the power of reciprocity to shape human behavior, even in a setting characterized by extensive planning, division of labor, quick decision-making, and a focus on inter-group competition.

  15. Reciprocity on the hardwood: passing patterns among professional basketball players.

    Directory of Open Access Journals (Sweden)

    Robb Willer

    Full Text Available Past theory and research view reciprocal resource sharing as a fundamental building block of human societies. Most studies of reciprocity dynamics have focused on trading among individuals in laboratory settings. But if motivations to engage in these patterns of resource sharing are powerful, then we should observe forms of reciprocity even in highly structured group environments in which reciprocity does not clearly serve individual or group interests. To this end, we investigated whether patterns of reciprocity might emerge among teammates in professional basketball games. Using data from logs of National Basketball Association (NBA games of the 2008-9 season, we estimated a series of conditional logistic regression models to test the impact of different factors on the probability that a given player would assist another player in scoring a basket. Our analysis found evidence for a direct reciprocity effect in which players who had "received" assists in the past tended to subsequently reciprocate their benefactors. Further, this tendency was time-dependent, with the probability of repayment highest soon after receiving an assist and declining as game time passed. We found no evidence for generalized reciprocity - a tendency to "pay forward" assists - and only very limited evidence for indirect reciprocity - a tendency to reward players who had sent others many assists. These findings highlight the power of reciprocity to shape human behavior, even in a setting characterized by extensive planning, division of labor, quick decision-making, and a focus on inter-group competition.

  16. Concussion Education for High School Football Players: A Pilot Study

    Science.gov (United States)

    Manasse-Cohick, Nancy J.; Shapley, Kathy L.

    2014-01-01

    This survey study compared high school football players' knowledge and attitudes about concussion before and after receiving concussion education. There were no significant changes in the Concussion Attitude Index. Results revealed a statistically significant difference in the athletes' scores for the Concussion Knowledge Index,…

  17. LIPOSARCOMA OF THE KNEE IN A TENNIS PLAYER: CASE REPORT

    Science.gov (United States)

    Filho, Jorge Sayum; Sayum, Jorge; de Carvalho, Rogério Teixeira; Garms, Emerson; Ramos, Leonardo Addeo; Matsuda, Marcelo Mitsura; Ejnisman, Benno; Cohen, Moisés

    2015-01-01

    Liposarcoma is an uncommon malignant tumor. It originates in the mesenchymal cells, and is the most common of the soft tissue sarcomas. The authors report a case of a 40 year-old male tennis player with liposarcoma in the posterior right knee and distal thigh region. PMID:27047841

  18. Enhancing Performance & Preventing Injuries in Team Sport Players

    NARCIS (Netherlands)

    van der Does, Hendrike

    2016-01-01

    Next to physical load and recovery as a result of training, psychosocial stress and recovery affect performance and injury risk of team sport players. This can be concluded based on a series of studies that focus on the relation between jumping technique, training load, training recovery, psychosoci

  19. Adolescents risky MP3-player listening and its psychosocial correlates

    NARCIS (Netherlands)

    Vogel, Ineke; Brug, Johannes; van der Ploeg, Catharina P. B.; Raat, Hein

    2011-01-01

    Analogue to occupational noise-induced hearing loss, MP3-induced hearing loss may be evolving into a significant social and public health problem. To inform prevention strategies and interventions, this study investigated correlates of adolescents' risky MP3-player listening behavior primarily infor

  20. Active Player Modeling in the Iterated Prisoner's Dilemma.

    Science.gov (United States)

    Park, Hyunsoo; Kim, Kyung-Joong

    2016-01-01

    The iterated prisoner's dilemma (IPD) is well known within the domain of game theory. Although it is relatively simple, it can also elucidate important problems related to cooperation and trust. Generally, players can predict their opponents' actions when they are able to build a precise model of their behavior based on their game playing experience. However, it is difficult to make such predictions based on a limited number of games. The creation of a precise model requires the use of not only an appropriate learning algorithm and framework but also a good dataset. Active learning approaches have recently been introduced to machine learning communities. The approach can usually produce informative datasets with relatively little effort. Therefore, we have proposed an active modeling technique to predict the behavior of IPD players. The proposed method can model the opponent player's behavior while taking advantage of interactive game environments. This experiment used twelve representative types of players as opponents, and an observer used an active modeling algorithm to model these opponents. This observer actively collected data and modeled the opponent's behavior online. Most of our data showed that the observer was able to build, through direct actions, a more accurate model of an opponent's behavior than when the data were collected through random actions.

  1. Generic Physiological Features as Predictors of Player Experience

    DEFF Research Database (Denmark)

    Martínez, Héctor Pérez; Garbarino, Maurizio; Yannakakis, Georgios N.

    2011-01-01

    This paper examines the generality of features extracted from heart rate (HR) and skin conductance (SC) signals as predictors of self-reported player affect expressed as pairwise preferences. Artificial neural networks are trained to accurately map physiological features to expressed affect in two...

  2. Concussion Education for High School Football Players: A Pilot Study

    Science.gov (United States)

    Manasse-Cohick, Nancy J.; Shapley, Kathy L.

    2014-01-01

    This survey study compared high school football players' knowledge and attitudes about concussion before and after receiving concussion education. There were no significant changes in the Concussion Attitude Index. Results revealed a statistically significant difference in the athletes' scores for the Concussion Knowledge Index, "t"(244)…

  3. Somatotype of Competitive Youth Soccer Players From Brazil

    Directory of Open Access Journals (Sweden)

    Fidelix Yara Lucy

    2014-10-01

    Full Text Available The aim of this study was to identify the morphological configuration of youth athletes from professional soccer clubs and to verify their differences according to the tactical position on the field. Overall, 67 male players aged 15 to 17 years were evaluated. The examined anthropometric measurements included body mass, body height, skinfolds (triceps, subscapular, supraspinal and medial calf, girths (flexed and tensed arm and calf and breadths (humerus and femur. For statistical purposes, analysis of variance and post hoc Bonferroni and Kruskal-Wallis tests were used. We concluded that goalkeepers were heavier and taller than center backs (p = 0.015 and p = 0.001, midfielders (p = 0.005 and p <0.001 and center forward players (p = 0.024 and p <0.001. The average somatotype for defense, forward and goalkeeper positions was a balanced mesomorph. Midfield players showed ectomorphic-mesomorph characteristics. It was concluded that goalkeepers were characterized as being taller and heavier and that somatotype features of athletes were similar between positions, except for midfield players

  4. Monitoring load, recovery and performance in young elite soccer players

    NARCIS (Netherlands)

    Brink, Michel S.; Nederhof, Esther; Visscher, Chris; Schmikli, Sandor L.; Lemmink, Koen A. P. M.

    2010-01-01

    Brink, MS, Nederhof, E, Visscher, C, Schmikli, SL, and Lemmink, KAPM. Monitoring load, recovery, and performance in young elite soccer players. J Strength Cond Res 24(3): 597603, 2010-The purpose of this study was to investigate the relation between training load, recovery, and monthly field test pe

  5. The Development of Attention Skills in Action Video Game Players

    Science.gov (United States)

    Dye, M. W. G.; Green, C. S.; Bavelier, D.

    2009-01-01

    Previous research suggests that action video game play improves attentional resources, allowing gamers to better allocate their attention across both space and time. In order to further characterize the plastic changes resulting from playing these video games, we administered the Attentional Network Test (ANT) to action game players and…

  6. Body composition and nutritional profile of male adolescent tennis players.

    Science.gov (United States)

    Juzwiak, Claudia R; Amancio, Olga M S; Vitalle, Maria S S; Pinheiro, Marcelo M; Szejnfeld, Vera L

    2008-09-01

    In this cross-sectional study, we evaluated the body composition and dietary intake of 44 adolescent tennis players. After being divided into two groups (age 10-13 years and age 14-18), the players had their weight, height, and sexual maturation assessed. Dual-energy X-ray absorptiometry was used to assess body composition. Food intake was obtained from a non-consecutive 4-day food record. The data were analysed using the Virtual Nutri v.1.0 software and compared with the present recommendations for adolescent athletes or dietary reference intakes. Body mass index and body fat for tennis practice were adequate for 89% and 71% of the tennis players respectively, regardless of age group. A calorie deficit greater than 10% of energy expenditure was observed in 32% of the sample. Fifty percent of the athletes consumed carbohydrates in accordance with recommended values. Protein and lipid intakes were above recommended values, while fibre, calcium, potassium, magnesium, and folic acid intakes were below recommendation for 98%, 80%, 100%, 100%, and 98% of the tennis players respectively. The observed nutritional deficiencies represent an additional barrier for adolescents engaged in competitive sports to achieve an optimum nutrition to maintain growth, health, and performance.

  7. Division IAA Football Players and Risk Factors for Metabolic Syndrome

    Science.gov (United States)

    Repovich, Wendy E. S.; Babcock, Garth J.

    2012-01-01

    The purpose of this study was to determine if body composition and blood pressure (BP), two markers for Metabolic Syndrome (MetS), were correlated in college football players. Height, weight, BMI, systolic (SBP) and Diastolic (DBP) blood pressure and body composition (three measures) were assessed in a Division IAA football team (N = 55). Data…

  8. Concussion Education for High School Football Players: A Pilot Study

    Science.gov (United States)

    Manasse-Cohick, Nancy J.; Shapley, Kathy L.

    2014-01-01

    This survey study compared high school football players' knowledge and attitudes about concussion before and after receiving concussion education. There were no significant changes in the Concussion Attitude Index. Results revealed a statistically significant difference in the athletes' scores for the Concussion Knowledge Index, "t"(244)…

  9. Development of Repeated Sprint Ability in Talented Youth Basketball Players

    NARCIS (Netherlands)

    te Wierike, Sanne C. M.; de Jong, Mark C.; Tromp, Eveline J. Y.; Vuijk, Pieter J.; Lemmink, Koen A. P. M.; Malina, Robert M.; Elferink-Gemser, Marije T.; Visscher, Chris

    te Wierike, SCM, de Jong, MC, Tromp, EJY, Vuijk, PJ, Lemmink, KAPM, Malina, RM, Elferink-Gemser, MT, and Visscher, C. Development of repeated sprint ability in talented youth basketball players. J Strength Cond Res 28(4): 928-934, 2014-Factors affecting repeated sprint ability (RSA) were evaluated

  10. Not all players are equally motivated: The role of narcissism.

    Science.gov (United States)

    Roberts, Ross; Woodman, Tim; Lofthouse, Sian; Williams, Lucy

    2015-01-01

    Research on motivational climates consistently demonstrates that mastery-focused climates are associated with positive outcomes and ego-involving performance climates lead to maladaptive outcomes. However, the role of personality within such a framework has been largely ignored. To redress this imbalance, we examined the potential role of narcissism in moderating the effects of different motivational climates on leader-inspired extra effort in training. Training is where rugby players spend most of their rugby time and we were keen to examine the combination of personality and climate that might maximise the yield of such training environments. Female rugby players (n = 126) from 15 clubs completed measures of narcissism, motivational climate and effort. Moderated regression analyses revealed that narcissism moderated the relationship between motivational climate and effort. Increases in either performance or mastery climates were associated with increases in effort for narcissists; no such relationship was revealed for low narcissists. The findings demonstrate the importance of considering personality within rugby training environments, as it is clear that not every player will respond the same way to specific training conditions. Coaches who understand this and are able to tailor individualised motivational climates will likely gain the greatest benefits from their different players.

  11. Personality and Injury Risk Among ‎Professional Hockey Players

    Directory of Open Access Journals (Sweden)

    David C. Schwebel

    2009-07-01

    Full Text Available Background: Although much is known about risk for athletic injury, research on the roles of individual differences in personality and temperament on athletic injury has lagged. We hypothesized that professional athletes with high sensation-seeking and extraversion scores, and with low effortful control scores, would experience more injuries over the course of a season, would have more severe injuries, and would miss more total days of play. Methods: Prospective design with questionnaire report at time one and injury tracking throughout an 18-week athletic season. Setting: Professional hockey team in the United States. Participants: Eighteen professional hockey players (ages 21-33. Measurements: Players completed self-report personality (Sensation-Seeking Scale, Form V and temperament (the Adult Temperament Questionnaire measures. Quantity and severity of injury, as well as playing time missed, were tracked for 18 weeks. Results: On average, players experienced almost 6 injuries causing a loss of 10 playing days through the season. Those players scoring high on Boredom Susceptibility and Total Sensation-Seeking incurred more total injuries. Those scoring high on temperamental neutral perceptual sensitivity suffered more severe injuries. Conclusions: Athletes who suffered more injuries reported a preference for stimulating environments and boredom with non-stimulating environments. Injury severity was not correlated with sensation-seeking but was related to temperamental perceptual sensitivity. Implications for identification of injury-prone athletes, pre-injury training, and post-injury treatment are discussed.

  12. Manikin for assessment of MP3 player exposure

    DEFF Research Database (Denmark)

    Hammershøi, Dorte

    2007-01-01

    and adolescents in general. Even less is known about the affect on hearing, if any. With the purpose of mediating attention to the fact that music can cause hearing damage, a manikin for assessment of MP3 player exposure has been build. The manikin has an IEC 60711 simulator in one ear, a gumstix computer...

  13. Cogeneration: a winning game for the players who risk it

    Energy Technology Data Exchange (ETDEWEB)

    1985-11-01

    Cogeneration holds out the tantalizing prospect of lower utility rates and affordable energy. But the stakes are high. Now an expert player - the cogen developer - offers to negotiate the gameboard and guarantee a win to those willing to take a chance on his services.

  14. Inadequate pre-season preparation of schoolboy rugby players - a ...

    African Journals Online (AJOL)

    currently being evaluated in 25 of the 26 schools surveyed in the original study.3 ... by 471 players, an average of 1.9 concussion injuries per .... might spend a large amount of time on this and others not, ... Rugby football injunes, 1980-1983.

  15. Surveillance of injuries among Kenya Rugby Union (KRU) players ...

    African Journals Online (AJOL)

    (38.2%) and concussion (8.9%) (table4). The types of ... being linked with dangerous play. A player in KC ... that bigger body sizes are associated with higher rates of injuries (9, 15). ... football Br J Sports Med 1974; 8: 183-187. 3. Nicholl J P ...

  16. Raynaud´s phenomenon in a slap bass player

    DEFF Research Database (Denmark)

    Jepsen, Jørgen Riis; Simonsen, Jane Angel

    2016-01-01

    OBJECTIVE: Secondary Raynaud’s phenomenon is a frequent condition related to occupational exposure to local vibration but has not been described in musicians. This study aims to describe cold-induced blanching of the right second and (in particular) third digits in a 67-year-old double bass player...

  17. Role-player expectations regarding the education of nursing research

    Directory of Open Access Journals (Sweden)

    SCD Zeelie

    2003-09-01

    Full Text Available This article reports on role player expectations regarding the education of nursing research. The importance of the role player expectations are two-fold: firstly as a factor in the external environment influencing and guiding the formulation phase of the development of standards and secondly, due to the clear indications of problems regarding nursing research in the nursing profession in literature. The role player expectations were elicited using a qualitative, exploratory and contextual design. The role player population included nurse educators, nurses in managerial, clinical and research positions, students and the medical profession. The data was gathered using the naïve sketches and qualitative data analysis was done using Morse & Field’s approach (1996:103-107 in combination with Tesch’s data analysis approach as cited by Creswell (1994:154-156. Sixty initial categories were narrowed down to six final categories, which are the research learning programme, personnel, students, departmental policies, funding and support systems.

  18. Body size and composition of National Football League players.

    Science.gov (United States)

    Kraemer, William J; Torine, Jon C; Silvestre, Ricardo; French, Duncan N; Ratamess, Nicholas A; Spiering, Barry A; Hatfield, Disa L; Vingren, Jakob L; Volek, Jeff S

    2005-08-01

    The purpose of this study was to present a profile of body size and composition of National Football League (NFL) players prior to the start of the regular season. Fifty-three members of the Indianapolis Colts professional football team were measured for height, body mass, and percentage body fat using the BOD POD air-displacement plethysmography system during summer camp of the 2003 football season. These data were categorized by position for comparison with previous studies of NFL football players. The relationships observed were as follows (= represents nonsignificant; > represents p Linebackers > Running Backs = Wide Receivers = Defensive Backs. Body Mass: Offensive Line = Defensive Line > Tight Ends = Linebackers > Running Backs = Quarterbacks/ Kickers/Punters > Wide Receivers = Defensive Backs. Percentage Body Fat: Offensive Line > Defensive Line > Quarterbacks/ Kickers/Punters = Linebackers = Tight Ends > Running Backs = Wide Receivers = Defensive Backs. Comparisons to teams in the 1970s indicate that body mass has increased only for offensive and defensive linemen; however, height and body fat among player positions have not dramatically changed. Furthermore, the body mass index is not an accurate measure or representation of body fat or obesity in NFL players. These data provide a basic template for size profiles and differences among various positions and allow comparisons with other studies for changes in the NFL over the past 3 decades.

  19. Analysis of football player's motion in view of fractional calculus

    Science.gov (United States)

    Couceiro, Micael; Clemente, Filipe; Martins, Fernando

    2013-06-01

    Accurately retrieving the position of football players over time may lay the foundations for a whole series of possible new performance metrics for coaches and assistants. Despite the recent developments of automatic tracking systems, the misclassification problem (i.e., misleading a given player by another) still exists and requires human operators as final evaluators. This paper proposes an adaptive fractional calculus (FC) approach to improve the accuracy of tracking methods by estimating the position of players based on their trajectory so far. One half-time of an official football match was used to evaluate the accuracy of the proposed approach under different sampling periods of 250, 500 and 1000 ms. Moreover, the performance of the FC approach was compared with position-based and velocity-based methods. The experimental evaluation shows that the FC method presents a high classification accuracy for small sampling periods. Such results suggest that fractional dynamics may fit the trajectory of football players, thus being useful to increase the autonomy of tracking systems.

  20. Pectoralis major ruptures in professional American football players.

    Science.gov (United States)

    Tarity, T David; Garrigues, Grant E; Ciccotti, Michael G; Zooker, Chad C; Cohen, Steven B; Frederick, Robert W; Williams, Gerald R; DeLuca, Peter F; Dodson, Christopher C

    2014-09-01

    Pectoralis major injuries are an infrequent shoulder injury that can result in pain, weakness, and deformity. These injuries may occur during the course of an athletic competition, including football. The purpose of this study was to determine the incidence of pectoralis major ruptures in professional football players and time lost from the sport following injury. We hypothesized that ruptures most frequently occur during bench-press strength training. The National Football League Injury Surveillance System was reviewed for all pectoralis major injuries in all players from 2000 to 2010. Details regarding injury setting, player demographics, method of treatment, and time lost were recorded. A total of 10 injuries-complete ruptures-were identified during this period. Five of the 10 were sustained in defensive players, generally while tackling. Nine occurred during game situations, and 1 occurred during practice. Specific data pertinent to the practice injury was not available. No rupture occurred during weight lifting. Eight ruptures were treated operatively, and 2 cases did not report the method of definitive treatment. The average days lost was 111 days (range, 42-189). The incidence was 0.004 pectoralis major ruptures during the 11-year study period. Pectoralis major injuries are uncommon while playing football. In the National Football League, these injuries primarily occur not during practice or while bench pressing but rather during games. When pectoralis major ruptures do occur, they are successfully treated operatively. Surgery may allow for return to full sports participation. IV, case series.

  1. Wireless nanosensors for monitoring concussion of football players

    Science.gov (United States)

    Ramasamy, Mouli; Harbaugh, Robert E.; Varadan, Vijay K.

    2015-04-01

    Football players are more to violent impacts and injuries more than any athlete in any other sport. Concussion or mild traumatic brain injuries were one of the lesser known sports injuries until the last decade. With the advent of modern technologies in medical and engineering disciplines, people are now more aware of concussion detection and prevention. These concussions are often overlooked by football players themselves. The cumulative effect of these mild traumatic brain injuries can cause long-term residual brain dysfunctions. The principle of concussion is based the movement of the brain in the neurocranium and viscerocranium. The brain is encapsulated by the cerebrospinal fluid which acts as a protective layer for the brain. This fluid can protect the brain against minor movements, however, any rapid movements of the brain may mitigate the protective capability of the cerebrospinal fluid. In this paper, we propose a wireless health monitoring helmet that addresses the concerns of the current monitoring methods - it is non-invasive for a football player as helmet is not an additional gear, it is efficient in performance as it is equipped with EEG nanosensors and 3D accelerometer, it does not restrict the movement of the user as it wirelessly communicates to the remote monitoring station, requirement of individual monitoring stations are not required for each player as the ZigBee protocol can couple multiple transmitters with one receiver. A helmet was developed and validated according to the above mentioned parameters.

  2. Movement Demands of Elite U20 International Rugby Union Players

    Science.gov (United States)

    Drawer, Scott; Eager, Robin; Taylor, Neil; Cook, Christian

    2016-01-01

    The purpose of this study was to quantify movement demands of elite international age grade (U20) rugby union players during competitive tournament match play. Forty elite professional players from an U20 international performance squad were monitored using 10Hz global positioning systems (GPS) during 15 international tournament matches during the 2014/15 and 2015/16 seasons. Data on distances, velocities, accelerations, decelerations, high metabolic load (HML) distance and efforts, and number of sprints were derived. Data files from players who played over 60 min (n = 161) were separated firstly into Forwards and Backs, and more specifically into six positional groups; FR—Front Row (prop & hooker), SR—Second Row, BR—Back Row (Flankers & No.8), HB—Half Backs (scrum half & outside half), MF—Midfield (centres), B3 –Back Three (wings & full back) for match analysis. Analysis revealed significant differences between forwards and backs positions. Backs scored higher on all variables measured with the exception of number of moderate accelerations, decelerations (no difference). The centres covered the greatest total distance with the front row covering the least (6.51 ± 0.71 vs 4.97 ± 0.75 km, p rugby union players specific to positional roles. PMID:27055230

  3. Long-term training adaptations in elite male volleyball players.

    Science.gov (United States)

    Sheppard, Jeremy M; Newton, Robert U

    2012-08-01

    Several investigations have demonstrated differences in anthropometry, jump performance, and strength variables between developmental and elite-level volleyball players. However, within the elite level of play, the magnitude of change that can occur with training is unclear. The purpose of this investigation was to examine the anthropometric, vertical jump, and strength quality changes over 2 years in a group of national team volleyball players. Fourteen national team volleyball players (age, 23.0 ± 4.1 years; height, 1.98 ± 0.07 m; weight, 91.7 ± 7.9 kg) began and completed this study. Participants had all played international matches (representing Australia) before the examination time period and continued to do so during the international season. Anthropometry (stature, mass, and sum of 7 skinfolds), vertical jump measures (countermovement vertical jump; depth jump from 0.35 m, DJ; spike jump, SPJ, all including arm swing), and lower-body power (jump squat at body mass, and jump squat + 50% body weight, JS50) measures were tested before and at the conclusion of the investigation period. Significant (p 0.70) in the sum of 7 skinfolds reduction, SPJ, and leg extensor power. This study has demonstrated that elite male volleyball players can improve leanness and power, which contribute to improvements in vertical jump.

  4. meIRL-BC: Predicting Player Positions in Video Games

    NARCIS (Netherlands)

    Becht, I.; Bakkes, S.; Barnes, T.; Bogost, I.

    2014-01-01

    In this paper we demonstrate how behaviour-classification models can improve player position prediction for video game AI. To this end, we propose a novel method named meIRL-BC, which (1) uses maximum-entropy Inverse Reinforcement Learning for the creation of position prediction models [15], and (2)

  5. Organizational Gameplay: The Player as Designer of Character Organizations

    Directory of Open Access Journals (Sweden)

    Luciano R. Coutinho

    2015-01-01

    Full Text Available Looking at the ways in which players interact with computer games (the gameplays, we perceive predominance of character-centered and/or microcontrolled modes of interaction. Despite being well established, these gameplays tend to structure the games in terms of challenges to be fulfilled on an individual basis, or by thinking collectively but having to microcontrol several characters at the same time. From this observation, the paper presents a complementary gameplay in which the player is urged to face collective challenges by designing character organizations. The basic idea is to make the player structure and control group of characters by defining organizational specifications (i.e., definitions of roles, collective strategies, and social norms. During the game, commanded by the player, artificial agents are then instantiated to play the roles and to follow the strategies and norms as defined in the organizational specification. To turn the idea into practice, the paper proposes an abstract architecture comprising three components or layers. This architecture is materialized in a proof of concept prototype that combines the Minecraft game server, JADE agent platform, and MOISE+ organizational model. Variations and possibilities are discussed and the proposal is compared to related work in the literature.

