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

PubMed

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.

Prospective Player-Reported Injuries in Female Youth Fast-Pitch Softball Players.

PubMed

Smith, Matthew V; Davis, Randi; Brophy, Robert H; Prather, Heidi; Garbutt, Jane; Wright, Rick W

2015-01-01

There is a scarcity of literature evaluating injuries in youth fast-pitch softball players. To perform a descriptive analysis of player-reported injuries in youth fast-pitch softball position players and pitchers during a single select-level season. Prospective observation cohort study. Level 3. Ninety-eight athletes (48 pitchers, 50 position players) were followed for a single select fast-pitch softball season. Study participants completed web-based surveys every 3 weeks reporting injuries related to participation in fast-pitch softball. Injury was defined as pain causing cessation of participation in the current game or practice that prevents the player's return to that session or any pain that causes cessation of a player's customary participation on the day after the day of onset. The median age of the study participants was 14 years (range, 9-18 years). There were 49 reported injuries in 98 athletes. The average age was 13 years for those not injured and 14 years for those who were injured (P < 0.02). There were 31 injuries that were not related to pitching: 19 occurred in position players and 12 occurred in pitchers; 70% of these injuries were to the lower extremity. The proportion of injuries not related to pitching was significantly greater than the proportion of injuries related to pitching (P < 0.02). Eighteen injuries among the 48 pitchers (38%) were directly attributed to pitching. Among the 18 pitching injuries, 11 (61%) involved the shoulder. The majority (78%) of injuries related to pitching occurred in the first 6 weeks of the season. There was a high incidence of injury in this prospective cohort of youth select-level fast-pitch softball players. Better off-season and preseason conditioning may be a key factor for reducing pitching injuries. Recognition of injury patterns in fast-pitch softball players is critical to developing strategies to keep these athletes competing safely. © 2015 The Author(s).

Dynamics of tactical behaviour in association football when manipulating players' space of interaction.

PubMed

Ric, Angel; Torrents, Carlota; Gonçalves, Bruno; Torres-Ronda, Lorena; Sampaio, Jaime; Hristovski, Robert

2017-01-01

highly unstable when the distance from the target decreased. Ball location relative to the scoring zone and interpersonal distance constitute key environmental information that constrains the players' coordinative behaviour. Based on our results, dynamic overlap is presented as a good option to capture tactical performance. Moreover, the selected collective (i.e. relational) variables would allow coaches to identify the effects of training drills on teams and players' behaviour. More research is needed considering these type variables to understand how the manipulation of constraints induce a more stable or flexible dynamical structure of tactical behaviour.

A prospective cohort study identifying risk factors for shoulder injuries in adolescent elite handball players: the Karolinska Handball Study (KHAST) study protocol.

PubMed

Asker, Martin; Waldén, Markus; Källberg, Henrik; Holm, Lena W; Skillgate, Eva

2017-11-22

Handball is a physical contact sport that includes frequent overhead throwing, and this combination leads to a high rate of shoulder injuries. Several factors have been associated with shoulder injuries in overhead athletes, but strong scientific evidence is lacking for most suggested risk factors. We therefore designed the Karolinska Handball Study (KHAST) with the aim to identify risk factors for shoulder injuries in adolescent male and female elite handball players studying at handball-profiled secondary schools in Sweden. Secondary objectives are to investigate whether shoulder function changes during the competition season and whether the physical profile of the players changes during their time in secondary school. Players aged 15 to 19 years were included during the pre-season period of the 2014-2015 and the 2015-2016 seasons. At inclusion, players signed informed consent and filled in a questionnaire regarding playing position, playing level, previous handball experience, history of shoulder problems and athletic identity. Players also completed a detailed test battery at baseline evaluating the shoulder, neck and trunk. Players were then prospectively monitored weekly during the 2014-2015 and/or 2015-2016 competitive seasons regarding injuries and training/match workload. Results from the annual routine physical tests in the secondary school curriculum including bench press, deep squat, hand grip strength, clean lifts, squat jumps, counter movement jumps, <30 m sprints, chins, dips and Cooper's test will be collected until the end of the competitive season 2017-2018. The primary outcome is the incidence of shoulder injuries and shoulder problems. The secondary outcome is the prevalence of shoulder injuries and shoulder problems. Shoulder problems are frequent among handball players and a reduction of these injuries is therefore warranted. However, in order to introduce appropriate preventive measures, a detailed understanding of the underlying risk

Exploring Game Performance in the National Basketball Association Using Player Tracking Data

PubMed Central

Calleja-González, Julio; Jiménez Sáiz, Sergio; Schelling i del Alcázar, Xavi; Balciunas, Mindaugas

2015-01-01

Recent player tracking technology provides new information about basketball game performance. The aim of this study was to (i) compare the game performances of all-star and non all-star basketball players from the National Basketball Association (NBA), and (ii) describe the different basketball game performance profiles based on the different game roles. Archival data were obtained from all 2013-2014 regular season games (n = 1230). The variables analyzed included the points per game, minutes played and the game actions recorded by the player tracking system. To accomplish the first aim, the performance per minute of play was analyzed using a descriptive discriminant analysis to identify which variables best predict the all-star and non all-star playing categories. The all-star players showed slower velocities in defense and performed better in elbow touches, defensive rebounds, close touches, close points and pull-up points, possibly due to optimized attention processes that are key for perceiving the required appropriate environmental information. The second aim was addressed using a k-means cluster analysis, with the aim of creating maximal different performance profile groupings. Afterwards, a descriptive discriminant analysis identified which variables best predict the different playing clusters. The results identified different playing profile of performers, particularly related to the game roles of scoring, passing, defensive and all-round game behavior. Coaching staffs may apply this information to different players, while accounting for individual differences and functional variability, to optimize practice planning and, consequently, the game performances of individuals and teams. PMID:26171606

Exploring Game Performance in the National Basketball Association Using Player Tracking Data.

PubMed

Sampaio, Jaime; McGarry, Tim; Calleja-González, Julio; Jiménez Sáiz, Sergio; Schelling I Del Alcázar, Xavi; Balciunas, Mindaugas

2015-01-01

Recent player tracking technology provides new information about basketball game performance. The aim of this study was to (i) compare the game performances of all-star and non all-star basketball players from the National Basketball Association (NBA), and (ii) describe the different basketball game performance profiles based on the different game roles. Archival data were obtained from all 2013-2014 regular season games (n = 1230). The variables analyzed included the points per game, minutes played and the game actions recorded by the player tracking system. To accomplish the first aim, the performance per minute of play was analyzed using a descriptive discriminant analysis to identify which variables best predict the all-star and non all-star playing categories. The all-star players showed slower velocities in defense and performed better in elbow touches, defensive rebounds, close touches, close points and pull-up points, possibly due to optimized attention processes that are key for perceiving the required appropriate environmental information. The second aim was addressed using a k-means cluster analysis, with the aim of creating maximal different performance profile groupings. Afterwards, a descriptive discriminant analysis identified which variables best predict the different playing clusters. The results identified different playing profile of performers, particularly related to the game roles of scoring, passing, defensive and all-round game behavior. Coaching staffs may apply this information to different players, while accounting for individual differences and functional variability, to optimize practice planning and, consequently, the game performances of individuals and teams.

Use of the RSA/RCOD Index to Identify Training Priority in Soccer Players.

PubMed

Wong, Del P; Hjelde, Geir H; Cheng, Ching-Feng; Ngo, Jake K

2015-10-01

The use of RSA/RCOD index indicates the repeated change-of-direction (RCOD) performance relative to the repeated-sprint ability (RSA) and provides a standardized approach to prioritize training needs for RSA and RCOD. To compare the RSA/RCOD index among different age groups, RSA and RCOD were measured from 20 under-16 players (U16), 20 under-19 players (U19), and 17 first-team professional players (PRO) from a football (soccer) club that has regular participation in the UEFA Champions League. Each player performed the RSA and RCOD tests, during which the fastest time (FT), average time (AT), total time (TT), and percentage decrement score (%Dec) were recorded. No significant differences were found in RSA/RCOD index-FT, AT, TT, and %Dec among the 3 groups (p > 0.05) and between U19 and PRO in all RSA and RCOD measures (p > 0.05). Most values of RSA/RCOD index were 0.51 among the U16, U19, and PRO groups. Moreover, we concluded that the RSA/RCOD index might not be further changed after 16 years of age unless specific training programs for RSA and RCOD are prescribed. Therefore, this study provides an empirical case, and coaches can establish the RSA/RCOD index value relevant to their training system and monitor players' training needs of RSA and RCOD in a longer term.

Dynamics of tactical behaviour in association football when manipulating players' space of interaction

PubMed Central

Torrents, Carlota; Gonçalves, Bruno; Torres-Ronda, Lorena; Sampaio, Jaime; Hristovski, Robert

2017-01-01

The analysis of positional data in association football allows the spatial distribution of players during matches to be described in order to improve the understanding of tactical-related constraints on the behavioural dynamics of players. The aim of this study was to identify how players’ spatial restrictions affected the exploratory tactical behaviour and constrained the perceptual-motor workspace of players in possession of the ball, as well as inter-player passing interactions. Nineteen professional outfield male players were divided into two teams of 10 and 9 players, respectively. The game was played under three spatial constraints: a) players were not allowed to move out of their allocated zones, except for the player in possession of the ball; b) players were allowed to move to an adjacent zone, and; c) non-specific spatial constraints. Positional data was captured using a 5 Hz interpolated GPS tracking system and used to define the configuration states of players for each second in time. The configuration state comprised 37 categories derived from tactical actions, distance from the nearest opponent, distance from the target and movement speed. Notational analysis of players in possession of the ball allowed the mean time of ball possession and the probabilities of passing the ball between players to be calculated. The results revealed that the players’ long-term exploratory behaviour decreased and their short-term exploration increased when restricting their space of interaction. Relaxing players’ positional constraints seemed to increase the speed of ball flow dynamics. Allowing players to move to an adjacent sub-area increased the probabilities of interaction with the full-back during play build-up. The instability of the coordinative state defined by being free from opponents when players had the ball possession was an invariant feature under all three task constraints. By allowing players to move to adjacent sub-areas, the coordinative state

Identifying factors perceived to influence the development of elite youth football academy players.

PubMed

Mills, Andrew; Butt, Joanne; Maynard, Ian; Harwood, Chris

2012-01-01

Based on the developmental theory presented by Gagné (2009), we examined the factors perceived to influence the development of elite youth football players at a critical stage in their progression to the professional level. Transcribed interviews with ten expert development coaches were inductively and deductively content analysed. Conceptualisation of the data revealed six interrelated higher-order categories that represented the factors perceived to either positively or negatively influence player development. These were: awareness (e.g. self-awareness, awareness of others); resilience (e.g. coping with setbacks, optimistic attitude); goal-directed attributes (e.g. passion, professional attitude); intelligence (e.g. sport intelligence, emotional competence); sport-specific attributes (e.g. coachability, competitiveness); and environmental factors (e.g. significant others, culture of game). In this investigation, awareness emerged as a fundamental and mediating element for understanding how young players are able to transition to the professional level. Collectively, the findings underline the multidimensional nature of talent development and suggest that an intricate combination of stage-specific factors must manifest for gifted young players to translate their potential into excellence. Mechanisms by which academies could be helped to shape the characteristics and conditions associated with effective development are discussed.

A free-access online key to identify Amazonian ferns.

PubMed

Zuquim, Gabriela; Tuomisto, Hanna; Prado, Jefferson

2017-01-01

There is urgent need for more data on species distributions in order to improve conservation planning. A crucial but challenging aspect of producing high-quality data is the correct identification of organisms. Traditional printed floras and dichotomous keys are difficult to use for someone not familiar with the technical jargon. In poorly known areas, such as Amazonia, they also become quickly outdated as new species are described or ranges extended. Recently, online tools have allowed developing dynamic, interactive, and accessible keys that make species identification possible for a broader public. In order to facilitate identifying plants collected in field inventories, we developed an internet-based free-access tool to identify Amazonian fern species. We focused on ferns, because they are easy to collect and their edaphic affinities are relatively well known, so they can be used as an indicator group for habitat mapping. Our key includes 302 terrestrial and aquatic entities mainly from lowland Amazonian forests. It is a free-access key, so the user can freely choose which morphological features to use and in which order to assess them. All taxa are richly illustrated, so specimens can be identified by a combination of character choices, visual comparison, and written descriptions. The identification tool was developed in Lucid 3.5 software and it is available at http://keyserver.lucidcentral.org:8080/sandbox/keys.jsp.

A free-access online key to identify Amazonian ferns

PubMed Central

Zuquim, Gabriela; Tuomisto, Hanna; Prado, Jefferson

2017-01-01

Abstract There is urgent need for more data on species distributions in order to improve conservation planning. A crucial but challenging aspect of producing high-quality data is the correct identification of organisms. Traditional printed floras and dichotomous keys are difficult to use for someone not familiar with the technical jargon. In poorly known areas, such as Amazonia, they also become quickly outdated as new species are described or ranges extended. Recently, online tools have allowed developing dynamic, interactive, and accessible keys that make species identification possible for a broader public. In order to facilitate identifying plants collected in field inventories, we developed an internet-based free-access tool to identify Amazonian fern species. We focused on ferns, because they are easy to collect and their edaphic affinities are relatively well known, so they can be used as an indicator group for habitat mapping. Our key includes 302 terrestrial and aquatic entities mainly from lowland Amazonian forests. It is a free-access key, so the user can freely choose which morphological features to use and in which order to assess them. All taxa are richly illustrated, so specimens can be identified by a combination of character choices, visual comparison, and written descriptions. The identification tool was developed in Lucid 3.5 software and it is available at http://keyserver.lucidcentral.org:8080/sandbox/keys.jsp. PMID:28781548

Prospective Player-Reported Injuries in Female Youth Fast-Pitch Softball Players

PubMed Central

Smith, Matthew V.; Davis, Randi; Brophy, Robert H.; Prather, Heidi; Garbutt, Jane; Wright, Rick W.

2015-01-01

Background: There is a scarcity of literature evaluating injuries in youth fast-pitch softball players. Purpose: To perform a descriptive analysis of player-reported injuries in youth fast-pitch softball position players and pitchers during a single select-level season. Study Design: Prospective observation cohort study. Level of Evidence: Level 3. Methods: Ninety-eight athletes (48 pitchers, 50 position players) were followed for a single select fast-pitch softball season. Study participants completed web-based surveys every 3 weeks reporting injuries related to participation in fast-pitch softball. Injury was defined as pain causing cessation of participation in the current game or practice that prevents the player’s return to that session or any pain that causes cessation of a player’s customary participation on the day after the day of onset. Results: The median age of the study participants was 14 years (range, 9-18 years). There were 49 reported injuries in 98 athletes. The average age was 13 years for those not injured and 14 years for those who were injured (P < 0.02). There were 31 injuries that were not related to pitching: 19 occurred in position players and 12 occurred in pitchers; 70% of these injuries were to the lower extremity. The proportion of injuries not related to pitching was significantly greater than the proportion of injuries related to pitching (P < 0.02). Eighteen injuries among the 48 pitchers (38%) were directly attributed to pitching. Among the 18 pitching injuries, 11 (61%) involved the shoulder. The majority (78%) of injuries related to pitching occurred in the first 6 weeks of the season. Conclusion: There was a high incidence of injury in this prospective cohort of youth select-level fast-pitch softball players. Better off-season and preseason conditioning may be a key factor for reducing pitching injuries. Clinical Relevance: Recognition of injury patterns in fast-pitch softball players is critical to developing strategies to

EphA2 receptor is a key player in the metastatic onset of Ewing sarcoma.

PubMed

Garcia-Monclús, Silvia; López-Alemany, Roser; Almacellas-Rabaiget, Olga; Herrero-Martín, David; Huertas-Martinez, Juan; Lagares-Tena, Laura; Alba-Pavón, Piedad; Hontecillas-Prieto, Lourdes; Mora, Jaume; de Álava, Enrique; Rello-Varona, Santi; Giangrande, Paloma H; Tirado, Oscar M

2018-03-26

Ewing sarcoma (ES) is the second most common bone malignancy affecting children and young adults with poor prognosis due to high metastasis incidence. Our group previously described that EphA2, a tyrosine kinase receptor, promotes angiogenesis in Ewing sarcoma (ES) cells via ligand-dependent signaling. Now we wanted to explore EphA2 ligand-independent activity, controlled upon phosphorylation at S897 (p-EphA2 S897 ), as it has been linked to metastasis in several malignancies. By reverse genetic engineering we explored the phenotypic changes after EphA2 removal or reintroduction. Gene expression microarray was used to identify key players in EphA2 signaling. Mice were employed to reproduce metastatic processes from orthotopically implanted engineered cells. We established a correlation between ES cells aggressiveness and p-EphA2 S897 . Moreover, stable overexpression of EphA2 in low EphA2 expression ES cells enhanced proliferation and migration, but not a non-phosphorylable mutant (S987A). Consistently, silencing of EphA2 reduced tumorigenicity, migration and invasion in vitro, and lung metastasis incidence in experimental and spontaneous metastasis assays in vivo. A gene expression microarray revealed the implication of EphA2 in cell signaling, cellular movement and survival. ADAM19 knockdown by siRNA technology strongly reproduced the negative effects on cell migration observed after EphA2 silencing. Altogether, our results suggest that p-EphA2 S897 correlates with aggressiveness in ES, so blocking its function may be a promising treatment. © 2018 UICC.

Nutritional guidance to soccer players for training and competition.

PubMed

Clark, K

1994-01-01

Strategies for a nutrition education as applied to individual soccer players provide a key to guiding them towards appropriate food selection. Scientific investigations have associated energy requirements, composition of the diet and carbohydrate intake with muscle glycogen storage, and adequacy of fluids with optimal athletic performance. In general, soccer players appear to consume adequate energy but low carbohydrate diets. The training diet should be comprised of 55-65% carbohydrate, 12-15% protein and less than 30% fat. The goal of the training diet is to provide adequate energy for weight maintenance, and 7-10 g of carbohydrate per kg body weight for maximizing glycogen storage. Nutritional needs for competition include eating prior to and after matches. Consumption of carbohydrate-rich foods for energy needs and glycogen resynthesis are key behaviours soccer players need to focus on daily. Qualified dietitians should be on hand to provide personal nutrition counselling, carbohydrate resource lists and education on food labels as simple and quick nutrition education strategies to guide soccer players, their parents, coaches and trainers towards improved food selections.

Discriminating talent-identified junior Australian football players using a video decision-making task.

PubMed

Woods, Carl T; Raynor, Annette J; Bruce, Lyndell; McDonald, Zane

2016-01-01

This study examined if a video decision-making task could discriminate talent-identified junior Australian football players from their non-talent-identified counterparts. Participants were recruited from the 2013 under 18 (U18) West Australian Football League competition and classified into two groups: talent-identified (State U18 Academy representatives; n = 25; 17.8 ± 0.5 years) and non-talent-identified (non-State U18 Academy selection; n = 25; 17.3 ± 0.6 years). Participants completed a video decision-making task consisting of 26 clips sourced from the Australian Football League game-day footage, recording responses on a sheet provided. A score of "1" was given for correct and "0" for incorrect responses, with the participants total score used as the criterion value. One-way analysis of variance tested the main effect of "status" on the task criterion, whilst a bootstrapped receiver operating characteristic (ROC) curve assessed the discriminant ability of the task. An area under the curve (AUC) of 1 (100%) represented perfect discrimination. Between-group differences were evident (P < 0.05) and the ROC curve was maximised with a score of 15.5/26 (60%) (AUC = 89.0%), correctly classifying 92% and 76% of the talent-identified and non-talent-identified participants, respectively. Future research should investigate the mechanisms leading to the superior decision-making observed in the talent-identified group.

Lipoproteins of Gram-Positive Bacteria: Key Players in the Immune Response and Virulence

PubMed Central

Nguyen, Minh Thu

2016-01-01

SUMMARY Since the discovery in 1973 of the first of the bacterial lipoproteins (Lpp) in Escherichia coli, Braun's lipoprotein, the ever-increasing number of publications indicates the importance of these proteins. Bacterial Lpp belong to the class of lipid-anchored proteins that in Gram-negative bacteria are anchored in both the cytoplasmic and outer membranes and in Gram-positive bacteria are anchored only in the cytoplasmic membrane. In contrast to the case for Gram-negative bacteria, in Gram-positive bacteria lipoprotein maturation and processing are not vital. Physiologically, Lpp play an important role in nutrient and ion acquisition, allowing particularly pathogenic species to better survive in the host. Bacterial Lpp are recognized by Toll-like receptor 2 (TLR2) of the innate immune system. The important role of Lpp in Gram-positive bacteria, particularly in the phylum Firmicutes, as key players in the immune response and pathogenicity has emerged only in recent years. In this review, we address the role of Lpp in signaling and modulating the immune response, in inflammation, and in pathogenicity. We also address the potential of Lpp as promising vaccine candidates. PMID:27512100

Are poker players all the same? Latent class analysis.

PubMed

Dufour, Magali; Brunelle, Natacha; Roy, Élise

2015-06-01

Poker is the gambling game that is currently gaining the most in popularity. However, there is little information on poker players' characteristics and risk factors. Furthermore, the first studies described poker players, often recruited in universities, as an homogeneous group who played in only one of the modes (land based or on the Internet). This study aims to identify, through latent class analyses, poker player subgroups. A convenience sample of 258 adult poker players was recruited across Quebec during special events or through advertising in various media. Participants filled out a series of questionnaires (Canadian Problem Gambling Index, Beck Depression, Beck Anxiety, erroneous belief and alcohol/drug consumption). The latent class analysis suggests that there are three classes of poker players. Class I (recreational poker players) includes those who have the lowest probability of engaging intensively in different game modes. Participants in class II (Internet poker players) all play poker on the Internet. This class includes the highest proportion of players who consider themselves experts or professionals. They make a living in part or in whole from poker. Class III (multiform players) includes participants with the broadest variety of poker patterns. This group is complex: these players are positioned halfway between professional and recreational players. Results indicate that poker players are not an homogeneous group identified simply on the basis of the form of poker played. The specific characteristics associated with each subgroup points to vulnerabilities that could potentially be targeted for preventive interventions.

Player and Game Characteristics and Head Impacts in Female Youth Ice Hockey Players.

PubMed

Reed, Nick; Taha, Tim; Greenwald, Richard; Keightley, Michelle

2017-08-01

  Despite the growing popularity of ice hockey among female youth and interest in the biomechanics of head impacts in sport, the head impacts sustained by this population have yet to be characterized.   To describe the number of, biomechanical characteristics of, and exposure to head impacts of female youth ice hockey players during competition and to investigate the influences of player and game characteristics on head impacts.   Cohort study.   Twenty-seven female youth ice hockey players (mean age = 12.5 ± 0.52 years) wore instrumented ice hockey helmets during 66 ice hockey games over a 3-year period. Data specific to player, game, and biomechanical head impact characteristics were recorded. A multiple regression analysis identified factors most associated with head impacts of greater frequency and severity.   A total of 436 total head impacts were sustained during 6924 minutes of active ice hockey participation (0.9 ± 0.6 impacts per player per game; range, 0-2.1). A higher body mass index (BMI) significantly predicted a higher number of head impacts sustained per game (P = .008). Linear acceleration of head impacts was greater in older players and those who played the forward position, had a greater BMI, and spent more time on the ice (P = .008), whereas greater rotational acceleration was present in older players who had a greater BMI and played the forward position (P = .008). During tournament games, increased ice time predicted increased severity of head impacts (P = .03).   This study reveals for the first time that head impacts are occurring in female youth ice hockey players, albeit at a lower rate and severity than in male youth ice hockey players, despite the lack of intentional body checking.

Left-handed skeletally mature baseball players have smaller humeral retroversion in the throwing arm than right-handed players.

PubMed

Takenaga, Tetsuya; Goto, Hideyuki; Sugimoto, Katsumasa; Tsuchiya, Atsushi; Fukuyoshi, Masaki; Nakagawa, Hiroki; Nozaki, Masahiro; Takeuchi, Satoshi; Otsuka, Takanobu

2017-12-01

It is known that the humeral retroversion of baseball players is greater in the throwing arm than in the nonthrowing arm. An investigation measuring dry bone specimens also showed that the right humerus had greater retroversion than the left. Considering these facts, it was hypothesized that humeral retroversion would differ between right- and left-handed players. This study aimed to compare the bilateral humeral retroversion between right- and left-handed skeletally mature baseball players. We investigated 260 (196 right-handed and 64 left-handed) male baseball players who belonged to a college or amateur team. Bilateral humeral retroversion was assessed using an ultrasound-assisted technique (humeral torsion angle [HTA]) as described by previous studies. Analysis of covariance, adjusted for handedness and baseball position, assessed the effect of throwing arm dominance on HTA. In comparison of the throwing arm, HTA was significantly smaller in left-handed (left humerus) than in right-handed (right humerus) players (77° vs. 81°; P < .001). In comparison of the nonthrowing arm, HTA was significantly greater in left-handed (right humerus) than in right-handed (left humerus) players (73° vs. 69°; P < .001). The mean side-to-side difference of HTA was significantly smaller in left-handed than in right-handed players (3° vs. 12°; P < .001). Humeral retroversion of left-handed skeletally mature baseball players was significantly smaller in the throwing arm, greater in the nonthrowing arm, and smaller in side-to-side differences than that of right-handed players. These findings may be key to understanding some of the biomechanical differences between right- and left-handed baseball players. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Phenylpropanoids are key players in the antioxidant defense to ozone of European ash, Fraxinus excelsior.

PubMed

Cotrozzi, Lorenzo; Campanella, Alessandra; Pellegrini, Elisa; Lorenzini, Giacomo; Nali, Cristina; Paoletti, Elena

2018-03-01

Physiological and biochemical responses to ozone (O 3 ) (150 ppb, 8 h day -1 , 35 consecutive days) of two Italian provenances (Piedmont and Tuscany) of Fraxinus excelsior L. were evaluated, with special attention to the role of phenylpropanoids. Our results indicate (i) the high O 3 sensitivity especially of Piedmont provenance (in terms of visible injury, water status, and photosynthetic apparatus); (ii) although the intra-specific sensitivity to O 3 between provenances differs (mainly due to different stomatal behaviors since only Tuscany plants partially avoided the uptake of the pollutant gas), both provenances showed detoxification and defense mechanisms; (iii) the crucial participation of phenylpropanoids, with a key role played by flavonoids (especially quercitrin): among this class of metabolites, isoquercitrin is the principal player in the lower O 3 sensitivity of Tuscany plants, together with lignins; (iv) although coumarins (typical compounds of Fraxinus) were severely depressed by O 3 , isofraxidin was triggered suggesting a key role in reactive oxygen species (ROS) detoxification, as well as trans-chalcone. Furthermore, the different behavior of verbascoside and oleuropein among provenances lead us to speculate on their influence in the tentatively repair or acclimation shown by Piedmont plants at the end of the exposure. Finally, the intra-specific O 3 sensitivity may be also due to de novo peaks triggered by O 3 not yet associated to some chemicals.

Comparative glycoproteomics of stem cells identifies new players in ricin toxicity.

PubMed

Stadlmann, Johannes; Taubenschmid, Jasmin; Wenzel, Daniel; Gattinger, Anna; Dürnberger, Gerhard; Dusberger, Frederico; Elling, Ulrich; Mach, Lukas; Mechtler, Karl; Penninger, Josef M

2017-09-28

Glycosylation, the covalent attachment of carbohydrate structures onto proteins, is the most abundant post-translational modification. Over 50% of human proteins are glycosylated, which alters their activities in diverse fundamental biological processes. Despite the importance of glycosylation in biology, the identification and functional validation of complex glycoproteins has remained largely unexplored. Here we develop a novel quantitative approach to identify intact glycopeptides from comparative proteomic data sets, allowing us not only to infer complex glycan structures but also to directly map them to sites within the associated proteins at the proteome scale. We apply this method to human and mouse embryonic stem cells to illuminate the stem cell glycoproteome. This analysis nearly doubles the number of experimentally confirmed glycoproteins, identifies previously unknown glycosylation sites and multiple glycosylated stemness factors, and uncovers evolutionarily conserved as well as species-specific glycoproteins in embryonic stem cells. The specificity of our method is confirmed using sister stem cells carrying repairable mutations in enzymes required for fucosylation, Fut9 and Slc35c1. Ablation of fucosylation confers resistance to the bioweapon ricin, and we discover proteins that carry a fucosylation-dependent sugar code for ricin toxicity. Mutations disrupting a subset of these proteins render cells ricin resistant, revealing new players that orchestrate ricin toxicity. Our comparative glycoproteomics platform, SugarQb, enables genome-wide insights into protein glycosylation and glycan modifications in complex biological systems.

Examining Player Anger in World of Warcraft

NASA Astrophysics Data System (ADS)

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.

Australian Football League concussion guidelines: what do community players think?

PubMed

White, Peta E; Donaldson, Alex; Sullivan, S John; Newton, Joshua; Finch, Caroline F

2016-01-01

Preventing concussion in sport is a global challenge. To assess community-level adult male Australian Football players' views on following the Australian Football League's (AFL) concussion guidelines. 3 focus groups, each comprising 6 players from 1 regional league, were conducted until saturation of issues raised. Discussions followed a semistructured script and were audio-recorded and transcribed verbatim. Thematic analysis was conducted by 2 coders independently. Identified advantages of the guidelines included highlighting the seriousness of concussion; changing the culture around playing with concussion and shifting return-to-play decision responsibility from players to others. Disadvantages included players being removed from play unnecessarily; removal of players' rights to decide if they are fit to play and players changing their behaviours to avoid being removed from play. Identified facilitators to guideline use included local league enforcement; broad information dissemination and impartial medically trained staff to assess concussion. Identified barriers to guideline use included players' desire to play at all costs; external pressure that encouraged players to return to play prematurely; and inconvenience and cost. Players generally understand that the AFL concussion guidelines protect their long-term welfare. However, their desire to play at all costs and help their team win is a common barrier to reporting concussion and adhering to guidelines. Leagues should take a lead role by mandating and enforcing the use of the guidelines and educating coaches, game day medical providers and players. The return-to-play component of the guidelines is complex and needs further consideration in the context of community sport.

Anthropometry of World-Class Elite Handball Players According to the Playing Position: Reports From Men's Handball World Championship 2013.

PubMed

Ghobadi, Hamid; Rajabi, Hamid; Farzad, Babak; Bayati, Mahdi; Jeffreys, Ian

2013-12-18

Identifying the anthropometric measures of successful and less successful handball players may be helpful in developing a talent identification and development model, allowing for the determination of key physical capacities required for elite performance. The purpose of the study was to describe the anthropometric characteristics, including age, standing stature, body mass and body mass index (BMI) in handball players who participated in the 2013 Men's Handball World Championships. Secondly, the objective was to identify the possible differences in these parameters in terms of individual playing positions (goalkeeper, back, center back, wing, line player). Rosters with handball player's age, standing stature, and body mass were obtained from the International Handball Federation website. The research material included 409 handball players (24 teams). National teams were organized by their ranks and sub-grouped using their continents and playing positions. The results of the analyses of variance demonstrated significant differences in age (F=2.30; p=0.044; Partial ŋ2=0.028), standing stature (F=14.02; p=0.0001; Partial ŋ2=0.148), and body mass (F=5.88; p=0.0001; Partial ŋ2=0.068) among the groups (G1-G6). Players in G1 had the highest standing stature and body mass, while players in G6 had the lowest age and body mass values. The backs and line players were the tallest. In addition, the measurement of body mass showed that the line players had the highest body mass and BMI values. In conclusion, this study presented anthropometric data that differentiated levels of success in male handball teams playing in the 2013 world championships. This information should serve as a reference for the average standing stature, body mass, and BMI of handball players for particular positions at the professional level.

UGT74S1 is the key player in controlling secoisolariciresinol diglucoside (SDG) formation in flax.

PubMed

Fofana, Bourlaye; Ghose, Kaushik; McCallum, Jason; You, Frank M; Cloutier, Sylvie

2017-02-02

Flax lignan, commonly known as secoisolariciresinol (SECO) diglucoside (SDG), has recently been reported with health-promoting activities, including its positive impact in metabolic diseases. However, not much was reported on the biosynthesis of SDG and its monoglucoside (SMG) until lately. Flax UGT74S1 was recently reported to sequentially glucosylate SECO into SMG and SDG in vitro. However, whether this gene is the only UGT achieving SECO glucosylation in flax was not known. Flax genome-wide mining for UGTs was performed. Phylogenetic and gene duplication analyses, heterologous gene expression and enzyme assays were conducted to identify family members closely related to UGT74S1 and to establish their roles in SECO glucosylation. A total of 299 different UGTs were identified, of which 241 (81%) were duplicated. Flax UGTs diverged 2.4-153.6 MYA and 71% were found to be under purifying selection pressure. UGT74S1, a single copy gene located on chromosome 7, displayed no evidence of duplication and was deemed to be under positive selection pressure. The phylogenetic analysis identified four main clusters where cluster 4, which included UGT74S1, was the most diverse. The duplicated UGT74S4 and UGT74S3, located on chromosomes 8 and 14, respectively, were the most closely related to UGT74S1 and were differentially expressed in different tissues. Heterologous expression levels of UGT74S1, UGT74S4 and UGT74S3 proteins were similar but UGT74S4 and UGT74S3 glucosylation activity towards SECO was seven fold less than UGT74S1. In addition, they both failed to produce SDG, suggesting neofunctionalization following their divergence from UGT74S1. We showed that UGT74S1 is closely related to two duplicated genes, UGT74S4 and UGT74S3 which, unlike UGT74S1, failed to glucosylate SMG into SDG. The study suggests that UGT74S1 may be the key player in controlling SECO glucosylation into SDG in flax although its closely related genes may also contribute to a minor extent in supplying

PLAYERS' PERCEPTIONS OF HOME ADVANTAGE IN THE AUSTRALIAN RUGBY LEAGUE COMPETITION.

PubMed

Mcguckin, Teneale A; Sinclair, Wade H; Sealey, Rebecca M; Bowman, Paul W

2015-12-01

This study was designed to pilot a survey to explore players' perception of home advantage in a rugby league. Twenty-seven players from one team with an identified home advantage believed a home advantage existed as a result of their home crowd (52%), family and friends' support (41%), normal travel (45%) and sleeping arrangements (37%), home weather conditions (48%), and familiarity with playing amenities (37%). However, the players were less definite about influences while playing away from home. The current sample of players identified differing influences, highlighting individual variations in perceived determinants. Individual interviews or focus groups will be required for further exploration.

Exploring Team Passing Networks and Player Movement Dynamics in Youth Association Football

PubMed Central

Coutinho, Diogo; Santos, Sara; Lago-Penas, Carlos; Jiménez, Sergio; Sampaio, Jaime

2017-01-01

Understanding how youth football players base their game interactions may constitute a solid criterion for fine-tuning the training process and, ultimately, to achieve better individual and team performances during competition. The present study aims to explore how passing networks and positioning variables can be linked to the match outcome in youth elite association football. The participants included 44 male elite players from under-15 and under-17 age groups. A passing network approach within positioning-derived variables was computed to identify the contributions of individual players for the overall team behaviour outcome during a simulated match. Results suggested that lower team passing dependency for a given player (expressed by lower betweenness network centrality scores) and high intra-team well-connected passing relations (expressed by higher closeness network centrality scores) were related to better outcomes. The correlation between the dyads’ positioning regularity and the passing density showed a most likely higher correlation in under-15 (moderate effect), indicating a possible more dependence of the ball position rather than in the under-17 teams (small/unclear effects). Overall, this study emphasizes the potential of coupling notational analyses with spatial-temporal relations to produce a more functional and holistic understanding of teams’ sports performance. Also, the social network analysis allowed to reveal novel key determinants of collective performance. PMID:28141823

Hear today, gone tomorrow: an assessment of portable entertainment player use and hearing acuity in a community sample.

PubMed

Shah, Samit; Gopal, Bharat; Reis, Janet; Novak, Michael

2009-01-01

Noise-induced hearing loss (NIHL) is a common but preventable disability. The purpose of this study was to assess the understanding of NIHL in a community sample in the context of exposure to portable music players, including MP3 players, and personal hearing acuity as tested with the Welch Allyn Audioscope 3. A cross-sectional convenience sample of 94 adults (18 to 65 years old) at a university recreation center completed an analysis of personal use of portable digital music players (MP3 players), concerns about hearing loss, and a 3-dB-level hearing test at 4 levels of speech frequency in a low ambient noise setting. The majority of participants (85%) were concerned about hearing loss, willing to protect their hearing with lower volume (77%), had little measurable hearing loss but were exposed to longer and louder periods of noise than other national samples, and mistakenly felt that NIHL is a medically reversible condition. Many (40%) also wanted their family medicine physician to be more concerned about their hearing. Family medicine physicians are in a key position to provide basic information on the preventability and negative consequences of NIHL, as well as to identify and refer patients with identified hearing loss.

Anthropometry of World-Class Elite Handball Players According to the Playing Position: Reports From Men’s Handball World Championship 2013

PubMed Central

Ghobadi, Hamid; Rajabi, Hamid; Farzad, Babak; Bayati, Mahdi; Jeffreys, Ian

2013-01-01

Identifying the anthropometric measures of successful and less successful handball players may be helpful in developing a talent identification and development model, allowing for the determination of key physical capacities required for elite performance. The purpose of the study was to describe the anthropometric characteristics, including age, standing stature, body mass and body mass index (BMI) in handball players who participated in the 2013 Men’s Handball World Championships. Secondly, the objective was to identify the possible differences in these parameters in terms of individual playing positions (goalkeeper, back, center back, wing, line player). Rosters with handball player’s age, standing stature, and body mass were obtained from the International Handball Federation website. The research material included 409 handball players (24 teams). National teams were organized by their ranks and sub-grouped using their continents and playing positions. The results of the analyses of variance demonstrated significant differences in age (F=2.30; p=0.044; Partial ŋ2=0.028), standing stature (F=14.02; p=0.0001; Partial ŋ2=0.148), and body mass (F=5.88; p=0.0001; Partial ŋ2=0.068) among the groups (G1–G6). Players in G1 had the highest standing stature and body mass, while players in G6 had the lowest age and body mass values. The backs and line players were the tallest. In addition, the measurement of body mass showed that the line players had the highest body mass and BMI values. In conclusion, this study presented anthropometric data that differentiated levels of success in male handball teams playing in the 2013 world championships. This information should serve as a reference for the average standing stature, body mass, and BMI of handball players for particular positions at the professional level. PMID:24511357

Combined analysis of mRNA and miRNA identifies dehydration and salinity responsive key molecular players in citrus roots.

PubMed

Xie, Rangjin; Zhang, Jin; Ma, Yanyan; Pan, Xiaoting; Dong, Cuicui; Pang, Shaoping; He, Shaolan; Deng, Lie; Yi, Shilai; Zheng, Yongqiang; Lv, Qiang

2017-02-06

Citrus is one of the most economically important fruit crops around world. Drought and salinity stresses adversely affected its productivity and fruit quality. However, the genetic regulatory networks and signaling pathways involved in drought and salinity remain to be elucidated. With RNA-seq and sRNA-seq, an integrative analysis of miRNA and mRNA expression profiling and their regulatory networks were conducted using citrus roots subjected to dehydration and salt treatment. Differentially expressed (DE) mRNA and miRNA profiles were obtained according to fold change analysis and the relationships between miRNAs and target mRNAs were found to be coherent and incoherent in the regulatory networks. GO enrichment analysis revealed that some crucial biological processes related to signal transduction (e.g. 'MAPK cascade'), hormone-mediated signaling pathways (e.g. abscisic acid- activated signaling pathway'), reactive oxygen species (ROS) metabolic process (e.g. 'hydrogen peroxide catabolic process') and transcription factors (e.g., 'MYB, ZFP and bZIP') were involved in dehydration and/or salt treatment. The molecular players in response to dehydration and salt treatment were partially overlapping. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis further confirmed the results from RNA-seq and sRNA-seq analysis. This study provides new insights into the molecular mechanisms how citrus roots respond to dehydration and salt treatment.

Combined analysis of mRNA and miRNA identifies dehydration and salinity responsive key molecular players in citrus roots

PubMed Central

Xie, Rangjin; Zhang, Jin; Ma, Yanyan; Pan, Xiaoting; Dong, Cuicui; Pang, Shaoping; He, Shaolan; Deng, Lie; Yi, Shilai; Zheng, Yongqiang; Lv, Qiang

2017-01-01

Citrus is one of the most economically important fruit crops around world. Drought and salinity stresses adversely affected its productivity and fruit quality. However, the genetic regulatory networks and signaling pathways involved in drought and salinity remain to be elucidated. With RNA-seq and sRNA-seq, an integrative analysis of miRNA and mRNA expression profiling and their regulatory networks were conducted using citrus roots subjected to dehydration and salt treatment. Differentially expressed (DE) mRNA and miRNA profiles were obtained according to fold change analysis and the relationships between miRNAs and target mRNAs were found to be coherent and incoherent in the regulatory networks. GO enrichment analysis revealed that some crucial biological processes related to signal transduction (e.g. ‘MAPK cascade’), hormone-mediated signaling pathways (e.g. abscisic acid- activated signaling pathway’), reactive oxygen species (ROS) metabolic process (e.g. ‘hydrogen peroxide catabolic process’) and transcription factors (e.g., ‘MYB, ZFP and bZIP’) were involved in dehydration and/or salt treatment. The molecular players in response to dehydration and salt treatment were partially overlapping. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis further confirmed the results from RNA-seq and sRNA-seq analysis. This study provides new insights into the molecular mechanisms how citrus roots respond to dehydration and salt treatment. PMID:28165059

Crosstalk between telomere maintenance and radiation effects: A key player in the process of radiation-induced carcinogenesis

PubMed Central

Shim, Grace; Ricoul, Michelle; Hempel, William M.; Azzam, Edouard I.; Sabatier, Laure

2014-01-01

It is well established that ionizing radiation induces chromosomal damage, both following direct radiation exposure and via non-targeted (bystander) effects, activating DNA damage repair pathways, of which the proteins are closely linked to telomeric proteins and telomere maintenance. Long-term propagation of this radiation-induced chromosomal damage during cell proliferation results in chromosomal instability. Many studies have shown the link between radiation exposure and radiation-induced changes in oxidative stress and DNA damage repair in both targeted and non-targeted cells. However, the effect of these factors on telomeres, long established as guardians of the genome, still remains to be clarified. In this review, we will focus on what is known about how telomeres are affected by exposure to low- and high-LET ionizing radiation and during proliferation, and will discuss how telomeres may be a key player in the process of radiation-induced carcinogenesis. PMID:24486376

Quantum Two Player Game in Thermal Environment

PubMed Central

Dajka, Jerzy; Kłoda, Dawid; Łobejko, Marcin; Sładkowski, Jan

2015-01-01

A two-player quantum game is considered in the presence of thermal decoherence. It is shown how the thermal environment modeled in terms of rigorous Davies approach affects payoffs of the players. The conditions for either beneficial or pernicious effect of decoherence are identified. The general considerations are exemplified by the quantum version of Prisoner Dilemma. PMID:26322833

The audiological health of horn players.

PubMed

Wilson, Wayne J; O'Brien, Ian; Bradley, Andrew P

2013-01-01

Among orchestral musicians, horn players are one of the most at-risk groups for noise-induced hearing loss (NIHL). To investigate this group further, pure tone audiometry and a 14-item questionnaire were used to assess the hearing health, as well as attitudes and practices regarding hearing conservation, among 142 French horn players attending an international horn conference in Brisbane, Australia. Of this study's French horn players, 11.1% to 22.2%, and 17.7% to 32.9% of those aged ≤40 years, showed some form of hearing loss (corrected for age and gender) typical of NIHL, using conservative versus lenient criteria, respectively. Stepwise multiple regression analyses showed no obvious predictor of hearing loss in this study's participants. Of the 18% of participants who reported using hearing protection, 81% used this protection "sometimes" and 50% used generic, foam, or other inferior forms of protection. Continued efforts to better manage the hearing health of horn players is warranted particularly as any hearing loss will affect a horn player's ability to perform and therefore his or her livelihood. Managing the hearing health of horn players will be challenging, however, with no simple predictor of NIHL loss being identified in this study's sample.

Efficiently detecting outlying behavior in video-game players.

PubMed

Kim, Young Bin; Kang, Shin Jin; Lee, Sang Hyeok; Jung, Jang Young; Kam, Hyeong Ryeol; Lee, Jung; Kim, Young Sun; Lee, Joonsoo; Kim, Chang Hun

2015-01-01

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.

Supporting Educational Success for Aboriginal Students: Identifying Key Influences

ERIC Educational Resources Information Center

Whitley, Jessica

2014-01-01

The academic difficulties experienced by many Aboriginal (First Nations, Métis, Inuit) students in Canada have been well-documented. Indicators such as school persistence and post-secondary enrollment are typically far lower for Aboriginal students as a group compared to non-Aboriginal students. Identifying facilitators of success is key to…

Australian Football League concussion guidelines: what do community players think?

PubMed Central

White, Peta E; Donaldson, Alex; Sullivan, S John; Newton, Joshua

2016-01-01

Background Preventing concussion in sport is a global challenge. To assess community-level adult male Australian Football players’ views on following the Australian Football League's (AFL) concussion guidelines. Methods 3 focus groups, each comprising 6 players from 1 regional league, were conducted until saturation of issues raised. Discussions followed a semistructured script and were audio-recorded and transcribed verbatim. Thematic analysis was conducted by 2 coders independently. Results Identified advantages of the guidelines included highlighting the seriousness of concussion; changing the culture around playing with concussion and shifting return-to-play decision responsibility from players to others. Disadvantages included players being removed from play unnecessarily; removal of players’ rights to decide if they are fit to play and players changing their behaviours to avoid being removed from play. Identified facilitators to guideline use included local league enforcement; broad information dissemination and impartial medically trained staff to assess concussion. Identified barriers to guideline use included players’ desire to play at all costs; external pressure that encouraged players to return to play prematurely; and inconvenience and cost. Conclusions Players generally understand that the AFL concussion guidelines protect their long-term welfare. However, their desire to play at all costs and help their team win is a common barrier to reporting concussion and adhering to guidelines. Leagues should take a lead role by mandating and enforcing the use of the guidelines and educating coaches, game day medical providers and players. The return-to-play component of the guidelines is complex and needs further consideration in the context of community sport. PMID:28890801

The health profile of professional soccer players: future opportunities for injury prevention.

PubMed

Volpi, Piero; Taioli, Emanuela

2012-12-01

Injuries are a major adverse event during a soccer player's career; they require medical and surgical treatment and rehabilitation and thus may interrupt the player's activity, often with severe physical and psychological sequel. Specialists have tried to identify the risk factors for injuries, in an attempt to discover predictors that could be prevented and or eliminated before the injury occurs, but the results are scarce. This article reviews the epidemiology of the frequency and occurrence of injuries in Italian soccer players, reports a list of preventable risk factors that are associated with injuries, and identifies preventable risk factors. We have identified personal factors (age, previous traumatic events, physical and biological characteristics of the player, life style habits such as smoking, alcohol, and diet, changes in physical-athletic aspects of the players, such as increased muscle strength, and use of medications) as possible risk factors for injuries. However, environmental factors such as changes in training techniques, field composition, and shoes structure may also have a major influence. This summary indicates that appropriate preventive measures can be undertaken to prevent injuries in professional soccer players. Professionals who are in close contacts with the players should be informed of the predictors of injuries and should be trained to intervene and plan appropriate preventive measures.

Concussions are associated with decreased batting performance among Major League Baseball players.

PubMed

Wasserman, Erin B; Abar, Beau; Shah, Manish N; Wasserman, Daniel; Bazarian, Jeffrey J

2015-05-01

Concussions impair balance, visual acuity, and reaction time--all of which are required for high-level batting performance--but the effects of concussion on batting performance have not been reported. The authors examined this relationship between concussion and batting performance among Major League Baseball (MLB) players. Batting performance among concussed MLB players will be worse upon return to play than batting performance among players missing time for noninjury reasons. Cohort study; Level of evidence, 3. The authors identified MLB players who sustained a concussion between 2007 and 2013 through league disabled-list records and a Baseball Prospectus database. For a comparison group, they identified players who went on paternity or bereavement leave during the same period. Using repeated-measures generalized linear models, the authors compared 7 batting metrics between the 2 groups for the 2 weeks upon return, as well as 4 to 6 weeks after return, controlling for pre-leave batting metrics, number of days missed, and position. The authors identified 66 concussions and 68 episodes of bereavement/paternity leave to include in the analysis. In the 2 weeks after return, batting average (.235 vs .266), on-base percentage (.294 vs .326), slugging percentage (.361 vs .423), and on-base plus slugging (.650 vs .749) were significantly lower among concussed players relative to the bereavement/paternity leave players (time×group interaction, P<.05). In weeks 4 to 6 after leave, these metrics were slightly lower in concussed players but not statistically significantly so. Although concussed players may be asymptomatic upon return to play, the residual effects of concussion on the skills required for batting may still be present. Further work is needed to clarify the mechanism through which batting performance after concussion is adversely affected and to identify better measures to use for return-to-play decisions. © 2015 The Author(s).

Quadriceps tendon injuries in national football league players.

PubMed

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

Participation motivation and competition anxiety among Korean and non-Korean wheelchair tennis players

PubMed Central

Jeong, Irully; Park, Sunghee

2013-01-01

The purpose of this study was to examine differences in participation motivation and competition anxiety between Korean and non-Korean wheelchair tennis players and to identify relations between participation motivation and competition anxiety in each group. Sixty-six wheel-chair tennis players who participated in the 2013 Korea Open Wheel-chair Tennis Tournament in Seoul completed the Participation Motivation Survey and the Competitive State Anxiety Inventory II. Data were analyzed by a frequency analysis, descriptive statistics, Pearson’s correlation analysis, and independent samples t-test to identify participants’ demographic characteristics, differences in participation motivation, competition anxiety between Korean and non-Korean players, and correlations between participation motivation and competition anxiety in each group. Korean players reported significantly higher motivation in purification compared to non-Korean players, whereas non-Korean players reported significantly higher motivation in enjoyment. In addition, non-Korean players demonstrated higher cognitive anxiety and self-confidence compared to Korean players. Moreover, the physical anxiety of Korean players was negatively correlated with learning, health-fitness, and enjoyment motivation. On the other hand, only self-confidence was significantly related to learning motivation and enjoyment motivation in non-Korean players. Thus, the results presented herein provide evidence for the development of specialized counseling programs that consider the psychological characteristics of Korean wheelchair tennis players. PMID:24409429

Physiological characteristics of elite soccer players.

PubMed

Tumilty, D

1993-08-01

Soccer is one of the most popular sports in the world. There is still much uncertainty and debate surrounding its physiological requirements because emphasis is on skills to the neglect of fitness, conservative training methods and the difficulty of studying the sport scientifically. The frequently found values for total distance covered in a game of about 10 km and an above-average, though not outstanding, maximum oxygen uptake of 60 ml/kg/min suggest a moderate overall aerobic demand. A comparison of top teams and players with less able participants indicates that the components of anaerobic fitness-speed, power, strength and the capacity of the lactic acid system may differentiate better between the 2 groups. Generally, there is a reduction in the level of activity in the second half of games compared with the first. There is some evidence that increased aerobic fitness may help counteract this. Progressively lower muscle glycogen stores are one likely cause of reduction in activity, and nutrition also appears to be a key factor in minimising performance deterioration, both in terms of overall diet and, more particularly, the ingestion of carbohydrates immediately before, during and after a game. There are evolutionary trends in the sport such as greater frequency of games, changes in the roles of players, and new strategies and tactics which are placing increasing demands on the all-round fitness of players. Many studies indicate scope for improvement in player fitness. The challenge for coaches and players is to meet these fitness requirements without sacrificing the skill work which makes the sport unique.

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

PubMed

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.

The Mental Skills Training of University Soccer Players

ERIC Educational Resources Information Center

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…

Identification and Classification of Player Types in Massive Multiplayer Online Games Using Avatar Behavior

DTIC Science & Technology

2011-08-01

display specific characteristics that can be used to identify the player behind the avatar. This kind of information can be used by game companies to...bring in players. This kind of information can also be used to identify deviant behaviors such as ‘gold farming.’ Gold farming refers to the practice...unique behaviors associated with a player controlling the avatar. Some of the observable information used to identify these unique behaviors are

Shoulder pain among high-level volleyball players and preseason features.

PubMed

Forthomme, Benedicte; Wieczorek, Valerie; Frisch, Anne; Crielaard, Jean-Michel; Croisier, Jean-Louis

2013-10-01

The main goal of this prospective study was to identify the most significant intrinsic risk factors for shoulder pain by measuring strength developed by shoulder rotators and by carrying out various morphostatic assessments. Sixty-six players (mean ± SD age = 24 ± 5 yr) were recruited from nine volleyball teams from the first and second divisions (34 men and 32 women) to participate in the study. Before the start of the volleyball season, all the participants completed a preseason questionnaire and underwent both a bilateral isokinetic evaluation of the shoulders and morphostatic measurements. During the subsequent 6 months of the competition period, the players reported through a weekly questionnaire any shoulder pain experienced. During the ongoing season, 23% (15 of 66 players) of the volleyball players experienced dominant shoulder pain. Interestingly, participants who reported a history of dominant shoulder pain were found to have nine times higher risk of suffering further pain in their dominant shoulder. The eccentric maximal strength developed by the internal and external rotators was found to represent a protective factor in the volleyball players (respective odds ratios = 0.946, P = 0.01 and 0.94, P = 0.05). No risk factors were found among the shoulder morphostatic measurements. In our study, the evaluation of shoulder rotator muscle strength through isokinetic assessment, especially eccentric mode, appeared to be the most contributing parameter to identify risk factors for shoulder pain. This evaluation should allow to better identify players at risk.

Incidence of Stingers in Young Rugby Players.

PubMed

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

Hip Arthroscopy in High-Level Baseball Players.

PubMed

Byrd, J W Thomas; Jones, Kay S

2015-08-01

To report the results of hip arthroscopy among high-level baseball players as recorded by outcome scores and return to baseball. All patients undergoing hip arthroscopy were prospectively assessed with the modified Harris Hip Score. On review of all procedures performed over a 12-year period, 44 hips were identified among 41 intercollegiate or professional baseball players who had achieved 2-year follow-up. Among the 41 players, follow-up averaged 45 months (range, 24 to 120 months), with a mean age of 23 years (range, 18 to 34 years). There were 23 collegiate (1 bilateral) and 18 professional (2 bilateral) baseball players, including 10 Major League Baseball players. Of the 8 Major League Baseball pitchers, 6 (75%) also underwent ulnar collateral ligament elbow surgery. Improvement in the modified Harris Hip Score averaged 13 points (from 81 points preoperatively to 94 points postoperatively); a paired-samples t test determined that this mean improvement of 13 points was statistically significant (P < .001). Players returned to baseball after 42 of 44 procedures (95%) at a mean of 4.3 months (range, 3 to 8 months), with 90% regaining the ability to participate at their previous level of competition. There were no complications. Three players (1 bilateral) underwent repeat arthroscopy. This study supports the idea that arthroscopic treatment for a variety of hip pathologies in high-level baseball players provides a successful return to sport and improvement in functional outcome scores. Level IV, therapeutic case series. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Efficiently detecting outlying behavior in video-game players

PubMed Central

Kim, Young Bin; Kang, Shin Jin; Lee, Sang Hyeok; Jung, Jang Young; Kam, Hyeong Ryeol; Lee, Jung; Kim, Young Sun; Lee, Joonsoo

2015-01-01

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. PMID:26713250

Arm pain in youth baseball players: a survey of healthy players.

