Is “Football for All” Safe for All? Cross-Sectional Study of Disparities as Determinants of 1-Year Injury Prevalence in Youth Football Programs

PubMed Central

Dahlström, Örjan; Backe, Stefan; Ekberg, Joakim; Janson, Staffan; Timpka, Toomas

2012-01-01

Background Football (soccer) is endorsed as a health-promoting physical activity worldwide. When football programs are introduced as part of general health promotion programs, equal access and limitation of pre-participation disparities with regard to injury risk are important. The aim of this study was to explore if disparity with regard to parents’ educational level, player body mass index (BMI), and self-reported health are determinants of football injury in community-based football programs, separately or in interaction with age or gender. Methodology/Principal Findings Four community football clubs with 1230 youth players agreed to participate in the cross-sectional study during the 2006 season. The study constructs (parents’ educational level, player BMI, and self-reported health) were operationalized into questionnaire items. The 1-year prevalence of football injury was defined as the primary outcome measure. Data were collected via a postal survey and analyzed using a series of hierarchical statistical computations investigating associations with the primary outcome measure and interactions between the study variables. The survey was returned by 827 (67.2%) youth players. The 1-year injury prevalence increased with age. For youths with parents with higher formal education, boys reported more injuries and girls reported fewer injuries than expected; for youths with lower educated parents there was a tendency towards the opposite pattern. Youths reporting injuries had higher standardized BMI compared with youths not reporting injuries. Children not reporting full health were slightly overrepresented among those reporting injuries and underrepresented for those reporting no injury. Conclusion Pre-participation disparities in terms of parents’ educational level, through interaction with gender, BMI, and self-reported general health are associated with increased injury risk in community-based youth football. When introduced as a general health promotion, football associations should adjust community-based youth programs to accommodate children and adolescents with increased pre-participation injury risk. PMID:22928035

Is "football for all" safe for all? Cross-sectional study of disparities as determinants of 1-year injury prevalence in youth football programs.

PubMed

Dahlström, Örjan; Backe, Stefan; Ekberg, Joakim; Janson, Staffan; Timpka, Toomas

2012-01-01

Football (soccer) is endorsed as a health-promoting physical activity worldwide. When football programs are introduced as part of general health promotion programs, equal access and limitation of pre-participation disparities with regard to injury risk are important. The aim of this study was to explore if disparity with regard to parents' educational level, player body mass index (BMI), and self-reported health are determinants of football injury in community-based football programs, separately or in interaction with age or gender. Four community football clubs with 1230 youth players agreed to participate in the cross-sectional study during the 2006 season. The study constructs (parents' educational level, player BMI, and self-reported health) were operationalized into questionnaire items. The 1-year prevalence of football injury was defined as the primary outcome measure. Data were collected via a postal survey and analyzed using a series of hierarchical statistical computations investigating associations with the primary outcome measure and interactions between the study variables. The survey was returned by 827 (67.2%) youth players. The 1-year injury prevalence increased with age. For youths with parents with higher formal education, boys reported more injuries and girls reported fewer injuries than expected; for youths with lower educated parents there was a tendency towards the opposite pattern. Youths reporting injuries had higher standardized BMI compared with youths not reporting injuries. Children not reporting full health were slightly overrepresented among those reporting injuries and underrepresented for those reporting no injury. Pre-participation disparities in terms of parents' educational level, through interaction with gender, BMI, and self-reported general health are associated with increased injury risk in community-based youth football. When introduced as a general health promotion, football associations should adjust community-based youth programs to accommodate children and adolescents with increased pre-participation injury risk.

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

Background: Recent reports have highlighted the progressive increase in the incidence of ulnar collateral ligament (UCL) injuries to the elbow in baseball players of all levels. However, knowledge of the incidence and other epidemiological factors regarding UCL injuries, specifically in college baseball players, is currently lacking. Purpose: To evaluate, over a period of 1 year, the incidence of UCL injuries requiring surgery in National Collegiate Athletic Association (NCAA) Division I baseball programs. Study Design: Descriptive epidemiology study. Methods: A total of 155 Division I collegiate baseball programs agreed to participate in the study. Demographics (position, year, background [location of high school]) for all players on these rosters were obtained from public websites. At the conclusion of the 2017 collegiate baseball season, the athletic trainer for each program entered anonymous, detailed information on injured players through an electronic survey into a secured database. Results: All 155 teams enrolled in the study completed the electronic survey. Of the 5295 collegiate baseball players on these rosters, 134 underwent surgery for an injured UCL (2.5% of all eligible athletes), resulting in a team surgery rate of 0.86 per program for 1 year. These 134 players came from 88 teams, thus 56.8% of the study teams underwent at least 1 surgery during the year. The surgery rate was 2.5 per 100 player-seasons for all players and was significantly higher among pitchers (4.4/100 player-seasons) than nonpitchers (0.7/100 player-seasons). The surgery rate was also significantly higher in underclassmen (3.1/100 player-seasons among freshmen and sophomores) than upperclassmen (1.9/100 player-seasons among juniors and seniors) (incidence rate ratio, 1.7; 95% CI, 1.1-2.4). Players from traditionally warm-weather states did not undergo UCL surgery at a significantly different rate from players from traditionally cold-weather states (2.7/100 player-seasons vs 2.1/100 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

The Spanish "Century XXI" academy for developing elite level basketballers: design, monitoring and training methodologies.

PubMed

Calleja-González, Julio; Mielgo-Ayuso, Juan; Lekue, José Antonio; Leibar, Xabier; Erauzkin, Julen; Jukic, Igor; Ostojic, Sergej M; Delextrat, Anne; Sampaio, Jaime; Terrados, Nicolás

2016-01-01

The XXI Century Academy was a 6-year state-initiated intervention program that served as an alternative to basketball clubs for players in the u-14 and u-18 age groups in Spain, under guidelines established by the Spanish Basketball Federation. It was an important and unique project on talent development in basketball. To the best of the authors' knowledge, no evidence has been reported on long-term athlete development programs in basketball worldwide. The main aim of this report is to describe the design and evaluation methods used for the XXI Century Academy as a long-term intervention program in the elite Spanish Basketball Academy, aiming to prepare basketball players to compete at the elite level. The monitoring time lasted from 1996 to 2001. A total of 55 players were assigned to the intervention groups based on age, position, maturation level, and country of origin. During this process, participants competed in up to two categories in addition to playing competitive official matches worldwide in international tournaments in their categories and with the national team in the European and World Championships (u-14 - u-18). Participants included 1 NBA player, 3 national A Team players, 10 ACB (First Spanish League) players, 5 LEB (second League) players and 39 LEB-2 EBA (third League) players. Assessments took place in a High-Performance Sports Center (CPT FADURA-GETXO- Basque Government, Getxo, Vizcaya, Spain) and consisted of health questionnaires, anthropometric measures, blood parameters, maturation level, birth age, fitness tests, training volume and intensity, physical activity, technical and tactical training, dietary intake, supplementation and injuries. Each player was assessed 4 times per year (September, December, April, June) for 4 years (16 data points). This is a purely methodological paper describing the design and evaluation methods used in the XXI Century Project, which will be used as a basis for future reporting of results. Therefore, the results of the project will be reported in subsequent publications. The viability of the Century XXI Project protocols has been described. This national project of training in basketball closely replicates the physical and technical match-play conditions for professionals and may constitute a useful training tool.

Effects of 6 Weeks Psychological Skill Training on Team Cohesion, Self-Confidence & Anxiety: A Case of Youth Basketball Players

ERIC Educational Resources Information Center

Miçoogullari, Bülent Okan; Kirazci, Sadettin

2016-01-01

The purpose of this study was to examine the impact of a six-week psychological skill training (PST) program that is based on a cognitive-behavioral conceptual framework on team cohesion, confidence, and anxiety of an intact team. Thirty-six male basketball players, 19 athletes for the experimental group and 17 athletes for the control group, aged…

Effects of 6-week sling-based training of the external-rotator muscles on the shoulder profile in elite female high school handball players.