  6. Game Play Schemas: From Player Analysis to Adaptive Game Mechanics

    Directory of Open Access Journals (Sweden)

    Craig A. Lindley

    2008-01-01

    Full Text Available Schema theory provides a foundation for the analysis of game play patterns created by players during their interaction with a game. Schema models derived from the analysis of play provide a rich explanatory framework for the cognitive processes underlying game play, as well as detailed hypotheses for the hierarchical structure of pleasures and rewards motivating players. Game engagement is accounted for as a process of schema selection or development, while immersion is explained in terms of levels of attentional demand in schema execution. However, schemas may not only be used to describe play, but might be used actively as cognitive models within a game engine. Predesigned schema models are knowledge representations constituting anticipated or desired learned cognitive outcomes of play. Automated analysis of player schemas and comparison with predesigned target schemas can provide a foundation for a game engine adapting or tuning game mechanics to achieve specific effects of engagement, immersion, and cognitive skill acquisition by players. Hence, schema models may enhance the play experience as well as provide a foundation for achieving explicitly represented pedagogical or therapeutic functions of games.

  7. Deploying music characteristics for an affective music player

    NARCIS (Netherlands)

    van der Zwaag, Marjolein D.; Westerink, Joyce H.D.M.; van den Broek, Egon; Cohn, Jeffrey; Nijholt, Antinus; Pantic, Maja

    2009-01-01

    This paper describes work toward an affective music player (AMP), which is able to direct affect to a goal state by selecting music. Repeatedly, music has been shown to modulate affect; however, precise guidelines for the use of music characteristics in an AMP have not been defined. To explore these

  8. "Badminton Player-Coach" Interactions between Failing Students

    Science.gov (United States)

    Mascret, Nicolas

    2011-01-01

    Background: Physical education teachers often use the player-coach dyad in individual opposition sports so that students can obtain information on their actions and then better regulate them. This type of work also develops methodological and social skills. However, the task of observing a partner often poses problems for failing students, who…

  9. Deploying music characteristics for an affective music player

    NARCIS (Netherlands)

    Zwaag, van der Marjolein D.; Westerink, Joyce H.D.M.; Broek, van den Egon L.; Cohn, Jeffrey; Nijholt, Anton; Pantic, Maja

    2009-01-01

    This paper describes work toward an affective music player (AMP), which is able to direct affect to a goal state by selecting music. Repeatedly, music has been shown to modulate affect; however, precise guidelines for the use of music characteristics in an AMP have not been defined. To explore these

  10. Development of Repeated Sprint Ability in Talented Youth Basketball Players

    NARCIS (Netherlands)

    te Wierike, Sanne C. M.; de Jong, Mark C.; Tromp, Eveline J. Y.; Vuijk, Pieter J.; Lemmink, Koen A. P. M.; Malina, Robert M.; Elferink-Gemser, Marije T.; Visscher, Chris

    2014-01-01

    te Wierike, SCM, de Jong, MC, Tromp, EJY, Vuijk, PJ, Lemmink, KAPM, Malina, RM, Elferink-Gemser, MT, and Visscher, C. Development of repeated sprint ability in talented youth basketball players. J Strength Cond Res 28(4): 928-934, 2014-Factors affecting repeated sprint ability (RSA) were evaluated i

  11. Hand Grip Strength Vs. Sprint Effectiveness in Amputee Soccer Players

    Directory of Open Access Journals (Sweden)

    Wieczorek Marta

    2015-12-01

    Full Text Available Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 – 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed.

  12. Computing sequential equilibria for two-player games

    DEFF Research Database (Denmark)

    Miltersen, Peter Bro

    2006-01-01

    Koller, Megiddo and von Stengel showed how to efficiently compute minimax strategies for two-player extensive-form zero-sum games with imperfect information but perfect recall using linear programming and avoiding conversion to normal form. Their algorithm has been used by AI researchers for cons...

  13. Increasing mouthguards usage among junior rugby and basketball players.

    Science.gov (United States)

    Jalleh, G; Donovan, R J; Clarkson, J; March, K; Foster, M; Giles-Corti, B

    2001-06-01

    To evaluate a Western Australian mouthguard promotion campaign, launched at the start of the 1997/98 junior rugby union and junior basketball seasons, aimed at increasing mouthguard usage at competition and training. A quasi-experimental field design was used to assess the impact of the mouthguard campaign on behavioural change. Observational data were collected pre- and post-campaign on mouthguard usage by players present at a rugby and basketball competition event and at a training session. Junior Australian Rules Football players were used as a control group. Pre-post observational surveys showed a significantly greater increase in mouthguard usage in competition games among rugby union (77% to 84%) and basketball players (23% to 43%) compared with the control group (72% to 73%). All codes showed a post-campaign increase in mouthguard usage at training, but the intervention codes' increases were greater than the control's increase (rugby union: 29% to 40%; basketball: 11% to 36%; football: 34% to 40%). The campaign had a significant and substantial effect on behaviour and provides evidence of the benefits of leveraging a sponsorship to modify the behaviour of the target group. This campaign provides a model for promoting mouthguard usage in other sports among junior players.

  14. Foot posture and patellar tendon pain among adult volleyball players

    NARCIS (Netherlands)

    Groot, R. de; Malliaras, P.; Munteanu, S.; Payne, C.; Morrissey, D.; Maffulli, N.

    2012-01-01

    OBJECTIVE: We hypothesized that individuals with a normal foot posture would be less likely to experience patellar tendon pain and pathology than those with a pronated or supinated foot. DESIGN: Observational study. SETTING: Field-based study among competing athletes. PARTICIPANTS: Volleyball player

  15. Foot Posture and Patellar Tendon Pain Among Adult Volleyball Players

    NARCIS (Netherlands)

    de Groot, Reinier; Malliaras, Peter; Munteanu, Shannon; Payne, Craig; Morrissey, Dylan; Maffulli, Nicola

    2012-01-01

    Objective: We hypothesized that individuals with a normal foot posture would be less likely to experience patellar tendon pain and pathology than those with a pronated or supinated foot. Design: Observational study. Setting: Field-based study among competing athletes. Participants: Volleyball player

  16. Older Amateur Keyboard Players Learning for Self-Fulfilment

    Science.gov (United States)

    Taylor, Angela

    2011-01-01

    This article investigates self-reported music learning experiences of 21 older amateur pianists and electronic keyboard players. Significant changes in their lives and the encouragement of friends were catalysts for returning to or taking up a keyboard instrument as an adult, although not all returners had positive memories of learning a keyboard…

  17. Older Amateur Keyboard Players Learning for Self-Fulfilment

    Science.gov (United States)

    Taylor, Angela

    2011-01-01

    This article investigates self-reported music learning experiences of 21 older amateur pianists and electronic keyboard players. Significant changes in their lives and the encouragement of friends were catalysts for returning to or taking up a keyboard instrument as an adult, although not all returners had positive memories of learning a keyboard…

  18. Development of Repeated Sprint Ability in Talented Youth Basketball Players

    NARCIS (Netherlands)

    te Wierike, Sanne C. M.; de Jong, Mark C.; Tromp, Eveline J. Y.; Vuijk, Pieter J.; Lemmink, Koen A. P. M.; Malina, Robert M.; Elferink-Gemser, Marije T.; Visscher, Chris

    2014-01-01

    te Wierike, SCM, de Jong, MC, Tromp, EJY, Vuijk, PJ, Lemmink, KAPM, Malina, RM, Elferink-Gemser, MT, and Visscher, C. Development of repeated sprint ability in talented youth basketball players. J Strength Cond Res 28(4): 928-934, 2014-Factors affecting repeated sprint ability (RSA) were evaluated i

  19. College Students' Usage of Personal Music Players (PMP) during Exercise

    Science.gov (United States)

    Barney, David; Gust, Anita; Liguori, Gary

    2012-01-01

    The purpose of this study was to investigate the use of personal music players (PMPs) during exercise, including their purpose(s), how they affect exercise, and the most common music listened to. A representative sample of 184 undergraduate students from two separate university wellness centers completed a 17-item, content validated questionnaire…

  20. Pro Football: Do Players Pay With Their Health?

    Science.gov (United States)

    Groves, D

    1989-01-01

    The hits and injuries, playing hurt, high-fat diets, and the use of anabolic-androgenic steroids may lead to serious health problems for professional football players. Are those problems an unavoidable part of the game, or can they be minimized or prevented?

  1. Different injury pattern in goalkeepers compared to field players

    DEFF Research Database (Denmark)

    Eirale, Cristiano; Tol, Johannes L; Whiteley, Rod

    2014-01-01

    Goalkeepers have a specific physiological and biomechanical profile including hip loading with increased frontal plane kinetics and explosive side jumps. The aim of this study is to analyze the injury incidence in professional goalkeepers and to compare this with field players....

  2. Computing sequential equilibria for two-player games

    DEFF Research Database (Denmark)

    Miltersen, Peter Bro

    2006-01-01

    Koller, Megiddo and von Stengel showed how to efficiently compute minimax strategies for two-player extensive-form zero-sum games with imperfect information but perfect recall using linear programming and avoiding conversion to normal form. Their algorithm has been used by AI researchers for cons...

  3. Medium-term Mortality of Dutch Professional Soccer Players

    NARCIS (Netherlands)

    Koning, Ruud H.; Amelink, Remko

    Professional athletes such as soccer players are expected to be in better health than the average member of their age cohort, if only because of the very demands imposed on them by their profession. Moreover, during their active career, their health is monitored on a regular basis. However, whenever

  4. Aerobic Development of Elite Youth Ice Hockey Players.

    Science.gov (United States)

    Leiter, Jeff R; Cordingley, Dean M; MacDonald, Peter B

    2015-11-01

    Ice hockey is a physiologically complex sport requiring aerobic and anaerobic energy metabolism. College and professional teams often test aerobic fitness; however, there is a paucity of information regarding aerobic fitness of elite youth players. Without this knowledge, training of youth athletes to meet the standards of older age groups and higher levels of hockey may be random, inefficient, and or effective. Therefore, the purpose of this study was to determine the aerobic fitness of elite youth hockey players. A retrospective database review was performed for 200 male AAA hockey players between the ages of 13 and 17 (age, 14.4 ± 1.2 years; height, 174.3 ± 8.5 cm; body mass, 67.2 ± 11.5 kg; body fat, 9.8 ± 3.5%) before the 2012-13 season. All subjects performed a graded exercise test on a cycle ergometer, whereas expired air was collected by either a Parvo Medics TrueOne 2400 or a CareFusion Oxycon Mobile metabolic cart to determine maximal oxygen consumption (V[Combining Dot Above]O2max). Body mass, absolute V[Combining Dot Above]O2max, and the power output achieved during the last completed stage increased in successive age groups from age 13 to 15 years (p ≤ 0.05). Ventilatory threshold (VT) expressed as a percentage of V[Combining Dot Above]O2max and the heart rate (HR) at which VT occurred decreased between the ages of 13 and 14 years (p ≤ 0.05), whereas the V[Combining Dot Above]O2 at which VT occurred increased from the age of 14-15 years. There were no changes in relative V[Combining Dot Above]O2max or HRmax between any successive age groups. The aerobic fitness levels of elite youth ice hockey players increased as players age and mature physically and physiologically. However, aerobic fitness increased to a lesser extent at older ages. This information has the potential to influence off-season training and maximize the aerobic fitness of elite amateur hockey players, so that these players can meet standards set by advanced elite age groups.

  5. Abdominal body composition differences in NFL football players.

    Science.gov (United States)

    Bosch, Tyler A; Burruss, T Pepper; Weir, Nate L; Fielding, Kurt A; Engel, Bryan E; Weston, Todd D; Dengel, Donald R

    2014-12-01

    The purpose of this study was to examine visceral fat mass as well as other measures abdominal body composition in National Football League (NFL) players before the start of the season. Three hundred and seventy NFL football players were measured before the start of the season using dual-energy x-ray absorptiometry. Regional fat and lean mass was measured for each player. Players were categorized into 3 groups based on positions that mirror each other: linemen; linebackers/tight ends/running backs and wide receivers/defensive backs. Significant differences were observed between the position groups for both lean and fat regional measurements. However, the magnitude of difference was much greater for fat measures than lean measures. Additionally, a threshold was observed (∼114 kg) at which there is a greater increase in fat accumulation than lean mass accumulation. The increase in fat accumulation is distributed to the abdominal region where thresholds were observed for subcutaneous abdominal fat accumulation (12.1% body fat) and visceral abdominal fat accumulation (20.1% body fat), which likely explains the regional fat differences between groups. The results of this study suggest that as players get larger, there is more total fat than total lean mass accumulation and more fat is distributed to the abdominal region. This is of importance as increased fat mass may be detrimental to performance at certain positions. The thresholds observed for increased abdominal fat accumulation should be monitored closely given recent research observed that abdominal obesity predicts lower extremity injury risk and visceral adipose tissue's established association with cardiometabolic risk.

  6. Concussion Frequency Associates with Musculoskeletal Injury in Retired NFL Players.

    Science.gov (United States)

    Pietrosimone, Brian; Golightly, Yvonne M; Mihalik, Jason P; Guskiewicz, Kevin M

    2015-11-01

    Concussion is commonly associated with immediate and persistent alterations in motor function affecting postural control and gait. Patients with lower extremity joint injury have demonstrated functional alterations in the cerebral cortex, suggesting that musculoskeletal injury may be linked to alterations in brain function. Therefore, we examined the associations between concussion frequency and lower extremity musculoskeletal injury sustained during professional careers of National Football League (NFL) players in a cross-sectional study. An inclusive health history survey was mailed to 3647 NFL players who retired during 1930-2001. Respondents reported total concussion frequency (zero, one, two, or three or more) and presence (yes/no) of specific knee and ankle musculoskeletal injury during their NFL career. Separate logistic regression models were used to estimate associations between concussion frequency and each musculoskeletal injury type, adjusting for number of years played in the NFL, body mass index while playing in the NFL, and playing position. Data from 2429 players (66.6% response rate) were available for analysis. Nearly 61% reported experiencing a concussion while competing in the NFL. Meniscal tear was the most commonly reported musculoskeletal injury (32%). Compared with NFL players who did not sustain a concussion, retired NFL players with one, two, or three or more concussions had between 18% and 63%, 15% and 126%, and 73% and 165% higher odds of reporting various musculoskeletal injuries, respectively. A history of concussions was associated with a history of musculoskeletal injuries during NFL careers. These data suggest that a higher number of concussions is linked with higher odds of reporting a musculoskeletal injury.

  7. Sprint, agility, strength and endurance capacity in wheelchair basketball players

    Directory of Open Access Journals (Sweden)

    Javier Yanci

    2014-11-01

    Full Text Available The aims of the present study were, firstly, to determine the reliability and reproducibility of an agility T-test and Yo-Yo 10 m recovery test; and secondly, to analyse the physical characteristics measured by sprint, agility, strength and endurance field tests in wheelchair basketball (WB players. 16 WB players (33.06 ± 7.36 years, 71.89 ± 21.71 kg and sitting body height 86.07 ± 6.82 cm belonging to the national WB league participated in this study. Wheelchair sprint (5 and 20 m without ball, and 5 and 20 m with ball agility (T-test and pick-up test strength (handgrip and maximal pass and endurance (Yo-Yo 10 m recovery test were performed. T-test and Yo-Yo 10 m recovery test showed good reproducibility values (intraclass correlation coefficient, ICC = 0.74-0.94. The WB players’ results in 5 and 20 m sprints without a ball were 1.87 ± 0.21 s and 5.70 ± 0.43 s and with a ball 2.10 ± 0.30 s and 6.59 ± 0.61 s, being better than those reported in the literature. Regarding the pick-up test results (16.05 ± 0.52 s and maximal pass (8.39 ± 1.77 m, players showed worse values than those obtained in elite players. The main contribution of the present study is the characterization of the physical performance profile of WB players using a field test battery. Furthermore, we demonstrated that the agility T-test and the aerobic Yo-Yo 10 m recovery test are reliable; consequently they may be appropriate instruments for measuring physical fitness in WB.

  8. Aerobic fitness and performance in elite female futsal players

    Directory of Open Access Journals (Sweden)

    JC Barbero-Alvarez

    2016-01-01

    Full Text Available Despite its growing popularity, few studies have investigated specific physiological demands for elite female futsal. The aim of this study was to determine aerobic fitness in elite female futsal players using laboratory and field testing. Fourteen female futsal players from the Venezuelan National team (age =21.2±4.0 years; body mass =58.6±5.6 kg; height =161±5.0 cm performed a progressive maximal treadmill test under laboratory conditions. Players also performed a progressive intermittent futsal-specific field test for endurance, the Futsal Intermittent Endurance Test (FIET, until volitional fatigue. Outcome variables were exercise heart rate (HR, VO2, post-exercise blood lactate concentrations ([La]b and running speeds (km • h -2 . During the treadmill test, VO2max, maximal aerobic speed (MAS, HR and peak [La]b were 45.3±5.6 ml • kg-1 • min-1, 12.5±1.77 km • h -2 , 197±8 beats • min-1 and 11.3±1.4 mmol • l-1, respectively. The FIET total distance, peak running velocity, peak HR and [La]b were 1125.0±121.0 m, 15.2±0.5 km • h -2 , 199±8 beats • min-1 and 2.5±2.2 mmol • l-1, respectively. The FIET distance and peak speed were strongly associated (r= 0.85-87, p<0.0001 with VO2max and MAS, respectively. Peak HR and [La]b were not significantly different between tests. Elite female futsal players possess moderate aerobic fitness. Furthermore, the FIET can be considered as a valid field test to determine aerobic fitness in elite level female futsal players.

  9. Athletic Cardiac Remodeling in US Professional Basketball Players.

    Science.gov (United States)

    Engel, David J; Schwartz, Allan; Homma, Shunichi

    2016-04-01

    The incidence of sudden cardiac death is higher in US basketball players compared with other athlete groups. However, the recognition of the risk for sudden cardiac death among basketball players is challenging because little is known regarding athletic cardiac remodeling in these athletes or athletes of similarly increased size. To perform a comprehensive cardiac structural analysis of National Basketball Association (NBA) professional athletes. Echocardiographic observational study of NBA players on the active rosters for the 2013-2014 and 2014-2015 seasons was performed from December 16, 2013, to December 12, 2014. The policy of the NBA mandates annual preseason stress echocardiograms for each player. The NBA has sanctioned Columbia University Medical Center to conduct annual health and safety reviews of these echocardiograms. Data were analyzed from January to May 2015. Cardiac variables assessed included left ventricular (LV) size, mass, wall thickness, and hypertrophy patterns and function; left atrial volume; and aortic root diameter. All dimensions were biometrically scaled. Of the 526 athletes included in the study, 406 (77.2%) were African American and 107 (20.3%) were white, with a mean (SD) age of 25.7 (4.3) years. Mean (SD) athlete height was 200.2 (8.8) cm; mean body surface area, 2.38 (0.19) m2. Left ventricular size and mass in NBA athletes were proportional to body size, extending to the uppermost biometrics of the cohort. Left ventricular hypertrophy was present in 144 athletes (27.4%). African American athletes had increased LV wall thickness (unadjusted mean, 11.2 mm; 95% CI, 11.1-11.3 mm) and LV mass (unadjusted mean, 106.3 g/m2; 95% CI, 104.6-108.0 g/m2) compared with LV wall thickness (unadjusted mean, 10.5 mm; 95% CI, 10.3-10.7 mm; P basketball players and the athletic community at large.

  10. Attributes of top elite team-handball players.

    Science.gov (United States)

    Massuça, Luís M; Fragoso, Isabel; Teles, Júlia

    2014-01-01

    Researchers in the field of excellence in sport performance are becoming increasingly focused on the study of sport-specific characteristics and requirements. In accordance with this, the purposes of this study were (a) to examine the morphologic-, fitness-, handball-specific skills and psychological and "biosocial" differences between top elite and nontop elite team-handball players and (b) to investigate the extent to which they may be used to identify top elite team-handball players. One hundred sixty-seven adult male team-handball players were studied and divided in 2 groups: top elite (n = 41) and nontop elite (n = 126). Twenty-eight morphologic-, 9 fitness-, 1 handball-specific skills and 2 psychological-based and 2 "biosocial"-based attributes were used. Top elite and nontop elite groups were compared for each variable of interest using Student's t-test, and 5 logistic regression analyses were performed with the athlete's performance group (top elite or nontop elite) as the dependent variable and the variables of each category as predictors. The results showed that (a) body mass, waist girth, radiale-dactylion length, midstylion-dactylion length, and absolute muscle mass (morphologic model); (b) 30-m sprint time, countermovement jump height and average power, abdominal strength and the class of performance in the Yo-Yo Intermittent Endurance Test (fitness model); (c) offensive power (specific-skills model); (d) ego-based motivational orientation (psychological model); (e) socioeconomic status and the energy spent (for week) in handball activity (biosocial model); significantly (p handball player. Moreover, the fitness model exhibited higher percentages of correct classification (i.e., 91.5%) than all the other models did. This study provided (a) the rational to reduce the battery of tests for evaluation purposes, and (b) the initial step to work on building a multidisciplinary model to predict the probability of a handball athlete to be a top elite player.

  11. Aerobic fitness and performance in elite female futsal players

    Science.gov (United States)

    Subiela, JV; Granda-Vera, J; Castagna, C; Gómez, M; Del Coso, J

    2015-01-01

    Despite its growing popularity, few studies have investigated specific physiological demands for elite female futsal. The aim of this study was to determine aerobic fitness in elite female futsal players using laboratory and field testing. Fourteen female futsal players from the Venezuelan National team (age =21.2±4.0 years; body mass =58.6±5.6 kg; height =161±5.0 cm) performed a progressive maximal treadmill test under laboratory conditions. Players also performed a progressive intermittent futsal-specific field test for endurance, the Futsal Intermittent Endurance Test (FIET), until volitional fatigue. Outcome variables were exercise heart rate (HR), VO2, post-exercise blood lactate concentrations ([La]b) and running speeds (km · h-1). During the treadmill test, VO2max, maximal aerobic speed (MAS), HR and peak [La]b were 45.3±5.6 ml · kg-1 · min-1, 12.5±1.77 km · h-1, 197±8 beats · min-1 and 11.3±1.4 mmol · l-1, respectively. The FIET total distance, peak running velocity, peak HR and [La]b were 1125.0±121.0 m, 15.2±0.5 km · h-1, 199±8 beats · min-1 and 12.5±2.2 mmol · l-1, respectively. The FIET distance and peak speed were strongly associated (r= 0.85-87, p < 0.0001) with VO2max and MAS, respectively. Peak HR and [La]b were not significantly different between tests. Elite female futsal players possess moderate aerobic fitness. Furthermore, the FIET can be considered as a valid field test to determine aerobic fitness in elite level female futsal players. PMID:28479664

  12. Variation in the Ace Gene in Elite Polish Football Players

    Directory of Open Access Journals (Sweden)

    Cięszczyk Paweł

    2016-12-01

    Full Text Available Purpose. A common polymorphism in the angiotensin converting enzyme I gene (the ACE I/D variant represents one of the first characterized and the most widely studied genetic variants in the context of elite athletes status and performance related traits. The aim of the study was to determine the genotype and allele distribution of the allele and genotype of the ACE gene in Polish male football players. Methods. The total of 106 Polish male professional football players were recruited. They were divided into groups according to the position in the field: forwards, defenders, midfielders, and goalkeepers. For controls, samples were prepared with 115 unrelated volunteers. DNA was extracted from the buccal cells donated by the subjects, and the PCR amplification of the polymorphic region of the ACE gene containing either the insertion (I or deletion (D fragment was performed. Results. The genotype distribution and allele frequencies among all football players did not differ significantly when compared with sedentary control individuals (p = 0.887, p = 0.999, respectively. Likewise, the analysis of forwards, defenders, midfielders, and goalkeepers revealed no significant differences in either ACE genotype or allele frequencies. Conclusions. We did not provide evidence for difference of variation of the ACE I/D polymorphism between Polish football players and controls, as we did not obtain any statistically significantly higher frequency of either of the analysed alleles (I and D or genotypes (DD, ID, and II in the studied subgroups. It may be suspected that harbouring of I/D allelic variants of the ACE gene neither decreases nor increases the probability of being a professional football player in Poland.