PubMed

Makhni, Eric C; Morrow, Zachary S; Luchetti, Timothy J; Mishra-Kalyani, Pallavi S; Gualtieri, Anthony P; Lee, Randall W; Ahmad, Christopher S

2015-01-01

Overuse injury in youth baseball players is increasing in prevalence, and these injuries have been correlated to pitching mechanics and pitch counts/types. Prior studies regarding arm pain in these athletes have focused simply on presence or absence of pain during the season rather than on detailed factors related to arm pain with respect to frequency, severity, and associated performance and psychosocial effect. The goal of this study was to investigate frequency, quality, and effect of arm pain in healthy youth baseball players. The hypothesis was that arm pain will affect a majority of healthy baseball players and will be associated with adverse psychosocial effects. Descriptive epidemiological study. A novel survey focusing on arm pain in youth baseball players was developed for the purpose of this study. Survey questions were formulated by a consortium of trainers, clinicians, and coaches. Surveys were administered to healthy youth baseball players throughout the states of New Jersey and New York. A total of 203 healthy players completed the survey; 23% of players (n=47) reported a prior overuse injury. Only 26% and 20% of players reported that their arm never hurt when throwing or the day after throwing, respectively; 30% of players reported that arm pain at least sometimes caused them to have less fun playing; and 46% of players reported at least once being encouraged to keep playing despite having arm pain. Pitchers were more likely to report arm pain while throwing and the day after throwing and to indicate that arm pain held them back from being a better player (all P<.05). Those with prior overuse injury were more likely to have arm pain while throwing, to have arm fatigue during a game or practice, and to be encouraged to keep playing despite having pain (all P<.05). A majority of healthy (actively competing) youth baseball players report at least some baseline arm pain and fatigue, and many players suffer adverse psychosocial effects from this pain. �

Network theory inspired analysis of time-resolved expression data reveals key players guiding P. patens stem cell development.

PubMed

Busch, Hauke; Boerries, Melanie; Bao, Jie; Hanke, Sebastian T; Hiss, Manuel; Tiko, Theodhor; Rensing, Stefan A

2013-01-01

Transcription factors (TFs) often trigger developmental decisions, yet, their transcripts are often only moderately regulated and thus not easily detected by conventional statistics on expression data. Here we present a method that allows to determine such genes based on trajectory analysis of time-resolved transcriptome data. As a proof of principle, we have analysed apical stem cells of filamentous moss (P. patens) protonemata that develop from leaflets upon their detachment from the plant. By our novel correlation analysis of the post detachment transcriptome kinetics we predict five out of 1,058 TFs to be involved in the signaling leading to the establishment of pluripotency. Among the predicted regulators is the basic helix loop helix TF PpRSL1, which we show to be involved in the establishment of apical stem cells in P. patens. Our methodology is expected to aid analysis of key players of developmental decisions in complex plant and animal systems.

Discrete Event Simulation Modeling and Analysis of Key Leader Engagements

DTIC Science & Technology

2012-06-01

to offer. GreenPlayer agents require four parameters, pC, pKLK, pTK, and pRK , which give probabilities for being corrupt, having key leader...HandleMessageRequest component. The same parameter constraints apply to these four parameters. The parameter pRK is the same parameter from the CreatePlayers component...whether the local Green player has resource critical knowledge by using the parameter pRK . It schedules an EndResourceKnowledgeRequest event, passing

Preseason Strength Assessment of the Rotator Muscles and Shoulder Injury in Handball Players.

PubMed

Forthomme, Bénédicte; Croisier, Jean-Louis; Delvaux, François; Kaux, Jean-François; Crielaard, Jean-Michel; Gleizes-Cervera, Sophie

2018-02-01

  Few researchers have identified intrinsic risk factors for shoulder injury in team handball players by analyzing measurements of maximal isokinetic rotator muscle strength.   To identify possible intrinsic risk factors for shoulder injury by analyzing measurements of maximal isokinetic rotator muscle strength.   Cross-sectional study.   Male team handball senior divisions (the highest level) in France and Belgium.   A total of 108 male high-level handball players (age = 24 ± 4 years, height = 189 ± 6 cm, mass = 87 ± 11 kg) were enrolled.   All players completed a preseason questionnaire and performed a bilateral isokinetic assessment of the shoulder rotator muscles. On a monthly questionnaire, players reported any shoulder injury that they sustained during the season.   On the preseason questionnaire, 51 of 108 (47%) participants reported a history of dominant-shoulder injury. A total of 106 participants completed the in-season questionnaire, with 22% (n = 23) reporting a shoulder injury on their dominant side during the subsequent season. Fourteen percent (n = 15) sustained microtraumatic injuries, and 8% (n = 8) described a traumatic injury. Backcourt players had a 3.5-times increased risk of injury during the new season compared with players in other positions. Among the isokinetic results, no risk factor for further injury was identified in handball players with microtraumatic injuries. For traumatic injuries, the concentric maximal strength developed by the internal rotators at high speed (240°/s) in the dominant shoulder was a protective factor against the risk of further injury.   These results can potentially identify intrinsic risk factors for shoulder injury and may be used to determine potential interventions for reducing this risk in handball players.

Transcriptome profiling identifies p53 as a key player during calreticulin deficiency: Implications in lipid accumulation.

PubMed

Vig, Saurabh; Talwar, Puneet; Kaur, Kirandeep; Srivastava, Rohit; Srivastava, Arvind K; Datta, Malabika

2015-01-01

Calreticulin (CRT) is an endoplasmic reticulum (ER) resident calcium binding protein that is involved in several cellular activities. Transcriptome analyses in CRT knockdown HepG2 cells revealed 253 altered unique genes and subsequent in silico protein-protein interaction network and MCODE clustering identified 34 significant clusters, of which p53 occupied the central hub node in the highest node-rich cluster. Toward validation, we show that CRT knockdown leads to inhibition of p53 protein levels. Both, CRT and p53 siRNA promote hepatic lipid accumulation and this was accompanied by elevated SREBP-1c and FAS levels. p53 was identified to bind at -219 bp on the SREBP-1c promoter and in the presence of CRT siRNA, there was decreased occupancy of p53 on this binding element. This was associated with increased SREBP-1c promoter activity and both, mutation in this binding site or p53 over-expression antagonised the effects of CRT knockdown. We, therefore, identify a negatively regulating p53 binding site on the SREBP-1c promoter that is critical during hepatic lipid accumulation. These results were validated in mouse primary hepatocytes and toward a physiological relevance, we report that while the levels of CRT and p53 are reduced in the fatty livers of diabetic db/db mice, SREBP-1c levels are significantly elevated. Our results suggest that decreased CRT levels might be involved in the development of a fatty liver by preventing p53 occupancy on the SREBP-1c promoter and thereby facilitating SREBP-1c up-regulation and consequently, lipid accumulation.

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

ERIC Educational Resources Information Center

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,…

Physiological profiles of Hong Kong élite soccer players.

PubMed Central

Chin, M K; Lo, Y S; Li, C T; So, C H

1992-01-01

Most physiological profiles of élite soccer players originate from Western Europe and North America. Unfortunately, there is a scarcity of descriptive data on the physical characteristics of Asian soccer players. Therefore, the purpose of this study was to evaluate the physiological profiles of élite soccer players in Hong Kong. It was conducted in conjunction with the selection of the Hong Kong team before the 1990 Beijing Asian Games. In all, 24 professional soccer players were selected from a pool of 180 players as subjects for the study. The following means(s.d.) were observed: height 173.4(4.6) cm; weight 67.7(5.0) kg; body fat 7.3(3.0)%; forced vital capacity (FVC) 5.1(0.6) l; maximum oxygen uptake (VO2max) 59.1(4.9) ml kg-1 min-1; anaerobic threshold (AT 80.0(7.2)% of VO2max; alactic power index 13.5(2.4) W kg-1; lactic work index 298(27) J kg-1; peak isokinetic dominant knee extensor and flexor strengths 2.72(0.36) Nm kg-1 and 1.65(0.20) Nm kg-1. On average the physique of Hong Kong soccer players appeared to be smaller and lighter than those found in Europe, which may be one of the key factors that contribute to the lack of success of Hong Kong soccer teams in international competition. PMID:1490221

Sports hernia in National Hockey League players: does surgery affect performance?

PubMed

Jakoi, Andre; O'Neill, Craig; Damsgaard, Christopher; Fehring, Keith; Tom, James

2013-01-01

Athletic pubalgia is a complex injury that results in loss of play in competitive athletes, especially hockey players. The number of reported sports hernias has been increasing, and the importance of their management is vital. There are no studies reporting whether athletes can return to play at preinjury levels. The focus of this study was to evaluate the productivity of professional hockey players before an established athletic pubalgia diagnosis contrasted with the productivity after sports hernia repair. Cohort study; Level of evidence, 3. Professional National Hockey League (NHL) players who were reported to have a sports hernia and who underwent surgery from 2001 to 2008 were identified. Statistics were gathered on the players' previous 2 full seasons and compared with the statistics 2 full seasons after surgery. Data concerning games played, goals, average time on ice, time of productivity, and assists were gathered. Players were divided into 3 groups: group A incorporated all players, group B were players with 6 or fewer seasons of play, and group C consisted of players with 7 or more seasons of play. A control group was chosen to compare player deterioration or improvement over a career; each player selected for the study had a corresponding control player with the same tenure in his career and position during the same years. Forty-three hockey players were identified to have had sports hernia repairs from 2001 to 2008; ultimately, 80% would return to play 2 or more full seasons. Group A had statistically significant decreases in games played, goals scored, and assists. Versus the control group, the decreases in games played and assists were supported. Statistical analysis showed significant decreases in games played, goals scored, assists, and average time on ice the following 2 seasons in group C, which was also seen in comparison with the control group. Group B (16 players) showed only statistical significance in games played versus the control group

Psychopathology of Online Poker Players: Review of Literature

PubMed Central

Moreau, Axelle; Chabrol, Henri; Chauchard, Emeline

2016-01-01

Background and aims Online Texas Hold’em poker has become a spectacular form of entertainment in our society, and the number of people who use this form of gambling is increasing. It seems that online poker activity challenges existing theoretical concepts about problem gambling behaviors. The purpose of this literature review is to provide a current overview about the population of online poker players. Methods To be selected, articles had to focus on psychopathology in a sample of online poker players, be written in English or French, and be published before November 2015. A total of 17 relevant studies were identified. Results In this population, the proportion of problematic gamblers was higher than in other forms of gambling. Several factors predicting excessive gambling were identified such as stress, internal attribution, dissociation, boredom, negative emotions, irrational beliefs, anxiety, and impulsivity. The population of online poker players is largely heterogeneous, with experimental players forming a specific group. Finally, the validity of the tools used to measure excessive or problematic gambling and irrational beliefs are not suitable for assessing online poker activity. Discussion and conclusions Future studies need to confirm previous findings in the literature of online poker games. Given that skills are important in poker playing, skill development in the frames of excessive use of online poker should be explored more in depth, particularly regarding poker experience and loss chasing. Future research should focus on skills, self-regulation, and psychopathology of online poker players. PMID:27348559

Psychopathology of Online Poker Players: Review of Literature.

PubMed

Moreau, Axelle; Chabrol, Henri; Chauchard, Emeline

2016-06-01

Background and aims Online Texas Hold'em poker has become a spectacular form of entertainment in our society, and the number of people who use this form of gambling is increasing. It seems that online poker activity challenges existing theoretical concepts about problem gambling behaviors. The purpose of this literature review is to provide a current overview about the population of online poker players. Methods To be selected, articles had to focus on psychopathology in a sample of online poker players, be written in English or French, and be published before November 2015. A total of 17 relevant studies were identified. Results In this population, the proportion of problematic gamblers was higher than in other forms of gambling. Several factors predicting excessive gambling were identified such as stress, internal attribution, dissociation, boredom, negative emotions, irrational beliefs, anxiety, and impulsivity. The population of online poker players is largely heterogeneous, with experimental players forming a specific group. Finally, the validity of the tools used to measure excessive or problematic gambling and irrational beliefs are not suitable for assessing online poker activity. Discussion and conclusions Future studies need to confirm previous findings in the literature of online poker games. Given that skills are important in poker playing, skill development in the frames of excessive use of online poker should be explored more in depth, particularly regarding poker experience and loss chasing. Future research should focus on skills, self-regulation, and psychopathology of online poker players.

A new physical performance classification system for elite handball players: cluster analysis

PubMed Central

Chirosa, Ignacio J.; Robinson, Joseph E.; van der Tillaar, Roland; Chirosa, Luis J.; Martín, Isidoro Martínez

2016-01-01

Abstract The aim of the present study was to identify different cluster groups of handball players according to their physical performance level assessed in a series of physical assessments, which could then be used to design a training program based on individual strengths and weaknesses, and to determine which of these variables best identified elite performance in a group of under-19 [U19] national level handball players. Players of the U19 National Handball team (n=16) performed a set of tests to determine: 10 m (ST10) and 20 m (ST20) sprint time, ball release velocity (BRv), countermovement jump (CMJ) height and squat jump (SJ) height. All players also performed an incremental-load bench press test to determine the 1 repetition maximum (1RMest), the load corresponding to maximum mean power (LoadMP), the mean propulsive phase power at LoadMP (PMPPMP) and the peak power at LoadMP (PPEAKMP). Cluster analyses of the test results generated four groupings of players. The variables best able to discriminate physical performance were BRv, ST20, 1RMest, PPEAKMP and PMPPMP. These variables could help coaches identify talent or monitor the physical performance of athletes in their team. Each cluster of players has a particular weakness related to physical performance and therefore, the cluster results can be applied to a specific training programmed based on individual needs. PMID:28149376

Toward a Propensity-Oriented Player Typology in Educational Mobile Games

ERIC Educational Resources Information Center

Gholizadeh, Mehran; Taghiyareh, Fattaneh; Alvandkoohi, Saeed

2018-01-01

The pivotal role of identifying types of players is inevitable in the game contexts, and educational games are not an exception. This article aims to present a model of player-game interaction in the mobile game-based learning setting regarding the behavioral propensity. This model comprises five different features inherited from the player…

Epidemiology of neurodegeneration in American-style professional football players

PubMed Central

2013-01-01

The purpose of this article is to review the history of head injuries in relation to American-style football play, summarize recent research that has linked football head injuries to neurodegeneration, and provide a discussion of the next steps for refining the examination of neurodegeneration in football players. For most of the history of football, the focus of media reports and scientific studies on football-related head injuries was on the acute or short-term effects of serious, traumatic head injuries. Beginning about 10 years ago, a growing concern developed among neurologists and researchers about the long-term effects that playing professional football has on the neurologic health of the players. Autopsy-based studies identified a pathologically distinct neurodegenerative disorder, chronic traumatic encephalopathy, among athletes who were known to have experienced concussive and subconcussive blows to the head during their playing careers. Football players have been well represented in these autopsy findings. A mortality study of a large cohort of retired professional football players found a significantly increased risk of death from neurodegeneration. Further analysis found that non-line players were at higher risk than line players, possibly because of an increased risk of concussion. Although the results of the studies reviewed do not establish a cause effect relationship between football-related head injury and neurodegenerative disorders, a growing body of research supports the hypothesis that professional football players are at an increased risk of neurodegeneration. Significant progress has been made in the last few years on detecting and defining the pathology of neurodegenerative diseases. However, less progress has been made on other factors related to the progression of those diseases in football players. This review identifies three areas for further research: (a) quantification of exposure - a consensus is needed on the use of clinically

Epidemiology of neurodegeneration in American-style professional football players.

PubMed

Lehman, Everett J

2013-01-01

The purpose of this article is to review the history of head injuries in relation to American-style football play, summarize recent research that has linked football head injuries to neurodegeneration, and provide a discussion of the next steps for refining the examination of neurodegeneration in football players. For most of the history of football, the focus of media reports and scientific studies on football-related head injuries was on the acute or short-term effects of serious, traumatic head injuries. Beginning about 10 years ago, a growing concern developed among neurologists and researchers about the long-term effects that playing professional football has on the neurologic health of the players. Autopsy-based studies identified a pathologically distinct neurodegenerative disorder, chronic traumatic encephalopathy, among athletes who were known to have experienced concussive and subconcussive blows to the head during their playing careers. Football players have been well represented in these autopsy findings. A mortality study of a large cohort of retired professional football players found a significantly increased risk of death from neurodegeneration. Further analysis found that non-line players were at higher risk than line players, possibly because of an increased risk of concussion. Although the results of the studies reviewed do not establish a cause effect relationship between football-related head injury and neurodegenerative disorders, a growing body of research supports the hypothesis that professional football players are at an increased risk of neurodegeneration. Significant progress has been made in the last few years on detecting and defining the pathology of neurodegenerative diseases. However, less progress has been made on other factors related to the progression of those diseases in football players. This review identifies three areas for further research: (a) quantification of exposure - a consensus is needed on the use of clinically

Wearable flex sensor system for multiple badminton player grip identification

NASA Astrophysics Data System (ADS)

Jacob, Alvin; Zakaria, Wan Nurshazwani Wan; Tomari, Mohd Razali Bin Md; Sek, Tee Kian; Suberi, Anis Azwani Muhd

2017-09-01

This paper focuses on the development of a wearable sensor system to identify the different types of badminton grip that is used by a player during training. Badminton movements and strokes are fast and dynamic, where most of the involved movement are difficult to identify with the naked eye. Also, the usage of high processing optometric motion capture system is expensive and causes computational burden. Therefore, this paper suggests the development of a sensorized glove using flex sensor to measure a badminton player's finger flexion angle. The proposed Hand Monitoring Module (HMM) is connected to a personal computer through Bluetooth to enable wireless data transmission. The usability and feasibility of the HMM to identify different grip types were examined through a series of experiments, where the system exhibited 70% detection ability for the five different grip type. The outcome plays a major role in training players to use the proper grips for a badminton stroke to achieve a more powerful and accurate stroke execution.

Psychosocial Factors Involved in Transitions from College to Postcollege Careers for Male NCAA Division-1 Basketball Players

ERIC Educational Resources Information Center

Cummins, Paul; O'Boyle, Ian

2015-01-01

This article investigated the key psychosocial factors that impact upon National Collegiate Athletic Association (NCAA) Division-1 male basketball players, as they transition from college to postcollege athletic or nonathletic careers. Participants (N = 9) were current/former NCAA Division-1 basketball players. Four participants were selected…

Quantitative methods of identifying the key nodes in the illegal wildlife trade network

PubMed Central

Patel, Nikkita Gunvant; Rorres, Chris; Joly, Damien O.; Brownstein, John S.; Boston, Ray; Levy, Michael Z.; Smith, Gary

2015-01-01

Innovative approaches are needed to combat the illegal trade in wildlife. Here, we used network analysis and a new database, HealthMap Wildlife Trade, to identify the key nodes (countries) that support the illegal wildlife trade. We identified key exporters and importers from the number of shipments a country sent and received and from the number of connections a country had to other countries over a given time period. We used flow betweenness centrality measurements to identify key intermediary countries. We found the set of nodes whose removal from the network would cause the maximum disruption to the network. Selecting six nodes would fragment 89.5% of the network for elephants, 92.3% for rhinoceros, and 98.1% for tigers. We then found sets of nodes that would best disseminate an educational message via direct connections through the network. We would need to select 18 nodes to reach 100% of the elephant trade network, 16 nodes for rhinoceros, and 10 for tigers. Although the choice of locations for interventions should be customized for the animal and the goal of the intervention, China was the most frequently selected country for network fragmentation and information dissemination. Identification of key countries will help strategize illegal wildlife trade interventions. PMID:26080413

Identifying key genes in glaucoma based on a benchmarked dataset and the gene regulatory network.

PubMed

Chen, Xi; Wang, Qiao-Ling; Zhang, Meng-Hui

2017-10-01

The current study aimed to identify key genes in glaucoma based on a benchmarked dataset and gene regulatory network (GRN). Local and global noise was added to the gene expression dataset to produce a benchmarked dataset. Differentially-expressed genes (DEGs) between patients with glaucoma and normal controls were identified utilizing the Linear Models for Microarray Data (Limma) package based on benchmarked dataset. A total of 5 GRN inference methods, including Zscore, GeneNet, context likelihood of relatedness (CLR) algorithm, Partial Correlation coefficient with Information Theory (PCIT) and GEne Network Inference with Ensemble of Trees (Genie3) were evaluated using receiver operating characteristic (ROC) and precision and recall (PR) curves. The interference method with the best performance was selected to construct the GRN. Subsequently, topological centrality (degree, closeness and betweenness) was conducted to identify key genes in the GRN of glaucoma. Finally, the key genes were validated by performing reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A total of 176 DEGs were detected from the benchmarked dataset. The ROC and PR curves of the 5 methods were analyzed and it was determined that Genie3 had a clear advantage over the other methods; thus, Genie3 was used to construct the GRN. Following topological centrality analysis, 14 key genes for glaucoma were identified, including IL6 , EPHA2 and GSTT1 and 5 of these 14 key genes were validated by RT-qPCR. Therefore, the current study identified 14 key genes in glaucoma, which may be potential biomarkers to use in the diagnosis of glaucoma and aid in identifying the molecular mechanism of this disease.

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

PubMed

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.

Nutritional Practices of National Female Soccer Players: Analysis and Recommendations

PubMed Central

Martin, Louise; Lambeth, Anneliese; Scott, Dawn

2006-01-01

The aim of the study was to establish the nutritional practices and activity patterns of elite female soccer players. The nutritional intake of 16 female England Soccer players was self-reported over a seven-day period. Participants were provided with written and verbal guidelines for the completion of the diaries. Training details were also recorded, and used in combination with BMR predictions to calculate daily energy expenditure. Energy, macronutrient and micronutrient intakes were determined using DietMaster 4.0 software. Results suggest that energy intake was low (1904 ± 366.3 kcal) in relation to previous recommendations for soccer players. Energy expenditure (2153.5 ± 596.2 kcal) was not significantly different (p > 0.05) from intake, suggesting energy balance was achieved. Carbohydrate (53.8 ± 6.8%), protein (16.8 ± 2.1%) and fat (28.8 ± 6.6%) intakes were in line with recommendations. Fluid intake (2466 ± 1350.5ml·day-1) was sufficient to meet baseline recommendations, but would need to be higher to meet the additional requirement of training and competition. With the exception of vitamin A and iron, all micronutrient intakes were higher than the DRI. In conclusion, recommendations for female soccer players are to encourage consumption of carbohydrate-electrolyte beverages to enhance carbohydrate intake and increase fluid intake, and ensure sufficient iron rich foods are included in the diet to meet the DRI. Key points Female soccer players demonstrate a low energy intake in relation to predicted requirements, but were in energy balance in this study. Increased carbohydrate intake may be beneficial to both training and competition performance of elite female soccer players Fluid requirements should be addressed on an individual basis and matched to player requirements. The iron status of female soccer players may be compromised due to insufficient dietary intake to meet the DRV. PMID:24198690

Nutritional practices of national female soccer players: analysis and recommendations.

PubMed

Martin, Louise; Lambeth, Anneliese; Scott, Dawn

2006-01-01

The aim of the study was to establish the nutritional practices and activity patterns of elite female soccer players. The nutritional intake of 16 female England Soccer players was self-reported over a seven-day period. Participants were provided with written and verbal guidelines for the completion of the diaries. Training details were also recorded, and used in combination with BMR predictions to calculate daily energy expenditure. Energy, macronutrient and micronutrient intakes were determined using DietMaster 4.0 software. Results suggest that energy intake was low (1904 ± 366.3 kcal) in relation to previous recommendations for soccer players. Energy expenditure (2153.5 ± 596.2 kcal) was not significantly different (p > 0.05) from intake, suggesting energy balance was achieved. Carbohydrate (53.8 ± 6.8%), protein (16.8 ± 2.1%) and fat (28.8 ± 6.6%) intakes were in line with recommendations. Fluid intake (2466 ± 1350.5ml·day(-1)) was sufficient to meet baseline recommendations, but would need to be higher to meet the additional requirement of training and competition. With the exception of vitamin A and iron, all micronutrient intakes were higher than the DRI. In conclusion, recommendations for female soccer players are to encourage consumption of carbohydrate-electrolyte beverages to enhance carbohydrate intake and increase fluid intake, and ensure sufficient iron rich foods are included in the diet to meet the DRI. Key pointsFemale soccer players demonstrate a low energy intake in relation to predicted requirements, but were in energy balance in this study.Increased carbohydrate intake may be beneficial to both training and competition performance of elite female soccer playersFluid requirements should be addressed on an individual basis and matched to player requirements.The iron status of female soccer players may be compromised due to insufficient dietary intake to meet the DRV.

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

PubMed

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

The Relative Age Effect and Physical Fitness Characteristics in German Male Tennis Players

PubMed Central

Ulbricht, Alexander; Fernandez-Fernandez, Jaime; Mendez-Villanueva, Alberto; Ferrauti, Alexander

2015-01-01

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. Key points RAEsexist in the selection of youth tennis players in Germany, a greater percentage of players analyzed was born in the 1st quarter compared to all licensed tennis players in the country, and more pronounced with an increased competition level in youth players. Players born later in the selection year and still selected in elite squads were likely to be similar across a range of physical fitness attributes compared with those born earlier in the year. The selection process should be reevaluated and changed to reduce the impact of RAEs on tennis players. PMID:26336351

Identifying Key Attributes for Protein Beverages.

PubMed

Oltman, A E; Lopetcharat, K; Bastian, E; Drake, M A

2015-06-01

This study identified key attributes of protein beverages and evaluated effects of priming on liking of protein beverages. An adaptive choice-based conjoint study was conducted along with Kano analysis to gain insight on protein beverage consumers (n = 432). Attributes evaluated included label claim, protein type, amount of protein, carbohydrates, sweeteners, and metabolic benefits. Utility scores for levels and importance scores for attributes were determined. Subsequently, two pairs of clear acidic whey protein beverages were manufactured that differed by age of protein source or the amount of whey protein per serving. Beverages were evaluated by 151 consumers on two occasions with or without priming statements. One priming statement declared "great flavor," the other priming statement declared 20 g protein per serving. A two way analysis of variance was applied to discern the role of each priming statement. The most important attribute for protein beverages was sweetener type, followed by amount of protein, followed by type of protein followed by label claim. Beverages with whey protein, naturally sweetened, reduced sugar and ≥15 g protein per serving were most desired. Three consumer clusters were identified, differentiated by their preferences for protein type, sweetener and amount of protein. Priming statements positively impacted concept liking (P < 0.05) but had no effect on overall liking (P > 0.05). Consistent with trained panel profiles of increased cardboard flavor with higher protein content, consumers liked beverages with 10 g protein more than beverages with 20 g protein (6.8 compared with 5.7, P < 0.05). Protein beverages must have desirable flavor for wide consumer appeal. © 2015 Institute of Food Technologists®

Exploring Stereotypical Perceptions of Female Players in Digital Gaming Contexts.

PubMed

Kaye, Linda K; Gresty, Claire E; Stubbs-Ennis, Natasha

2017-12-01

Gender stereotypes are still reported to exist in digital gaming contexts, despite the fact that participation of females is relatively equal to that of males. The current research explored a number of factors and their impact upon stereotypical perceptions and attitudes toward female players. This included avatar gender, gender identity by gaming context, as well as more general gender-role beliefs. We undertook two studies, each utilizing an online questionnaire targeted toward online players. Study 1 recruited online gamers (N = 489) and compared competence perceptions of players, which varied by player gender (male, female) and avatar gender (male, female), whereby four conditions were established. Overall, player competence was perceived to be highest when male avatars were used, specifically when female players were depicted in this way. Study 2 explored the relationships between male social identity and gender-role beliefs, with sexist attitudes in gaming, and whether this varied by gaming context (massively multiplayer online [MMO] vs. first-person shooter [FPS]). Male online gamers (N = 193) were recruited, of which 112 were MMO players, and 81 were FPS players. It was found that identifying as male social identity was not related to sexist attitudes in either gaming context. However, more general gender-role beliefs were related to sexist attitudes. The findings indicate that although certain stereotypes exist (e.g., competence perceptions), these are not necessarily harvested by players' identities within communities, but may derive through more operational functions such as avatar gender.

Impact locations and concussion outcomes in high school football player-to-player collisions.

PubMed

Kerr, Zachary Y; Collins, Christy L; Mihalik, Jason P; Marshall, Stephen W; Guskiewicz, Kevin M; Comstock, R Dawn

2014-09-01

Little research has examined concussion outcomes in terms of impact location (ie, the area on the head in which the impact occurred). This study describes the epidemiology of concussions resulting from player-to-player collision in high school football by impact location. National High School Sports-Related Injury Surveillance Study data (2008/2009-2012/2013) were analyzed to calculate rates and describe circumstances of football concussion (eg, symptomology, symptom resolution time, return to play) resulting from player-to-player collisions by impact location (ie, front-, back-, side-, and top-of-the-head). Most concussions resulting from player-to-player collisions occurred from front-of-the-head (44.7%) and side-of-the-head (22.3%) impacts. Number of symptoms reported, prevalence of reported symptoms, symptom resolution time, and length of time to return to play were not associated with impact location. However, a larger proportion of football players sustaining concussions from top-of-the-head impacts experienced loss of consciousness (8.0%) than those sustaining concussions from impacts to other areas of the head (3.5%) (injury proportion ratio 2.3; 95% confidence interval 1.2-4.2; P = .008). Players had their head down at the time of impact in a higher proportion of concussions caused by top-of-the-head impacts (86.4%) than concussions from impacts to other areas of the head (24.0%) (injury proportion ratio 3.6; 95% confidence interval 3.2-4.0; P < .001). Among high school football players who sustained concussions due to player-to-player collisions, concussion outcomes were generally independent of impact location. Recommended strategies for reducing the proportion of top-of-the-head impacts include improved education regarding tackling with proper "head-up" technique. Copyright © 2014 by the American Academy of Pediatrics.

Social Network Analysis Identifies Key Participants in Conservation Development.

PubMed

Farr, Cooper M; Reed, Sarah E; Pejchar, Liba

2018-05-01

Understanding patterns of participation in private lands conservation, which is often implemented voluntarily by individual citizens and private organizations, could improve its effectiveness at combating biodiversity loss. We used social network analysis (SNA) to examine participation in conservation development (CD), a private land conservation strategy that clusters houses in a small portion of a property while preserving the remaining land as protected open space. Using data from public records for six counties in Colorado, USA, we compared CD participation patterns among counties and identified actors that most often work with others to implement CDs. We found that social network characteristics differed among counties. The network density, or proportion of connections in the network, varied from fewer than 2 to nearly 15%, and was higher in counties with smaller populations and fewer CDs. Centralization, or the degree to which connections are held disproportionately by a few key actors, was not correlated strongly with any county characteristics. Network characteristics were not correlated with the prevalence of wildlife-friendly design features in CDs. The most highly connected actors were biological and geological consultants, surveyors, and engineers. Our work demonstrates a new application of SNA to land-use planning, in which CD network patterns are examined and key actors are identified. For better conservation outcomes of CD, we recommend using network patterns to guide strategies for outreach and information dissemination, and engaging with highly connected actor types to encourage widespread adoption of best practices for CD design and stewardship.

A comparison of static near stereo acuity in youth baseball/softball players and non-ball players.

PubMed

Boden, Lauren M; Rosengren, Kenneth J; Martin, Daniel F; Boden, Scott D

2009-03-01

Although many aspects of vision have been investigated in professional baseball players, few studies have been performed in developing athletes. The issue of whether youth baseball players have superior stereopsis to nonplayers has not been addressed specifically. The purpose of this study was to determine if youth baseball/softball players have better stereo acuity than non-ball players. Informed consent was obtained from 51 baseball/softball players and 52 non-ball players (ages 10 to 18 years). Subjects completed a questionnaire, and their static near stereo acuity was measured using the Randot Stereotest (Stereo Optical Company, Chicago, Illinois). Stereo acuity was measured as the seconds of arc between the last pair of images correctly distinguished by the subject. The mean stereo acuity score was 25.5 +/- 1.7 seconds of arc in the baseball/softball players and 56.2 +/- 8.4 seconds of arc in the non-ball players. This difference was statistically significant (P < 0.00001). In addition, a perfect stereo acuity score of 20 seconds of arc was seen in 61% of the ball players and only 23% of the non-ball players (P = 0.0001). Youth baseball/softball players had significantly better static stereo acuity than non-ball players, comparable to professional ball players.

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

ERIC Educational Resources Information Center

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…

The key to success in elite athletes? Explicit and implicit motor learning in youth elite and non-elite soccer players.

PubMed

Verburgh, L; Scherder, E J A; van Lange, P A M; Oosterlaan, J

2016-09-01

In sports, fast and accurate execution of movements is required. It has been shown that implicitly learned movements might be less vulnerable than explicitly learned movements to stressful and fast changing circumstances that exist at the elite sports level. The present study provides insight in explicit and implicit motor learning in youth soccer players with different expertise levels. Twenty-seven youth elite soccer players and 25 non-elite soccer players (aged 10-12) performed a serial reaction time task (SRTT). In the SRTT, one of the sequences must be learned explicitly, the other was implicitly learned. No main effect of group was found for implicit and explicit learning on mean reaction time (MRT) and accuracy. However, for MRT, an interaction was found between learning condition, learning phase and group. Analyses showed no group effects for the explicit learning condition, but youth elite soccer players showed better learning in the implicit learning condition. In particular, during implicit motor learning youth elite soccer showed faster MRTs in the early learning phase and earlier reached asymptote performance in terms of MRT. Present findings may be important for sports because children with superior implicit learning abilities in early learning phases may be able to learn more (durable) motor skills in a shorter time period as compared to other children.

Frontal lobe function in chess players.

PubMed

Nejati, Majid; Nejati, Vahid

2012-01-01

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 don't have any preference in any stage of Stroop test. Chess players don't have any preference in selective attention, inhibition and executive cognitive function. Chess players' have lower shifting abilities than non-players.

Camus' Actor as Tom Stoppard's Player; A Key to Interpreting "Rosencrantz and Guildenstern Are Dead."

ERIC Educational Resources Information Center

Zivanovic, Judith

An examination of Albert Camus' definition of the actor in "The Myth on Sisyphus" helps to illuminate the character and role of The Player in Tom Stoppard's play and, hence, to bring light to an understanding of the philosophy of the play itself. The actor, for Camus, reveals our mortality in the face of the absurdity of our mortality,…

Distinct cut task strategy in Australian football players with a history of groin pain.

PubMed

Edwards, Suzi; Brooke, Hiram C; Cook, Jill L

2017-01-01

This study aimed to explore the differences in the magnitude of movement variability and strategies utilized during an unanticipated cut task between players with and without a history of groin pain. Cross-sectional design. Biomechanics laboratory. Male Australian football players with (HISTORY; n = 7) or without (CONTROL; n = 10) a history of groin pain. Three-dimensional ground reaction forces (GRF) and kinematics were recorded during 10 successful trials of an unanticipated cut task, and isokinetic hip adduction and abduction strength. Between-group differences were determined using independent-samples t-tests and the coefficient of variation (CV). Key substantial between-group differences identified were that the HISTORY group displayed decreased knee flexion and hip internal rotation, increased knee internal rotation and T12-L1 right rotation, and higher GRFs during the cut task. They also utilized three invariant systems (ankle, knee and T12-L1 joints), while being connected by a segment (hip and L5-S1 joints) that displayed increased lumbopelvic movement during the cut task, and decreased adductor muscle strength. This identifies the need for clinical management of the lower limb and thoracic segment to improve functional movement patterns in athletes with a history of a groin injury. Copyright © 2016 Elsevier Ltd. All rights reserved.

The incidence and distribution of stress fractures in elite tennis players

PubMed Central

Maquirriain, J; Ghisi, J P

2006-01-01

Background Modern professional tennis involves powerful movements repeatedly subjecting the musculoskeletal system to heavy mechanical load. Thus tennis players are exposed to high risk of overuse injuries including stress fractures. Objective To determine the incidence and distribution of stress fractures in elite tennis players. Study design Retrospective cohort study. Methods The cohort study population consisted of 139 elite players (mean (SD) age, 20.0 (5.0) years; 48 female, 91 male). Stress fractures were identified and confirmed radiologically from medical records during a two year period. Injuries were analysed according to age, sex, site, severity, delay in diagnosis, and time needed to return to sports. Results 15 players sustained 18 stress fractures, corresponding to an overall case incidence of 12.9% (95% confidence interval (CI), 8.1 to 20.0). The tarsal navicular was most affected (n = 5; 27%), followed by the pars interarticularis (n = 3; 16%), the metatarsals (n = 3; 16%), the tibia (n = 2; 11%) and the lunate (n = 2; 11%). Magnetic resonance imaging showed a greater incidence of “high grade” lesions (94.4%). Stress fracture incidence was significantly higher in juniors (20.3% (95% CI, 11.4 to 33.2)) than in professional players (7.5% (2.8 to 15.6)) (p = 0.045). Conclusions There was a high absolute risk (12.9%) of stress fractures in elite tennis players over a two year period. Junior players were at highest risk. The lesions are a major cause of disruption both of training and of competition. Risk factors should therefore be identified and prevention emphasised. PMID:16632579

Performance Outcomes After Metacarpal Fractures in National Basketball Association Players.

PubMed

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.

Performance Outcomes After Metacarpal Fractures in National Basketball Association Players

PubMed Central

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

2016-01-01

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. PMID:28149209

Somatotype of Competitive Youth Soccer Players From Brazil

PubMed Central

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

2014-01-01

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. PMID:25414758

Integrated RNA-Seq and sRNA-Seq Analysis Identifies Chilling and Freezing Responsive Key Molecular Players and Pathways in Tea Plant (Camellia sinensis).

PubMed

Zheng, Chao; Zhao, Lei; Wang, Yu; Shen, Jiazhi; Zhang, Yinfei; Jia, Sisi; Li, Yusheng; Ding, Zhaotang

2015-01-01

Tea [Camellia sinensis (L) O. Kuntze, Theaceae] is one of the most popular non-alcoholic beverages worldwide. Cold stress is one of the most severe abiotic stresses that limit tea plants' growth, survival and geographical distribution. However, the genetic regulatory network and signaling pathways involved in cold stress responses in tea plants remain unearthed. Using RNA-Seq, DGE and sRNA-Seq technologies, we performed an integrative analysis of miRNA and mRNA expression profiling and their regulatory network of tea plants under chilling (4℃) and freezing (-5℃) stress. Differentially expressed (DE) miRNA and mRNA profiles were obtained based on fold change analysis, miRNAs and target mRNAs were found to show both coherent and incoherent relationships in the regulatory network. Furthermore, we compared several key pathways (e.g., 'Photosynthesis'), GO terms (e.g., 'response to karrikin') and transcriptional factors (TFs, e.g., DREB1b/CBF1) which were identified as involved in the early chilling and/or freezing response of tea plants. Intriguingly, we found that karrikins, a new group of plant growth regulators, and β-primeverosidase (BPR), a key enzyme functionally relevant with the formation of tea aroma might play an important role in both early chilling and freezing response of tea plants. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis further confirmed the results from RNA-Seq and sRNA-Seq analysis. This is the first study to simultaneously profile the expression patterns of both miRNAs and mRNAs on a genome-wide scale to elucidate the molecular mechanisms of early responses of tea plants to cold stress. In addition to gaining a deeper insight into the cold resistant characteristics of tea plants, we provide a good case study to analyse mRNA/miRNA expression and profiling of non-model plant species using next-generation sequencing technology.

Risk Factors for Injuries in Professional Football Players.

PubMed

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 < 0.01), age (OR = 2.05; 95% CI = 1.49-2.81, p < 0.01) and a previous injury (OR = 4.4; 95% CI = 2.14-9.07, p < 0.01) were significantly correlated to increased risk of injuries. Body mass index was not associated with risk of injury. Strains (34.19%) and sprains (25.81%) were the major injury types. Twenty-seven percent of injured players were absent from 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.

A Cross-Continental Study on Children's Drawings of Football Players: Implications for Understanding Key Issues and Controversies in Human Figure Drawings

PubMed Central

Baluch, Bahman; Duffy, Linda J.; Badami, Rokhsareh; Pereira, Elisangela C. Ap

2017-01-01

Professionals examine various aspects of girls’ and boys’ drawings as a way of understanding their intelligence, personality and emotional state. However, the extent to which such measures could be universally generalised or attributed to a specific cultural norm is still a debatable issue. In the present study five key features of children’s drawings namely: the size (height) of the drawings, profile or full face, figure in action or static, shaded or non-shaded and the nature of additional details were examined from a cross-cultural perspective, and by providing a topic (football) for which children’s drawing of a human figure could provide opportunities for the latter indices to manifest and flourish. Children from three countries; England, Iran and Brazil, representing three continents took part in this study. The participants were asked to draw a football player from their own country and from the other participating countries. The results showed that Brazilian children differ from Iranian and English children by drawing significantly smaller figures and putting more football action in the drawings. Shading of the figure drawn was more prevalent amongst English children. Such findings have implications for the interpretation of key aspects of children's drawings in educational, clinical and therapeutic settings and from a universal vs. culturally-specific viewpoint. PMID:28904595

A Cross-Continental Study on Children's Drawings of Football Players: Implications for Understanding Key Issues and Controversies in Human Figure Drawings.

PubMed

Baluch, Bahman; Duffy, Linda J; Badami, Rokhsareh; Pereira, Elisangela C Ap

2017-08-01

Professionals examine various aspects of girls' and boys' drawings as a way of understanding their intelligence, personality and emotional state. However, the extent to which such measures could be universally generalised or attributed to a specific cultural norm is still a debatable issue. In the present study five key features of children's drawings namely: the size (height) of the drawings, profile or full face, figure in action or static, shaded or non-shaded and the nature of additional details were examined from a cross-cultural perspective, and by providing a topic (football) for which children's drawing of a human figure could provide opportunities for the latter indices to manifest and flourish. Children from three countries; England, Iran and Brazil, representing three continents took part in this study. The participants were asked to draw a football player from their own country and from the other participating countries. The results showed that Brazilian children differ from Iranian and English children by drawing significantly smaller figures and putting more football action in the drawings. Shading of the figure drawn was more prevalent amongst English children. Such findings have implications for the interpretation of key aspects of children's drawings in educational, clinical and therapeutic settings and from a universal vs. culturally-specific viewpoint.

Neuromuscular Risk Factors for Knee and Ankle Ligament Injuries in Male Youth Soccer Players

PubMed Central

Read, Paul J.; Oliver, Jon L.; De Ste Croix, Mark B. A.; Myer, Gregory D.; Lloyd, Rhodri S.

2017-01-01

Injuries reported in male youth soccer players most commonly occur in the lower extremities, and include a high proportion of ligament sprains at the ankle and knee with a lower proportion of overuse injuries. There is currently a paucity of available literature that examines age- and sex-specific injury risk factors for such injuries within youth soccer players. Epidemiological data have reported movements that lead to non-contact ligament injury include running, twisting and turning, over-reaching and landing. Altered neuromuscular control during these actions has been suggested as a key mechanism in females and adult populations; however, data available in male soccer players is sparse. The focus of this article is to review the available literature and elucidate prevalent risk factors pertaining to male youth soccer players which may contribute to their relative risk of injury. PMID:26856339

Neuromuscular Risk Factors for Knee and Ankle Ligament Injuries in Male Youth Soccer Players.

PubMed

Read, Paul J; Oliver, Jon L; De Ste Croix, Mark B A; Myer, Gregory D; Lloyd, Rhodri S

2016-08-01

Injuries reported in male youth soccer players most commonly occur in the lower extremities, and include a high proportion of ligament sprains at the ankle and knee with a lower proportion of overuse injuries. There is currently a paucity of available literature that examines age- and sex-specific injury risk factors for such injuries within youth soccer players. Epidemiological data have reported movements that lead to non-contact ligament injury include running, twisting and turning, over-reaching and landing. Altered neuromuscular control during these actions has been suggested as a key mechanism in females and adult populations; however, data available in male soccer players is sparse. The focus of this article is to review the available literature and elucidate prevalent risk factors pertaining to male youth soccer players which may contribute to their relative risk of injury.

Key attributes of expert NRL referees.

PubMed

Morris, Gavin; O'Connor, Donna

2017-05-01

Experiential knowledge of elite National Rugby League (NRL) referees was investigated to determine the key attributes contributing to expert officiating performance. Fourteen current first-grade NRL referees were asked to identify the key attributes they believed contributed to their expert refereeing performance. The modified Delphi method involved a 3-round process of an initial semi-structured interview followed by 2 questionnaires to reach consensus of opinion. The data revealed 25 attributes that were rated as most important that underpin expert NRL refereeing performance. Results illustrate the significance of the cognitive category, with the top 6 ranked attributes all cognitive skills. Of these, the referees ranked decision-making accuracy as the most important attribute, followed by reading the game, communication, game understanding, game management and knowledge of the rules. Player rapport, positioning and teamwork were the top ranked game skill attributes underpinning performance excellence. Expert referees also highlighted a number of psychological attributes (e.g., concentration, composure and mental toughness) that were significant to performance. There were only 2 physiological attributes (fitness, aerobic endurance) that were identified as significant to elite officiating performance. In summary, expert consensus was attained which successfully provided a hierarchy of the most significant attributes of expert NRL refereeing performance.

Seasonal Body Composition Variation Amongst Elite European Professional Soccer Players: An Approach of Talent Identification

PubMed Central

Owen, Adam Lee; Lago-Peñas, Carlos; Dunlop, Gordon; Mehdi, Rouissi; Chtara, Moktar; Dellal, Alexandre

2018-01-01

Abstract The primary aim of the investigation was to study the seasonal changes in body composition in elite European soccer players and identify key playing positional differences. Twenty-two players (age = 24 ± 3.7 years, body height = 180.45 ± 5.12 cm, body mass = 76.66 ± 5.34 kg) were tested. Players’ mass (kg), lean body mass (LBM), fat free mass (FFM), fat mass (FM), muscle girths (MG) and sum of 8 skinfolds (mm) were measured across 5 time points (T0 = Start of pre-season training; T1 = End of pre-season training; T2 = Mid-season; T3 = End of mid-season break; T4 = End of season). Players were divided into their tactical positional roles for analysis. The specific positions they were divided into included defenders (n = 8), midfielders (n = 8) and forwards (n = 6). Assessment of training and matchplay exposure were also recorded. Sites-4, Sites-7, Sites-8 and Fat Mass decreased dramatically from T0 to T1 and T2 in all playing positions (p < 0.01), while no remarkable differences were found between T2, T3 and T4. Except for defenders, calf girth and lean mass were higher in T2, T3 and T4 compared to T0 and T1 (p < 0.01). Midfielders were found to be leaner than forwards and defenders in all data collection time point sessions. Defenders showed higher values in calf girth and lean body mass than midfielders and forwards. It can be concluded from this investigation that there are large variances n positional body composition profiles amongst professional European soccer players. Furthermore, significant changes are prevalent and occur across the season from LBM, FFM, MG and skinfold assessment amongst European elite level soccer players. PMID:29922389

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

PubMed Central

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

2014-01-01

majority of retired players had normal clinical mental status and central nervous system (CNS) neurological examinations. Four players (9%) had microbleeds in brain parenchyma identified in SWI, and 3 (7%) had a large cavum septum pellucidum with brain atrophy. The number of concussions/dings was associated with abnormal results in SWI and DTI. Neuropsychological testing revealed isolated impairments in 11 players (24%), but none had dementia. Nine players (20%) endorsed symptoms of moderate or severe depression on the BDI and/or met criteria for depression on PHQ; however, none had dementia, dysarthria, parkinsonism, or cerebellar dysfunction. The number of football-related concussions was associated with isolated abnormalities on the clinical neurological examination, suggesting CNS dysfunction. The APOE4 allele was present in 38% of the players, a larger number than would be expected in the general male population (23%-26%). Conclusion: MRI lesions and neuropsychological impairments were found in some players; however, the majority of retired NFL players had no clinical signs of chronic brain damage. Clinical Relevance: These results need to be reconciled with the prevailing view that a career in football frequently results in chronic brain damage. PMID:25177413

The Physiological Profile of Junior Soccer Players at SSBB Surabaya Bhakti

NASA Astrophysics Data System (ADS)

Nashirudin, M.; Kusnanik, N. W.

2018-01-01

Soccer players are required to have good physical fitness in order to achieve optimum accomplishment; physical fitness stands as the foundation of technical and tactical proficiency as well as the mental maturity during the matches. The purpose of this study was to identify the physiological profile of junior soccer players of SSB Surabaya Bhakti age 16-17. The research was conducted at 20 junior soccer players. This research was quantitative with descriptive analysis. Data were collected by testing of physiological (anaerobic power and capacity including explosive leg power, speed, agility; aerobic capacity: cardiovascular endurance). Data was analyzed using percentage. The result showed that the percentage of explosive leg power of junior soccer players were 30% (good category), speed was 85% (average category), right agility was 90% (average category), left agility was 75% (average category). On the other hand, the aerobic power and capacity of the junior soccer players in this study was 50% (average category). The conclusion of this research is that the physiological profile of junior soccer players at SSB Surabaya Bhakti age 16-17 was majority in average category.

The common molecular players in plant hormone crosstalk and signaling.

PubMed

Ohri, Puja; Bhardwaj, Renu; Bali, Shagun; Kaur, Ravinderjit; Jasrotia, Shivam; Khajuria, Anjali; Parihar, Ripu D

2015-01-01

Plant growth and development is under the control of mutual interactions among plant hormones. The five classical categories of plant hormones include auxins, cytokinins, gibberellins, abscisic acid and ethylene. Additionally, newer classes of plant hormones have been recognized like brassinosteroids, jasmonic acid, salicylic acid and polyamines. These hormones play significant roles in regulating the plant growth and development. Various receptors and key signaling components of these hormones have been studied and identified. At genetic level, crosstalk among the various plant hormones is found to be antagonistic or synergistic. In addition, components of signaling pathway of one plant hormone interact with the signaling components of other hormone. Thus, an attempt has been made to review the literature regarding the role of plant hormones in plant physiology and the common molecular players in their signaling and crosstalk.

Bruton's Tyrosine Kinase: An Emerging Key Player in Innate Immunity.

PubMed

Weber, Alexander N R; Bittner, Zsofia; Liu, Xiao; Dang, Truong-Minh; Radsak, Markus Philipp; Brunner, Cornelia

2017-01-01

Bruton's tyrosine kinase (BTK) was initially discovered as a critical mediator of B cell receptor signaling in the development and functioning of adaptive immunity. Growing evidence also suggests multiple roles for BTK in mononuclear cells of the innate immune system, especially in dendritic cells and macrophages. For example, BTK has been shown to function in Toll-like receptor-mediated recognition of infectious agents, cellular maturation and recruitment processes, and Fc receptor signaling. Most recently, BTK was additionally identified as a direct regulator of a key innate inflammatory machinery, the NLRP3 inflammasome. BTK has thus attracted interest not only for gaining a more thorough basic understanding of the human innate immune system but also as a target to therapeutically modulate innate immunity. We here review the latest developments on the role of BTK in mononuclear innate immune cells in mouse versus man, with specific emphasis on the sensing of infectious agents and the induction of inflammation. Therapeutic implications for modulating innate immunity and critical open questions are also discussed.

Three-Compartment Body Composition in Academy and Senior Rugby League Players.

PubMed

Till, Kevin; Jones, Ben; O'Hara, John; Barlow, Matthew; Brightmore, Amy; Lees, Matthew; Hind, Karen

2016-03-01

To compare the body size and 3-compartment body composition between academy and senior professional rugby league players using dual-energy X-ray absorptiometry (DXA). Academy (age 18.1 ± 1.1 y, n = 34) and senior (age 26.2 ± 4.6 y, n = 63) rugby league players received 1 total-body DXA scan. Height, body mass, and body-fat percentage alongside total and regional fat mass, lean mass, and bone mineral content (BMC) were compared. Independent t tests with Cohen d effect sizes and multivariate analysis of covariance (MANCOVA), controlling for height and body mass, with partial eta-squared (η2) effect sizes, were used to compare total and regional body composition. Senior players were taller (183.2 ± 5.8 vs 179.2 ± 5.7 cm, P = .001, d = 0.70) and heavier (96.5 ± 9.3 vs 86.5 ± 9.0 kg, P < .001, d = 1.09) with lower body-fat percentage (16.3 ± 3.7 vs 18.0 ± 3.7%, P = .032, d = 0.46) than academy players. MANCOVA identified significant overall main effects for total and regional body composition between academy and senior players. Senior players had lower total fat mass (P < .001, η2 = 0.15), greater total lean mass (P < .001, η2 = 0.14), and greater total BMC (P = .001, η2 = 0.12) than academy players. For regional sites, academy players had significantly greater fat mass at the legs (P < .001, η2 = 0.29) than senior players. The lower age, height, body mass, and BMC of academy players suggest that these players are still developing musculoskeletal characteristics. Gradual increases in lean mass and BMC while controlling fat mass is an important consideration for practitioners working with academy rugby league players, especially in the lower body.

Early-onset arthritis in retired National Football League players.

PubMed

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.

Key Issues in Empirically Identifying Chronically Low-Performing and Turnaround Schools

ERIC Educational Resources Information Center

Hansen, Michael

2012-01-01

One of the US Department of Education's key priorities is turning around the nation's persistently low-achieving schools, yet exactly how to identify low-performing schools is a task left to state policy makers, and a myriad of definitions have been utilized. In addition, exactly how to recognize when a school begins to turn around is not well…

Predicting Player Position for Talent Identification in Association Football

NASA Astrophysics Data System (ADS)

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.

Sports injuries in Plus League volleyball players.

PubMed

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

Bioactive nanofibers enable the identification of thrombospondin 2 as a key player in enamel regeneration.

PubMed

Huang, Zhan; Newcomb, Christina J; Lei, Yaping; Zhou, Yan; Bornstein, Paul; Amendt, Brad A; Stupp, Samuel I; Snead, Malcolm L

2015-08-01

Tissue regeneration and development involves highly synchronized signals both between cells and with the extracellular environment. Biomaterials can be tuned to mimic specific biological signals and control cell response(s). As a result, these materials can be used as tools to elucidate cell signaling pathways and candidate molecules involved with cellular processes. In this work, we explore enamel-forming cells, ameloblasts, which have a limited regenerative capacity. By exposing undifferentiated cells to a self-assembling matrix bearing RGDS epitopes, we elicited a regenerative signal at will that subsequently led to the identification of thrombospondin 2 (TSP2), an extracellular matrix protein that has not been previously recognized as a key player in enamel development and regeneration. Targeted disruption of the thrombospondin 2 gene (Thbs2) resulted in enamel formation with a disordered architecture that was highly susceptible to wear compared to their wild-type counterparts. To test the regenerative capacity, we injected the bioactive matrix into the enamel organ and discovered that the enamel organic epithelial cells in TSP-null mice failed to polarize on the surface of the artificial matrix, greatly reducing integrin β1 and Notch1 expression levels, which represent signaling pathways known to be associated with TSP2. These results suggest TSP2 plays an important role in regulating cell-matrix interactions during enamel formation. Exploiting the signaling pathways activated by biomaterials can provide insight into native signaling mechanisms crucial for tooth development and cell-based strategies for enamel regeneration. Copyright © 2015 Elsevier Ltd. All rights reserved.

Is strength-training frequency a key factor to develop performance adaptations in young elite soccer players?

PubMed

Otero-Esquina, Carlos; de Hoyo Lora, Moisés; Gonzalo-Skok, Óliver; Domínguez-Cobo, Sergio; Sánchez, Hugo

2017-11-01

The aim of this study was to analyse the effects of a combined strength-training programme (full-back squat, YoYo TM leg curl, plyometrics and sled towing exercises) on performance in elite young soccer players and to examine the effects when this training programme was performed one or two days per week. Thirty-six male soccer players (U-17 to U-19) were recruited and assigned to experimental groups (EXP1: 1 s w -1 ; EXP2: 2 s w -1 ) or a control group (CON). Performance was assessed through a countermovement jump (CMJ) test (relative peak power [CMJ PP ] and CMJ height [CMJ H ]), a 20-m linear sprint test with split-times at 10-m, and a change of direction test (V-cut test) 1 week before starting the training programme and also 1 week after performing such training programme. Within-group analysis showed substantial improvements in CMJ variables (ES: 0.39-0.81) and COD (ES: 0.70 and 0.76) in EXP1 and EXP2, while EXP2 also showed substantial enhancements in all linear sprinting tests (ES: 0.43-0.52). Between-group analysis showed substantially greater improvements in CMJ variables (ES: 0.39-0.68) in experimental groups in comparison to CON. Furthermore, EXP2 achieved a substantial better performance in 20-m (ES: 0.48-0.64) than EXP1 and CON. Finally, EXP2 also showed greater enhancements in 10-m (ES: 0.50) and V-cut test (ES: 0.52) than EXP1. In conclusion, the combined strength-training programme improved jumping ability, independently of training frequency, though the achievement of two sessions per week also enhanced sprinting abilities (linear and COD) in young soccer players.