PubMed

Genevois, Cyril; Berthier, Philippe; Guidou, Vincent; Muller, Franck; Thiebault, Boris; Rogowski, Isabelle

2014-11-01

In women's handball, the large numbers of throws and passes make the shoulder region vulnerable to overuse injuries. Repetitive throwing motions generate imbalance between shoulder internal- and external-rotator muscles. It has not yet been established whether sling-based training can improve shoulder external-rotator muscle strength. This study investigated the effectiveness of a 6-wk strengthening program in improving shoulder functional profile in elite female high school handball players. Crossover study. National elite handball training center. 25 elite female high school handball players. The program, completed twice per week for 6 wk, included sling-based strengthening exercises using a suspension trainer for external rotation with scapular retraction and scapular retraction alone. Maximal shoulder external- and internal-rotation strength, shoulder external- and internal-rotation range of motion (ROM), and maximal throwing velocity were assessed preintervention and postintervention for dominant and nondominant sides. After sling training, external- and internal-rotation strength increased significantly for both sides (P ≤ .001, and P = .004, respectively), with the result that there was no significant change in external- and internal-rotation strength ratios for either the dominant or the nondominant shoulder. No significant differences were observed for external-rotation ROM, while internal-rotation ROM decreased moderately, in particular in the dominant shoulder (P = .005). Maximal throwing velocity remained constant for the dominant arm, whereas a significant increase was found for the nondominant arm (P = .017). This 6-wk strengthening program was effective in improving shoulder external-rotator muscle strength but resulted in a decrease in the ROM in shoulder internal rotation, while throwing velocity remained stable. Adding a stretching program to this type of sling-based training program might help avoid potential detrimental effects on shoulder ROM.

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.

Which Disc Player for Education? A Comparative Evaluation.

ERIC Educational Resources Information Center

Leveridge, Leo L.; Lyons, David S.

1983-01-01

Advantages and disadvantages of videodisc players using digital program dumps are discussed. Indicates that, although digital dumps on videodiscs can be used to deliver interactive audiovisual programs about as effectively as external computer programs, disadvantages greatly outweigh advantages. Thus, digital program dumps recorded on videodiscs…

Five-week sensory motor training program improves functional performance and postural control in young male soccer players - A blind randomized clinical trial.

PubMed

Heleno, Lucas Rafael; da Silva, Rubens A; Shigaki, Leonardo; Araújo, Cynthia Gobbi Alves; Coelho Candido, Cristiane Regina; Okazaki, Victor Hugo Alves; Frisseli, Ariobaldo; Macedo, Christiane de S Guerino

2016-11-01

Sensory motor training programs are used in the rehabilitation and prevention of injuries among soccer players. Inconsistencies are found in the literature regarding the duration of the protocols and the exercises and equipment used. To evaluate the benefits of a five-week sensory motor training program on the functional performance and postural control of young soccer players. The study sample comprised 22 young male soccer players who were evaluated using: the Figure-of-Eight Test (F8), Side Hop Test (SHT), Star Excursion Balance Test (SEBT), and a force platform. The players were randomly divided into a control group (N = 10), who continued their soccer practice sessions and an intervention group (N = 12), who continued their soccer practice sessions and were also enrolled in a supervised five-week sensory motor training program. After the five-week training program, the intervention group obtained significant results in the F8, SHT and SEBT, as well as in the following parameters: area of pressure of sway center (COP), mean velocity and mean frequency of COP. The five-week sensory motor training program, carried out with easily available and low cost equipment, was effective at improving functional performance and postural control in young soccer players. Copyright © 2016 Elsevier Ltd. All rights reserved.

SOCMATICAS Teacher's Guide.

ERIC Educational Resources Information Center

Frame, Laurence

Instructions for use of Socmaticas, a bilingual (Spanish-English), multicultural, multidisciplinary sports learning program are given in this teacher's guide. The program is based on the use of World Soccer team rosters (which include lists of players' names, ages, heights, weights, etc.) to teach English as a second language or Spanish. Students…

Comparison of three baseball-specific 6-week training programs on throwing velocity in high school baseball players.

PubMed

Escamilla, Rafael F; Ionno, Michele; deMahy, M Scott; Fleisig, Glenn S; Wilk, Kevin E; Yamashiro, Kyle; Mikla, Tony; Paulos, Lonnie; Andrews, James R

2012-07-01

Throwing velocity is an important baseball performance variable for baseball pitchers, because greater throwing velocity results in less time for hitters to make a decision to swing. Throwing velocity is also an important baseball performance variable for position players, because greater throwing velocity results in decreased time for a runner to advance to the next base. This study compared the effects of 3 baseball-specific 6-week training programs on maximum throwing velocity. Sixty-eight high school baseball players 14-17 years of age were randomly and equally divided into 3 training groups and a nontraining control group. The 3 training groups were the Throwers Ten (TT), Keiser Pneumatic (KP), and Plyometric (PLY). Each training group trained 3 d·wk(-1) for 6 weeks, which comprised approximately 5-10 minutes for warm-up, 45 minutes of resistance training, and 5-10 for cool-down. Throwing velocity was assessed before (pretest) and just after (posttest) the 6-week training program for all the subjects. A 2-factor repeated measures analysis of variance with post hoc paired t-tests was used to assess throwing velocity differences (p < 0.05). Compared with pretest throwing velocity values, posttest throwing velocity values were significantly greater in the TT group (1.7% increase), the KP group (1.2% increase), and the PLY group (2.0% increase) but not significantly different in the control group. These results demonstrate that all 3 training programs were effective in increasing throwing velocity in high school baseball players, but the results of this study did not demonstrate that 1 resistance training program was more effective than another resistance training program in increasing throwing velocity.

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 effective programs for softball athletes.

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 athletes adapt to the demands of the sport differently; thus, stretching/strengthening programs designed for baseball may not be the most effective programs for softball athletes. PMID:25098655

The Effect of a Combined High-Intensity Plyometric and Speed Training Program on the Running and Jumping Ability of Male Handball Players

PubMed Central

Cherif, Monsef; Said, Mohamed; Chaatani, Sana; Nejlaoui, Olfa; Gomri, Daghbaji; Abdallah, Aouidet

2012-01-01

Purpose The aim of this study was to investigate the effect of a combined program including sprint repetitions and drop jump training in the same session on male handball players. Methods Twenty-two male handball players aged more than 20 years were assigned into 2 groups: experimental group (n=11) and control group (n=11). Selection was based on variables “axis” and “lines”, goalkeepers were not included. The experimental group was subjected to 2 testing periods (test and retest) separated by 12 weeks of an additional combined plyometric and running speed training program. The control group performed the usual handball training. The testing period comprised, at the first day, a medical checking, anthropometric measurements and an incremental exercise test called yo-yo intermittent recovery test. 2 days later, participants performed the Repeated Sprint Ability test (RSA), and performed the Jumping Performance using 3 different events: Squat jump (SJ), Countermovement jump without (CMJ) and with arms (CMJA), and Drop jump (DJ). At the end of the training period, participants performed again the repeated sprint ability test, and the jumping performance. Results The conventional combined program improved the explosive force ability of handball players in CMJ (P=0.01), CMJA (P=0.01) and DJR (P=0.03). The change was 2.78, 2.42 and 2.62% respectively. No significant changes were noted in performances of the experimental group at the squat jump test and the drop jump with the left leg test. The training intervention also improved the running speed ability of the experimental group (P=0.003). No statistical differences were observed between lines or axes. Conclusion Additional combined training program between sprint repetition and vertical jump in the same training session positively influence the jumping ability and the sprint ability of handball players. PMID:22461962

The effect of a combined high-intensity plyometric and speed training program on the running and jumping ability of male handball players.