  13. Physical Characteristics Of Female Basketball Players According To Playing Position

    Directory of Open Access Journals (Sweden)

    Kucsa Richard

    2015-05-01

    Full Text Available Physical characteristics play an important role in the selection of young basketball players and the progress in their playing performance. The aim of the study was to analyze differences in chosen physical characteristics of Slovak U17 female basketball players with respect to their playing positions. We assumed, that there will be statistically significant differences between playing positions in each performance tests results. Chosen characteristics were analyzed for 14 players (mean/SD, age 16.34±0.82; body height 179.72±8.04 cm; body weight 67.62±7.10 kg; body fat 16.59±2.04 %; VO2max 46.20±4.71 ml.kg−1.min−1 according to their playing positions (guard, forward, center. Five specific performance tests for each player were conducted as a 3/4 Basketball court sprint, 10 × 5m Shuttle test, Lane agility drill, No-step vertical jump and Maximum vertical jump. The differences in tests results by playing positions were evaluated by one-way ANOVA. There were no significant differences found in results of chosen performance tests between playing positions (p>.05. In spite of fact, that there were no significant differences, we found interesting results between playing positions in physical characteristics. Guards had better results in speed (3.73±0.16 s, quickness (17.43±0.56 s and both lower-body power tests (47.16±3.06 cm; 57.00±3.40 cm than forwards and centers. Forwards had the best results in agility test (12.54±0.43 s. The results of this study produce useful information about physical characteristics of young basketball players according to their playing position and help to diagnose and improve their performance.

  14. Soccer Players Cultural Capital and Its Impact on Migration

    Science.gov (United States)

    Leskošek, Bojan; Vodičar, Janez; Topič, Mojca Doupona

    2016-01-01

    Abstract The purpose of this study was to identify factors that constituted the cultural capital among soccer players. We assumed that in the increasingly globalized world of professional soccer, a player’s success would often depend on migrating and adjusting to life in other countries. Willingness to migrate and successful adjustment are tied to player’s previous attitudes and/or behaviours (habitus), significant support from others, including family members, and previous experiences and success in sports and education. Our hypothesised model of the cultural capital was based on the Pierre Bourdieu’s theoretical framework. It consisted of 26 variables related to three sets of factors: soccer experiences, a family context and support, and educational achievements of the players and their parents. The model was tested using a sample of 79 current soccer coaches who also had been players at the elite level. A factor analysis was used to empirically verify the content of the hypothetical model of the soccer players’ cultural capital. Nine latent factors were extracted and together, they accounted for 55.01% of the total model variance. Individual factors obtained showed a sufficient level of substantial connection. The Cronbach’s alpha value of 0.77 confirmed the internal consistency of the operationalised variables in the hypothetical model. In addition, the impact of these aforementioned life dimensions on the migration of soccer players was studied. The results of the binary logistic regression analysis showed that the first factor of the hypothetical model (F1) had 2.2 times and the second factor (F8) had 3.9 times higher odds for migration abroad. Sociocultural findings using this new assessment approach could help create better “success conditions” in the talent development of young players. PMID:28031770

  15. Development of muscular imbalance in the shoulder girdle in volleyball players

    OpenAIRE

    VRBOVÁ, Lucie

    2011-01-01

    This bachelor?s thesis deals with the development of muscular imbalance in the shoulder girdle in volleyball players. The volleyball player?s shoulder is the most exposed and vulnerable joint. In addition, the way the sport has developed, the pressure on this joint has grown. Shoulder pain limits the player?s most important move: the strength and the power of the smash and the smash serve. This thesis consists of two parts: theoretical and a practical. The theoretical part deals with the anat...

  16. Locomotion Characteristics and Match-Induced Impairments in Physical Performance in Male Elite Team Handball Players

    DEFF Research Database (Denmark)

    Michalsik, L B; Aagaard, Peter; Madsen, Klavs

    2013-01-01

    The purpose of this study was to determine the physical demands and match-induced impairments in physical performance in male elite Team Handball (TH) players in relation to playing position. Male elite TH field players were closely observed during 6 competitive seasons. Each player (wing players......: WP, pivots: PV, backcourt players: BP) was evaluated during match-play using video recording and subsequently performing locomotion match analysis. A total distance of 3 627±568 m (group means±SD) was covered per match with a total effective playing time (TPT) of 53:51±5:52 min:s, while full...

  17. Protective equipment and player characteristics associated with the incidence of sport-related concussion in high school football players: a multifactorial prospective study.

    Science.gov (United States)

    McGuine, Timothy A; Hetzel, Scott; McCrea, Michael; Brooks, M Alison

    2014-10-01

    The incidence of sport-related concussion (SRC) in high school football is well documented. However, limited prospective data are available regarding how player characteristics and protective equipment affect the incidence of SRC. To determine whether the type of protective equipment (helmet and mouth guard) and player characteristics affect the incidence of SRC in high school football players. Cohort study; Level of evidence, 2. Certified athletic trainers (ATs) at each high school recorded the type of helmet worn (brand, model, purchase year, and recondition status) by each player as well as information regarding players' demographics, type of mouth guard used, and history of SRC. The ATs also recorded the incidence and days lost from participation for each SRC. Incidence of SRC was compared for various helmets, type of mouth guard, history of SRC, and player demographics. A total of 2081 players (grades 9-12) enrolled during the 2012 and/or 2013 football seasons (2287 player-seasons) and participated in 134,437 football (practice or competition) exposures. Of these players, 206 (9%) sustained a total of 211 SRCs (1.56/1000 exposures). There was no difference in the incidence of SRC (number of helmets, % SRC [95% CI]) for players wearing Riddell (1171, 9.1% [7.6%-11.0%]), Schutt (680, 8.7% [6.7%-11.1%]), or Xenith (436, 9.2% [6.7%-12.4%]) helmets. Helmet age and recondition status did not affect the incidence of SRC. The rate of SRC (hazard ratio [HR]) was higher in players who wore a custom mouth guard (HR = 1.69 [95% CI, 1.20-2.37], P football players. Players who had sustained an SRC within the previous 12 months were more likely to sustain an SRC than were players without a history of SRC. Sports medicine providers who work with high school football players need to realize that factors other than the type of protective equipment worn affect the risk of SRC in high school players. © 2014 The Author(s).

  18. Comparison of some physical and physiologic properties of soccer players and badminton players of 10-12 years old group

    Directory of Open Access Journals (Sweden)

    Recep Kürkçü

    2009-03-01

    Full Text Available The purpose of this study is aimed to compare some physical characteristics and physiological characteristics of adult footballer and badminton players. The subjects of the study were footballer (18 boys and were badminton players (12 boys who were volunteer at primary school in Şanlıurfa. The volunteers', took part in this study, age, height and the body weight average is determined like this respectively:  Footballers: 11,77 ± 0,54 yıl, 151,40 ± 7,35 cm, 41,83 ± 10,27 kgBadminton players: ise11,58 ± 0,66 yıl, 147,37 ± 8,05 cm, 39,08 ± 9,56 kg    Systolic and diastolic blood pressure, VC, FVC, FEV1 sit-reach 30 meters sprint and left-right hand gripping strength of subjects were measured. The differences between findings which were obtained by measurements from footballers and badminton players were considered with using "t-test" on SPSS Windows 11.     According to the data, differences between age, height, body weight average, diastolic blood pressure VC, FVC, FEV1, sit-reach 30 meters sprint and left hand gripping strength were obtained pointless, in the mean time relaxing heart rate, and sit-reach test (P<0.01, systolic blood pressure and right hand gripping strength values were obtained purposeful on (P<0.05 level.     In conclusion,  physical and physiological characteristics of footballers and badminton players were affected by their sport branch furthermore, relaxing heart rate, systolic blood pressure, sit -reach 30 meters sprint, right hand gripping strength performance of footballers were obtained preferable.

  19. ASSESSMENT OF ANAEROBIC THRESHOLD IN FOOTBALL PLAYERS ON DIFFERENT POSITIONS, USING THE CONCONI TEST

    Directory of Open Access Journals (Sweden)

    Milan Cvetković

    2014-06-01

    Full Text Available Introduction: Requirements and needs of properly programmed training process, especially in the pre-season, look for a precise definition of the functional parameters of all the players. The level of anaerobic threshold, as well as research on the same, may be a good indicator of proper dosage of loading. The aim of the research is to determine the differences in running speed and heart rate at the level of anaerobic threshold in relation to the position of the player. Methods: Age of the respondents in this study included boys from 14 to 16 years of age (60 football players. The sample of respondents was divided according to playing position, as follows: center-backs (12 players, wing-backs (15 players, midfielders (14 players, forwarders (13 players and goalkeepers (6 goalkeepers. An estimation of maximum heart rate and anaerobic threshold was performed using the Conconi test – (Conconi et al. 1996. Prior to testing players had ten minutes to warm up and after a few minutes of rest the testing began. Players started with jogging test (10 km/h and after every 200 m running speed was increased by 0.5 km/h. Within certain sections the load is constant which is achieved by increasing speed after each 200 m, and then maintaining that speed until the end of the section. After processing the results within the particular software (“Polar Precision Performance SW” the values needed for this research were collected. Multivariate methods MANOVA and discriminant analysis will be applied in the paper. Regarding the univariate procedures, ANOVA t-test and Roy’s test shall be applied. The descriptive parameters, mean value, standard deviation (SD, minimum and maximum of all values, the coefficient of variation (CV of confidence intervals, skewness as the measures of asymmetry, kurtosis as the measure of flatness and the value of the Kolmogorov-Smirnov test, shall be presented. Results: By using the multivariate analysis of variance and based on the

  20. Performance following a first professional concussion among National Basketball Association players.

    Science.gov (United States)

    Yengo-Kahn, Aaron M; Zuckerman, Scott L; Stotts, Jeff; Zalneraitis, Brian H; Gardner, Ryan M; Kerr, Zachary Y; Solomon, Gary S

    2016-09-01

    Basketball is a physical game played on a hardwood floor among high-jumping athletes at risk for injury. It is currently unknown how sport-related concussion (SRC) affects player performance after injury among professional basketball players. The objective of this study was to explore the impact of SRC on basketball performance among National Basketball Association (NBA) players. A retrospective, archival cohort study was performed that compared NBA player performance following concussion to pre-concussive performance. A comprehensive NBA injury database, compiled from publically available sources, was queried for NBA players who suffered concussion from 2005-06 to 2014-15 (10 seasons). Intra-and inter-player analyses were performed against a matched control group of players who missed playing time for personal reasons. Following application of inclusion/exclusion criteria and a matching process, 51 concussed players and 51 control players were included in analysis. There were no statistically significant decrements in baseline to post-concussion performance metrics in intra-player or player vs. controls after 5 return games. Our findings suggest that at the NBA level, an athlete's performance in the initial 5 games following injury does not suffer from the after-effects of concussive injury. These results may be useful in counseling professional athletes following a concussion.

  1. The role of community in the development of elite handball and football players in Denmark.

    Science.gov (United States)

    Rossing, N N; Nielsen, A B; Elbe, A-M; Karbing, D S

    2016-01-01

    The primary purpose of this study was to investigate the effect of the place of early development in a sample of Danish male elite and youth handball and football players. The sample included 366 handball and football players from the elite Danish league in the season 2011-2012 and a comparison sample of youth players under the age of 12 from 2003, including 147,221 football and 26,290 handball players. Odds ratio analysis showed that both population size and density significantly affected the proportional number of youth players per community and the odds of athletes reaching an elite level in football and handball. The odds for youth player registrations in both handball and football increased in rural in contrast to urban communities. However, elite football players primarily came from communities of high density (>1000 pop./km(2)), whereas elite handball players primarily came from less densely populated communities (100 to <250 pop./km(2)). Furthermore, there seems to be a relation between representation of elite and talent clubs in different communities and the probability of becoming an elite player in both sports. The limited number of elite players in both sports from rural communities may be due to national talent development strategies that do not incorporate development support for clubs in rural areas. Additionally, the results of the study clearly suggest the need to include the youth player population to advance research findings in birthplace effect studies.

  2. EXAMINATION OF THE RELATIONSHIP BETWEEN OCCUPATIONAL BURNOUT AND JOB SATISFACTION OF PROFESSIONAL FOOTBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Hakkı

    2014-04-01

    Full Text Available The aim of the study is to examine the relationship between occupational burnout and job satisfaction levels of professional football players. Data was collected in 2011–2012 football seasons. 79 players from Turkey's Super League, 90 players from first, 135 football players from second and 112 football players from third division; totally 416 football players participated. “Burnout Inventory" with 22 items, developed by Maslach (1981 and adapted to Turkish by Ergin (1992 was used. Minnesota Satisfaction Questionnaire 20 "- Short Form” developed by Weiss et al (1967 and adapted to Turkish by Baycan (1985 was used. SPSS was used for the analysis of the data. Super League football players general job satisfaction levels were significantly higher than 2nd and 3rd division football players. The burnout levels of Super League football players were significantly lower than the others. The occupation burnout and job satisfaction levels of football players have a negative relationship mutually ; while job satisfaction level increased, burnout levels of players reduced. Most remarkable part is that Midfielders have lower external satisfaction than goalkeepers.

  3. Adaptivity to Age, Gender, and Gaming Platform Topology in Physical Multi-Player Games

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Friðriksson, Rafn Vídalín; Björnsson, Davíð Þór

    2012-01-01

    In games where players are competing against each other, it can be of interest to ensure that all players are challenged according to their individual skills. In order to investigate such adaptivity to the individual player in physical multi-player games, we developed a game on modular interactive...... tiles which can be used in both single-player and multi-player mode. We implemented simple adaptivity methods and tested these with different user groups including children and adults of both genders. The results show statistically significant differences in the game interactions between children...... and adults, and between male and female players. Also, results show statistically significant differences in the game interactions between different physical set-ups of the modular interactive tiles, i.e. the interaction depended on the topology of the modular tiles set-up. Changing the physical set...

  4. How do clarinet players adjust the resonances of their vocal tracts for different playing effects?

    Science.gov (United States)

    Fritz, Claudia; Wolfe, Joe

    2005-11-01

    In a simple model, the reed of the clarinet is mechanically loaded by the series combination of the acoustical impedances of the instrument itself and of the player's airway. Here we measure the complex impedance spectrum of players' airways using an impedance head adapted to fit inside a clarinet mouthpiece. A direct current shunt with high acoustical resistance allows players to blow normally, so the players can simulate the tract condition under playing conditions. The reproducibility of the results suggest that the players' ``muscle memory'' is reliable for this task. Most players use a single, highly stable vocal tract configuration over most of the playing range, except for the altissimo register. However, this ``normal'' configuration varies substantially among musicians. All musicians change the configuration, often drastically for ``special effects'' such as glissandi and slurs: the tongue is lowered and the impedance magnitude reduced when the player intends to lower the pitch or to slur downwards, and vice versa.

  5. How do clarinet players adjust the resonances of their vocal tracts for different playing effects

    CERN Document Server

    Fritz, C; Fritz, Claudia; Wolfe, Joe

    2005-01-01

    In a simple model, the reed of the clarinet is mechanically loaded by the series combination of the acoustical impedances of the instrument itself and of the player's vocal tract. Here we measure the complex impedance spectrum of players' tracts using an impedance head adapted to fit inside a clarinet mouthpiece. A direct current shunt with high acoustical resistance allows players to blow normally, so the players can simulate the tract condition under playing conditions. The reproducibility of the results suggest that the players' "muscle memory" is reliable for this task. Most players use a single, highly stable vocal tract configuration over most of the playing range, except for the altissimo register. However, this 'normal' configuration varies substantially among musicians. All musicians change the configuration, often drastically for "special effects'' such as glissandi and slurs: the tongue is lowered and the impedance magnitude reduced when the player intends to lower the pitch or to slur downwards, a...

  6. MRI findings in soccer players with long-standing adductor-related groin pain and asymptomatic controls

    DEFF Research Database (Denmark)

    Branci, Sonia; Thorborg, Kristian; Bech, Birthe Højlund

    2015-01-01

    soccer players displayed different positive MRI findings, and asymptomatic soccer players had significantly higher odds (OR ranging from 6.3 to 13.3) for BMO, adductor tendinopathy and degenerative changes than non-soccer players. CONCLUSIONS: ARGP in soccer players was associated with central disc...

  7. Relations of competitive state anxiety and efficacy of young volleyball players.

    Science.gov (United States)

    Milavić, Boris; Jurko, Damir; Grgantov, Zoran

    2013-05-01

    With the aim of validating the Competitive State Anxiety Inventory on a population of young Croatian volleyball players, 286 examinees, 106 male and 180 female volleyball players (average age of 16.09+/-1.83), filled out the CSAI-2, constructed by Martens, Vealey, Burton, Bump and Smith (1990)1. Given the fact that all scales of the Competitive State Anxiety Inventory have good homogeneity, reliability and sensitivity, it can be concluded that they represent high-quality measuring instruments for measuring psychological characteristics of young volleyball players. Young male and female volleyball players generally have a moderate level of self-confidence, and their cognitive anxiety is more prominent that somatic anxiety. In order to determine the age and gender differences in somatic and cognitive anxiety and self-confidence, parametric analysis of differences was performed and coefficients of the independent samples t-test were calculated. By analysis of differences according to age, it has been established that female junior players, in relation to female youth players, express a significantly lower level of somatic and cognitive anxiety and a significantly higher level of self-confidence. As opposed to female players, male youth and junior players do not differ in any of the analysed variables. By analysis of differences according to gender, it has been established that male youth players have a significantly higher level of self-confidence in comparison to female youth players. No significant differences were found in the level of competitive anxiety and self-confidence by analysis of variance between different player roles. No significant differences were found by discriminant analysis in somatic and cognitive anxiety, and self-confidence of female volleyball players of different situational efficacy. The group of least efficient male volleyball players is characterized by a very low level of self-confidence, while the most efficient group of volleyball

  8. Managing player load in professional rugby union: a review of current knowledge and practices.

    Science.gov (United States)

    Quarrie, Kenneth L; Raftery, Martin; Blackie, Josh; Cook, Christian J; Fuller, Colin W; Gabbett, Tim J; Gray, Andrew J; Gill, Nicholas; Hennessy, Liam; Kemp, Simon; Lambert, Mike; Nichol, Rob; Mellalieu, Stephen D; Piscione, Julien; Stadelmann, Jörg; Tucker, Ross

    2017-03-01

    The loads to which professional rugby players are subjected has been identified as a concern by coaches, players and administrators. In November 2014, World Rugby commissioned an expert group to identify the physical demands and non-physical load issues associated with participation in professional rugby. To describe the current state of knowledge about the loads encountered by professional rugby players and the implications for their physical and mental health. The group defined 'load' as it relates to professional rugby players as the total stressors and demands applied to the players. In the 2013-2014 seasons, 40% of professional players appeared in 20 matches or more, and 5% of players appeared in 30 matches or more. Matches account for ∼5-11% of exposure to rugby-related activities (matches, team and individual training sessions) during professional competitions. The match injury rate is about 27 times higher than that in training. The working group surmised that players entering a new level of play, players with unresolved previous injuries, players who are relatively older and players who are subjected to rapid increases in load are probably at increased risk of injury. A mix of 'objective' and 'subjective' measures in conjunction with effective communication among team staff and between staff and players was held to be the best approach to monitoring and managing player loads. While comprehensive monitoring holds promise for individually addressing player loads, it brings with it ethical and legal responsibilities that rugby organisations need to address to ensure that players' personal information is adequately protected. Administrators, broadcasters, team owners, team staff and the players themselves have important roles in balancing the desire to have the 'best players' on the field with the ongoing health of players. In contrast, the coaching, fitness and medical staff exert significant control over the activities, duration and intensity of training

  9. Implementation of Motor Imagery during Specific Aerobic Training Session in Young Tennis Players

    Science.gov (United States)

    Guillot, Aymeric; Di Rienzo, Franck; Pialoux, Vincent; Simon, Germain; Skinner, Sarah; Rogowski, Isabelle

    2015-01-01

    The aim of this study was to investigate the effects of implementing motor imagery (MI) during specific tennis high intensity intermittent training (HIIT) sessions on groundstroke performance in young elite tennis players. Stroke accuracy and ball velocity of forehand and backhand drives were evaluated in ten young tennis players, immediately before and after having randomly performed two HIIT sessions. One session included MI exercises during the recovery phases, while the other included verbal encouragements for physical efforts and served as control condition. Results revealed that similar cardiac demand was observed during both sessions, while implementing MI maintained groundstroke accuracy. Embedding MI during HIIT enabled the development of physical fitness and the preservation of stroke performance. These findings bring new insight to tennis and conditioning coaches in order to fulfil the benefits of specific playing HIIT sessions, and therefore to optimise the training time. PMID:26580804

  10. Gender Differentiations of Some Anthropological Characteristics of Karate Players--Cadets.

    Science.gov (United States)

    Jukić, Josefina

    2015-07-01

    The research was conducted with the aim of determining gender differentiations of some anthropological characteristics of male and female cadet karate players. To achieve this aim, a group of 10 morphological variables, ten motor tests, five situation motor test and six technical performance evaluation tests was applied. Two hundred and six competing players were measured, of which 105 male and 101 female. The examinees were divided according to weight categories (lower and higher weight categories). Based on the variance analysis and canon discrimination analysis a conclusion can be made: gender differentiations are most strongly expressed in morphological and basic motor area, and significantly less in the area of specific motor abilities and motor knowledge (technical efficiency).

  11. Implementation of Motor Imagery during Specific Aerobic Training Session in Young Tennis Players.

    Science.gov (United States)

    Guillot, Aymeric; Di Rienzo, Franck; Pialoux, Vincent; Simon, Germain; Skinner, Sarah; Rogowski, Isabelle

    2015-01-01

    The aim of this study was to investigate the effects of implementing motor imagery (MI) during specific tennis high intensity intermittent training (HIIT) sessions on groundstroke performance in young elite tennis players. Stroke accuracy and ball velocity of forehand and backhand drives were evaluated in ten young tennis players, immediately before and after having randomly performed two HIIT sessions. One session included MI exercises during the recovery phases, while the other included verbal encouragements for physical efforts and served as control condition. Results revealed that similar cardiac demand was observed during both sessions, while implementing MI maintained groundstroke accuracy. Embedding MI during HIIT enabled the development of physical fitness and the preservation of stroke performance. These findings bring new insight to tennis and conditioning coaches in order to fulfil the benefits of specific playing HIIT sessions, and therefore to optimise the training time.

  12. Implementation of Motor Imagery during Specific Aerobic Training Session in Young Tennis Players.

    Directory of Open Access Journals (Sweden)

    Aymeric Guillot

    Full Text Available The aim of this study was to investigate the effects of implementing motor imagery (MI during specific tennis high intensity intermittent training (HIIT sessions on groundstroke performance in young elite tennis players. Stroke accuracy and ball velocity of forehand and backhand drives were evaluated in ten young tennis players, immediately before and after having randomly performed two HIIT sessions. One session included MI exercises during the recovery phases, while the other included verbal encouragements for physical efforts and served as control condition. Results revealed that similar cardiac demand was observed during both sessions, while implementing MI maintained groundstroke accuracy. Embedding MI during HIIT enabled the development of physical fitness and the preservation of stroke performance. These findings bring new insight to tennis and conditioning coaches in order to fulfil the benefits of specific playing HIIT sessions, and therefore to optimise the training time.

  13. Memory Kernel in the Expertise of Chess Players

    CERN Document Server

    Schaigorodsky, Ana L; Billoni, Orlando V

    2015-01-01

    In this work we investigate a mechanism for the emergence of long-range time correlations observed in a chronologically ordered database of chess games. We analyze a modified Yule-Simon preferential growth process proposed by Cattuto et al., which includes memory effects by means of a probabilistic kernel. According to the Hurst exponent of different constructed time series from the record of games, artificially generated databases from the model exhibit similar long-range correlations. In addition, the inter-event time frequency distribution is well reproduced by the model for realistic parameter values. In particular, we find the inter-event time distribution properties to be correlated with the expertise of the chess players through the memory kernel extension. Our work provides new information about the strategies implemented by players with different levels of expertise, showing an interesting example of how popularities and long-range correlations build together during a collective learning process.