Lateral Scapular Slide Test and Scapular Mobility in Volleyball Players

PubMed Central

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

DETERMINATION OF CLINICALLY RELEVANT DIFFERENCES IN FRONTAL PLANE HOP TESTS IN WOMEN'S COLLEGIATE BASKETBALL AND SOCCER PLAYERS

PubMed Central

Hardesty, Kelly; Hegedus, Eric J.; Ford, Kevin R.; Nguyen, Anh‐Dung

2017-01-01

Background ACL injury prevention programs are less successful in female basketball players than in soccer players. Previous authors have identified anthropometric and biomechanical differences between the athletes and different sport‐specific demands, including a higher frequency of frontal plane activities in basketball. Current injury risk screening and preventive training practices do not place a strong emphasis on frontal plane activities. The medial and lateral triple hop for distance tests may be beneficial for use in the basketball population. Hypothesis/Purpose To 1) establish normative values for the medial and lateral triple hop tests in healthy female collegiate athletes, and 2) analyze differences in test scores between female basketball and soccer players. It was hypothesized that due to the frequent frontal plane demands of their sport, basketball players would exhibit greater performance during these frontal plane performance tests. Study Design Cross‐sectional. Methods Thirty‐two NCAA Division‐1 female athletes (20 soccer, 12 basketball) performed three trials each of a medial and lateral triple hop for distance test. Distances were normalized to height and mass in order to account for anthropometric differences. Repeated measures ANOVAs were performed to identify statistically significant main effects of sport (basketball vs. soccer), and side (right vs. left), and sport x side interactions. Results After accounting for anthropometric differences, soccer players exhibited significantly better performance than basketball players in the medial and lateral triple hop tests (p < 0.05). Significant side differences (p = 0.02) were identified in the entire population for the medial triple hop test, such that participants jumped farther on their left (400.3 ± 41.5 cm) than right (387.9 ± 43.4 cm) limbs, but no side differences were identified in the lateral triple hop. No significant side x sport interactions were identified

Biomechanical Differences of Multidirectional Jump Landings Among Female Basketball and Soccer Players.

PubMed

Taylor, Jeffrey B; Ford, Kevin R; Schmitz, Randy J; Ross, Scott E; Ackerman, Terry A; Shultz, Sandra J

2017-11-01

Taylor, JB, Ford, KR, Schmitz, RJ, Ross, SE, Ackerman, TA, and Shultz, SJ. Biomechanical differences of multidirectional jump landings among female basketball and soccer players. J Strength Cond Res 31(11): 3034-3045, 2017-Anterior cruciate ligament (ACL) injury prevention programs are less successful in basketball than soccer and may be due to distinct movement strategies that these athletes develop from sport-specific training. The purpose of this study was to identify biomechanical differences between female basketball and soccer players during multidirectional jump landings. Lower extremity biomechanics of 89 female athletes who played competitive basketball (n = 40) or soccer (n = 49) at the middle- or high-school level were analyzed with 3-dimensional motion analysis during a drop vertical jump, double- (SAG-DL) and single-leg forward jump (SAG-SL), and double- (FRONT-DL) and single-leg (FRONT-SL) lateral jump. Basketball players landed with either less hip or knee, or both hip and knee excursion during all tasks (p ≤ 0.05) except for the SAGSL task, basketball players landed with greater peak hip flexion angles (p = 0.04). The FRONT-SL task elicited the most distinct sport-specific differences, including decreased hip adduction (p < 0.001) angles, increased hip internal rotation (p = 0.003), and increased relative knee external rotation (p = 0.001) excursions in basketball players. In addition, the FRONT-SL task elicited greater forces in knee abduction (p = 0.003) and lesser forces in hip adduction (p = 0.001) and knee external rotation (p < 0.001) in basketball players. Joint energetics were different during the FRONT-DL task, as basketball players exhibited less sagittal plane energy absorption at the hip (p < 0.001) and greater hip (p < 0.001) and knee (p = 0.001) joint stiffness. Sport-specific movement strategies were identified during all jump landing tasks, such that soccer players exhibited a more protective landing strategy than basketball

A survey of deep tissue injury in elite female wheelchair basketball players.

PubMed

Shimizu, Yukiyo; Mutsuzaki, Hirotaka; Tachibana, Kaori; Tsunoda, Kenji; Hotta, Kazushi; Fukaya, Takashi; Ikeda, Eiji; Yamazaki, Masashi; Wadano, Yasuyoshi

2017-01-01

To investigate deep tissue injuries (DTIs) in elite female wheelchair basketball players and identify factors associated with their occurrence. Study participants were 22 female wheelchair basketball players on the Japanese national team. The sacral and bilateral ischial regions of each participant were examined using ultrasonography to detect DTIs. DTIs were found in 15 players (68.2%). DTIs were more frequent in players with a central nervous system disorder (CNSd) (85.7%) than in those with skeletal system disease (SSd) (37.5%, p = 0.020), and in players using a wheelchair in daily life (84.6%) than those using a wheelchair only for basketball (44.4%, p = 0.046). Players with pelvic instability were more likely to have DTIs (90.9% vs. 45.5%, p = 0.017). DTIs were deeper in the ischial region than the sacral region (p = 0.022). Players with CNSd had more DTIs in sacral regions (90% vs. 10%, p = 0.014). Players with DTIs had lower systolic blood pressure (sBP), red blood cell (RBC) count, and serum creatinine levels (sCr) (all p < 0.05). Ischial DTIs were deeper than sacral DTIs. Players with CNSd had more sacral DTIs than those with SSd. CNSd, wheelchair use in daily life, pelvic instability, and lower sBP, RBC, and sCr increased the risk of DTIs.

Visualization of Expert Chat Development in a World of Warcraft Player Group

ERIC Educational Resources Information Center

Chen, Mark

2009-01-01

This article describes expertise development in a player group in the massively multiplayer online game World of Warcraft using visualization of chat log data. Charts were created to get a general sense of chat trends in a specific player group engaged in "high-end raiding", a 40-person collaborative activity. These charts helped identify patterns…

Performance and Return to Sport After Tommy John Surgery Among Major League Baseball Position Players.

PubMed

Jack, Robert A; Burn, Matthew B; Sochacki, Kyle R; McCulloch, Patrick C; Lintner, David M; Harris, Joshua D

2018-06-01

The anterior bundle of the medial ulnar collateral ligament (UCL) is the primary restraint to valgus stress at the elbow and is often injured among overhead throwing athletes. Despite prevention strategies, injuries to the elbow UCL are on the rise. To determine (1) the return-to-sport (RTS) rate of Major League Baseball (MLB) position players after elbow medial UCL reconstruction, (2) postoperative career length and games per season, (3) pre- and postoperative performance, (4) postoperative performance versus matched control players, and (5) whether position players changed positions after UCL reconstruction. Cohort study; Level of evidence, 3. MLB players who underwent elbow UCL reconstruction were identified (cases). Demographic and performance data were collected for each player. Matched controls were identified. RTS in MLB was defined as playing in at least 1 MLB game after UCL reconstruction. Comparisons between case and control groups and pre- and postoperative time points were made via paired samples Student t tests. Thirty-three players (34 surgical procedures) were identified with a mean ± SD age of 30.2 ± 4.2 years and a mean experience in the MLB of 6.3 ± 3.9 years at the time of surgery. Twenty-eight players (84.8%) were able to RTS in MLB at a mean 336.9 ± 121.8 days. However, players ≥30 years old demonstrated a significantly lower RTS rate (53.3%) than players <30 years old (89.4%; P < .05). Catchers had a significantly shorter postoperative career length (2.8 ± 1.8 years) versus matched controls (6.1 ± 1.9 years; P < .05). Outfielders had a significantly lower wins above replacement postoperatively (0.8 ± 0.7) versus preoperatively (1.5 ± 1.1; P < .05). There were no performance differences between cases and matched controls. Twelve players (48%) returned to a different position postoperatively. The RTS rate for MLB position players after elbow UCL reconstruction is similar to that of pitchers. Catchers had a significantly shorter career

Incidence of Elbow Ulnar Collateral Ligament Surgery in Collegiate Baseball Players

PubMed Central

Rothermich, Marcus A.; Conte, Stan A.; Aune, Kyle T.; Fleisig, Glenn S.; Cain, E. Lyle; Dugas, Jeffrey R.

2018-01-01

.1/100 player-seasons, respectively). Nearly half of surgeries (48.5%) were performed during the baseball season. Conclusion: The incidence of UCL surgeries in NCAA Division I collegiate baseball players represents substantial morbidity to this young athletic population. Risk factors for injuries requiring surgery include being a pitcher and an underclassman. Awareness of these factors should be considered in injury prevention programs. Furthermore, this initial study can serve as a foundation for tracking these surgical injuries in future years and then identifying trends over time. PMID:29687011

Incidence of Elbow Ulnar Collateral Ligament Surgery in Collegiate Baseball Players.

PubMed

Rothermich, Marcus A; Conte, Stan A; Aune, Kyle T; Fleisig, Glenn S; Cain, E Lyle; Dugas, Jeffrey R

2018-04-01

surgeries (48.5%) were performed during the baseball season. The incidence of UCL surgeries in NCAA Division I collegiate baseball players represents substantial morbidity to this young athletic population. Risk factors for injuries requiring surgery include being a pitcher and an underclassman. Awareness of these factors should be considered in injury prevention programs. Furthermore, this initial study can serve as a foundation for tracking these surgical injuries in future years and then identifying trends over time.

The relative age effect in youth soccer players from Spain.

PubMed

Gutierrez Diaz Del Campo, David; Pastor Vicedo, Juan Carlos; Gonzalez Villora, Sixto; Contreras Jordan, Onofre Ricardo

2010-01-01

The purpose of this study was to identify the existence of Relative Age Effect (RAE) at youth level in both elite and amateur Spanish soccer clubs, and also to carry out an analysis providing with information on how this effect has evolved in recent years. We have obtained information on the youth teams of the 20 clubs belonging to the Spanish Professional Football League (LFP) in two separate seasons (2005-2006 and 2008-2009) as well as data on five youth academies belonging to amateur clubs. The collected data revealed an over- representation of players born in the first months of the selection year in all groups of analysis (Elite 2005-2006, Elite 2008-2009 and Amateurs), although only the Elite groups showed significant variations in birth-date distribution in relation to the Spanish population. The results showed a reduction in RAE from the 2005-2006 season to the 2008-2009 season. The following variables - playing position, the number of years each player has spent in their specific age group and the category of the team at each club were shown not to have influence on the extent of RAE. Key pointsThere was RAE in all groups analyzed, although only the Elite groups showed significant variations in birth-date distribution in relation to the general population.RAE is more evident in the Elite groups than in the Amateur probably because of the detection process, which is more thorough in the Elite groups.Playing position, number of years in their specific age group and category of the team did not have any influence on the extent of RAE.Any attempts to prevent RAE should be based on a stable sport policy and the implication of all the stakeholders in the system. All of them should think in the development of a player as a long-term project.

ENCoRE: an efficient software for CRISPR screens identifies new players in extrinsic apoptosis.

PubMed

Trümbach, Dietrich; Pfeiffer, Susanne; Poppe, Manuel; Scherb, Hagen; Doll, Sebastian; Wurst, Wolfgang; Schick, Joel A

2017-11-25

As CRISPR/Cas9 mediated screens with pooled guide libraries in somatic cells become increasingly established, an unmet need for rapid and accurate companion informatics tools has emerged. We have developed a lightweight and efficient software to easily manipulate large raw next generation sequencing datasets derived from such screens into informative relational context with graphical support. The advantages of the software entitled ENCoRE (Easy NGS-to-Gene CRISPR REsults) include a simple graphical workflow, platform independence, local and fast multithreaded processing, data pre-processing and gene mapping with custom library import. We demonstrate the capabilities of ENCoRE to interrogate results from a pooled CRISPR cellular viability screen following Tumor Necrosis Factor-alpha challenge. The results not only identified stereotypical players in extrinsic apoptotic signaling but two as yet uncharacterized members of the extrinsic apoptotic cascade, Smg7 and Ces2a. We further validated and characterized cell lines containing mutations in these genes against a panel of cell death stimuli and involvement in p53 signaling. In summary, this software enables bench scientists with sensitive data or without access to informatic cores to rapidly interpret results from large scale experiments resulting from pooled CRISPR/Cas9 library screens.

The King-Devick (K-D) test and concussion diagnosis in semi-professional rugby union players.

PubMed

Molloy, John H; Murphy, Ian; Gissane, Conor

2017-08-01

To determine the utility of the King-Devick (K-D) test in identifying sports-related concussion in semi-professional rugby players. Descriptive cohort study. 176 male players were recruited from a semi-professional rugby union competition in New Zealand (NZ). Baseline K-D scores were obtained in the pre-season. Post-match K-D and Pitch Side Concussion Assessment Version 2 (PSCA2) scores were obtained in those with suspected concussion. Post-match K-D scores were also administered to selected control players. 19 concussions in 18 players were analysed. In addition, 33 controls were used for analysis. A positive K-D test was identified in 53% of players with concussion post-match. Conversely, a positive test was identified in 33% of controls. The sensitivity and specificity of the K-D test was calculated as 53% and 69% respectively. The positive predictive value and negative predictive value was 48% and 73% respectively. The PSCA2 correctly identified 74% of concussions. The K-D test identified 3 cases not identified by the PSCA2. When the PSCA2 and K-D were combined, 89% of concussions were correctly identified. The K-D test does not appear to be effective if used as a stand-alone test for the diagnosis of concussion. However, if used alongside current side-line cognitive and balance tests, it may assist in more accurately diagnosing sports-related concussion. Further research should look to utilise the K-D test in in-match protocols to establish if this improves the diagnostic accuracy of in-match protocols for sports-related concussion. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

The movement characteristics of English Premiership rugby union players.

PubMed

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 < 0.05) absolute and relative distances than the forwards. The 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.

Integrated RNA-Seq and sRNA-Seq Analysis Identifies Chilling and Freezing Responsive Key Molecular Players and Pathways in Tea Plant (Camellia sinensis)

PubMed Central

Zheng, Chao; Zhao, Lei; Wang, Yu; Shen, Jiazhi; Zhang, Yinfei; Jia, Sisi; Li, Yusheng; Ding, Zhaotang

2015-01-01

Tea [Camellia sinensis (L) O. Kuntze, Theaceae] is one of the most popular non-alcoholic beverages worldwide. Cold stress is one of the most severe abiotic stresses that limit tea plants’ growth, survival and geographical distribution. However, the genetic regulatory network and signaling pathways involved in cold stress responses in tea plants remain unearthed. Using RNA-Seq, DGE and sRNA-Seq technologies, we performed an integrative analysis of miRNA and mRNA expression profiling and their regulatory network of tea plants under chilling (4℃) and freezing (-5℃) stress. Differentially expressed (DE) miRNA and mRNA profiles were obtained based on fold change analysis, miRNAs and target mRNAs were found to show both coherent and incoherent relationships in the regulatory network. Furthermore, we compared several key pathways (e.g., ‘Photosynthesis’), GO terms (e.g., ‘response to karrikin’) and transcriptional factors (TFs, e.g., DREB1b/CBF1) which were identified as involved in the early chilling and/or freezing response of tea plants. Intriguingly, we found that karrikins, a new group of plant growth regulators, and β-primeverosidase (BPR), a key enzyme functionally relevant with the formation of tea aroma might play an important role in both early chilling and freezing response of tea plants. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis further confirmed the results from RNA-Seq and sRNA-Seq analysis. This is the first study to simultaneously profile the expression patterns of both miRNAs and mRNAs on a genome-wide scale to elucidate the molecular mechanisms of early responses of tea plants to cold stress. In addition to gaining a deeper insight into the cold resistant characteristics of tea plants, we provide a good case study to analyse mRNA/miRNA expression and profiling of non-model plant species using next-generation sequencing technology. PMID:25901577

Concussion Knowledge in High School Football Players

PubMed Central

Cournoyer, Janie; Tripp, Brady L.

2014-01-01

Context: 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. Objective: To survey high school varsity football players to determine their level of knowledge about concussions after the initiation of new concussion-education legislation. Design: Cross-sectional study. Setting: Descriptive survey administered in person during a team meeting. Patients or Other Participants: A total of 334 varsity football players from 11 high schools in Florida. Main Outcome Measure(s): 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. Results: 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. Conclusions: 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

Concussion knowledge in high school football players.

PubMed

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.

Making intelligent systems team players: Overview for designers

NASA Technical Reports Server (NTRS)

Malin, Jane T.; Schreckenghost, Debra L.

1992-01-01

This report is a guide and companion to the NASA Technical Memorandum 104738, 'Making Intelligent Systems Team Players,' Volumes 1 and 2. The first two volumes of this Technical Memorandum provide comprehensive guidance to designers of intelligent systems for real-time fault management of space systems, with the objective of achieving more effective human interaction. This report provides an analysis of the material discussed in the Technical Memorandum. It clarifies what it means for an intelligent system to be a team player, and how such systems are designed. It identifies significant intelligent system design problems and their impacts on reliability and usability. Where common design practice is not effective in solving these problems, we make recommendations for these situations. In this report, we summarize the main points in the Technical Memorandum and identify where to look for further information.

Physical fitness of elite Belgian soccer players by player position.

PubMed

Boone, Jan; Vaeyens, Roel; Steyaert, Adelheid; Vanden Bossche, Luc; Bourgois, Jan

2012-08-01

The purpose of this study was to gain an insight into the physical and physiological profile of elite Belgian soccer players with specific regard to the player's position on the field. The sample consisted of 289 adult players from 6 different first division teams. The players were divided into 5 subgroups (goalkeepers, center backs, full backs, midfielders, and strikers) according to their self-reported best position on the field. The subjects performed anaerobic (10-m sprint, 5 × 10-m shuttle run [SR], squat jump [SJ], and countermovement jump [CMJ]) and aerobic (incremental running protocol) laboratory tests. The strikers had significantly shorter sprinting times (5-, 5- to 10-m time, and SR) compared with the midfielders, center backs, and goalkeepers, whereas the full backs were also significantly faster compared with the goalkeepers and the center backs. The goalkeepers and the center backs displayed higher jumping heights (total mean SJ = 40.7 ± 4.6 cm and CMJ = 43.1 ± 4.9 cm) compared with the other 3 positions, whereas the strikers also jumped higher than the full backs and the midfielders did. Regarding the aerobic performance, both full backs and the midfielders (61.2 ± 2.7 and 60.4 ± 2.8 ml · min(-1) · kg(-1), respectively) had a higher VO2max compared with the strikers, center backs, and goalkeepers (56.8 ± 3.1, 55.6 ± 3.5, and 52.1 ± 5.0 ml · min(-1) · kg(-1), respectively). From this study, it could be concluded that players in different positions have different physiological characteristics. The results of this study might provide useful insights for individualized conditional training programs for soccer players. Aside from the predominant technical and tactical skills, a physical profile that is well adjusted to the position on the field might enhance game performance.

Player guild dynamics and evolution in massively multiplayer online games.

PubMed

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.

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

PubMed Central

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. PMID:28352493

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

PubMed

Kuriyama, Andrew M; Nakatsuka, Austin S; Yamamoto, Loren G

2017-03-01

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.

Epidemiology and Impact on Performance of Lower Extremity Stress Injuries in Professional Basketball Players.

PubMed

Khan, Moin; Madden, Kim; Burrus, M Tyrrell; Rogowski, Joseph P; Stotts, Jeff; Samani, Marisa J; Sikka, Robby; Bedi, Asheesh

Professional basketball players in the National Basketball Association (NBA) subject their lower extremities to significant repetitive loading during both regular-season and off-season training. Little is known about the incidence of lower extremity bony stress injuries and their impact on return to play and performance in these athletes. Stress injuries of the lower extremity will have significant impact on performance. Case series. Level 4. All bony stress injuries from 2005 to 2015 were identified from the NBA. Number of games missed due to injury and performance statistics were collected from 2 years prior to injury to 2 years after the injury. A linear regression analysis was performed to determine the impact of injury for players who returned to sport. A total of 76 lower extremity bony stress injuries involving 75 NBA players (mean age, 25.4 ± 4.1 years) were identified. Fifty-five percent (42/76) involved the foot, and most injuries occurred during the regular season (82.9%, 63/76), with half occurring within the first 6 weeks. Among players who sustained a fifth metatarsal stress fracture, 42.9% were unable to return to professional play. Players who sustained stress injuries had reduced play performance, specifically related to number of games played ( P = 0.014) and number of steals per game ( P = 0.004). Players who had surgery had significantly better performance at 2 years than those who were managed nonoperatively, independent of the type of injury (β = 4.561; 95% CI, 1.255-7.868). Lower extremity bony stress injuries may significantly affect both short- and long-term player performance and career length. Stress injuries result in decreased player performance, and surgical intervention results in improved performance metrics compared with those treated using conservative methods. Stress injuries result in decreased player performance, and surgical intervention results in improved performance metrics.

THORACOLUMBAR RANGE OF MOTION IN BASEBALL PITCHERS AND POSITION PLAYERS

PubMed Central

Lynall, Robert; Williams, Jeffrey G.; Wong, Regan; Onuki, Takashi; Meister, Keith

2013-01-01

Introduction/Background: Optimal baseball throwing mechanics require a significant contribution of thoracolumbar motion, particularly in the sagittal and transverse planes. This motion is key for proper transmission of forces from the lower to upper extremity, thereby minimizing a throwing athlete's risk of injury and maximizing athletic performance. Purpose: To define the active‐assisted thoracolumbar ROM of both baseball pitchers and position players and to compare these motions both within and between groups. Methods: Fifty‐six asymptomatic, collegiate and minor league baseball pitchers and 42 position players volunteered to participate. Active‐assisted thoracolumbar flexion, extension, and bilateral rotation ROM, were measured in a standing position, using two bubble inclinometers. Two‐tailed t tests were used to determine differences in ROM between and within the pitchers and position players. Results: The pitchers had significantly more rotation to the non‐throwing arm side as compared to the position players (p = .007, effect size = .61). The pitchers also had more rotation to the non‐throwing arm side as compared to their throwing side (p = .006, effect size = .47). There were no other significant differences between the pitchers and the position players (p > .53). Furthermore, the position players did not have a side‐to‐side rotation difference (p = .99). Conclusions: Pitchers have a greater amount of rotation ROM towards the non‐throwing arm side as compared to position players. Pitchers also have a greater amount of rotation ROM to the non‐throwing arm side as compared to their throwing side rotation. Because pitchers often present with posterior shoulder tightness and subsequent altered shoulder horizontal adduction and internal rotation ROM, the increase in non‐throwing side rotation ROM may occur in response to these adaptations. More specifically, this increase in non‐throwing side trunk rotation ROM may allow such athletes to

Sports teams as complex adaptive systems: manipulating player numbers shapes behaviours during football small-sided games.

PubMed

Silva, Pedro; Vilar, Luís; Davids, Keith; Araújo, Duarte; Garganta, Júlio

2016-01-01

Small-sided and conditioned games (SSCGs) in sport have been modelled as complex adaptive systems. Research has shown that the relative space per player (RSP) formulated in SSCGs can impact on emergent tactical behaviours. In this study we adopted a systems orientation to analyse how different RSP values, obtained through manipulations of player numbers, influenced four measures of interpersonal coordination observed during performance in SSCGs. For this purpose we calculated positional data (GPS 15 Hz) from ten U-15 football players performing in three SSCGs varying in player numbers (3v3, 4v4 and 5v5). Key measures of SSCG system behaviours included values of (1) players' dispersion, (2) teams' separateness, (3) coupling strength and time delays between participants' emerging movements, respectively. Results showed that values of participants' dispersion increased, but the teams' separateness remained identical across treatments. Coupling strength and time delay also showed consistent values across SSCGs. These results exemplified how complex adaptive systems, like football teams, can harness inherent degeneracy to maintain similar team spatial-temporal relations with opponents through changes in inter-individual coordination modes (i.e., players' dispersion). The results imply that different team behaviours might emerge at different ratios of field dimension/player numbers. Therefore, sport pedagogists should carefully evaluate the effects of changing RSP in SSCGs as a way of promoting increased or decreased pressure on players.

On-field performance of national football league players after return from concussion.

PubMed

Kumar, Neil S; Chin, Matthew; O'Neill, Craig; Jakoi, Andre M; Tabb, Loni; Wolf, Michael

2014-09-01

There are few data examining the short-term effects of concussions on player performance upon return to play. This study examined changes in on-field performance and the influence of epidemiologic factors on performance and return to play. On-field performance is different in players who return within 7 days after concussion compared with players who miss at least 1 game. Case-control study; Level of evidence, 3. Players in the National Football League who were active during the 2008 to 2012 seasons were considered for inclusion. Weekly injury reports identified concussed players. All players played in at least 4 games before and after the game of injury (sentinel game) within the year of injury (sentinel year). Players who had missed games secondary to another injury or had sustained a second concussion within the sentinel year were excluded. The players' league profiles were used to determine age, position, body mass index, career experience, and games missed. ProFootballFocus performance scores determined player ratings. Statistical analysis used 2-sided t tests and both univariate and multivariate logistic regression models. There were a total of 131 concussions in the 124 players who qualified for this study; 55% of these players missed no games. Defensive secondary, wide receiver, and offensive line were the most commonly affected positions. Players who missed at least 1 game were younger and less experienced. Preinjury ProFootballFocus performance scores were similar to postinjury performance in players without games missed (0.16 vs 0.33; P = .129) and players who missed at least 1 game (-0.06 vs 0.10; P = .219). Age, body mass index, experience, and previous concussion did not correlate with changes in postinjury scores (P > .05). Older, more experienced players and players with late-season concussions were more likely to return to play without missing games (P < .05). The odds of returning within 7 days increased by 18% for each career year and by 40% for

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

PubMed Central

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 <.001) than in players who wore a generic mouth guard. The rate of SRC was also higher (HR = 1.96 [95% CI, 1.40–2.73], P <.001) in players who had sustained an SRC within the previous 12 months (15.1% of the 259 players [95% CI, 11.0%–20.1%]) than in players without a previous SRC (8.2% of the 2028 players [95% CI, 7.1%–9.5%]). Conclusion Incidence of SRC was similar

Prevalence of Os Styloideum in National Hockey League Players

PubMed Central

Greditzer, Harry G.; Hutchinson, Ian D.; Geannette, Christian S.; Hotchkiss, Robert N.; Kelly, Bryan T.; Potter, Hollis G.

2017-01-01

Background: Os styloideum describes an accessory carpal ossicle between the trapezoid, the capitate, and the second and third metacarpals. Injuries to this tissue have been described as part of the carpal boss syndrome. While the etiology of os styloideum remains uncertain, it may represent a physiologic response to altered loading forces in the wrist, similar to the development of cam-type deformity in the hips of ice hockey players or the Bennett lesion in the shoulders of baseball pitchers. Hypothesis: Professional hockey players will have a higher prevalence of os styloideum compared with the general population. Study Design: Case series. Level of Evidence: Level 4. Methods: A retrospective review of 16 professional hockey players from 4 different National Hockey League (NHL) teams who underwent unilateral imaging of the wrist was performed. Seventeen wrists were reviewed for the presence of os styloideum. Results: Thirteen of 16 players (81%) had an os styloideum, representing an increased prevalence compared with the general population. Previous clinical and cadaveric studies estimated a general prevalence of up to 19% (P < 0.001). For the 10 players who had their leading wrist scanned, 9 had an os styloideum (90%). Ten of 11 (91%) players demonstrated a bone marrow edema pattern within the metacarpal and the os styloideum on magnetic resonance imaging. There was no significant association between the presence of an os styloideum and the player’s position, leading wrist, or years in the league. Conclusion: There appears to be an increased prevalence of os styloideum among NHL players, and team physicians should consider this finding while formulating a differential diagnosis for dorsal wrist pain. Clinical Relevance: This study identified NHL players as having an increased prevalence of os styloideum compared with the general population. By doing so, these findings represent an opportunity to enhance our understanding of the etiology, clinical significance

One-Year Prospective Study on Passion and Gambling Problems in Poker Players.

PubMed

Morvannou, Adèle; Dufour, Magali; Brunelle, Natacha; Berbiche, Djamal; Roy, Élise

2018-06-01

The concept of passion is relevant to understanding gambling behaviours and gambling problems. Longitudinal studies are useful to better understand the absence and development of gambling problems; however, only one study has specifically considered poker players. Using a longitudinal design, this study aims to determine the influence, 1 year later, of two forms of passion-harmonious and obsessive-on gambling problems in poker players. A total of 116 poker players was recruited from across Quebec, Canada. The outcome variable of interest was participants' category on the Canadian Pathological Gambling Index, and the predictive variable was the Gambling Passion Scale. Multiple logistic regression analyses were conducted to identify independent risk factors of at-risk poker players 1 year later. Obsessive passion at baseline doubled the risk of gambling problems 1 year later (p < 0.01); for harmonious passion, there was no association. Number of gambling activities, drug problems, and impulsivity were also associated with at-risk gambling. This study highlights the links between obsessive passion and at-risk behaviours among poker players. It is therefore important to prevent the development of obsessive passion among poker players.

World cup soccer players tend to be born with sun and moon in adjacent zodiacal signs

PubMed Central

Verhulst, J

2000-01-01

The ecliptic elongation of the moon with respect to the sun does not show uniform distribution on the birth dates of the 704 soccer players selected for the 1998 World Cup. However, a uniform distribution is expected on astronomical grounds. The World Cup players show a very pronounced tendency (p = 0.00001) to be born on days when the sun and moon are in adjacent zodiacal signs. Key Words: soccer; World Cup; astrology; moon PMID:11131239

Ankle Sprain Injuries: A 2-Year Prospective Cohort Study in Female Greek Professional Basketball Players

PubMed Central

Kofotolis, Nikolaos; Kellis, Eleftherios

2007-01-01

Context: Ankle sprains are a common basketball injury. Therefore, examination of risk factors for injury in female professional basketball players is worthwhile. Objective: To examine rates of ankle sprains, associated time missed from participation, and risk factors for injury during 2 consecutive seasons. Design: Prospective cohort study. Setting: Eighteen professional basketball facilities. Patients or Other Participants: We observed 204 players from 18 female professional basketball teams for 2 consecutive seasons during a 2-year period. Main Outcome Measure(s): Using questionnaires, we recorded the incidence of ankle sprains, participation time missed, and mechanisms of injury in games and practice sessions. Potential risk factors, such as age, body mass, height, training experience, and history of ankle sprain, were examined using multivariate logistic regression. Results: Fifty of the 204 participants sustained ankle injuries; injuries included 32 ankle sprains, which translated to an ankle sprain rate of 1.12 per 1000 hours of exposure to injury. The 32 players missed 224.4 training and game sessions and an average of 7.01 sessions per injury. Most injuries occurred in the key area of the basketball court and were the result of contact. Injury rates during games were higher than injury rates during practice sessions. Centers, followed by guards and forwards, had the highest rate of injury. Players who did not wear an external ankle support had an odds ratio of 2.481 for sustaining an ankle sprain. Conclusions: Female professional basketball athletes who did not wear an external ankle support, who played in the key area, or who functioned as centers had a higher risk for ankle sprain than did other players. PMID:18059995

Identifying key performance indicators for nursing and midwifery care using a consensus approach.

PubMed

McCance, Tanya; Telford, Lorna; Wilson, Julie; Macleod, Olive; Dowd, Audrey

2012-04-01

The aim of this study was to gain consensus on key performance indicators that are appropriate and relevant for nursing and midwifery practice in the current policy context. There is continuing demand to demonstrate effectiveness and efficiency in health and social care and to communicate this at boardroom level. Whilst there is substantial literature on the use of clinical indicators and nursing metrics, there is less evidence relating to indicators that reflect the patient experience. A consensus approach was used to identify relevant key performance indicators. A nominal group technique was used comprising two stages: a workshop involving all grades of nursing and midwifery staff in two HSC trusts in Northern Ireland (n = 50); followed by a regional Consensus Conference (n = 80). During the workshop, potential key performance indicators were identified. This was used as the basis for the Consensus Conference, which involved two rounds of consensus. Analysis was based on aggregated scores that were then ranked. Stage one identified 38 potential indicators and stage two prioritised the eight top-ranked indicators as a core set for nursing and midwifery. The relevance and appropriateness of these indicators were confirmed with nurses and midwives working in a range of settings and from the perspective of service users. The eight indicators identified do not conform to the majority of other nursing metrics generally reported in the literature. Furthermore, they are strategically aligned to work on the patient experience and are reflective of the fundamentals of nursing and midwifery practice, with the focus on person-centred care. Nurses and midwives have a significant contribution to make in determining the extent to which these indicators are achieved in practice. Furthermore, measurement of such indicators provides an opportunity to evidence of the unique impact of nursing/midwifery care on the patient experience. © 2011 Blackwell Publishing Ltd.

Posterior tibial slope as a risk factor for anterior cruciate ligament rupture in soccer players.

PubMed

Senişik, Seçkin; Ozgürbüz, Cengizhan; Ergün, Metin; Yüksel, Oğuz; Taskiran, Emin; Işlegen, Cetin; Ertat, Ahmet

2011-01-01

Anterior cruciate ligament (ACL) is the primary stabilizer of the knee. An impairment of any of the dynamic or static stability providing factors can lead to overload on the other factors and ultimately to deterioration of knee stability. This can result in anterior tibial translation and rupture of the ACL. The purpose of this study was to examine the influence of tibial slope on ACL injury risk on soccer players. A total of 64 elite soccer players and 45 sedentary controls were included in this longitudinal and controlled study. The angle between the tibial mid-diaphysis line and the line between the anterior and posterior edges of the medial tibial plateau was measured as the tibial slope via lateral radiographs. Individual player exposure, and injuries sustained by the participants were prospectively recorded. Eleven ACL injuries were documented during the study period. Tibial slope was not different between soccer players and sedentary controls. Tibial slope in the dominant and non-dominant legs was greater for the injured players compared to the uninjured players. The difference reached a significant level only for the dominant legs (p < 0.001). While the tibial slopes of the dominant and non-dominant legs were not different on uninjured players (p > 0.05), a higher tibial slope was observed in dominant legs of injured players (p < 0.05). Higher tibial slope on injured soccer players compared to the uninjured ones supports the idea that the tibial slope degree might be an important risk factor for ACL injury. Key pointsDominant legs' tibial slopes of the injured players were significantly higher compared to the uninjured players (p < 0.001).Higher tibial slope was determined in dominant legs compared to the non-dominant side, for the injured players (p = 0.042). Different tibial slope measures in dominant and non-dominant legs might be the result of different loading and/or adaptation patterns in soccer.

Identifying key genes associated with acute myocardial infarction.

PubMed

Cheng, Ming; An, Shoukuan; Li, Junquan

2017-10-01

This study aimed to identify key genes associated with acute myocardial infarction (AMI) by reanalyzing microarray data. Three gene expression profile datasets GSE66360, GSE34198, and GSE48060 were downloaded from GEO database. After data preprocessing, genes without heterogeneity across different platforms were subjected to differential expression analysis between the AMI group and the control group using metaDE package. P < .05 was used as the cutoff for a differentially expressed gene (DEG). The expression data matrices of DEGs were imported in ReactomeFIViz to construct a gene functional interaction (FI) network. Then, DEGs in each module were subjected to pathway enrichment analysis using DAVID. MiRNAs and transcription factors predicted to regulate target DEGs were identified. Quantitative real-time polymerase chain reaction (RT-PCR) was applied to verify the expression of genes. A total of 913 upregulated genes and 1060 downregulated genes were identified in the AMI group. A FI network consists of 21 modules and DEGs in 12 modules were significantly enriched in pathways. The transcription factor-miRNA-gene network contains 2 transcription factors FOXO3 and MYBL2, and 2 miRNAs hsa-miR-21-5p and hsa-miR-30c-5p. RT-PCR validations showed that expression levels of FOXO3 and MYBL2 were significantly increased in AMI, and expression levels of hsa-miR-21-5p and hsa-miR-30c-5p were obviously decreased in AMI. A total of 41 DEGs, such as SOCS3, VAPA, and COL5A2, are speculated to have roles in the pathogenesis of AMI; 2 transcription factors FOXO3 and MYBL2, and 2 miRNAs hsa-miR-21-5p and hsa-miR-30c-5p may be involved in the regulation of the expression of these DEGs.

Suicide in professional American football players in the past 95 years.

PubMed

Webner, David; Iverson, Grant L

2016-01-01

To examine publicly-available information on all identified cases of suicide in active or former American professional football players between 1920 and the spring of 2015. Retrospective cohort study. Professional American Football in the US. A cohort of 26 702 athletes who had died, retired or were currently playing in the NFL from nfl.com since 1920 was identified. Internet queries identifying 26 professional football players who completed suicide. Obituaries and news reports were reviewed. The primary outcome measures included mortality, demographic characteristics and life circumstances in professional American football players completing suicide. From 1920-2015, the median age of the 26 men who completed suicide was 39.5 years (range = 23-85). The median number of years after retirement was 6.5 (range = 0-63). Most of the deaths since 1920 have occurred in the past 15 years (58.7%) and a large percentage have occurred since 2009 (42.3%). Most of the men suffered from multiple life stressors prior to their deaths, such as retirement from sport, loss of steady income, divorce, failed business ventures, estrangement from family members and medical, psychiatric and/or substance abuse problems. A disproportionate number of completed suicides in current and former professional football players have occurred since 2009 (42.3%). It is well established in the literature that the causes of depression and suicidality are diverse, often multifactorial and treatable. Providing at-risk retired athletes with mental health treatment will likely reduce their suffering and improve their quality-of-life.

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

PubMed Central

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

Performance Outcomes After Hook of Hamate Fractures in Major League Baseball Players.

PubMed

Guss, Michael S; Begly, John P; Ramme, Austin J; Taormina, David P; Rettig, Michael E; Capo, John T

2017-07-17

Major League Baseball (MLB) players are at risk of hook of hamate fractures. There is a paucity of data assessing the effect of a hook of hamate fracture on MLB players' future athletic performance. To determine if MLB players who sustain hook of hamate fractures demonstrate decreased performance upon return to competition when compared with their performance before injury and that of their control-matched peers. Retrospective Case-Control Design. Retrospective Database Study. 18 MLB players who sustained hook of hamate fractures. Data for 18 MLB players with hook of hamate fractures incurred over 26 seasons (1989 to 2014) were obtained from injury reports, press releases, and player profiles ( www.mlb.com and www.baseballreference.com ). Player age, position, number of years in the league, mechanism of injury and treatment were recorded. Individual season statistics for the two seasons immediately prior to injury and the two seasons after injury for the main performance variable - wins above replacement (WAR) were obtained. Eighteen controls matched by player position, age, and performance statistics were identified. A performance comparison of the cohorts was performed. Post-injury performance compared to pre-injury performance and matched-controls. Mean age at the time of injury was 25.1 years with a mean of 4.4 seasons of MLB experience prior to injury. All injuries were sustained to their nondominant batting hand. All players underwent operative intervention. There was no significant change in WAR or ISO when pre-injury and post-injury performance was compared. When compared with matched-controls, no significant decline in performance in WAR the first season and second season after injury was found. MLB players sustaining hook of hamate fractures can reasonably expect to return to their pre-injury performance levels following operative treatment.

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

PubMed

Skinner, Brian; Guy, Stephen J

2015-01-01

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.

Prevalence of radiological findings related to femoroacetabular impingement in professional baseball players in Japan.

PubMed

Fukushima, Kensuke; Takahira, Naonobu; Imai, Sousuke; Yamazaki, Tetsuya; Kenmoku, Tomonori; Uchiyama, Katsufumi; Takaso, Masashi

2016-11-01

Femoroacetabular impingement (FAI) is a known patho-mechanism that causes hip pain and osteoarthritis (OA) and is considered uncommon in Japan, while secondary OA due to hip dysplasia is considered common. However, no studies have specifically targeted athletes in Japan and/or Asia. This study aimed to determine FAI prevalence using radiological findings among baseball players playing on a professional, Japanese team. We retrospectively assessed 63 plain anteroposterior (AP) hip radiographs (126 hips from 47 [74.6%] Asian players and 16 [25.3%] non-Asian players) obtained for medical evaluations. Radiographs were used to measure lateral center-edge (LCE) angle; acetabular roof obliquity (ARO); and the presence of crossover sign (COS), posterior wall sign (PWS), coxa profunda, pistol grip deformity, herniation pits, and labral ossification. Further, the prevalence of radiographic indicators related to FAI was compared between Asian and non-Asian players. In the 126 hips examined, 10 hips (7.94%) were classified as having hip dysplasia (LCE angles < 20°). Of the remaining 116 hips, eight (6.9%) had LCE angles > 40°, and 24 hips (20.7%) had AROs of <0°, indicating acetabular over-coverage. In Asian players, COS was identified in 47 hips (54.0%), positive PWS in 38 hips (43.7%), positive coxa profunda in 8 hips (9.2%), and pistol grip deformity in 37 hips (42.5%). Further, herniation pits and positive labral ossification were identified in 25 (28.7%) and 11 (12.6%) hips, respectively. A comparative review of COS prevalence (Asians vs. non-Asians) revealed that COS was significantly higher in Asian players. No differences were observed in the mean LCE angle, mean ARO, or other radiographic indicators. Radiological indicators related to FAI were identified in 76.6% (72/94 hips) of the Asian professional baseball players; this prevalence was considerably higher than that reported for general Asian populations. We consider that elite Asian athletes may frequently

Identifying risk event in Indonesian fresh meat supply chain

NASA Astrophysics Data System (ADS)

Wahyuni, H. C.; Vanany, I.; Ciptomulyono, U.

2018-04-01

The aim of this paper is to identify risk issues in Indonesian fresh meat supply chain from the farm until to the “plate”. The critical points for food safety in physical fresh meat product flow are also identified. The paper employed one case study in the Indonesian fresh meat company by conducting observations and in-depth three stages of interviews. At the first interview, the players, process, and activities in the fresh meat industry were identified. In the second interview, critical points for food safety were recognized. The risk events in each player and process were identified in the last interview. The research will be conducted in three stages, but this article focuses on risk identification process (first stage) only. The second stage is measuring risk and the third stage focuses on determining the value of risk priority. The results showed that there were four players in the fresh meat supply chain: livestock (source), slaughter (make), distributor and retail (deliver). Each player has different activities and identified 16 risk events in the fresh meat supply chain. Some of the strategies that can be used to reduce the occurrence of such risks include improving the ability of laborers on food safety systems, improving cutting equipment and distribution processes

Identifying Key Drivers of Return Reversal with Dynamical Bayesian Factor Graph

PubMed Central

Zhao, Shuai; Tong, Yunhai; Wang, Zitian; Tan, Shaohua

2016-01-01

In the stock market, return reversal occurs when investors sell overbought stocks and buy oversold stocks, reversing the stocks’ price trends. In this paper, we develop a new method to identify key drivers of return reversal by incorporating a comprehensive set of factors derived from different economic theories into one unified dynamical Bayesian factor graph. We then use the model to depict factor relationships and their dynamics, from which we make some interesting discoveries about the mechanism behind return reversals. Through extensive experiments on the US stock market, we conclude that among the various factors, the liquidity factors consistently emerge as key drivers of return reversal, which is in support of the theory of liquidity effect. Specifically, we find that stocks with high turnover rates or high Amihud illiquidity measures have a greater probability of experiencing return reversals. Apart from the consistent drivers, we find other drivers of return reversal that generally change from year to year, and they serve as important characteristics for evaluating the trends of stock returns. Besides, we also identify some seldom discussed yet enlightening inter-factor relationships, one of which shows that stocks in Finance and Insurance industry are more likely to have high Amihud illiquidity measures in comparison with those in other industries. These conclusions are robust for return reversals under different thresholds. PMID:27893780

Identifying Key Drivers of Return Reversal with Dynamical Bayesian Factor Graph.

PubMed

Zhao, Shuai; Tong, Yunhai; Wang, Zitian; Tan, Shaohua

2016-01-01

In the stock market, return reversal occurs when investors sell overbought stocks and buy oversold stocks, reversing the stocks' price trends. In this paper, we develop a new method to identify key drivers of return reversal by incorporating a comprehensive set of factors derived from different economic theories into one unified dynamical Bayesian factor graph. We then use the model to depict factor relationships and their dynamics, from which we make some interesting discoveries about the mechanism behind return reversals. Through extensive experiments on the US stock market, we conclude that among the various factors, the liquidity factors consistently emerge as key drivers of return reversal, which is in support of the theory of liquidity effect. Specifically, we find that stocks with high turnover rates or high Amihud illiquidity measures have a greater probability of experiencing return reversals. Apart from the consistent drivers, we find other drivers of return reversal that generally change from year to year, and they serve as important characteristics for evaluating the trends of stock returns. Besides, we also identify some seldom discussed yet enlightening inter-factor relationships, one of which shows that stocks in Finance and Insurance industry are more likely to have high Amihud illiquidity measures in comparison with those in other industries. These conclusions are robust for return reversals under different thresholds.

Anthropometric Characteristics of Columbia, South Carolina, Youth Baseball Players and Dixie Youth World Series Players

ERIC Educational Resources Information Center

French, Karen E.; Spurgeon, John H.; Nevett, Michael E.

2007-01-01

The purpose of this study was to compare measures of body size in two samples of youth baseball players with normative data from the United States National Center for Health Statistics (NCHS) growth charts. One sample of youth baseball players participated in a local little league. The second sample of youth baseball players were members of eight…

Risk factors for patellar tendinopathy in basketball and volleyball players: a cross-sectional study.

PubMed

van der Worp, H; van Ark, M; Zwerver, J; van den Akker-Scheek, I

2012-12-01

Patellar tendinopathy (PT) has a multifactorial etiology, and many possible risk factors have been described in the literature. The findings are conflicting, though, and most research has been conducted on elite athletes. The aim of the current study is to determine the risk factors for PT in a large representative sample of basketball and volleyball players. Separate risk factors for men and women, basketball and volleyball players, and athletes with unilateral and bilateral PT were identified. All basketball and volleyball players between ages 18 and 35 from the Dutch Basketball Association and the Dutch Volleyball Association were invited to complete an online questionnaire on knee complaints and risk factors for PT. The logistic regression analyses included 2224 subjects. The risk factors for PT were age, playing at the national level, being male and playing volleyball (compared with playing basketball). The risk factors for men and women were comparable. Among volleyball players, outside hitters and middle blockers/hitters had an increased risk compared with setters. For basketball players, no risk factors could be identified. No differences in the risk factors were found between athletes with unilateral and bilateral PT. These findings should be taken into account for prevention and rehabilitation purposes. © 2011 John Wiley & Sons A/S.

Identifying Key Hospital Service Quality Factors in Online Health Communities

PubMed Central

Jung, Yuchul; Hur, Cinyoung; Jung, Dain

2015-01-01

Background The volume of health-related user-created content, especially hospital-related questions and answers in online health communities, has rapidly increased. Patients and caregivers participate in online community activities to share their experiences, exchange information, and ask about recommended or discredited hospitals. However, there is little research on how to identify hospital service quality automatically from the online communities. In the past, in-depth analysis of hospitals has used random sampling surveys. However, such surveys are becoming impractical owing to the rapidly increasing volume of online data and the diverse analysis requirements of related stakeholders. Objective As a solution for utilizing large-scale health-related information, we propose a novel approach to identify hospital service quality factors and overtime trends automatically from online health communities, especially hospital-related questions and answers. Methods We defined social media–based key quality factors for hospitals. In addition, we developed text mining techniques to detect such factors that frequently occur in online health communities. After detecting these factors that represent qualitative aspects of hospitals, we applied a sentiment analysis to recognize the types of recommendations in messages posted within online health communities. Korea’s two biggest online portals were used to test the effectiveness of detection of social media–based key quality factors for hospitals. Results To evaluate the proposed text mining techniques, we performed manual evaluations on the extraction and classification results, such as hospital name, service quality factors, and recommendation types using a random sample of messages (ie, 5.44% (9450/173,748) of the total messages). Service quality factor detection and hospital name extraction achieved average F1 scores of 91% and 78%, respectively. In terms of recommendation classification, performance (ie, precision) is

Identifying key hospital service quality factors in online health communities.

PubMed

Jung, Yuchul; Hur, Cinyoung; Jung, Dain; Kim, Minki

2015-04-07

The volume of health-related user-created content, especially hospital-related questions and answers in online health communities, has rapidly increased. Patients and caregivers participate in online community activities to share their experiences, exchange information, and ask about recommended or discredited hospitals. However, there is little research on how to identify hospital service quality automatically from the online communities. In the past, in-depth analysis of hospitals has used random sampling surveys. However, such surveys are becoming impractical owing to the rapidly increasing volume of online data and the diverse analysis requirements of related stakeholders. As a solution for utilizing large-scale health-related information, we propose a novel approach to identify hospital service quality factors and overtime trends automatically from online health communities, especially hospital-related questions and answers. We defined social media-based key quality factors for hospitals. In addition, we developed text mining techniques to detect such factors that frequently occur in online health communities. After detecting these factors that represent qualitative aspects of hospitals, we applied a sentiment analysis to recognize the types of recommendations in messages posted within online health communities. Korea's two biggest online portals were used to test the effectiveness of detection of social media-based key quality factors for hospitals. To evaluate the proposed text mining techniques, we performed manual evaluations on the extraction and classification results, such as hospital name, service quality factors, and recommendation types using a random sample of messages (ie, 5.44% (9450/173,748) of the total messages). Service quality factor detection and hospital name extraction achieved average F1 scores of 91% and 78%, respectively. In terms of recommendation classification, performance (ie, precision) is 78% on average. Extraction and

Discriminating Talent Identified Junior Australian Footballers Using a Fundamental Gross Athletic Movement Assessment

PubMed Central

Woods, Carl T.; Banyard, Harry G.; McKeown, Ian; Fransen, Job; Robertson, Sam

2016-01-01

identification approaches in junior AF, as it may provide coaches with insight into a juniors developmental potential. Key points On average, talent identified junior AF players possess superior athletic movement qualities relative to their non-talent identified counterparts. The integration of this gross athletic movement assessment into contemporary multidimensional approaches to talent identification may enable insight into a juniors developmental potential. The athletic qualities underpinning the production of the overhead squat movement could augment functional physical qualities in junior Australian footballers. Assessing movement competency in junior contexts may afford practitioners with the opportunity to rectify inefficient fundamental movement patterns prior to entrance into elite senior ranks. PMID:27803635

Return to Play and Player Performance After Anterior Cruciate Ligament Injury in Elite Australian Rules Football Players

PubMed Central

Liptak, Matthew G.; Angel, Kevin R.

2017-01-01

Background: Australian Rules football is a highly aerobic and anaerobic game that at times requires players to perform cutting or pivoting maneuvers, potentially exposing them to anterior cruciate ligament (ACL) injury. At present, there are limited data available addressing the impact of ACL injury on return to play and preinjury form after ACL reconstruction. Purpose: To determine the prevalence of ACL injury and the incidence of further ACL injury, and to consider player return to play and return to preinjury form after ACL reconstruction. It was hypothesized that elite-level Australian Football League (AFL) players do not return to preinjury form until, at minimum, 2 years after returning to play. Study Design: Case series; Level of evidence, 4. Methods: A retrospective analysis was undertaken on a cohort of elite AFL players who injured their ACL between 1990 and 2000. Return to play after ACL reconstruction was determined by the mean number of ball disposals, or release of the ball by the hand or foot, at 1, 2, and 3 years after return to play and compared with preinjury form. Associations between player and injury characteristics, method of reconstruction, and outcomes (return to play, preinjury form, and further ACL injury) were examined. Results: During the included seasons, a total of 2723 AFL players were listed. Of these, 131 (4.8%) sustained an ACL injury, with 115 players eligible for inclusion. Of 115 players, 26% did not return to elite competition, while 28% of those who did return experienced further ACL injury. The adjusted mean number of disposals (± standard error of the mean) was significantly lower at 1 year (12.21 ± 0.63; P = .003), 2 years (12.09 ± 0.65; P = .008), and 3 years (11.78 ± 0.77; P = .01) after return to play compared with preinjury (14.23 ± 0.67). On average, players did not return to preinjury form by 3 years (P < .01). Players aged 30 years or older were less likely to return to play compared with younger players (P

Respiratory function in wind instrument players.

PubMed

Zuskin, Eugenija; Mustajbegovic, Jadranka; Schachter, E N; Kern, Josipa; Vitale, Ksenija; Pucarin-Cvetkovic, Jasna; Chiarelli, A; Milosevic, M; Jelinic, Jagoda Doko

2009-01-01

The playing of wind instruments has been associated with changes in respiratory function. To investigate the effect of playing wind instruments on lung function and respiratory symptoms. The present study included 99 wind instrument players and a group of 41 string instrument players as a control from 3 major orchestras in Zagreb, Croatia. Data on chronic respiratory symptoms were recorded in all studied subjects. Lung function was measured in wind instrument players by recording maximum expiratory flow-volume curves. Wind instrument players demonstrated significantly higher prevalences of sinusitis, nasal catarrh and hoarseness compared to control musicians. One wind instrument player developed asthma associated with his work. Odds ratios for wind instrument players were significant for chronic cough, chronic phlegm and chronic bronchitis by smoking habit (p<0.05 or p<0.01) but not for length of employment. Ventilatory capacity data indicate that wind instrument players had significantly greater FEV1 (smokers and nonsmokers) as well as FEF50 (nonsmokers) (p<0.05) compared to predicted values. Regression analysis of pulmonary function tests in wind instrument players demonstrate a significant link between FEV1 and FEF50 and length of employment. Those wind instrument players with longer employment had the greatest increases in lung function. Our data suggest that musicians playing wind instruments may be susceptible to chronic upper airway symptoms. Interestingly wind instrument playing may be associated with higher than expected lung function parameters.

Musculoskeletal injuries among Malaysian badminton players.

PubMed

Shariff, A H; George, J; Ramlan, A A

2009-11-01

The purpose of this study was to investigate the pattern of musculoskeletal injuries sustained by Malaysian badminton players. This is a retrospective case notes review of all badminton players who attended the National Sports Institute (NSI) Clinic, Kuala Lumpur, Malaysia, and were diagnosed with musculoskeletal injuries. In a two and a half year period, from January 2005 to June 2007, 469 musculoskeletal injuries were diagnosed among badminton players at the NSI Clinic. The mean age of the players who attended the clinic was 19.2 (range 13-52) years. Approximately 60 percent of the injuries occurred in players younger than 20 years of age. The majority of injuries (91.5 percent) were categorised as mild overuse injury and mostly involved the knee. The majority of the injuries sustained by badminton players in this study were due to overuse, primarily in the knee. The majority of the injuries were diagnosed in younger players and occurred during training/practice sessions. There was no difference in terms of incidence and types of injuries between the genders.

Injuries of the obturator muscles in professional soccer players.

PubMed

Wong-On, Manuel; Turmo-Garuz, Antonio; Arriaza, Rafael; Gonzalez de Suso, Jose Manuel; Til-Perez, Luis; Yanguas-Leite, Xavier; Diaz-Cueli, David; Gasol-Santa, Xavier

2017-02-10

Obturator externus and internus muscular tears are uncommon injuries. Only a few case reports exist, mainly in high-level athletes. Our aim is to describe a series of obturator externus and internus muscular tears in professional soccer players. Injury data from four teams from the First Division of the Spanish Soccer League were collected over a total of four seasons. Any soccer player who sustained an injury to either the obturator externus or internus identified on magnetic resonance (MRI) was included. All injured players were treated non-operatively with a goal of returning to play as fast as possible. Sixteen players sustained injuries to the obturator externus and internus during matches or training sessions. The main complaint was anterior hip pain with a physical examination showing pain during internal rotation or external rotation of the flexed hip. The MRI documented 12 muscular tears of the obturator externus, and 4 muscular tears of the obturator internus. All injuries were treated conservatively based on physical therapy, analgesic medications, and underwent a symptoms-based rehabilitation protocol. Mean return to play was 11.5  ±  8.8 days. Although uncommon, tears of the obturator externus and internus occur in professional soccer players. The MRI scan was essential to the location, classification, and evaluation of the injury size. The clinical relevance of our investigation is based on the relatively benign prognosis of these injuries. IV.