PubMed

Cherif, Monsef; Said, Mohamed; Chaatani, Sana; Nejlaoui, Olfa; Gomri, Daghbaji; Abdallah, Aouidet

2012-03-01

The aim of this study was to investigate the effect of a combined program including sprint repetitions and drop jump training in the same session on male handball players. Twenty-two male handball players aged more than 20 years were assigned into 2 groups: experimental group (n=11) and control group (n=11). Selection was based on variables "axis" and "lines", goalkeepers were not included. The experimental group was subjected to 2 testing periods (test and retest) separated by 12 weeks of an additional combined plyometric and running speed training program. The control group performed the usual handball training. The testing period comprised, at the first day, a medical checking, anthropometric measurements and an incremental exercise test called yo-yo intermittent recovery test. 2 days later, participants performed the Repeated Sprint Ability test (RSA), and performed the Jumping Performance using 3 different events: Squat jump (SJ), Countermovement jump without (CMJ) and with arms (CMJA), and Drop jump (DJ). At the end of the training period, participants performed again the repeated sprint ability test, and the jumping performance. The conventional combined program improved the explosive force ability of handball players in CMJ (P=0.01), CMJA (P=0.01) and DJR (P=0.03). The change was 2.78, 2.42 and 2.62% respectively. No significant changes were noted in performances of the experimental group at the squat jump test and the drop jump with the left leg test. The training intervention also improved the running speed ability of the experimental group (P=0.003). No statistical differences were observed between lines or axes. Additional combined training program between sprint repetition and vertical jump in the same training session positively influence the jumping ability and the sprint ability of handball players.

Longitudinal motor performance development in early adolescence and its relationship to adult success: An 8-year prospective study of highly talented soccer players.

PubMed

Leyhr, Daniel; Kelava, Augustin; Raabe, Johannes; Höner, Oliver

2018-01-01

Several talent identification and development (TID) programs in soccer have implemented diagnostics to measure players' motor performance. Yet, there is a lack of research investigating the relationship between motor development in adolescence and future, adult performance. This longitudinal study analyzed the three-year development of highly talented young soccer players' speed abilities and technical skills and examined the relevance of this development to their adult success. The current research sample consisted of N = 1,134 players born between 1993 and 1995 who were selected for the German Soccer Association's TID program and participated in nationwide motor diagnostics (sprinting, agility, dribbling, ball control, shooting) four times between the Under 12 (U12) and Under 15 (U15) age class. Relative age (RA) was assessed for all players, and a total motor score was calculated based on performances in the individual tests. In order to investigate players' future success, participants were divided into two groups according to their adult performance level (APL) in the 2014/2015 season: Elite (1st-5th German division; N = 145, 12.8%) and non-elite players (lower divisions; N = 989, 87.2%). Using multilevel regression analyses each motor performance was predicted by Time, Time2 (level-1 predictors), APL, and RA (level-2 covariates) with simultaneous consideration for interaction effects between the respective variables. Time and Time2 were significant predictors for each test performance. A predictive value for RA was confirmed for sprinting and the total motor score. A significant relationship between APL and the motor score as well as between APL and agility, dribbling, ball control, and shooting emerged. Interaction effects distinctly failed to reach significance. The study found a non-linear improvement in players' performance for all considered motor performance factors over a three-year period from early to middle adolescence. While their predictive value for future success was confirmed by a significant relationship between APL and most of the considered factors, there was no significant interaction between APL and Time. These findings indicate that future elite players had already been better at the beginning of the TID program and maintained this high level throughout their promotion from U12 to U15.

Epidemiology of injuries in Australian school level rugby union.

PubMed

Leung, Felix T; Franettovich Smith, Melinda M; Brown, Mark; Rahmann, Ann; Mendis, M Dilani; Hides, Julie A

2017-08-01

There is a high incidence of injuries in rugby union due to the physical nature of the game. There is a lack of large-scale injury surveillance data reported for school level rugby players of different ages. Our study aimed to investigate the frequency and nature of injuries being sustained during an Australian school level rugby union season. Prospective observational study. Injury surveillance was conducted on 3585 rugby players from all 8 schools participating in an interschool rugby competition in Queensland, Australia. Match injury data were collected using paper-based injury recording forms during the season using a 'medical-attention' injury definition for each age group from opens (17 and 18year olds) through to year 5 teams (9-10year olds). There were 332 injuries recorded over 14,029 player hours during the season. The overall rate of injury was 23.7/1000 player hours (95% CI, 21.2-26.3). The incidence of upper and lower limb injuries were 6.3 and 5.6 injuries/1000 player hours respectively (95% CI, 5.1-7.8 and 4.5-7.0). The incidence of suspected concussion injuries was 4.3/1000 player hours (95% CI, 3.6-5.5). Injuries differed across age groups and tackling was the most common mechanism of injury. The injury patterns observed in this large sample of players could be used to guide injury prevention programs in school level rugby union. Injury prevention programs should include age appropriate interventions and focus on improving the techniques used during the contact phase of rugby. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Performance factors in women's team handball: physical and physiological aspects--a review.

PubMed

Manchado, Carmen; Tortosa-Martínez, Juan; Vila, Helena; Ferragut, Carmen; Platen, Petra

2013-06-01

Team handball is an Olympic sport played professionally in many European countries. Nevertheless, a scientific knowledge regarding women's elite team handball demands is limited. Thus, the purpose of this article was to review a series of studies (n = 33) on physical characteristics, physiological attributes, physical attributes, throwing velocity, and on-court performances of women's team handball players. Such empirical and practical information is essential to design and implement successful short-term and long-term training programs for women's team handball players. Our review revealed that (a) players that have a higher skill level are taller and have a higher fat-free mass; (b) players who are more aerobically resistant are at an advantage in international level women team handball; (c) strength and power exercises should be emphasized in conditioning programs, because they are associated with both sprint performance and throwing velocity; (d) speed drills should also be implemented in conditioning programs but after a decrease in physical training volume; (e) a time-motion analysis is an effective method of quantifying the demands of team handball and provides a conceptual framework for the specific physical preparation of players. According to our results, there are only few studies on on-court performance and time-motion analysis for women's team handball players, especially concerning acceleration profiles. More studies are needed to examine the effectiveness of different training programs of women's team handball players' physiological and physical attributes.

Nutrient intake and food habits of soccer players: analyzing the correlates of eating practice.

PubMed

García-Rovés, Pablo M; García-Zapico, Pedro; Patterson, Angeles M; Iglesias-Gutiérrez, Eduardo

2014-07-18

Despite the impact and popularity of soccer, and the growing field of soccer-related scientific research, little attention has been devoted to the nutritional intake and eating habits of soccer players. Moreover, the few studies that have addressed this issue suggest that the nutritional intake of soccer players is inadequate, underscoring the need for better adherence to nutritional recommendations and the development and implementation of nutrition education programs. The objective of these programs would be to promote healthy eating habits for male and female soccer players of all ages to optimize performance and provide health benefits that last beyond the end of a player's career. To date, no well-designed nutrition education program has been implemented for soccer players. The design and implementation of such an intervention requires a priori knowledge of nutritional intake and other correlates of food selection, such as food preferences and the influence of field position on nutrient intake, as well as detailed analysis of nutritional intake on match days, on which little data is available. Our aim is to provide an up-to-date overview of the nutritional intake, eating habits, and correlates of eating practice of soccer players.

Effect of Core Training Program on Physical Functional Performance in Female Soccer Players

ERIC Educational Resources Information Center

Taskin, Cengiz

2016-01-01

The purpose of this study was to determine the effect of core training program on speed, acceleration, vertical jump, and standing long jump in female soccer players. A total of 40 female soccer players volunteered to participate in this study. They were divided randomly into 1 of 2 groups: core training group (CTG; n = 20) and control group (CG;…

Determining skill transferability of action games as a method to reduce in-vehicle phone distractions.