  14. Game Cinematography: From Camera Control to Player Emotions

    DEFF Research Database (Denmark)

    Burelli, Paolo

    2016-01-01

    Building on the definition of cinematography (Soanes and Stevenson, Oxford dictionary of English. Oxford University Press, Oxford/New York, 2005), game cinematography can be defined as the art of visualizing the content of a computer game. The relationship between game cinematography and its...... traditional counterpart is extremely tight as, in both cases, the aim of cinematography is to control the viewer’s perspective and affect his or her perception of the events represented. However, game events are not necessarily pre-scripted and player interaction has a major role on the quality of a game...... experience; therefore, the role of the camera and the challenges connected to it are different in game cinematography as the virtual camera has to both dynamically react to unexpected events to correctly convey the game story and take into consideration player actions and desires to support her interaction...

  15. Women's football: Player characteristics and demands of the game

    Directory of Open Access Journals (Sweden)

    Vanessa Martínez-Lagunas

    2014-12-01

    Full Text Available The number of scientific investigations on women's football specific to the topics of player characteristics and demands of the game has considerably increased in recent years due to the increased popularity of the women's game worldwide, although they are not yet as numerous as in the case of men's football. To date, only two scientific publications have attempted to review the main findings of studies published in this area. However, one of them was published about 20 years ago, when women's football was still in its infancy and there were only a few studies to report on. The other review was more recent. Nonetheless, its main focus was on the game and training demands of senior elite female players. Thus, information on female footballers of lower competitive levels and younger age groups was not included. Consequently, an updated review is needed in this area. The present article therefore aims to provide an overview of a series of studies that have been published so far on the specific characteristics of female football players and the demands of match-play. Mean values reported in the literature for age (12–27 years, body height (155–174 cm, body mass (48–72 kg, percent body fat (13%–29%, maximal oxygen uptake (45.1–55.5 mL/kg/min, Yo-Yo Intermittent Recovery Test Level 1 (780–1379 m, maximum heart rate (189–202 bpm, 30 m sprint times (4.34–4.96 s, and counter-movement jump or vertical jump (28–50 cm vary mostly according to the players' competitive level and positional role. There are also some special considerations that coaches and other practitioners should be aware of when working with female athletes such as the menstrual cycle, potential pregnancy and lactation, common injury risks (particularly knee and head injuries and health concerns (e.g., female athlete triad, iron deficiency, and anemia that may affect players' football performance, health or return to play. Reported mean values for total distance

  16. Contributions to Using IT in Education: An Educational Video Player

    Directory of Open Access Journals (Sweden)

    Ciprian CUCU

    2010-01-01

    Full Text Available Following the trends of IT use in education we propose four main principles of educational application development: anytime-anywhere access (including access for mobile devices; user-generated content; assigning users an active role inside the platform; creating a correlation between natural activities and educational activities – adding fun into the equation. With these principles in mind we developed a small Educational Player – a movie player that connects to a database to show information relevant to the events in the movie, more specific to the exact key-frame (in the movie time-line at the moment of the request. Though the application is still in a conceptual form, its possibilities make us confident in its future success either as an informal way of learning, or by using it in a formal educational context either as an e-learning tool, either as interactivity tool in a traditional classroom setting.

  17. Procedural Personas for Player Decision Modeling and Procedural Content Generation

    DEFF Research Database (Denmark)

    Holmgård, Christoffer

    2016-01-01

    ." These methods for constructing procedural personas are then integrated with existing procedural content generation systems, acting as critics that shape the output of these systems, optimizing generated content for different personas and by extension, different kinds of players and their decision making styles....... This thesis explores methods for creating low-complexity, easily interpretable, generative AI agents for use in game and simulation design. Based on insights from decision theory and behavioral economics, the thesis investigates how player decision making styles may be defined, operationalised, and measured...... in specific games. It further explores how simple utility functions, easily defined and changed by game designers, can be used to construct agents expressing a variety of decision making styles within a game, using a variety of contemporary AI approaches, naming the resulting agents "Procedural Personas...

  18. A Comparison of Methods for Player Clustering via Behavioral Telemetry

    DEFF Research Database (Denmark)

    Drachen, Anders; Thurau, Christian; Sifa, Rafet;

    2013-01-01

    The analysis of user behavior in digital games has been aided by the introduction of user telemetry in game development, which provides unprecedented access to quantitative data on user behavior from the installed game clients of the entire population of players. Player behavior telemetry datasets...... can be exceptionally complex, with features recorded for a varying population of users over a temporal segment that can reach years in duration. Categorization of behaviors, whether through descriptive methods (e.g. segmentation) or unsupervised/supervised learning techniques, is valuable for finding...... patterns in the behavioral data, and developing profiles that are actionable to game developers. There are numerous methods for unsupervised clustering of user behavior, e.g. k-means/c-means, Nonnegative Matrix Factorization, or Principal Component Analysis. Although all yield behavior categorizations...

  19. Key Distribution based on Three Player Quantum Games

    CERN Document Server

    Toyota, Norihito

    2010-01-01

    We study a new QKD that is different from the scheme proposed by \\cite{Ramz2}, though it essentially takes our ground on three-player quantum games and Greenberg-Horne-Zeilinger triplet entangled state (GHZ state) \\cite{Gree} is used. In our scheme proposed in this article, Bob and Charlie (and Alice also) that they are players in a game get some common key or information (applied strategies and their payoffs in the game) by knowing some results of the measurement made by Alice. There is not any arbiter in our scheme, since existence of an arbiter increase the risk of wiretapping. For it is difficult to detect wiretapping, when an arbiter repeatedly sends classical information. Lastly we discuss robustness for eavesdrop. We show that though maximally entangled case and non-entangled case provided essentially equivalent way in QKD, the latter is not available in the case there are some eavesdroppers.

  20. Real-Time Game Adaptation for Optimizing Player Satisfaction

    DEFF Research Database (Denmark)

    Yannakakis, Georgios; Hallam, John

    2009-01-01

    preferences for augmented-reality game players. An adaptive mechanism then adjusts controllable game parameters in real time in order to improve the entertainment value of the game for the player. The basic approach presented here applies gradient ascent to the user model to suggest the direction of parameter...... adjustment that leads toward games of higher entertainment value. A simple rule set exploits the derivative information to adjust specific game parameters to augment the entertainment value. Those adjustments take place frequently during the game with interadjustment intervals that maintain the user model......'s accuracy. Performance of the adaptation mechanism is evaluated using a game survey experiment. Results indicate the efficacy and robustness of the mechanism in adapting the game according to a user's individual playing features and enhancing the gameplay experience. The limitations and the use...

  1. The Distribution of Benefits for Players in Agricultural Industrial Chain

    Institute of Scientific and Technical Information of China (English)

    Wanming; LI; Huibo; SUN

    2015-01-01

    Players of the agricultural industrial chain pursue their own profit maximization,which can lead to conflicts of interest and affect the stability of the industrial chain. Therefore,fair and reasonable profit allocation mechanism is the key to guaranteeing the development and strengthening the strategic alliance relationship between participate members. Shapley model is an effective method to solve the profit distribution in cooperative relations. But it does not consider the three factors: risks faced by players during the operation of the agricultural industrial chain,technology innovation ability,and the degree of participating in the cooperation. So,correction factors are introduced to modify the Shapley value model,in order to make the distribution of benefits more equitable and reasonable,and effectively guide practice.

  2. From Bovine Horde to Urban Players

    DEFF Research Database (Denmark)

    Galloway, Anne; Ludvigsen, Martin; Sundholm, Hillevi

    2003-01-01

    This paper tells a story of an international and multidisciplinary atelier-based design experiment. For ten days in Rome, the ‘White Group’ explored a cyclical process of fieldwork and intervention, critical reflection, design concept generation, and prototyping to generate two novel and situated...

  3. Perceived exercise benefits and barriers among power wheelchair soccer players

    OpenAIRE

    J. P. Barfield, DA; Laurie A. Malone, PhD

    2013-01-01

    Lack of exercise is a major risk factor for secondary conditions among persons dependent upon motorized wheelchairs. Power wheelchair soccer is a unique exercise opportunity for this population, and understanding factors that influence exercise decision-making is necessary for clinicians to help those in motorized chairs reduce their secondary risk. Therefore, this study examined differences in perceived benefits and barriers to exercise among power wheelchair soccer players using a mixed-met...

  4. Psychological Gender and Emotional Intelligence in Youth Female Soccer Players

    Directory of Open Access Journals (Sweden)

    Rutkowska Katarzyna

    2015-09-01

    Full Text Available Many sports (for instance soccer are stereotypically perceived as a male activity. Even so, more and more women decide to become competitive athletes. Since the theory of sport requires comprehensive explanations and the practice of sport needs clear guidelines, interdisciplinary studies into the nature of sport, including its psychological aspects, are necessary. Analysing the psychological profile of female soccer players, particularly those who are about to become professional athletes, can provide many interesting insights into the specific character of female youth sport and show where improvements can be made in athletic training programmes (especially in mental training. It is therefore important to study psychological gender that determines social behaviours and to analyse female athletes’ emotional intelligence. Emotional intelligence is defined as a set of emotional competencies that determine the effectiveness of human behaviours. Psychological gender and emotional intelligence have a significant effect on human adaptability and the efficiency of psychosocial functioning. This research was undertaken with the dual purpose of identifying the psychological gender and emotional intelligence of female soccer players. It involved 54 secondary-school girls, some of whom attended a sports class and others played on the Polish national team. The following tools were used to carry out the research: the Gender Assessment Inventory (IPP [This and the other acronyms derive from the Polish language]-developed by Kuczyńska and the Emotional Intelligence Questionnaire (INTE; created by Jaworowska and Matczak. As shown by the analysis of the results, most female soccer players in the study were androgynous and the level of their emotional intelligence was significantly higher than in other participants. This also seems to point to their significantly greater adaptability. At the same time, the level of emotional intelligence in many players was

  5. Movement Demands of Elite U20 International Rugby Union Players.

    Science.gov (United States)

    Cunningham, Daniel; Shearer, David A; Drawer, Scott; Eager, Robin; Taylor, Neil; Cook, Christian; Kilduff, Liam P

    2016-01-01

    The purpose of this study was to quantify movement demands of elite international age grade (U20) rugby union players during competitive tournament match play. Forty elite professional players from an U20 international performance squad were monitored using 10 Hz global positioning systems (GPS) during 15 international tournament matches during the 2014/15 and 2015/16 seasons. Data on distances, velocities, accelerations, decelerations, high metabolic load (HML) distance and efforts, and number of sprints were derived. Data files from players who played over 60 min (n = 161) were separated firstly into Forwards and Backs, and more specifically into six positional groups; FR--Front Row (prop & hooker), SR--Second Row, BR--Back Row (Flankers & No.8), HB--Half Backs (scrum half & outside half), MF--Midfield (centres), B3--Back Three (wings & full back) for match analysis. Analysis revealed significant differences between forwards and backs positions. Backs scored higher on all variables measured with the exception of number of moderate accelerations, decelerations (no difference). The centres covered the greatest total distance with the front row covering the least (6.51 ± 0.71 vs 4.97 ± 0.75 km, p < 0.001). The front row also covered the least high speed running (HSR) distance compared to the back three (211.6 ± 112.7 vs 728.4 ± 150.2 m, p < 0.001) who covered the most HSR distance, affirming that backs cover greater distances but forwards have greater contact loads. These findings highlight for the first time differences in the movement characteristics of elite age grade rugby union players specific to positional roles.

  6. Multiple Past Concussions in High School Football Players

    Science.gov (United States)

    Brooks, Brian L.; Mannix, Rebekah; Maxwell, Bruce; Zafonte, Ross; Berkner, Paul D.; Iverson, Grant L.

    2017-01-01

    Background There is increasing concern about the possible long-term effects of multiple concussions, particularly on the developing adolescent brain. Whether the effect of multiple concussions is detectable in high school football players has not been well studied, although the public health implications are great in this population. Purpose To determine if there are measureable differences in cognitive functioning or symptom reporting in high school football players with a history of multiple concussions. Study Design Cross-sectional study; Level of evidence, 3. Methods Participants included 5232 male adolescent football players (mean [±SD] age, 15.5 ± 1.2 years) who completed baseline testing between 2009 and 2014. On the basis of injury history, athletes were grouped into 0 (n = 4183), 1 (n = 733), 2 (n = 216), 3 (n = 67), or ≥4 (n = 33) prior concussions. Cognitive functioning was measured by the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery, and symptom ratings were obtained from the Post-Concussion Symptom Scale. Results There were no statistically significant differences between groups (based on the number of reported concussions) regarding cognitive functioning. Athletes with ≥3 prior concussions reported more symptoms than did athletes with 0 or 1 prior injury. In multivariate analyses, concussion history was independently related to symptom reporting but less so than developmental problems (eg, attention or learning problems) or other health problems (eg, past treatment for psychiatric problems, headaches, or migraines). Conclusion In the largest study to date, high school football players with multiple past concussions performed the same on cognitive testing as those with no prior concussions. Concussion history was one of several factors that were independently related to symptom reporting. PMID:27474382

  7. Cavum Septi Pellucidi in Symptomatic Former Professional Football Players.

    Science.gov (United States)

    Koerte, Inga K; Hufschmidt, Jakob; Muehlmann, Marc; Tripodis, Yorghos; Stamm, Julie M; Pasternak, Ofer; Giwerc, Michelle Y; Coleman, Michael J; Baugh, Christine M; Fritts, Nathan G; Heinen, Florian; Lin, Alexander; Stern, Robert A; Shenton, Martha E

    2016-02-15

    Post-mortem studies reveal a high rate of cavum septi pellucidi (CSP) in chronic traumatic encephalopathy (CTE). It remains, however, to be determined whether or not the presence of CSP may be a potential in vivo imaging marker in populations at high risk to develop CTE. The aim of this study was to evaluate CSP in former professional American football players presenting with cognitive and behavioral symptoms compared with noncontact sports athletes. Seventy-two symptomatic former professional football players (mean age 54.53 years, standard deviation [SD] 7.97) as well as 14 former professional noncontact sports athletes (mean age 57.14 years, SD 7.35) underwent high-resolution structural 3T magnetic resonance imaging. Two raters independently evaluated the CSP, and interrater reliability was calculated. Within National Football League players, an association of CSP measures with cognitive and behavioral functioning was evaluated using a multivariate mixed effects model. The measurements of the two raters were highly correlated (CSP length: rho = 0.98; Intraclass Correlation Coefficient [ICC] 0.99; p football players compared with athlete controls. In addition, a greater length of CSP was associated with decreased performance on a list learning task (Neuropsychological Assessment Battery List A Immediate Recall, p = 0.04) and decreased test scores on a measure of estimate verbal intelligence (Wide Range Achievement Test Fourth Edition Reading Test, p = 0.02). Given the high prevalence of CSP in neuropathologically confirmed CTE in addition to the results of this study, CSP may serve as a potential early in vivo imaging marker to identify those at high risk for CTE. Future research is needed to investigate the pathomechanism underlying the development of CSP after repetitive head impacts, and its potential association with neuropathologically confirmed CTE.

  8. Data-Based Interval Throwing Programs for Baseball Players

    OpenAIRE

    Axe, Michael; Hurd, Wendy; Snyder-Mackler, Lynn

    2009-01-01

    Context: Baseball throwing injuries are common. Emphasis on injury prevention and rehabilitation is made in an attempt to keep athletes on the field of competition. Interval throwing programs are an integral part of training, conditioning, and returning an injured baseball player to the game. Evidence Acquisition: Development of data-driven programs was based on the number, type, distance, and intensity of throws during games, across the spectrum of ages and positions for baseball athletes at...

  9. Plantar Fascia Rupture in a Professional Soccer Player

    OpenAIRE

    Suzue, Naoto; Iwame, Toshiyuki; Kato, Kenji; Takao, Shoichiro; Tateishi, Tomohiko; Takeda, Yoshitsugu; Hamada, Daisuke; Goto, Tomohiro; Takata, Yoichiro; Matsuura, Tetsuya; Sairyo, Koichi

    2014-01-01

    We report the case of a 29-year-old male professional soccer player who presented with symptoms of plantar fasciitis. His symptoms occurred with no remarkable triggers and gradually worsened despite conservative treatments including taping, use of insoles, and physical therapy. Local corticosteroid injection was given twice as a further intervention, but his plantar fascia partially ruptured 49 days after the second injection. He was treated conservatively with platelet-rich plasma, and magne...

  10. Do stingers affect scapular kinematics in rugby players?

    Science.gov (United States)

    Kawasaki, Takayuki; Maki, Nobukazu; Shimizu, Kyoko; Ota, Chihiro; Urayama, Shingo; Moriya, Shuichi; Kaketa, Takefumi; Kobayashi, Hideo; Kaneko, Kazuo

    2014-12-01

    Scapular dyskinesis is observed in subjects with pathologic conditions of the shoulder; however, there is limited information about the factors related to scapular dyskinesis among participants in rugby. The purpose of this study was to investigate the incidence, reliability, and relationships between scapular dyskinesis and variables related to the shoulder in high-school rugby players. A total of 164 Japanese high-school rugby players were evaluated with questionnaires, physical examinations, and a video analysis during their preseason. After evaluation of the inter-rater reliability of a classification of scapular dyskinesis, the outcomes were analyzed to assess the relationships between scapular dyskinesis and other variables during the preseason. The data were assessed with a logistic regression analysis calculating the odds ratios (OR). The inter-rater reliability among 3 blinded observers based on the Fleiss κ value and percentage agreement was .52 and 79.0%, respectively, which indicates that the method is moderately reliable. Scapular dyskinesis was identified in 16 (10.1%) shoulders among 159 players, with type I being prominent. A multivariate logistic regression analysis revealed that a type I dyskinesis was significantly associated with a past history of stingers with projected pain to the affected side of the shoulder (OR, 3.7) and the player's competitive grade at the time of the survey (OR, 3.9). Scapular dyskinesis is significantly associated with a past history of stingers. This suggests that stingers are a causative factor of scapular dyskinesis in the rugby population. Our method of evaluating scapular dyskinesis in collision athletes exhibits moderate reliability. Copyright © 2014 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  11. Mechanisms of traumatic shoulder injury in elite rugby players

    Science.gov (United States)

    Crichton, James; Jones, Doug R; Funk, Lennard

    2012-01-01

    Background Shoulder injuries in rugby players are common, but the mechanisms of injury are less well understood. This study aims to elucidate common mechanisms of injury and identify the patterns of injury they produce. Materials and methods Twenty-four elite rugby players, referred to the senior author for diagnosis and management of shoulder injuries, were selected. Videos of the injuries were independently reviewed by rugby-medical experts to describe the mechanisms of injury. The mechanisms reported were collated and analysed to determine the level of agreement between reviewers and conclude an overall description of injury mechanisms. Results The authors identified three mechanisms of shoulder injury from the video analysis. These are the ‘Try-Scorer’, characterised by hyperflexion of the outstretched arm such as when scoring a try; the ‘Tackler’, extension of the abducted arm behind the player while tackling; and the ‘Direct Impact’, a direct blow to the arm or shoulder when held by the side in neutral or slight adduction. The Try Scorer and Tackler mechanisms both involve a levering force on the glenohumeral joint (GHJ). These mechanisms predominantly cause GHJ dislocation, with Bankart, reverse Bankart and superior labrum anterior–posterior tears. The Try-Scorer Mechanism also caused the majority (83%) of rotator cuff tears. The Direct Hit mechanism resulted in GHJ dislocation and labral injury in 37.5% of players and was most likely to cause acromioclavicular joint dislocation and scapula fractures, injuries that were not seen with the other mechanisms. Conclusion Greater understanding of the mechanisms involved in rugby shoulder injury is useful in understanding the pathological injuries, guiding treatment and rehabilitation and aiding the development of injury-prevention methods. PMID:22510645

  12. Linear Quadratic Controller with Fault Detection in Compact Disk Players

    DEFF Research Database (Denmark)

    Vidal, Enrique Sanchez; Hansen, K.G.; Andersen, R.S.

    2001-01-01

    The design of the positioning controllers in Optical Disk Drives are today subjected to a trade off between an acceptable suppression of external disturbances and an acceptable immunity against surfaces defects. In this paper an algorithm is suggested to detect defects of the disk surface combined...... with an observer and a Linear Quadratic Regulator. As a result, the mentioned trade off is minimized and the playability of the tested compact disk player is considerably enhanced....

  13. Improved control of exogenous attention in action video game players

    Directory of Open Access Journals (Sweden)

    Matthew S Cain

    2014-02-01

    Full Text Available Action video game players have demonstrated a number of attentional advantages over non-players. Here, we propose that many of those benefits might be underpinned by improved control over exogenous (i.e., stimulus-driven attention. To test this we used an anti-cuing task, in which a sudden-onset cue indicated that the target would likely appear in a separate location on the opposite side of the fixation point. When the time between the cue onset and the target onset was short (40 ms, non-players (nVGPs showed a typical exogenous attention effect. Their response times were faster to targets presented at the cued (but less probable location compared with the opposite (more probable location. Video game players (VGPs, however, were less likely to have their attention drawn to the location of the cue. When the onset asynchrony was long (600 ms, VGPs and nVGPs were equally able to endogenously shift their attention to the likely (opposite target location. In order to rule out processing-speed differences as an explanation for this result, we also tested VGPs and nVGPs on an attentional blink task. In a version of the attentional blink task that minimized demands on task switching and iconic memory, VGPs and nVGPs did not differ in second target identification performance (i.e., VGPs had the same magnitude of attentional blink as nVGPs, suggesting that the anti-cuing results were due to flexible control over exogenous attention rather than to more general speed-of-processing differences.

  14. Hip adduction and abduction strength profiles in elite soccer players

    DEFF Research Database (Denmark)

    Serner, Andreas; Petersen, Jesper; Madsen, Thomas Moller

    2011-01-01

    An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side-......-to-side symmetry in isometric hip adduction and abduction strength can be assumed in soccer players remains uncertain....

  15. A survey of orofacial injuries among basketball players.

    Science.gov (United States)

    Azodo, Clement Chinedu; Odai, Chukwuemeka Danielson; Osazuwa-Peters, Nosayaba; Obuekwe, Ozoemene Ndubuisi

    2011-02-01

    To determine the prevalence of orofacial injuries among basketball players in Benin City, Nigeria and to survey the athletes' awareness, attitude and use of mouthguards. A cross-sectional survey of basketball players in the standard basketball arena in Benin City was conducted between November 2009 and January 2010. A self-administered questionnaire elicited information on demography, the prevalence of oral and facial injuries, distribution of site and cause of orofacial injuries, athletes' knowledge, attitudes and usage of mouthguards. Data were subjected to descriptive statistics and Chi square test. The response rate was 78%. Of the 156 respondents, 79.5% were male and 20.5% female, with a mean age of 23.1 years. The distributions was amateurs (61.5%) professionals (38.5%). The mean number of injuries in previous 12 months was 3.7 ± 1.8. The prevalence of both facial and oral injuries among the respondents was 62.8% with the lip and gingiva most commonly involved respectively. The common causes of the orofacial injury reported were from elbows of opponents, falling and collisions with other players. The prevalence of injury was not significantly associated with demography, category, competition and duration of participation. More than half had heard and seen mouthguards and the coach was the leading source of information. The reasons for non-use of mouthguard were mostly ignorance, non-availability and non-affordability. The high prevalence of orofacial injury among basketball players reported in this study justifies the need for multidisciplinary injury prevention interventional approach with emphasis on the rules of the games. © 2011 FDI World Dental Federation.

  16. Discussion for pain of shoulder muscles in badminton player

    OpenAIRE

    兒嶋, 昇; Kojima, Noboru; 升, 佑二郎; Masu, Yujiro; 野瀬, 朋洋; Nose, Tomohiro

    2013-01-01

    This study aimed to provide a basis for the development of appropriate preventive measures during training and coaching by examining shoulder impingement in Japanese top-level university badminton players. As the contracture of muscles, such as the anterior and middle scalene muscles, as well as the infraspinatus, was likely to cause pain, it may be effective to perform conditioning to reduce such muscle contracture during coaching in order to reduce the occurrence of impairment, and impro...