Performance and Return to Sport After Sports Hernia Surgery in NFL Players

PubMed Central

Jack, Robert A.; Evans, David C.; Echo, Anthony; McCulloch, Patrick C.; Lintner, David M.; Varner, Kevin E.; Harris, Joshua D.

2017-01-01

Background: Recognition, diagnosis, and treatment of athletic pubalgia (AP), also known as sports hernia, once underrecognized and undertreated in professional football, are becoming more common. Surgery as the final treatment for sports hernia when nonsurgical treatment fails remains controversial. Given the money involved and popularity of the National Football League (NFL), it is important to understand surgical outcomes in this patient population. Hypothesis: After AP surgery, players would: (1) return to sport (RTS) at a greater than 90% rate, (2) play fewer games for fewer years than matched controls, (3) have no difference in performance compared with before AP surgery, and (4) have no difference in performance versus matched controls. Study Design: Cohort study; Level of evidence, 3. Methods: Internet-based injury reports identified players who underwent AP surgery from January 1996 to August 2015. Demographic and performance data were collected for each player. A 1:1 matched control group and an index year analog were identified. Control and case performance scores were calculated using a standardized scoring system. Groups were compared using paired Student t tests. Results: Fifty-six NFL players (57 AP surgeries) were analyzed (mean age, 28.2 ± 3.1 years; mean years in NFL at surgery, 5.4 ± 3.2). Fifty-three players were able to RTS. Controls were in the NFL longer (P < .05) than players who underwent AP surgery (3.8 ± 2.4 vs 3.2 ± 2.1 years). Controls played more games per season (P < .05) than post-AP players (14.0 ± 2.3 vs 12.0 ± 3.4 games per season). There was no significant (P > .05) difference in pre- versus post-AP surgery performance scores and no significant (P > .05) difference in postoperative performance scores versus controls post-index. Conclusion: There was a high RTS rate after AP surgery without a significant difference in postoperative performance, though career length and games per season after AP surgery were significantly less

Performance and Return to Sport After Sports Hernia Surgery in NFL Players.

PubMed

Jack, Robert A; Evans, David C; Echo, Anthony; McCulloch, Patrick C; Lintner, David M; Varner, Kevin E; Harris, Joshua D

2017-04-01

Recognition, diagnosis, and treatment of athletic pubalgia (AP), also known as sports hernia, once underrecognized and undertreated in professional football, are becoming more common. Surgery as the final treatment for sports hernia when nonsurgical treatment fails remains controversial. Given the money involved and popularity of the National Football League (NFL), it is important to understand surgical outcomes in this patient population. After AP surgery, players would: (1) return to sport (RTS) at a greater than 90% rate, (2) play fewer games for fewer years than matched controls, (3) have no difference in performance compared with before AP surgery, and (4) have no difference in performance versus matched controls. Cohort study; Level of evidence, 3. Internet-based injury reports identified players who underwent AP surgery from January 1996 to August 2015. Demographic and performance data were collected for each player. A 1:1 matched control group and an index year analog were identified. Control and case performance scores were calculated using a standardized scoring system. Groups were compared using paired Student t tests. Fifty-six NFL players (57 AP surgeries) were analyzed (mean age, 28.2 ± 3.1 years; mean years in NFL at surgery, 5.4 ± 3.2). Fifty-three players were able to RTS. Controls were in the NFL longer ( P < .05) than players who underwent AP surgery (3.8 ± 2.4 vs 3.2 ± 2.1 years). Controls played more games per season ( P < .05) than post-AP players (14.0 ± 2.3 vs 12.0 ± 3.4 games per season). There was no significant ( P > .05) difference in pre- versus post-AP surgery performance scores and no significant ( P > .05) difference in postoperative performance scores versus controls post-index. There was a high RTS rate after AP surgery without a significant difference in postoperative performance, though career length and games per season after AP surgery were significantly less than that of matched controls.

Speed and agility of 12- and 14-year-old elite male basketball players.

PubMed

Jakovljevic, Sasa T; Karalejic, Milivoje S; Pajic, Zoran B; Macura, Marija M; Erculj, Frane F

2012-09-01

The aims of this study were (a) to identify and compare the speed and agility of 12- and 14-year-old elite male basketball players and (b) to investigate relations between speed and agility for both age groups of basketball players, to help coaches to improve their work. Sixty-four players aged 12 (M = 11.98 years, SD = 0.311) and 54 players aged 14 (M = 14.092 years, SD = 0.275) were tested. Three agility tests: agility t-test, zigzag agility drill, and agility run 4 × 15 m and 3 speed tests: 20-m run, 30-m run, and 50-m run were applied. Fourteen-year-old players achieved significantly better results in all speed and agility tests compared with 12-year-old players. The correlation coefficient (r = 0.81, p = 0.001) showed that 12-year-old players have the same ability in the 30- and 50-m runs. The other correlation coefficient (r = 0.59, p = 0.001) indicated that 20- and 30-m runs had inherently different qualities. The correlation coefficients between agility tests were <0.71, and therefore, each test in this group represents a specific task. In 14-year-old players, the correlation coefficients between the speed test results were <0.71. In contrast, the correlation coefficients between the agility tests were >0.71, which means that all the 3 tests represent the same quality. During the speed training of 12-year-old players, it is advisable to focus on shorter running distances, up to 30 m. During the agility training of the same players, it is useful to apply exercises with various complexities. In speed training of the 14-year-old players, the 30- and 50-m runs should be applied, and agility training should include more specific basketball movements and activities.

Design and interpretation of anthropometric and fitness testing of basketball players.

PubMed

Drinkwater, Eric J; Pyne, David B; McKenna, Michael J

2008-01-01

The volume of literature on fitness testing in court sports such as basketball is considerably less than for field sports or individual sports such as running and cycling. Team sport performance is dependent upon a diverse range of qualities including size, fitness, sport-specific skills, team tactics, and psychological attributes. The game of basketball has evolved to have a high priority on body size and physical fitness by coaches and players. A player's size has a large influence on the position in the team, while the high-intensity, intermittent nature of the physical demands requires players to have a high level of fitness. Basketball coaches and sport scientists often use a battery of sport-specific physical tests to evaluate body size and composition, and aerobic fitness and power. This testing may be used to track changes within athletes over time to evaluate the effectiveness of training programmes or screen players for selection. Sports science research is establishing typical (or 'reference') values for both within-athlete changes and between-athlete differences. Newer statistical approaches such as magnitude-based inferences have emerged that are providing more meaningful interpretation of fitness testing results in the field for coaches and athletes. Careful selection and implementation of tests, and more pertinent interpretation of data, will enhance the value of fitness testing in high-level basketball programmes. This article presents reference values of fitness and body size in basketball players, and identifies practical methods of interpreting changes within players and differences between players beyond the null-hypothesis.

Recurrent seascape units identify key ecological processes along the western Antarctic Peninsula.

PubMed

Bowman, Jeff S; Kavanaugh, Maria T; Doney, Scott C; Ducklow, Hugh W

2018-04-10

The western Antarctic Peninsula (WAP) is a bellwether of global climate change and natural laboratory for identifying interactions between climate and ecosystems. The Palmer Long-Term Ecological Research (LTER) project has collected data on key ecological and environmental processes along the WAP since 1993. To better understand how key ecological parameters are changing across space and time, we developed a novel seascape classification approach based on in situ temperature, salinity, chlorophyll a, nitrate + nitrite, phosphate, and silicate. We anticipate that this approach will be broadly applicable to other geographical areas. Through the application of self-organizing maps (SOMs), we identified eight recurrent seascape units (SUs) in these data. These SUs have strong fidelity to known regional water masses but with an additional layer of biogeochemical detail, allowing us to identify multiple distinct nutrient profiles in several water masses. To identify the temporal and spatial distribution of these SUs, we mapped them across the Palmer LTER sampling grid via objective mapping of the original parameters. Analysis of the abundance and distribution of SUs since 1993 suggests two year types characterized by the partitioning of chlorophyll a into SUs with different spatial characteristics. By developing generalized linear models for correlated, time-lagged external drivers, we conclude that early spring sea ice conditions exert a strong influence on the distribution of chlorophyll a and nutrients along the WAP, but not necessarily the total chlorophyll a inventory. Because the distribution and density of phytoplankton biomass can have an impact on biomass transfer to the upper trophic levels, these results highlight anticipated links between the WAP marine ecosystem and climate. © 2018 John Wiley & Sons Ltd.

Physical Risk Factors for a Medial Elbow Injury in Junior Baseball Players: A Prospective Cohort Study of 353 Players.

PubMed

Sakata, Jun; Nakamura, Emi; Suzukawa, Makoto; Akaike, Atsushi; Shimizu, Kuniaki

2017-01-01

The physical risk factors for a medial elbow injury in junior baseball players are unknown. To identify the risk factors for an initial medial elbow injury in junior baseball players. Case-control study; Level of evidence, 3. Junior baseball players (aged 6-12 years) without a history of elbow pain underwent a clinical assessment, ultrasonography, and physical function measurements before the baseball season started. Bilateral passive range of motion (ROM) of elbow extension and flexion, external rotation (ER) and internal rotation (IR) of the shoulder, and ER and IR of the hip were measured. IR and ER strength of the shoulder and scapular muscles were measured on both sides. The thoracic kyphosis angle was measured with participants in a relaxed standing position. Before these examinations, every participant completed a questionnaire regarding his or her age, sex, total years of baseball played, position in baseball, number of balls thrown, and episodes of pain during throwing. After the initial test session, each participant was followed up for 12 months to assess for the occurrence of a new injury. Multiple regression analysis was used to identify the risk factors for a medial elbow injury. Seventy-eight players (22.1%) sustained a medial elbow injury. Age ≥9 years (odds ratio [OR], 2.708; 95% CI, 1.224-5.990), pitcher position (OR, 2.620; 95% CI, 1.389-4.941), >100 throws per day (OR, 1.936; 95% CI, 1.072-3.497), thoracic kyphosis angle ≥30° (OR, 2.501; 95% CI, 1.381-4.531), and elbow extension deficit ≥5° (OR, 1.973; 95% CI, 1.022-3.809) were significantly associated with a medial elbow injury. The incidence of an initial medial elbow injury was 22.1%. Age, number of throws per day, thoracic kyphosis angle, and elbow extension deficit are newly discovered risk factors related to physical function. Improvement of the posture and early detection of a silent elbow extension deficit may prevent a medial elbow injury.

A matter of definition--key elements identified in a discourse analysis of definitions of palliative care.

PubMed

Pastrana, T; Jünger, S; Ostgathe, C; Elsner, F; Radbruch, L

2008-04-01

For more than 30 years, the term "palliative care" has been used. From the outset, the term has undergone a series of transformations in its definitions and consequently in its tasks and goals. There remains a lack of consensus on a definition. The aim of this article is to analyse the definitions of palliative care in the specialist literature and to identify the key elements of palliative care using discourse analysis: a qualitative methodology. The literature search focused on definitions of the term 'palliative medicine' and 'palliative care' in the World Wide Web and medical reference books in English and German. A total of 37 English and 26 German definitions were identified and analysed. Our study confirmed the lack of a consistent meaning concerning the investigated terms, reflecting on-going discussion about the nature of the field among palliative care practitioners. Several common key elements were identified. Four main categories emerged from the discourse analysis of the definition of palliative care: target groups, structure, tasks and expertise. In addition, the theoretical principles and goals of palliative care were discussed and found to be key elements, with relief and prevention of suffering and improvement of quality of life as main goals. The identified key elements can contribute to the definition of the concept 'palliative care'. Our study confirms the importance of semantic and ethical influences on palliative care that should be considered in future research on semantics in different languages.

Time-motion analysis of goalball players in attacks: differences of the player positions and the throwing techniques.

PubMed

Monezi, Lucas Antônio; Magalhães, Thiago Pinguelli; Morato, Márcio Pereira; Mercadante, Luciano Allegretti; Furtado, Otávio Luis Piva da Cunha; Misuta, Milton Shoiti

2018-03-26

In this study, we aimed to analyse goalball players time-motion variables (distance covered, time spent, maximum and average velocities) in official goalball match attacks, taking into account the attack phases (preparation and throwing), player position (centres and wings) and throwing techniques (frontal, spin and between the legs). A total of 365 attacks were assessed using a video based method (2D) through manual tracking using the Dvideo system. Inferential non-parametric statistics were applied for comparison of preparation vs. throwing phase, wings vs. centres and, among the throwing techniques, frontal, spin and between the legs. Significant differences were found between the attack preparation versus the throwing phase for all player time-motion variables: distance covered, time spent, maximum player velocity and average player velocity. Wing players performed most of the throws (85%) and covered longer distances than centres (1.65 vs 0.31 m). The between the legs and the spin throwing techniques presented greater values for most of the time-motion variables (distance covered, time spent and maximum player velocity) than did the frontal technique in both attack phases. These findings provide important information regarding players' movement patterns during goalball matches that can be used to plan more effective training.

Mechanisms of traumatic shoulder injury in elite rugby players.

PubMed

Crichton, James; Jones, Doug R; Funk, Lennard

2012-06-01

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. 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. 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. 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.

Mechanisms of traumatic shoulder injury in elite rugby players

PubMed Central

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

Shoulder instability in professional football players.

PubMed

Leclere, Lance E; Asnis, Peter D; Griffith, Matthew H; Granito, David; Berkson, Eric M; Gill, Thomas J

2013-09-01

Shoulder instability is a common problem in American football players entering the National Football League (NFL). Treatment options include nonoperative and surgical stabilization. This study evaluated how the method of treatment of pre-NFL shoulder instability affects the rate of recurrence and the time elapsed until recurrence in players on 1 NFL team. Retrospective cohort. Medical records from 1980 to 2008 for 1 NFL team were reviewed. There were 328 players included in the study who started their career on the team and remained on the team for at least 2 years (mean, 3.9 years; range, 2-14 years). The history of instability prior to entering the NFL and the method of treatment were collected. Data on the occurrence of instability while in the NFL were recorded to determine the rate and timing of recurrence. Thirty-one players (9.5%) had a history of instability prior to entering the NFL. Of the 297 players with no history of instability, 39 (13.1%) had a primary event at a mean of 18.4 ± 22.2 months (range, 0-102 months) after joining the team. In the group of players with prior instability treated with surgical stabilization, there was no statistical difference in the rate of recurrence (10.5%) or the timing to the instability episode (mean, 26 months) compared with players with no history of instability. Twelve players had shoulder instability treated nonoperatively prior to the NFL. Five of these players (41.7%) had recurrent instability at a mean of 4.4 ± 7.0 months (range, 0-16 months). The patients treated nonoperatively had a significantly higher rate of recurrence (P = 0.02) and an earlier time of recurrence (P = 0.04). The rate of contralateral instability was 25.8%, occurring at a mean of 8.6 months. Recurrent shoulder instability is more common in NFL players with a history of nonoperative treatment. Surgical stabilization appears to restore the rate and timing of instability to that of players with no prior history of instability.

The Diet Quality of Competitive Adolescent Male Rugby Union Players with Energy Balance Estimated Using Different Physical Activity Coefficients

PubMed Central

Burrows, Tracy; Harries, Simon K.; Williams, Rebecca L.; Lum, Cheryl; Callister, Robin

2016-01-01

Objectives: The aims of the current study were to comprehensively assess the dietary intakes and diet quality of a sample of Australian competitive adolescent rugby union players and compare these intakes with National and Sports Dietitians Association (SDA) Recommendations for adolescent athletes. A secondary aim investigated applying different physical activity level (PAL) coefficients to determine total energy expenditure (TEE) in order to more effectively evaluate the adequacy of energy intakes. Design: Cross-sectional. Methods: Anthropometrics and dietary intakes were assessed in 25 competitive adolescent male rugby union players (14 to 18 years old). Diet was assessed using the validated Australian Eating Survey (AES) food frequency questionnaire and diet quality was assessed through the Australian Recommended Food Score. Results: The median dietary intakes of participants met national recommendations for percent energy (% E) from carbohydrate, protein and total fat, but not carbohydrate intake when evaluated as g/day as proposed in SDA guidelines. Median intakes of fibre and micronutrients including calcium and iron also met national recommendations. Overall diet quality was classified as ‘good’ with a median diet quality score of 34 (out of a possible 73); however, there was a lack of variety within key food groups including carbohydrates and proteins. Non-core food consumption exceeded recommended levels at 38% of the daily total energy intake, with substantial contributions from takeaway foods and sweetened beverages. A PAL coefficient of 1.2–1.4 was found to best balance the energy intakes of these players in their pre-season. Conclusions: Adolescent rugby players met the percent energy recommendations for macronutrients and attained an overall ‘good’ diet quality score. However, it was identified that when compared to specific recommendations for athletes, carbohydrate intakes were below recommendations and these players in their pre

Mechanisms for Triceps Surae Injury in High Performance Front Row Rugby Union Players: A Kinematic Analysis of Scrummaging Drills

PubMed Central

Flavell, Carol A.; Sayers, Mark G. L.; Gordon, Susan J.; Lee, James B.

2013-01-01

The front row of a rugby union scrum consists of three players. The loose head prop, hooker and tight head prop. The objective of this study was to determine if known biomechanical risk factors for triceps surae muscle injury are exhibited in the lower limb of front row players during contested scrummaging. Eleven high performance front row rugby union players were landmarked bilaterally at the posterior superior iliac spine (PSIS), greater trochanter, lateral femoral epicondyle, midline of the calcaneus above the plantar aspect of the heel, midline lower leg 5cm and 20cm proximal to the lateral malleolus, at the axis of subtalar joint, lateral malleolus, and head of the fifth metatarsal. Players were video recorded during a series of 2 on 1 live scrummaging drills. Biomechanical three dimensional analysis identified large angular displacements, and increased peak velocities and accelerations at the ankle joint during attacking scrummaging drill techniques when in the stance phase of gait. This places the triceps surae as increased risk of injury and provides valuable information for training staff regarding injury prevention and scrum training practices for front row players. Key points Front rowers exhibited patterns of single leg weight bearing, in a position of greater ankle plantar flexion and knee extension at toe off during scrummaging, which is a risk position for TS injury. Front rowers also exhibited greater acceleration at the ankle, knee, and hip joints, and greater changes in ankle ROM from toe strike to toe off during attacking scrum drills. These reported accelerations and joint displacements may be risk factors for TS injury, as the ankle is accelerating into plantar flexion at final push off and the muscle is shortening from an elongated state. PMID:24149740

The Diet Quality of Competitive Adolescent Male Rugby Union Players with Energy Balance Estimated Using Different Physical Activity Coefficients.

PubMed

Burrows, Tracy; Harries, Simon K; Williams, Rebecca L; Lum, Cheryl; Callister, Robin

2016-09-07

The aims of the current study were to comprehensively assess the dietary intakes and diet quality of a sample of Australian competitive adolescent rugby union players and compare these intakes with National and Sports Dietitians Association (SDA) Recommendations for adolescent athletes. A secondary aim investigated applying different physical activity level (PAL) coefficients to determine total energy expenditure (TEE) in order to more effectively evaluate the adequacy of energy intakes. Cross-sectional. Anthropometrics and dietary intakes were assessed in 25 competitive adolescent male rugby union players (14 to 18 years old). Diet was assessed using the validated Australian Eating Survey (AES) food frequency questionnaire and diet quality was assessed through the Australian Recommended Food Score. The median dietary intakes of participants met national recommendations for percent energy (% E) from carbohydrate, protein and total fat, but not carbohydrate intake when evaluated as g/day as proposed in SDA guidelines. Median intakes of fibre and micronutrients including calcium and iron also met national recommendations. Overall diet quality was classified as 'good' with a median diet quality score of 34 (out of a possible 73); however, there was a lack of variety within key food groups including carbohydrates and proteins. Non-core food consumption exceeded recommended levels at 38% of the daily total energy intake, with substantial contributions from takeaway foods and sweetened beverages. A PAL coefficient of 1.2-1.4 was found to best balance the energy intakes of these players in their pre-season. Adolescent rugby players met the percent energy recommendations for macronutrients and attained an overall 'good' diet quality score. However, it was identified that when compared to specific recommendations for athletes, carbohydrate intakes were below recommendations and these players in their pre-season reported high consumption of non-core foods, particularly sugar

Mechanisms for triceps surae injury in high performance front row rugby union players: a kinematic analysis of scrummaging drills.

PubMed

Flavell, Carol A; Sayers, Mark G L; Gordon, Susan J; Lee, James B

2013-01-01

The front row of a rugby union scrum consists of three players. The loose head prop, hooker and tight head prop. The objective of this study was to determine if known biomechanical risk factors for triceps surae muscle injury are exhibited in the lower limb of front row players during contested scrummaging. Eleven high performance front row rugby union players were landmarked bilaterally at the posterior superior iliac spine (PSIS), greater trochanter, lateral femoral epicondyle, midline of the calcaneus above the plantar aspect of the heel, midline lower leg 5cm and 20cm proximal to the lateral malleolus, at the axis of subtalar joint, lateral malleolus, and head of the fifth metatarsal. Players were video recorded during a series of 2 on 1 live scrummaging drills. Biomechanical three dimensional analysis identified large angular displacements, and increased peak velocities and accelerations at the ankle joint during attacking scrummaging drill techniques when in the stance phase of gait. This places the triceps surae as increased risk of injury and provides valuable information for training staff regarding injury prevention and scrum training practices for front row players. Key pointsFront rowers exhibited patterns of single leg weight bearing, in a position of greater ankle plantar flexion and knee extension at toe off during scrummaging, which is a risk position for TS injury.Front rowers also exhibited greater acceleration at the ankle, knee, and hip joints, and greater changes in ankle ROM from toe strike to toe off during attacking scrum drills.These reported accelerations and joint displacements may be risk factors for TS injury, as the ankle is accelerating into plantar flexion at final push off and the muscle is shortening from an elongated state.

Performance and Return to Sport After Nonoperative Treatment of Clavicle Fractures in National Football League Players.

PubMed

Jack, Robert A; Sochacki, Kyle R; Navarro, Sergio M; McCulloch, Patrick C; Lintner, David M; Harris, Joshua D

2017-09-01

Clavicle fractures are often seen in contact sports. The purpose of this study was to determine (1) return-to-sport (RTS) rate of National Football League (NFL) players following nonoperative treatment of clavicle fractures, (2) posttreatment career length and games per season, (3) pre- and posttreatment performance, and (4) posttreatment performance compared with control players matched by position, age, years of experience, and performance. Public records were used to identify NFL players who underwent nonoperative treatment of clavicle fractures. Demographic and performance data were collected for each player. Matched controls (position, age, experience, and performance) were identified. Control and case performance scores were calculated using a standardized scoring system. Return to sport was defined as playing a minimum of 1 game after treatment. Comparisons between the 2 groups and pre- and posttreatment time points were made using paired-samples Student's t tests. Thirty players (32 fractures) were analyzed. Two players fractured their contralateral clavicle. Of the players analyzed, 96.9% were able to RTS at a mean of 244.6±119.6 days. Eight players (27.6%) returned within the same season as their injury. Overall 1-year survival rate posttreatment was 93.5%. Players with nonoperative treatment had career lengths similar to those of controls (P>.05). No significant (P>.05) differences existed in demographic, performance, or games per season data between position groups for cases and matched controls pretreatment and preindex and in posttreatment compared with pretreatment performance scores. Wide receivers played fewer games per season (P=.043) following treatment. No position group had significantly worse posttreatment performance scores when compared with postindex matched controls. [Orthopedics. 2017; 40(5):e836-e843.]. Copyright 2017, SLACK Incorporated.

Vitamin D Deficiency Among Professional Basketball Players.

PubMed

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 (<20 ng/mL), insufficient (20-32 ng/mL), and sufficient (>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

H:q ratios and bilateral leg strength in college field and court sports players.

PubMed

Cheung, Roy T H; Smith, Andrew W; Wong, Del P

2012-06-01

One of the key components in sports injury prevention is the identification of imbalances in leg muscle strength. However, different leg muscle characteristics may occur in large playing area (field) sports and small playing area (court) sports, which should be considered in regular injury prevention assessment. This study examined the isokinetic hamstrings-to-quadriceps (H:Q) ratio and bilateral leg strength balance in 40 male college (age: 23.4 ± 2.5 yrs) team sport players (field sport = 23, soccer players; court sport = 17, volleyball and basketball players). Five repetitions of maximal knee concentric flexion and concentric extension were performed on an isokinetic dynamometer at two speeds (slow: 60°·s(-1) and fast: 300°·s(-1)) with 3 minutes rest between tests. Both legs were measured in counterbalanced order with the dominant leg being determined as the leg used to kick a ball. The highest concentric peak torque values (Nm) of the hamstrings and quadriceps of each leg were analyzed after body mass normalization (Nm·kg(-1)). Court sport players showed significantly weaker dominant leg hamstrings muscles at both contraction speeds (P < 0.05). The H:Q ratio was significantly larger in field players in their dominant leg at 60°·s(-1) (P < 0.001), and their non-dominant leg at 300°·s(-1) (P < 0.001) respectively. Sport-specific leg muscle strength was evident in college players from field and court sports. These results suggest the need for different muscle strength training and rehabilitation protocols for college players according to the musculature requirements in their respective sports.

Veto player theory and reform making in Western Europe.

PubMed

Angelova, Mariyana; Bäck, Hanna; Müller, Wolfgang C; Strobl, Daniel

2018-05-01

Veto player theory generates predictions about governments' capacity for policy change. Due to the difficulty of identifying significant laws needed to change the policy status quo, evidence about governments' ability to change policy has been mostly provided for a limited number of reforms and single-country studies. To evaluate the predictive power of veto player theory for policy making across time, policy areas and countries, a dataset was gathered that incorporates about 5,600 important government reform measures in the areas of social, labour, economic and taxation policy undertaken in 13 Western European countries from the mid-1980s until the mid-2000s. Veto player theory is applied in a combined model with other central theoretical expectations on policy change derived from political economy (crisis-driven policy change) and partisan theory (ideology-driven policy change). Robust support is found that governments introduce more reform measures when economic conditions are poor and when the government is positioned further away from the policy status quo. No empirical support is found for predictions of veto player theory in its pure form, where no differentiation between government types is made. However, the findings provide support for the veto player theory in the special case of minimal winning cabinets, where the support of all government parties is sufficient (in contrast to minority cabinets) and necessary (in contrast to oversized cabinets) for policy change. In particular, it is found that in minimal winning cabinets the ideological distance between the extreme government parties significantly decreases the government's ability to introduce reforms. These findings improve our understanding of reform making in parliamentary democracies and highlight important issues and open questions for future applications and tests of the veto player theory.

Veto player theory and reform making in Western Europe

PubMed Central

ANGELOVA, MARIYANA; BÄCK, HANNA; MÜLLER, WOLFGANG C.

2017-01-01

Abstract Veto player theory generates predictions about governments’ capacity for policy change. Due to the difficulty of identifying significant laws needed to change the policy status quo, evidence about governments’ ability to change policy has been mostly provided for a limited number of reforms and single‐country studies. To evaluate the predictive power of veto player theory for policy making across time, policy areas and countries, a dataset was gathered that incorporates about 5,600 important government reform measures in the areas of social, labour, economic and taxation policy undertaken in 13 Western European countries from the mid‐1980s until the mid‐2000s. Veto player theory is applied in a combined model with other central theoretical expectations on policy change derived from political economy (crisis‐driven policy change) and partisan theory (ideology‐driven policy change). Robust support is found that governments introduce more reform measures when economic conditions are poor and when the government is positioned further away from the policy status quo. No empirical support is found for predictions of veto player theory in its pure form, where no differentiation between government types is made. However, the findings provide support for the veto player theory in the special case of minimal winning cabinets, where the support of all government parties is sufficient (in contrast to minority cabinets) and necessary (in contrast to oversized cabinets) for policy change. In particular, it is found that in minimal winning cabinets the ideological distance between the extreme government parties significantly decreases the government's ability to introduce reforms. These findings improve our understanding of reform making in parliamentary democracies and highlight important issues and open questions for future applications and tests of the veto player theory. PMID:29695891

Identifying Key Words in 9-1-1 Calls for Stroke: A Mixed Methods Approach.

PubMed

Richards, Christopher T; Wang, Baiyang; Markul, Eddie; Albarran, Frank; Rottman, Doreen; Aggarwal, Neelum T; Lindeman, Patricia; Stein-Spencer, Leslee; Weber, Joseph M; Pearlman, Kenneth S; Tataris, Katie L; Holl, Jane L; Klabjan, Diego; Prabhakaran, Shyam

2017-01-01

Identifying stroke during a 9-1-1 call is critical to timely prehospital care. However, emergency medical dispatchers (EMDs) recognize stroke in less than half of 9-1-1 calls, potentially due to the words used by callers to communicate stroke signs and symptoms. We hypothesized that callers do not typically use words and phrases considered to be classical descriptors of stroke, such as focal neurologic deficits, but that a mixed-methods approach can identify words and phrases commonly used by 9-1-1 callers to describe acute stroke victims. We performed a mixed-method, retrospective study of 9-1-1 call audio recordings for adult patients with confirmed stroke who were transported by ambulance in a large urban city. Content analysis, a qualitative methodology, and computational linguistics, a quantitative methodology, were used to identify key words and phrases used by 9-1-1 callers to describe acute stroke victims. Because a caller's level of emotional distress contributes to the communication during a 9-1-1 call, the Emotional Content and Cooperation Score was scored by a multidisciplinary team. A total of 110 9-1-1 calls, received between June and September 2013, were analyzed. EMDs recognized stroke in 48% of calls, and the emotional state of most callers (95%) was calm. In 77% of calls in which EMDs recognized stroke, callers specifically used the word "stroke"; however, the word "stroke" was used in only 38% of calls. Vague, non-specific words and phrases were used to describe stroke victims' symptoms in 55% of calls, and 45% of callers used distractor words and phrases suggestive of non-stroke emergencies. Focal neurologic symptoms were described in 39% of calls. Computational linguistics identified 9 key words that were more commonly used in calls where the EMD identified stroke. These words were concordant with terms identified through qualitative content analysis. Most 9-1-1 callers used vague, non-specific, or distractor words and phrases and infrequently

Examining key design decisions involved in developing a serious game for child sexual abuse prevention.

PubMed

Stieler-Hunt, Colleen; Jones, Christian M; Rolfe, Ben; Pozzebon, Kay

2014-01-01

This paper presents a case study of the key decisions made in the design of Orbit, a child sexual abuse prevention computer game targeted at school students between 8 and 10 years of age. Key decisions include providing supported delivery for the target age group, featuring adults in the program, not over-sanitizing game content, having a focus on building healthy self-concept of players, making the game engaging and relatable for all players and evaluating the program. This case study has implications for the design of Serious Games more generally, including that research should underpin game design decisions, game designers should consider ways of bridging the game to real life, the learning that arises from the game should go beyond rote-learning, designers should consider how the player can make the game-world their own and comprehensive evaluations of Serious Games should be undertaken.

Examining key design decisions involved in developing a serious game for child sexual abuse prevention

PubMed Central

Stieler-Hunt, Colleen; Jones, Christian M.; Rolfe, Ben; Pozzebon, Kay

2014-01-01

This paper presents a case study of the key decisions made in the design of Orbit, a child sexual abuse prevention computer game targeted at school students between 8 and 10 years of age. Key decisions include providing supported delivery for the target age group, featuring adults in the program, not over-sanitizing game content, having a focus on building healthy self-concept of players, making the game engaging and relatable for all players and evaluating the program. This case study has implications for the design of Serious Games more generally, including that research should underpin game design decisions, game designers should consider ways of bridging the game to real life, the learning that arises from the game should go beyond rote-learning, designers should consider how the player can make the game-world their own and comprehensive evaluations of Serious Games should be undertaken. PMID:24550880

Identifying key genes associated with acute myocardial infarction

PubMed Central

Cheng, Ming; An, Shoukuan; Li, Junquan

2017-01-01

Abstract Background: This study aimed to identify key genes associated with acute myocardial infarction (AMI) by reanalyzing microarray data. Methods: Three gene expression profile datasets GSE66360, GSE34198, and GSE48060 were downloaded from GEO database. After data preprocessing, genes without heterogeneity across different platforms were subjected to differential expression analysis between the AMI group and the control group using metaDE package. P < .05 was used as the cutoff for a differentially expressed gene (DEG). The expression data matrices of DEGs were imported in ReactomeFIViz to construct a gene functional interaction (FI) network. Then, DEGs in each module were subjected to pathway enrichment analysis using DAVID. MiRNAs and transcription factors predicted to regulate target DEGs were identified. Quantitative real-time polymerase chain reaction (RT-PCR) was applied to verify the expression of genes. Result: A total of 913 upregulated genes and 1060 downregulated genes were identified in the AMI group. A FI network consists of 21 modules and DEGs in 12 modules were significantly enriched in pathways. The transcription factor-miRNA-gene network contains 2 transcription factors FOXO3 and MYBL2, and 2 miRNAs hsa-miR-21-5p and hsa-miR-30c-5p. RT-PCR validations showed that expression levels of FOXO3 and MYBL2 were significantly increased in AMI, and expression levels of hsa-miR-21–5p and hsa-miR-30c-5p were obviously decreased in AMI. Conclusion: A total of 41 DEGs, such as SOCS3, VAPA, and COL5A2, are speculated to have roles in the pathogenesis of AMI; 2 transcription factors FOXO3 and MYBL2, and 2 miRNAs hsa-miR-21-5p and hsa-miR-30c-5p may be involved in the regulation of the expression of these DEGs. PMID:29049183

Offensive tactical thinking level of wheelchair basketball players in Arab countries.

PubMed

Hindawi, Omar S; Orabi, Samira; Al Arjan, Jafar; Judge, Lawrence W; Cottingham, Michael; Bellar, David Michael

2013-01-01

The purpose of this study was to assess the appropriateness of offensive tactical decision-making of Arab basketball players, and to determine if there are differences in the appropriateness of offensive tactical decision-making within the various disability classifications of Arab basketball players. A twenty-question survey was formulated to assess decision-making in offensive tactical situations in wheelchair basketball players. Participants in the present study were 108 athletes from 10 Arab national teams participating in wheelchair basketball. The mean offensive tactical thinking level of wheelchair basketball players in the 20 different situations in the Arab countries ranged between 1.38-2.84, and the standard deviations for these 20 means ranged from 0.41 to 0.90. The total mean of all tactical situations was 2.33, which is moderate thinking level. The influence of the disability classification on the offensive tactical thinking of wheelchair basketball players was addressed by examining the data via a one-way ANOVA. The ANOVA revealed no significant differences among disability classifications/categories in tactical thinking (F(3, 104)=1.12, p=0.34). This study represents the first attempt to identify why Arab nations have not consistently qualified for the Paralympics or World Championships. These findings indicate that the moderate offensive tactical thinking level of wheelchair basketball players on Arab national teams may be part of the reason that performances of these teams have not been as strong as they would like.

[Dietary behaviours of volleyball and basketball players].

PubMed

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

Chess players' fame versus their merit.

PubMed

Simkin, M V; Roychowdhury, V P

2015-12-12

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 the 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.

Stochastic stability in three-player games.

PubMed

Kamiński, Dominik; Miekisz, Jacek; Zaborowski, Marcin

2005-11-01

Animal behavior and evolution can often be described by game-theoretic models. Although in many situations the number of players is very large, their strategic interactions are usually decomposed into a sum of two-player games. Only recently were evolutionarily stable strategies defined for multi-player games and their properties analyzed [Broom, M., Cannings, C., Vickers, G.T., 1997. Multi-player matrix games. Bull. Math. Biol. 59, 931-952]. Here we study the long-run behavior of stochastic dynamics of populations of randomly matched individuals playing symmetric three-player games. We analyze the stochastic stability of equilibria in games with multiple evolutionarily stable strategies. We also show that, in some games, a population may not evolve in the long run to an evolutionarily stable equilibrium.

Key clinical features to identify girls with CDKL5 mutations.

PubMed

Bahi-Buisson, Nadia; Nectoux, Juliette; Rosas-Vargas, Haydeé; Milh, Mathieu; Boddaert, Nathalie; Girard, Benoit; Cances, Claude; Ville, Dorothée; Afenjar, Alexandra; Rio, Marlène; Héron, Delphine; N'guyen Morel, Marie Ange; Arzimanoglou, Alexis; Philippe, Christophe; Jonveaux, Philippe; Chelly, Jamel; Bienvenu, Thierry

2008-10-01

Mutations in the human X-linked cyclin-dependent kinase-like 5 (CDKL5) gene have been shown to cause infantile spasms as well as Rett syndrome (RTT)-like phenotype. To date, less than 25 different mutations have been reported. So far, there are still little data on the key clinical diagnosis criteria and on the natural history of CDKL5-associated encephalopathy. We screened the entire coding region of CDKL5 for mutations in 183 females with encephalopathy with early seizures by denaturing high liquid performance chromatography and direct sequencing, and we identified in 20 unrelated girls, 18 different mutations including 7 novel mutations. These mutations were identified in eight patients with encephalopathy with RTT-like features, five with infantile spasms and seven with encephalopathy with refractory epilepsy. Early epilepsy with normal interictal EEG and severe hypotonia are the key clinical features in identifying patients likely to have CDKL5 mutations. Our study also indicates that these patients clearly exhibit some RTT features such as deceleration of head growth, stereotypies and hand apraxia and that these RTT features become more evident in older and ambulatory patients. However, some RTT signs are clearly absent such as the so called RTT disease profile (period of nearly normal development followed by regression with loss of acquired fine finger skill in early childhood and characteristic intensive eye communication) and the characteristic evolution of the RTT electroencephalogram. Interestingly, in addition to the overall stereotypical symptomatology (age of onset and evolution of the disease) resulting from CDKL5 mutations, atypical forms of CDKL5-related conditions have also been observed. Our data suggest that phenotypic heterogeneity does not correlate with the nature or the position of the mutations or with the pattern of X-chromosome inactivation, but most probably with the functional transcriptional and/or translational consequences of CDKL5

Comprehensive Investigation of White Matter Tracts in Professional Chess Players and Relation to Expertise: Region of Interest and DMRI Connectometry.

PubMed

Mayeli, Mahsa; Rahmani, Farzaneh; Aarabi, Mohammad Hadi

2018-01-01

Purpose: Expertise is the product of training. Few studies have used functional connectivity or conventional diffusometric methods to identify neural underpinnings of chess expertise. Diffusometric variables of white matter might reflect these adaptive changes, along with changes in structural connectivity, which is a sensitive measure of microstructural changes. Method: Diffusometric variables of 29 professional chess players and 29 age-sex matched controls were extracted for white matter regions based on John Hopkin's Mori white matter atlas and partially correlated against professional training time and level of chess proficiency. Diffusion MRI connectometry was implemented to identify changes in structural connectivity in professional players compared to novices. Result: Compared to novices, higher planar anisotropy (CP) was observed in inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus (SLF) and cingulate gyrus, in professional chess players, which correlated with higher RPM score in this group. Higher fractional anisotropy (FA) was observed in ILF, uncinate fasciculus (UF) and hippocampus and correlated with better scores in Raven's progressive matrices (RPM) score and longer duration of chess training in professional players. Consistently, radial diffusivity in bilateral IFOF, bilateral ILF and bilateral SLF was inversely correlated with level of training in professional players. DMRI connectometry analysis identified increased connectivity in bilateral UF, bilateral IFOF, bilateral cingulum, and corpus callosum in chess player's compared to controls. Conclusion: Structural connectivity of major associational subcortical white matter fibers are increased in professional chess players. FA and CP of ILF, SLF and UF directly correlates with duration of professional training and RPM score, in professional chess players.

Comprehensive Investigation of White Matter Tracts in Professional Chess Players and Relation to Expertise: Region of Interest and DMRI Connectometry

PubMed Central

Mayeli, Mahsa; Rahmani, Farzaneh; Aarabi, Mohammad Hadi

2018-01-01

Purpose: Expertise is the product of training. Few studies have used functional connectivity or conventional diffusometric methods to identify neural underpinnings of chess expertise. Diffusometric variables of white matter might reflect these adaptive changes, along with changes in structural connectivity, which is a sensitive measure of microstructural changes. Method: Diffusometric variables of 29 professional chess players and 29 age-sex matched controls were extracted for white matter regions based on John Hopkin's Mori white matter atlas and partially correlated against professional training time and level of chess proficiency. Diffusion MRI connectometry was implemented to identify changes in structural connectivity in professional players compared to novices. Result: Compared to novices, higher planar anisotropy (CP) was observed in inferior longitudinal fasciculus (ILF), superior longitudinal fasciculus (SLF) and cingulate gyrus, in professional chess players, which correlated with higher RPM score in this group. Higher fractional anisotropy (FA) was observed in ILF, uncinate fasciculus (UF) and hippocampus and correlated with better scores in Raven's progressive matrices (RPM) score and longer duration of chess training in professional players. Consistently, radial diffusivity in bilateral IFOF, bilateral ILF and bilateral SLF was inversely correlated with level of training in professional players. DMRI connectometry analysis identified increased connectivity in bilateral UF, bilateral IFOF, bilateral cingulum, and corpus callosum in chess player's compared to controls. Conclusion: Structural connectivity of major associational subcortical white matter fibers are increased in professional chess players. FA and CP of ILF, SLF and UF directly correlates with duration of professional training and RPM score, in professional chess players. PMID:29773973

Identifying MMORPG Bots: A Traffic Analysis Approach

NASA Astrophysics Data System (ADS)

Chen, Kuan-Ta; Jiang, Jhih-Wei; Huang, Polly; Chu, Hao-Hua; Lei, Chin-Laung; Chen, Wen-Chin

2008-12-01

Massively multiplayer online role playing games (MMORPGs) have become extremely popular among network gamers. Despite their success, one of MMORPG's greatest challenges is the increasing use of game bots, that is, autoplaying game clients. The use of game bots is considered unsportsmanlike and is therefore forbidden. To keep games in order, game police, played by actual human players, often patrol game zones and question suspicious players. This practice, however, is labor-intensive and ineffective. To address this problem, we analyze the traffic generated by human players versus game bots and propose general solutions to identify game bots. Taking Ragnarok Online as our subject, we study the traffic generated by human players and game bots. We find that their traffic is distinguishable by 1) the regularity in the release time of client commands, 2) the trend and magnitude of traffic burstiness in multiple time scales, and 3) the sensitivity to different network conditions. Based on these findings, we propose four strategies and two ensemble schemes to identify bots. Finally, we discuss the robustness of the proposed methods against countermeasures of bot developers, and consider a number of possible ways to manage the increasingly serious bot problem.

La mala educación of tumor-associated macrophages: Diverse pathways and new players.

PubMed

Mantovani, Alberto

2010-02-17

Inflammation is a key component of the tumor microenvironment. Two reports published in this issue of Cancer Cell, Andreu et al. and Erez et al., shed new light on pathways and players involved in the orchestration of cancer-related inflammation. 2010 Elsevier Inc. All rights reserved.

Y-balance normative data for female collegiate volleyball players.

PubMed

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.

The hydration status of young female elite soccer players during an official tournament.

PubMed

Chapelle, Laurent; Tassignon, Bruno; Aerenhouts, Dirk; Mullie, Patrick; Clarys, Peter

2017-09-01

The hydration status of elite female soccer players is a concern, especially during high-volume training periods or tournaments. Furthermore, scientific literature on this topic is scarce to non-existent. Therefore, the primary aim of this study was to evaluate the hydration status in elite youth female soccer players during an official tournament. The secondary aim was to identify a possible relationship between pre-training hydration status and fluid intake. Eighteen players were followed during eight consecutive days. Urine specific gravity was used to assess hydration status. Body weight was monitored before and after every training and match, whilst individual fluid intake was only registered during training. The players were informed about their hydration status on day 5. On days 1 to 4, the percentage of players who were at least minimally hypohydrated ranged between 44% and 78%. On day 5 (rest day), all the players were at least minimally hypohydrated. After the information session on day 5, the relative number of euhydrated players increased to 89% on both day 6 (training day) and day 7 (match day). On the final day (rest day), all players were either minimally hypohydrated or hypohydrated. Furthermore, a moderate and significant negative correlation (r=-0.44; N.=54; P=0.01) was found between fluid intake during and USG value before the training sessions. The data illustrates that the hydration status of this population of elite youth female soccer players may be suboptimal and is of substantial concern on rest days during this tournament under temperate conditions. Receiving personal advice about rehydration seems to have a positive effect.

Prediction of Tennis Performance in Junior Elite Tennis Players

PubMed Central

Kramer, Tamara; Huijgen, Barbara C.H.; Elferink-Gemser, Marije T.; Visscher, Chris

2017-01-01

. Future research should focus on other aspects in order to predict tennis performance better. Key points In boys, tennis performance can be partly explained by upper body power at U13, it is not a predictor for performance at U16. In girls, APHV is of influence for tennis performance at U13 and U16. At younger age earlier-matured girls were ranked higher, however at U16 later-matured girls were ranked higher. Overall, physical fitness in junior tennis is important for monitoring physical fitness development however this should not solely be used for selection criteria in a homogenous group of junior elite players. PMID:28344446

Iterative key-residues interrogation of a phytase with thermostability increasing substitutions identified in directed evolution.

PubMed

Shivange, Amol V; Roccatano, Danilo; Schwaneberg, Ulrich

2016-01-01

Bacterial phytases have attracted industrial interest as animal feed supplement due to their high activity and sufficient thermostability (required for feed pelleting). We devised an approach named KeySIDE,  an iterative Key-residues interrogation of the wild type with Substitutions Identified in Directed Evolution for improving Yersinia mollaretii phytase (Ymphytase) thermostability by combining key beneficial substitutions and elucidating their individual roles. Directed evolution yielded in a discovery of nine positions in Ymphytase and combined iteratively to identify key positions. The "best" combination (M6: T77K, Q154H, G187S, and K289Q) resulted in significantly improved thermal resistance; the residual activity improved from 35 % (wild type) to 89 % (M6) at 58 °C and 20-min incubation. Melting temperature increased by 3 °C in M6 without a loss of specific activity. Molecular dynamics simulation studies revealed reduced flexibility in the loops located next to helices (B, F, and K) which possess substitutions (Helix-B: T77K, Helix-F: G187S, and Helix-K: K289E/Q). Reduced flexibility in the loops might be caused by strengthened hydrogen bonding network (e.g., G187S and K289E/K289Q) and a salt bridge (T77K). Our results demonstrate a promising approach to design phytases in food research, and we hope that the KeySIDE might become an attractive approach for understanding of structure-function relationships of enzymes.

Number of Players and Relative Pitch Area per Player: Comparing Their Influence on Heart Rate and Physical Demands in Under-12 and Under-13 Football Players.

PubMed

Castellano, Julen; Puente, Asier; Echeazarra, Ibon; Usabiaga, Oidui; Casamichana, David

2016-01-01

The aim of the present study is to analyse the influence of different large-sided games (LSGs) on the physical and physiological variables in under-12s (U12) and -13s (U13) soccer players. The effects of the combination of different number of players per team, 7, 9, and 11 (P7, P9, and P11, respectively) with three relative pitch areas, 100, 200, and 300 m(2) (A100, A200, and A300, respectively), were analysed in this study. The variables analysed were: 1) global indicator such as total distance (TD); work:rest ratio (W:R); player-load (PL) and maximal speed (Vmax); 2) heart rate (HR) mean and time spent in different intensity zones of HR (<75%, 75-84%, 84-90% and >90%), and; 3) five absolute (<8, 8-13, 13-16 and >16 Km h(-1)) and three relative speed categories (<40%, 40-60% and >60% Vmax). The results support the theory that a change in format (player number and pitch dimensions) affects no similarly in the two players categories. Although it can seem that U13 players are more demanded in this kind of LSG, when the work load is assessed from a relative point of view, great pitch dimensions and/or high number of player per team are involved in the training task to the U12 players. The results of this study could alert to the coaches to avoid some types of LSGs for the U12 players such as: P11 played in A100, A200 or A300, P9 played in A200 or A300 and P7 played in A300 due to that U13>U12 in several physical and physiological variables (W:R, time spent in 84-90%HRmax, distance in 8-13 and 13-16 Km h(-1) and time spent in 40-60%Vmax). These results may help youth soccer coaches to plan the progressive introduction of LSGs so that task demands are adapted to the physiological and physical development of participants.

Pectoralis major ruptures in professional American football players.

PubMed

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.

Randomness in nonlocal games between mistrustful players.

PubMed

Miller, Carl A; Shi, Yaoyun

2017-06-01

If two quantum players at a nonlocal game G achieve a superclassical score, then their measurement outcomes must be at least partially random from the perspective of any third player. This is the basis for device-independent quantum cryptography. In this paper we address a related question: does a superclassical score at G guarantee that one player has created randomness from the perspective of the other player? We show that for complete-support games, the answer is yes: even if the second player is given the first player's input at the conclusion of the game, he cannot perfectly recover her output. Thus some amount of local randomness (i.e., randomness possessed by only one player) is always obtained when randomness is certified from nonlocal games with quantum strategies. This is in contrast to non-signaling game strategies, which may produce global randomness without any local randomness. We discuss potential implications for cryptographic protocols between mistrustful parties.

Morphological and motor characteristics of Croatian first league female football players.

PubMed

Jelaska, Petra Mandić; Katić, Ratko; Jelaska, Igor

2013-05-01

describe morphological and motor status of first league female football players. Furthermore, the linear regression results in latent space showed that the identified factors are very good predictors of female football players quality (delta = 0.959). In doing so, both specific motor abilities factors and the first factor of basic motor abilities as a factor of general motor efficiency have the greatest impact on player quality, and these factors have been identified as most important predictors of player quality in Croatian women's first league and elite female football players in general. Obtained results provide deep insight into the structure of relations between the morphological, motor and specific motor variables and also indicate the importance of such definition of specific motor abilities. Consequently, results explicitly indicate the necessity of early, continuous, and systematic development of football-specific motor abilities in female football players of high competitive level but also, adjusted, to the younger age categories.

Anterior Cruciate Ligament Injuries in Baseball Players.

PubMed

Dugas, Jeffrey R; Bedford, Benjamin B; Andrachuk, John S; Scillia, Anthony J; Aune, Kyle T; Cain, E Lyle; Andrews, James R; Fleisig, Glenn S

2016-11-01

To determine common mechanisms of anterior cruciate ligament (ACL) injury in baseball players and to quantify the rate of return to play after primary surgical reconstruction and review intermediate clinical outcomes. Surgical injuries involving the ACL in youth, high school, collegiate, and professional baseball players were queried for an 11-year period (2001 to 2011). Over the study period, 42 baseball players were identified who had undergone arthroscopically assisted primary ACL reconstruction by 1 of 3 attending surgeons. Retrospective chart review was performed for all 42 patients to evaluate variables of age, level of competition, position, mechanism of injury, graft choice, and associated meniscal injuries. Twenty-six patients were reached for telephone survey and International Knee Documentation Committee questionnaire and they answered questions about their original injury and playing history. The most common mechanism of injury was fielding, followed by base running. Infielders and outfielders (32% each) were the most commonly injured position, followed by pitchers (29%). Among the 32 players for whom it could be determined, 30 (94%) were able to return to playing baseball at a mean follow-up of 4.2 years (range 1.0 to 9.9 years). The mean International Knee Documentation Committee score was 84.0 (range 63 to 91). Among the 26 patients contacted for telephone interview, no one required revision ACL surgery, but 3 required a subsequent procedure for meniscal tear. Twenty-five patients (96%) denied any episodes of instability in the knee after reconstruction. The overwhelming majority of baseball players that sustain ACL injuries do so while fielding or base running. Outfielders are significantly more likely than infielders to suffer ACL injuries while fielding versus base running. The results with respect to return to play are promising, as nearly all patients were able to return to baseball and none required a revision ACL surgery at a mean follow

Attributes of top elite team-handball players.

PubMed

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 < 0.05) contributed to predict the probability of an athlete to be a top elite team-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

The consultation of rugby players in co-developing a player health study: feasibility and consequences of sports participants as research partners.

PubMed

Davies, Madeleine A M; Balai, Edward; Adams, Jo; Carter, John-Henry; Judge, Andrew; Newton, Julia L; Arden, Nigel K

2017-01-01

Many funding bodies within the United Kingdom and globally have encouraged public involvement in research. The Department of Health has also called public involvement a sign of good research. Despite the wide acceptance of public involvement improving many aspects of research, from its design to its communication, involvement has varied levels of implementation across different fields of research. Sports people have rarely been involved in research, partly as this research tends not to be funded by mainstream funding bodies. This may lead to a lower research quality, not founded in player ('service user') experiences. When creating a study of former rugby player health, we were very keen to involve rugby players, understand their thoughts on player health, and their playing experiences. This article explains how rugby players were involved in several ways, but mainly in group discussions during the design stage. These groups helped to inform our study's aims and questionnaire, ensure the questionnaire would capture player experiences and answer questions relevant to players, that they would like to understand after their participation in rugby. We found that these groups were easy to arrange, and that in only one session with each group, we were given many ideas of how to improve the questionnaire and study. We believe that other studies in sports should involve sports people, and that this is a useful activity that will change data collection forms and processes, improving the research, helping researchers, and making studies more suitable for players who take part in them. Background Patient and public involvement ('involvement') in the UK has increased in accordance with funding requirements, patient-centered health policy initiatives and reporting of the positive impact of involvement for those involved, research and researchers. However, involvement has not been implemented equally across all disease areas and populations. The aim of this process was to

Identifying Regional Key Eco-Space to Maintain Ecological Security Using GIS

PubMed Central

Xie, Hualin; Yao, Guanrong; Wang, Peng

2014-01-01

Ecological security and environmental sustainability are the foundations of sustainable development. With the acceleration of urbanization, increasing human activities have promoted greater impacts on the eco-spaces that maintain ecological security. Regional key eco-space has become the primary need to maintain environmental sustainability and can offer society with continued ecosystem services. In this paper, considering the security of water resources, biodiversity conservation, disaster avoidance and protection and natural recreation, an integrated index of eco-space importance was established and a method for identifying key eco-space was created using GIS, with Lanzhou City, China as a case study. The results show that the area of core eco-space in the Lanzhou City is approximately 50,908.7 hm2, accounting for 40% of the region’s total area. These areas mainly consist of geological hazard protection zones and the core zones of regional river systems, wetlands, nature reserves, forest parks and scenic spots. The results of this study provide some guidance for the management of ecological security, ecological restoration and environmental sustainability. PMID:24590051

Physiological profiles and sport specific fitness of Asian elite squash players.

PubMed Central

Chin, M K; Steininger, K; So, R C; Clark, C R; Wong, A S

1995-01-01

There is a scarcity of descriptive data on the physiological characteristics of elite Asian squash players. The purpose of this study was to evaluate the physiological profile and sports specific fitness of Hong Kong elite squash players. It was conducted before the selection of the Hong Kong national squash team for the 1992 Asian Squash Championship. Ten elite squash players were selected as subjects for the study. Maximum oxygen uptake was measured using a continuous treadmill running test. A sports specific field test was performed in a squash court. The following means (s.d.) were observed: height 172.6(4.3) cm; weight 67.7(6.9) kg; body fat 7.4(3.4)%; forced vital capacity (FVC) 5.13(0.26) litres; maximum oxygen uptake (VO2max) 61.7(3.4) ml.kg-1.min-1; anaerobic threshold (AT) 80.2(3.3)% of VO2max; alactic power index 15.5(1.8) W.kg-1; lactic work index 323.5(29.4) J.kg-1, peak isokinetic dominant knee extensor and flexor strengths 3.11(0.29) Nm.kg-1 and 1.87(0.18) Nm.kg-1. The results show that the Hong Kong squash players have relatively high cardiorespiratory sports specific fitness and muscle strength which may be one of the key factors that contributed to the success of the Hong Kong team in the Asian Championship. PMID:8800847

Finding solid ground: law enforcement, key populations and their health and rights in South Africa

PubMed Central

Scheibe, Andrew; Howell, Simon; Müller, Alexandra; Katumba, Munyaradzi; Langen, Bram; Artz, Lillian; Marks, Monique

2016-01-01

Introduction Sex workers, people who use drugs, men who have sex with men, women who have sex with women and transgender people in South Africa frequently experience high levels of stigma, abuse and discrimination. Evidence suggests that such abuse is sometimes committed by police officers, meaning that those charged with protection are perpetrators. This reinforces cycles of violence, increases the risk of HIV infection, undermines HIV prevention and treatment interventions and violates the constitutional prescriptions that the police are mandated to protect. This paper explores how relationship building can create positive outcomes while taking into account the challenges associated with reforming police strategies in relation to key populations, and vice versa. Discussion We argue that relationships between law enforcement agencies and key populations need to be re-examined and reconstituted to enable appropriate responses and services. The antagonistic positioning, “othering” and blame assignment frequently seen in interactions between law enforcement officials and key populations can negatively influence both, albeit for different reasons. In addressing these concerns, we argue that mediation based on consensual dialogue is required, and can be harnessed through a process that highlights points of familiarity that are often shared, but not understood, by both parties. Rather than laying blame, we argue that substantive changes need to be owned and executed by all role-players, informed by a common language that is cognisant of differing perspectives. Conclusions Relational approaches can be used to identify programmes that align goals that are part of law enforcement, human rights and public health despite not always being seen as such. Law enforcement champions and representatives of key populations need to be identified and supported to promote interventions that are mutually reinforcing, and address perceived differences by highlighting commonality

Finding solid ground: law enforcement, key populations and their health and rights in South Africa.