PubMed

Rupp, M; McConnell, D S; Smither, J A

2012-01-01

Distracted driving has been shown to be a safety issue in numerous studies. To combat this problem, in-vehicle technology, legislation, media interventions, and other methods have been proposed and attempted. However research indicates that the drivers themselves may circumvent, ignore, or not be able to react in time for these interventions to be effective. Therefore research into training programs for drivers may improve reaction time under distraction. Research indicates that action game players have faster reaction times and more attentional resources than non-players on paper-based tests. However, transferability to driving has not been studied yet. This paper outlines a study to determine if action game players perform better at a driving task based on frequency of game-play. Participants will be placed into two groups of play (high vs. low) and tested against two levels of distraction (none vs. phone conversation). It is expected that participants who play higher frequency of action games will perform better under distraction than lower frequency players. Driver performance, conversation recall, frequency and durations of eye fixations will be analyzed based on previous research which has validated those variables as a measure of distraction and higher workload.

Eccentric Exercises Reduce Hamstring Strains in Elite Adult Male Soccer Players: A Critically Appraised Topic.

PubMed

Shadle, Ian B; Cacolice, Paul A

2017-11-01

Clinical Scenario: Hamstring strains are a common sport-related injury, which may limit athletic performance for an extended period of time. These injuries are common in the soccer setting. As such, it is important to determine an appropriate prevention program to minimize the risk of such an injury for these athletes. Eccentric hamstring training may be an effective and practical hamstring strain prevention strategy. What is the effect of eccentric exercises on hamstring strain prevention in adult male soccer players? Summary of Key Findings: Current literature was searched for studies of level 2 evidence or higher that investigated the effect of eccentric exercises in preventing hamstring strains in adult male soccer players. Three articles returned from the literature search met the inclusion criteria. A fourth article looked at differences in strength gains between eccentric and concentric hamstring strengthening exercises, but did not record hamstring strain incidence. A fifth article, a systematic review, met all the criteria except for the correct population. Of the 3 studies, 2 were randomized control trails and 1 was a cohort study. Clinical Bottom Line: There is robust supportive evidence that eccentric hamstring exercises can prevent a hamstring injury to an elite adult male soccer player. Therefore, it is recommended that athletic trainers and other sports medicine providers evaluate current practices relating to reducing hamstring strains and consider implementing eccentric exercise based prevention programs. Strength of Recommendation: All evidence was attained from articles with a level of evidence 2b or higher, based on the Center for Evidence-Based Medicine (CEBM) criteria, stating that eccentric exercises can decrease hamstring strains.

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

How to know and choose online games: differences between current and potential players.

PubMed

Teng, Ching-I; Lo, Shao-Kang; Wang, Pe-Cheng

2007-12-01

This study investigated how different adolescent players acquire game information and the criteria they use in choosing online games and found that (1) current players generally use comprehensive information sources more than potential players do; (2) current players rely on free trials and smooth display of motion graphics as choice criteria more than potential players do; (3) potential players rely on the look of advertisements more than current players do; (4) both current and potential players most likely use word-of-mouth and gaming programs on TV as information sources; and (5) endorser attractiveness is ranked the least important among six choice criteria by both current and potential players.

The Epidemiology and Effect of Sliding Injuries in Major and Minor League Baseball Players.

PubMed

Camp, Christopher L; Curriero, Frank C; Pollack, Keshia M; Mayer, Stephanie W; Spiker, Andrea M; D'Angelo, John; Coleman, Struan H

2017-08-01

Although sliding occurs frequently in professional baseball, little is known about the epidemiology and effect of injuries that occur during sliding in this population of elite athletes. To describe the incidence and characteristics of sliding injuries, determine their effect in terms of time out of play, and identify common injury patterns that may represent appropriate targets for injury prevention programs in the future. Descriptive epidemiologic study. All offensive sliding injuries occurring in Major League Baseball (MLB) and Minor League Baseball (MLB) that resulted in time out of play during a span of 5 seasons (2011-2015) were identified. In addition to player demographics, data extracted included time out of play, location on field where injury occurred, level of play, treatment (surgical vs nonsurgical), direction of slide (head vs feet first), body region injured, and diagnosis. Descriptive statistics were used to describe the distribution of these injuries, and injury rates were calculated per slide. From 2011 to 2015, 1633 injuries occurred as a result of a slide. The total number of days missed per season was 4263. Surgical intervention was required for 134 (8.2%) injuries, and the mean days missed was 66.5 for players treated surgically and 12.3 days for players treated nonoperatively ( P < .001). MLB players were more likely than MiLB players to require surgical intervention (12.3% vs 7.5%, P = .019). Injuries to the hands/fingers represented 25.3% of all injuries and 31.3% of those requiring surgery. Although the majority of injuries occurred at second base (57%), the per-slide injury rate was similar across all bases ( P = .991). The estimated overall frequency of injury in MLB was once per every 336 slides, and the rate of injury for head- and feet-first slides was 1 in 249 and 413 slides, respectively ( P = .119). Injuries occurring while sliding in professional baseball result in a significant amount of time out of play for these elite athletes. Injuries occurring at second base and those occurring to the hands and fingers were most prevalent and may be an appropriate target for future injury prevention programs.

Influence of age, sex, technique, and exercise program on movement patterns after an anterior cruciate ligament injury prevention program in youth soccer players.

PubMed

DiStefano, Lindsay J; Padua, Darin A; DiStefano, Michael J; Marshall, Stephen W

2009-03-01

Anterior cruciate ligament (ACL) injury prevention programs show promising results with changing movement; however, little information exists regarding whether a program designed for an individual's movements may be effective or how baseline movements may affect outcomes. A program designed to change specific movements would be more effective than a "one-size-fits-all" program. Greatest improvement would be observed among individuals with the most baseline error. Subjects of different ages and sexes respond similarly. Randomized controlled trial; Level of evidence, 1. One hundred seventy-three youth soccer players from 27 teams were randomly assigned to a generalized or stratified program. Subjects were videotaped during jump-landing trials before and after the program and were assessed using the Landing Error Scoring System (LESS), which is a valid clinical movement analysis tool. A high LESS score indicates more errors. Generalized players performed the same exercises, while the stratified players performed exercises to correct their initial movement errors. Change scores were compared between groups of varying baseline errors, ages, sexes, and programs. Subjects with the highest baseline LESS score improved the most (95% CI, -3.4 to -2.0). High school subjects (95% CI, -1.7 to -0.98) improved their technique more than pre-high school subjects (95% CI, -1.0 to -0.4). There was no difference between the programs or sexes. Players with the greatest amount of movement errors experienced the most improvement. A program's effectiveness may be enhanced if this population is targeted.

Evaluation of a Psychological Skill Training Program on Mental Toughness and Psychological Wellbeing for Professional Soccer Players

ERIC Educational Resources Information Center

Miçoogullari, Bülent Okan; Ekmekçi, Ridvan

2017-01-01

The purpose of this study was to evaluate the effectiveness of psychological skills training (PST) in enhancing mental toughness among Turkish professional soccer team. Sixteen weeks of cognitive-behavioral conceptual framework-based PST program designed according to factors (confidence-constancy-control) of Sport Mental Toughness Questionnaire…

Effects of volume-based overload plyometric training on maximal-intensity exercise adaptations in young basketball players.