  17. Psychological Gender and Emotional Intelligence in Youth Female Soccer Players.

    Science.gov (United States)

    Rutkowska, Katarzyna; Bergier, Józef

    2015-09-29

    Many sports (for instance soccer) are stereotypically perceived as a male activity. Even so, more and more women decide to become competitive athletes. Since the theory of sport requires comprehensive explanations and the practice of sport needs clear guidelines, interdisciplinary studies into the nature of sport, including its psychological aspects, are necessary. Analysing the psychological profile of female soccer players, particularly those who are about to become professional athletes, can provide many interesting insights into the specific character of female youth sport and show where improvements can be made in athletic training programmes (especially in mental training). It is therefore important to study psychological gender that determines social behaviours and to analyse female athletes' emotional intelligence. Emotional intelligence is defined as a set of emotional competencies that determine the effectiveness of human behaviours. Psychological gender and emotional intelligence have a significant effect on human adaptability and the efficiency of psychosocial functioning. This research was undertaken with the dual purpose of identifying the psychological gender and emotional intelligence of female soccer players. It involved 54 secondary-school girls, some of whom attended a sports class and others played on the Polish national team. The following tools were used to carry out the research: the Gender Assessment Inventory (IPP [This and the other acronyms derive from the Polish language]-developed by Kuczyńska) and the Emotional Intelligence Questionnaire (INTE; created by Jaworowska and Matczak). As shown by the analysis of the results, most female soccer players in the study were androgynous and the level of their emotional intelligence was significantly higher than in other participants. This also seems to point to their significantly greater adaptability. At the same time, the level of emotional intelligence in many players was average or low

  18. The Value Relevance of Players in the Football Industry

    OpenAIRE

    Davies, Jonathan

    2010-01-01

    This paper investigates the value relevance of players to football clubs. Relevance both in relation to on-field success as well as external valuation are assessed. Both a single and multiple regression analysis are utilised, with the media and software industries used for comparison. Although there has been lots of research into the value relevance of intangible assets as their relevance to the modern economy grows, there has been relatively little investigation into specific industries, par...

  19. Ιnjuries in greek amateur soccer players

    OpenAIRE

    GEORGIOS TSIGANOS

    2007-01-01

    The purpose of this study was to record retrospectivelythe epidemiology of injuries in amateur Greek soccer players. Three hundred and one (301) amateur soccer playersvoluntarily participated in the study. Participants answered aspecially-designed questionnaire that included questionsabout demographics, playing surface, division, position,hours of training plus participation, the use of stretching orprophylactic tape, the injury mechanism, the location andtype of injury. During the five years...

  20. Hip adduction and abduction strength profiles in elite soccer players

    DEFF Research Database (Denmark)

    Thorborg, Kristian; Serner, Andreas; Petersen, Jesper

    2011-01-01

    An ipsilateral hip adduction/abduction strength ratio of more than 90%, and hip adduction strength equal to that of the contralateral side have been suggested to clinically represent adequate strength recovery of hip adduction strength in athletes after groin injury. However, to what extent side-......-to-side symmetry in isometric hip adduction and abduction strength can be assumed in soccer players remains uncertain....

  1. Gambling and football: Epidemiological research on gambling participation and problem gambling among adult football players in Iceland

    OpenAIRE

    2016-01-01

    There is not much known about the gambling behaviour of Icelandic football players. Aims of the current study were to examine the prevalence of total gambling participation and problem gambling among Icelandic football players, to examine if Icelandic football players have been involved in behaviour that could possibly be related to game fixing and to examine players attitudes towards banning coaches and players to gamble on games the Icelandic championship. Participants were 725, of which 75...

  2. How should "hot" players in basketball be defended? The use of fast-and-frugal heuristics by basketball coaches and players in response to streakiness.

    Science.gov (United States)

    Csapo, Peter; Avugos, Simcha; Raab, Markus; Bar-Eli, Michael

    2015-01-01

    Previous research has shown that changes in shot difficulty may have rendered the hot-hand effect in basketball unobservable and are potentially a result of defensive adjustments. However, it has not been directly analysed whether strategic changes indeed take place in response to streakiness and whether they are effective with respect to winning games. The current work consists of an experimental study with 18 professional coaches and 20 players based on video sequences from National Basketball Association games, where the shown player displayed a streaky performance in half of the sequences. While coaches were asked to devise a defensive strategy after each viewed sequence, players had to assume the role of the shown player and decide whether to shoot or pass the ball. We find that coaches tended to increase the defensive pressure significantly more often on presumably hot players and thus make use of the hot-hand heuristic. Meanwhile, players chose to shoot more frequently in low-pressure and streaky situations but selected "pass" regardless of the previous performance when they faced increased defensive pressure. Assuming that a streaky player's performance is indeed elevated during hot phases, hot-hand behaviour can be considered adaptive in certain situations as it led hot players to pass instead of shoot.

  3. NFL Physicians: Committed to Excellence in Patient-Player Care.

    Science.gov (United States)

    2016-11-01

    The National Football League Physicians Society read with disappointment the article "A Proposal to Address NFL Club Doctors' Conflicts of Interest and to Promote Player Trust." In spite of the authors' suggestions, NFL physicians are accomplished medical professionals who abide by the highest ethical standards in providing treatment to all of their patients, including those who play in the NFL. It defies logic for the authors not to have engaged experienced and active NFL physicians from the very start of their effort to explore, challenge, and recommend significant alterations to the delivery of health care to NFL players. As troubling as this article is from so many perspectives, it does represent an opportunity for the NFLPS to set the record straight and call attention to the excellent quality of care NFL players receive. In addition, it represents an opportunity to expose the extraordinarily weak evidence presented in the article and to refute the baseless allegations that challenge the high ethical standards of NFL physicians. Contrary to solid scientific research that starts with a hypothesis based on theory, in this case, it seems quite apparent that the authors started with a predetermined conclusion and set out to justify it. Their premise was flawed, and they failed in their execution. © 2016 The Hastings Center.

  4. Multiobjective Interaction Programming Problem with Interaction Constraint for Two Players

    Directory of Open Access Journals (Sweden)

    Min Jiang

    2012-01-01

    Full Text Available This paper extends an existing cooperative multi-objective interaction programming problem with interaction constraint for two players (or two agents. First, we define an s-optimal joint solution with weight vector to multi-objective interaction programming problem with interaction constraint for two players and get some properties of it. It is proved that the s-optimal joint solution with weight vector to the multi-objective interaction programming problem can be obtained by solving a corresponding mathematical programming problem. Then, we define another s-optimal joint solution with weight value to multi-objective interaction programming problem with interaction constraint for two players and get some of its properties. It is proved that the s-optimal joint solution with weight vector to multi-objective interaction programming problem can be obtained by solving a corresponding mathematical programming problem. Finally, we build a pricing multi-objective interaction programming model for a bi-level supply chain. Numerical results show that the interaction programming pricing model is better than Stackelberg pricing model and the joint pricing model.

  5. Atlantoaxial instability after a header in an amateur soccer player.

    Science.gov (United States)

    Werle, Stephan; Nahleh, Kais Abu; Boehm, Heinrich

    2015-03-01

    Case report and literature review. To report a unique case of atlantoaxial instability after a header in a 37-year-old amateur soccer player and to discuss the injury pattern in relation to the impact of heading. Although there is potential for cervical spine injuries, the rates in soccer are low compared with other contact or even noncontact sports. No cases of acute post-traumatic atlantoaxial instability after heading have ever been reported in a MEDLINE-listed article. A 37-year-old male soccer player experienced acute upper neck pain and transient quadriplegia after heading a long-distance ball on 2 occasions during a match. Imaging revealed atlantoaxial instability. Persistent neurological symptoms on conservative treatment led to his referral to our department. The considerable instability required surgical intervention. Transarticular C1-C2 fixation and posterior fusion with structural iliac crest grafting were performed. The procedure immediately led to complete relief of the neurological symptoms. After an uneventful postoperative recovery, follow-up at 9 months revealed solid fusion. The patient remained symptom free. Heading the ball in soccer can potentially lead to atlantoaxial instability. Ligamentous damage can theoretically be caused by anteriorly directed and rotational overload. However, the causative mechanism remains unclear. Diagnostic workup should consider dynamic imaging in players with transient neurological symptoms after minor trauma to the cervical spine. N/A.

  6. Examining Neurocognitive Function in Previously Concussed Interscholastic Female Soccer Players.

    Science.gov (United States)

    Forbes, Cameron R; Glutting, Joseph J; Kaminski, Thomas W

    2016-01-01

    Awareness of sport-related concussions in soccer has gained recent attention in the medical community. Interestingly, purposeful heading-a unique yet strategic and inherent part of soccer-involves repeated subconcussive blows to the head. We divided 210 female interscholastic soccer players into control (CON [never concussed]) and experimental (EXP [previously concussed]) groups. We assessed neurocognitive performance using the Automated Neuropsychological Assessment Metrics computer program before and after the players' competitive season. Headers were recorded at all sanctioned matches. Data were analyzed using a series of one-way analyses of covariance and t tests. Both groups essentially played in the same number of games (EXP = 16.1 vs. CON = 16.1) and had an equal number of total headers (EXP = 24.9 vs. CON = 24.3). Additionally, headers per game were surprisingly low in both groups (1.4 in EXP vs. 1.3 in CON). Unexpectedly, there were no significant differences between the EXP and CON groups across all dependent variables measured (p > .05). This study suggests that although previously concussed players involve themselves in purposeful heading (i.e., subconcussive insults) throughout a competitive season, there appear to be no negative consequences on neuropsychological test performance or concussion-related symptoms. Additional research is needed to determine what may result during the course of a playing career.

  7. Muscle power and repeated sprint ability in soccer players

    Directory of Open Access Journals (Sweden)

    Saray Giovana dos Santos

    2010-06-01

    Full Text Available Muscle power is one of the most important physical qualities of soccer playerperformance and needs to be maintained during a match. Thus, the aim of this study was toinvestigate the levels of muscle power in soccer players before and after performing repeatedsprints (RS, and the association between power and RS performance. Twenty soccer playersfrom the under-20 category aged 18-20 years participated in this study. The study consisted ofthe execution of vertical jumps, execution of RS, new execution of vertical jumps, and collectionof blood samples. The continuous jump (CJ test was performed on a piezoelectric force platformfor the measurement of muscle power and the RAST test was used to evaluate RS ability. Nosignificant difference in the levels of muscle power was observed after RS (p=0.57. Significantdifferences were observed in the first to fifth sprint times (p<0.01, but not between the fifth andsixth sprint (p=0.06. CJ height before RS was correlated with first sprint time (r=-0.62, p<0.01,best sprint time (r=-0.60, p<0.01, and average sprint time (r= -0.54, p<0.01. In conclusion,the soccer players studied showed no significant reduction in muscle power after RS. A decreasein performance was observed from the first to the fifth sprint, but not between the fifth and sixthsprint. The muscle power of soccer players was a determinant factor to perform one maximumsprint, as well as successive sprints.

  8. Dribbling determinants in sub-elite youth soccer players.

    Science.gov (United States)

    Zago, Matteo; Piovan, Andrea Gianluca; Annoni, Isabella; Ciprandi, Daniela; Iaia, F Marcello; Sforza, Chiarella

    2016-01-01

    Dribbling speed in soccer is considered critical to the outcome of the game and can assist in the talent identification process. However, little is known about the biomechanics of this skill. By means of a motion capture system, we aimed to quantitatively investigate the determinants of effective dribbling skill in a group of 10 Under-13 sub-elite players, divided by the median-split technique according to their dribbling test time (faster and slower groups). Foot-ball contacts cadence, centre of mass (CoM), ranges of motion (RoM), velocity and acceleration, as well as stride length, cadence and variability were computed. Hip and knee joint RoMs were also considered. Faster players, as compared to slower players, showed a 30% higher foot-ball cadence (3.0 ± 0.1 vs. 2.3 ± 0.2 contacts · s(-1), P run with the ball through a shorter path in a more economical way. To effectively develop dribbling skill, coaches are encouraged to design specific practices where high stride frequency and narrow run trajectories are required.

  9. Overload and neovascularization of shoulder tendons in volleyball players

    Directory of Open Access Journals (Sweden)

    Notarnicola Angela

    2012-08-01

    Full Text Available Abstract Background In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. Results No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7% than middle hitters (53.7% (p = 0.01, opposite hitters (55.5% (p = 0.02 and libero players (54.4% (p = 0.008, whereas there were no differences in setters (56.2% (p > 0.05. Conclusions The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles.

  10. How to be a better team player: fifty strategies.

    Science.gov (United States)

    Hills, Laura

    2012-01-01

    Many medical practice employees have become skeptical of the phrase be a team player and with good reason. Too often the phrase means simply to keep your mouth shut and to go along with what everyone else wants. However, being a team player has real meaning and value, and it doesn't mean that you must knuckle under to pressure. This article suggests 50 strategies that will help you become a better team player in your medical practice. It explores ways for you to manage your emotions and to translate them into effective and strategic communication. It teaches you how to read the emotions of your teammates and to listen actively to what they say. Most of all, this article will help you develop a team attitude and live that attitude every day in your medical practice through your behaviors. This article is laced with more than a half-dozen action tips. It includes a description of the most pervasive, destructive, and selfish team roles that you will want to avoid. It offers a clear description of the difference between a group and a team. Finally, this article includes five fun and effective team-building exercises for you to use in your medical practice to boost morale, improve your effectiveness, and strengthen your medical practice team.

  11. Y-balance normative data for female collegiate volleyball players.

    Science.gov (United States)

    Hudson, Christy; Garrison, J Craig; Pollard, Kalyssa

    2016-11-01

    The Lower Quarter Y Balance (YBT-LQ) Test performance varies depending on competitive level, sport, gender, and age; therefore, determining normative scores specific to a population may be helpful in identifying injury-risk thresholds and return-to-play criteria following an injury. The purpose of this study was to determine normative YBT-LQ scores by assessing a subset of female, Division I volleyball players. A descriptive analysis cohort study. Ninety healthy (19.6 ± 1.2 y/o), collegiate female volleyball players. YBT-LQ was measured in 3 distinct directions of anterior (ANT), posteromedial (PM) and posterolateral (PL) on both the dominant and non-dominant limbs. In addition, a one way ANOVA was performed to determine mean group differences of YBT-LQ dominant and non-dominant limb composite score across position. Baseline values for this population were 94.1 ± 6.6% on the dominant limb and 93.9 ± 6.2% on the non-dominant limb. There were no significant differences for YBT-LQ composite scores on dominant (P = 0.867) and non-dominant (P = 0.989) limbs between position. This study identified normative YBT-LQ composite scores for healthy, female, collegiate volleyball players. Participants performed similarly despite their position. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Overload and neovascularization of shoulder tendons in volleyball players

    Science.gov (United States)

    2012-01-01

    Background In overhead sports like volleyball, the onset of a rotator cuff tendinopathy due to functional overload is a common observation. An angiofibroblastic etiopathogenesis has been hypothesized, whereby a greater anaerobic metabolism occurs in critical zones of the tendon with a lower degree of vascularization; this would induce collagen and extracellular matrix degradation, that could then trigger a compensatory neovascularization response. We performed a clinical observational study of 80 elite volleyball players, monitoring the perfusion values of the supraspinatus tendons by oximetry. Results No statistically significant differences were found between the oximetry data and age, sex or years of sports activity, nor when comparing the right and left arm or the dominant and non-dominant arm. A statistically significant difference was found for the dominant arm values in relation to the competitive role, higher values being obtained in outside hitters (62.7%) than middle hitters (53.7%) (p = 0.01), opposite hitters (55.5%) (p = 0.02) and libero players (54.4%) (p = 0.008), whereas there were no differences in setters (56.2%) (p > 0.05). Conclusions The different tendon vascularization values found in players with different roles in the team may be attributed to a response to the specific biomechanical demands posed by the different overhead throwing roles. PMID:22853746

  13. Strength, speed and power characteristics of elite rugby league players.

    Science.gov (United States)

    de Lacey, James; Brughelli, Matt E; McGuigan, Michael R; Hansen, Keir T

    2014-08-01

    The purpose of this article was to compare strength, speed, and power characteristics between playing position (forwards and backs) in elite rugby league players. A total of 39 first team players (height, 183.8 ± 5.95 cm; body mass, 100.3 ± 10.7 kg; age, 24 ± 3 years) from a National Rugby League club participated in this study. Testing included 10-, 40-m sprint times, sprint mechanics on an instrumented nonmotorized treadmill, and concentric isokinetic hip and knee extension and flexion. Backs, observed to have significantly (p ≤ 0.05) lighter body mass (effect size [ES] = 0.98), were significantly faster (10-m ES = 1.26; 40-m ES = 1.61) and produced significantly greater relative horizontal force and power (ES = 0.87 and 1.04) compared with forwards. However, no significant differences were found between forwards and backs during relative isokinetic knee extension, knee flexion, relative isokinetic hip extension, flexion, prowler sprints, sprint velocity, contact time, or flight time. The findings demonstrate that backs have similar relative strength in comparison with forwards, but run faster overground and produce significantly greater relative horizontal force and power when sprinting on a nonmotorized instrumented treadmill. Developing force and power in the horizontal direction may be beneficial for improving sprint performance in professional rugby league players.

  14. Growth and maturity status of elite British junior tennis players.

    Science.gov (United States)

    Myburgh, Gillian K; Cumming, Sean P; Coelho E Silva, Manuel; Cooke, Karl; Malina, Robert M

    2016-10-01

    Growth and maturation impact the selection, development and progression of youth athletes. Individual differences in the growth and maturity may afford a performance advantage, clouding coaches and practitioners' perceptions regarding current ability and future potential. This may result in the exclusion of talented, yet less physically gifted athletes. Participants were 91 male (n = 47) and female (n = 44) elite British Junior tennis players, 8-17 years of age (12.5 ± 1.9 years). Height and body mass were measured and compared to growth charts; hand-wrist radiographs were taken. Skeletal age (SA) was estimated with the Fels method and contrasted to chronological age (CA). Mean height and body mass of individual players ranged between the 50th and 90th centiles for age and sex. Females were advanced in SA relative to CA (0.3-0.89 years.) from 8 years. Males were average to delayed in maturation from 8 to 12 years, but advanced in SA from 14 to 16 years (0.75-1.23 years). Individual differences in growth and maturation appear to contribute towards the selection of elite junior tennis players, with a bias towards males and females who are advanced in maturation and comparatively tall and heavy for their age. This has important implications for talent identification and development.

  15. Predicting Player Position for Talent Identification in Association Football

    Science.gov (United States)

    Razali, Nazim; Mustapha, Aida; Yatim, Faiz Ahmad; Aziz, Ruhaya Ab

    2017-08-01

    This paper is set to introduce a new framework from the perspective of Computer Science for identifying talents in the sport of football based on the players’ individual qualities; physical, mental, and technical. The combination of qualities as assessed by coaches are then used to predict the players’ position in a match that suits the player the best in a particular team formation. Evaluation of the proposed framework is two-fold; quantitatively via classification experiments to predict player position, and qualitatively via a Talent Identification Site developed to achieve the same goal. Results from the classification experiments using Bayesian Networks, Decision Trees, and K-Nearest Neighbor have shown an average of 98% accuracy, which will promote consistency in decision-making though elimination of personal bias in team selection. The positive reviews on the Football Identification Site based on user acceptance evaluation also indicates that the framework is sufficient to serve as the basis of developing an intelligent team management system in different sports, whereby growth and performance of sport players can be monitored and identified.

  16. Psychological predictors of sport injuries among junior soccer players.

    Science.gov (United States)

    Johnson, U; Ivarsson, A

    2011-02-01

    Previous researches have established models that specify psychological factors that could predict sport injuries. One example is Williams and Andersen's stress-injury model stressing factors such as anxiety, negative life stress and few coping resources. The purpose of the current study was to find psychological factors that could lead to an increased injury risk among junior soccer players, in addition to construct an empirical model of injury risk factors for soccer players. The participants were 108 male and female soccer players (m=17, 6) studying at soccer high schools in southwest Sweden. Five questionnaires were used, State Trait Anxiety Inventory, Sport Anxiety Scale, Life Events Survey for Collegiate Athletes, Athletic Coping Skills Inventory-28 and Swedish universities Scales of Personality. Injury record was collected by athletic trainers at the schools during a period of 8 months. The result suggested four significant predictors that together could explain 23% of injury occurrence. The main factors are life event stress, somatic trait anxiety, mistrust and ineffective coping. These findings partly support Williams and Andersen's stress-injury model and are organized into an empirical model. Recommendations are given to sport medicine teams and coaches concerning issues in sport injury prevention.

  17. Kinanthropometry of Group I rugby players in Buenos Aires, Argentina.

    Science.gov (United States)

    Holway, Francis Edward; Garavaglia, Romina

    2009-09-01

    The large variability in size and structure between playing positions in rugby merits specific kinanthropometric profiling. We aim to report detailed descriptive anthropometric data of a sample of 133 rugby players stratified by field positions (age 24.3 +/- 3.6 years, body mass 89.5 +/- 13.2 kg, and stature 178.8 +/- 7.3 cm) belonging to seven Group I teams competing in the Buenos Aires Rugby Union, and to find out if front row forwards (FR) have larger muscle and skeletal parameters. Body composition was analysed with the five-way fractionation method, expressing tissue masses in absolute terms, relative to weight as percentages and to stature as phantom z-scores. Furthermore, somatotype, body mass index, sum of six skinfolds, and muscle-to-bone ratio were calculated. Players were subsequently grouped into three positional clusters and muscular-skeletal elements compared, showing FR to have larger proportional muscle and skeletal structure than remaining forwards and backs (P < 0.001), albeit a similar muscle-to-bone ratio (P = 0.060). When compared to a sample of the top six teams at the 2003 Rugby World Cup, the Buenos Aires players were considerably smaller, measuring, on average, 3-11 cm less in height and 6-13 kg less in weight.

  18. Absence of left ventricular hypertrophy in elite college basketball players.

    Science.gov (United States)

    Wolfe, L A; Martin, R P; Seip, R L

    1985-09-01

    Left ventricular dimensions of 11 successful male college basketball players engaged in pre-season conditioning (mean age, 20.3 years) and 13 tall healthy male controls (mean age, 21.6 years) were studied by echocardiography. Left ventricular internal dimension (LVIDd, mm), posterior wall thickness (PWT, mm), septal thickness (ST, mm), and calculated left ventricular mass (LV mass, g) in the athletes were within or only slightly in excess of echocardiographic normal limits and mean values were not significantly different from the control group. LVIDd (mm/m2 body surface area) was significantly lower in the athletes. However, five guard-type players displayed significantly greater mean values for PWT and LV mass compared to six taller forwards/centers with linear body builds. It was concluded that left ventricular hypertrophy is not a common characteristic of college basketball players. It was hypothesized that cardiac dimensions of young men may vary independently of gross body size in relation to somatotype or other anthropometric variables.

  19. Comparing the Age Related Mood Profile of Veteran Basketball Players

    Directory of Open Access Journals (Sweden)

    Robabeh Rostami

    2016-07-01

    Full Text Available Background: Basketball, as an exciting team sport, is very popular among athletes with disabilities. Among psychological skills, mood states as an important variable have been of special interest to researchers. Objectives: The purpose of the present study was to investigate and compare profile of mood states (BRUMS of disabled former soldiers who play basketball in different age groups. Methodology: After getting permit to conduct the research, 28 disabled basketball players completed the demographic survey and the Brunel Mood Scale (BRUMS questionnaire. BRUMS consisted of 24 items in subscales of stress, anger, depression, fatigue, confusion and vigor. The one-way analysis of variance test was used for the data analysis. The significance level was set at P≤0.05. SPSS Statistics 22.0 was used for the analysis of data. Results: The results showed that mood states become less negative with age. However, scores showed a rising trend in the 35-39 age groups (mood of anger with P=0/02 fatigue with P=0/03 and confusion with P=0/04. Conclusion: It seems that examining the psychological variables in relation to age can help develop more effective strategies in physical and mental training programs for disabled players. Keywords: Mood States, Basketball Players, veteran with disabilities, Age

  20. Play, Create, Share? Console Gaming, Player Production and Agency

    Directory of Open Access Journals (Sweden)

    Olli Sotamaa

    2010-07-01

    Full Text Available Digital games have been frequently used to illustrate the new organisational frameworks that are based on persuading users to carry out tasks and assignments not traditionally associated with them. However coined, ‘user-innovation’ (von Hippel, 2005, ‘crowdsourcing’ (Howe, 2008 or ‘pro-am revolution’ (Leadbeater and Miller, 2004, contemporary examples of this phenomena always include digital games. A closer look at the recent open innovation manifestos reveals that the oft-cited examples come almost entirely from PC games while console games remain mostly non-existent in these texts. It is clear that PC and console games differ both in use and in the cultures they create (Taylor, 2007. Equally, the technological and economic backgrounds of the market sectors have their differences (Kerr, 2006.The concept of LittleBigPlanet, a console game inherently dependent on player production, challenges the neat binary of some much cited arguments about tethered appliances. The first set of research questions rises from this observation. What are the technical and economic constraints and affordances the console as a platform uses to position the productive activities of players? How do these differ from the forms of player production typical of PC gaming (see Sotamaa, 2007a; and Sotamaa, 2007b?