PubMed

Scheibe, Andrew; Howell, Simon; Müller, Alexandra; Katumba, Munyaradzi; Langen, Bram; Artz, Lillian; Marks, Monique

2016-01-01

Sex workers, people who use drugs, men who have sex with men, women who have sex with women and transgender people in South Africa frequently experience high levels of stigma, abuse and discrimination. Evidence suggests that such abuse is sometimes committed by police officers, meaning that those charged with protection are perpetrators. This reinforces cycles of violence, increases the risk of HIV infection, undermines HIV prevention and treatment interventions and violates the constitutional prescriptions that the police are mandated to protect. This paper explores how relationship building can create positive outcomes while taking into account the challenges associated with reforming police strategies in relation to key populations, and vice versa. We argue that relationships between law enforcement agencies and key populations need to be re-examined and reconstituted to enable appropriate responses and services. The antagonistic positioning, "othering" and blame assignment frequently seen in interactions between law enforcement officials and key populations can negatively influence both, albeit for different reasons. In addressing these concerns, we argue that mediation based on consensual dialogue is required, and can be harnessed through a process that highlights points of familiarity that are often shared, but not understood, by both parties. Rather than laying blame, we argue that substantive changes need to be owned and executed by all role-players, informed by a common language that is cognisant of differing perspectives. Relational approaches can be used to identify programmes that align goals that are part of law enforcement, human rights and public health despite not always being seen as such. Law enforcement champions and representatives of key populations need to be identified and supported to promote interventions that are mutually reinforcing, and address perceived differences by highlighting commonality. Creating opportunities to share experiences

Identification of key micro-organisms involved in Douchi fermentation by statistical analysis and their use in an experimental fermentation.

PubMed

Chen, C; Xiang, J Y; Hu, W; Xie, Y B; Wang, T J; Cui, J W; Xu, Y; Liu, Z; Xiang, H; Xie, Q

2015-11-01

To screen and identify safe micro-organisms used during Douchi fermentation, and verify the feasibility of producing high-quality Douchi using these identified micro-organisms. PCR-denaturing gradient gel electrophoresis (DGGE) and automatic amino-acid analyser were used to investigate the microbial diversity and free amino acids (FAAs) content of 10 commercial Douchi samples. The correlations between microbial communities and FAAs were analysed by statistical analysis. Ten strains with significant positive correlation were identified. Then an experiment on Douchi fermentation by identified strains was carried out, and the nutritional composition in Douchi was analysed. Results showed that FAAs and relative content of isoflavone aglycones in verification Douchi samples were generally higher than those in commercial Douchi samples. Our study indicated that fungi, yeasts, Bacillus and lactic acid bacteria were the key players in Douchi fermentation, and with identified probiotic micro-organisms participating in fermentation, a higher quality Douchi product was produced. This is the first report to analyse and confirm the key micro-organisms during Douchi fermentation by statistical analysis. This work proves fermentation micro-organisms to be the key influencing factor of Douchi quality, and demonstrates the feasibility of fermenting Douchi using identified starter micro-organisms. © 2015 The Society for Applied Microbiology.

Concussion guideline implementation perceptions and experiences among parents of community-level Australian Football junior players

PubMed Central

White, Peta E; Register-Mihalik, Johna; Donaldson, Alex; Sullivan, S John

2017-01-01

Background/aim Concussion guidelines exist for multiple community sports. Parents are key stakeholders in guideline implementation and in appropriate responses following concussive injury. The purpose of this qualitative investigation was to understand how parents of community-level Australian Football (AF) players experience and perceive concussion guidelines in order to inform the design and implementation of concussion guidelines in community sport. Methods A cross-sectional qualitative approach was adopted to allow for an open and detailed exploration of the views of parents of junior community AF players (ie, those aged <16 years) regarding concussion guidelines of the AF League (AFL)—the national governing body for AF. Participants were 15 parents of junior community AF players from two clubs affiliated with a large regional community AF League. Results The key experiences and perceptions of the parents included appreciation that the guidelines outlined the postconcussion process that should be followed, desires for better understanding of the guidelines by general practitioners (ie, medical doctors) who care for children with concussion, having more readily available information for parents and receiving more formal policy guiding timing of return-to-participation following concussion. Difficulties with the guidelines not addressing delayed presentations of concussion were also frequently mentioned. Conclusions Parents are key stakeholders in concussion prevention and care in community sport. As such, their input should be considered when developing guidelines and resources for community sport. Furthermore, concussion information should be made available to parents in an easily accessible and community-friendly form. PMID:28761707

Historical Patterns and Variation in Treatment of Injuries in NFL (National Football League) Players and NCAA (National Collegiate Athletic Association) Division I Football Players.

PubMed

McCarty, Eric C; Kraeutler, Matthew J; Langner, Paula; Cook, Shane; Ellis, Byron; Godfrey, Jenna M

We conducted a study to identify and contrast patterns in the treatment of common injuries that occur in National Football League (NFL) players and National Collegiate Athletic Association (NCAA) Division I football players. Orthopedic team physicians for all 32 NFL and 119 NCAA Division I football teams were asked to complete a survey regarding demographics and preferred treatment of a variety of injuries encountered in football players. Responses were received from 31 (97%) of the 32 NFL and 111 (93%) of the 119 NCAA team physicians. Although patellar tendon autograft was the preferred graft choice for both groups of team physicians, the percentage of NCAA physicians who allowed return to football 6 months or less after anterior cruciate ligament reconstruction was significantly (P = .03) higher than that of NFL physicians. Prophylactic knee bracing, which may prevent medial collateral ligament injuries, was used at a significantly (P < .0001) higher rate by NCAA teams (89%) than by NFL teams (28%). Ketorolac injections were given by a significantly (P < .01) higher percentage of NFL teams (93%) than of NCAA teams (62%). Understanding the current trends in the management of these injuries is beneficial in designing studies that may help improve the treatment and prevention of injuries in football players.

The Brassinosteroid Signaling Pathway—New Key Players and Interconnections with Other Signaling Networks Crucial for Plant Development and Stress Tolerance

PubMed Central

Gruszka, Damian

2013-01-01

Brassinosteroids (BRs) are a class of steroid hormones regulating a wide range of physiological processes during the plant life cycle from seed development to the modulation of flowering and senescence. The last decades, and recent years in particular, have witnessed a significant advance in the elucidation of the molecular mechanisms of BR signaling from perception by the transmembrane receptor complex to the regulation of transcription factors influencing expression of the target genes. Application of the new approaches shed light on the molecular functions of the key players regulating the BR signaling cascade and allowed identification of new factors. Recent studies clearly indicated that some of the components of BR signaling pathway act as multifunctional proteins involved in other signaling networks regulating diverse physiological processes, such as photomorphogenesis, cell death control, stomatal development, flowering, plant immunity to pathogens and metabolic responses to stress conditions, including salinity. Regulation of some of these processes is mediated through a crosstalk between BR signalosome and the signaling cascades of other hormones, including auxin, abscisic acid, ethylene and salicylic acid. Unravelling the complicated mechanisms of BR signaling and its interconnections with other molecular networks may be of great importance for future practical applications in agriculture. PMID:23615468

Anthropometric profile and body composition of Irish adolescent rugby union players aged 16-18.

PubMed

Delahunt, Eamonn; Byrne, Risteard B; Doolin, Rachel K; McInerney, Rory G; Ruddock, Ciaran T J; Green, Brian S

2013-12-01

The literature suggests that one of the key determinants of success at rugby union international competitions is the anthropometric profile of players. The Irish Rugby Football Union (IRFU) long-term player development (LTPD) model is a framework designed to guide the development of the tactical, physical, and psychological domains of sporting participation. In Ireland, the Train-to-Train stage of the IRFU model is a critical stage, whereby the next developmental progression would include the transition of players into professional academies. To date, no previously published studies have examined the anthropometric profile of Irish Schools' rugby union players at the Train-to-Train stage of the IRFU model. The anthropometric profile of 136 male adolescent rugby union players at the Train-to-Train stage of the IRFU model was assessed using total-body dual-energy x-ray absorptiometry. Significant differences in height, body mass, body fat percentage, fat mass, lean mass, and fat-free mass were observed between players assigned to the forward and back units, and for specific position categorizations within each unit. Direct logistic regression revealed that body mass was a statistically significant (p < 0.01) predictor of unit position classification, with an odds ratio of 2.35, indicating that the players with a higher body mass were twice as likely to be classified as forwards. The results of this study indicate that at the Train-to-Train stage of the IRFU model, forward and back units have distinctly different anthropometric profiles. Furthermore, anthropometric differentiation also exists within specific position categorizations within each of these playing units. Thus, anthropometric profiling should be carried out on a systematic and periodic basis, because this will allow for the evaluation of the effectiveness of the implementation strategies of the IRFU model on a national basis.

Seasonal Mood Disturbances in Collegiate Hockey Players

PubMed Central

Rosen, Lionel W.; Shafer, Christine L.; Smokler, Carol; Carrier, David; McKeag, Douglas B.

1996-01-01

Objective: The purpose of this paper is to: 1) describe the seasonal affective disorder syndrome using a case illustration, 2) provide a simple and reliable method for identifying seasonal affective disorder, and 3) provide data as to the prevalence of the syndrome in a subset of collegiate hockey players. Design and Setting: Collegiate hockey players were selected, because their practices begin in the fall and play is completed in the spring. The teams selected for participation were from the far Northwest and the upper Midwest regions. Subjects: Sixty-eight Division I hockey players volunteered for the study. The three teams from which the subjects were chosen were located above latitude 42°/45' north. Subjects were from the northern latitudes. Measurements: The Seasonal Pattern Assessment Questionnaire was used to screen for seasonality. A sample of the athletes was also examined using the Hamilton Rating Scale for Depression together with the Diagnostic and Statistical Manual of Mental Disorders (4th ed) criteria for Seasonal Pattern Specifier. Results: Thirty-three (51%) were asymptomatic, 7 (11%) met the criteria for seasonal affective disorder, and 25 (39%) hockey players scored in the range that could classify them as candidates for subsyndromal seasonal affective disorder. Conclusions: The prevalence of seasonal affective disorder among our sample approximated the national norm for the northern latitudes. However, the prevalence of subsyndromal seasonal affective disorder in our population was 25% compared to 13% reported nationally. Light therapy has been shown to reverse the effects of the disorders; however, further research needs to be conducted to determine its acceptance and effectiveness by the athletic population. PMID:16558403

Invisible players: a family systems model.

PubMed

Hellstedt, Jon

2005-10-01

This article attempts to demonstrate that the family is a key player in the athlete's development and performance, sometimes invisible, but often all too visible. The practice of clinical sport psychology is enriched by a family-based orientation to the assessment and treatment of athletes. Creating a workable family system is a challenge for parents. They have many difficult decisions to make, and are often without support and direction in making those choices. Sport psychiatrists and psychologists can be helpful to parents as well as athletes by using family-based assessments and treatment interventions that provide education, challenge, and support as they negotiate the tasks and transitions in the family life cycle.

Auditory memory function in expert chess players

PubMed Central

Fattahi, Fariba; Geshani, Ahmad; Jafari, Zahra; Jalaie, Shohreh; Salman Mahini, Mona

2015-01-01

Background: Chess is a game that involves many aspects of high level cognition such as memory, attention, focus and problem solving. Long term practice of chess can improve cognition performances and behavioral skills. Auditory memory, as a kind of memory, can be influenced by strengthening processes following long term chess playing like other behavioral skills because of common processing pathways in the brain. The purpose of this study was to evaluate the auditory memory function of expert chess players using the Persian version of dichotic auditory-verbal memory test. Methods: The Persian version of dichotic auditory-verbal memory test was performed for 30 expert chess players aged 20-35 years and 30 non chess players who were matched by different conditions; the participants in both groups were randomly selected. The performance of the two groups was compared by independent samples t-test using SPSS version 21. Results: The mean score of dichotic auditory-verbal memory test between the two groups, expert chess players and non-chess players, revealed a significant difference (p≤ 0.001). The difference between the ears scores for expert chess players (p= 0.023) and non-chess players (p= 0.013) was significant. Gender had no effect on the test results. Conclusion: Auditory memory function in expert chess players was significantly better compared to non-chess players. It seems that increased auditory memory function is related to strengthening cognitive performances due to playing chess for a long time. PMID:26793666

Auditory memory function in expert chess players.

PubMed

Fattahi, Fariba; Geshani, Ahmad; Jafari, Zahra; Jalaie, Shohreh; Salman Mahini, Mona

2015-01-01

Chess is a game that involves many aspects of high level cognition such as memory, attention, focus and problem solving. Long term practice of chess can improve cognition performances and behavioral skills. Auditory memory, as a kind of memory, can be influenced by strengthening processes following long term chess playing like other behavioral skills because of common processing pathways in the brain. The purpose of this study was to evaluate the auditory memory function of expert chess players using the Persian version of dichotic auditory-verbal memory test. The Persian version of dichotic auditory-verbal memory test was performed for 30 expert chess players aged 20-35 years and 30 non chess players who were matched by different conditions; the participants in both groups were randomly selected. The performance of the two groups was compared by independent samples t-test using SPSS version 21. The mean score of dichotic auditory-verbal memory test between the two groups, expert chess players and non-chess players, revealed a significant difference (p≤ 0.001). The difference between the ears scores for expert chess players (p= 0.023) and non-chess players (p= 0.013) was significant. Gender had no effect on the test results. Auditory memory function in expert chess players was significantly better compared to non-chess players. It seems that increased auditory memory function is related to strengthening cognitive performances due to playing chess for a long time.

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

PubMed

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 < .001) than in players who wore a generic mouth guard. The rate of SRC was also higher (HR = 1.96 [95% CI, 1.40-2.73], P < .001) in players who had sustained an SRC within the previous 12 months (15.1% of the 259 players [95% CI, 11.0%-20.1%]) than in players without a previous SRC (8.2% of the 2028 players [95% CI, 7.1%-9.5%]). Incidence of SRC was similar regardless of the helmet brand (manufacturer) worn by high school

Athletic performance outcomes following lumbar discectomy in professional basketball players.

PubMed

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

Dynamic balance performance and noncontact lower extremity injury in college football players: an initial study.

PubMed

Butler, Robert J; Lehr, Michael E; Fink, Michael L; Kiesel, Kyle B; Plisky, Phillip J

2013-09-01

Field expedient screening tools that can identify individuals at an elevated risk for injury are needed to minimize time loss in American football players. Previous research has suggested that poor dynamic balance may be associated with an elevated risk for injury in athletes; however, this has yet to be examined in college football players. To determine if dynamic balance deficits are associated with an elevated risk of injury in collegiate football players. It was hypothesized that football players with lower performance and increased asymmetry in dynamic balance would be at an elevated risk for sustaining a noncontact lower extremity injury. Prospective cohort study. Fifty-nine collegiate American football players volunteered for this study. Demographic information, injury history, and dynamic balance testing performance were collected, and noncontact lower extremity injuries were recorded over the course of the season. Receiver operator characteristic curves were calculated based on performance on the Star Excursion Balance Test (SEBT), including composite score and asymmetry, to determine the population-specific risk cut-off point. Relative risk was then calculated based on these variables, as well as previous injury. A cut-off point of 89.6% composite score on the SEBT optimized the sensitivity (100%) and specificity (71.7%). A college football player who scored below 89.6% was 3.5 times more likely to get injured. Poor performance on the SEBT may be related to an increased risk for sustaining a noncontact lower extremity injury over the course of a competitive American football season. College football players should be screened preseason using the SEBT to identify those at an elevated risk for injury based upon dynamic balance performance to implement injury mitigation strategies to this specific subgroup of athletes.

Anthropometric, body composition and somatotype characteristics of elite female volleyball players from the highest Spanish league.

PubMed

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.

Number of Players and Relative Pitch Area per Player: Comparing Their Influence on Heart Rate and Physical Demands in Under-12 and Under-13 Football Players

PubMed Central

Castellano, Julen; Puente, Asier; Echeazarra, Ibon; Usabiaga, Oidui; Casamichana, David

2016-01-01

The aim of the present study is to analyse the influence of different large-sided games (LSGs) on the physical and physiological variables in under-12s (U12) and -13s (U13) soccer players. The effects of the combination of different number of players per team, 7, 9, and 11 (P7, P9, and P11, respectively) with three relative pitch areas, 100, 200, and 300 m2 (A100, A200, and A300, respectively), were analysed in this study. The variables analysed were: 1) global indicator such as total distance (TD); work:rest ratio (W:R); player-load (PL) and maximal speed (Vmax); 2) heart rate (HR) mean and time spent in different intensity zones of HR (<75%, 75–84%, 84–90% and >90%), and; 3) five absolute (<8, 8–13, 13–16 and >16 Km h-1) and three relative speed categories (<40%, 40–60% and >60% Vmax). The results support the theory that a change in format (player number and pitch dimensions) affects no similarly in the two players categories. Although it can seem that U13 players are more demanded in this kind of LSG, when the work load is assessed from a relative point of view, great pitch dimensions and/or high number of player per team are involved in the training task to the U12 players. The results of this study could alert to the coaches to avoid some types of LSGs for the U12 players such as: P11 played in A100, A200 or A300, P9 played in A200 or A300 and P7 played in A300 due to that U13>U12 in several physical and physiological variables (W:R, time spent in 84–90%HRmax, distance in 8–13 and 13–16 Km h-1 and time spent in 40–60%Vmax). These results may help youth soccer coaches to plan the progressive introduction of LSGs so that task demands are adapted to the physiological and physical development of participants. PMID:26752422

Leading the Game, Losing the Competition: Identifying Leaders and Followers in a Repeated Game

PubMed Central

Seip, Knut Lehre; Grøn, Øyvind

2016-01-01

We explore a new method for identifying leaders and followers, LF, in repeated games by analyzing an experimental, repeated (50 rounds) game where Row player shifts the payoff between small and large values–a type of “investor” and Column player determines who gets the payoff–a type of “manager”. We found that i) the Investor (Row) most often is a leading player and the manager (Column) a follower. The longer the Investor leads the game, the higher is both player’s payoff. Surprisingly however, it is always the Manager that achieves the largest payoff. ii) The game has an efficient cooperative strategy where the players alternate in receiving a high payoff, but the players never identify, or accept, that strategy. iii) Under the assumption that the information used by the players is closely associated with the leader- follower sequence, and that information is available before the player’s decisions are made, the players switched LF- strategy primarily as a function of information on the Investor’s investment and moves and secondly as a function of the Manager’s payoff. PMID:26968032

The incidence, prevalence, severity, mechanism and body region of injury in elite junior Australian football players: A prospective cohort study over one season.

PubMed

Lathlean, Timothy J H; Gastin, Paul B; Newstead, Stuart V; Finch, Caroline F

2018-03-14

To describe the incidence, prevalence, severity, mechanism and body region of injuries in elite junior Australian football (AF) players over one competitive season in order to help inform injury prevention interventions. Prospective cohort, data collected during the 2014 playing season. Player and staff-reported injuries sustained by 562 players from an under-18 state league were entered into an online sports injury surveillance system. An injury was recorded if it led to a missed training session or match. Injury incidence was calculated as the number of injuries per 1000h of training and competition. Injury severity was defined by the number of days players missed training or competition. Injury mechanism was identified as either contact, non-contact or overuse. There were 1192 football-related injuries sustained during the season; the majority (n=1041, 87.3%) were new, occurred during competition (n=954, 86%) and led to 4-7 missed days in severity (n=429, 46%). Injury incidence was 37.2 injuries per 1000h of exposure. Over half of injuries were contact in mechanism (n=355, 51%). Most injuries were to the lower limb (n=720, 60%), with the thigh representing the highest proportion of these. This study provides key information as to the aetiology of injury in this level of competition and provides a stronger foundation from which injury prevention studies could be carried out. Future research is well-placed to develop an understanding of the injury risk factors in the elite junior cohort, whilst also reducing injury risk once players transition to the AFL. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Executive Functioning in Highly Talented Soccer Players

PubMed Central

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. PMID:24632735

Preseason screening of shoulder range of motion and humeral retrotorsion does not predict injury in high school baseball players.

PubMed

Oyama, Sakiko; Hibberd, Elizabeth E; Myers, Joseph B

2017-07-01

Shoulder and elbow injuries are commonplace in high school baseball. Although altered shoulder range of motion (ROM) and humeral retrotorsion angles have been associated with injuries, the efficacy of preseason screening of these characteristics remains controversial. We conducted preseason screenings for shoulder internal and external rotation ROM and humeral retrotorsion on 832 high school baseball players and tracked their exposure and incidence on throwing-related shoulder and elbow injuries during a subsequent season. Poisson regression with robust error variance was used to determine whether preseason screening could identify injury risk in baseball players and whether the injury risk was higher for pitchers compared with players who do not pitch. Shoulder rotation ROM or humeral retrotorsion at preseason did not predict the risk of throwing-related upper extremity injury (P = .15-.89). Injury risk was 3.84 higher for baseball players who pitched compared with those who did not (95% confidence interval, 1.72-8.56; P = .001). Preseason measures of shoulder ROM and humeral retrotorsion may not be effective in identifying players who are at increased injury risk. Because shoulder ROM is a measure that fluctuates under a variety of influences, future study should investigate whether taking multiple measurements during a season can identify at-risk players. The usefulness of preseason screening may also depend on rigor of participation in sports. Future studies should investigate how preseason shoulder characteristics and participation factors (ie, pitch count and frequency, competitive level, pitching in multiple leagues) interact to predict injury risk in baseball players. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Sexual and reproductive health and rights in the evolving post-2015 agenda: perspectives from key players from multilateral and related agencies in 2013.

PubMed

Brolan, Claire E; Hill, Peter S

2014-05-01

This paper reports the views of participants from key multilaterals and related agencies in the evolving global negotiations on the post-2015 development agenda on the strategic location of sexual and reproductive health and rights. The research was carried out in June and July 2013, following the release of the report of the High-Level Panel of Eminent Persons on the Post-2015 Development Agenda, and comprised 40 semi-structured interviews with 57 participants and two e-mail respondents. All respondents were responsible for the post-2015 health and development agenda, or the post-2015 agenda more broadly, within their organisations. The interviews provide an insight into the intention to ensure that sexual and reproductive health and rights are integrated into the post-2015 trajectory by key players who sit at the interface of UN and Member State interaction. They reveal both an awareness of the shortcomings of the Millennium Development Goal process and its impact on advocacy for sexual and reproductive health and rights in early post-2015 engagement, as well as the vulnerability of sexual and reproductive health and rights in the remaining phases of post-2015 negotiations. Recent events bear these concerns out. Ensuring sexual and reproductive health and rights are included in the final post-2015 outcome document in the time remaining for negotiations, will be anything but a "doddle". Copyright © 2014 Reproductive Health Matters. Published by Elsevier Ltd. All rights reserved.

Tracing a key player in the regulation of plant architecture: the columnar growth habit of apple trees (Malus × domestica).

PubMed

Petersen, Romina; Krost, Clemens

2013-07-01

Plant architecture is regulated by a complex interplay of some key players (often transcription factors), phytohormones and other signaling molecules such as microRNAs. The columnar growth habit of apple trees is a unique form of plant architecture characterized by thick and upright stems showing a compaction of internodes and carrying short fruit spurs instead of lateral branches. The molecular basis for columnar growth is a single dominant allele of the gene Columnar, whose identity, function and gene product are unknown. As a result of marker analyses, this gene has recently been fine-mapped to chromosome 10 at 18.51-19.09 Mb [according to the annotation of the apple genome by Velasco (2010)], a region containing a cluster of quantitative trait loci associated with plant architecture, but no homologs to the well-known key regulators of plant architecture. Columnar apple trees have a higher auxin/cytokinin ratio and lower levels of gibberellins and abscisic acid than normal apple trees. Transcriptome analyses corroborate these results and additionally show differences in cell membrane and cell wall function. It can be expected that within the next year or two, an integration of these different research methodologies will reveal the identity of the Columnar gene. Besides enabling breeders to efficiently create new apple (and maybe related pear, peach, cherry, etc.) cultivars which combine desirable characteristics of commercial cultivars with the advantageous columnar growth habit using gene technology, this will also provide new insights into an elevated level of plant growth regulation.

Clustering performances in the NBA according to players' anthropometric attributes and playing experience.

PubMed

Zhang, Shaoliang; Lorenzo, Alberto; Gómez, Miguel-Angel; Mateus, Nuno; Gonçalves, Bruno; Sampaio, Jaime

2018-04-20

The aim of this study was: (i) to group basketball players into similar clusters based on a combination of anthropometric characteristics and playing experience; and (ii) explore the distribution of players (included starters and non-starters) from different levels of teams within the obtained clusters. The game-related statistics from 699 regular season balanced games were analyzed using a two-step cluster model and a discriminant analysis. The clustering process allowed identifying five different player profiles: Top height and weight (HW) with low experience, TopHW-LowE; Middle HW with middle experience, MiddleHW-MiddleE; Middle HW with top experience, MiddleHW-TopE; Low HW with low experience, LowHW-LowE; Low HW with middle experience, LowHW-MiddleE. Discriminant analysis showed that TopHW-LowE group was highlighted by two-point field goals made and missed, offensive and defensive rebounds, blocks, and personal fouls; whereas the LowHW-LowE group made fewest passes and touches. The players from weaker teams were mostly distributed in LowHW-LowE group, whereas players from stronger teams were mainly grouped in LowHW-MiddleE group; and players that participated in the finals were allocated in the MiddleHW-MiddleE group. These results provide alternative references for basketball staff concerning the process of evaluating performance.

Bennett lesions in baseball players detected by magnetic resonance imaging: assessment of association factors.

PubMed

Park, Jin-Young; Noh, Young-Min; Chung, Seok-Won; Moon, Sung-Gyn; Ha, Dae-Ho; Lee, Ki-Sun; Chung, Seok Won

2016-05-01

The purpose of this study was to evaluate the characteristics of Bennett lesions in baseball players compared with those without a Bennett lesion and to identify other possible factors associated with Bennett lesions on magnetic resonance imaging (MRI). We investigated 388 male baseball players with a career >1 year. Demographic factors and a routine physical examination, including glenohumeral internal rotation difference, scapular dyskinesis, and various pathologic changes, were reviewed on MRI to identify relative factors for Bennett lesions. Of the 388 patients evaluated, 125 (32.2%) were diagnosed with Bennett lesions of the shoulder. No significant differences were observed between the groups in demographic factors, physical examination results, visual analog scale score, American Shoulder and Elbow Surgeons score, or prevalence of concomitant diseases. However, players with Bennett lesions had played baseball longer than those without the lesions (P < .001). An association was found between Bennett lesions and the length of time that a patient with a Bennett lesion had played baseball. The prevalence of pathologic lesions detected on MRI and the physical examination results were not different between players with and without Bennett lesions. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Drug quality in South Africa: perceptions of key players involved in medicines distribution.

PubMed

Patel, Aarti; Norris, Pauline; Gauld, Robin; Rades, Thomas

2009-01-01

Substandard medicines contribute to poor public health and affect development, especially in the developing world. However knowledge of how manufacturers, distributors and providers understand the concept of drug quality and what strategies they adopt to ensure drug quality is limited, particularly in the developing world. The purpose of this paper is to explore pharmaceutical manufacturers', distributors' and providers' perceptions of drug quality in South Africa and how they ensure the quality of drugs during the distribution process. The approach taken was qualitative data collection through key informant interviews using a semi-structured interview guide. Transcripts were analysed thematically in Johannesburg, Pretoria and Durban, South Africa. Participants were recruited purposefully from a South African pharmaceutical manufacturer, SA subsidiaries of international manufacturers, national distribution companies, national wholesaler, public and private sector pharmacists, and a dispensing doctor. In total, ten interviews were conducted. Participants described drug quality in terms of the product and the processes involved in manufacturing and handling the product. Participants identified purchasing registered medicines from licensed suppliers, use of standard operating procedures, and audits between manufacturer and distributor and/or provider as key strategies employed to protect medicine quality. Effective communication amongst all stakeholders, especially in terms of providing feedback regarding complaints about medicine quality, appears as a potential area of concern, which would benefit from further research. The paper hightlights that ensuring medicine quality should be a shared responsibility amongst all involved in the distribution process to prevent medicines moving from one distribution system (public) into another (private).

Integrative Analysis of DNA Methylation and Gene Expression Data Identifies EPAS1 as a Key Regulator of COPD

PubMed Central

Yoo, Seungyeul; Takikawa, Sachiko; Geraghty, Patrick; Argmann, Carmen; Campbell, Joshua; Lin, Luan; Huang, Tao; Tu, Zhidong; Feronjy, Robert; Spira, Avrum; Schadt, Eric E.; Powell, Charles A.; Zhu, Jun

2015-01-01

Chronic Obstructive Pulmonary Disease (COPD) is a complex disease. Genetic, epigenetic, and environmental factors are known to contribute to COPD risk and disease progression. Therefore we developed a systematic approach to identify key regulators of COPD that integrates genome-wide DNA methylation, gene expression, and phenotype data in lung tissue from COPD and control samples. Our integrative analysis identified 126 key regulators of COPD. We identified EPAS1 as the only key regulator whose downstream genes significantly overlapped with multiple genes sets associated with COPD disease severity. EPAS1 is distinct in comparison with other key regulators in terms of methylation profile and downstream target genes. Genes predicted to be regulated by EPAS1 were enriched for biological processes including signaling, cell communications, and system development. We confirmed that EPAS1 protein levels are lower in human COPD lung tissue compared to non-disease controls and that Epas1 gene expression is reduced in mice chronically exposed to cigarette smoke. As EPAS1 downstream genes were significantly enriched for hypoxia responsive genes in endothelial cells, we tested EPAS1 function in human endothelial cells. EPAS1 knockdown by siRNA in endothelial cells impacted genes that significantly overlapped with EPAS1 downstream genes in lung tissue including hypoxia responsive genes, and genes associated with emphysema severity. Our first integrative analysis of genome-wide DNA methylation and gene expression profiles illustrates that not only does DNA methylation play a ‘causal’ role in the molecular pathophysiology of COPD, but it can be leveraged to directly identify novel key mediators of this pathophysiology. PMID:25569234

Integrative analysis of DNA methylation and gene expression data identifies EPAS1 as a key regulator of COPD.

PubMed

Yoo, Seungyeul; Takikawa, Sachiko; Geraghty, Patrick; Argmann, Carmen; Campbell, Joshua; Lin, Luan; Huang, Tao; Tu, Zhidong; Foronjy, Robert F; Feronjy, Robert; Spira, Avrum; Schadt, Eric E; Powell, Charles A; Zhu, Jun

2015-01-01

Chronic Obstructive Pulmonary Disease (COPD) is a complex disease. Genetic, epigenetic, and environmental factors are known to contribute to COPD risk and disease progression. Therefore we developed a systematic approach to identify key regulators of COPD that integrates genome-wide DNA methylation, gene expression, and phenotype data in lung tissue from COPD and control samples. Our integrative analysis identified 126 key regulators of COPD. We identified EPAS1 as the only key regulator whose downstream genes significantly overlapped with multiple genes sets associated with COPD disease severity. EPAS1 is distinct in comparison with other key regulators in terms of methylation profile and downstream target genes. Genes predicted to be regulated by EPAS1 were enriched for biological processes including signaling, cell communications, and system development. We confirmed that EPAS1 protein levels are lower in human COPD lung tissue compared to non-disease controls and that Epas1 gene expression is reduced in mice chronically exposed to cigarette smoke. As EPAS1 downstream genes were significantly enriched for hypoxia responsive genes in endothelial cells, we tested EPAS1 function in human endothelial cells. EPAS1 knockdown by siRNA in endothelial cells impacted genes that significantly overlapped with EPAS1 downstream genes in lung tissue including hypoxia responsive genes, and genes associated with emphysema severity. Our first integrative analysis of genome-wide DNA methylation and gene expression profiles illustrates that not only does DNA methylation play a 'causal' role in the molecular pathophysiology of COPD, but it can be leveraged to directly identify novel key mediators of this pathophysiology.

Daily Fantasy Sports Players: Gambling, Addiction, and Mental Health Problems.

PubMed

Nower, Lia; Caler, Kyle R; Pickering, Dylan; Blaszczynski, Alex

2018-01-19

Studies point to a relationship between fantasy sports/daily fantasy sports (DFS) play and gambling behavior. However, little is known about the nature of those relationships, particularly regarding the development of gambling problems. This study investigates the nature, frequency, and preferences of gambling behavior as well as problem gambling severity and comorbid conditions among DFS players. Data were collected from an epidemiologic survey of 3634 New Jersey residents on gambling and leisure activities. Participants were contacted by phone (land-line and cell) and online to obtain a representative, cross-sectional sample of non-institutionalized adults, aged 18 years or older. Excluding non-gamblers, the remaining 2146 participants, included in these analyses, indicated they had either played DFS (n = 299) or had gambled but not played DFS (1847) in the past year. Univariate comparisons and multiple logistic regression analyses were performed to identify the most significant characteristics and predictors of DFS players. Overall, a higher number of gambling activities, high frequency gambling, male gender, and reports of suicidal thoughts in the past year were most predictive of DFS players. Being Hispanic (vs. Caucasian) and/or single (vs. married or living with a partner) also doubled the odds of DFS play. Findings suggest that DFS players are characterized by high gambling frequency and problem severity and comorbid problems, notably suicidal ideation. Future research should examine the motivations and possible etiological sub-types of DFS players and the nature and course of DFS play, particularly in relation to gambling behavior and the development of gambling and other problems.

Etiology and Biomechanics of Tarsometatarsal Injuries in Professional Football Players

PubMed Central

Kent, Richard W.; Lievers, W. Brent; Riley, Patrick O.; Frimenko, Rebecca E.; Crandall, Jeff R.

2014-01-01

Background: Tarsometatarsal (TMT) dislocations are uncommon yet debilitating athletic injuries, particularly in American football. To date, the mechanisms of athletic TMT dislocation have been described only anecdotally. This lack of information confounds the development of preventative countermeasures. Purpose: To use video analysis to provide direct, independent identification of the etiologic and mechanistic variables responsible for TMT dislocations in professional football players. Study Design: Case series; Level of evidence, 4. Methods: Sixteen professional National Football League players who sustained publicly reported TMT dislocations were identified. Publicly broadcast game footage of the plays in which injury occurred was reviewed by a panel of 5 biomechanists. Consensus was reached regarding the details surrounding injury, and a weighting was assigned to each detail based on the panel’s confidence. Results: Roughly 90% of injuries occurred while the injured player was engaged with or by another player, a detail that has heretofore been undocumented. Few injuries resulted from direct loading of either the foot or the ipsilateral limb; however, the injured foot was frequently subjected to axial loading from ground engagement with the foot in plantar flexion and the toes dorsiflexed. Injurious loading was often due to external rotation of the midfoot (86%). Fifteen of 16 injuries were season ending. Conclusion: TMT dislocations are frequently associated with engagement by or with a second player but infrequently caused by a direct blow to the foot. Axial loading of the foot, external rotation, and pronation/supination are the most common conditions during injurious loading. PMID:26535306

Replicator dynamics with turnover of players

NASA Astrophysics Data System (ADS)

Juul, Jeppe; Kianercy, Ardeshir; Bernhardsson, Sebastian; Pigolotti, Simone

2013-08-01

We study adaptive dynamics in games where players abandon the population at a given rate and are replaced by naive players characterized by a prior distribution over the admitted strategies. We demonstrate how such a process leads macroscopically to a variant of the replicator equation, with an additional term accounting for player turnover. We study how Nash equilibria and the dynamics of the system are modified by this additional term for prototypical examples such as the rock-paper-scissors game and different classes of two-action games played between two distinct populations. We conclude by showing how player turnover can account for nontrivial departures from Nash equilibria observed in data from lowest unique bid auctions.

Randomness in nonlocal games between mistrustful players

PubMed Central

Miller, Carl A.; Shi, Yaoyun

2017-01-01

If two quantum players at a nonlocal game G achieve a superclassical score, then their measurement outcomes must be at least partially random from the perspective of any third player. This is the basis for device-independent quantum cryptography. In this paper we address a related question: does a superclassical score at G guarantee that one player has created randomness from the perspective of the other player? We show that for complete-support games, the answer is yes: even if the second player is given the first player’s input at the conclusion of the game, he cannot perfectly recover her output. Thus some amount of local randomness (i.e., randomness possessed by only one player) is always obtained when randomness is certified from nonlocal games with quantum strategies. This is in contrast to non-signaling game strategies, which may produce global randomness without any local randomness. We discuss potential implications for cryptographic protocols between mistrustful parties. PMID:29643748

Developmental activities and the acquisition of superior anticipation and decision making in soccer players.

PubMed

Roca, André; Williams, A Mark; Ford, Paul R

2012-01-01

We examined whether soccer players with varying levels of perceptual-cognitive expertise can be differentiated based on their engagement in various types and amounts of activity during their development. A total of 64 participants interacted with life-size video clips of 11 versus 11 dynamic situations in soccer, viewed from the first-person perspective of a central defender. They were required to anticipate the actions of their opponents and to make appropriate decisions as to how best to respond. Response accuracy scores were used to categorise elite players (n = 48) as high- (n = 16) and low-performing (n = 16) participants. A group of recreational players (n = 16) who had lower response accuracy scores compared to the elite groups acted as controls. The participation history profiles of players were recorded using retrospective recall questionnaires. The average hours accumulated per year during childhood in soccer-specific play activity was the strongest predictor of perceptual-cognitive expertise. Soccer-specific practice activity during adolescence was also a predictor, albeit its impact was relatively modest. No differences were reported across groups for number of other sports engaged in during development, or for some of the key milestones achieved. A number of implications for talent development are discussed.

Rehabilitation protocol for patellar tendinopathy applied among 16- to 19-year old volleyball players.

PubMed

Biernat, Ryszard; Trzaskoma, Zbigniew; Trzaskoma, Lukasz; Czaprowski, Dariusz

2014-01-01

The aim of the study was to investigate the efficacy of rehabilitation protocol applied during competitive period for the treatment of patellar tendinopathy. A total of 28 male volleyball players were divided into two groups. Fifteen from experimental group (E) and 13 from control group (C) fulfilled the same tests 3 times: before the training program started (first measurement), after 12 weeks (second measurement) and after 24 weeks (third measurement). The above-mentioned protocol included the following: USG imagining with color Doppler function, clinical testing, pain intensity evaluation with VISA-P questionnaire, leg muscle strength and power and jumping ability measurements. The key element of the rehabilitation program was eccentric squat on decline board with additional unstable surface. The essential factor of the protocol was a set of preventive functional exercises, with focus on eccentric exercises of hamstrings. Patellar tendinopathy was observed in 18% of the tested young volleyball players. Implementation of the presented rehabilitation protocol with eccentric squat on decline board applied during sports season lowered the pain level of the young volleyball players. Presented rehabilitation protocol applied without interrupting the competitive period among young volleyball players together with functional exercises could be an effective method for the treatment of patellar tendinopathy.

Kinematics of Shooting in High School and Collegiate Lacrosse Players With and Without Low Back Pain.

PubMed

Wasser, Joseph G; Chen, Cong; Vincent, Heather K

2016-07-01

Low back pain (LBP) and motion alterations can occur in athletes who engage in high-speed throwing motions. The relationship between LBP and shooting motion in lacrosse players is not yet known. To quantify the effects of LBP on key kinematic parameters of the lacrosse shot and determine the contribution of the severity of LBP on specific kinematic parameters of the shooting motion. Controlled laboratory study. High school and collegiate players (N = 24) were stratified into 2 groups based on back pain symptoms (LBP or no pain). Three-dimensional motion capture of overhead throws was used to collect data on knee, pelvis, trunk, and shoulder kinematics as well as crosse stick (the stick capped with a strung net) and ball speed. Mean low back numeric pain rating scale (NRSpain) score was 2.9. Knee flexion at ball release was greater in the LBP than no pain group, indicating a more bent knee (P = .04). The LBP group demonstrated less angular velocity transfer from pelvis to trunk than the no pain group (P = .05). Total range of motion of the pelvis and shoulders during the shot and follow-through were less in the LBP group than the no pain group (83.6° ± 24.5° vs 75.9° ± 24.5°, P = .05). Age- and sex-adjusted regression analyses revealed that the low back NRSpain rating contributed 6.3% to 25.0% of the variance to the models of shoulder transverse rotation range of motion, trunk and shoulder rotation angular velocities, and knee flexion angle (P < .05). LBP severity significantly contributes to trunk and shoulder motion restriction during lacrosse shooting. Inclusion of lumbopelvic and core training and prehabilitation programs for high school and collegiate players may reduce pain in affected players as well as help them to attain appropriate motion parameters and avoid secondary musculoskeletal injuries. This research identified a prehabilitation need in the understudied lacrosse population. Therapeutic strategies can be developed to strengthen the throwing

Do "big guys" really die younger? An examination of height and lifespan in former professional basketball players.

PubMed

Lemez, Srdjan; Wattie, Nick; Baker, Joseph

2017-01-01

While factors such as genetics may mediate the relationship between height and mortality, evidence suggests that larger body size may be an important risk indicator of reduced lifespan longevity in particular. This study critically examined this relationship in professional basketball players. We examined living and deceased players who have played in the National Basketball Association (debut between 1946-2010) and/or the American Basketball Association (1967-1976) using descriptive and Kaplan-Meier and Cox regression analyses. The cut-off date for death data collection was December 11, 2015. Overall, 3,901 living and deceased players were identified and had a mean height of 197.78 cm (± 9.29, Range: 160.02-231.14), and of those, 787 former players were identified as deceased with a mean height of 193.88 cm (± 8.83, Range: 167.6-228.6). Descriptive findings indicated that the tallest players (top 5%) died younger than the shortest players (bottom 5%) in all but one birth decade (1941-1950). Similarly, survival analyses showed a significant relationship between height and lifespan longevity when both dichotomizing [χ2 (1) = 13.04, p < .05] and trichotomizing [χ2 (2) = 18.05, p < .05] the predictor variable height per birth decade, where taller players had a significantly higher mortality risk compared to shorter players through median (HR: 1.30, 95% CI: 1.13-1.50, p < .05) and trichotomized tertile split (HR: 1.40, 95% CI: 1.18-1.68, p <. 05; tallest 33.3% compared to shortest 33.3%) analyses. The uniqueness of examining the height-longevity hypothesis in this relatively homogeneous sub-population should be considered when interpreting these results. Further understanding of the potential risks of early mortality can help generate discourse regarding potential at-risk cohorts of the athlete population.

Do "big guys" really die younger? An examination of height and lifespan in former professional basketball players

PubMed Central

2017-01-01

While factors such as genetics may mediate the relationship between height and mortality, evidence suggests that larger body size may be an important risk indicator of reduced lifespan longevity in particular. This study critically examined this relationship in professional basketball players. We examined living and deceased players who have played in the National Basketball Association (debut between 1946–2010) and/or the American Basketball Association (1967–1976) using descriptive and Kaplan-Meier and Cox regression analyses. The cut-off date for death data collection was December 11, 2015. Overall, 3,901 living and deceased players were identified and had a mean height of 197.78 cm (± 9.29, Range: 160.02–231.14), and of those, 787 former players were identified as deceased with a mean height of 193.88 cm (± 8.83, Range: 167.6–228.6). Descriptive findings indicated that the tallest players (top 5%) died younger than the shortest players (bottom 5%) in all but one birth decade (1941–1950). Similarly, survival analyses showed a significant relationship between height and lifespan longevity when both dichotomizing [χ2 (1) = 13.04, p < .05] and trichotomizing [χ2 (2) = 18.05, p < .05] the predictor variable height per birth decade, where taller players had a significantly higher mortality risk compared to shorter players through median (HR: 1.30, 95% CI: 1.13–1.50, p < .05) and trichotomized tertile split (HR: 1.40, 95% CI: 1.18–1.68, p <. 05; tallest 33.3% compared to shortest 33.3%) analyses. The uniqueness of examining the height-longevity hypothesis in this relatively homogeneous sub-population should be considered when interpreting these results. Further understanding of the potential risks of early mortality can help generate discourse regarding potential at-risk cohorts of the athlete population. PMID:28968418

Neuroplus biofeedback improves attention, resilience, and injury prevention in elite soccer players.

PubMed

Rusciano, Aiace; Corradini, Giuliano; Stoianov, Ivilin

2017-06-01

Performance and injury prevention in elite soccer players are typically investigated from physical-tactical, biomechanical, and metabolic perspectives. However, executive functions, visuospatial abilities, and psychophysiological adaptability or resilience are also fundamental for efficiency and well-being in sports. Based on previous research associating autonomic flexibility with prefrontal cortical control, we designed a novel integrated autonomic biofeedback training method called Neuroplus to improve resilience, visual attention, and injury prevention. Herein, we introduce the method and provide an evaluation of 20 elite soccer players from the Italian Soccer High Division (Serie-A): 10 players trained with Neuroplus and 10 trained with a control treatment. The assessments included psychophysiological stress profiles, a visual search task, and indexes of injury prevention, which were measured pre- and posttreatment. The analysis showed a significant enhancement of physiological adaptability, recovery following stress, visual selective attention, and injury prevention that were specific to the Neuroplus group. Enhancing the interplay between autonomic and cognitive functions through biofeedback may become a key principle for obtaining excellence and well-being in sports. To our knowledge, this is the first evidence that shows improvement in visual selective attention following intense autonomic biofeedback. © 2017 Society for Psychophysiological Research.

Shoulder injuries in adolescent rugby players

PubMed Central

Hodhody, Ghazal; Mackenzie, Tanya A

2016-01-01

Background Rugby is a high-intensity contact sport, frequently causing shoulder injuries. Between the ages of 12 years to 18 years, academy and county level players are being selected for professional contracts, making this is a critical stage of their career. The present study aimed to describe the patterns of injury in adolescent rugby players with shoulder injuries. Methods Academy and county level rugby players in the target age group, over a 7-year period, were included in the present study. Data collected included the mechanism of injury, position and level of play, radiology and surgical findings, and recurrence rate at a minimum of 2 years post-surgery. Results One hundred and sixty-nine cases adhered to the inclusion criteria, with most cases involving two or more pathologies in the shoulder (54%). Forwards sustained more shoulder injuries than backs, incurring more labral injuries. By contrast, backs had a higher incidence of bony pathology. The mechanism of injury frequently correlated with player positions. There was a 21% injury recurrence rate, with forwards (7%) and higher level academy players (11%) most likely to suffer a recurrence. Conclusions Shoulder injury patterns in this important group of adolescent contact athletes are complex, with recurrence rates being higher than those in older rugby players. PMID:27583014

The Prevalence of Injuries in Professional Turkish Soccer Players

ERIC Educational Resources Information Center

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…

Anthropometric and performance comparisons in professional baseball players.

PubMed

Hoffman, Jay R; Vazquez, Jose; Pichardo, Napoleon; Tenenbaum, Gershon

2009-11-01

This study compared anthropometric and performance variables in professional baseball players and examined the relationship between these variables and baseball-specific performance (i.e., home runs, total bases, slugging percentage, and stolen bases). During a 2-year period, 343 professional baseball players were assessed for height, weight, body composition, grip strength, vertical jump power, 10-yard sprint speed, and agility. Subject population consisted of players on the rosters of one of the minor league affiliates (Rookie, A, AA, AAA) or major league team (MLB). All testing occurred at the beginning of spring training. Players in Rookie and A were significantly (p < 0.05) leaner than players in MLB and AAA. These same players had significantly lower lean body mass than seen in MLB, AAA, and AA players. Greater grip strength (p < 0.05) was seen in MLB and AAA than in Rookie and A. Players in MLB were also faster (p < 0.05) than players in AA, A, and Rookie. Vertical jump power measures were greater (p < 0.05) in MLB than AA, A, and Rookie. Regression analysis revealed that performance measures accounted for 25-31% of the variance in baseball-specific power performance. Anthropometric measures failed to add any additional explanation to the variance in these baseball-specific performance variables. Results indicated that both anthropometric and performance variables differed between players of different levels of competition in professional baseball. Agility, speed, and lower-body power appeared to provide the greatest predictive power of baseball-specific performance.

Dominant-limb range-of-motion and humeral-retrotorsion adaptation in collegiate baseball and softball position players.

PubMed

Hibberd, Elizabeth E; Oyama, Sakiko; Tatman, Justin; Myers, Joseph B

2014-01-01

Biomechanically, the motions used by baseball and softball pitchers differ greatly; however, the throwing motions of position players in both sports are strikingly similar. Although the adaptations to the dominant limb from overhead throwing have been well documented in baseball athletes, these adaptations have not been clearly identified in softball players. This information is important in order to develop and implement injury-prevention programs specific to decreasing the risk of upper extremity injury in softball athletes. To compare range-of-motion and humeral-retrotorsion characteristics of collegiate baseball and softball position players and of baseball and softball players to sex-matched controls. Cross-sectional study. Research laboratories and athletic training rooms at the University of North Carolina at Chapel Hill. Fifty-three collegiate baseball players, 35 collegiate softball players, 25 male controls (nonoverhead athletes), and 19 female controls (nonoverhead athletes). Range of motion and humeral retrotorsion were measured using a digital inclinometer and diagnostic ultrasound. Glenohumeral internal-rotation deficit, external-rotation gain, total glenohumeral range of motion, and humeral retrotorsion. Baseball players had greater glenohumeral internal-rotation deficit, total-range-of-motion, and humeral-retrotorsion difference than softball players and male controls. There were no differences between glenohumeral internal-rotation deficit, total-range-of-motion, and humeral-retrotorsion difference in softball players and female controls. Few differences were evident between softball players and female control participants, although range-of-motion and humeral-retrotorsion adaptations were significantly different than baseball players. The throwing motions are similar between softball and baseball, but the athletes adapt to the demands of the sport differently; thus, stretching/strengthening programs designed for baseball may not be the most

Hack-proof Synchronization Protocol for Multi-player Online Games

NASA Astrophysics Data System (ADS)

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.

Comparing Performance During Morning vs. Afternoon Training Sessions in Intercollegiate Basketball Players

PubMed Central

Heishman, Aaron D.; Curtis, Michael A.; Saliba, Ethan N.; Hornett, Robert J.; Malin, Steven K.

2017-01-01

Abstract Heishman, AD, Curtis, MA, Saliba, EN, Hornett, RJ, Malin, SK, and Weltman, AL. Comparing performance during morning vs. afternoon training sessions in intercollegiate basketball players. J Strength Cond Res 31(6): 1557–1562, 2017—Time of day is a key factor that influences the optimization of athletic performance. Intercollegiate coaches oftentimes hold early morning strength training sessions for a variety of factors including convenience. However, few studies have specifically investigated the effect of early morning vs. late afternoon strength training on performance indices of fatigue. This is athletically important because circadian and/or ultradian rhythms and alterations in sleep patterns can affect training ability. Therefore, the purpose of the present study was to examine the effects of morning vs. afternoon strength training on an acute performance index of fatigue (countermovement jump height, CMJ), player readiness (Omegawave), and self-reported sleep quantity. We hypothesized that afternoon training sessions would be associated with increased levels of performance, readiness, and self-reported sleep. A retrospective analysis was performed on data collected over the course of the preseason on 10 elite National Collegiate Athletic Association Division 1 male basketball players. All basketball-related activities were performed in the afternoon with strength and conditioning activities performed either in the morning or in the afternoon. The average values for CMJ, power output (Power), self-reported sleep quantity (sleep), and player readiness were examined. When player load and duration were matched, CMJ (58.8 ± 1.3 vs. 61.9 ± 1.6 cm, p = 0.009), Power (6,378.0 ± 131.2 vs. 6,622.1 ± 172.0 W, p = 0.009), and self-reported sleep duration (6.6 ± 0.4 vs. 7.4 ± 0.25 p = 0.016) were significantly higher with afternoon strength and conditioning training, with no differences observed in player readiness values. We conclude that performance is

Risk factors for shoulder and elbow pain in youth baseball players.

PubMed

Matsuura, Tetsuya; Iwame, Toshiyuki; Suzue, Naoto; Arisawa, Kokichi; Sairyo, Koichi

2017-05-01

This study sought to quantify the 1-year cumulative incidence of shoulder and elbow pain among youth baseball players and identify risk factors associated with the occurrence of shoulder and elbow pain. In total, 900 youth baseball players (aged 7-11 years) were enrolled in a 1-year prospective follow-up study. One year later, the players were asked whether they had experienced episodes of shoulder or elbow pain and the following risk factors for such pain were investigated: age, position, length of baseball experience, training hours per week, and history of shoulder or elbow pain. Data for the groups with and without shoulder or elbow pain were analyzed using multivariate logistic regression models. Episodes of shoulder pain were reported by 18.3% of players and episodes of elbow pain were reported by 35.2% of players. Multivariate analysis showed that shoulder pain was associated with pitcher position, catcher position, longer training hours per week, and history of shoulder and elbow pain, and that elbow pain was associated with age, pitcher position, catcher position, longer training hours per week, and history of elbow pain. Length of baseball experience was not associated with shoulder or elbow pain. History of elbow pain, pitcher position, catcher position, and longer training hours per week were associated with both types of pain. History of shoulder pain was associated with shoulder pain but not elbow pain. Age was associated with elbow pain but not shoulder pain.

Explosive Strength Imbalances in Professional Basketball Players

PubMed Central

Schiltz, Marc; Lehance, Cédric; Maquet, Didier; Bury, Thierry; Crielaard, Jean-Michel; Croisier, Jean-Louis

2009-01-01

Context: Despite the high rate of lower limb injuries in basketball players, studies of the dominant-limb effect in elite athletes often neglect injury history. Objective: To determine lower limb explosive-strength asymmetries in professional basketball players compared with junior basketball players and control participants. Design: Cohort study. Setting: Academic medical institution. Patients or Other Participants: 15 professional basketball players, 10 junior basketball players, and 20 healthy men. Main Outcome Measure(s): We performed an isokinetic examination to evaluate the knee extensor (Ext) and flexor (Fl) concentric peak torque at 60°·s−1 and 240°·s−1 and (Fl only) eccentric peak torque at 30°·s−1 and 120°·s−1. Functional evaluation included countermovement jump, countermovement jump with arms, 10-m sprint, single-leg drop jump, and single-leg, 10-second continuous jumping. Variables were compared among groups using analysis of variance or a generalized linear mixed model for bilateral variables. Results: The 2 groups of basketball players demonstrated better isokinetic and functional performances than the control group did. No differences in functional or relative isokinetic variables were noted between professional and junior basketball players. Professional players with a history of knee injury failed to reach normal knee extensor strength at 60°·s−1. Knee Ext (60°·s−1) and Fl (eccentric 120°·s−1) torque values as well as 10-second continuous jumping scores were higher in those professional players without a history of knee injury than those with such a history. Compared with the group without a history of knee injury, the group with a history of knee injury maintained leg asymmetry ratios greater than 10% for almost all isokinetic variables and more than 15% for unilateral functional variables. Conclusions: The relative isokinetic and functional performances of professional basketball players were similar to those of junior

Soccer Players Cultural Capital and Its Impact on Migration

PubMed Central

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

Altering the Speed Profiles of Wheelchair Rugby Players With Game-Simulation Drill Design.