PubMed

Asadi, Abbas; Ramirez-Campillo, Rodrigo; Meylan, Cesar; Nakamura, Fabio Y; Cañas-Jamett, Rodrigo; Izquierdo, Mikel

2017-12-01

The aim of the present study was to compare maximal-intensity exercise adaptations in young basketball players (who were strong individuals at baseline) participating in regular basketball training versus regular plus a volume-based plyometric training program in the pre-season period. Young basketball players were recruited and assigned either to a plyometric with regular basketball training group (experimental group [EG]; N.=8), or a basketball training only group (control group [CG]; N.=8). The athletes in EG performed periodized (i.e., from 117 to 183 jumps per session) plyometric training for eight weeks. Before and after the intervention, players were assessed in vertical and broad jump, change of direction, maximal strength and a 60-meter sprint test. No significant improvements were found in the CG, while the EG improved vertical jump (effect size [ES] 2.8), broad jump (ES=2.4), agility T test (ES=2.2), Illinois agility test (ES=1.4), maximal strength (ES=1.8), and 60-m sprint (ES=1.6) (P<0.05) after intervention, and the improvements were greater compared to the CG (P<0.05). Plyometric training in addition to regular basketball practice can lead to meaningful improvements in maximal-intensity exercise adaptations among young basketball players during the pre-season.

The effect of small-sided games with different levels of opposition on the tactical behaviour of young footballers with different levels of sport expertise.

PubMed

Práxedes, Alba; Moreno, Alberto; Gil-Arias, Alexander; Claver, Fernando; Del Villar, Fernando

2018-01-01

To optimize players' tactical abilities, coaches need to design training sessions with representative learning tasks, such as, small-sided games. Moreover, it is necessary to adapt the complexity of the tasks to the skill level of the athletes to maximally improve their perceptual, visual and attentive abilities. The objective of this study was to analyze the effect of two teaching programs, each utilizing modified games with varied levels of opposition, on decision-making and action execution in young players with different levels of sports expertise. 19 football players (U12), separated into two ability groups (Average versus Low skill-level), participated in a series of training sessions that were spread over 4 phases: Pre-intervention 1, Intervention 1 (teaching program based on modified games with numerical superiority in attack), Pre-intervention 2 and Intervention 2 (teaching program based on modified games with numerical equality). Each intervention phase lasted 14 sessions. Decision-making and the execution of pass action during league matches over the same period were evaluated using the Game Performance Evaluation Tool (GPET). The Average skill-level group showed significant differences after the first intervention in decision-making and execution of the pass action (decision-making, p = .015; execution, p = .031), but not after the second intervention (decision-making, p = 1.000; execution, p = 1.000). For the Low skill-level group, significant differences were only observed in the execution of passing between the first and last phases (p = .014). These findings seem to indicate that for groups with an average level of expertise, training with numerical superiority in attack provides players with more time to make better decisions and to better execute actions. However, for lower-level groups programs may take longer to facilitate improvement. Nevertheless, numerical equality did not result in improvement for either group.

Examination of Performance Levels of Wheelchair Basketball Players Playing in Different Leagues

PubMed Central

2018-01-01

This research was conducted to examine the anthropometric and biometric features of the elite wheelchair basketball players in different league levels, and to evaluate them with regards to field tests particular to wheelchair basketball. A sample of 21 male players volunteered to participate in the research with similar classification points, 12 of whom were from Turkey Wheelchair Basketball First League and 9 of whom were from the Second League. Anthropometric measurements, biometric features of the players and their skill test scores particular to wheelchair basketball were detected. The anthropometric measurements were taken over dominant extremity. SPSS 21.0 program was used in the analysis of the data, and minimum, maximum, arithmetic mean, and standard deviation values were determined. Intergroup differences were determined with Mann–Whitney U analysis. Significance level was admitted as p < 0.05. As a conclusion, it was determined that wheelchair basketball players had similar anthropometric features in the First and Second League levels, and that there was no difference based on the league level they were playing, and moreover, that bio-motor features and skills particular to wheelchair basketball were decisive on the levels of the leagues the players were taking part.

[Effect of Core Muscle Strengthening Exercises (Including Plank and Side Plank) on Injury Rate in Male Adult Soccer Players: A Systematic Review].

PubMed

Blasimann, Angela; Eberle, Simon; Scuderi, Manuel Markus

2018-03-01

 Soccer is seen as highly intensive sport with an increased injury rate. Male adults are the players with the highest injury incidence. Accordingly, the importance of core muscle strengthening to prevent injury has increased in the past few years. Up to date, core muscle strengthening plays an important role in different prevention programs, such as the "FIFA 11 +". The aim of this systematic review was to investigate the effect of core muscle strengthening on injury rate in male adult soccer players, including at least the known and easy exercises "plank" and "side plank", on injury rate in male adult soccer players.  The databases PubMed, PEDro, Cochrane Library, SPORTDiscus and Cinahl were searched systematically. Included studies had to comprise exercises for core muscles as an intervention (as a part of a prevention program) for adult male soccer players. The control group had to continue their usual exercise routine. The exercises "plank" and "side plank" were mandatory elements of the training program. The number of injuries and/or the injury rate (per 1000 hours) were defined as outcomes. The quality of the included studies was assessed with the PEDro scale and the Risk of Bias tool.  Seven studies with 2491 participants in total could be included. Two studies found a significant decrease in the injury rate in the intervention group (p < 0.05, p < 0.001 respectively). In two studies, no significance level was reported, but the training showed preventive effects in the intervention group. In the other three studies, no significant changes in the injury rate were found (p > 0.05).  The seven included studies differed greatly with respect to the applied methods, the chosen interventions and the obtained results. Furthermore, core muscles were never trained separately but were always part of a program containing other preventive elements. Therefore, it was difficult to compare the studies. However, prevention programs including strengthening exercises for core muscles tend to positively affect the injury rate. Based on the literature found, the research question cannot definitively be answered. In the future, further studies are needed which investigate the effect of isolated core muscle training on the injury rate of soccer players. © Georg Thieme Verlag KG Stuttgart · New York.

Evaluating the Crisis Response Strategies of a University Basketball Program: How Do Reactions Differ Based on Apologies, Crisis Severity, and Team Identification?

ERIC Educational Resources Information Center

Isaacson, Thomas E.

2012-01-01

Negative news about collegiate sports teams in the United States is nearly unavoidable for most universities. The sheer number of athletes involved in multiple programs at major universities increases the likelihood of problems. American football programs alone include rosters of 100 or more players, and the total number of athletes at National…

The Cognitive and Motivation Intervention Program in Youth Female Volleyball Players.

PubMed

Claver, Fernando; Jiménez, Ruth; Gil-Arias, Alexander; Moreno, Alberto; Moreno, M Perla

2017-10-01

This study, grounded in Self-Determination Theory (Deci and Ryan, 1985, 2002) was aimed to determine the influence of a cognitive-motivational intervention program, to improve the basic psychological need satisfaction of autonomy and competence, autonomous motivation, procedural knowledge, perceived performance and sport commitment, in youth volleyball players. Participants included 34 Under-19 female volleyball players. A quasi-experimental design was carried out with an experimental group (n = 16; M = 17.45; SD = .45) and a control group (n = 18; M = 16.64; SD = .70). The experimental group followed a multidimensional intervention program comprised of 24 sessions held over three months (two training sessions per week). It was based on two strategies: giving athletes the possibility of choice in specific training tasks (proposing training situations with several action alternatives) and questioning (cognitively involving players through tactical questions). A repeated-measures MANOVA 2 (group: experimental and control) x 2 (time: pre-test and post-test) was used to analyse the effect of Group x Time interaction. The results of the inter-group analysis showed significant differences in the post-test measurement between the experimental group and the control group (in favour of the experimental group) in the variables: basic psychological need satisfaction of autonomy and competence, autonomous motivation, procedural knowledge, perceived performance and sport commitment. Given the relevance of the cognitive-motivational processes, not only for performance but also for sport commitment, this intervention has important implications for sport coaching.