  1. Retention of quiet eye in older skilled basketball players.

    Science.gov (United States)

    Fischer, Lennart; Rienhoff, Rebecca; Tirp, Judith; Baker, Joseph; Strauss, Bernd; Schorer, Jörg

    2015-01-01

    There is mounting research to suggest that cognitive and motor expertise is more resistant to age-related decline than more general capacities. The authors investigated the retention of skills in medium-aged skilled (n = 14) and older-aged skilled (n = 7) athletes by comparing them with medium-aged less skilled (n = 15) and older-aged less skilled (n = 15) participants. Participants performed basketball free throws and dart throws as a transfer task under standardized conditions. Motor performance (accuracy) and perceptual performance (quiet eye) were examined across the four groups. There were significant differences between skill groups and age groups in throwing accuracy on both throwing tasks. Skilled players outperformed less skilled and medium-aged players outperformed older-aged players in basketball and dart throws. There were no significant differences in quiet eye duration across the skill or age groups in either task. These results indicate expertise in a perceptual motor task such as the basketball free throw can be retained in older athletes and that present models of skill maintenance should be re-evaluated to consider the issue of transfer.

  2. Kicking velocity and physical, technical, tactical match performance for U18 female football players - effect of a new ball

    DEFF Research Database (Denmark)

    Andersen, T. Bull; Bendixen, Mads; Pedersen, Jens Meldgaard

    2012-01-01

    We investigated kicking velocity and physical, technical, and tactical match performance for under-18 (U18) female football players and evaluated the effect of using a newly developed lighter smaller ball. Ten regional league teams participated. Maximal ball velocity was 4±1% higher when kicking...... football games, and decrements in running performance occurred towards the end of games. The players kicked faster and reported lower muscular exertion during games played with a lighter smaller ball, but locomotor activities, heart rate and overall technical-tactical game performance remained unaffected....

  3. Performance outcomes after repair of complete achilles tendon ruptures in national basketball association players.

    Science.gov (United States)

    Amin, Nirav H; Old, Andrew B; Tabb, Loni P; Garg, Rohit; Toossi, Nader; Cerynik, Douglas L

    2013-08-01

    A complete rupture of the Achilles tendon is a devastating injury. Variables affecting return to competition and performance changes for National Basketball Association (NBA) players are not readily evident. Players in the NBA who ruptured their Achilles tendons and who underwent surgical repair would have more experience in the league, and the performance of those who were able to return to competition would be decreased when compared with their performance before injury and with their control-matched peers. Cohort study; Level of evidence, 3. Data for 18 basketball players with Achilles tendon repair over a 23-year period (1988-2011) were obtained from injury reports, press releases, and player profiles. Variables included age, body mass index (BMI), player position, and number of years playing in the league. Individual season statistics were obtained, and the NBA player efficiency rating (PER) was calculated for 2 seasons before and after injury. Controls were matched by playing position, number of seasons played, and performance statistics. Univariate and multivariate analyses were performed to assess the effect of each factor. At the time of injury, the average age was 29.7 years, average BMI was 25.6, and average playing experience was 7.6 years. Seven players never returned to play an NBA game, whereas 11 players returned to play 1 season, with 8 of those players returning for ≥2 seasons. Players who returned missed an average of 55.9 games. The PER was reduced by 4.57 (P = .003) in the first season and by 4.38 (P = .010) in the second season. When compared with controls, players demonstrated a significant decline in the PER the first season (P = .038) and second season (P = .081) after their return. The NBA players who returned to play after repair of complete Achilles tendon ruptures showed a significant decrease in playing time and performance. Thirty-nine percent of players never returned to play.

  4. 实施乒乓球新规则十年对我国青少年运动员技战术的影响%Influences of the Ten - year Implementation of New Rules in Table Tennis on China' s Junior Players both technically and tactically

    Institute of Scientific and Technical Information of China (English)

    余胜

    2012-01-01

    运用文献资料法和访谈法剖析了国际乒联“大球”、“11分制”和“无遮挡发球”新规则,具体分析了近十年来乒乓球新规则实行对我国青少年乒乓球训练与比赛的影响,结论表明新规则的出台对我国青少年乒乓球身体、技战术训练比赛和心理训练都有不同程度的影响,并提出在青少年训练中要增强瞬间爆发力和耐力,提高对接发球抢攻和相持阶段训练的重视与合理运用。%By using the methods of literature review and interview, this paper studies the new rule of ITTF big ball, 11 -point and uncovered, analyzes the influence of ten -year implementation of new rule on our junior players. The result shows that the new rule has certain influence on physical and mental, tactical and technical training of our junior players. Based on it, the instantaneous power and endurance during training should be improved, and the training of attack after serving and stalemate phase should be paid attention to and rationally used.

  5. Arthroscopic rotator cuff repair in elite rugby players

    Directory of Open Access Journals (Sweden)

    Tambe Amol

    2009-01-01

    Full Text Available Background: Rugby is an increasingly popular collision sport. A wide spectrum of injuries can be sustained during training and match play. Rotator cuff injury is uncommon in contact sports and there is little published literature on the treatment of rotator cuff tears in rugby players. Aims: We therefore reviewed the results and functional outcomes of arthroscopic rotator cuff repair in elite rugby players. Materials and Methods: Eleven professional rugby players underwent arthroscopic rotator cuff repair at our hospital over a 2-year period. We collected data on these patients from the operative records. The patients were recalled for outcome scoring and ultrasound scans. Results: There were seven rugby league players and four rugby union players, including six internationals. Their mean age was 25.7 years. All had had a traumatic episode during match play and could not return to the game after the injury. The mean time to surgery was 5 weeks. The mean width of the cuff tear was 1.8 cm. All were full- thickness cuff tears. Associated injuries included two Bankart lesions, one bony Bankart lesion, one posterior labral tear, and two 360° labral tears. The biceps was involved in three cases. Two were debrided and a tenodesis was performed in one. Repair was with suture anchors. Following surgery, all patients underwent a supervised accelerated rehabilitation programme. The final follow-up was at 18 months (range: 6-31 months post surgery. The Constant scores improved from 44 preoperatively to 99 at the last follow-up. The mean score at 3 months was 95. The Oxford shoulder score improved from 34 to 12, with the mean third month score being 18. The mean time taken to return to full match play at the preinjury level was 4.8 months. There were no complications in any of the patients and postoperative scans in nine patients confirmed that the repairs had healed. Conclusion: We conclude that full-thickness rotator cuff tears in the contact athlete can

  6. THE STRUCTURE OF MOTOR ABILITIES IN BASKETBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Jadranka Kocić

    2013-07-01

    Full Text Available The expansion of basketball game, just like up-to-date sports results represent the stimulus for further fundamental researches in the aim of improvement scientific and methodological basis of a training work and all other factors connected to the improvement of a training process and top sports creativity. The research was conducted with the aim to determine the specifics of motor abilities in basketball players of the junior rank of competition. All the examinees were male, 16 (+/-6 months years old, 132 in total, all of them were basketball players of the basketball club ”Student” from Nis. The batery of tests for the evaluation of motor abilities included tests for the evaluation of coordination, strength (explosive, repetitive and static, flexibility and stamina and it consisted of 13 motor tests in total. The gained results were processed by the program system for multivariant analysis of data, especially made by Popovic D. for personal computers. The gained results are shown in tables and they give insight into the structure of latent dimensions of basketball players. The motor structure of basketball players is explained by 72.3% of common variance. From the matrix of intercorrelations, four main components were gained. The fist defines tests of static strength, flexibility and repetitive strength; the second is saturated by the test for the evaluation of explosive strength, balance and two tests for the evaluation of repetitive strength. The third is the best explained by the test for the evaluation of balance, flexibility and coordination. The fourth main component is defined by explosive strength. Then, the rotation of components into the oblimin solution is conducted and some better structure of latent dimensions is gained that way. In basketball and other popular sports games in our country, scientific and expert methods and possibilities of scientific fundation of the trainig work are very slowly but surely accepted.The trend

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

    Science.gov (United States)

    Kachel, Kim; Buszard, Tim; Reid, Machar

    2015-01-01

    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.

  8. Determinants of the half-turn with the ball in sub-elite youth soccer players.

    Science.gov (United States)

    Zago, Matteo; Codari, Marina; Grilli, Massimo; Bellistri, Giuseppe; Lovecchio, Nicola; Sforza, Chiarella

    2016-06-01

    We explored the biomechanics of the 180° change-of-direction with the ball (half-turn) in soccer. We aimed at identifying movement strategies which enhance the players' half-turning performance, by characterising technique kinematics and understanding the structure of biomechanical and anthropometrics variables. Ten Under-13 sub-elite male players were recorded with an optoelectronic motion analyser while performing a 5-m straight dribbling followed by a half-turn with the sole. Joints kinematics differences between faster and slower trials were found in support-side hip rotation, driving-side hip adduction, trunk flexion and rotation, and arms abduction. To unveil the data-set structure, a principal component (PC) analysis and a stepwise linear discriminant analysis were performed using 30 biomechanical parameters and four anthropometric variables for each trial. Seven retained PCs explained 79% of the overall variability, featuring combinations of original variables that help in understanding the factors facilitating fast half-turns: keeping short steps, minimising lateral and forward body movements, and centre-of-mass lowering, even with ample lower limbs ranges of motion (RoM); abducting the upper limbs while limiting trunk flexion and pelvic inclination RoM. Balance and task-constrained exercises may be proposed to improve this technique. Moreover, a quantitative knowledge of the movement structure could give coaches objective insights to better instruct young players.

  9. The Long-Term Game: An Analysis of the Life Expectancy of National Football League Players

    Directory of Open Access Journals (Sweden)

    Ruud Koning

    2014-03-01

    Full Text Available The National Football League (NFL has recently received significant negative media attention surrounding the safety of its players, revolving largely around the long term health risks of playing the sport. Recent premature deaths and instances of suicide associated with chronic traumatic encephalopathy and other football related injuries have brought the sport under increased scrutiny. By comparing mortality rates of the general population to mortality rates of players using publically available data from the 1970 and 1994 NFL seasons, we test whether participation in football is significantly harmful to the longevity of the players. We conclude that, in total, players in the NFL have lower mortality rates than the general population. However, there is evidence that line players have higher mortality rates than other players and that those who played more games have higher mortality rates than those who played fewer games.

  10. An outbreak of herpes rugbiorum managed by vaccination of players and sociosexual contacts.

    Science.gov (United States)

    Skinner, G R; Davies, J; Ahmad, A; McLeish, P; Buchan, A

    1996-11-01

    An outbreak of herpes rugbiorum involved nine players including the scrum half and the full back. The infection was characterized by significant constitutional upset with decreased levels of general fitness and match performance for 1-4 months following the outbreak; one player had herpetic lesions on his right eyelid and corneum. Every infected player, 15 non-infected players and five sociosexual contacts received two vaccinations with intracellular subunit vaccine NFU. Ac. HSV-1 (S-MRC5). None of the players or contacts developed cutaneous herpetic recurrence during a follow-up period of 3 years; the player with ocular disease had one recurrence at 30 months following the original episode. These findings encourage consideration of prophylactic or post-exposure vaccination of participants in rugby or other contact sports with this or other appropriate herpes simplex vaccine.

  11. Statistical properties for direction alignment and chasing of players in football games

    CERN Document Server

    Narizuka, Takuma

    2016-01-01

    Focusing on motion of two interacting players in football games, two velocity vectors for the pair of one player and the nearest opponent player exhibit strong alignment. Especially, we find that there exists a characteristic interpersonal distance $ r\\simeq 500 $ cm below which the circular variance for their alignment decreases rapidly. By introducing the order parameter $ \\phi $ in order to measure degree of alignment of players' velocity vectors, we also find that the angle distribution between the above nearest players' velocity vectors changes from the wrapped Cauchy to the mixture of von Mises and wrapped Cauchy distributions at $ \\phi\\simeq 0.7 $. To understand these findings, we construct a simple model with the following two rules: chasing between two players and the reset of the chasing. We numerically show that our model successfully reproduce the results obtained from the actual data. Moreover, from the numerical study, we find that there is another characteristic distance $ r\\simeq 1000 $ cm bel...

  12. Analysis of player's in-game performance vs rating: Case study of Heroes of Newerth

    CERN Document Server

    Caplar, Neven; Matijasevic, Maja

    2013-01-01

    We evaluate the rating system of "Heroes of Newerth" (HoN), a multiplayer online action role-playing game, by using statistical analysis and comparison of a player's in-game performance metrics and the player rating assigned by the rating system. The datasets for the analysis have been extracted from the web sites that record the players' ratings and a number of empirical metrics. Results suggest that the HoN's Matchmaking rating algorithm, while generally capturing the skill level of the player well, also has weaknesses, which have been exploited by players to achieve a higher placement on the ranking ladder than deserved by actual skill. In addition, we also illustrate the effects of the choice of the business model (from pay-to-play to free-to-play) on player population.

  13. A confidence in itself, as mortgage of successful competition activity of the young chess-players

    Directory of Open Access Journals (Sweden)

    Khoroshavina A.V.

    2012-04-01

    Full Text Available Presents the results of the study the basic aspects of self-confidence of young players. The study involved 54 young chess players. Of these, 34 students Kherson CYSS Chess. 20 players from different regions of Ukraine. Age investigated from 10 to 15 years. The dependence of the confidence of participation in competitions for young players on the level of anxiety, motivational set, strong-willed self-control. In the result of performance of young chess players in the competition is directly proportional to the strength of motivation to succeed installation. Most athletes have been observed high levels of self-willed. Self-control depends on the experience of participation of young players in the competition, as well as facilities manager.

  14. Non-invasive Player Experience Estimation from Body Motion and Game Context

    DEFF Research Database (Denmark)

    Burelli, Paolo; Triantafyllidis, George; Patras, Ioannis

    2014-01-01

    . The data collected was analysed and a neural network was trained to find the mapping between player body movements, player in- game behaviour and player experience. The results reveal that some aspects of player experience, such as anxiety or challenge, can be detected with high accuracy (up to 81......In this paper, we investigate on the relationship between player experience and body movements in a non-physical 3D computer game. During an experiment, the participants played a series of short game sessions and rated their experience while their body movements were tracked using a depth camera......%). Moreover, taking into account the playing context, the accuracy can be raised up to 86%. Following such a multi-modal approach, it is possible to estimate the player experience in a non-invasive fashion during the game and, based on this information, the game content could be adapted accordingly....

  15. Physiological Responses of Young Tennis Players to Training Drills and Simulated Match Play.

    Science.gov (United States)

    Gomes, Rodrigo V; Cunha, Vivian C R; Zourdos, Michael C; Aoki, Marcelo S; Moreira, Alexandre; Fernandez-Fernandez, Jaime; Capitani, Caroline D

    2016-03-01

    The aim of this study was to investigate the responses of young tennis players during 5 different training drills and to compare the responses between drills. Ten (17.0 ± 1.2 years) male tennis players participated in this study. Each athlete completed 5 total training drills. Drills 1-4 consisted of each player returning balls from a ball-serving machine and were stroke/time-controlled over 6 points. The fifth drill was a simulated match (SM) play, between 2 opposing players, and also lasted 6 points. The 4 stroke/time-controlled drills had the following strokes/time for each point: drill 1: 2 strokes/∼4 seconds, drill 2: 4 strokes/∼8 seconds, drill 3: 7 strokes/∼14 seconds, drill 4: 10 strokes/∼20 seconds. Peak heart rate (HR), blood lactate concentration (LA), and rating of perceived exertion (RPE) were measured after the first, third, and sixth point of each drill. Drills were performed in a randomized crossover design; a 2-way repeated-measures analysis of variance was used with significance set at p ≤ 0.05. All dependent variables (HR, LA, and RPE) significantly increased (p ≤ 0.05) as strokes, and time per rally increased in each drill. Furthermore, all variables were elevated to a greater magnitude (p ≤ 0.05) during the 7 and 10 stroke drills after the first, third, and sixth points when compared with the SM and the 2 and 4 stroke drills at the corresponding time points. These results suggest that the physiological responses to tennis training drills were stroke/time-dependent. Therefore, because of the intense intermittent nature of tennis, stroke/time-controlled drills, which require significant physiological demands, should be incorporated along with technically focused shorter drills to fully mimic the conditions of competitive match play.

  16. Heart Rate and Energy Expenditure in Division I Field Hockey Players During Competitive Play.

    Science.gov (United States)

    Sell, Katie M; Ledesma, Allison B

    2016-08-01

    Sell, KM and Ledesma, AB. Heart rate and energy expenditure in Division I field hockey players during competitive play. J Strength Cond Res 30(8): 2122-2128, 2016-The purpose of this study was to quantify energy expenditure and heart rate data for Division I female field hockey players during competitive play. Ten female Division I collegiate field hockey athletes (19.8 ± 1.6 years; 166.4 ± 6.1 cm; 58.2 ± 5.3 kg) completed the Yo-Yo intermittent endurance test to determine maximal heart rate. One week later, all subjects wore a heart rate monitor during a series of 3 matches in an off-season competition. Average heart rate (AvHR), average percentage of maximal heart rate (AvHR%), peak exercise heart rate (PExHR), and percentage of maximal heart rate (PExHR%), time spent in each of the predetermined heart rate zones, and caloric expenditure per minute of exercise (kcalM) were determined for all players. Differences between positions (backs, midfielders, and forwards) were assessed. No significant differences in AvHR, AvHR%, PExHR, PExHR%, and %TM were observed between playing positions. The AvHR% and PExHR% for each position fell into zones 4 (77-93% HRmax) and 5 (>93% HRmax), respectively, and significantly more time was spent in zone 4 compared with zones 1, 2, 3, and 5 across all players (p ≤ 0.05). The kcalM reflected very heavy intensity exercise. The results of this study will contribute toward understanding the sport-specific physiological demands of women's field hockey and has specific implications for the duration and schedule of training regimens.

  17. The Relationship Between Perceived Coaching Behaviors, Collective Efficacy and Goal Orientation among fencer players in Turkey

    OpenAIRE

    Turhan TOROS,; Ahmet DUVAN

    2011-01-01

    This paper aims to examine the perceived coaching behaviors, the goal orientation, the the relationship of the collective efficacy among fencer players in Turkey.In this research, the fencer players who played in the fencing teams in 2009-2010 league season and moreover, the ones who took parts in the teams participated into the Turkish National Championship were included. 141 fencer players who participated into the Turkish National Championship were included. In collecting the data, Leaders...

  18. HeapCraft Social Tools: Understanding and Improving Player Collaboration in Minecraft

    OpenAIRE

    Müller, S; Kapadia, M; Frey, S.; Klinger, S; Mann, RP; Solenthaler, B; Sumner, RW; Gross, M.

    2015-01-01

    We introduce a framework to infuence and analyze player collaboration in Minecraft. The framework consists of a telemetry system and several tools to influence player behavior and provide value to server administrators to increase adoption. The data collection includes almost every aspect of gameplay and can be used for analysis beyond player collaboration.1 We started collecting data from several Minecraft servers in March 2015. Most data will be made available to researchers upon request.2 ...

  19. Relationship between Core Stability Muscle Endurance and Static and Dynamic Balance in Basketball Players

    OpenAIRE

    farzaneh saki; masumeh Baghban

    2016-01-01

    Objective: Balancing is the most basic function of the neuromuscular system in performing all simple and complex activities that contribute to health-related physical fitness. Core stability may be a contributing factor to static and dynamic balance. The aim of this study was to investigate the relationship between core stability muscle endurance and static and dynamic balance in basketball players. Methods: 100 basketball players (50 female and 50 male players) were selected randomly bas...

  20. Assessment of Humeral Retroversion Angle in Baseball Players: A Chronological Study

    OpenAIRE

    MAKIUCHI Daisuke:筆頭著者:責任著者; Tsutsui, Hiroaki; MIHARA Kenichi; SUZUKI Kazuhide; NISHINAKA Naoya; Atsumi, Takashi; INAGAKI Katsunori

    2015-01-01

    The objective of this study was to compare the humeral retroversion angles (HRA) between baseball players, including children, and those without a history of playing baseball, clarify the characteristics of the HRA in baseball players, and to determine whether or not chronological changes of the HRA are affected by a throwing motion. We studied 32 young baseball players (Group A), 10 elementary and junior high school students who had never played competitive overhead throwing sports (Group B)...

  1. Three is a crowd – inefficient communication in the multi-player electronic mail game

    OpenAIRE

    Jaegher, K. De; Rosenkranz, S.

    2009-01-01

    In a two-player stag hunt with asymmetric information, players may lock each other into requiring a large number of confirmations and confirmations of confirmations from one another before eventually acting. This intuition has been formalized in the electronic mail game (EMG). The literature provides extensions on the EMG that eliminate inefficient equilibria, suggesting that no formal rules are needed to prevent players from playing inefficiently. The present paper investigates whether these...

  2. Comparison of static and dynamic balance among collegiate cricket, soccer and volleyball male players

    Directory of Open Access Journals (Sweden)

    P Ratan Khuman

    2014-01-01

    Full Text Available Background: Athletes from different sports requires balance control for their better performance depending on game type they involved. When prescribing balance exercises to athletes in different sports, it may be important to recognize performance variations. Objective: The objective of the present study was to compare the static and dynamic balance among collegiate cricket, soccer and volleyball male players. Materials and Methods: A total of 150 students, college level male players from five different colleges were requited for the study with purposive sampling. They were assigned into three different groups according to their types of sports, cricket n = 50, soccer n = 50, volleyball n = 50. The static and dynamic balance was assessed using flamingo balance test (FBT and star excursion balance test (SEBT in institutional based sports physiotherapy department. Results: Intra-group comparison for FBT and SEBT score shows no significance difference (P > 0.05. Multiple comparison of FBT and SEBT score between groups reveals significantly difference between cricket and soccer player (P = 0.000, between cricket and volleyball player (P = 0.000 and between soccer player and volleyball players (P = 0.000. FBT and SEBT score were significantly higher in soccer players than volleyball and cricketer were found to have the least score compared with soccer and volleyball players. Conclusion: There is significance difference in static and dynamic balance among collegiate cricket, soccer and volleyball male players. The soccer players demonstrate higher balance than volleyball players and the volleyball players have a higher balance than that of cricketers both statically and dynamically.