PubMed

Rhodes, James M; Mason, Barry S; Paulson, Thomas A W; Goosey-Tolfrey, Victoria L

2018-01-01

To examine the speed profiles of elite wheelchair rugby (WCR) players during game-simulation training drills of differing player number and shot-clock regulations. A secondary aim was to determine whether the profiles were further influenced by player classification. Eight elite WCR players (low-point n = 3, high-point n = 5) were monitored using a radio-frequency-based indoor tracking system during training sessions over a 5-mo period. Speed profiles were collected for 3 modified game-simulation drills-3-versus-3 drills (n = 8 observations), 30-s shot clock (n = 24 observations), and 15-s shot clock (n = 16 observations)-and were compared with regular game-simulation drills (4 vs 4, 40-s shot clock; n = 16 observations). Measures included mean and peak speed; exercise-intensity ratios, defined as the ratio of time spent performing at high and low speeds; and the number of high-speed activities performed. Compared with regular game-simulation drills, 3-versus-3 drills elicited a moderate increase in mean speed (6.3%; effect size [ES] = 0.7) and the number of high-speed activities performed (44.1%; ES = 1.1). Minimal changes in speed profiles were observed during the 30-s shot clock, although moderate to large increases in all measures were observed during the 15-s shot-clock drills. Classification-specific differences were further identified, with increased activity observed for high-point players during the 3-versus-3 drill and for low-point players during the 15-s shot clock. By reducing the number of players on court and the shot clock to 15 s, coaches can significantly increase elite WCR players' speed profiles during game-simulation drills.

Competition-Level Differences on the Lower Quarter Y-Balance Test in Baseball Players

PubMed Central

Butler, Robert J.; Bullock, Garrett; Arnold, Todd; Plisky, Phillip; Queen, Robin

2016-01-01

Context: Decreased performance in dynamic balance has previously been associated with a history of ulnar collateral ligament injury in baseball players. Previous research on dynamic balance in soccer players has shown that test performance depends on competition level. However, dynamic balance has yet to be examined in baseball players. Objective: To understand normative values and determine differences in dynamic balance, as measured by the Lower Quarter Y-Balance Test, across competition levels in baseball players. Design: Cross-sectional study. Setting: Preseason physical examinations. Patients or Other Participants: Dynamic balance was measured in 88 high school (HS), 78 collegiate (COL), and 90 professional (PRO) baseball players. Main Outcome Measure(s): All participants completed the Lower Quarter Y-Balance Test using the standard protocol. In unilateral stance, they reached with 1 foot in the anterior, posteromedial, and posterolateral directions. We calculated 1-way analyses of variance to compare performance, composite score, and reach asymmetry for each direction as well as the sum of the asymmetry values (P < .05). Composite score was calculated by averaging the maximum normalized reach scores. Reach asymmetry was determined by calculating bilateral differences in reach ability. Results: In comparison with the HS and COL groups, the PRO players exhibited greater posteromedial (P < .01; effect size index [ESI]HS = 1.06, ESICOL = 0.95) and posterolateral reach (P < .01; ESIHS = 0.82, ESICOL = 0.84) as well as a greater composite score (P < .01; ESIHS = 0.60, ESICOL = 0.87). In contrast, HS baseball players exhibited increased anterior reach (P < .01; ESICOL = 0.60, ESIPRO = 0.39) compared with the COL and PRO cohorts. No significant differences in reach asymmetry were observed among groups. Conclusions: Lower extremity dynamic balance performance differed based on the baseball players' competition level. These baseline data may be helpful in identifying

Competition-Level Differences on the Lower Quarter Y-Balance Test in Baseball Players.

PubMed

Butler, Robert J; Bullock, Garrett; Arnold, Todd; Plisky, Phillip; Queen, Robin

2016-12-01

Decreased performance in dynamic balance has previously been associated with a history of ulnar collateral ligament injury in baseball players. Previous research on dynamic balance in soccer players has shown that test performance depends on competition level. However, dynamic balance has yet to be examined in baseball players. To understand normative values and determine differences in dynamic balance, as measured by the Lower Quarter Y-Balance Test, across competition levels in baseball players. Cross-sectional study. Preseason physical examinations. Dynamic balance was measured in 88 high school (HS), 78 collegiate (COL), and 90 professional (PRO) baseball players. All participants completed the Lower Quarter Y-Balance Test using the standard protocol. In unilateral stance, they reached with 1 foot in the anterior, posteromedial, and posterolateral directions. We calculated 1-way analyses of variance to compare performance, composite score, and reach asymmetry for each direction as well as the sum of the asymmetry values (P < .05). Composite score was calculated by averaging the maximum normalized reach scores. Reach asymmetry was determined by calculating bilateral differences in reach ability. In comparison with the HS and COL groups, the PRO players exhibited greater posteromedial (P < .01; effect size index [ESI] HS = 1.06, ESI COL = 0.95) and posterolateral reach (P < .01; ESI HS = 0.82, ESI COL = 0.84) as well as a greater composite score (P < .01; ESI HS = 0.60, ESI COL = 0.87). In contrast, HS baseball players exhibited increased anterior reach (P < .01; ESI COL = 0.60, ESI PRO = 0.39) compared with the COL and PRO cohorts. No significant differences in reach asymmetry were observed among groups. Lower extremity dynamic balance performance differed based on the baseball players' competition level. These baseline data may be helpful in identifying low-performing athletes who might benefit from neuromuscular interventions.

RM-DEMATEL: a new methodology to identify the key factors in PM2.5.

PubMed

Chen, Yafeng; Liu, Jie; Li, Yunpeng; Sadiq, Rehan; Deng, Yong

2015-04-01

Weather system is a relative complex dynamic system, the factors of the system are mutually influenced PM2.5 concentration. In this paper, a new method is proposed to quantify the influence on PM2.5 by other factors in the weather system and identify the most important factors for PM2.5 with limited resources. The relation map (RM) is used to figure out the direct relation matrix of 14 factors in PM2.5. The decision making trial and evaluation laboratory(DEMATEL) is applied to calculate the causal relationship and extent to a mutual influence of 14 factors in PM2.5. According to the ranking results of our proposed method, the most important key factors is sulfur dioxide (SO2) and nitrogen oxides (NO(X)). In addition, the other factors, the ambient maximum temperature (T(max)), concentration of PM10, and wind direction (W(dir)), are important factors for PM2.5. The proposed method can also be applied to other environment management systems to identify key factors.

Utility of S100B Serum Level for the Determination of Concussion in Male Rugby Players.

PubMed

Bouvier, Damien; Duret, Thomas; Abbot, Mathieu; Stiernon, Thibault; Pereira, Bruno; Coste, Aurélien; Chazal, Jean; Sapin, Vincent

2017-04-01

The incidence of concussion in professional direct-contact sports, particularly in rugby, has increased in recent years. To date, cognitive assessment is the most common means of determining whether a concussed player can return to the game. Serum S100B assay, an objective blood test known to be useful in brain injury management, may offer a novel additional approach to the management of concussed male rugby players. The aim of this study was to investigate the S100B utility for the determination of concussion in a professional 15-players-a-side rugby team. Thirty-nine male rugby players were included in a prospective study during the 2014-2015 French championship season. Serum sampling was carried out several times at baseline and after a match and/or a concussion, at set times (2, 36 h). Serum S100B concentrations were determined using chemiluminescence immunoassay on a Roche Diagnostics ® instrument. The players' basal serum S100B was stable during the season and was not correlated with anthropometric data, body composition, or creatine kinase concentration. A significant increase in S100B concentration within 2 h after a game (without concussion) was observed. This increase was correlated with the number of body collisions during a match. Seventy-seven assays were performed 36 h after a game, including the follow-up of five concussed players. Thirty-six hours after a match, an increase of a minimum of 20 % compared with individual basal concentrations identified concussion with 100 % sensitivity and 81 % specificity. S100B measured 36 h after a match is thus a discriminating test to identify concussion in a male rugby player, with a 100 % negative predictive value.

Predictors of perceptions of mental illness and averseness to help: a survey of elite football players.

PubMed

Jones, Tiffanie-Victoria

2016-10-01

Hypermasculinity may impact elite football players' willingness to seek help for mental health problems. This quantitative study sought to identify what set of characteristics, including hypermasculinity, best predicts elite football players' mental health attitudes. The Attitude Scale for Mental Illness, Inventory of Attitudes toward Seeking Mental Health Services, and Athlete's Perception of Masculinity Scale were self-administered to 112 football players from the NFLPA and the Washington, DC metro area. Canonical correlation analysis was used to develop a regression model that best predicts elite football players' mental health attitudes. This study found that though the athletes have high levels of hypermasculinity (x = 19.66, SD = 7.43), other factors, including marital status and sport level lessen the effects of hypermasculinity and facilitate positive perceptions of mental illness and receptivity to help. Predictors suggest that therapeutic efforts targeted toward family and support networks, as well as intervention strategies for decreasing mental illness stigma are essential to encourage positive mental health attitudes in elite football players.

Head impact exposure sustained by football players on days of diagnosed concussion.

PubMed

Beckwith, Jonathan G; Greenwald, Richard M; Chu, Jeffrey J; Crisco, Joseph J; Rowson, Steven; Duma, Stefan M; Broglio, Steven P; McAllister, Thomas W; Guskiewicz, Kevin M; Mihalik, Jason P; Anderson, Scott; Schnebel, Brock; Brolinson, P Gunnar; Collins, Michael W

2013-04-01

This study compares the frequency and severity of head impacts sustained by football players on days with and without diagnosed concussion and to identify the sensitivity and specificity of single-impact severity measures to diagnosed injury. One thousand two hundred eight players from eight collegiate football teams and six high school football teams wore instrumented helmets to measure head impacts during all team sessions, of which 95 players were diagnosed with concussion. Eight players sustained two injuries and one sustained three, providing 105 injury cases. Measures of head kinematics (peak linear and rotational acceleration, Gadd severity index, head injury criteria (HIC15), and change in head velocity (Δv)) and the number of head impacts sustained by individual players were compared between days with and without diagnosed concussion. Receiver operating characteristic curves were generated to evaluate the sensitivity and specificity of each kinematic measure to diagnosed concussion using only those impacts that directly preceded diagnosis. Players sustained a higher frequency of impacts and impacts with more severe kinematic properties on days of diagnosed concussion than on days without diagnosed concussion. Forty-five injury cases were immediately diagnosed after head impact. For these cases, peak linear acceleration and HIC15 were most sensitive to immediately diagnosed concussion (area under the curve = 0.983). Peak rotational acceleration was less sensitive to diagnosed injury than all other kinematic measures (P = 0.01), which are derived from linear acceleration (peak linear, HIC15, Gadd severity index, and Δv). Players sustained more impacts and impacts of higher severity on days of diagnosed concussion than on days without diagnosed concussion. In addition, of historical measures of impact severity, those associated with peak linear acceleration are the best predictors of immediately diagnosed concussion.

Head Impact Exposure Sustained by Football Players on Days of Diagnosed Concussion

PubMed Central

Beckwith, Jonathan G.; Greenwald, Richard M.; Chu, Jeffrey J.; Crisco, Joseph J.; Rowson, Steven; Duma, Stefan M.; Broglio, Steven P.; McAllister, Thomas W.; Guskiewicz, Kevin M.; Mihalik, Jason P.; Anderson, Scott; Schnebel, Brock; Brolinson, P. Gunnar; Collins, Michael W.

2012-01-01

Purpose This study compares the frequency and severity of head impacts sustained by football players on days with and without diagnosed concussion and to identify the sensitivity and specificity of single impact severity measures to diagnosed injury. Methods 1,208 players from eight collegiate and six high school football teams wore instrumented helmets to measure head impacts during all team sessions, of which 95 players were diagnosed with concussion. Eight players sustained two injuries and one three, providing 105 injury cases. Measures of head kinematics (peak linear and rotational acceleration, Gadd Severity Index (GSI), Head Injury Criteria (HIC15), change in head velocity (Δv)) and the number of head impacts sustained by individual players were compared between days with and without diagnosed concussion. Receiver operator characteristic curves were generated to evaluate the sensitivity and specificity of each kinematic measure to diagnosed concussion using only those impacts that directly preceded diagnosis. Results Players sustained a higher frequency of impacts and impacts with more severe kinematic properties on days of diagnosed concussion than on days without diagnosed concussion. Forty-five injury cases were immediately diagnosed following head impact. For these cases, peak linear acceleration and HIC15 were most sensitive to immediately diagnosed concussion (AUC = 0.983). Peak rotational acceleration was less sensitive to diagnosed injury than all other kinematic measures (p = 0.01) which are derived from linear acceleration (peak linear, HIC15, GSI, and Δv). Conclusions Players sustain more impacts and impacts of higher severity on days of diagnosed concussion than on days without diagnosed concussion. Additionally, of historical measures of impact severity, those associated with peak linear acceleration are the best predictors of immediately diagnosed concussion. PMID:23135363

Masculinity, moral atmosphere, and moral functioning of high school football players.

PubMed

Steinfeldt, Jesse A; Rutkowski, Leslie A; Vaughan, Ellen L; Steinfeldt, Matthew C

2011-04-01

In order to identify factors associated with on-field moral functioning among student athletes within the unique context of football, we examined masculine gender role conflict, moral atmosphere, and athletic identity. Using structural equation modeling to assess survey data from 204 high school football players, results demonstrated that moral atmosphere (i.e., the influence of coaches and teammates) was significantly associated with participants' process of on-field moral functioning across the levels of judgment, intention, and behavior. Neither masculine gender role conflict nor athletic identity significantly predicted moral functioning, but the results indicated that participants' identification with the athlete role significantly predicted conflict with socialized gender roles. Results suggest that in the aggressive and violent sport of football, coaches can have a direct influence on players' moral functioning process. Coaches can also have an indirect effect by influencing all the players so that a culture of ethical play can be cultivated among teammates and spread from the top down.

Player Modeling for Intelligent Difficulty Adjustment

NASA Astrophysics Data System (ADS)

Missura, Olana; Gärtner, Thomas

In this paper we aim at automatically adjusting the difficulty of computer games by clustering players into different types and supervised prediction of the type from short traces of gameplay. An important ingredient of video games is to challenge players by providing them with tasks of appropriate and increasing difficulty. How this difficulty should be chosen and increase over time strongly depends on the ability, experience, perception and learning curve of each individual player. It is a subjective parameter that is very difficult to set. Wrong choices can easily lead to players stopping to play the game as they get bored (if underburdened) or frustrated (if overburdened). An ideal game should be able to adjust its difficulty dynamically governed by the player’s performance. Modern video games utilise a game-testing process to investigate among other factors the perceived difficulty for a multitude of players. In this paper, we investigate how machine learning techniques can be used for automatic difficulty adjustment. Our experiments confirm the potential of machine learning in this application.

Multivariate Profiles of Selected versus Non-Selected Elite Youth Brazilian Soccer Players

PubMed Central

Alves, Isabella S.; Padilha, Maickel B.; Casanova, Filipe; Puggina, Enrico F.; Maia, José

2017-01-01

Abstract This study determined whether a multivariate profile more effectively discriminated selected than non-selected elite youth Brazilian soccer players. This examination was carried out on 66 youth soccer players (selected, n = 28, mean age 16.3 ± 0.1; non-selected, n = 38, mean age 16.7 ± 0.4) using objective instruments. Multivariate profiles were assessed through anthropometric characteristics, biological maturation, tactical-technical skills, and motor performance. The Student’s t-test identified that selected players exhibited significantly higher values for height (t = 2.331, p = 0.02), lean body mass (t = 2.441, p = 0.01), and maturity offset (t = 4.559, p < 0.001), as well as performed better in declarative tactical knowledge (t = 10.484, p < 0.001), shooting (t = 2.188, p = 0.03), dribbling (t = 5.914, p < 0.001), speed – 30 m (t = 8.304, p < 0.001), countermovement jump (t = 2.718, p = 0.008), and peak power tests (t = 2.454, p = 0.01). Forward stepwise discriminant function analysis showed that declarative tactical knowledge, running speed –30 m, maturity offset, dribbling, height, and peak power correctly classified 97% of the selected players. These findings may have implications for a highly efficient selection process with objective measures of youth players in soccer clubs. PMID:29339991

Effect of Physical and Psychosocial Interventions on Hormone and Performance Outcomes in Professional Rugby Union Players: A Systematic Review.

PubMed

Strahorn, Joshua; Serpell, Benjamin G; McKune, Andrew; Pumpa, Kate L

2017-11-01

Strahorn, J, Serpell, BG, McKune, A, and Pumpa, KL. Effect of physical and psychosocial interventions on hormone and performance outcomes in professional rugby union players: a systematic review. J Strength Cond Res 31(11): 3158-3169, 2017-This systematic review investigates the acute effects of physical or psychosocial interventions on testosterone and cortisol responses in elite male rugby union players, and the subsequent association with physical performance areas (e.g., strength, power, sprint performance) or key performance indicators (e.g., coach-identified skills). Medline (via EBSCO), SPORTDiscus, Web of Science, InformIT, ProQuest, Cochrane, and Scopus were searched for relevant articles. Nine articles met the inclusion criteria, with 6 articles examining the effect of speed, strength or power training, and the remaining 3 psychosocial interventions. Quality assessment of the articles as determined by their PEDro score was either 6 or 7 out of 11. This review found that both physical and psychosocial interventions can alter testosterone and cortisol, and physical performance areas important for rugby union are affected by these changes. The limited literature in the field supports the notion that physical interventions of short duration and high intensity, and psychosocial interventions that create a positive environment may elicit a hormonal response that is associated with favorable performance outcomes. Studies that reported psychosocial interventions suggest that testosterone and cortisol may be altered in elite rugby players without metabolic stress, something of great interest to elite athletes and coaches who are looking to elicit a performance advantage without increasing athlete load. Overall, this review identified that when the testosterone responses to an intervention are notably greater than that of cortisol, favorable outcomes are likely. Further research is required to improve our understanding on how to best manipulate training to induce

Return to Play and Decreased Performance After Anterior Cruciate Ligament Reconstruction in National Football League Defensive Players.

PubMed

Read, Connor R; Aune, Kyle T; Cain, E Lyle; Fleisig, Glenn S

2017-07-01

Anterior cruciate ligament (ACL) injuries occur commonly in football. Recent work has reported ACL reconstruction (ACLR) as one of several orthopaedic procedures with unfavorable outcomes for professional athletes. The performance impact to defensive players after surgery has not been quantified. To quantify the effect of ACLR on the performance of defensive players by comparing them to a cohort of matched controls as well as to measure the effect of ACLR on athletes' career length in the National Football League (NFL). Case-control and cohort study; Level of evidence, 3. Thirty-eight NFL defensive players with a history of ACLR from 2006 to 2012 were identified. For each injured player, a matched control player was identified. Demographic and performance statistics were collected from the online NFL player database. Players who returned after ACLR (n = 23) were compared with players who did not return (n = 15) using t tests and chi-squared analyses. Similarly, players who returned after ACLR (n = 23) were compared with their matched controls with t tests and chi-squared analyses. Two-way repeated-measures analysis of variance was utilized to test for significant differences between performance before and after the season of the injury for the players in the ACLR group who returned (n = 23) and for their matched controls. Kaplan-Meier analysis was performed to test for differences in the rate of retirement between the groups. For all analyses, P values <.05 were considered significant. Approximately 74% (28/38) of athletes who underwent ACLR returned to play at least 1 NFL game, and 61% (23/38) successfully returned to play at least half a season (ie, 8 games). Athletes in the ACLR group who returned retired from the NFL significantly sooner and more often after surgery than their matched controls. In the seasons leading up to their injury, athletes who successfully returned to play started a greater percentage of their games (81%) and made more solo tackles per

Comparing Performance During Morning vs. Afternoon Training Sessions in Intercollegiate Basketball Players.

PubMed

Heishman, Aaron D; Curtis, Michael A; Saliba, Ethan N; Hornett, Robert J; Malin, Steven K; Weltman, Arthur L

2017-06-01

Time of day is a key factor that influences the optimization of athletic performance. Intercollegiate coaches oftentimes hold early morning strength training sessions for a variety of factors including convenience. However, few studies have specifically investigated the effect of early morning vs. late afternoon strength training on performance indices of fatigue. This is athletically important because circadian and/or ultradian rhythms and alterations in sleep patterns can affect training ability. Therefore, the purpose of the present study was to examine the effects of morning vs. afternoon strength training on an acute performance index of fatigue (countermovement jump height, CMJ), player readiness (Omegawave), and self-reported sleep quantity. We hypothesized that afternoon training sessions would be associated with increased levels of performance, readiness, and self-reported sleep. A retrospective analysis was performed on data collected over the course of the preseason on 10 elite National Collegiate Athletic Association Division 1 male basketball players. All basketball-related activities were performed in the afternoon with strength and conditioning activities performed either in the morning or in the afternoon. The average values for CMJ, power output (Power), self-reported sleep quantity (sleep), and player readiness were examined. When player load and duration were matched, CMJ (58.8 ± 1.3 vs. 61.9 ± 1.6 cm, p = 0.009), Power (6,378.0 ± 131.2 vs. 6,622.1 ± 172.0 W, p = 0.009), and self-reported sleep duration (6.6 ± 0.4 vs. 7.4 ± 0.25 p = 0.016) were significantly higher with afternoon strength and conditioning training, with no differences observed in player readiness values. We conclude that performance is suppressed with morning training and is associated with a decrease in self-reported quantity of sleep.

Hamstrings strength imbalance in professional football (soccer) players in Australia.

PubMed

Ardern, Clare L; Pizzari, Tania; Wollin, Martin R; Webster, Kate E

2015-04-01

The aim of this study was to describe the isokinetic thigh muscle strength profile of professional male football players in Australia. Concentric (60° and 240°·s(-1)) and eccentric (30° and 120°·s(-1)) hamstrings and quadriceps isokinetic strength was measured with a HUMAC NORM dynamometer. The primary variables were bilateral concentric and eccentric hamstring and quadriceps peak torque ratios, concentric hamstring-quadriceps peak torque ratios, and mixed ratios (eccentric hamstring 30°·s(-1) ÷ concentric quadriceps 240°·s(-1)). Hamstring strength imbalance was defined as deficits in any 2 of: bilateral concentric hamstring peak torque ratio <0.86, bilateral eccentric hamstring peak torque ratio <0.86, concentric hamstring-quadriceps ratio <0.47, and mixed ratio <0.80. Fifty-five strength tests involving 42 players were conducted. Ten players (24%) were identified as having hamstring strength imbalance. Athletes with strength imbalance had significantly reduced concentric and eccentric bilateral hamstring peak torque ratios at all angular velocities tested; and reduced eccentric quadriceps peak torque (30°·s(-1)) in their stance leg, compared with those without strength imbalance. Approximately, 1 in 4 players had preseason hamstring strength imbalance; and all strength deficits were observed in the stance leg. Concentric and eccentric hamstrings strength imbalance may impact in-season football performance and could have implications for the future risk of injury.

Rotational glenohumeral adaptations are associated with shoulder pathology in professional male handball players.

PubMed

Lubiatowski, Przemyslaw; Kaczmarek, Piotr; Cisowski, Pawel; Breborowicz, Ewa; Grygorowicz, Monika; Dzianach, Marcin; Krupecki, Tomasz; Laver, Lior; Romanowski, Leszek

2018-01-01

Glenohumeral range of motion adaptations may affect throwing athletes and contribute to shoulder injury. The purpose of this study was to evaluate shoulder rotation deficits among elite professional handball players and its correlation to the presence of shoulder pain and morphological changes. Eighty-seven elite professional handball players and 41 healthy non-athlete volunteers participated in the study. Evaluations included measurement of range of internal and external rotation, total arch of motion, identification of shoulder pain and ultrasound scan for diagnosis of rotator cuff tears and internal impingement. Glenohumeral rotational deficits (>20-25°) were found among 11 players group (13%). The throwing shoulders in the players group showed a decrease in internal rotation and an increase in external rotation with significantly larger ranges among players compared to the non-athlete group. Internal rotation deficit >20° was associated with higher incidence of shoulder pain among players. Both internal rotation deficits (>25°) and total arch of motion deficit (>20°) co-existed with higher incidence of internal impingement. Shoulder pain was common (36/97-41%) and was associated with decreased external rotation and total arch of motion. Internal impingement (found in 13/87-15%) correlated with decreased rotation ranges and a greater deficit in total arch of motion, whereas higher gain in external rotation correlated with a partial rotator cuff tear (found in 12/87-14%). Shoulder pathologies and problems commonly affected the group of handball players. Greater glenohumeral rotational deficits in throwing shoulders of handball players correlate with shoulder pain and internal impingement, while increased external rotation with partial rotator cuff tears. Such deficits affect 13% of the athlete population. Major clinical relevance of the study is to monitor handball players' shoulders both clinically and by proper imaging. Evaluation of range of rotation seems

Higher Drop in Speed during a Repeated Sprint Test in Soccer Players Reporting Former Hamstring Strain Injury

PubMed Central

Røksund, Ola D.; Kristoffersen, Morten; Bogen, Bård E.; Wisnes, Alexander; Engeseth, Merete S.; Nilsen, Ann-Kristin; Iversen, Vegard V.; Mæland, Silje; Gundersen, Hilde

2017-01-01

Aim: Hamstring strain injury is common in soccer. The aim of this study was to evaluate the physical capacity of players who have and have not suffered from hamstring strain injury in a sample of semi-professional and professional Norwegian soccer players in order to evaluate characteristics and to identify possible indications of insufficient rehabilitation. Method: Seventy-five semi-professional and professional soccer players (19 ± 3 years) playing at the second and third level in the Norwegian league participated in the study. All players answered a questionnaire, including one question about hamstring strain injury (yes/no) during the previous 2 years. They also performed a 40 m maximal sprint test, a repeated sprint test (8 × 20 m), a countermovement jump, a maximal oxygen consumption (VO2max) test, strength tests and flexibility tests. Independent sample t-tests were used to evaluate differences in the physical capacity of the players who had suffered from hamstring strain injury and those who had not. Mixed between-within subject's analyses of variance was used to compare changes in speed during the repeated sprint test between groups. Results: Players who reported hamstring strain injury during the previous two years (16%) had a significantly higher drop in speed (0.07 vs. 0.02 s, p = 0.007) during the repeated sprint test, compared to players reporting no previous hamstring strain injury. In addition, there was a significant interaction (groups × time) (F = 3.22, p = 0.002), showing that speed in the two groups changed differently during the repeated sprint test. There were no significant differences in relations to age, weight, height, body fat, linear speed, countermovement jump height, leg strength, VO2max, or hamstring flexibility between the groups. Conclusion: Soccer players who reported hamstring strain injury during the previous 2 years showed significant higher drop in speed during the repeated sprint test compared to players with no hamstring

Dominant-Limb Range-of-Motion and Humeral-Retrotorsion Adaptation in Collegiate Baseball and Softball Position Players

PubMed Central

Hibberd, Elizabeth E.; Oyama, Sakiko; Tatman, Justin; Myers, Joseph B.

2014-01-01

Context: Biomechanically, the motions used by baseball and softball pitchers differ greatly; however, the throwing motions of position players in both sports are strikingly similar. Although the adaptations to the dominant limb from overhead throwing have been well documented in baseball athletes, these adaptations have not been clearly identified in softball players. This information is important in order to develop and implement injury-prevention programs specific to decreasing the risk of upper extremity injury in softball athletes. Objective: To compare range-of-motion and humeral-retrotorsion characteristics of collegiate baseball and softball position players and of baseball and softball players to sex-matched controls. Design: Cross-sectional study. Setting: Research laboratories and athletic training rooms at the University of North Carolina at Chapel Hill. Patients or Other Participants: Fifty-three collegiate baseball players, 35 collegiate softball players, 25 male controls (nonoverhead athletes), and 19 female controls (nonoverhead athletes). Intervention(s): Range of motion and humeral retrotorsion were measured using a digital inclinometer and diagnostic ultrasound. Main Outcome Measure(s): Glenohumeral internal-rotation deficit, external-rotation gain, total glenohumeral range of motion, and humeral retrotorsion. Results: Baseball players had greater glenohumeral internal-rotation deficit, total–range-of-motion, and humeral-retrotorsion difference than softball players and male controls. There were no differences between glenohumeral internal-rotation deficit, total–range-of-motion, and humeral-retrotorsion difference in softball players and female controls. Conclusions: Few differences were evident between softball players and female control participants, although range-of-motion and humeral-retrotorsion adaptations were significantly different than baseball players. The throwing motions are similar between softball and baseball, but the

Characteristics of upper limb muscular strength in male wheelchair tennis players

PubMed Central

Moon, Hyo-Bin; Park, Seung-Jae; Kim, Al-Chan; Jang, Jee-Hun

2013-01-01

The purpose of this study was to identify the characteristics of muscular strength in upper limb and to present the preliminary information for development of sports injury prevention program and exercise rehabilitation program in wheelchair tennis players. Participants were 12 male wheelchair tennis players. Muscular strength was measured in shoulder and elbow joints with isokinetic dynamometer. Ipsilateral (IR) and bilateral (BR) balance ratio were calculated with isokinetic strength at 60°/sec. As a result, extension strength (ES) was significantly higher than flexion strength (FS) (P< 0.001), and IR in both sides and BR in ES were maintained within normal range whereas BR in FS was lower than normal range in shoulder joint. In elbow joint FS was significantly higher than ES (P< 0.05), and IR and BR were lower than normal range. Consequently, the different tendency in IR between shoulder and elbow joints and lower IR and BR in elbow joints could be the characteristics in male wheelchair tennis players. It is suggested that flexor strengthening program in nondominant shoulder joint, extensor strengthening program in both elbow joint, and flexor strengthening program in non-dominant elbow joint should be introduced for male wheelchair tennis players. PMID:24278887

Sulfur Denitrosylation by an Engineered Trx-like DsbG Enzyme Identifies Nucleophilic Cysteine Hydrogen Bonds as Key Functional Determinant.

PubMed

Lafaye, Céline; Van Molle, Inge; Tamu Dufe, Veronica; Wahni, Khadija; Boudier, Ariane; Leroy, Pierre; Collet, Jean-François; Messens, Joris

2016-07-15

Exposure of bacteria to NO results in the nitrosylation of cysteine thiols in proteins and low molecular weight thiols such as GSH. The cells possess enzymatic systems that catalyze the denitrosylation of these modified sulfurs. An important player in these systems is thioredoxin (Trx), a ubiquitous, cytoplasmic oxidoreductase that can denitrosylate proteins in vivo and S-nitrosoglutathione (GSNO) in vitro However, a periplasmic or extracellular denitrosylase has not been identified, raising the question of how extracytoplasmic proteins are repaired after nitrosative damage. In this study, we tested whether DsbG and DsbC, two Trx family proteins that function in reducing pathways in the Escherichia coli periplasm, also possess denitrosylating activity. Both DsbG and DsbC are poorly reactive toward GSNO. Moreover, DsbG is unable to denitrosylate its specific substrate protein, YbiS. Remarkably, by borrowing the CGPC active site of E. coli Trx-1 in combination with a T200M point mutation, we transformed DsbG into an enzyme highly reactive toward GSNO and YbiS. The pKa of the nucleophilic cysteine, as well as the redox and thermodynamic properties of the engineered DsbG are dramatically changed and become similar to those of E. coli Trx-1. X-ray structural insights suggest that this results from a loss of two direct hydrogen bonds to the nucleophilic cysteine sulfur in the DsbG mutant. Our results highlight the plasticity of the Trx structural fold and reveal that the subtle change of the number of hydrogen bonds in the active site of Trx-like proteins is the key factor that thermodynamically controls reactivity toward nitrosylated compounds. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Event-related potential effects of superior action anticipation in professional badminton players.

PubMed

Jin, Hua; Xu, Guiping; Zhang, John X; Gao, Hongwei; Ye, Zuoer; Wang, Pin; Lin, Huiyan; Mo, Lei; Lin, Chong-De

2011-04-04

The ability to predict the trajectory of a ball based on the opponent's body kinematics has been shown to be critical to high-performing athletes in many sports. However, little is known about the neural correlates underlying such superior ability in action anticipation. The present event-related potential study compared brain responses from professional badminton players and non-player controls when they watched video clips of badminton games and predicted a ball's landing position. Replicating literature findings, the players made significantly more accurate judgments than the controls and showed better action anticipation. Correspondingly, they showed enlarged amplitudes of two ERP components, a P300 peaking around 350ms post-stimulus with a parietal scalp distribution and a P2 peaking around 250ms with a posterior-occipital distribution. The P300 effect was interpreted to reflect primed access and/or directing of attention to game-related memory representations in the players facilitating their online judgment of related actions. The P2 effect was suggested to reflect some generic learning effects. The results identify clear neural responses that differentiate between different levels of action anticipation associated with sports expertise. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Risk factors that predict severe injuries in university rugby sevens players.

PubMed

Mirsafaei Rizi, Rezvan; Yeung, Simon S; Stewart, Nathan J; Yeung, Ella W

2017-07-01

To investigate injury incidence and the influence of physical fitness parameters on the risk of severe injuries in players on rugby sevens university teams. Prospective cohort study. Rugby players from three universities (N=104; 90M:14F; 20.6±1.9years) were recruited before the beginning of the season. Players underwent pre-season assessments of power, strength, speed, agility, endurance, stability, and flexibility. Throughout the season, rugby-related injury and exposure data were collected. Potential predictor variables were analyzed using Cox proportional regression model to identify risk factors associated with severe injuries (time loss>28days). Thirty-one injuries occurred during the rugby season. The match and training injury incidence rates were 59.3 injuries and 3.3 injuries per 1000 player-hours, respectively. Lower limb injuries were most common and most severe. The ankle joint was the most prevalent site of injury, and ligamentous injury was most common (48.4%). Nine severe injuries were sustained resulting in an average time loss of 51.3±14.6days. Female (hazard ratio [HR]=8.35; 95% confidence intervals [CI]=2.01-34.8), slower (HR=3.51; 95% CI=1.17-10.5), and less agile (HR=2.22; 95% CI=1.26-3.92) players as well as those with hip flexors tightness (HR=1.12; 95% CI=1.00-1.25) were at significantly greater risk for sustaining severe injuries. Limited studies are available on risk factors associated with amateur rugby players in the Sevens version. The development of gender-specific injury prevention measures that emphasize speed and agility training, and improve hip flexor extensibility may be important to reduce the risk of severe injuries. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Reliability and Usefulness of Linear Sprint Testing in Adolescent Rugby Union and League Players.

PubMed

Darrall-Jones, Joshua D; Jones, Ben; Roe, Gregory; Till, Kevin

2016-05-01

The purpose of this study was to evaluate (a) whether there were differences in sprint times at 5, 10, 20, 30, and 40 m between rugby union and rugby league players, (b) determine the reliability and usefulness of linear sprint testing in adolescent rugby players. Data were collected on 28 rugby union and league academy players over 2 testing sessions, with 3-day rest between sessions. Rugby league players were faster at 5 m than rugby union players, with further difference unclear. Sprint time at 10, 20, 30, and 40 m was all reliable (coefficient of variation [CV] = 3.1, 1.8, 2.0, and 1.3%) but greater than the smallest worthwhile change (SWC [0.2 × between-subject SD]), rating the test as marginal for usefulness. Although the test was incapable of detecting the SWC, we recommend that practitioners and researchers use Hopkins' proposed method; whereby plotting the change score of the individual at each split (±typical error [TE] expressed as a CV) against the SWC and visually inspecting whether the TE crosses into the SWC are capable of identifying whether a change is both real (greater than the noise of the test, i.e., >TE) and of practical significance (>SWC). Researchers and practitioners can use the TE and SWC from this study to assess changes in performance of adolescent rugby players when using single beam timing gates.

A data mining paradigm for identifying key factors in biological processes using gene expression data.

PubMed

Li, Jin; Zheng, Le; Uchiyama, Akihiko; Bin, Lianghua; Mauro, Theodora M; Elias, Peter M; Pawelczyk, Tadeusz; Sakowicz-Burkiewicz, Monika; Trzeciak, Magdalena; Leung, Donald Y M; Morasso, Maria I; Yu, Peng

2018-06-13

A large volume of biological data is being generated for studying mechanisms of various biological processes. These precious data enable large-scale computational analyses to gain biological insights. However, it remains a challenge to mine the data efficiently for knowledge discovery. The heterogeneity of these data makes it difficult to consistently integrate them, slowing down the process of biological discovery. We introduce a data processing paradigm to identify key factors in biological processes via systematic collection of gene expression datasets, primary analysis of data, and evaluation of consistent signals. To demonstrate its effectiveness, our paradigm was applied to epidermal development and identified many genes that play a potential role in this process. Besides the known epidermal development genes, a substantial proportion of the identified genes are still not supported by gain- or loss-of-function studies, yielding many novel genes for future studies. Among them, we selected a top gene for loss-of-function experimental validation and confirmed its function in epidermal differentiation, proving the ability of this paradigm to identify new factors in biological processes. In addition, this paradigm revealed many key genes in cold-induced thermogenesis using data from cold-challenged tissues, demonstrating its generalizability. This paradigm can lead to fruitful results for studying molecular mechanisms in an era of explosive accumulation of publicly available biological data.

N-player stochastic differential games

NASA Technical Reports Server (NTRS)

Varaiya, P.

1976-01-01

The paper presents conditions which guarantee that the control strategies adopted by N players constitute an efficient solution, an equilibrium, or a core solution. The system dynamics are described by an Ito equation, and all players have perfect information. When the set of instantaneous joint costs and velocity vectors is convex, the conditions are necessary.

Arthroscopic Shoulder Surgery in Female Professional Tennis Players: Ability and Timing to Return to Play.

PubMed

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

2017-07-01

To assess the outcome and time to return to previous level of competitive play after shoulder surgery in professional tennis players. Retrospective case series. Tertiary academic centre. 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. Primary outcomes were the 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. Preoperative and postoperative singles rankings were used to determine rate and completeness of return to preoperative function. During the study period, 8 professional women tennis players from the WTA tour underwent shoulder surgery on their dominant arm. Indications included rotator cuff debridement or repair, labral reconstruction for instability or superior labral anterior posterior lesion, and neurolysis of the suprascapular nerve. Seven players (88%) returned to professional play. The mean time to return to play was 7 months after surgery. However, only 25% (2 of 8) players achieved their preinjury singles rank or better by 18 months postoperatively. In total, 4 players returned to their preinjury singles ranking, with their peak singles ranking being attained at a mean of 2.4 years postoperatively. In professional female tennis players, a high return to play rate after arthroscopic shoulder surgery is associated with a prolonged and often incomplete return to previous level of performance. Thus, counseling the patient to this fact is important to manage expectations. Level IV-Case Series.

Identifying and characterizing key nodes among communities based on electrical-circuit networks.

PubMed

Zhu, Fenghui; Wang, Wenxu; Di, Zengru; Fan, Ying

2014-01-01

Complex networks with community structures are ubiquitous in the real world. Despite many approaches developed for detecting communities, we continue to lack tools for identifying overlapping and bridging nodes that play crucial roles in the interactions and communications among communities in complex networks. Here we develop an algorithm based on the local flow conservation to effectively and efficiently identify and distinguish the two types of nodes. Our method is applicable in both undirected and directed networks without a priori knowledge of the community structure. Our method bypasses the extremely challenging problem of partitioning communities in the presence of overlapping nodes that may belong to multiple communities. Due to the fact that overlapping and bridging nodes are of paramount importance in maintaining the function of many social and biological networks, our tools open new avenues towards understanding and controlling real complex networks with communities accompanied with the key nodes.

Anthropometric and physical performance characteristics of top-elite, elite and non-elite youth female team handball players.

PubMed

Moss, Samantha Louise; McWhannell, Nicola; Michalsik, Lars Bojsen; Twist, Craig

2015-01-01

In order to maximise the potential for success, developing nations need to produce superior systems to identify and develop talent, which requires comprehensive and up-to-date values on elite players. This study examined the anthropometric and physical characteristics of youth female team handball players (16.07 ± 1.30 years) in non-elite (n = 47), elite (n = 37) and top-elite players (n = 29). Anthropometric profiling included sum of eight skinfolds, body mass, stature, girths, breadths and somatotype. Performance tests included 20 m sprint, counter-movement jump, throwing velocity, repeated shuttle sprint and jump ability test, and Yo-Yo Intermittent Recovery Test Level 1. Youth top-elite players had greater body mass, lean mass, stature, limb girths and breadths than elite and non-elite players, while only stature and flexed arm were higher in elite compared to non-elite players (all P < 0.05). Sum of skinfolds and waist-to-hip ratio were similar between groups (P > 0.05). Top-elite performed better in most performance tests compared to both elite and non-elite players (P < 0.05), although maximal and repeated 10 m sprints were similar between playing standards (P > 0.05). Elite outperformed non-elite players only in throwing velocity. The findings reveal that non-elite players compare unfavourably to top-elite international European players in many anthropometric and performance characteristics, and differ in a few characteristics compared to elite European club team players. This study is useful for emerging team handball nations in improving talent identification processes.

Does player time-in-game affect tackle technique in elite level rugby union?

PubMed

Tierney, Gregory J; Denvir, Karl; Farrell, Garreth; Simms, Ciaran K

2018-02-01

It has been hypothesised that fatigue may be a major factor in tackle-related injury risk in rugby union and hence more injuries occur in the later stages of a game. The aim of this study is to identify changes in ball carrier or tackler proficiency characteristics, using elite level match video data, as player time-in-game increases. Qualitative observational cohort study. Three 2014/15 European Rugby Champions Cup games were selected for ball carrier and tackler proficiency analysis. Analysis was only conducted on players who started and remained on the field for the entire game. A separate analysis was conducted on 10 randomly selected 2014/15 European Rugby Champions Cup/Pro 12 games to assess the time distribution of tackles throughout a game. A Chi-square test and one-way way ANOVA with post-hoc testing was conducted to identify significant differences (p<0.05) for proficiency characteristics and tackle counts between quarters in the game, respectively. Player time-in-game did not affect tackle proficiency for both the ball carrier and tackler. Any results that showed statistical significance did not indicate a trend of deterioration in proficiency with increased player time-in-game. The time distribution of tackles analysis indicated that more tackles occurring in the final quarter of the game than the first (p=0.04) and second (p=<0.01). It appears that player time-in-game does not affect tackler or ball carrier tackle technique proficiency at the elite level. More tackles occurring in the final quarter of a game provides an alternative explanation to more tackle-related injuries occurring at this stage. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

What do adult squash players think about protective eyewear?

PubMed Central

Finch, C.; Vear, P.

1998-01-01

OBJECTIVE: To determine the attitudes of adult squash players towards protective eyewear. METHODS: A survey of 197 competition and social squash players from seven squash centres in the outer eastern suburbs of Melbourne, Australia was conducted in September to October 1995. Information about participation in squash, previous injuries, use of protective eyewear, barriers towards eyewear use, and attitudes towards protective eyewear was obtained by a self report questionnaire. RESULTS: Squash is a popular sport in Australia. Of the players surveyed, 6% played in junior competitions, 67% in senior competitions, and 27% were social players. Most had been playing for more than ten years. Some 15% of players had previously suffered an eye injury, most commonly caused by a racquet. Less than 10% of players reported that they wore protective eyewear when they played squash, and 35% of these wore prescriptive lenses which they considered to be protective. The major reason for not wearing protective eyewear was the perception that it was unnecessary. Poor vision and a lack of comfort were also stated as reasons by a significant number of players. More than half (57%) of the respondents agreed that more players should wear protective eyewear, yet only 16% thought it should be compulsory for all players. There was considerable support for protective eyewear use by junior players, however. CONCLUSIONS: The rate of protective eyewear use is low among competition and social squash players in Melbourne. The major areas that need to be addressed are the ignorance of the need for protective eyewear among social and experienced players and the mistaken belief that prescription lenses provide adequate protection on a squash court. 


 PMID:9631225

Reactive Oxygen Species and NOX Enzymes Are Emerging as Key Players in Cutaneous Wound Repair

PubMed Central

Modarressi, Ali; Pittet-Cuénod, Brigitte

2017-01-01

Our understanding of the role of oxygen in cell physiology has evolved from its long-recognized importance as an essential factor in oxidative metabolism to its recognition as an important player in cell signaling. With regard to the latter, oxygen is needed for the generation of reactive oxygen species (ROS), which regulate a number of different cellular functions including differentiation, proliferation, apoptosis, migration, and contraction. Data specifically concerning the role of ROS-dependent signaling in cutaneous wound repair are very limited, especially regarding wound contraction. In this review we provide an overview of the current literature on the role of molecular and reactive oxygen in the physiology of wound repair as well as in the pathophysiology and therapy of chronic wounds, especially under ischemic and hyperglycemic conditions. PMID:29036938

Fitness profiling in handball: physical and physiological characteristics of elite players.

PubMed

Sporis, Goran; Vuleta, Dinko; Vuleta, Dinko; Milanović, Dragan

2010-09-01

The purpose of this study was to describe the structural and functional characteristics of elite Croatian handball players and to evaluate whether the players in different positional roles have different physical and physiological profiles. According to the positional roles, players were categorized as goalkeepers (n = 13), wing players (n = 26), backcourt players (n = 28) and pivot players (n = 25). The goalkeepers were older (p < 0.01), and the pivot players were more experienced (p < 0.01) than the backcourt players. The wings were the shortest players in the team. The pivots were tallest and heavier than the backcourt and wing players (p < 0.01), whereas the backcourt players were tallest then wings (p < 0.01). Goalkeepers had more body fat than the backcourt and wing players (p < 0.01). The backcourt players had a lower percentage of body fat. The backcourt players were the quickest players in the team when looking at values of maximal running speed on a treadmill. The Goalkeepers were the slowest players in the team (p < 0.01). The best average results concerning maximal heart rate were detected among the backcourt players. There were no statistically significant differences between the players'positions when measuring blood lactate and maximal heart rate. A strong negative correlation was found between body fat and maximal running speed (r = -0.68, p < 0.01). Coaches are able to use this information to determine which type of profile is needed for a specific position. Experienced coaches can used this information in the process of designing a training program to maximize the fitness development of handball players, with one purpose only, to achieve success in handball.

Bridging Media with the Help of Players

NASA Astrophysics Data System (ADS)

Nitsche, Michael; Drake, Matthew; Murray, Janet

We suggest harvesting the power of multiplayer design to bridge content across different media platforms and develop player-driven cross-media experiences. This paper first argues to partially replace complex AI systems with multiplayer design strategies to provide the necessary level of flexibility in the content generation for cross-media applications. The second part describes one example project - the Next Generation Play (NGP) project - that illustrates one practical approach of such a player-driven cross-media content generation. NGP allows players to collect virtual items while watching a TV show. These items are re-used in a multiplayer casual game that automatically generates new game worlds based on the various collections of active players joining a game session. While the TV experience is designed for the single big screen, the game executes on multiple mobile phones. Design and technical implementation of the prototype are explained in more detail to clarify how players carry elements of television narratives into a non-linear handheld gaming experience. The system describes a practical way to create casual game adaptations based on players' personal preferences in a multi-user environment.

Vitamin D profile in National Football League players.

PubMed

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

A Review of the Anthropometric Characteristics, Grading and Dispensation of Junior and Youth Rugby Union Players in Australia.

PubMed

Patton, Declan Alexander; McIntosh, Andrew Stuart; Denny, Greg

2016-08-01

The grading of Australian junior and youth rugby union players has received substantial media attention in recent years. Media reports have focussed on size mismatches observed between players, especially players with Polynesian heritage, and the concerned parents who fear for the safety of their child owing to perceived mismatches. Although such concerns are well meaning, few media reports recognise the need for substantial evidence to determine the best grading system for junior and youth rugby union players. The current study reviewed relevant literature pertinent to the grading and dispensation of junior and youth rugby union players. Using primary and secondary search strategies, a total of 33 articles reporting the anthropometric characteristics of junior and youth rugby players were identified. Anthropometric data from the literature were compared with normative population data and currently used dispensation criteria. Junior and youth rugby players were found to be taller and heavier than normative population data. Current dispensation criteria, in terms of body mass, were found to vary and it is suggested that criteria be revised and standardised across rugby unions throughout Australia. Although it is acknowledged that other factors are important for grading players, anthropometric characteristics should be considered as potential dispensation criteria to supplement current age-based grading for junior and youth rugby union players. Measuring the body mass and stature of each junior player upon pre-season registration is suggested, which would provide data to establish valid dispensation criteria for the following season.

Match analysis and player characteristics in rugby sevens.

PubMed

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

Parallax Player: a stereoscopic format converter

NASA Astrophysics Data System (ADS)

Feldman, Mark H.; Lipton, Lenny

2003-05-01

The Parallax Player is a software application that is, in essence, a stereoscopic format converter. Various formats may be inputted and outputted. In addition to being able to take any one of a wide variety of different formats and play them back on many different kinds of PCs and display screens. The Parallax Player has built into it the capability to produce ersatz stereo from a planar still or movie image. The player handles two basic forms of digital content - still images, and movies. It is assumed that all data is digital, either created by means of a photographic film process and later digitized, or directly captured or authored in a digital form. In its current implementation, running on a number of Windows Operating Systems, The Parallax Player reads in a broad selection of contemporary file formats.

Framework for Identifying Key Environmental Concerns in Marine Renewable Energy Projects- Appendices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kramer, Sharon; Previsic, Mirko; Nelson, Peter

2010-06-17

Marine wave and tidal energy technology could interact with marine resources in ways that are not well understood. As wave and tidal energy conversion projects are planned, tested, and deployed, a wide range of stakeholders will be engaged; these include developers, state and federal regulatory agencies, environmental groups, tribal governments, recreational and commercial fishermen, and local communities. Identifying stakeholders’ environmental concerns in the early stages of the industry’s development will help developers address and minimize potential environmental effects. Identifying important concerns will also assist with streamlining siting and associated permitting processes, which are considered key hurdles by the industry inmore » the U.S. today. In September 2008, RE Vision consulting, LLC was selected by the Department of Energy (DoE) to conduct a scenario-based evaluation of emerging hydrokinetic technologies. The purpose of this evaluation is to identify and characterize environmental impacts that are likely to occur, demonstrate a process for analyzing these impacts, identify the “key” environmental concerns for each scenario, identify areas of uncertainty, and describe studies that could address that uncertainty. This process is intended to provide an objective and transparent tool to assist in decision-making for siting and selection of technology for wave and tidal energy development. RE Vision worked with H. T. Harvey & Associates, to develop a framework for identifying key environmental concerns with marine renewable technology. This report describes the results of this study. This framework was applied to varying wave and tidal power conversion technologies, scales, and locations. The following wave and tidal energy scenarios were considered: 4 wave energy generation technologies 3 tidal energy generation technologies 3 sites: Humboldt coast, California (wave); Makapu’u Point, Oahu, Hawaii (wave); and the Tacoma Narrows, Washington

Ultrasonographic evaluation of the shoulder in elite Italian beach volleyball players.

PubMed

Monteleone, G; Tramontana, A; Mc Donald, K; Sorge, R; Tiloca, A; Foti, C

2015-10-01

Beach volleyball is an overhead sport that subjects the hitting shoulder to intense functional loads. The purpose of this study is to identify ultrasonographically the prevalence of myotendinous alterations in professional Italian beach volleyball players at the Italian championship and to look for associations between ultrasound findings and the other data collected. Fifty-three beach volleyball players (31 women, 22 men) were recruited during the second stage of the Italian championship held in July 2012 in Rome, Italy. Clinical history was obtained from all subjects, followed by physical exam. Each athlete completed a questionnaire regarding sports activities. Bilateral ultrasonographic evaluation of the shoulders was then performed. Calcific tendinopathy of the rotator cuff of the hitting shoulder was identified ultrasonographically in 30% of the athletes. The mean age of the athletes with calcific tendinopathy was older than subjects with other abnormalities on ultrasonographic examination (33.1 years vs. 25.8 years, t-test; P<0.0001). Impingement was recognized ultrasonographically in the hitting shoulder in 10 of the athletes (18.8%). The Neer's test was positive in the cases of anterior impingement (χ2; P<0.002). Calcific tendinopathy of the rotator cuff of the hitting shoulder in professional beach volleyball players has a prevalence of 30% ultrasonographically, greater than that reported in the general population. In these athletes, the presence of calcific tendinopathy correlates positively with age.

Modelling Creativity: Identifying Key Components through a Corpus-Based Approach

PubMed Central

2016-01-01

Creativity is a complex, multi-faceted concept encompassing a variety of related aspects, abilities, properties and behaviours. If we wish to study creativity scientifically, then a tractable and well-articulated model of creativity is required. Such a model would be of great value to researchers investigating the nature of creativity and in particular, those concerned with the evaluation of creative practice. This paper describes a unique approach to developing a suitable model of how creative behaviour emerges that is based on the words people use to describe the concept. Using techniques from the field of statistical natural language processing, we identify a collection of fourteen key components of creativity through an analysis of a corpus of academic papers on the topic. Words are identified which appear significantly often in connection with discussions of the concept. Using a measure of lexical similarity to help cluster these words, a number of distinct themes emerge, which collectively contribute to a comprehensive and multi-perspective model of creativity. The components provide an ontology of creativity: a set of building blocks which can be used to model creative practice in a variety of domains. The components have been employed in two case studies to evaluate the creativity of computational systems and have proven useful in articulating achievements of this work and directions for further research. PMID:27706185

Modelling Creativity: Identifying Key Components through a Corpus-Based Approach.

PubMed

Jordanous, Anna; Keller, Bill

2016-01-01

Creativity is a complex, multi-faceted concept encompassing a variety of related aspects, abilities, properties and behaviours. If we wish to study creativity scientifically, then a tractable and well-articulated model of creativity is required. Such a model would be of great value to researchers investigating the nature of creativity and in particular, those concerned with the evaluation of creative practice. This paper describes a unique approach to developing a suitable model of how creative behaviour emerges that is based on the words people use to describe the concept. Using techniques from the field of statistical natural language processing, we identify a collection of fourteen key components of creativity through an analysis of a corpus of academic papers on the topic. Words are identified which appear significantly often in connection with discussions of the concept. Using a measure of lexical similarity to help cluster these words, a number of distinct themes emerge, which collectively contribute to a comprehensive and multi-perspective model of creativity. The components provide an ontology of creativity: a set of building blocks which can be used to model creative practice in a variety of domains. The components have been employed in two case studies to evaluate the creativity of computational systems and have proven useful in articulating achievements of this work and directions for further research.

Longitudinal Study of Repeated Sprint Performance in Youth Soccer Players of Contrasting Skeletal Maturity Status

PubMed Central

Valente-dos-Santos, João; Coelho-e-Silva, Manuel J.; Severino, Vítor; Duarte, João; Martins, Raúl S.; Figueiredo, António J.; Seabra, André T.; Philippaerts, Renaat M.; Cumming, Sean P; Elferink-Gemser, Marije; Malina, Robert M.

2012-01-01

The purpose of the study was to evaluate the developmental changes in performance in a repeated-sprint ability (RSA) test in young soccer players of contrasting maturity status. A total of 83 regional level Portuguese youth soccer players, aged 11-13 years at baseline was assessed annually. Stature, body mass, 7x34.2-m sprint protocol (25-s active recovery), 20-m multi-stage continuous shuttle endurance run and counter-movement jump (CMJ) without the use of the arms were measured. Fat-free mass (FFM) was determined by age and gender-specific formulas. Developmental changes in total sprint time across ages were predicted using multilevel modeling. Corresponding measurements were performed on an independent cross-sectional subsample of 52 youth soccer players 11-17 years to evaluate the predictive model. CA, CA2, maturational status (SA-CA), body size (mass and stature), FFM, aerobic endurance, lower limb explosive strength and annual volume training significantly improved the statistical fit of the RSA multilevel model. In ‘late’ maturing athletes, the best model for predicting change in RSA was expressed by the following equation: 86.54 - 2.87 x CA + 0.05 x CA2 - 0.25 x FFM + 0.15 x body mass + 0.05 x stature - 0.05 x aerobic endurance - 0.09 x lower limb explosive strength - 0.01 x annual volume training. The best fitting models for players who were ‘on time’ and ‘early’ maturing were identical to the best model for late maturing players, less 0.64 seconds and 1.74 seconds, respectively. Multilevel modeling provided performance curves that permitted the prediction of individual RSA performance across adolescent years in regional level soccer players. Key pointsRepeated-sprint ability tests are a valuable sport-specific field test of sprint performance in youth soccer players. Here, the test had reasonable reliability and can be useful to trainers and coaches in the assessment of young athletes and in monitoring changes over time.The total sprint time

Outcomes of microfracture in professional basketball players.