Data-Based Interval Throwing Programs for Collegiate Softball Players

PubMed Central

Axe, Michael J.; Windley, Thomas C.; Snyder-Mackler, Lynn

2002-01-01

Objective: To construct interval throwing programs followed by a simulated game for collegiate softball players at all positions. The programs are intended to be used as functional progressions within a comprehensive rehabilitation program for an injured athlete or to augment off-season conditioning workouts. Design and Setting: We collected data over a single season of National Collegiate Athletic Association softball at the University of Delaware and Goldey Beacom College. We observed 220 half-innings of play and 2785 pitches during data collection. Subjects: The subjects were collegiate-level softball players at all positions of play. Measurements: We recorded the number of pitches for pitchers. For catchers, we recorded the number of sprints to back up a play, time in the squat stance, throws back to the pitcher, and the perceived effort and distance of all other throws. We also collected the perceived effort and distance of all throws for infielders and outfielders. Results: Pitchers threw an average of 89.61 pitches per game; catchers were in the squat stance 14.13 minutes per game; infielders threw the ball between 4.28 times per game and 6.30 times per game; and outfielders threw distances of up to 175 feet. Conclusions: We devised the interval throwing programs from the data collected, field dimensions, the types of injuries found to occur in softball, and a general understanding of tissue healing. We designed programs that allow a safe and efficient progressive return to sport. PMID:12937435

Converting laserdisc video to digital video: a demonstration project using brain animations.

PubMed

Jao, C S; Hier, D B; Brint, S U

1995-01-01

Interactive laserdiscs are of limited value in large group learning situations due to the expense of establishing multiple workstations. The authors implemented an alternative to laserdisc video by using indexed digital video combined with an expert system. High-quality video was captured from a laserdisc player and combined with waveform audio into an audio-video-interleave (AVI) file format in the Microsoft Video-for-Windows environment (Microsoft Corp., Seattle, WA). With the use of an expert system, a knowledge-based computer program provided random access to these indexed AVI files. The program can be played on any multimedia computer without the need for laserdiscs. This system offers a high level of interactive video without the overhead and cost of a laserdisc player.

Nutrient Intake and Food Habits of Soccer Players: Analyzing the Correlates of Eating Practice

PubMed Central

García-Rovés, Pablo M.; García-Zapico, Pedro; Patterson, Ángeles M.; Iglesias-Gutiérrez, Eduardo

2014-01-01

Despite the impact and popularity of soccer, and the growing field of soccer-related scientific research, little attention has been devoted to the nutritional intake and eating habits of soccer players. Moreover, the few studies that have addressed this issue suggest that the nutritional intake of soccer players is inadequate, underscoring the need for better adherence to nutritional recommendations and the development and implementation of nutrition education programs. The objective of these programs would be to promote healthy eating habits for male and female soccer players of all ages to optimize performance and provide health benefits that last beyond the end of a player’s career. To date, no well-designed nutrition education program has been implemented for soccer players. The design and implementation of such an intervention requires a priori knowledge of nutritional intake and other correlates of food selection, such as food preferences and the influence of field position on nutrient intake, as well as detailed analysis of nutritional intake on match days, on which little data is available. Our aim is to provide an up-to-date overview of the nutritional intake, eating habits, and correlates of eating practice of soccer players. PMID:25045939

Efficacy of the FIFA 11+ Injury Prevention Program in the Collegiate Male Soccer Player

PubMed Central

Silvers-Granelli, Holly; Mandelbaum, Bert; Adeniji, Ola; Insler, Stephanie; Bizzini, Mario; Pohlig, Ryan; Junge, Astrid; Snyder-Mackler, Lynn; Dvorak, Jiri

2016-01-01

Background The Fédération Internationale de Football Association (FIFA) 11+ program has been shown to be an effective injury prevention program in the female soccer cohort, but there is a paucity of research to demonstrate its efficacy in the male population. Hypothesis To examine the efficacy of the FIFA 11+ program in men's collegiate United States National Collegiate Athletic Association (NCAA) Division I and Division II soccer. Study Design Randomized controlled trial; Level of evidence, 1. Methods Before the commencement of the fall 2012 season, every NCAA Division I and Division II men's collegiate soccer team (N = 396) was solicited to participate in this research study. Human ethics review board approval was obtained through Quorum Review IRB. Sixty-five teams were randomized: 34 to the control group (CG; 850 players) and 31 to the intervention group (IG; 675 players). Four teams in the IG did not complete the study, reducing the number for analysis to 61. The FIFA 11+ injury prevention program served as the intervention and was utilized weekly. Athlete-exposures (AEs), compliance, and injury data were recorded using a secure Internet-based system. Results In the CG, 665 injuries (mean ± SD, 19.56 ± 11.01) were reported for 34 teams, which corresponded to an incidence rate (IR) of 15.04 injuries per 1000 AEs. In the IG, 285 injuries (mean ± SD, 10.56 ± 3.64) were reported for 27 teams, which corresponded to an IR of 8.09 injuries per 1000 AEs. Total days missed because of injury were significantly higher for the CG (mean ± SD, 13.20 ± 26.6 days) than for the IG (mean ± SD, 10.08 ± 14.68 days) (P = .007). There was no difference for time loss due to injury based on field type (P = .341). Conclusion The FIFA 11+ significantly reduced injury rates by 46.1% and decreased time loss to injury by 28.6% in the competitive male collegiate soccer player (rate ratio, 0.54 [95% CI, 0.49-0.59]; P < .0001) (number needed to treat = 2.64). PMID:26378030

Simple and powerful visual stimulus generator.

PubMed

Kremlácek, J; Kuba, M; Kubová, Z; Vít, F

1999-02-01

We describe a cheap, simple, portable and efficient approach to visual stimulation for neurophysiology which does not need any special hardware equipment. The method based on an animation technique uses the FLI autodesk animator format. This form of the animation is replayed by a special program ('player') providing synchronisation pulses toward recording system via parallel port. The 'player is running on an IBM compatible personal computer under MS-DOS operation system and stimulus is displayed on a VGA computer monitor. Various stimuli created with this technique for visual evoked potentials (VEPs) are presented.

A Multifactorial, Criteria-based Progressive Algorithm for Hamstring Injury Treatment.

PubMed

Mendiguchia, Jurdan; Martinez-Ruiz, Enrique; Edouard, Pascal; Morin, Jean-Benoît; Martinez-Martinez, Francisco; Idoate, Fernando; Mendez-Villanueva, Alberto

2017-07-01

Given the prevalence of hamstring injuries in football, a rehabilitation program that effectively promotes muscle tissue repair and functional recovery is paramount to minimize reinjury risk and optimize player performance and availability. This study aimed to assess the concurrent effectiveness of administering an individualized and multifactorial criteria-based algorithm (rehabilitation algorithm [RA]) on hamstring injury rehabilitation in comparison with using a general rehabilitation protocol (RP). Implementing a double-blind randomized controlled trial approach, two equal groups of 24 football players (48 total) completed either an RA group or a validated RP group 5 d after an acute hamstring injury. Within 6 months after return to sport, six hamstring reinjuries occurred in RP versus one injury in RA (relative risk = 6, 90% confidence interval = 1-35; clinical inference: very likely beneficial effect). The average duration of return to sport was possibly quicker (effect size = 0.34 ± 0.42) in RP (23.2 ± 11.7 d) compared with RA (25.5 ± 7.8 d) (-13.8%, 90% confidence interval = -34.0% to 3.4%; clinical inference: possibly small effect). At the time to return to sport, RA players showed substantially better 10-m time, maximal sprinting speed, and greater mechanical variables related to speed (i.e., maximum theoretical speed and maximal horizontal power) than the RP. Although return to sport was slower, male football players who underwent an individualized, multifactorial, criteria-based algorithm with a performance- and primary risk factor-oriented training program from the early stages of the process markedly decreased the risk of reinjury compared with a general protocol where long-length strength training exercises were prioritized.

Adding a post-training FIFA 11+ exercise program to the pre-training FIFA 11+ injury prevention program reduces injury rates among male amateur soccer players: a cluster-randomised trial.