  3. Prevalence and variance of shoulder injuries in elite collegiate football players.

    Science.gov (United States)

    Kaplan, Lee D; Flanigan, David C; Norwig, John; Jost, Patrick; Bradley, James

    2005-08-01

    Shoulder injuries are the fourth most common musculoskeletal injury encountered in American football players. There is little information in the literature on the role of playing position in the type of shoulder injuries seen. There is a high prevalence of shoulder injuries in elite collegiate American football players, with type of injury varying by playing position. Cohort study (prevalence); Level of evidence, 3. A total of 336 elite collegiate American football players were invited to the National Football League Combine for physical testing and medical evaluation. Current and historical data were evaluated for the purpose of this study, and all players underwent radiographic examinations, including plain radiographs and/or magnetic resonance imaging when necessary. All shoulder pathological conditions and shoulder surgical procedures were recorded. Players were categorized by position for the analysis of position-specific trends. Of the players, 50% had a history of shoulder injuries, with a total of 226 shoulder injuries (1.3 injuries per player injured); 56 players (34%) had a total of 73 surgeries. The most common injuries were acromioclavicular separation (41%), anterior instability (20%), rotator cuff injury (12%), clavicle fracture (4%), and posterior instability (4%). The most common surgeries performed were anterior instability reconstruction (48%), Mumford/Weaver-Dunn surgery (15%), posterior instability surgery (10%), and rotator cuff surgery (10%). Shoulder injuries were more common in quarterbacks and defensive backs. Surgery was more common in linebackers or linemen. A history of anterior instability was more common in defensive players, with surgery required 76% of the time. Linemen had more rotator cuff injuries and posterior instability than players in other positions. Shoulder injuries are common injuries in elite collegiate football players, with one-third undergoing surgical procedures. There are definitive trends in the types of injuries

  4. Pre-training perceived wellness impacts training output in Australian football players.

    Science.gov (United States)

    Gallo, Tania F; Cormack, Stuart J; Gabbett, Tim J; Lorenzen, Christian H

    2016-08-01

    The impact of perceived wellness on a range of external load parameters, rating of perceived exertion (RPE) and external load:RPE ratios, was explored during skill-based training in Australian footballers. Fifteen training sessions involving 36 participants were analysed. Each morning before any physical training, players completed a customised perceived wellness questionnaire (sleep quality, fatigue, stress, mood and muscle soreness). Microtechnology devices provided external load (average speed, high-speed running distance, player load and player load slow). Players provided RPE using the modified Borg category-ratio 10 RPE scale. Mixed-effect linear models revealed significant effects of wellness Z-score on player load and player load slow. Effects are reported with 95% confidence limits. A wellness Z-score of -1 corresponded to a -4.9 ± 3.1 and -8.6 ± 3.9% reduction in player load and player load slow, respectively, compared to those without reduced wellness. Small significant effects were also seen in the average speed:RPE and player load slow:RPE models. A wellness Z-score of -1 corresponded to a 0.43 ± 0.38 m·min(-1) and -0.02 ± 0.01 au·min(-1) change in the average speed:RPE and player load slow:RPE ratios, respectively. Magnitude-based analysis revealed that the practical size of the effect of a pre-training perceived wellness Z-score of -1 would have on player load slow was likely negative. The results of this study suggests that monitoring pre-training perceived wellness may provide coaches with information about the intensity of output that can be expected from individual players during a training session.

  5. A Proposal to Address NFL Club Doctors' Conflicts of Interest and to Promote Player Trust.

    Science.gov (United States)

    Cohen, I Glenn; Lynch, Holly Fernandez; Deubert, Christopher R

    2016-11-01

    How can we ensure that players in the National Football League receive excellent health care they can trust from providers who are as free from conflicts of interest as realistically possible? NFL players typically receive care from the club's own medical staff. Club doctors are clearly important stakeholders in player health. They diagnose and treat players for a variety of ailments, physical and mental, while making recommendations to the player concerning those ailments. At the same time, club doctors have obligations to the club, namely to inform and advise clubs about the health status of players. While players and clubs share an interest in player health-both of them want players to be healthy so they can play at peak performance-there are several areas where their interests can diverge, and the divergence presents legal and ethical challenges. The current structure forces club doctors to have obligations to two parties-the club and the player-and to make difficult judgments about when one party's interests must yield to another's. None of the three parties involved should prefer this conflicted approach. We propose to resolve the problem of dual loyalty by largely severing the club doctor's ties with the club and refashioning that role into one of singular loyalty to the player-patient. The main idea is to separate the roles of serving the player and serving the club and replace them with two distinct sets of medical professionals: the Players' Medical Staff (with exclusive loyalty to the player) and the Club Evaluation Doctor (with exclusive loyalty to the club). We begin by explaining the broad ethical principles that guide us and that help shape our recommendation. We then provide a description of the role of the club doctor in the current system. After explaining the concern about the current NFL player health care structure, we provide a recommendation for improving this structure. We then discuss how the club medical staff fits into the broader

  6. The Relative Age Effect and Physical Fitness Characteristics in German Male Tennis Players

    Directory of Open Access Journals (Sweden)

    Alexander Ulbricht, Jaime Fernandez-Fernandez, Alberto Mendez-Villanueva, Alexander Ferrauti

    2015-09-01

    Full Text Available The aims of the study were to test: 1 whether the relative age effect (RAE was prevalent in young (U12-U18 German male tennis players; 2 the potential influence of age and/or skill level on RAE and 3 whether maturity, anthropometric and fitness measures vary according to birth date distribution in elite youth tennis players. For the present study the following male populations were analysed: Overall German population (n = 3.216.811, all players affiliated to the German Tennis Federation (DTB (n = 120.851, players with DTB official ranking (n = 7165, regional (n = 381 and national (n = 57 squads (11-17 years old, as well as the top 50 German senior players were analyzed. RAEs were more prevalent at higher competitive levels with more players born in the first quarter of the year compared with the reference population for ranked (29.6%, regional (38.1% and national (42.1% players. No systematic differences were found in any of the maturity, anthropometric and fitness characteristics of the regional squad players born across different quarters. RAEs are present in the DTB competitive system and it was more pronounced at higher competitive levels. Compared with early born, late born players who were selected into elite squads did not differ in maturation, anthropometric and fitness characteristics.

  7. Lack of blood pressure difference by race in professional American football players.

    Science.gov (United States)

    Tucker, Andrew M; Lincoln, Andrew E; Vogel, Robert A; Black, Henry R; Dunn, Reginald E; Wilson, Peter W F; Pellman, Elliot J

    2015-05-01

    Previous findings suggest that professional American football players have higher blood pressures (BP) and a higher prevalence of pre-hypertension and hypertension than the general population. We sought to determine whether race is associated with differences in BP and prevalence of pre-hypertension and hypertension among a large sample of professional football players. BP was measured at 2009 team mini-camps for 1484 black (n = 1007) and white (n = 477) players from 27 National Football League (NFL) teams. Players were categorized into three position groups based on body mass index (BMI). There was no racial difference in mean systolic or diastolic BP in any of the three position groups. There were no racial differences in prevalence of hypertension (99 [9.8%] black players vs. 39 [8.2%] white players; P = .353) or pre-hypertension (557 [55.3%] black players vs. 264 [55.3%] white players; P = 1.0). Contrary to findings in the general population, BP and prevalence of pre-hypertension/hypertension did not vary with race in a large population of active NFL players.

  8. Reference Values and Gender Differences of the Functional Parameters in Romanian Elite Junior Tennis Players

    Directory of Open Access Journals (Sweden)

    Adrian NAGEL

    2013-06-01

    Full Text Available Purpose: To establish the reference values and gender differences regarding fitness, strength, and time reaction of the Romanian elite junior tennis players. Material and Methods: Thirty four junior tennis players (19 male, 15 female with a mean age of 15 years were selected from the database of the Cardiopulmonary Effort Testing and Physical Performance Laboratory from Faculty of Physical Education and Sport, West University of Timisoara. To be included in the study, a tennis player had to belong to the Romanian Tennis Federation as a junior, be among the 50 best players in his/her category, and have no pathology at the evaluation moment. All subjects underwent functional evaluation by performing a maximal cardiopulmonary exercise test, the counter movement jump test and complex opto-acoustic reaction test. Results: The functional performance are significantly different for males and females in all parameters studied, with male tennis players showing better performance than female tennis players. Conclusions: The mean values of functional parameters of the Romanian elite junior tennis players are lower than international competitive tennis athletes. There are significant gender differences in junior tennis players. We hope that the present study results provide useful reference values for coaches and physical trainers in order to improve functional performance of their junior tennis players.

  9. Cumulative Incidence of Osteochondritis Dissecans of the Capitellum in Child and Adolescent Baseball Players

    OpenAIRE

    Iwame, Toshiyuki; Matsuura, Tetsuya; Suzue, Naoto; Sairyo, Koichi

    2016-01-01

    Objectives: Prevalence of osteochondritis dissecans (OCD) of the capitellum is high among individuals who have played baseball since childhood. Recently two cross-sectional studies according to prevalence of OCD have been published. In a study of 1040 baseball players aged 10 to 12 years, Matsuura et al found that 2.1% of players had OCD, with no differences in prevalence according to age or player position. Kida et al., in their study of 2433 baseball players aged 12 to 18 years, found OCD i...

  10. Self-appraisal of hockey players of high class of different playing position

    Directory of Open Access Journals (Sweden)

    Oleksiy Mikhnov

    2014-12-01

    Full Text Available Purpose: to expose the features of display of self-appraisal for the hockey players of high class of different playing position. Material and Methods: for the exposure of level of self-appraisal for hockey players, information of sportsmen of high class, taking part in the matches of the Kontinental hockey league (KHL in a season 2013–2014 was probed sixteen hockey players, having a sporting digit MS and MSWC, took part in researches. Methods were used: pedagogical supervision, pedagogical analysis and generalization of front-rank experience, psychological testing, analysis of data of the special scientific-methodical literature, expert questioning, an analysis of data is the Internet. Results: findings allowed to set that the players of line of attack (central and extreme forward have more high level of self-appraisal for certain, than players of defence and hockey goalkeepers. This tendency is looked over both on the separate constituents of self-appraisal and on the whole on all spectrums of the studied indexes. The got results of researches rotined that the hockey players of high class had or middle or high level of self-appraisal. Among testable hockey players, players were not exposed with the low level of self-appraisal. Conclusions: the exposed distinctions in the level of self-appraisal of hockey players of high class can be used for diagnostics of playing predisposition and choice of playing line of business in a command.

  11. A Game-based Corpus for Analysing the Interplay between Game Context and Player Experience

    DEFF Research Database (Denmark)

    Shaker, Noor; Yannakakis, Georgios N.; Asteriadis, Stylianos;

    2011-01-01

    Recognizing players' aective state while playing video games has been the focus of many recent research studies. In this paper we describe the process that has been followed to build a corpus based on game events and recorded video sessions from human players while playing Super Mario Bros. We...... present dierent types of information that have been extracted from game context, player preferences and perception of the game, as well as user features, automatically extracted from video recordings.We run a number of initial experiments to analyse players' behavior while playing video games as a case...

  12. Hack-proof Synchronization Protocol for Multi-player Online Games

    Science.gov (United States)

    Fung, Yeung Siu; Lui, John C. S.

    Modern multi-player online games are popular and attractive because they provide a sense of virtual world experience to users: players can interact with each other on the Internet but perceive a local area network responsiveness. To make this possible, most modern multi-player online games use similar networking architecture that aims to hide the effects of network latency, packet loss, and high variance of delay from players. Because real-time interactivity is a crucial feature from a player's point of view, any delay perceived by a player can affect his/her performance [16]. Therefore, the game client must be able to run and accept new user commands continuously regardless of the condition of the underlying communication channel, and that it will not stop responding because of waiting for update packets from other players. To make this possible, multi-player online games typically use protocols based on "dead-reckoning" [5, 6, 9] which allows loose synchronization between players.

  13. Physical and physiological attributes of female volleyball players--a review.

    Science.gov (United States)

    Lidor, Ronnie; Ziv, Gal

    2010-07-01

    The main objective of this article was to review a series of studies (n = 31) on physical attributes, physiological attributes, and on-court performances of female volleyball players. Empirical and practical knowledge emerging from studies on training-related issues in volleyball, such as body mass, fat-free mass, aerobic profile, strength, and agility and speed, should be integrated and applied when planning annual training programs for volleyball players. Based on our review, it was found that (a) players of a higher skill level are taller, somewhat heavier, and have higher vertical jump values than players of a lower level; (b) the aerobic profile of female volleyball players is similar to that of female basketball players; (c) ballistic resistance training can increase vertical jump values in female volleyball players; and (d) preseason conditioning should be conducted to prevent fatigue and reduced performance at the beginning of the season. Among the research concerns discussed in the article are that there is a lack data for on-court performance and time-motion analysis in female volleyball players and that more experimental/manipulative studies are needed to examine the effectiveness of different training programs on physiological attributes of female volleyball players. Two practical implications are suggested for volleyball and strength and conditioning coaches: (a) functional and nonfunctional overreaching should be carefully monitored when planning strength and conditioning programs, and (b) volleyball programs should include ballistic-type training.

  14. Anthropometric, body composition and somatotype characteristics of elite female volleyball players from the highest Spanish league.

    Science.gov (United States)

    Martín-Matillas, Miguel; Valadés, David; Hernández-Hernández, Elena; Olea-Serrano, Fátima; Sjöström, Michael; Delgado-Fernández, Manuel; Ortega, Francisco B

    2014-01-01

    This study aimed to describe morphological characteristics of elite female volleyball players from the highest Spanish league, with special focus on differences by performance level and playing positions. Nearly all female players playing in the highest Spanish volleyball league during season 2003/2004 participated in this study (N=148 elite players, 92% of the total). Anthropometric, body composition and somatotype parameters according to performance and playing positions were analysed. The players' characteristics were as follows; body mass 72.3 ± 8.4 kg; stature 179.8 ± 7.1 cm; body fat 24.0 ± 3.1% and skeletal muscle mass 27.3 ± 2.9 kg. Mean somatotype was 3.1 ± 0.7; 3.4 ± 0.9; 3.1 ± 0.9 characterised as central with a tendency to balanced mesomorph. Top level players (whose teams were better classified in the team performance ranking) were taller, had higher skeletal muscle mass and ectomorphy, and had a lower level of adiposity markers, compared with lower level players. Players selected for their respective National teams (individual performance) were taller, heavier, had higher muscle mass and lower endomorphy than non-selected players. Differences according to playing positions were found. This study provides a complete set of reference data on anthropometry, body composition and somatotype of elite female volleyball players. Morphological differences have been identified according to performance level and playing position.

  15. CUE USAGE IN VOLLEYBALL: A TIME COURSE COMPARISON OF ELITE, INTERMEDIATE AND NOVICE FEMALE PLAYERS

    Science.gov (United States)

    Vaeyens, R; Zeuwts, L; Philippaerts, R; Lenoir, M

    2014-01-01

    This study compared visual search strategies in adult female volleyball players of three levels. Video clips of the attack of the opponent team were presented on a large screen and participants reacted to the final pass before the spike. Reaction time, response accuracy and eye movement patterns were measured. Elite players had the highest response accuracy (97.50 ± 3.5%) compared to the intermediate (91.50 ± 4.7%) and novice players (83.50 ± 17.6%; pvolleyball and suggests that expert players extract more information from parafoveal regions. PMID:25609887

  16. EFFECTS OF WHOLE BODY VIBRATION ON STRENGTH AND JUMPING PERFORMANCE IN VOLLEYBALL AND BEACH VOLLEYBALL PLAYERS

    Science.gov (United States)

    Zmijewski, P.; Jimenez-Olmedo, J.M.; Jové-Tossi, M.A.; Martínez-Carbonell, A.; Suárez-Llorca, C.; Andreu-Cabrera, E.

    2014-01-01

    The primary aim of this study was to examine the effects of 6-week strength training with whole body vibration (WBV) on leg strength and jumping performance in volleyball and beach volleyball players. Twenty-three sub-elite male volleyball (VB; n=12) and beach volleyball players (BVB; n=11) aged 21.2±3.0 years were divided into two groups and subjected to 6 weeks of strength training (three one-hour sessions per week): (I) 12 players (6 VB and 6 BVB players) underwent training with WBV (30-40 Hz, 1.7-2.5 mm, 3.0-5.7 g), and (II) 11 players (6 VB and 5 BVB players) underwent traditional strength training. Squat jump (SJ) and countermovement squat jump (CMJ) measurements by the Ergo Tester contact platform and maximum leg press test (1RM) were conducted. Three-factor (2 time x 2 WBV use x 2 discipline) analysis of variance for SJ, CMJ and 1RM revealed a significant time main effect (pvolleyball and beach volleyball players increases leg strength more and leads to greater improvement in jump performance than traditional strength training, but greater improvements can be expected in beach volleyball players than in volleyball players. PMID:25187676

  17. ANALYSIS OF SELECTION INDICATORS OF BADMINTON PLAYERS BY THE DELPHI METHOD AND ANALYTIC HIERARCHY PROCESS

    National Research Council Canada - National Science Library

    Han-Chen Huang; Chun-Ta Lin; Chia-Sen Hu

    2015-01-01

    .... The researcher then interviewed badminton coaches and applied Analytic Hierarchy process (AHP) to determine the importance of the indicators of potential badminton players for badminton coaches...

  18. Lumbar Mechanics in Tennis Groundstrokes: Differences in Elite Adolescent Players With and Without Low Back Pain.

    Science.gov (United States)

    Campbell, Amity; Straker, Leon; Whiteside, David; O'Sullivan, Peter; Elliott, Bruce; Reid, Machar

    2016-02-01

    Adolescent tennis players are at risk for low back pain (LBP). Recent research has demonstrated a potential mechanical etiology during serves; however, groundstrokes have also been suggested to load this region. Therefore, this study compared lumbar mechanics between players with and without a history of LBP during open and square stance tennis forehands and backhands. Nineteen elite, adolescent, male tennis players participated, 7 with a history of recurrent disabling LBP and 12 without. Differences in three-dimensional lumbar kinetics and kinematics were compared between pain/no pain groups and groundstrokes using linear mixed models (P tennis players.

  19. Research of individual psychological particular qualities handball players 15-17 years.

    Directory of Open Access Journals (Sweden)

    Bikova H.O.

    2011-02-01

    Full Text Available The differences of individual-psychological characteristics of young handball players playing in different game roles. It is shown the relationship of certain personality characteristics of athletes with a line of attack handball players. In research took part handball players at the age of 15-17 years. It is analyzed data from questionnaires by R. Kettela and R. Rusalova. Evaluated the differences in the properties of the temperament handball players of different roles. Established that the distribution of game functions athletes must take into account their individual psychological characteristics.

  20. Nutrient intake and blood iron status of male collegiate soccer players.

    Science.gov (United States)

    Noda, Yuka; Iide, Kazuhide; Masuda, Reika; Kishida, Reina; Nagata, Atsumi; Hirakawa, Fumiko; Yoshimura, Yoshitaka; Imamura, Hiroyuki

    2009-01-01

    The purpose of this study was: 1) to collect baseline data on nutrient intake in order to advise athletes about nutrition practices that might enhance performance, and 2) to evaluate the dietary iron intake and blood iron status of Japanese collegiate soccer players. The subjects were 31 soccer players and 15 controls. Dietary information was obtained with a food frequency questionnaire. The mean carbohydrate (6.9 g.kg-1 BW) and protein (1.3 g/kg) intakes of the soccer players were marginal in comparisons with recommended targets. The mean intakes of calcium, magnesium, vitamin A, B1, B2, and C were lower than the respective Japanese recommended dietary allowances (RDAs) or adequate dietary intakes in the soccer players. The mean intakes of green and other vegetables, milk and dairy products, fruits, and eggs were lower than the recommended targets. Thus, we recommended athletes to increase the intake of these foodstuffs along with slight increase in carbohydrate and lean meat. The mean intake of iron was higher than the respective RDA in the soccer players. A high prevalence of hemolysis (71%) in the soccer players was found. None of the soccer players and controls had anemia. Two soccer players had iron depletion, while none was found in the controls. In those players who had iron deficiency, the training load need to be lowered and/or iron intake may be increased.

  1. Player Load, Acceleration, and Deceleration During Forty-Five Competitive Matches of Elite Soccer.

    Science.gov (United States)

    Dalen, Terje; Ingebrigtsen, Jørgen; Ettema, Gertjan; Hjelde, Geir Havard; Wisløff, Ulrik

    2016-02-01

    The use of time-motion analysis has advanced our understanding of position-specific work rate profiles and the physical requirements of soccer players. Still, many of the typical soccer activities can be neglected, as these systems only examine activities measured by distance and speed variables. This study used triaxial accelerometer and time-motion analysis to obtain new knowledge about elite soccer players' match load. Furthermore, we determined acceleration/deceleration profiles of elite soccer players and their contribution to the players' match load. The data set includes every domestic home game (n = 45) covering 3 full seasons (2009, 2010, and 2011) for the participating team (Rosenborg FC), and includes 8 central defenders (n = 68), 9 fullbacks (n = 83), 9 central midfielders (n = 70), 7 wide midfielders (n = 39), and 5 attackers (A, n = 50). A novel finding was that accelerations contributed to 7-10% of the total player load for all player positions, whereas decelerations contributed to 5-7%. Furthermore, the results indicate that other activities besides the high-intensity movements contribute significantly to the players' total match workload. Therefore, motion analysis alone may underestimate player load because many high-intensity actions are without a change in location at the pitch or they are classified as low-speed activity according to current standards. This new knowledge may help coaches to better understand the different ways players achieve match load and could be used in developing individualized programs that better meet the "positional physical demands" in elite soccer.

  2. Performance of future elite players at the NFL Scouting Combine.

    Science.gov (United States)

    Hedlund, David P

    2017-09-11

    The purpose of this study is to examine players' physical and performance measures taken at the NFL Scouting Combine and compare these to their future performance in the NFL. From 2002-2016, three types of player data (N=5,506) were collected from secondary data sources. Results players earned on various NFL Scouting Combine drills and measurements (e.g., height, weight, 40-yard dash time, vertical jump, bench press repetitions, shuttle run time, and 3-cone drill time), the position players play on the field (e.g., quarterback, running back, wide receiver, tight end, offensive line, defensive line, linebacker, and defensive back), and if players received elite performance awards (e.g., Pro Bowl and All-Pro selections) in the future were collected. After analyzing the data, the results indicate that (1) NFL quarterbacks that received All-Pro and Pro Bowl awards tend to be taller, weigh more, run faster in the 40-yard dash, jump higher, complete more bench presses, and are slower for the shuttle run and 3-cone drill; (2) All-Pro and Pro Bowl NFL running backs tend to weight more, run the 40-yard dash faster, do not jump as high, complete more bench presses, and complete the shuttle run and 3-cone drills slower; (3) NFL wide receivers that were selected for the Pro Bowl or as All-Pros tend to be taller, weigh more, run the 40-yard dash faster, have a higher vertical jump, and run the 3-cone drill faster; (4) NFL tight ends that received All-Pro and Pro Bowl awards tend to be taller, weight more, run the 40-yard dash faster, jump higher, complete more bench presses, run the shuttle run slower, and complete the 3-cone drill faster; (5) All-Pro and Pro Bowl NFL offensive linemen tend to run the 40-yard dash faster, jump higher, are able to complete more bench presses, and run both the shuttle run and 3-cone drill faster; (6) NFL defensive linemen that were selected as All-Pro and Pro Bowl players tend to be taller, weight more, run the 40-yard dash faster, jump higher

  3. The tennis player in wheel chair: players‘ categories

    Directory of Open Access Journals (Sweden)

    David Sanz Rivas

    2002-12-01

    Full Text Available The objective of this article is to offer a typology of disabled tennis players who practice the sport activity in a wheelchair. First, some brief references concerning physical disability are included, an expression whose meaning includes wheelchair tennis players, which is defi ned as an individual who, as a consequence ofa congenital or acquired defi ciency, is impeded of accomplishing, with normality, the basic forms of movement. The three situations dealt with in the text, which come to describe the points mentioned in the “Introduction”, comprise, respectively, of a classifi cation of the physical disabilities which are linked to the different sequelae presented (neurological, myopathic, orthopedic and rheumatic, a summary of the types of marrow injuries (with an indication of the muscle groups involved and the movements affected, and the different situations that demonstrate sequelae caused by marrow injuries, varying in function of number and class of the extremities affected (from monoplegia to quadriplegia, via paraplegia, triplegia, hemiplegia and diplegia. The thematic nucleus of this work is a description of the several categories of tennis players in wheelchairs which should establish in function of their limitations; namely: paraplegic sportsmen, tetraplegic, players with cerebral paralysis, athletes with spina bifida, players with poliomyelitis and players with amputated lower limbs. Examples are used to illustrate ,the points, complementing the theoretical references. RESUMO O presente artigo tem o objetivo de oferecer uma tipologia de jogadores portadores de defi ci��ncia física que praticam a atividade desportiva do tênis em cadeira de rodas. Incluem-se a princípio, umas breves referências concernentes ao defi ciente físico, expressões cujo referente signifi cativo inclui o jogador de tênis em cadeira de rodas, que fi ca defi nido como aquele indivíduo que, como conseqüência de uma defi ciência congênita ou

  4. Injury frequency and body composition of elite Romanian rugby players

    Directory of Open Access Journals (Sweden)

    Bogdan ALMĂJAN-GUȚĂ

    2017-03-01

    Full Text Available Background: The physical exertion in the game of rugby is intense and depends on the playing position. This study hypothesized that peculiarities of body composition are important and should be properly interpreted in order to improve fitness and particularly in order to reduce the risk of injuries. Purpose: The aim of the present paper is to highlight the importance of body composition evaluation and to underline the usefulness of the data thus obtained for both training individualization and sports injuries risk reduction. Material and Methods: Thirty seven senior male rugby players from the former Romanian national team were assessed on body composition using a segmental multi-frequency bio-impedance analyzer InBody 720 (The Body Composition Analyzer – South Korea. We compared the results from both the preseason and the regular season 2012 with the international norms for elite players and we categorized the data by playing positions. Results: We have analyzed the amount of lean mass on each limb (kg, body water content (l, percentage of body fat, bone mineral and protein content (kg. We observed that the number of injuries is directly correlated to high levels of body fat percentage, low lean mass, and edema scores. Conclusions: The risk of injury can be identified among elite rugby players not only by using fitness tests, but also by using a simple and objective test of body composition. These results show how important it is to monitor the level of body fat, lean muscle mass and muscular development in order to modify nutrition and food habits, individualize trainings and thus reduce the number of injuries.