PubMed

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 < 0.01) and 4.9 min (P < 0.05), respectively. The 17 players who continued to play two or more seasons after surgery, the average reduction in their PER and minutes per game was 2.7 (P > 0.05) and 3.0 min (P < 0.26), respectively. A multivariant comparison versus controls demonstrated that power rating during the 2 years after surgery decreased by 3.1 (P < 0.01); while minutes per game decreased by 5.2 (P < 0.001). Twenty-one percent (n = 5 of 24) of the players treated with microfracture did not return to competition in an NBA game. On return to competition player performance and minutes per game are diminished.

Nutritional intake in soccer players of different ages.

PubMed

Ruiz, Fátima; Irazusta, Amaia; Gil, Susana; Irazusta, Jon; Casis, Luis; Gil, Javier

2005-03-01

The purpose of this study was to evaluate the dietary practices of soccer players of different ages. The diets of the members of four soccer teams (mean ages of 14.0, 15.0, 16.6 and 20.9 years, respectively) were examined. Our results show that the caloric intake per kilogram of body mass was significantly higher among the youngest players when compared with the adult players (P < 0.05). The contribution of carbohydrates to total energy intake was lower than that recommended for athletes. This contribution decreased with age from 47.4% of total energy intake for the 14-year-olds to 44.6% for the adult players. No significant differences in protein or total fat intake were detected among the teams examined. Overall, our results show that the nutritional intake of the soccer players was not optimal, and that this intake was poorer among the adult players than among the adolescents. On the basis of our results, we recommended that nutritional education should be given to soccer players at an early age and should continue throughout adolescence, not only with a view to improving performance but also to promoting more healthy dietary practices in the long term.

Intrinsic risk factors of noncontact ankle sprains in soccer: a prospective study on 100 professional players.

PubMed

Fousekis, Konstantinos; Tsepis, Elias; Vagenas, George

2012-08-01

Ankle sprain is an extremely common injury in soccer players. Despite extensive research, the intrinsic cause of this injury under noncontact conditions remains unclear. To identify intrinsic risk factors for noncontact ankle sprains in professional soccer players. Cohort study; Level of evidence, 2 One hundred professional soccer players were assessed in the preseason for potential risk factors of noncontact ankle sprains. The assessment included (A) ankle joint asymmetries (right-left) in isokinetic muscle strength, flexibility, proprioception, and stability; (B) somatometric asymmetries; (C) previous injuries; and (D) lateral dominance traits. Noncontact ankle sprains were prospectively recorded and diagnosed for a full competition period (10 months). Seventeen of the players sustained at least 1 noncontact ankle sprain. Logistic regression revealed that players with (A) eccentric isokinetic ankle flexion strength asymmetries (odds ratio [OR] = 8.88; 95% confidence interval [CI], 1.95-40.36, P = .005), (B) increased body mass index (OR = 8.16; 95% CI, 1.42-46.63, P = .018), and (C) increased body weight (OR = 5.72; 95% CI, 1.37-23.95, P = .017 ) each had a significantly higher risk of a noncontact ankle sprain. A trend for younger players (OR = 0.28; 95% CI, 0.061-1.24, P = .092) and for players with ankle laxity asymmetries (OR = 3.38; 95% CI, 0.82-14.00, P = .093) to be at greater risk for ankle sprain was also apparent to the limit of statistical significance (.05 < P < .10). Functional strength asymmetries of the ankle flexors and increased body mass index and body weight raise the propensity for ankle sprains in professional soccer players. Age and asymmetries in ankle laxity are potential factors worth revisiting, as there was an indication for younger players and players with ankle instability to be at higher risk for ankle injury. Proper preseason evaluation may improve prevention strategies for this type of injury in soccer.

Does Education Matter? Major League Baseball Players and Longevity

ERIC Educational Resources Information Center

Kalist, David E.; Peng, Yingwei

2007-01-01

The authors used duration analysis to examine the longevity of Major League Baseball players. Using data on players who were born between 1945 and 1964, the authors found that the hazard rate of death for players who only attended high school was almost 2.0 times higher than those players who attended a 4-year university, evidence that the…

Executive Functions Predict the Success of Top-Soccer Players

PubMed Central

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. PMID:22496850

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

PubMed

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.

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

PubMed Central

Topič, Mojca Doupona; Šibila, Marko

2016-01-01

Abstract 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. PMID:28149349

The appropriateness of training exposures for match-play preparation in adolescent schoolboy and academy rugby union players.

PubMed

Phibbs, Padraic J; Jones, Ben; Read, Dale B; Roe, Gregory A B; Darrall-Jones, Joshua; Weakley, Jonathon J S; Rock, Andrew; Till, Kevin

2018-03-01

The aim of this study was to compare the physical and movement demands between training and match-play in schoolboy and academy adolescent rugby union (RU) players. Sixty-one adolescent male RU players (mean ± SD; age 17.0 ± 0.7 years) were recruited from four teams representing school and regional academy standards. Players were categorised into four groups based on playing standard and position: schoolboy forwards (n = 15), schoolboy backs (n = 15), academy forwards (n = 16) and academy backs (n = 15). Global positioning system and accelerometry measures were obtained from training and match-play to assess within-group differences between conditions. Maximum data were analysed from 79 match files across 8 matches (1.3 ± 0.5 matches per participant) and 152 training files across 15 training sessions (2.5 ± 0.5 training sessions per participant). Schoolboy forwards were underprepared for low-intensity activities experienced during match-play, with schoolboy backs underprepared for all movement demands. Academy forwards were exposed to similar physical demands in training to matches, with academy backs similar to or exceeding values for all measured variables. Schoolboy players were underprepared for many key, position-specific aspects of match-play, which could place them at greater risk of injury and hinder performance, unlike academy players who were better prepared.

Head Impact Exposure in Junior and Adult Australian Football Players

PubMed Central

King, Doug; Dempsey, Alasdair; Murphy, Myles

2018-01-01

This study measured and compared the frequency, magnitude, and distribution of head impacts sustained by junior and adult Australian football players, respectively, and between player positions over a season of games. Twelve junior and twelve adult players were tracked using a skin-mounted impact sensor. Head impact exposure, including frequency, magnitude, and location of impacts, was quantified using previously established methods. Over the collection period, there were no significant differences in the impact frequency between junior and adult players. However, there was a significant increase in the frequency of head impacts for midfielders in both grades once we accounted for player position. A comparable amount of head impacts in both junior and adult players has implications for Australian football regarding player safety and medical coverage as younger players sustained similar impact levels as adult players. The other implication of a higher impact profile within midfielders is that, by targeting education and prevention strategies, a decrease in the incidence of sports-related concussion may result. PMID:29805979

Identifying key areas for active interprofessional learning partnerships: A facilitated dialogue.

PubMed

Steven, Kathryn; Angus, Allyson; Breckenridge, Jenna; Davey, Peter; Tully, Vicki; Muir, Fiona

2016-11-01

Student and service user involvement is recognised as an important factor in creating interprofessional education (IPE) opportunities. We used a team-based learning approach to bring together undergraduate health professional students, early career professionals (ECPs), public partners, volunteers, and carers to explore learning partnerships. Influenced by evaluative inquiry, this qualitative study used a free text response to allow participants to give their own opinion. A total of 153 participants (50 public partners and 103 students and professionals representing 11 healthcare professions) took part. Participants were divided into mixed groups of six (n = 25) and asked to identify areas where students, professionals, and public could work together to improve health professional education. Each group documented their discussions by summarising agreed areas and next steps. Responses were collected and transcribed for inductive content analysis. Seven key themes (areas for joint working) were identified: communication, public as partners, standards of conduct, IPE, quality improvement, education, and learning environments. The team-based learning format enabled undergraduate and postgraduate health professionals to achieve consensus with public partners on areas for IPE and collaboration. Some of our results may be context-specific but the approach is generalisable to other areas.

Analysis of age, stature, body mass, BMI and quality of elite soccer players from 4 European Leagues.

PubMed

Bloomfield, J; Polman, R; Butterly, R; O'Donoghue, P

2005-03-01

The aim was to identify which league (English Premier League, Spanish La Liga Division, Italian Serie A and German Bundesliga) contained the highest quality players and whether differences in age, stature, body mass and BMI existed between the different positions in different leagues. Data were collected concerning 2,085 professional soccer players playing in these 4 leagues during the 2001-2002 season. Player quality was determined by the leagues' number of international players and their nations' FIFA World Ranking (FWR). The La Liga Division contained the highest quality players (mean FWR) (11.5+/-13.8), followed by the Serie A (13.3+/-21.3), the Premier League (30.6+/-27.3) and the Bundesliga (30.7+/-27.1), respectively. Also, differences were found between the age, stature, body mass and BMI of players in different positions and in the different leagues. Age had a significant influence on position with goalkeepers (years) (27.4+/-5.3) being older than midfielders (26.2+/-4.3) and forwards (25.8+/-4.2) and defenders (26.8+/-4.3) being older than forwards. Players from the Bundesliga had the greatest stature (m) (1.83+/-0.06), body mass (kg) (77.5+/-6.4) and BMI (kg x m(-2)) (23.2+/-1.1) of the 4 leagues. In reflection, La Liga's players had the shortest stature (1.80+/-0.06) and the Serie A players had the least body mass (74.3+/-5.4) and BMI (22.8+/-1.1). The differences discovered suggest either differences in playing style and physical demands of the different leagues, different physical conditioning methods or, alternatively, that there are desirable characteristics of players with teams in all 4 leagues seeking such players.

Abnormal findings on knee magnetic resonance imaging in asymptomatic NBA players.

PubMed

Walczak, Brian E; McCulloch, Patrick C; Kang, Richard W; Zelazny, Anthony; Tedeschi, Fred; Cole, Brian J

2008-01-01

The purpose of this study was to evaluate the knees of asymptomatic National Basketball Association (NBA) players via magnetic resonance imaging (MRI) and confirm or dispute findings reported in the previous literature. It is thought that a variety of significant abnormalities affecting the knee exist in asymptomatic patients and that these findings can be accurately identified on MRI. Two months prior to the 2005 season, bilateral knee MRI examinations of 14 asymptomatic NBA players (28 knees) were evaluated for abnormalities of the articular cartilage, menisci, and patellar and quadriceps tendons. The presence of joint effusion, subchondral edema, and cystic lesions and the integrity of the collateral and cruciate ligaments were also assessed.

Short Duration Heat Acclimation in Australian Football Players

PubMed Central

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 < 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. 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

Short Duration Heat Acclimation in Australian Football Players.

PubMed

Kelly, Monica; Gastin, Paul B; Dwyer, Daniel B; Sostaric, Simon; Snow, Rodney J

2016-03-01

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 < 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. Key pointsSome 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

The Impact and Functional Outcomes of Achilles Tendon Pathology in National Basketball Association Players

PubMed Central

Amin, Nirav H; McCullough, Kirk C; Mills, Gavin L; Jones, Morgan H; Cerynik, Douglas L; Rosneck, James; Parker, Richard D

2017-01-01

Achilles tendon rupture within professional athletes has been shown to lead to devastating consequences regarding return to athletic performance. Not only can this devastating injury affect performance for the remainder of player's career, it frequently becomes a career-ending event. Considering these significant risks associated with complete rupture, the purpose of this study was to evaluate NBA players with a spectrum of reported Achilles tendon pathology, from tendinopathy (insertional and non-insertional) to complete rupture. Between the 1988-1989 and 2010-2011 NBA seasons, we identified 43 cases of Achilles tendon pathology treated non-operatively. A control group was matched for the players able to return to play with the following parameters: age, position played, number of seasons played in the league, and similarly rated career performance statistics. Considering the medical staff, trainers and facilities available to a professional athlete, a “weekend warrior” should be counseled that even in optimal conditions, 14% of NBA players were unable to return to function/play after Achilles tendinopathy, and that those who were able to return did so at a decreased level of performance. In conclusion, players with Achilles tendinopathy have a better chance to return if they are younger in age and early in their professional career. Furthermore, the association between Achilles pathology and decline in player performance is an important message to convey to coaching staff and team management to allow properly informed decisions when these conditions arise. PMID:29082269

The Impact and Functional Outcomes of Achilles Tendon Pathology in National Basketball Association Players.

PubMed

Amin, Nirav H; McCullough, Kirk C; Mills, Gavin L; Jones, Morgan H; Cerynik, Douglas L; Rosneck, James; Parker, Richard D

2016-09-01

Achilles tendon rupture within professional athletes has been shown to lead to devastating consequences regarding return to athletic performance. Not only can this devastating injury affect performance for the remainder of player's career, it frequently becomes a career-ending event. Considering these significant risks associated with complete rupture, the purpose of this study was to evaluate NBA players with a spectrum of reported Achilles tendon pathology, from tendinopathy (insertional and non-insertional) to complete rupture. Between the 1988-1989 and 2010-2011 NBA seasons, we identified 43 cases of Achilles tendon pathology treated non-operatively. A control group was matched for the players able to return to play with the following parameters: age, position played, number of seasons played in the league, and similarly rated career performance statistics. Considering the medical staff, trainers and facilities available to a professional athlete, a "weekend warrior" should be counseled that even in optimal conditions, 14% of NBA players were unable to return to function/play after Achilles tendinopathy, and that those who were able to return did so at a decreased level of performance. In conclusion, players with Achilles tendinopathy have a better chance to return if they are younger in age and early in their professional career. Furthermore, the association between Achilles pathology and decline in player performance is an important message to convey to coaching staff and team management to allow properly informed decisions when these conditions arise.

High School Rugby Players' Perception of Coaching Effectiveness

ERIC Educational Resources Information Center

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…

Throwing speed and accuracy in baseball and cricket players.

PubMed

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.

Relationship Between Pretraining Subjective Wellness Measures, Player Load, and Rating-of-Perceived-Exertion Training Load in American College Football.

PubMed

Govus, Andrew D; Coutts, Aaron; Duffield, Rob; Murray, Andrew; Fullagar, Hugh

2018-01-01

The relationship between pretraining subjective wellness and external and internal training load in American college football is unclear. To examine the relationship of pretraining subjective wellness (sleep quality, muscle soreness, energy, wellness Z score) with player load and session rating of perceived exertion (s-RPE-TL) in American college football players. Subjective wellness (measured using 5-point, Likert-scale questionnaires), external load (derived from GPS and accelerometry), and s-RPE-TL were collected during 3 typical training sessions per week for the second half of an American college football season (8 wk). The relationship of pretraining subjective wellness with player load and s-RPE training load was analyzed using linear mixed models with a random intercept for athlete and a random slope for training session. Standardized mean differences (SMDs) denote the effect magnitude. A 1-unit increase in wellness Z score and energy was associated with trivial 2.3% (90% confidence interval [CI] 0.5, 4.2; SMD 0.12) and 2.6% (90% CI 0.1, 5.2; SMD 0.13) increases in player load, respectively. A 1-unit increase in muscle soreness (players felt less sore) corresponded to a trivial 4.4% (90% CI -8.4, -0.3; SMD -0.05) decrease in s-RPE training load. Measuring pretraining subjective wellness may provide information about players' capacity to perform in a training session and could be a key determinant of their response to the imposed training demands American college football. Hence, monitoring subjective wellness may aid in the individualization of training prescription in American college football players.

Suitability of FIFA's "The 11" Training Programme for Young Football Players - Impact on Physical Performance.

PubMed

Kilding, Andrew E; Tunstall, Helen; Kuzmic, Dejan

2008-01-01

There is a paucity of evidence regarding the use of injury prevention programmes for preadolescents participating in sport. "The 11 "injury prevention programme was developed by FIFA's medical research centre (F-MARC) to help reduce the risk of injury in football players aged 14 years and over. The aim of this study was to determine the suitability and effectiveness of "The 11 "for younger football players. Twenty-four [12 experimental (EXP), 12 control (CON)] young football players (age 10.4 ± 1.4 yr) participated. The EXP group followed "The 11 "training programme 5 days per week, for 6 weeks, completing all but one of the 10 exercises. Prior to, and after the intervention, both EXP and CON groups performed a battery of football-specific physical tests. Changes in performance scores within each group were compared using independent t-tests (p ≤ 0.05). Feedback was also gathered on the young players' perceptions of "The 11". No injuries occurred during the study in either group. Compliance to the intervention was 72%. Measures of leg power (3 step jump and counter-movement jump) increased significantly (3.4 and 6.0% respectively, p < 0.05). Speed over 20 m improved by 2% (p < 0.05). Most players considered "The 11 "beneficial but not enjoyable in the prescribed format. Given the observed improvements in the physical abilities and the perceived benefits of "The 11", it would appear that a modified version of the programme is appropriate and should be included in the training of young football players, for both physical development and potential injury prevention purposes, as well as to promote fair play. To further engage young football players in such a programme, some modification to "The 11 "should be considered. Key pointsChildren who participate in recreational and competitive sports, especially football, are susceptible to injury.There is a need for the design and assessment of injury prevention programmes for children.The 11 "improves essential physical

Whole-Person Impairment in Younger Retired NFL Players

PubMed Central

Domb, Benjamin G.; Carter, Chris; Finch, Nathan A.; Hammarstedt, Jon E.; Dunne, Kevin F.; Stake, Christine E.

2014-01-01

Background: Professional American football is a physically demanding, high-impact sport with an elevated risk of injury. Orthopaedic injuries may impose acute, short-term or cumulative consequences throughout a player’s lifetime. Several studies have addressed health and psychosocial concerns of an older, retired population of players in the National Football League (NFL); however, minimal research has examined the orthopaedic toll on younger, retired players. Purpose: This study reports total whole-person impairment (WPI) percentages in a cohort of younger, retired NFL players who presented for disability evaluations based on the use of standardized American Medical Association (AMA) impairment guidelines. Study Design: Case series; Level of evidence, 4. Methods: During the study period of February 2011 to August 2013, 65 younger retired NFL players presented for impairment evaluations. The mean time between retirement and impairment evaluation was 3.1 years (range, 0.3-16.4 years). A complete history and physical examination was performed on all symptomatic joints. A retrospective chart review was conducted on 100% of presenting players to assess orthopaedic burden. Body-part impairment (BPI) percentage for each affected joint was generated. The impairment data for each extremity were then combined with spine impairment data to create WPI percentage. Player demographics, including age, position, and playing time, were also recorded. Results: The average WPI percentage was 37% (range, 19%-53%). Players participating in >30 games (n = 54) had a higher mean WPI percentage (38%) than those playing in <30 games (31%; n = 11) (P = .004). Players competing in >5 seasons (n = 46) were 2.4 times more likely to have a WPI of at least 37% (P = .007). The most common joints players reported as symptomatic were lumbar (n = 63; 97%) and cervical spine (n = 58; 89%). The mean age at evaluation was 33.5 years (range, 27-42 years), and the mean number of seasons played was 7

Groin pain and soccer players: male versus female occurrence.

PubMed

Karlsson, M K; Dahan, R; Magnusson, H; Nyquist, F; Rosengren, B E

2014-08-01

Groin pain is common in soccer players. Comparison of results from different studies, especially between genders, is difficult as studies use different definitions and data collection procedures. Therefore we conducted a study of both male and female soccer players enabling direct gender comparison. The study enrolled 479 male soccer players aged 25 years (17-43) (mean with range) and 144 female soccer players aged 23 years (16-47), who answered a mailed questionnaire that included specific questions on groin pain and sports history. Data are presented as proportions (%) or as mean with 95% confidence intervals (95% CI). Groin pain was experienced by 55% of male soccer players and 28% of female soccer players, resulting in an odds ratio (OR) of 2.9 (95% CI 1.9, 4.5). Groin pain occurred more often in the preseason, than during the rest of the season in both male and female players (both P<0.001). Playing position in the team or playing league did not seem to influence the risk of suffering groin pain. In soccer players, male gender and preseasonal training appear to be risk factors for developing groin pain.

Decreased interlimb differences in female basketball players.

PubMed

Akpinar, Selcuk

2016-12-01

Hand preference can be influenced by some factors like sensory information and sports participation. In many sports, it is always desirable to have the similar performance of both hands to adapt to the fast changes of the game. Elite basketball players use their left non-dominant hand more accurately and more frequently during the game compared to amateurs. However, there is no quantitative data to explain this phenomenon. The aim of the study was to test whether participation of long-term basketball training influences interlimb difference and also observed more accurate and more frequent usage of the non-dominant hand in basketball players that can be explained by some kinematic variables during an aiming task. Professional right-handed female basketball players and age-matched non-athletes were asked to reach one of three targets in a virtual reality environment setup with either their non-dominant or dominant hand. Two kinematic parameters depicting motor performance asymmetries were measured: accuracy and hand path deviation from linearity (HPDL). No interlimb differences for basketball players but significant asymmetrical performance for non-athletes were observed. Although the aiming task used in this study is not a basketball specific task, basketball players still displayed better performance compared to non-athletes in both accuracy and HPDL. The current study implies that not only sensorimotor information but also participation of long-term sports activity can modify interlimb difference. Moreover, basketball players having symmetrical motor performance of both hands, which was found in this study, can indirectly explain the more frequent usage of the non-dominant left hand in basketball players.

Protective equipment use among female rugby players.

PubMed

Comstock, R Dawn; Fields, Sarah K; Knox, Christy L

2005-07-01

Our objective was to assess the prevalence of protective equipment use and the motivation for using protective equipment among a sample of US female rugby players. We surveyed a convenience sample of 234 current US female rugby players from 14 teams participating in a US women's rugby tournament, obtaining self-reported demographic, rugby exposure, and protective equipment use information. Mouthguards were the most commonly used piece of protective equipment: 90.8% of players reported having always worn a mouthguard while playing or practicing rugby within their most recent 3 months of play. Fewer than 15% of players reported having always worn other types of protective equipment. Equipment use varied by playing position. Whereas over 80% of players in all other positions always wore a mouthguard, 66.7% of scrum halves reported always wearing one. Both backs and forwards reported wearing shoulder pads, but only forwards reported always wearing padded headgear. Mouthguards, padded headgear, and shoulder pads were worn "to prevent injury," whereas ankle braces, neoprene sleeves, and athletic tape on joints were worn "to protect a current/recent injury." This is the first study of female rugby players to assess the prevalence of protective equipment use by playing position and the motivation for using protective equipment. With the exception of mouthguards, US female rugby players infrequently use protective equipment. Protective equipment use varies by playing position. Some types of protective equipment appear to be used as primary prevention mechanisms, whereas others are used as secondary or tertiary prevention mechanisms.

The upper values of plasma creatine kinase of professional soccer players during the Brazilian National Championship.

PubMed

Lazarim, Fernanda L; Antunes-Neto, Joaquim M F; da Silva, Fernando O C; Nunes, Lázaro A S; Bassini-Cameron, Adriana; Cameron, Luiz-Cláudio; Alves, Armindo A; Brenzikofer, René; de Macedo, Denise Vaz

2009-01-01

The current schedule of the Brazilian Soccer Championship may not give players enough recovery time between games. This could increase the chances of muscle damage and impaired performance. We hypothesized that plasma creatine kinase (CK) activity could be a reliable indirect marker of muscle overload in soccer players, so we sought to identify the reference values for upper limits of CK activity during a real-life elite competition. This study analyzed changes in plasma CK activity in 128 professional soccer players at different times during the Brazilian Championship. The upper limits of the 97.5th and 90th percentiles determined for CK activity were 1.338U/L and 975U/L, respectively, markedly higher than values previously reported in the literature. We also evaluated a team monthly throughout the Championship. The upper limit of the 90th percentile, 975U/L, was taken as the decision limit. Six players showing plasma CK values higher than this were asked to decrease their training for 1 week. These players presented lower CK values afterwards. Only one player with a CK value higher than the decision limit (1800U/L 1 day before a game) played on the field and was unfortunately injured during the game. The CK activity in all the other players showed a significant decrease over the course of the Championship, and the values became more homogeneous at the end. The results presented here suggest that plasma CK upper limit values can be used as a practical alternative for early detection of muscle overload in competing soccer players.

Descriptive profile of hip rotation range of motion in elite tennis players and professional baseball pitchers.

PubMed

Ellenbecker, Todd S; Ellenbecker, Gail A; Roetert, E Paul; Silva, Rogerio Teixeira; Keuter, Greg; Sperling, Fabio

2007-08-01

Repetitive loading to the hip joint in athletes has been reported as a factor in the development of degenerative joint disease and intra-articular injury. Little information is available on the bilateral symmetry of hip rotational measures in unilaterally dominant upper extremity athletes. Side-to-side differences in hip joint range of motion may be present because of asymmetrical loading in the lower extremities of elite tennis players and professional baseball pitchers. Cohort (cross-sectional) study (prevalence); Level of evidence, 1. Descriptive measures of hip internal and external rotation active range of motion were taken in the prone position of 64 male and 83 female elite tennis players and 101 male professional baseball pitchers using digital photos and computerized angle calculation software. Bilateral differences in active range of motion between the dominant and nondominant hip were compared using paired t tests and Bonferroni correction for hip internal, external, and total rotation range of motion. A Pearson correlation test was used to test the relationship between years of competition and hip rotation active range of motion. No significant bilateral difference (P > .005) was measured for mean hip internal or external rotation for the elite tennis players or the professional baseball pitchers. An analysis of the number of subjects in each group with a bilateral difference in hip rotation greater than 10 degrees identified 17% of the professional baseball pitchers with internal rotation differences and 42% with external rotation differences. Differences in the elite male tennis players occurred in only 15% of the players for internal rotation and 9% in external rotation. Female subjects had differences in 8% and 12% of the players for internal and external rotation, respectively. Statistical differences were found between the mean total arc of hip range of internal and external rotation in the elite tennis players with the dominant side being greater

Attitudes towards protective headgear in UK rugby union players

PubMed Central

Rumbold, James L; Olusoga, Peter

2017-01-01

Background/aim Concussions in rugby union pose a major threat to player welfare. Research has found protective headgear offers no significant protection against concussions but suggests a large proportion of players perceive headgear to be effective in preventing concussions. This study aimed to explore UK rugby union players’ attitudes towards wearing protective headgear. Methods 545 rugby union players (85% male) from a range of playing standards completed an online survey. Quantitative and qualitative data were collected on player attitudes towards protective headgear use. Descriptive statistics, multiple regressions and content analysis were used to analyse the responses. Results 37% of players believed that headgear was effective in preventing head injuries. Playing group was found to be inversely associated with headgear effectiveness (∆R2=0.01, B=−0.13, p=0.02), with youth players holding stronger beliefs that headgear is effective at preventing head injuries compared with all senior groups. The main reasons cited for wearing headgear related to protection from minor injuries (55%) with only 10% of responses related to concussion prevention. Conclusions There appears to be a good awareness in UK players that protective headgear is not effective at preventing concussions. Continued education is vital to ensure players are fully aware of the limitations of headgear, and players who wear it do not engage in overly reckless behaviours as a result. PMID:29081983

Adolescent Identities and Sexual Behavior: An Examination of Anderson's Player Hypothesis

ERIC Educational Resources Information Center

Giordano, Peggy C.; Longmore, Monica A.; Manning, Wendy D.; Northcutt, Miriam J.

2009-01-01

We investigate the social and behavioral characteristics of male adolescents who self-identify as players, focusing particularly on Anderson's claim that this social role is inextricably linked with poverty and minority status. Results indicate that black respondents, those affiliated with liberal peers and young men who initially report a…

Influence of players' physique on rugby football injuries.

PubMed Central

Lee, A J; Myers, J L; Garraway, W M

1997-01-01

OBJECTIVES: To determine whether there is an association between a player's physique and injuries incurred while playing rugby football. METHODS: A cohort study was carried out involving all senior rugby clubs in the Scottish Borders during the 1993-1994 rugby season. Somatotype estimates were determined for 1152 (95%) of the 1216 eligible players. Body mass index (BMI), chest to waist ratio, and the ponderal index (PI) were used to classify players' physique as endomorphic (obese), mesomorphic (muscular), and ectomorphic (linear). RESULTS: A strong association was found between physique and age (chi 2 test: chi 2 = 317.2, df = 10, P < 0.0001). More younger players were ectomorphs. Older players were more often endomorphic. The physiques of forwards and backs were significantly different (chi 2 test: chi 2 = 58.6, df = 2, P < 0.0001), with forwards being of a heavier build than three-quarters, even after adjustment for age. Endomorphic players were more likely than ectomorphs to be injured in a match after adjustment for age (age-adjusted mean BMI for players who were injured in a match was 25.4 compared with 24.6 for players who were not injured in a match, P < 0.0001; adjusted chest to waist ratio means were 1.136 and 1.125 respectively, P = 0.0307; adjusted PI means were 0.414 and 0.417 respectively, P = 0.0056). Increased risk of injury may occur when players play out of position, since one fifth of all injuries occurred in this circumstance. CONCLUSIONS: Further research needs to be conducted using a more objective method of measuring somatotype on a further cohort of players so that the risk of injury for different body types can be examined more closely and related to other potential confounding factors. The level of increased risk for individuals playing out of their usual playing position needs to be established with a greater degree of certainty. PMID:9192128

Strength asymmetry of the shoulders in elite volleyball players.

PubMed

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

Is the technical performance of young soccer players influenced by hormonal status, sexual maturity, anthropometric profile, and physical performance?

PubMed

Moreira, Alexandre; Massa, Marcelo; Thiengo, Carlos R; Rodrigues Lopes, Rafael Alan; Lima, Marcelo R; Vaeyens, Roel; Barbosa, Wesley P; Aoki, Marcelo S

2017-12-01

The aim of this study was to examine the influence of hormonal status, anthropometric profile, sexual maturity level, and physical performance on the technical abilities of 40 young male soccer players during small-sided games (SSGs). Anthropometric profiling, saliva sampling, sexual maturity assessment (Tanner scale), and physical performance tests (Yo-Yo and vertical jumps) were conducted two weeks prior to the SSGs. Salivary testosterone was determined by the enzyme-linked immunosorbent assay method. Technical performance was determined by the frequency of actions during SSGs. Principal component analyses identified four technical actions of importance: total number of passes, effectiveness, goal attempts, and total tackles. A multivariate canonical correlation analysis was then employed to verify the prediction of a multiple dependent variables set (composed of four technical actions) from an independent set of variables, composed of testosterone concentration, stage of pubic hair and genitalia development, vertical jumps and Yo-Yo performance. A moderate-to-large relationship between the technical performance set and the independent set was observed. The canonical correlation was 0.75 with a canonical R 2 of 0.45. The highest structure coefficient in the technical performance set was observed for tackles (0.77), while testosterone presented the highest structure coefficient (0.75) for the variables of the independent set. The current data suggest that the selected independent set of variables might be useful in predicting SSG performance in young soccer players. Coaches should be aware that physical development plays a key role in technical performance to avoid decision-making mistakes during the selection of young players.

Physical and temporal characteristics of under 19, under 21 and senior male beach volleyball players.

PubMed

Medeiros, Alexandre; Marcelino, Rui; Mesquita, Isabel; Palao, José Manuel

2014-09-01

This study aimed to assess the effects of age groups and players' role (blocker vs. defender specialist) in beach volleyball in relation to physical and temporal variables, considering quality of opposition. 1101 rallies from Under 19 (U19), 933 rallies from Under 21 (U21), and 1480 rallies from senior (senior) (Men's Swatch World Championships, 2010-2011) were observed using video match analysis. Cluster analysis was used to set teams' competitive levels and establish quality of opposition as "balanced", "moderate balanced" and "unbalanced" games. The analyzed variables were: temporal (duration of set, total rest time, total work time, duration of rallies, rest time between rallies) and physical (number of jumps and number of hits done by defenders and blockers) characteristics. A one-way ANOVA, independent samples t-test and multinomial logistic regression were performed to analyze the variables studied. The analysis of temporal and physical characteristics showed differences considering age group, player's role and quality of opposition. The duration of set, total rest time, and number of jumps done by defenders significantly increased from the U19 to senior category. Multinomial logistic regression showed that in: a) balanced games, rest time between rallies was higher in seniors than in U19 or U21; number of jumps done by defenders was higher in seniors than in U19) and U21; b) moderate balanced games, number of jumps done by defenders was higher in seniors than in U21 and number of jumps done by blockers was smaller in U19 than U21 or seniors; c) unbalanced games, no significant findings were shown. This study suggests differences in players' performances according to age group and players' role in different qualities of opposition. The article provides reference values that can be useful to guide training and create scenarios that resemble a competition, taking into account physical and temporal characteristics. Key PointsPlayer roles, quality of opposition

Who Pays to Play Freemium Games? The Profiles and Motivations of Players Who Make Purchases Within Social Casino Games

PubMed Central

Gainsbury, Sally M.; King, Daniel L.; Russell, Alex M. T.; Delfabbro, Paul

2016-01-01

Background and aims Social casino games (SCGs) feature gambling themes and are typically free to download and play with optional in-game purchases. Although few players spend money, this is sufficient to make them profitable for game developers. Little is known about the profile and motivations of paying players as compared to non-paying players. Methods This study compared the characteristics of 521 paying and non-paying Australian social casino game players who completed an online survey. Results Paying players were more likely to be younger, male, speak a non-English language, and have a university education than non-payers. Paying players were more likely to be more highly involved in SCG in terms of play frequency and engagement with games and emphasized social interaction more strongly as a motivation for playing. A cluster analysis revealed distinct subgroups of paying players; these included more frequent moderate spenders who made purchases to avoid waiting for credits and to give gifts to friends as well as less frequent high spenders who made purchases to increase the entertainment value of the game. Discussion These findings suggest that paying players have some fundamental differences from non-paying players and high spenders are trying to maximize their enjoyment, while non-spenders are content with the game content they access. Conclusions Given the structural similarities between SCG and online gambling, understanding subgroups of players may have broader implications, including identifying characteristics of gamers who may also engage in gambling and players who may develop problems related to excessive online gaming. PMID:27306146

Who Pays to Play Freemium Games? The Profiles and Motivations of Players Who Make Purchases Within Social Casino Games.

PubMed

Gainsbury, Sally M; King, Daniel L; Russell, Alex M T; Delfabbro, Paul

2016-06-01

Background and aims Social casino games (SCGs) feature gambling themes and are typically free to download and play with optional in-game purchases. Although few players spend money, this is sufficient to make them profitable for game developers. Little is known about the profile and motivations of paying players as compared to non-paying players. Methods This study compared the characteristics of 521 paying and non-paying Australian social casino game players who completed an online survey. Results Paying players were more likely to be younger, male, speak a non-English language, and have a university education than non-payers. Paying players were more likely to be more highly involved in SCG in terms of play frequency and engagement with games and emphasized social interaction more strongly as a motivation for playing. A cluster analysis revealed distinct subgroups of paying players; these included more frequent moderate spenders who made purchases to avoid waiting for credits and to give gifts to friends as well as less frequent high spenders who made purchases to increase the entertainment value of the game. Discussion These findings suggest that paying players have some fundamental differences from non-paying players and high spenders are trying to maximize their enjoyment, while non-spenders are content with the game content they access. Conclusions Given the structural similarities between SCG and online gambling, understanding subgroups of players may have broader implications, including identifying characteristics of gamers who may also engage in gambling and players who may develop problems related to excessive online gaming.

Time-loss and non-time-loss injuries in youth football players.

PubMed

Dompier, Thomas P; Powell, John W; Barron, Mary J; Moore, Marguerite T

2007-01-01

Estimates suggest that more than 5.5 million youths play football annually, and 28% of youth football players (age range = 5 to 14 years) are injured each year, resulting in more than 187 000 emergency room visits. To analyze time-loss (TL) and non-time-loss (NTL) injury patterns across age groups in youth football players. Two-year observational cohort. Two midwestern communities, including players from the fourth through eighth grades and between the ages of 9 and 14 years. A total of 779 players participated, including 296 in grades 4 and 5; 203 in grade 6; 188 in grade 7; and 92 in grade 8. (Players in the fourth and fifth grades participated on the same teams, so we considered them as a single group.) Injury frequencies and exposures were collected by certified athletic trainers present at each practice and game and used to calculate injury rates with 95% confidence intervals (CIs) for both TL and NTL injuries across age groups. A total of 474 injuries and 26 565 exposures were identified. Injuries were reported by 36.5% of the players, with 14.4% reporting more than 1 injury in a season. The overall injury rate per 1000 athlete-exposures (A-Es) was 17.8 (95% CI = 16.3, 19.5). The injury rate increased with each succeeding grade from 14.3 per 1000 A-Es (95% CI = 12.1, 16.9) in grades 4 and 5 to 21.7 per 1000 A-Es (95% CI = 17.2, 27.3) in grade 8. A total of 58.6% of all injuries were NTL. Non-time-loss injuries accounted for 70.1% of the injuries reported by fourth and fifth graders, 55.1% by sixth graders, 64.0% by seventh graders, and 33.8% by eighth graders. The cumulative NTL injury rate was 10.5 per 1000 A-Es (95% CI = 9.3, 11.8), and the TL injury rate was 7.4 per 1000 A-Es (95% CI = 6.4, 8.5). Youth football players sustained more NTL injuries than TL injuries. We recommend that a first-aid-certified coach or league official be present at all games and practices.

Concussion among female middle-school soccer players.

PubMed

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

The epidemiology of foot injuries in professional rugby union players.

PubMed

Pearce, Christopher J; Brooks, John H M; Kemp, Simon P T; Calder, James D F

2011-09-01

Foot injuries represent a small but important proportion of injuries to professional rugby union players. There are no detailed epidemiological studies regarding these injuries. The aim of this study was to describe the epidemiology of foot injuries sustained by a cohort of professional rugby union players and identify areas that may be targeted for injury prevention in the future. Medical personnel prospectively recorded injuries in professional Premiership rugby union players in England over four seasons. Injuries to the foot were identified and the time away from training and playing was reported. A total of 147 foot injuries were sustained resulting in 3542 days of absence in total. Acute events accounted for 73% of all foot injuries, with chronic, mostly overuse conditions, accounting for 25% (undiagnosed 2%). Chronic conditions led to proportionately more time away from training and playing (p=<0.001). Specifically, stress fractures in the foot accounted for 8% of the total foot injuries but 22% of the absence. Navicular stress fractures had the longest recovery time with the mean return to training and match play of 188 days. In collision sports such as rugby, some injuries may be inevitable but clinicians should always be seeking ways to minimise their occurrence and impact. This study revealed a high proportion of morbidity associated with chronic and overuse foot injuries in these professional athletes. With greater attention paid to risk factors, some of these injuries, and importantly, recurrent injuries may be avoided. Copyright © 2010 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

Effects of small-sided games on physical conditioning and performance in young soccer players.

PubMed

Katis, Athanasios; Kellis, Eleftherios

2009-01-01

The purpose of this study was to examine, first, the movement actions performed during two different small-sided games and, second, their effects on a series of field endurance and technical tests. Thirty-four young soccer players (age: 13 ± 0.9 yrs; body mass: 62.3 ± 15.1 kg; height: 1.65 ± 0.06 m) participated in the study. Small-sided games included three-a-side (3 versus 3 players) and six-a-side (6 versus 6 players) games consisting of 10 bouts of 4 min duration with 3 min active recovery between bouts. Soccer player performance was evaluated using five field tests: a) 30m sprint, b) throw-in for distance, c) Illinois Agility Test, d) dribbling the ball and e) horizontal jump before, in the middle and after the implementation of both game situations. Heart rate was monitored during the entire testing session. Each game was also filmed to measure soccer movements within the game. The ANOVA analysis indicated that the three-a- side games displayed significantly higher heart rate values compared with the six-a-side games (p < 0.05). The number of short passes, kicks, tackles, dribbles and scoring goals were significantly higher during the three-a-side compared with the six-a-side game condition (p < 0. 05) while players performed more long passes and headed the ball more often during the six-a-side (p < 0.05). After the three-a-side games, there was a significant decline in sprint and agility performance (p < 0.05), while after both game conditions significant alterations in the throw-in and the horizontal jump performance were observed (p < 0.05). The results of the present study indicated that three-a-side games provide higher stimulus for physical conditioning and technical improvement than six-a-side games and their use for training young soccer players is recommended. Key pointsThree-a-side games display higher HR compared with six-a-side games.In the three-a-side games players performed more short passes, kicks, dribbles, tackles and scored more goals

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

PubMed

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.

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

PubMed Central

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

Training Patterns of Wheelchair Basketball Players in Turkey

ERIC Educational Resources Information Center

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…

Hydration and Fluid Replacement Knowledge, Attitudes, Barriers, and Behaviors of NCAA Division 1 American Football Players.

PubMed

Judge, Lawrence W; Kumley, Roberta F; Bellar, David M; Pike, Kim L; Pierson, Eric E; Weidner, Thomas; Pearson, David; Friesen, Carol A

2016-11-01

Judge, LW, Kumley, RF, Bellar, DM, Pike, KL, Pierson, EE, Weidner, T, Pearson, D, and Friesen, CA. Hydration and fluid replacement knowledge, attitudes, barriers, and behaviors of NCAA Division 1 American football players. J Strength Cond Res 30(11): 2972-2978, 2016-Hydration is an important part of athletic performance, and understanding athletes' hydration knowledge, attitudes, barriers, and behaviors is critical for sport practitioners. The aim of this study was to assess National Collegiate Athletic Association (NCAA) Division 1 (D1) American football players, with regard to hydration and fluid intake before, during, and after exercise, and to apply this assessment to their overall hydration practice. The sample consisted of 100 student-athletes from 2 different NCAA D1 universities, who participated in voluntary summer football conditioning. Participants completed a survey to identify the fluid and hydration knowledge, attitudes and behaviors, demographic data, primary football position, previous nutrition education, and barriers to adequate fluid consumption. The average Hydration Knowledge Score (HKS) for the participants in the present study was 11.8 ± 1.9 (69.4% correct), with scores ranging from 42 to 100% correct. Four key misunderstandings regarding hydration, specifically related to intervals of hydration habits among the study subjects, were revealed. Only 24% of the players reported drinking enough fluids before, during, immediately after, and 2 hours after practice. Generalized linear model analysis predicted the outcome variable HKS (χ = 28.001, p = 0.045), with nutrition education (Wald χ = 8.250, p = 0.041) and position on the football team (χ = 9.361, p = 0.025) being significant predictors. "Backs" (e.g., quarterbacks, running backs, and defensive backs) demonstrated significantly higher hydration knowledge than "Linemen" (p = 0.014). Findings indicated that if changes are not made to increase hydration awareness levels among football teams

The Impact of Moderate and High Intensity Total Body Fatigue on Passing Accuracy in Expert and Novice Basketball Players

PubMed Central

Lyons, Mark; Al-Nakeeb, Yahya; Nevill, Alan

2006-01-01

Despite the acknowledged importance of fatigue on performance in sport, ecologically sound studies investigating fatigue and its effects on sport-specific skills are surprisingly rare. The aim of this study was to investigate the effect of moderate and high intensity total body fatigue on passing accuracy in expert and novice basketball players. Ten novice basketball players (age: 23.30 ± 1.05 yrs) and ten expert basketball players (age: 22.50 ± 0.41 yrs) volunteered to participate in the study. Both groups performed the modified AAHPERD Basketball Passing Test under three different testing conditions: rest, moderate intensity and high intensity total body fatigue. Fatigue intensity was established using a percentage of the maximal number of squat thrusts performed by the participant in one minute. ANOVA with repeated measures revealed a significant (F 2,36 = 5.252, p = 0.01) level of fatigue by level of skill interaction. On examination of the mean scores it is clear that following high intensity total body fatigue there is a significant detriment in the passing performance of both novice and expert basketball players when compared to their resting scores. Fundamentally however, the detrimental impact of fatigue on passing performance is not as steep in the expert players compared to the novice players. The results suggest that expert or skilled players are better able to cope with both moderate and high intensity fatigue conditions and maintain a higher level of performance when compared to novice players. The findings of this research therefore, suggest the need for trainers and conditioning coaches in basketball to include moderate, but particularly high intensity exercise into their skills sessions. This specific training may enable players at all levels of the game to better cope with the demands of the game on court and maintain a higher standard of play. Key Points Aim: to investigate the effect of moderate and high intensity total body fatigue on

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

PubMed

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.

Creatine supplementation in high school football players.

PubMed

McGuine, T A; Sullivan, J C; Bernhardt, D T

2001-10-01

To describe creatine supplementation patterns and behaviors associated with creatine supplementation in high school football players. A cross-sectional, multisite, anonymous, descriptive survey was conducted between October 1999 and February 2000. 37 public high schools in Wisconsin. A total of 1,349 high school football players, grades 9-12. Self-reported prevalence of creatine use, as well as perceived benefits and risks. In addition, sources of information and influence regarding creatine supplementation were assessed. 30% of the respondents reported using creatine. Creatine use was lowest in the 9th grade (10.4%) and highest in the 12th grade (50.5%). 41% of the players at small schools stated they used creatine compared with 29% of the players in large schools. Enhanced recovery following a workout was the most likely perceived benefit of creatine supplementation, while dehydration was cited most often as a risk of creatine use. Users were encouraged to take creatine most often by their friends while their parents discouraged creatine use. Creatine use is widespread in high school football players. High school football players who use creatine may not be aware of the risks and benefits associated with creatine supplementation. Sports medicine professionals who work with this population need to educate athletes, coaches, and parents about the use of creatine as a performance-enhancing supplement.

Nutritional Intake of Young Italian High-Level Soccer Players: Under-Reporting is the Essential Outcome

PubMed Central

Caccialanza, Riccardo; Cameletti, Barbara; Cavallaro, Gianfranco

2007-01-01

It is recognized that much of the dietary data on adolescents and athletes is prone to reporting error, mostly through under-reporting. Nevertheless, in the majority of studies assessing the nutritional intake of young soccer players under-reporting has not been taken into consideration. The purpose of this study was to assess the dietary intake of a sample of young male Italian high-level soccer players on two time points to evaluate the degree of under- reporting. Seventy-five male high level soccer players (age range: 15-17 years) completed 4-day food records on two separate occasions (T0; T1, 3 months after T0). Under-reporting was assessed by the ratio of reported estimated energy intake (EEI) to estimated energy expenditure (EEE). Forty- three subjects, whose food records were judged accurate enough both at T0 and T1, were included in the data analysis (inclusion rate 57.3%). No significant weight changes were documented between T0 and T1 and in the two weeks preceding both T0 and T1. Reported mean daily energy intake was significantly lower than mean estimated daily energy expenditure both at T0 and T1 (p < 0.001). The average EEI/EEE ratio was 0.75 + 0.2 both at T0 and T1. It was ≤ 80% in 27 subjects (62.8%) at T0 and in 23 (53.4%) at T1; it reached 50% in 4 subjects both at T0 and T1. The degree of under- reporting of the young soccer players was in line with the available data on this age group. This study emphasizes that under-reporting is a critical issue in the evaluation of young athletes dietary intake, which should be considered in the interpretation of data, particularly when energy inadequacies are reported. Further studies with uniformed methods are needed, in order to reduce the degree of under-reporting, obtain reliable data on the dietary intake of young soccer players and evaluate the efficacy of targeted nutrition education programs. Key pointsUnder-reporting is a critical issue in the evaluation of young athletes’ dietary intake, which

Incidence and variance of knee injuries in elite college football players.

PubMed

Bradley, James; Honkamp, Nicholas J; Jost, Patrick; West, Robin; Norwig, John; Kaplan, Lee D

2008-06-01

Knee injuries are among the most common musculoskeletal injuries in US football players. The literature includes little information about the role of player position and risk for knee injury. We hypothesized that the incidence of knee injury in elite collegiate US football players is high and that type of injury varies by player position. We evaluated 332 elite collegiate US football players at the 2005 National Football League Combine. All players underwent radiographic examinations, including plain x-rays and/or magnetic resonance imaging when necessary. All knee pathologic conditions and surgical procedures were recorded. Data were analyzed by player position to detect any trends. Fifty-four percent (179) of the 332 players had a history of knee injury; knee injuries totaled 233 (1.3/player injured). Eighty-six players (25.9%) had a total of 114 surgeries. The most common injuries were medial collateral ligament injury (n = 79), meniscal injury (n = 51), and anterior cruciate ligament (ACL) injury (n = 40). The most common surgeries were arthroscopic meniscectomy (n = 39), ACL reconstruction (n = 35), and arthroscopic meniscal repair (n = 13). A history of knee injury was most common in defensive linemen (68% of players), tight ends (57%), and offensive linemen (57%). Knee surgery was more commonly performed on running backs (36%) and linebackers (34%). There were no significant associations between type or frequency of specific injuries with regard to player position. Knee injuries are common injuries in elite collegiate football players, and one fourth of these players undergo surgical procedures. However, there were no statistically significant differences in type or frequency of injuries by player position.

The evaluation of small-sided games as a talent identification tool in highly trained prepubertal soccer players.

PubMed

Fenner, Jonathan S J; Iga, John; Unnithan, Viswanath

2016-10-01

The aim of this study was to evaluate physiological and technical attributes of prepubertal soccer players during multiple small-sided games (SSGs), and determine if SSGs can act as a talent identification tool. Sixteen highly trained U10 soccer players participated and separated into two groups of eight. Each group played six small-sided (4 vs. 4) matches of 5-min duration. Each player was awarded total points for the match result and goals scored. A game technical scoring chart was used to rate each player's performance during each game. Time-motion characteristics were measured using micromechanical devices. Total points had a very large significant relationship with game technical scoring chart (r = 0.758, P < 0.001). High-speed running distance had a significantly large correlation with game technical scoring chart (r = 0.547, P < 0.05). Total distance covered had a significant and moderate correlation with game technical scoring chart (r = 0.545, P < 0.05) and total points (r = 0.438, P < 0.05). The results demonstrated a large agreement between the highest-rated players and success in multiple SSGs, possibly due to higher-rated players covering larger distances in total and at high speed. Consequently, multiple SSG could be used to identify the more talented prepubertal soccer players.

Who Are the Players in Canadian Curriculum?

ERIC Educational Resources Information Center

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…

Investigating the Nutritional and Recovery Habits of Tennis Players.

PubMed

Fleming, James A; Naughton, Robert J; Harper, Liam D

2018-04-03

In this study, the nutritional and recovery habits of tennis players pre-, during, and post-match-play were investigated. Seventy tennis players completed a bespoke nutrition and recovery habits questionnaire, with questions related to the following areas: match preparation, intra-match nutritional habits, situation dependent variables, and post-match nutrition and recovery. On match day-1, the consumption of balanced meals consisting of carbohydrate (CHO), fat and protein, with some micronutrient considerations were reported by 51% of players. On match-days, CHOs were prioritised prior to match-play with CHO dominant meals consumed by the majority of players. During matches, all players adopted a nutritional strategy, with water (94%), banana(s) (86%) and sports drinks (50%) commonly used. Carbohydrate rich nutritional aids, including sports drinks (80%) and energy gels (26%) were utilised more readily during long matches (>2 h). The day after match-play, 39% of players reported the consumption of "nothing specific". Multiple post-match recovery strategies were adopted by 80% of players, with foam rolling (77%), ice baths (40%), protein shake intake (37%) and hot baths (26%) most used. Findings indicate highly variable eating and recovery habits in tennis players pre-, during and post-match-play, with scope for improved practices.

Investigating the Nutritional and Recovery Habits of Tennis Players

PubMed Central

2018-01-01

In this study, the nutritional and recovery habits of tennis players pre-, during, and post-match-play were investigated. Seventy tennis players completed a bespoke nutrition and recovery habits questionnaire, with questions related to the following areas: match preparation, intra-match nutritional habits, situation dependent variables, and post-match nutrition and recovery. On match day-1, the consumption of balanced meals consisting of carbohydrate (CHO), fat and protein, with some micronutrient considerations were reported by 51% of players. On match-days, CHOs were prioritised prior to match-play with CHO dominant meals consumed by the majority of players. During matches, all players adopted a nutritional strategy, with water (94%), banana(s) (86%) and sports drinks (50%) commonly used. Carbohydrate rich nutritional aids, including sports drinks (80%) and energy gels (26%) were utilised more readily during long matches (>2 h). The day after match-play, 39% of players reported the consumption of “nothing specific”. Multiple post-match recovery strategies were adopted by 80% of players, with foam rolling (77%), ice baths (40%), protein shake intake (37%) and hot baths (26%) most used. Findings indicate highly variable eating and recovery habits in tennis players pre-, during and post-match-play, with scope for improved practices. PMID:29614035

Relative risk for concussions in young female soccer players.

PubMed

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 < .001, α = .05, CI = 95%). This demonstrates that the relative risk of probable concussions in young female soccer players is significantly higher than in a control group of nonsoccer players of the same sex and age.

Long non-coding RNAs as molecular players in plant defense against pathogens.

PubMed

Zaynab, Madiha; Fatima, Mahpara; Abbas, Safdar; Umair, Muhammad; Sharif, Yasir; Raza, Muhammad Ammar

2018-05-31

Long non-coding RNAs (lncRNAs) has significant role in of gene expression and silencing pathways for several biological processes in eukaryotes. lncRNAs has been reported as key player in remodeling chromatin and genome architecture, RNA stabilization and transcription regulation, including enhancer-associated activity. Host lncRNAs are reckoned as compulsory elements of plant defense. In response to pathogen attack, plants protect themselves with the help of lncRNAs -dependent immune systems in which lncRNAs regulate pathogen-associated molecular patterns (PAMPs) and other effectors. Role of lncRNAs in plant microbe interaction has been studied extensively but regulations of several lncRNAs still need extensive research. In this study we discussed and provide as overview the topical advancements and findings relevant to pathogen attack and plant defense mediated by lncRNAs. It is hoped that lncRNAs would be exploited as a mainstream player to achieve food security by tackling different plant diseases. Copyright © 2018. Published by Elsevier Ltd.

Motivational patterns as an instrument for predicting success in promising young football players.

PubMed

Zuber, Claudia; Zibung, Marc; Conzelmann, Achim

2015-01-01

Psychological characteristics are crucial to identifying talents, which is why these are being incorporated in today's multidimensional talent models. In addition to multidimensionality, talent studies are increasingly drawing on holistic theories of development, leading to the use of person-oriented approaches. The present study adopts such an approach by looking at the influence that motivational characteristics have on the development of performance, in a person-oriented way. For this purpose, it looks at how the constructs achievement motive, achievement goal orientation and self-determination interact with one another, what patterns they form and how these patterns are linked to subsequent sports success. Ninety-seven top young football players were questioned twice. Another year later, it was enquired which of these players had been selected for the U15 national team. At both measuring points, four patterns were identified, which displayed a high degree of structural and individual stability. As expected, the highly intrinsically achievement-oriented players were significantly more likely to move up into the U15 national team. The results point to the importance of favourable patterns of motivational variables in the form of specific types, for medium-term performance development among promising football talents, and thus provide valuable clues for the selection and promotion of those.

Relations between basic and specific motor abilities and player quality of young basketball players.

PubMed

Marić, Kristijan; Katić, Ratko; Jelicić, Mario

2013-05-01

Subjects from 5 first league clubs from Herzegovina were tested with the purpose of determining the relations of basic and specific motor abilities, as well as the effect of specific abilities on player efficiency in young basketball players (cadets). A battery of 12 tests assessing basic motor abilities and 5 specific tests assessing basketball efficiency were used on a sample of 83 basketball players. Two significant canonical correlations, i.e. linear combinations explained the relation between the set of twelve variables of basic motor space and five variables of situational motor abilities. Underlying the first canonical linear combination is the positive effect of the general motor factor, predominantly defined by jumping explosive power, movement speed of the arms, static strength of the arms and coordination, on specific basketball abilities: movement efficiency, the power of the overarm throw, shooting and passing precision, and the skill of handling the ball. The impact of basic motor abilities of precision and balance on specific abilities of passing and shooting precision and ball handling is underlying the second linear combination. The results of regression correlation analysis between the variable set of specific motor abilities and game efficiency have shown that the ability of ball handling has the largest impact on player quality in basketball cadets, followed by shooting precision and passing precision, and the power of the overarm throw.