PubMed

Al Attar, Wesam Saleh A; Soomro, Najeebullah; Pappas, Evangelos; Sinclair, Peter J; Sanders, Ross H

2017-10-01

Does adding a post-training Fédération Internationale de Football Association (FIFA) 11+ exercise program to the pre-training FIFA 11+ injury prevention program reduce injury rates among male amateur soccer players? Cluster-randomised, controlled trial with concealed allocation. Twenty-one teams of male amateur soccer players aged 14 to 35 years were randomly assigned to the experimental group (n=10 teams, 160 players) or the control group (n=11 teams, 184 players). Both groups performed pre-training FIFA 11+ exercises for 20minutes. The experimental group also performed post-training FIFA 11+ exercises for 10minutes. The primary outcomes measures were incidence of overall injury, incidence of initial and recurrent injury, and injury severity. The secondary outcome measure was compliance to the experimental intervention (pre and post FIFA 11+ program) and the control intervention (pre FIFA 11+ program). During one season, 26 injuries (team mean=0.081 injuries/1000 exposure hours, SD=0.064) were reported in the experimental group, and 82 injuries were reported in the control group (team mean=0.324 injuries/1000hours, SD=0.084). Generalised Estimating Equations were applied with an intention-to-treat analysis. The pre and post FIFA 11+ program reduced the total number of injuries (χ 2 (1)=11.549, p=0.001) and the incidence of initial injury (χ 2 (2)=8.987, p=0.003) significantly more than the pre FIFA 11+ program alone. However, the odds of suffering a recurrent injury were not different between the two groups (χ 2 (1)=2.350, p=0.125). Moreover, the severity level of injuries was not dependent upon whether or not the pre and post FIFA 11+ program was implemented (χ 2 (1)=0.016, p=0.898). Implementation of the FIFA 11+ program pre-training and post-training reduced overall injury rates in male amateur soccer players more than the pre FIFA 11+ program alone. ACTRN12615001206516. [Al Attar WSA, Soomro N, Pappas E, Sinclair PJ, Sanders RH (2017) Adding a post-training FIFA 11+ exercise program to the pre-training FIFA 11+ injury prevention program reduces injury rates among male amateur soccer players: a cluster-randomised trial. Journal of Physiotherapy 63: 235-242]. Copyright © 2017 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

Including the Copenhagen Adduction Exercise in the FIFA 11+ Provides Missing Eccentric Hip Adduction Strength Effect in Male Soccer Players: A Randomized Controlled Trial.

PubMed

Harøy, Joar; Thorborg, Kristian; Serner, Andreas; Bjørkheim, André; Rolstad, Linn E; Hölmich, Per; Bahr, Roald; Andersen, Thor Einar

2017-11-01

The FIFA 11+ was developed as a complete warm-up program to prevent injuries in soccer players. Although reduced hip adduction strength is associated with groin injuries, none of the exercises included in the FIFA 11+ seem to specifically target hip adduction strength. To investigate the effect on eccentric hip adduction strength of the FIFA 11+ warm-up program with or without the Copenhagen adduction exercise. Randomized controlled trial; Level of evidence, 1. We recruited 45 eligible players from 2 U19 elite male soccer teams. Players were randomized into 2 groups; 1 group carried out the standard FIFA 11+ program, while the other carried out the FIFA 11+ but replaced the Nordic hamstring exercise with the Copenhagen adduction exercise. Both groups performed the intervention 3 times weekly for 8 weeks. Players completed eccentric strength and sprint testing before and after the intervention. Per-protocol analyses were performed, and 12 players were excluded due to low compliance (<67% of sessions completed). The main outcome was eccentric hip adduction strength (N·m/kg). Between-group analyses revealed a significantly greater increase in eccentric hip adduction strength of 0.29 Nm/kg (8.9%; P = .01) in favor of the group performing the Copenhagen adduction exercise, whereas no within-group change was noted in the group that used the standard FIFA 11+ program (-0.02 N·m/kg [-0.7%]; P = .69). Including the Copenhagen adduction exercise in the FIFA 11+ program increases eccentric hip adduction strength, while the standard FIFA 11+ program does not. Registration: Registration: ISRCTN13731446 (International Standard Randomised Controlled Trial Number registry).

The Effects of Individualized Resistance Strength Programs on Knee Muscular Imbalances in Junior Elite Soccer Players

PubMed Central

Śliwowski, Robert; Jadczak, Łukasz; Hejna, Rafał; Wieczorek, Andrzej

2015-01-01

The purpose of this study was to investigate the effects of a resistance training program on the muscular strength of soccer players’ knees that initially presented unilateral and bilateral differences. For this study, a team of 24 male well-trained junior soccer players was divided into two strength program training groups: a Resistance Training Control Group (RTCG) composed of 10 players that did not have muscular imbalances and a Resistance Training Experimental Group (RTEG) composed of 14 players that had muscular imbalances. All players followed a resistance training program for six weeks, two times per week, during the transition period. The program of individualized strength training consisted of two parts. The first part, which was identical in terms of the choice of training loads, was intended for both training groups and contained two series of exercises including upper and lower body exercises. The second part of the program was intended only for RTEG and consisted of two additional series for the groups of muscles that had identified unilateral and bilateral differences. The applied program showed various directions in the isokinetic profile of changes. In the case of RTCG, the adaptations related mainly to the quadriceps muscle (the peak torque (PT) change for the dominant leg was statistically significant (p < 0.05)). There were statistically significant changes in RTEG (p < 0.05) related to PT for the hamstrings in both legs, which in turn resulted in an increase in the conventional hamstring/quadriceps ratio (H/Q). It is interesting that the statistically significant (p < 0.05) changes were noted only for the dominant leg. No statistically significant changes in bilateral differences (BD) were noted in either group. These results indicate that individualized resistance training programs could provide additional benefits to traditional strength training protocols to improve muscular imbalances in post-adolescent soccer players. PMID:26630271

Relationship between physical fitness at the end of pre-season and the in-season game performance in Japanese female professional baseball players.

PubMed

Watanabe, Yuya; Yamada, Yosuke; Yoshida, Tsukasa; Matsui, Tomoyuki; Seo, Kazuya; Azuma, Yoshikazu; Hiramoto, Machiko; Miura, Yuichiro; Fukushima, Hideaki; Shimazu, Akito; Eto, Toshiaki; Saotome, Homare; Kida, Noriyuki; Morihara, Toru

2017-10-30

This study examined anthropometric and fitness profiles of Japanese female professional baseball players and investigated the relationship between players' physical fitness and in-season game performance. Fifty-seven players who were registered in the Japan Women's Baseball League (JWBL) participated. Height, weight, grip strength, back strength, knee-extension and -flexion strength, hamstring extensibility, vertical jump height, and horizontal jump distance were measured at pre-season (February and March) in 2013. Game performance during the 2013 season (March to November) was obtained from official JWBL statistics. Vertical jump height showed significant positive correlations with individual performance records [e.g., total bases (r = 0.551), slugging percentage (r = 0.459), and stolen bases (r = 0.442)]. Similar relationships were observed between horizontal jump distance and performance statistics in most cases. In contrast, grip, back, and lower-limb strength, and hamstring extensibility were not significantly correlated with game performance. Stepwise regression analysis selected vertical jump height as an independent variable, significantly correlating with several game performance measures (e.g., total bases: adjusted R = 0.257). Also, vertical jump height and body mass index were identified as independent variables significantly associated with stolen bases (adjusted R = 0.251). Maximal jump performance, rather than simple isometric muscle strength or flexibility, is a good performance test that can be used at the end of pre-season to predict in-season batting and stolen base performance. Our findings demonstrate the importance of constructing pre-season training programs to enhance lower-limb muscular power that is linked to successful in-season performance in female baseball players.

A retrospective study on anthropometrical, physical fitness, and motor coordination characteristics that influence dropout, contract status, and first-team playing time in high-level soccer players aged eight to eighteen years.