  5. Anthropometric and Physical Profiles of English Academy Rugby Union Players.

    Science.gov (United States)

    Darrall-Jones, Joshua D; Jones, Ben; Till, Kevin

    2015-08-01

    The purpose of this study was to evaluate the anthropometric and physical characteristics of English regional academy rugby union players by age category (under 16s, under 18s and under 21s). Data were collected on 67 academy players at the beginning of the preseason period and comprised anthropometric (height, body mass, and sum of 8 skinfolds) and physical (5-, 10-, 20-, and 40-m sprint, acceleration, velocity, and momentum; agility 505; vertical jump; Yo-Yo intermittent recovery test level 1; 30-15 intermittent fitness test; absolute and relative 3 repetition maximum front squat, split squat, bench press, prone row, and chin; and isometric mid-thigh pull). One-way analysis of variance demonstrated significant increases across the 3 age categories (p ≤ 0.05) for height (e.g., 16s = 178.8 ± 7.1; 18s = 183.5 ± 7.2; 21s = 186.7 ± 6.61 cm), body mass (e.g., 16s = 79.4 ± 12.8; 18s = 88.3 ± 11.9; 21s = 98.3 ± 10.4 kg), countermovement jump height and peak power, sprint momentum, velocity, and acceleration; absolute, relative, and isometric (e.g., 16s = 2,157.9 ± 309.9; 18s = 2,561.3 ± 339.4; 21s = 3,104.5 ± 354.0 N) strength. Momentum, maximal speed, and the ability to maintain acceleration were all discriminating factors between age categories, suggesting that these variables may be more important to monitor rather than sprint times. These findings highlight that anthropometric and physical characteristics develop across age categories and provide comparative data for English Academy Rugby Union players.

  6. Short Duration Heat Acclimation in Australian Football Players

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    Monica Kelly, Paul B. Gastin, Daniel B Dwyer, Simon Sostaric, Rodney J. Snow

    2016-03-01

    Full Text Available This study examined if five sessions of short duration (27 min, high intensity, interval training (HIIT in the heat over a nine day period would induce heat acclimation in Australian football (AF players. Fourteen professional AF players were matched for VO2peak (mL·kg-1·min-1 and randomly allocated into either a heat acclimation (Acc (n = 7 or Control (Con group (n = 7. The Acc completed five cycle ergometer HIIT sessions within a nine day period on a cycle ergometer in the heat (38.7 ± 0.5 °C; 34.4 ± 1.3 % RH, whereas Con trained in thermo-neutral conditions (22.3 ± 0.2 °C; 35.8 ± 0. % RH. Four days prior and two days post HIIT participants undertook a 30 min constant load cycling test at 60% VO2peak in the heat (37.9 ± 0.1 °C; 28.5 ± 0.7 % RH during which VO2, blood lactate concentration ([Lac-], heart rate (HR, rating of perceived exertion (RPE, thermal comfort, core and skin temperatures were measured. Heat acclimation resulted in reduced RPE, thermal comfort and [Lac-] (all p < 0.05 during the submaximal exercise test in the heat. Heart rate was lower (p = 0.007 after HIIT, in both groups. Heat acclimation did not influence any other measured variables. In conclusion, five short duration HIIT sessions in hot dry conditions induced limited heat acclimation responses in AF players during the in-season competition phase. In practice, the heat acclimation protocol can be implemented in a professional team environment; however the physiological adaptations resulting from such a protocol were limited.

  7. Sleep Hygiene and Recovery Strategies in Elite Soccer Players.

    Science.gov (United States)

    Nédélec, Mathieu; Halson, Shona; Delecroix, Barthélémy; Abaidia, Abd-Elbasset; Ahmaidi, Said; Dupont, Gregory

    2015-11-01

    In elite soccer, players are frequently exposed to various situations and conditions that can interfere with sleep (e.g., playing night matches interspersed with 3 days; performing activities demanding high levels of concentration close to bedtime; use of products containing caffeine or alcohol in the period preceding bedtime; regular daytime napping throughout the week; variable wake-up times or bedtime), potentially leading to sleep deprivation. We outline simple, practical, and pharmaceutical-free sleep strategies that are coordinated to the constraints of elite soccer in order to promote sleep. Sleep deprivation is best alleviated by sleep extension; however, sleep hygiene strategies (i.e., consistent sleep pattern, appropriate napping, and active daytime behaviors) can be utilized to promote restorative sleep. Light has a profound impact on sleep, and sleep hygiene strategies that support the natural environmental light-dark cycle (i.e., red-light treatment prior to sleep, dawn-simulation therapy prior to waking) and prevent cycle disruption (i.e., filtering short wavelengths prior to sleep) may be beneficial to elite soccer players. Under conditions of inordinate stress, techniques such as brainwave entrainment and meditation are promising sleep-promoting strategies, but future studies are required to ascertain the applicability of these techniques to elite soccer players. Consuming high-electrolyte fluids such as milk, high-glycemic index carbohydrates, some forms of protein immediately prior to sleep, as well as tart cherry juice concentrate and tryptophan may promote rehydration, substrate stores replenishment, muscle-damage repair and/or restorative sleep. The influence of cold water immersion performed close to bedtime on subsequent sleep is still debated. Conversely, the potential detrimental effects of sleeping medication must be recognized. Sleep initiation is influenced by numerous factors, reinforcing the need for future research to identify such

  8. Isokinetic evaluation of knee muscles in soccer players: discriminant analysis

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    Bruno Fles Mazuquin

    2015-10-01

    Full Text Available ABSTRACTIntroduction:Muscle activity in soccer players can be measured by isokinetic dynamometer, which is a reliable tool for assessing human performance.Objectives:To perform isokinetic analyses and to determine which variables differentiate the under-17 (U17 soccer category from the professional (PRO.Methods:Thirty four players were assessed (n=17 for each category. The isokinetic variables used for the knee extension-flexion analysis were: peak torque (Nm, total work (J, average power (W, angle of peak torque (deg., agonist/ antagonist ratio (%, measured for three velocities (60°/s, 120°/s and 300°/s, with each series containing five repetitions. Three Wilks' Lambda discriminant analyses were performed, to identify which variables were more significant for the definition of each of the categories.Results:The discriminative variables at 60°/s in the PRO category were: extension peak torque, flexion total work, extension average power and agonist/antagonist ratio; and for the U17s were: extension total work, flexion peak torque and flexion average power. At 120°/s for the PRO category the discriminant variables were: flexion peak torque and extension average power; for the U17s they were: extension total work and flexion average power. Finally at 300°/s, the variables found in the PRO and U17 categories respectively were: extension average power and extension total work.Conclusion:Isokinetic variables for flexion and extension knee muscles were able to significantly discriminate between PRO and U17 soccer players.

  9. Isokinetic Strength Profile of Elite Female Handball Players

    Directory of Open Access Journals (Sweden)

    Xaverova Zuzana

    2015-12-01

    Full Text Available Systematic assessment of muscle strength of the lower extremities throughout the annual training cycle in athletes is crucial from a performance perspective for the optimization of the training process, as well as a health perspective with regard to injury prevention. The main aim of the present study was to determine isokinetic muscle strength of the knee flexors and extensors in female handball players at the beginning of a preparatory period and to assess whether there were any differences between players of different performance levels. The performance level was expressed by means of membership of the Women’s Junior National Handball Team (JNT, n=8 or the Women’s National Handball Team (NT, n=9. The isokinetic peak torque during concentric and eccentric single-joint knee flexion and extension was measured at angular velocities of 60, 180, 240°/s (concentric and 60°/s (eccentric. The Mann- Whitney test showed no significant differences in the peak torques or ipsilateral ratios between the two groups. The bilateral force deficit (BFD for concentric extension at 240°/s was significantly higher in the JNT compared with the NT (p=0.04; d=1.02. However, the results of individual evaluation show that the BFD was more frequent in the NT in most measurements. A high BFD was evident in the eccentric mode in both groups highlighting a need for particular strengthening. With regard to low strength ratios a prevention programme should be suggested for both observed groups of professional female handball players to reduce the risk of injury.

  10. Training strategy of explosive strength in young female volleyball players.

    Science.gov (United States)

    Pereira, Ana; Costa, Aldo M; Santos, Patricia; Figueiredo, Teresa; João, Paulo Vicente

    2015-01-01

    The aim of this study was to examine the effect of an 8-week combined jump and ball throwing training program in the performance of upper and lower extremities among young female volleyball players of the high school. A total of 20 young female volleyball players playing at Scholar Sport in High School at the district level were divided in two groups: the experimental group (n=10; 14.0±0.0 years; 1.6±0.1 m; 52.0±7.0 kg and 20.7±2.4% body mass) and the control group (n=10; 13.8±0.4 years, 1.6±0.1 m; 53.5±4.7 kg and 20.3±1.7% body mass). The experimental group received additional plyometric and ball throwing exercises besides their normal volleyball practice. The control group underwent only their regular session of training. Strength performance in the experimental group significantly improved (medicine ball and volleyball ball throwing: P=0.00; and counter movement jump: P=0.05), with the improvement ranging from 5.3% to 20.1%. No significant changes in strength performance were observed in the control group (P>0.05). The 8-week combined jump and ball throwing training can significantly improve muscular performance in young female volleyball players. These findings may be useful for all physical education teachers and volleyball coaches. Copyright © 2015 Lithuanian University of Health Sciences. Production and hosting by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  11. Identification of the auditorium with successful tennis players

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    Dugalić Sretenka

    2015-01-01

    Full Text Available This paper presents the results of interviewing a sample of 229 respondents from Belgrade who are of a different gender, age and employment status. The study is a continuation of an earlier pilot study, with the help of identical questionnaires conducted through the Internet (Google form. The aim was to investigate the affinity of respondents concerning the business from which celebrities come, and to identify the similarities and differences in attitudes from which the promotional power of athletes may be evaluated. The study included a set of questions, some of which are presented in this paper: 1/ to what extent sport and sporting celebrities influence the decision of the respondents; 2/ assessing the similarity of equipment that respondents utilized if they play tennis (amateur, recreational or professional, with the equipment of their favorite players. During the answer to the second question, the respondents kept in mind certain players. The answers were analyzed by means of descriptive analysis. These studies show that a promotional power exists between the widest audiences of athletes. The study should encourage greater proficiency in the evaluation of sporting talent as scarce human resources, which, although burdened with costs, often remains unvalued, in terms of the declining nature of their athletic performance during their career. The research results show: 1 / respondents of different age and genders prefer sport as an activity from which celebrities come; 2 / 81.25% of those who play tennis identified using the brand of equipment as their favorite players, and the highest agreement in attitudes has been achieved with the variables of gender and employment. The study provides an answer to the question of which target group, within a promotional capacity, results in a conversion of sport results, and contributes to the strengthening of national identity through loyalty to proven sporting values.

  12. Isokinetic Strength Profile of Elite Female Handball Players.

    Science.gov (United States)

    Xaverova, Zuzana; Dirnberger, Johannes; Lehnert, Michal; Belka, Jan; Wagner, Herbert; Orechovska, Karolina

    2015-12-22

    Systematic assessment of muscle strength of the lower extremities throughout the annual training cycle in athletes is crucial from a performance perspective for the optimization of the training process, as well as a health perspective with regard to injury prevention. The main aim of the present study was to determine isokinetic muscle strength of the knee flexors and extensors in female handball players at the beginning of a preparatory period and to assess whether there were any differences between players of different performance levels. The performance level was expressed by means of membership of the Women's Junior National Handball Team (JNT, n=8) or the Women's National Handball Team (NT, n=9). The isokinetic peak torque during concentric and eccentric single-joint knee flexion and extension was measured at angular velocities of 60, 180, 240°/s (concentric) and 60°/s (eccentric). The Mann-Whitney test showed no significant differences in the peak torques or ipsilateral ratios between the two groups. The bilateral force deficit (BFD) for concentric extension at 240°/s was significantly higher in the JNT compared with the NT (p=0.04; d=1.02). However, the results of individual evaluation show that the BFD was more frequent in the NT in most measurements. A high BFD was evident in the eccentric mode in both groups highlighting a need for particular strengthening. With regard to low strength ratios a prevention programme should be suggested for both observed groups of professional female handball players to reduce the risk of injury.

  13. Radiographic findings of femoroacetabular impingement in capoeira players.

    Science.gov (United States)

    Mariconda, Massimo; Cozzolino, Andrea; Di Pietto, Francesco; Ribas, Manuel; Bellotti, Vittorio; Soldati, Alessandra

    2014-04-01

    Capoeira is a Brazilian martial art that requires extreme movements of the hip to perform jumps and kicks. This study evaluated a group of capoeira players to assess the prevalence of femoroacetabular impingement (FAI) in athletes practicing this martial art. Twenty-four experienced capoeira players (14 men, 10 women) underwent a diagnostic assessment, including clinical examination and standard radiographs of the pelvis and hips. The α-angle, head-neck offset, crossover sign, acetabular index, lateral centre-edge angle, and the Tönnis grade were assessed using the radiographs. Clinical relationships for any radiographic abnormalities indicating FAI were also evaluated. Four subjects (17 %) reported pain in their hips. Forty-four hips (91.7 %) had at least one radiographic sign of CAM impingement, and 22 (45.8 %) had an α-angle of more than 60°. Eighteen hips (37.5 %) had at least one sign of pincer impingement and 16 (33.3 %) a positive crossover sign. Sixteen hips (33.3 %) had mixed impingement. There was a significant positive association between having an α-angle of more than 60° and the presence of groin pain (P = 0.002). A reduced femoral head-neck offset (P < 0.001) and an increased α-angle on the anteroposterior radiograph (P = 0.008) were independently associated with a higher Tönnis grade. High prevalence of radiographic CAM-type FAI among these skilled capoeira players was found. In these subjects, a negative clinical correlation for an increased α-angle was also detected. Additional caution should be exercised whenever subjects with past or present hip pain engage in capoeira.

  14. Variability of aerobic abilities of football players during competition season

    Directory of Open Access Journals (Sweden)

    Novaković P.

    2012-01-01

    Full Text Available The purpose of this study is to determine whether there are differences in VO2max during one season in a team of semi-professional football players. This study will also determine the differences between groups, in relation to their position in the team, as well as in relation between the first team and the reserves. This study was conducted on a male football team, between 16 and 28 years of age and with no health problems, competing in a third-tier league. The technique employed is testing and the instrument is the Shuttle Run test that estimated their aerobic capacity. The testing was conducted indirectly during field tests at the beginning of the preparatory period, at the beginning of the competing period and at the end of the season. After a statistical analysis, it can be concluded that there are significant differences between the initial testing, control testing, and final testing. The initial testing was done at the beginning of the preparatory period and the results of the test ranged from 41.50 to 58.10 ml/kg/min. Then after six weeks, which was also right before the start of the competitive part of the season, the control testing was conducted and the results ranged from 46.90 to 62.30 ml/kg/min. Finally, at the end of the season, after all league matches had been played, the final testing was carried out and the results were obtained ranging from 43.80 to 62.00 ml/kg/min. All the testing was conducted on a sample of 31 players, where no relation was discovered between the status of the players at any of the three time points. However, there were some statistically significant differences from the aspect of the players' position but that is due to the goalkeepers being statistically different from the rest of the team. The cause of the differences in the obtained results are differences in intensity, volume and type of training depending on the stage of the season, as well as the specificity of training for the various positions in

  15. Short Duration Heat Acclimation in Australian Football Players

    Science.gov (United States)

    Kelly, Monica; Gastin, Paul B.; Dwyer, Daniel B; Sostaric, Simon; Snow, Rodney J.

    2016-01-01

    This study examined if five sessions of short duration (27 min), high intensity, interval training (HIIT) in the heat over a nine day period would induce heat acclimation in Australian football (AF) players. Fourteen professional AF players were matched for VO2peak (mL·kg-1·min-1) and randomly allocated into either a heat acclimation (Acc) (n = 7) or Control (Con) group (n = 7). The Acc completed five cycle ergometer HIIT sessions within a nine day period on a cycle ergometer in the heat (38.7 ± 0.5 °C; 34.4 ± 1.3 % RH), whereas Con trained in thermo-neutral conditions (22.3 ± 0.2 °C; 35.8 ± 0. % RH). Four days prior and two days post HIIT participants undertook a 30 min constant load cycling test at 60% V̇O2peak in the heat (37.9 ± 0.1 °C; 28.5 ± 0.7 % RH) during which VO2, blood lactate concentration ([Lac-]), heart rate (HR), rating of perceived exertion (RPE), thermal comfort, core and skin temperatures were measured. Heat acclimation resulted in reduced RPE, thermal comfort and [Lac-] (all p HIIT, in both groups. Heat acclimation did not influence any other measured variables. In conclusion, five short duration HIIT sessions in hot dry conditions induced limited heat acclimation responses in AF players during the in-season competition phase. In practice, the heat acclimation protocol can be implemented in a professional team environment; however the physiological adaptations resulting from such a protocol were limited. Key points Some minor heat acclimation adaptations can be induced in professional AF players with five 27 min non-consecutive, short duration HIIT sessions in the heat. The heat acclimation protocol employed in this study was able to be implemented in a professional team sport environment during an actual competitive season. Elevating and maintaining a high core temperature sufficient for heat acclimation likely requires a longer heat training session or some pre-heating prior to exercise. PMID:26957934

  16. Clinical Measures of Shoulder Mobility in the Professional Baseball Player.

    Science.gov (United States)

    Downar, Jacquelyn M; Sauers, Eric L

    2005-03-01

    Context: Professional baseball players must achieve a delicate balance between shoulder mobility and stability to attain optimal sports performance. The sport-specific demands of repetitive overhead throwing may result in an altered mobility-stability relationship.Objective: To evaluate clinical measures of shoulder mobility in professional baseball players in order to examine differences between the throwing and the nonthrowing shoulders and to describe chronic adaptations to throwing.Design: Descriptive.Setting: The athletic training room at Maryvale Baseball Park, Phoenix, AZ.Patients or Other Participants: Twenty-seven professional baseball players (20 pitchers, 7 position players; age = 20 +/- 1.6 years, height = 190.5 +/- 4.8 cm, mass = 91.6 +/- 9.6 kg) with no previous history of shoulder or elbow injury.Main Outcome Measure(s): We recorded scapular upward rotation at 4 levels of humeral elevation in the scapular plane (rest, 60 degrees , 90 degrees , 120 degrees ); posterior shoulder tightness; and passive, isolated glenohumeral joint internal and external range of motion.Results: Scapular upward rotation was significantly greater in the throwing shoulder (14.2 +/- 6.5 degrees ) than in the nonthrowing shoulder (10.6 +/- 6.1 degrees ) at 90 degrees of humeral elevation (P = .04). We observed no statistically significant difference in posterior shoulder tightness between the throwing (30.2 +/- 4.6 cm) and the nonthrowing (28.0 +/- 4.8 cm) shoulder (P = .09). In addition, the throwing shoulder exhibited a statistically significant decrease in isolated glenohumeral internal rotation (56.6 +/- 12.5 degrees ) compared with the nonthrowing shoulder (68.6 +/- 12.6 degrees ) (P = .001), with a concomitant increase in isolated glenohumeral external rotation (throwing = 108.9 +/- 9.0 degrees , nonthrowing = 101.9 +/- 5.9 degrees , P = .0014). An analysis of the total arc of motion (internal rotation + external rotation) revealed no statistically significant

  17. Meet the players: local translation at the synapse

    Directory of Open Access Journals (Sweden)

    Sandra eFernandez Moya

    2014-11-01

    Full Text Available It is widely believed that activity-dependent synaptic plasticity is the basis for learning and memory. Both processes are dependent on new protein synthesis at the synapse. Here, we describe a mechanism how dendritic mRNAs are transported and subsequently translated at activated synapses. Furthermore, we present the players involved in the regulation of local dendritic translation upon neuronal stimulation and their molecular interplay that maintain local proteome homeostasis. Any dysregulation causes several types of neurological disorders including muscular atrophies, cancers, neuropathies, neurodegenerative and cognitive disorders.

  18. Analysis of Dehydration and Strength in Elite Badminton Players

    Science.gov (United States)

    Abián-Vicén, Javier; Del Coso, Juan; González-Millán, Cristina; Salinero, Juan José; Abián, Pablo

    2012-01-01

    Background The negative effects of dehydration on aerobic activities are well established. However, it is unknown how dehydration affects intermittent sports performance. The purpose of this study was to identify the level of dehydration in elite badminton players and its relation to muscle strength and power production. Methodology Seventy matches from the National Spanish badminton championship were analyzed (46 men’s singles and 24 women’s singles). Before and after each match, jump height and power production were determined during a countermovement jump on a force platform. Participants’ body weight and a urine sample were also obtained before and after each match. The amount of liquid that the players drank during the match was also calculated by weighing their individual drinking bottles. Results and Discussion Sweat rate during the game was 1.14±0.46 l/h in men and 1.02±0.64 l/h in women. The players rehydrated at a rate of 1.10±0.55 l/h and 1.01±0.44 l/h in the male and female groups respectively. Thus, the dehydration attained during the game was only 0.37±0.50% in men and 0.32±0.83% in women. No differences were found in any of the parameters analyzed during the vertical jump (men: from 31.82±5.29 to 32.90±4.49 W/kg; p>0.05, women: from 26.36±4.73 to 27.25±4.44 W/kg; p>0.05). Post-exercise urine samples revealed proteinuria (60.9% of cases in men and 66.7% in women), leukocyturia (men = 43.5% and women = 50.0%) and erythrocyturia (men = 50.0% and women = 21.7%). Conclusions Despite a moderate sweat rate, badminton players adequately hydrated during a game and thus the dehydration attained was low. The badminton match did not cause muscle fatigue but it significantly increased the prevalence of proteinuria, leukocyturia and erythrocyturia. PMID:22666396

  19. Procedural Personas for Player Decision Modeling and Procedural Content Generation

    DEFF Research Database (Denmark)

    Holmgård, Christoffer

    2016-01-01

    in specific games. It further explores how simple utility functions, easily defined and changed by game designers, can be used to construct agents expressing a variety of decision making styles within a game, using a variety of contemporary AI approaches, naming the resulting agents "Procedural Personas......." These methods for constructing procedural personas are then integrated with existing procedural content generation systems, acting as critics that shape the output of these systems, optimizing generated content for different personas and by extension, different kinds of players and their decision making styles...

  20. Online Game Player Personality and Real-life Need Fulfillment

    Directory of Open Access Journals (Sweden)

    Ching-I Teng

    2009-12-01

    Full Text Available This study investigates the relationship between personality and real-life need fulfillment of 114 online game adolescent players, who had an average of 14.86 years in age and a standard deviation of 1.40 years. Of the sample, 73.7% were male and 88.8% had a monthly income below US $90. Results indicate that openness negatively correlated to fulfillment of needs for achievement and affiliation. Conscientiousness positively correlated to fulfillment of needs for achievement, affiliation, autonomy, and dominance. Extraversion positively correlated to fulfillment of needs for affiliation and dominance.