Magnetic Resonance Imaging Findings in the Symptomatic Hips of Younger Retired National Football League Players.

PubMed

Domb, Benjamin G; Jackson, Timothy J; Carter, Christopher C; Jester, Jon R; Finch, Nathan A; Stake, Christine E

2014-07-01

American football players have an increased level of risk for hip injuries because of the high level of contact, biomechanical load, and anatomic strain placed on the hip joint. Many injuries are attributed to soft tissue injury rather than intra-articular lesions. However, because of improved imaging and increased knowledge, physicians are attributing unexplained hip pain to intra-articular lesions with increasing frequency. To assess the prevalence of pathologic intra-articular hip lesions in a younger, retired National Football League (NFL) player cohort evaluated for persistent hip pain. Case series; Level of evidence, 4. A retrospective chart review was performed of magnetic resonance imaging (MRI) on retired NFL players evaluated at an orthopaedic clinic for persistent hip pain. All MRIs were performed at the same location and reviewed by the same independent radiologist. The study included 62 hips; MRI was used to evaluate 27 hips, and MRI arthrogram was used to evaluate 35 hips. Images were assessed for labral tears, chondral lesions, ligamentum teres (LT) tears, bone cysts, osteophytes, loose bodies, trochanteric bursitis, and alpha angle. Player demographics, including position and seasons played, were recorded. From February 2011 to December 2012, a total of 50 retired players from the NFL (average age, 33 years; range, 27-39 years) received impairment evaluations assessing all symptomatic joints. Thirty-eight (76%) players had hip complaints and underwent a dedicated hip MRI. Twenty-four players (63%) had bilateral hip pain, for a total of 62 hips evaluated. There were 55 (89%) labral tears, 61 (98%) chondral lesions, and 50 (81%) partial or complete LT tears identified on MRI. Additional findings included 3 (5%) hips with osteophytes, 9 (14.5%) with subchondral bone cysts, and 3 (5%) with paralabral cysts. None of the players were found to have trochanteric bursitis or loose bodies. Fifty-eight of 62 alpha angles could be measured, for a mean of 59�

Colonic transit in soccer players.

PubMed

Sesboüé, B; Arhan, P; Devroede, G; Lecointe-Besançon, I; Congard, P; Bouchoucha, M; Fabre, J

1995-04-01

To evaluate the effects of exercise on colonic function, we measured total and segmental transit times in 11 male soccer players and nine male radiology student technicians. Diet was kept constant in all subjects, who maintained their normal activities. For the soccer players, normal activities included 15 h of training and one match each week. Transit times were measured with radioopaque markers, using the multiple-ingestion, single-radiograph technique. No overall difference in large bowel transit was observed between the two groups. Right colon transit was considerably slower in the soccer players, whereas left colon and rectal transit were slightly accelerated. We conclude that an intensive sport activity only modifies regional differences in large bowel function. This may be of importance in extreme conditions, such as those experienced by marathon runners. Data should be obtained before prescribing exercise to treat constipation.

Development of a risk prediction model among professional hockey players with visible signs of concussion.

PubMed

Bruce, Jared M; Echemendia, Ruben J; Meeuwisse, Willem; Hutchison, Michael G; Aubry, Mark; Comper, Paul

2017-04-04

Little research examines how to best identify concussed athletes. The purpose of the present study was to develop a preliminary risk decision model that uses visible signs (VS) and mechanisms of injury (MOI) to predict the likelihood of subsequent concussion diagnosis. Coders viewed and documented VS and associated MOI for all NHL games over the course of the 2013-2014 and 2014-2015 regular seasons. After coding was completed, player concussions were identified from the NHL injury surveillance system and it was determined whether players exhibiting VS were subsequently diagnosed with concussions by club medical staff as a result of the coded event. Among athletes exhibiting VS, suspected loss of consciousness, motor incoordination or balance problems, being in a fight, having an initial hit from another player's shoulder and having a secondary hit on the ice were all associated with increased risk of subsequent concussion diagnosis. In contrast, having an initial hit with a stick was associated with decreased risk of subsequent concussion diagnosis. A risk prediction model using a combination of the above VS and MOI was superior to approaches that relied on individual VS and associated MOI (sensitivity=81%, specificity=72%, positive predictive value=26%). Combined use of VS and MOI significantly improves a clinician's ability to identify players who need to be evaluated for possible concussion. A preliminary concussion prediction log has been developed from these data. Pending prospective validation, the use of these methods may improve early concussion detection and evaluation. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Decomposition of Multi-player Games

NASA Astrophysics Data System (ADS)

Zhao, Dengji; Schiffel, Stephan; Thielscher, Michael

Research in General Game Playing aims at building systems that learn to play unknown games without human intervention. We contribute to this endeavour by generalising the established technique of decomposition from AI Planning to multi-player games. To this end, we present a method for the automatic decomposition of previously unknown games into independent subgames, and we show how a general game player can exploit a successful decomposition for game tree search.

Activity Profiles in International Women's Team Handball Using PlayerLoad.

PubMed

Wik, Eirik H; Luteberget, Live S; Spencer, Matt

2017-08-01

Team handball matches place diverse physical demands on players, which may result in fatigue and decreased activity levels. However, previous speed-based methods of quantifying player activity may not be sensitive for capturing short-lasting team-handball-specific movements. To examine activity profiles of a women's team handball team and individual player profiles, using inertial measurement units. Match data were obtained from 1 women's national team in 9 international matches (N = 85 individual player samples), using the Catapult OptimEye S5. PlayerLoad/min was used as a measure of intensity in 5- and 10-min periods. Team profiles were presented as relative to the player's match means, and individual profiles were presented as relative to the mean of the 5-min periods with >60% field time. A high initial intensity was observed for team profiles and for players with ≥2 consecutive periods of play. Substantial declines in PlayerLoad/min were observed throughout matches for the team and for players with several consecutive periods of field time. These trends were found for all positional categories. Intensity increased substantially in the final 5 min of the first half for team profiles. Activity levels were substantially lower in the 5 min after a player's most intense period and were partly restored in the subsequent 5-min period. Possible explanations for the observed declines in activity profiles for the team and individual players include fatigue, situational factors, and pacing. However, underlying mechanisms were not accounted for, and these assumptions are therefore based on previous team-sport studies.

Risk factors for overuse shoulder injuries in a mixed-sex cohort of 329 elite handball players: previous findings could not be confirmed.

PubMed

Andersson, Stig Haugsboe; Bahr, Roald; Clarsen, Benjamin; Myklebust, Grethe

2017-08-07

Shoulder injuries are common among handball players and predominantly characterised by overuse characteristics. Reduced total glenohumeral rotation, external rotation weakness and scapular dyskinesis have been identified as risk factors among elite male handball players. To assess whether previously identified risk factors are associated with overuse shoulder injuries in a large cohort of elite male and female handball players. 329 players (168 male, 161 female) from the two upper divisions in Norway were included and tested prior to the 2014-2015 season. Measures included glenohumeral internal and external rotation range of motion, isometric internal and external rotation strength, and assessment of scapular dyskinesis. Players were followed prospectively for one competitive season, with prevalence and severity of shoulder problems registered monthly using the Oslo Sports Trauma Research Center Overuse Injury Questionnaire. A severity score based on players' questionnaire responses was used as the outcome measure in multivariable logistic regression to investigate associations between candidate risk factors and overuse shoulder injury. No significant associations were found between total rotation (OR 1.05 per 5° change, 95% CI 0.98 to 1.13), external rotation strength (OR 1.05 per 10 N change, 95% CI 0.92 to 1.20) or obvious scapular dyskinesis (OR 1.23, 95% CI 0.25 to 5.99) and overuse shoulder injury. A significant positive association was found between greater internal rotation (OR 1.16 per 5° change, 95% CI 1.00 to 1.34) and overuse shoulder injury. None of the previously identified risk factors were associated with overuse shoulder injuries in a mixed-sex cohort of elite handball players. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Intermediate experimental vehicle, ESA program aerodynamics-aerothermodynamics key technologies for spacecraft design and successful flight

NASA Astrophysics Data System (ADS)

Dutheil, Sylvain; Pibarot, Julien; Tran, Dac; Vallee, Jean-Jacques; Tribot, Jean-Pierre

2016-07-01

With the aim of placing Europe among the world's space players in the strategic area of atmospheric re-entry, several studies on experimental vehicle concepts and improvements of critical re-entry technologies have paved the way for the flight of an experimental space craft. The successful flight of the Intermediate eXperimental Vehicle (IXV), under ESA's Future Launchers Preparatory Programme (FLPP), is definitively a significant step forward from the Atmospheric Reentry Demonstrator flight (1998), establishing Europe as a key player in this field. The IXV project objectives were the design, development, manufacture and ground and flight verification of an autonomous European lifting and aerodynamically controlled reentry system, which is highly flexible and maneuverable. The paper presents, the role of aerodynamics aerothermodynamics as part of the key technologies for designing an atmospheric re-entry spacecraft and securing a successful flight.

Strength Asymmetry of the Shoulders in Elite Volleyball Players

PubMed Central

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

2014-01-01

Context: 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. Objective: 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. Design: Descriptive laboratory study. Patients or Other Participants: A sample of 183 volleyball players (99 men, 84 women). Main Outcome Measure(s): 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. Results: 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. Conclusions: 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

Between-game variation of physical soccer performance measures in highly trained youth soccer players.

PubMed

Doncaster, Greg; Unnithan, Viswanath

2017-07-12

To assess the between-game variation in measures of physical performance during 11 v 11 soccer match-play, over a short period of time, in highly trained youth soccer players. A single cohort observational study design was employed. Physical match performance data were collected from 17 male, highly trained youth soccer players (age: 13.3 ± 0.4 y) over three, 2 x 20min, 11 v 11 matches. Using 10 Hz GPS, the variables selected for analyses were total distance (TD), high-speed running (HSR), very high-speed running (VHSR), number of high-speed running efforts (HSReff) and number of very high-speed running efforts (VHSReff). Match data was also separated into cumulative 5 min epochs, to identify the peak 5 min epoch and the mean of the cumulative 5 min epochs for each match. Variability was quantified using the coefficient of variation (CV), Standard error of measurement (SEM) and intra-class correlation coefficient (ICC). Between- and within-player smallest worthwhile changes (SWC) were also calculated for each variable to aid in the interpretation of the data. Analysis of the variance between games reported a low CV for TD (3.8%) but larger CVs for HSR (33.3%), HSReff (35.4%) and VHSR and VHSReff (59.6 and 57.4 %, respectively). Analysis of 5 min epochs (peak and average) found an increase in the CVs beyond that of the values reported for the whole match. Between-player SWC in high intensity physical performance data ranged from 24.7 - 42.4 %, whereas within-player SWC ranged from 1.2 - 79.9%. The between-game variability of high and very high intensity activities in youth soccer players, across three soccer matches over a short period of time (2 weeks), is relatively 'large' and specific to the individual, thus highlighting the need for caution when interpreting physical performance data between games and players.

Perceived Musculoskeletal Discomfort among Elementary, Middle, and High School String Players

ERIC Educational Resources Information Center

Russell, Joshua A.; Benedetto, Rachel L.

2014-01-01

The purposes of this study were to identify the body regions where young string players report experiencing musculoskeletal discomfort and explore factors that may impact their perceived discomfort. A purposive yet nonprobability sample of elementary (n = 101), middle school (n = 97), and high school (n = 159) students participated in the study by…

Anthropometric and physiological profiles of sepak takraw players

PubMed Central

Jawis, M; Singh, R; Singh, H; Yassin, M; Khanna, G

2005-01-01

Objectives: Anthropometric and physiological profiles of national sepak takraw players were determined. Methods: Thirty nine players, specialising in the three playing positions (tekong/server, feeder, and killer/spiker) were divided into three age categories of under 15 (U15), under 18 (U18), and under 23 (U23) years of age. Height, weight, percent body fat (%bf), maximum oxygen consumption (Vo2max), range of motion (ROM), back and leg strength, and heart rate, for the estimation of oxygen consumption during matches, were recorded. Statistical analysis was performed using one way ANOVA for independent measurements and data are presented as mean±standard deviation. Results: The U23 players were significantly taller and heavier with significantly better ROM of the neck, trunk, and ankle joints and back and leg strength than the U15 players. No significant difference was found in %bf between the three age categories. Mean maximum heart rate during exercise was significantly higher in the U15 group when compared to the U18 and U23 groups (p<0.05). Mean Vo2max was similar between the three groups. Estimated oxygen consumption during matches was 69.1%, 68.5%, and 56.4% of Vo2max in the killer, tekong, and the feeder groups, respectively. Conclusions: The mean height, body weight, and cardiopulmonary capacities of the players were within the Malaysian population norms, but were somewhat lower than those of players of other court games from other countries. %bf was also lower in these players. This study provides the much needed anthropometric and physiological data of sepak takraw players for further development of this sport. PMID:16244191

Hip Strength as an Intrinsic Risk Factor for Lateral Ankle Sprains in Youth Soccer Players: A 3-Season Prospective Study.

PubMed

De Ridder, Roel; Witvrouw, Erik; Dolphens, Mieke; Roosen, Philip; Van Ginckel, Ans

2017-02-01

Numerous epidemiological studies have emphasized the burden of lateral ankle sprains in youth soccer players. However, no prospective study has identified intrinsic physical and modifiable risk factors for these injuries in this particular population. Although injury prevention programs in soccer incorporate proximal hip and core stability exercises, it is striking that the relationship between impaired proximal hip function and ankle sprains has not yet been prospectively investigated in youth soccer players. This prospective study aimed to examine whether hip muscle strength is a risk factor for sustaining a lateral ankle sprain in youth soccer players. We hypothesized that decreased hip muscle strength would predispose youth soccer players to an increased risk of lateral ankle sprains. Case-control study; Level of evidence, 3. This study included a total of 133 male youth soccer players (age divisions U11-U17) for analysis. At the beginning of the season, anthropometric characteristics were collected and hip muscle strength was assessed using a handheld dynamometer. Injury registration was performed by the team medical staff during 3 consecutive seasons. A principal-component, multivariate Cox regression analysis was performed to identify potential risk factors for sustaining a lateral ankle sprain. Twelve participants (18% of all reported injuries) sustained a lateral ankle sprain (0.36 per 1000 athletic-exposure hours). After adjustment for body size dependencies and other hip muscle forces, an increase in hip muscle extension force was associated with a significant decrease in the hazard of the injury (hazard ratio, 0.3; 95% confidence interval, 0.1-0.9; P = .028). No other study variable could be identified as a risk factor for lateral ankle sprains. Reduced hip extension muscle strength is an independent risk factor for lateral ankle sprains in male youth soccer players. Other hip muscle strength outcomes were not identified as risk factors. Replication in

Incidence of tinnitus in mp3 player users.

PubMed

Figueiredo, Ricardo Rodrigues; Azevedo, Andreia Aparecida de; Oliveira, Patrícia Mello de; Amorim, Sandro Pereira Vasconcellos; Rios, Artur Guedes; Baptista, Vanderlei

2011-06-01

Exposure to loud noise is one of the main causes of tinnitus. To analyze the incidence of tinnitus in mp3 player users and non-users. One hundred subjects aged from 15 to 30 years were enrolled, 54 of them were regular mp3 player users and 46 were not. Patients with continuous tinnitus for at least 6 months completed the Tinnitus Handicap Inventory (THI) and were tested with high frequency audiometry and transient-evoked otoacoustic emissions (TAOE). A cross-sectional cohort study. The incidence of tinnitus in non-users was about 8 %; in mp3 player users it was about 28 %, a statistically significant difference. Hearing thresholds at 8 kHz were significantly higher in tinnitus patients that used mp3 portable players.TAOE were reduced at 2 kHz in the users group. No statistically significant difference was found in the THI scores between the two groups. Tinnitus was more frequent in teenagers and young adults who regularly listen to mp3 music in players. Moreover, the incidence of tinnitus among mp3 player users was associated with higher hearing thresholds at 8 kHz and lower TOAE at 2 kHz.

Interaction with the game and motivation among players of massively multiplayer online role-playing games.

PubMed

Fuster, Héctor; Carbonell, Xavier; Chamarro, Andrés; Oberst, Ursula

2013-01-01

Knowledge about users interacting with Massively Multiplayer Online Role-Playing Games (MMORPG) is fundamental in order to prevent their potential negative effects on behavior. For this reason, the present study analyzed the relationship between styles of play and motivations. An online questionnaire asking for socio-demographic details, playing style, characteristics of the game played and motivations for playing, was answered by 430 Spanish-speaking MMORPG players (45.1% males). The identified profile for players, far away from the stereotype of an adolescent, consisted in a person who mainly plays on PvP (Player versus Player) servers, choosing the type of game according to his experience. Regarding motivations, they were interested in relating with other players through the game (Socialization), in discovering the game's possibilities and development of its adventures (Exploration), to a lesser extent in leadership and prestige (Achievement) and, lastly, identification with an avatar and escape from reality (Dissociation). Although part of the reason for playing was escapism and/or stress relief, the main motivation had a social nature. We conclude that MMORPG offer an attractive environment for a broad spectrum of people, and we have not been able to confirm the stereotype of a loner avoiding reality, taking refuge in games.

Female Chess Players Outperform Expectations When Playing Men.

PubMed

Stafford, Tom

2018-03-01

Stereotype threat has been offered as a potential explanation of differential performance between men and women in some cognitive domains. Questions remain about the reliability and generality of the phenomenon. Previous studies have found that stereotype threat is activated in female chess players when they are matched against male players. I used data from over 5.5 million games of international tournament chess and found no evidence of a stereotype-threat effect. In fact, female players outperform expectations when playing men. Further analysis showed no influence of degree of challenge, player age, nor prevalence of female role models in national chess leagues on differences in performance when women play men versus when they play women. Though this analysis contradicts one specific mechanism of influence of gender stereotypes, the persistent differences between male and female players suggest that systematic factors do exist and remain to be uncovered.

Tournament Structure and Success of Players Based on Location in Men’s Professional Tennis

PubMed Central

Panjan, Andrej; Reid, Machar; Crespo, Miguel; Sarabon, Nejc

2013-01-01

This article discusses the relationship between success of professional male tennis players according to the country and world region from which they originate and the professional tournament structure in men’s tennis in that world region and country. The success of a country or world region was defined by the number of players in the top 300 ATP rankings and was calculated for seven time periods between 1975 and 2008. The results showed the correlations between the total number of top 300 ranked players, the total number of tournaments, and the annual tournament prize money of the specific country. The correlations were nearly perfect in the 1975-1990 period (r = 0.93-0.95; p < 0.01) but only high in the 2005-2008 period (r = 0.60-0.64; p < 0.01), suggesting that the association between the number of top 300 ranked tennis players and professional tournaments, while still significant, is in decline. These data should inform the policy and investment decisions of regional and national federations, particularly as they relate to domestic professional tennis tournament structures and to explore opportunities to include professional tournaments of neighbour countries in their player’s development programs. Key Points This paper observes relation changes between the total number of players, total number of ATP tournaments and total annual prize money in particular continents from 1975 to 2008. The correlation between the tennis success, total number of tournaments and total annual prize money in tournaments was highest from 1975 to 1989 and was gradually decreasing from 1990 to 2008. The leading tennis countries organise over 20 ATP tournaments and entry professional tournaments per year. Tennis less developed countries very often is using the competition systems of the most successful tennis countries. Indications are that tennis will continue to become increasingly global and that this trend may be unlikely to reverse. PMID:24149816

Effects of knowing the task duration on players' pacing patterns during soccer small-sided games.

PubMed

Ferraz, Ricardo; Gonçalves, Bruno; Van Den Tillaar, Roland; Jiménez Sáiz, Sergio; Sampaio, Jaime; Marques, Mário C

2018-01-01

The aim of this study was to identify the influence of prior knowledge of exercise duration on players' pacing patterns during soccer small-sided games. Twenty semi-professional male soccer players participated in this study. In the first game scenario, players were not informed how long they would be required to play the small-sided game and the activity was terminated after 20 min (Unknown Condition). In the second game scenario, players were told that they would play the small-sided game for 10 min, but immediately after completing the 10-min game, they were asked to complete another 10 min (Partially Condition). In the third game scenario, players were instructed that they would play the small-sided game for 20 min and then they completed the 20-min game (Known Condition). The results presented a tendency of higher values in all performance variables in the [0'-10'] min compared with the [10'-20'] min. As the players' previous knowledge about the tasks duration increased, the performance between two moments tended to be similar. Considering the entire 20-min game duration, the Partially Condition of the exercise was the most demanding condition. In conclusion, the knowledge of shorter durations of the exercise seems to lead to an increase of exercise duration demand, and longer exercise durations possibly tend to decrease differences between full knowledge and not knowing the exercise duration.

Comparison of Ball-And-Racket Impact Force in Two-Handed Backhand Stroke Stances for Different-Skill-Level Tennis Players.

PubMed

Lo, Kuo-Cheng; Hsieh, Yung-Chun

2016-06-01

This study compared the kinetic roles of the upper extremities in racket impact force generation between the open stance (OS) and square stance (SS) for tennis players with different skill levels in two-handed backhand strokes. Twelve male tennis players were divided into an advanced group (AG) (L3-L2 skill level) and intermediate group (IG) (L7-L6 skill level), and their data were used in a three-dimensional kinetic analysis. Their motions were captured using 21 reflective markers attached to anatomic landmarks for two-handed backhand stroke motion data collection. During the acceleration phase, significant differences were not observed between both stances, but they were observed between the groups with different skill levels for the force of the upper extremities (p = 0.027). The joint forces were significantly lower in the AG than in the IG. Players performing the SS had significantly larger pronation and supination of the wrist joint moment than those in the OS (p = 0.032) during the acceleration phase, irrespective of the playing level. Higher internal rotation moment after impact was observed at each joint, particularly among young intermediate tennis players, regardless of their stance. The AG demonstrated a higher joint force and moment at every joint compared with the IG at impact. Moreover, the AG demonstrated superior stroke efficiency and effectively reduced joint moment after impact and sports injury. Key pointsAdvanced players, regardless of open stance or square stance, have larger joint force and moment at each joint before ball impact resulting in better stroke efficiency and reduced chance of injury.Intermediate players, regardless of stance, have higher internal rotation moment at each joint instead of larger joint force as compared to advanced players before ball impact. The higher internal rotation moment will induce higher joint impact force which makes the player injury-prone.Young intermediate tennis players may want to avoid excessive

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

PubMed

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.

Cortical thinning in former professional soccer players.

PubMed

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.

Changes in Adductor Strength After Competition in Academy Rugby Union Players.

PubMed

Roe, Gregory A B; Phibbs, Padraic J; Till, Kevin; Jones, Ben L; Read, Dale B; Weakley, Jonathon J; Darrall-Jones, Joshua D

2016-02-01

This study determined the magnitude of change in adductor strength after a competitive match in academy rugby union players and examined the relationship between locomotive demands of match-play and changes in postmatch adductor strength. A within-subject repeated measures design was used. Fourteen academy rugby union players (age, 17.4 ± 0.8 years; height, 182.7 ± 7.6 cm; body mass, 86.2 ± 11.6 kg) participated in the study. Each player performed 3 maximal adductor squeezes at 45° of hip flexion before and immediately, 24, 48, and 72 hours postmatch. Global positioning system was used to assess locomotive demands of match-play. Trivial decreases in adductor squeeze scores occurred immediately (-1.3 ± 2.5%; effect size [ES] = -0.11 ± 0.21; likely, 74%) and 24 hours after match (-0.7 ± 3%; ES = -0.06 ± 0.25; likely, 78%), whereas a small but substantial increase occurred at 48 hours (3.8 ± 1.9%; ES = 0.32 ± 0.16; likely, 89%) before reducing to trivial at 72 hours after match (3.1 ± 2.2%; ES = 0.26 ± 0.18; possibly, 72%). Large individual variation in adductor strength was observed at all time points. The relationship between changes in adductor strength and distance covered at sprinting speed (VO2max ≥ 81%) was large immediately postmatch (p = 0.056, r = -0.521), moderate at 24 hours (p = 0.094, r = -0.465), and very large at 48 hours postmatch (p = 0.005, r = -0.707). Players who cover greater distances sprinting may suffer greater adductor fatigue in the first 48 hours after competition. The assessment of adductor strength using the adductor squeeze test should be considered postmatch to identify players who may require additional rest before returning to field-based training.

Vitamin D receptor gene polymorphisms and musculoskeletal injuries in professional football players

PubMed Central

MASSIDDA, MYOSOTIS; CORRIAS, LAURA; BACHIS, VALERIA; CUGIA, PAOLO; PIRAS, FRANCESCO; SCORCU, MARCO; CALÒ, CARLA M.

2015-01-01

The aim of the present study was to investigate the association between vitamin D receptor (VDR) gene polymorphisms and musculoskeletal injury (MI) in elite football players. In total, 54 male professional football players were recruited from an official Italian professional championship team between 2009 and 2013. The cohort was genotyped for the ApaI, BsmI and FokI polymorphisms and MI data were collected over four football seasons. No significant differences were identified among the genotypes in the incidence rates or severity of MI (P=0.254). In addition, no significant associations were observed between VDR polymorphisms and MI phenotypes (P=0.460). However, the results of the casewise multiple regression analysis indicated that the ApaI genotypes accounted for 18% of injury severity (P=0.002). Therefore, while the BsmI and FokI polymorphisms did not appear to be associated with the severity or incidence of MI, the ApaI genotypes may have influenced the severity of muscle injury in top-level football players. PMID:26161149

The effect of low back pain on trunk muscle size/function and hip strength in elite football (soccer) players.

PubMed

Hides, Julie A; Oostenbroek, Tim; Franettovich Smith, Melinda M; Mendis, M Dilani

2016-12-01

Low back pain (LBP) is a common problem in football (soccer) players. The effect of LBP on the trunk and hip muscles in this group is unknown. The relationship between LBP and trunk muscle size and function in football players across the preseason was examined. A secondary aim was to assess hip muscle strength. Twenty-five elite soccer players participated in the study, with assessments conducted on 23 players at both the start and end of the preseason. LBP was assessed with questionnaires and ultrasound imaging was used to assess size and function of trunk muscles at the start and end of preseason. Dynamometry was used to assess hip muscle strength at the start of the preseason. At the start of the preseason, 28% of players reported the presence of LBP and this was associated with reduced size of the multifidus, increased contraction of the transversus abdominis and multifidus muscles. LBP decreased across the preseason, and size of the multifidus muscle improved over the preseason. Ability to contract the abdominal and multifidus muscles did not alter across the preseason. Asymmetry in hip adductor and abductor muscle strength was found between players with and without LBP. Identifying modifiable factors in players with LBP may allow development of more targeted preseason rehabilitation programmes.

Upper extremity sensorimotor control among collegiate football players.

PubMed

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 < 0.05). The 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.

Aseptic meningitis outbreak associated with echovirus 30 among high school football players--Los Angeles County, California, 2014.

PubMed

Croker, Curtis; Civen, Rachel; Keough, Kathleen; Ngo, Van; Marutani, Amy; Schwartz, Benjamin

2015-01-02

On August 4, 2014, the Acute Communicable Disease Control Program of the Los Angeles County Department of Public Health received a report of three aseptic meningitis cases among football players at a county high school. An investigation was conducted to determine the extent of the outbreak, identify potential exposures, and recommend control measures. An outbreak-associated aseptic meningitis case was defined as an illness of any team or family member with onset during July 28-August 11 with 1) cerebrospinal fluid pleocytosis and negative bacterial culture or 2) an emergency department visit with headache, fever, and stiff neck. Ten cases were identified; nine in males, and one in a female; patient ages ranged from 13 to 17 years. All the patients sought care at an emergency department, and five were hospitalized, resulting in 12 total hospital days. All 10 patients have recovered. Eight patients were football players, and two were siblings of football players. The most affected subgroup was the junior varsity football team, with seven cases out of 57 players (attack rate = 12.3%); the relative risk for aseptic meningitis was higher among players who were linemen than among those who were not linemen (relative risk = 5.4 [p = 0.03]). Of the 10 patients, eight tested positive by polymerase chain reaction for enterovirus, and two were not tested. Echovirus testing was performed at the California Viral and Rickettsial Disease Laboratory. Of the eight specimens testing positive for enterovirus, seven tested positive for echovirus 30, and one specimen could not be typed because of insufficient quantity.

BDNF - A key player in cardiovascular system.

PubMed

Pius-Sadowska, Ewa; Machaliński, Bogusław

2017-09-01

Neurotrophins (NTs) were first identified as target-derived survival factors for neurons of the central and peripheral nervous system (PNS). They are known to control neural cell fate, development and function. Independently of their neuronal properties, NTs exert unique cardiovascular activity. The heart is innervated by sensory, sympathetic and parasympathetic neurons, which require NTs during early development and in the establishment of mature properties, contributing to the maintenance of cardiovascular homeostasis. The identification of molecular mechanisms regulated by NTs and involved in the crosstalk between cardiac sympathetic nerves, cardiomyocytes, cardiac fibroblasts, and vascular cells, has a fundamental importance in both normal heart function and disease. The article aims to review the recent data on the effects of Brain-Derived Neurotrophic Factor (BDNF) on various cardiovascular neuronal and non-neuronal functions such as the modulation of synaptic properties of autonomic neurons, axonal outgrowth and sprouting, formation of the vascular and neural networks, smooth muscle migration, and control of endothelial cell survival and cardiomyocytes. Understanding these mechanisms may be crucial for developing novel therapeutic strategies, including stem cell-based therapies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Beyond the Player: A User-Centered Approach to Analyzing Digital Games and Players Using Actor-Network Theory

ERIC Educational Resources Information Center

Hung, Aaron Chia Yuan

2016-01-01

The paper uses actor-network theory (ANT) to analyze the sociotechnical networks of three groups of adolescents who played online games in different physical and social contexts. These include: an internet café, which allowed the players to be co-present; a personal laptop, which gave the player more control over how he played; and at home through…

Exercise Intensity and Technical Demands of Small-Sided Soccer Games for Under-12 and Under-14 Players: Effect of Area per Player.

PubMed

Martone, Domenico; Giacobbe, Moreno; Capobianco, Adriano; Imperlini, Esther; Mancini, Annamaria; Capasso, Mario; Buono, Pasqualina; Orrù, Stefania

2017-06-01

The aim of this study was to evaluate the effects of 6 different areas per player (AP) on exercise intensity (EI) measured during small-sided games (SSGs) and expressed as percentage of maximal heart rate (%MHR) and technical actions (TAs) involvement with the ball, crosses, headers, tackles, shots on goal, dribbling, passing, and target passing-in U-12 and U-14 soccer players during SSGs. Seventeen male U-12 soccer players (age 10.0 ± 0.5 years, body mass 39.3 ± 5.3 kg, and height 143.8 ± 4.6 cm) and 16 male U-14 soccer players (age 13.2 ± 0.3 years, body mass 46.6 ± 11.9 kg, and height 154.8 ± 8.5 cm) performed SSGs with different AP: 40, 50, 66.7, 90, 112.5, and 150 m. Our results indicate that at larger AP, the U-12 group's mean EI values were significantly higher than those at smaller AP (p ≤ 0.05); in addition, intergroup comparison showed that EI was higher in U-12 than that in U-14 players when AP of 112.5 and 150 m were considered (p ≤ 0.05). Technical action analysis evidenced that moving from smaller to larger AP, U-14 players adapted better to AP changes. In conclusion, these results suggest that AP influences differently EI and TAs in U-12 and U-14 players. Our results could be taken into account by conditioning coaches to better tailor the physiological and technical training in young players through the modulation of AP.

Exploring design features for enhancing players' challenge in strategy games.

PubMed

Hsu, Shang Hwa; Wen, Ming-Hui; Wu, Muh-Cherng

2007-06-01

This paper examines how to make a player feel more challenged in a strategic computer game. It is hypothesized that information availability and resource advantage affect play difficulty, which in turn affects the challenge experienced. The difficulty of play can be defined in terms of the mental workload that players experience and the physical effort that players exert. Forty-five male college and graduate students participated in a 3 x 3 (information availability x resource advantage) between-subjects factorial design experiment. This experiment measured player mental workload, physical effort, and challenge. The results indicate that information availability affects player mental workload, and resource advantage affects levels of player physical effort, respectively. Moreover, the relationship between mental workload and challenge was found to be an inverted U-shaped curve; in other words, too much or too little mental workload may decrease player challenge. The relationship between physical effort and challenge exhibited similar characteristics.

Neuroimaging of cognitive dysfunction and depression in aging retired National Football League players: a cross-sectional study.

PubMed

Hart, John; Kraut, Michael A; Womack, Kyle B; Strain, Jeremy; Didehbani, Nyaz; Bartz, Elizabeth; Conover, Heather; Mansinghani, Sethesh; Lu, Hanzhang; Cullum, C Munro

2013-03-01

OBJECTIVES To assess cognitive impairment and depression in aging former professional football (National Football League [NFL]) players and to identify neuroimaging correlates of these dysfunctions. DESIGN We compared former NFL players with cognitive impairment and depression, cognitively normal retired players who were not depressed, and matched healthy control subjects. SETTING Research center in the North Texas region of the United States. PATIENTS Cross-sectional sample of former NFL players with and without a history of concussion recruited from the North Texas region and age-, education-, and IQ-matched controls. Thirty-four retired NFL players (mean age, 61.8 years) underwent neurological and neuropsychological assessment. A subset of 26 players also underwent detailed neuroimaging; imaging data in this subset were compared with imaging data acquired in 26 healthy matched controls. MAIN OUTCOME MEASURES Neuropsychological measures, clinical diagnoses of depression, neuroimaging mea-sures of white matter pathology, and a measure of cerebral blood flow. RESULTS Of the 34 former NFL players, 20 were cognitively normal. Four were diagnosed as having a fixed cognitive deficit; 8, mild cognitive impairment; 2, dementia; and 8, depression. Of the subgroup in whom neuroimaging data were acquired, cognitively impaired participants showed the greatest deficits on tests of naming, word finding, and visual/verbal episodic memory. We found significant differences in white matter abnormalities in cognitively impaired and depressed retired players compared with their respective controls. Regional blood flow differences in the cognitively impaired group (left temporal pole, inferior parietal lobule, and superior temporal gyrus) corresponded to regions associated with impaired neurocognitive performance (problems with memory, naming, and word finding). CONCLUSIONS Cognitive deficits and depression appear to be more common in aging former NFL players compared with healthy

How should "hot" players in basketball be defended? The use of fast-and-frugal heuristics by basketball coaches and players in response to streakiness.

PubMed

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.

Approximate N-Player Nonzero-Sum Game Solution for an Uncertain Continuous Nonlinear System.

PubMed

Johnson, Marcus; Kamalapurkar, Rushikesh; Bhasin, Shubhendu; Dixon, Warren E

2015-08-01

An approximate online equilibrium solution is developed for an N -player nonzero-sum game subject to continuous-time nonlinear unknown dynamics and an infinite horizon quadratic cost. A novel actor-critic-identifier structure is used, wherein a robust dynamic neural network is used to asymptotically identify the uncertain system with additive disturbances, and a set of critic and actor NNs are used to approximate the value functions and equilibrium policies, respectively. The weight update laws for the actor neural networks (NNs) are generated using a gradient-descent method, and the critic NNs are generated by least square regression, which are both based on the modified Bellman error that is independent of the system dynamics. A Lyapunov-based stability analysis shows that uniformly ultimately bounded tracking is achieved, and a convergence analysis demonstrates that the approximate control policies converge to a neighborhood of the optimal solutions. The actor, critic, and identifier structures are implemented in real time continuously and simultaneously. Simulations on two and three player games illustrate the performance of the developed method.

Soccer player recognition by pixel classification in a hybrid color space

NASA Astrophysics Data System (ADS)

Vandenbroucke, Nicolas; Macaire, Ludovic; Postaire, Jack-Gerard

1997-08-01

Soccer is a very popular sport all over the world, Coaches and sport commentators need accurate information about soccer games, especially about the players behavior. These information can be gathered by inspectors who watch the soccer match and report manually the actions of the players involved in the principal phases of the game. Generally, these inspectors focus their attention on the few players standing near the ball and don't report about the motion of all the other players. So it seems desirable to design a system which automatically tracks all the players in real- time. That's why we propose to automatically track each player through the successive color images of the sequences acquired by a fixed color camera. Each player which is present in the image, is modelized by an active contour model or snake. When, during the soccer match, a player is hidden by another, the snakes which track these two players merge. So, it becomes impossible to track the players, except if the snakes are interactively re-initialized. Fortunately, in most cases, the two players don't belong to the same team. That is why we present an algorithm which recognizes the teams of the players by pixels representing the soccer ground which must be withdrawn before considering the players themselves. To eliminate these pixels, the color characteristics of the ground are determined interactively. In a second step, dealing with windows containing only one player of one team, the color features which yield the best discrimination between the two teams are selected. Thanks to these color features, the pixels associated to the players of the two teams form two separated clusters into a color space. In fact, there are many color representation systems and it's interesting to evaluate the features which provide the best separation between the two classes of pixels according to the players soccer suit. Finally, the classification process for image segmentation is based on the three most

[Prevalence of genital anomalies in young football players].

PubMed

Mónaco, M; Verdugo, F; Bodell, M; Avendaño, E; Til, L; Drobnic, F

2015-01-01

The purpose of genital examination (GE) during the Pre-participation Physical Examination (PPE) is to identify the state of maturity, and rule out any genital pathology. To describe genital anomalies (GA) and estimate the awareness of GE in young football players. A descriptive, cross-sectional study was conducted in 280 elite football players from the results of PPE over two seasons. There was a detection rate of 5.4% GA, with varicocele being 3.2%, and of which only 13% were aware of their condition. Although this study shows a low incidence of genital abnormality in the study population, only 13% were aware of the GE prior to assessment. These findings demonstrate a low incidence of GA in this population. While GE is recommended during PPE, it is not a routine practice performed by family doctors or sports medicine specialists. This article attempts to raise awareness of the importance of GE in PPE as a preventive health strategy. Copyright © 2014 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

Macronutrient Intakes of Male Rugby Union Players: A Review.

PubMed

Black, Katherine E; Black, Alistair D; Baker, Dane F

2018-02-27

Rugby is a worldwide intermittent team sport, players tend to be heavier than the majority of similar team sport athletes on whom the dietary guidelines have been developed. Therefore, the aim of the current review was to describe the intakes of rugby union players. Article databases were searched up to February 2017 and were included if they were published in English and reporting dietary intakes of male rugby union players. Of the research articles found energy intakes were lower than four of the five studies which reported intakes and expenditure, which would suggest the players were losing weight which is somewhat supported by the decreases in skinfolds seen during pre-season. However, it should also be noted that there are errors in both the measurement of energy intakes and expenditure. Carbohydrate intakes ranged from 2.6 to 6.5 g·kg -1 ·d -1 , which is lower than the current relative to body mass recommendations however, this would not be classed as a low carbohydrate diet. The consistently low intakes of carbohydrate suggest that these intake levels maybe sufficient for performance, given the players greater body mass or there are errors in the measurements. However, there is currently no evidence for the carbohydrate needs of rugby union players in terms of performance. The lower intakes than expenditure would suggest the players were losing weight. Previous research in rugby union players lose body fat during pre-season training.

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

PubMed

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.

Menstrual cycle disorders in female volleyball players.

PubMed

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.

Effect of Concussion on Performance of National Football League Players.

PubMed

Reams, Nicole; Hayward, Rodney A; Kutcher, Jeffrey S; Burke, James F

2017-09-01

Lingering neurologic injury after concussion may expose athletes to increased risk if return to play is premature. The authors explored whether on-field performance after concussion is a marker of lingering neurologic injury. Retrospective cohort study on 1882 skill-position players who played in the National Football League (NFL) during 2007-2010. Players with concussion based on the weekly injury report were compared with players with other head and neck injuries (controls) on measures of on-field performance using Football Outsiders' calculation of defense-adjusted yards above replacement (DYAR), a measure of a player's contribution controlling for game context. Changes in performance, relative to a player's baseline level of performance, were estimated before and after injury using fixed-effects models. The study included 140 concussed players and 57 controls. Players with concussion performed no better or worse than their baseline on return to play. However, a decline in DYAR relative to their prior performance was noted 2 wk and 1 wk before appearing on the injury report. Concussed players performed slightly better than controls in situations where they returned to play the same week as appearing on the injury report. On return, concussed NFL players performed at their baseline level of performance, suggesting that players have recovered from concussion. Decline in performance noted 2 wk and 1 wk before appearing on the injury report may suggest that concussion diagnosis was delayed or that concussion can be a multihit phenomenon. Athletic performance may be a novel tool for assessing concussion injury and recovery.

Position specific morphological characteristics of top-level male handball players.

PubMed

Srhoj, V; Marinović, M; Rogulj, N

2002-06-01

With the aim of determining the common morphological features of senior male handball players and of analyzing their specificities i.e. the probable variation between the four playing positions (back court players, wings, pivots, goalkeepers), 25 anthropometric measures were applied to the sample of 49 players, members of three top-quality handball teams. The basic descriptive parameters were calculated and then an analysis of variance and a cluster analysis were performed. A mesomorphic, athletic body- type was obtained with a marked longitudinal skeleton dimensionality, but also with a balanced ratio between the skeletal system and muscle mass and with low values of subcutaneous fat tissue. Back court players and goalkeepers are superior in terms of outstanding skeletal dimensions and circumferences. Line players, i.e. wings and pivots, have somewhat lower longitudinal measures, whereas pronounced voluminosity and a slightly higher fat tissue value differentiate pivots from players in other positions. Cluster analysis revealed a greater homogeneity in the morphological profiles of the samples of line players (wings and pivots) than in the profiles of backs or goalkeepers. The obtained position-related differences in morphological characteristics of players suggest that the experienced players from the sample were earlier successfully subjected to the selection process and oriented to a particular playing position because of the observed correspondence between their body-type and specific kinesiological demands of the position in question. Therefore, in top-quality team-handball it would be recommendable to select players whose morphological profiles are as compatible as possible with positional specificities in the demand for the game.

Time-Loss and Non–Time-Loss Injuries in Youth Football Players

PubMed Central

Dompier, Thomas P; Powell, John W; Barron, Mary J; Moore, Marguerite T

2007-01-01

Context: Estimates suggest that more than 5.5 million youths play football annually, and 28% of youth football players (age range = 5 to 14 years) are injured each year, resulting in more than 187 000 emergency room visits. Objective: To analyze time-loss (TL) and non–time-loss (NTL) injury patterns across age groups in youth football players. Design: Two-year observational cohort. Setting: Two midwestern communities, including players from the fourth through eighth grades and between the ages of 9 and 14 years. Patients or Other Participants: A total of 779 players participated, including 296 in grades 4 and 5; 203 in grade 6; 188 in grade 7; and 92 in grade 8. (Players in the fourth and fifth grades participated on the same teams, so we considered them as a single group.) Main Outcome Measure(s): Injury frequencies and exposures were collected by certified athletic trainers present at each practice and game and used to calculate injury rates with 95% confidence intervals (CIs) for both TL and NTL injuries across age groups. Results: A total of 474 injuries and 26 565 exposures were identified. Injuries were reported by 36.5% of the players, with 14.4% reporting more than 1 injury in a season. The overall injury rate per 1000 athlete-exposures (A-Es) was 17.8 (95% CI = 16.3, 19.5). The injury rate increased with each succeeding grade from 14.3 per 1000 A-Es (95% CI = 12.1, 16.9) in grades 4 and 5 to 21.7 per 1000 A-Es (95% CI = 17.2, 27.3) in grade 8. A total of 58.6% of all injuries were NTL. Non–time-loss injuries accounted for 70.1% of the injuries reported by fourth and fifth graders, 55.1% by sixth graders, 64.0% by seventh graders, and 33.8% by eighth graders. The cumulative NTL injury rate was 10.5 per 1000 A-Es (95% CI = 9.3, 11.8), and the TL injury rate was 7.4 per 1000 A-Es (95% CI = 6.4, 8.5). Conclusions: Youth football players sustained more NTL injuries than TL injuries. We recommend that a first-aid–certified coach or league official be

Nutritional requirements of young soccer players.

PubMed

Bar-Or, O; Unnithan, V B

1994-01-01

The general dietary needs of the young soccer player appear to be similar to those of the adult soccer player. There are, however, several age- and maturation-related differences. Compared with adults, children's daily recommended protein intake (per kg body mass) is higher; during exercise, children's muscles rely more on fat than on carbohydrates, but it is not clear whether young soccer players need higher dietary fat; calculated per kg body mass, the metabolic demands of walking and running are considerably higher in children; and during dehydration, children's core temperature rises faster, which calls for stricter enforcement of hydration. To increase fluid palatability, drinks should be flavoured, according to the child's individual preference. The efficacy and safety of 'carbohydrate loading' have not been studied in children.

Elite Junior Australian Football Players Experience Significantly Different Loads Across Levels of Competition and Training Modes.

PubMed

Lathlean, Timothy J H; Gastin, Paul B; Newstead, Stuart; Finch, Caroline F

2018-07-01

Lathlean, TJH, Gastin, PB, Newstead, S, and Finch, CF. Elite junior Australian football players experience significantly different loads across levels of competition and training modes. J Strength Cond Res 32(7): 2031-2038, 2018-Well-developed physical qualities such as high jumping ability, running endurance, acceleration, and speed can help aspiring junior elite Australian football (AF) players transition to the Australian Football League competition. To do so, players need to experience sufficient load to enhance their physical resilience without increasing their risk of negative outcomes in terms of impaired wellness or injury. The aim of this study was to investigate the differences in load for different levels of competition and training modes across one competitive season. Elite junior AF players (n = 562, aged 17.7 ± 0.3, range: 16-18 years) were recruited from 9 teams across the under-18 state league competition in Victoria. All players recorded their training and match intensities according to the session rating of perceived exertion method. Training sessions were categorized according to skills, strength, conditioning, and other activities, whereas matches were identified according to level of competition. The loads in U18 state league matches (656.7 ± 210.9 au) were significantly higher (p = 0.027) than those in school matches (643.3 ± 260.9 au) and those in U18 representative matches (617.2 ± 175.4). Players, who undertook more than one match per week, experienced significantly less load in subsequent matches (p < 0.001). Furthermore, U18 state league training sessions carried the most load when compared with other training modes. This article highlights that different combinations of training and match involvement affect overall player load, which may predispose players to negative outcomes such as impaired wellness or increased injury risk.

Comparison of shock transmission and forearm electromyography between experienced and recreational tennis players during backhand strokes.

PubMed

Wei, Shun-Hwa; Chiang, Jinn-Yen; Shiang, Tzyy-Yuang; Chang, Hsiao-Yun

2006-03-01

To test the hypothesis that recreational tennis players transmit more shock impact from the racket to the elbow joint than experienced tennis players during the backhand stroke. Also, to test whether recreational tennis players used higher electromyographic (EMG) activities in common wrist extensor and flexor around epicondylar region at follow-through phase. A repeated-measure, cross-sectional study. National College of Physical Education and Sports at Taipei, Taiwan. Twenty-four male tennis players with no abnormal forearm musculoskeletal injury participated in the study. According to performance level, subjects were categorized into 2 groups: experienced and recreational. Impact transmission and wrist extensor-flexor EMG for backhand acceleration, impact, and follow-through phases were recorded for each player. An independent t test with a significance level of 0.05 was used to examine mean differences of shock impact and EMG between the 2 test groups. One-way ANOVA associated with Tukey multiple comparisons was used to identify differences among different impact locations and EMG phases. Experienced athletes reduced the racket impact to the elbow joint by 89.2%, but recreational players reduced it by only 61.8%. The largest EMG differences were found in the follow-through phase (P<0.05). Experienced athletes showed that their extensor and flexor EMGs were at submaximal level for follow-through phase, whereas recreational players maintained their flexor and extensor EMGs at either supramaximal or maximal level. Our results support the hypothesis that recreational players transmit more shock impact from the racket to the elbow joint and use larger wrist flexor and extensor EMG activities at follow-through phase of the backhand stroke. Follow-through control is proposed as a critical factor for reduction of shock transmission. Clinicians or trainers should instruct beginners to quickly release their grip tightness after ball-to-racket impact to reduce shock impact

GuiaTreeKey, a multi-access electronic key to identify tree genera in French Guiana.

PubMed

Engel, Julien; Brousseau, Louise; Baraloto, Christopher

2016-01-01

The tropical rainforest of Amazonia is one of the most species-rich ecosystems on earth, with an estimated 16000 tree species. Due to this high diversity, botanical identification of trees in the Amazon is difficult, even to genus, often requiring the assistance of parataxonomists or taxonomic specialists. Advances in informatics tools offer a promising opportunity to develop user-friendly electronic keys to improve Amazonian tree identification. Here, we introduce an original multi-access electronic key for the identification of 389 tree genera occurring in French Guiana terra-firme forests, based on a set of 79 morphological characters related to vegetative, floral and fruit characters. Its purpose is to help Amazonian tree identification and to support the dissemination of botanical knowledge to non-specialists, including forest workers, students and researchers from other scientific disciplines. The electronic key is accessible with the free access software Xper ², and the database is publicly available on figshare: https://figshare.com/s/75d890b7d707e0ffc9bf (doi: 10.6084/m9.figshare.2682550).

Tracking of Ball and Players in Beach Volleyball Videos

PubMed Central

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

Linking performance decline to choking: players' perceptions in basketball.

PubMed

Fryer, Ashley Marie; Tenenbaum, Gershon; Chow, Graig M

2018-02-01

This study was aimed at examining how basketball players view unexpected performance errors in basketball, and under what conditions they perceive them as choking. Fifty-three basketball players were randomly assigned into 2 groups (game half) to evaluate the linkage between performance decline and choking as a function of game-time, score gap and game half. Within each group, players viewed 8 scenario clips, which featured a different player conducting an error, and subsequently rated the extent of performance decline, the instance of choking and the salience of various performance attributions regarding the error. The analysis revealed that choking was most salient in the 2nd half of the game, but an error was perceived as choking more saliently in the beginning of the 2nd half. This trend was also shown for players' perception of performance decline. Players' ratings of the attributions assigned to errors, however, revealed that during the end of the 2nd half, time pressure and lack of concentration were the causes of errors. Overall, the results provide evidence towards a conceptual framework linking performance decline to the perception of choking, and that errors conducted by players are perceived as choking when there is not a salient reason to suggest its occurrence.

Exploring Online Game Players' Flow Experiences and Positive Affect

ERIC Educational Resources Information Center

Chiang, Yu-Tzu; Lin, Sunny S. J.; Cheng, Chao-Yang; Liu, Eric Zhi-Feng

2011-01-01

The authors conducted two studies to explore online game players' flow experiences and positive affect. Our findings indicated that online game are capable of evoking flow experiences and positive affect, and games of violent or nonviolent type may not arouse players' aggression. The players could be placed into four flow conditions: flow,…

Fitness Profiles of Elite Adolescent Irish Rugby Union Players.

PubMed

Wood, Daniel J; Coughlan, Garrett F; Delahunt, Eamonn

2018-01-01

Wood, DJ, Coughlan, GF, and Delahunt, E. Fitness profiles of elite adolescent Irish rugby union players. J Strength Cond Res 32(1): 105-112, 2018-Rugby unions throughout the world are implementing player development models to prepare young players to meet the demands of professional rugby union. An example of this is the Irish Rugby Football Union Long Term Player Development model. The purpose of this study was to provide normative data relating to the physical fitness of elite adolescent Irish rugby union players and determine the differences in the physical capacities between players in the forward and back units as well as to provide descriptive data for the position categorizations within these units for this unique population. Players in the forward unit were significantly taller and heavier than players in the back unit (1.85 ± 0.06 m and 96.88 ± 9.00 kg vs. 1.79 ± 0.05 m and 81.97 ± 7.09 kg, respectively). Forwards (38.37 ± 4.00 cm) had a significantly lower countermovement jump height than backs (41.31 ± 4.44 cm). Forwards had a significantly lower triple hop for the distance score on their right (5.78 ± 0.52 m) and left (5.78 ± 0.55 m) legs compared with backs (6.26 ± 0.42 m and 6.33 ± 0.45 m, respectively). Forwards (1.85 ± 0.07 seconds) had a significantly higher 10-m sprint time than backs (1.77 ± 0.06 seconds). Furthermore, forwards (675.90 ± 82.46 m) had a significantly lower 150-m shuttle test score than backs (711.71 ± 27.46 m). The results of this study provide normative data for players who currently possess underage international potential and could be used by strength and conditioning coaches to guide the selection of players through talent identification processes.

Perceptions of football players regarding injury risk factors and prevention strategies

PubMed Central

Zech, Astrid; Wellmann, Kai

2017-01-01

Current approaches regarding injury prevention focus on the transfer of evidence into daily practice. One promising approach is to influence attitudes and beliefs of players. The objective of this study was to record player’s perceptions on injury prevention. A survey was performed among players of one German high-level football (soccer) club. 139 professional and youth players between age 13 and 35 years completed a standardized questionnaire (response rate = 98%). It included categories with (1) history of lower extremity injuries, (2) perceptions regarding risk factors and (3) regularly used prevention strategies. The majority of players (84.2%) had a previous injury. 47.5% of respondents believe that contact with other players is a risk factor, followed by fatigue (38.1%) and environmental factors (25.9%). The relevance of previous injuries as a risk factor is differently perceived between injured (25%) and uninjured players (0.0%). Nearly all players (91.5%) perform stretching to prevent injuries, followed by neuromuscular warm up exercises (54.0%). Taping is used by 40.2% of previously injured players and 13.6% of players without a history of injuries. In conclusion, the perception of risk factors and performed preventive strategies are inconsistent with scientific evidence. Future transfer strategies should incorporate the players beliefs and attitudes. PMID:28459845

Symptomatic Focal Knee Chondral Injuries in National Football League Combine Players Are Associated With Poorer Performance and Less Volume of Play.

PubMed

Provencher, Matthew T; Chahla, Jorge; Cinque, Mark E; Sanchez, George; Kennedy, Nicholas I; Haber, Daniel B; Tisosky, Ashley J; Beaulieu-Jones, Brendin R; Price, Mark D; Whalen, James M; Moatshe, Gilbert; LaPrade, Robert F

2018-03-01

To (1) describe the magnetic resonance imaging (MRI) characteristics of knee chondral injuries identified at the National Football League (NFL) Combine and (2) assess in-game performance of prospective NFL players with previously untreated knee chondral injuries and compare it with matched controls. All players with knee chondral injuries identified at the NFL Combine (2009-2015) were retrospectively reviewed. Players with prior knee surgery were excluded. A knee MRI for each player was reviewed; location, modified International Cartilage Repair Society (ICRS) grade (I-IV), and associated compartment subchondral edema were documented. Position, respective NFL Draft pick selection number, games started, played, snap percentage, and position-specific performance metrics during the first 2 NFL seasons were recorded for the injury and injury-free control group composed of players with (1) no prior knee injury, (2) no significant missed time prior to the NFL (≤2 total missed games in college), (3) no history of knee surgery, and (4) drafted in the respective NFL Draft following the NFL Combine. Of the 2,285 players reviewed, 101 (4.4%) had an injury without prior knee surgery. The patella (63.4%) and trochlea (34%) were most commonly affected. Defensive linemen were at highest risk for unrecognized injuries (odds ratio 1.8, P = .015). Players with previously untreated injuries, compared with controls, were picked later (mean pick: 125.8) and played (mean: 23) and started (mean: 10.4) fewer games during the initial 2 NFL seasons (P < .001 for all). Particularly, subchondral bone edema and full-thickness cartilage injuries were associated with fewer games played (P = .003). The patellofemoral joint was most commonly affected in NFL Combine participants. Previously untreated knee articular injuries in players at the NFL Combine are associated with poorer early NFL performance in comparison to uninjured players. Subchondral bone edema and full-thickness cartilage