PubMed

Deprez, Dieter N; Fransen, Job; Lenoir, Matthieu; Philippaerts, Renaat M; Vaeyens, Roel

2015-06-01

The goal of this article was twofold, and a 2-study approach was conducted. The first study aimed to expose the anthropometrical, physical performance, and motor coordination characteristics that influence dropout from a high-level soccer training program in players aged 8-16 years. The mixed-longitudinal sample included 388 Belgian youth soccer players who were assigned to either a "club group" or a "dropout group." In the second study, cross-sectional data of anthropometry, physical performance, and motor coordination were retrospectively explored to investigate which characteristics influence future contract status (contract vs. no contract group) and first-team playing time for 72 high-level youth soccer players (mean age = 16.2 years). Generally, club players outperformed their dropout peers for motor coordination, soccer-specific aerobic endurance, and speed. Anthropometry and estimated maturity status did not discriminate between club and dropout players. Contract players jumped further (p = 0.011) and had faster times for a 5-m sprint (p = 0.041) than no contract players. The following prediction equation explains 16.7% of the variance in future playing minutes in adolescent youth male soccer players: -2,869.3 + 14.6 × standing broad jump. Practitioners should include the evaluation of motor coordination, aerobic endurance, and speed performances to distinguish high-level soccer players further succeeding a talent development program and future dropout players, between 8 and 16 years. From the age of 16 years, measures of explosivity are supportive when selecting players into a future professional soccer career.

Match analysis of U9 and U10 english premier league academy soccer players using a global positioning system: relevance for talent identification and development.

PubMed

Goto, Heita; Morris, John G; Nevill, Mary E

2015-04-01

The purpose of this study was to examine the match activity profile of U9 and U10 elite soccer players and to establish if there were any differences between players who were subsequently retained or released by their clubs. Such information should prove valuable in the design of training programs for these very young players and in the talent identification and development process. A Global Positioning System was used to analyze 2-4 interacademy 6-a-side matches of English Premier League Academy players (U9: N = 22 and U10: N = 12) who trained 3 times a week (4.5 hours). Speed zones were created based on 5 and 10-m sprint times, and an independent sample t-test was employed for a statistical analysis. Both squads covered ∼4,000 m in total or ∼4,700 m·h during a match (p = NS between squads), with the U10 squad tending to cover a greater distance at moderate (p = 0.10) and high speeds (p = 0.08) than the U9 squad. Retained group covered a greater distance than released group (retained vs. released: 4,478 ± 513 m vs. 4,091 ± 462 m, p < 0.05) during a match and covered a greater distance during low-speed running in absolute (1,226 ± 259 m vs. 1,005 ± 221 m, p < 0.05) and relative (1,325 ± 235 m·h vs. 1,132 ± 210 m·h, p < 0.05) terms. Thus, U9 and U10 players cover over 4000 m in match play, and those players who are retained by academies cover a greater distance in total and at low speeds (2.1-3.1 m·s). This information may support the preparation of squad training programs and the talent identification and development process.

An intensive combined training program modulates physical, physiological, biomotoric, and technical parameters in women basketball players.

PubMed

Kilinç, Fatih

2008-11-01

The purpose of this study was the investigation of the effects of an intensive combined training program based on the pretest scores of a university women's basketball team on their physical, physiological, biomotoric, and technical features. Twenty-four university volunteers were equally divided into two groups: an experiment group (intensive combined training group) and a control (technical training) group. The 10-week intensive combined training program was performed on the experiment group according to their pretest outcomes. Before and at the end of each period of training, which was scheduled four times a week, the physical, physiological, biomotoric, and technical performance of each subject were determined. With respect to the pre- and posttest measurements, the basketball group showed significant differences (p < 0.05) in girth measurements (shoulder, waist, hip, arm, thigh, and calf), in skinfold measurements (percent body fat), in physiological measurements (vital capacity and forced vital capacity), in biomotoric tests (right-left hand grip, dynamic and countermovement jump, sit-up, push-up, 1500-m endurance), and in technique tests (free and inside shooting). It can be concluded that a 10-week intensive combined training program performed on university women basketball players had a significant effect on improving their physical, physiological, biomotoric, and technical features. It proved to be highly recommendable for female basketball players who are preparing for short-term tournaments; the basketball group in this study won a championship.

Prototyping Tool for Web-Based Multiuser Online Role-Playing Game

NASA Astrophysics Data System (ADS)

Okamoto, Shusuke; Kamada, Masaru; Yonekura, Tatsuhiro

This letter proposes a prototyping tool for Web-based Multiuser Online Role-Playing Game (MORPG). The design goal is to make this tool simple and powerful. The tool is comprised of a GUI editor, a translator and a runtime environment. The GUI editor is used to edit state-transition diagrams, each of which defines the behavior of the fictional characters. The state-transition diagrams are translated into C program codes, which plays the role of a game engine in RPG system. The runtime environment includes PHP, JavaScript with Ajax and HTML. So the prototype system can be played on the usual Web browser, such as Fire-fox, Safari and IE. On a click or key press by a player, the Web browser sends it to the Web server to reflect its consequence on the screens which other players are looking at. Prospected users of this tool include programming novices and schoolchildren. The knowledge or skill of any specific programming languages is not required to create state-transition diagrams. Its structure is not only suitable for the definition of a character behavior but also intuitive to help novices understand. Therefore, the users can easily create Web-based MORPG system with the tool.

Computer Programming Games and Gender Oriented Cultural Forms

NASA Astrophysics Data System (ADS)

AlSulaiman, Sarah Abdulmalik

I present the design and evaluation of two games designed to help elementary and middle school students learn computer programming concepts. The first game was designed to be "gender neutral", aligning with might be described as a consensus opinion on best practices for computational learning environments. The second game, based on the cultural form of dress up dolls was deliberately designed to appeal to females. I recruited 70 participants in an international two-phase study to investigate the relationship between games, gender, attitudes towards computer programming, and learning. My findings suggest that while the two games were equally effective in terms of learning outcomes, I saw differences in motivation between players of the two games. Specifically, participants who reported a preference for female- oriented games were more motivated to learn about computer programming when they played a game that they perceived as designed for females. In addition, I describe how the two games seemed to encourage different types of social activity between players in a classroom setting. Based on these results, I reflect on the strategy of exclusively designing games and activities as "gender neutral", and suggest that employing cultural forms, including gendered ones, may help create a more productive experience for learners.

Differential Learning as a Key Training Approach to Improve Creative and Tactical Behavior in Soccer.

PubMed

Santos, Sara; Coutinho, Diogo; Gonçalves, Bruno; Schöllhorn, Wolfgang; Sampaio, Jaime; Leite, Nuno

2018-03-01

The aim of this study was to identify the effects of a differential-learning program, embedded in small-sided games, on the creative and tactical behavior of youth soccer players. Forty players from under-13 (U13) and under-15 (U15) were allocated into control and experimental groups and were tested using a randomized pretest to posttest design using small-sided games situations. The experimental group participated in a 5-month differential-learning program embodied in small-sided games situations, while the control group participated in a typical small-sided games training program. In-game creativity was assessed through notational analyses of the creative components, and the players' positional data were used to compute tactical-derived variables. The findings suggested that differential learning facilitated the development of creative components, mainly concerning attempts (U13, small; U15, small), versatility (U13, moderate; U15, small), and originality (U13, unclear; U15, small) of players' actions. Likewise, the differential-learning approach provided a decrease in fails during the game in both experimental groups (moderate). Moreover, differential learning seemed to favor regularity in pitch-positioning behavior for the distance between players' dyads (U13, small; U15, small), the distance to the team target (U13, moderate; U15, small), and the distance to the opponent target (U13, moderate; U15, small). The differential-learning program stressed creative and positional behavior in both age groups with a distinct magnitude of effects, with the U13 players demonstrating higher improvements over the U15 players. Overall, these findings confirmed that the technical variability promoted by differential learning nurtures regularity of positioning behavior.

Measuring Responsible Gambling amongst Players: Development of the Positive Play Scale

PubMed Central

Wood, Richard T. A.; Wohl, Michael J. A.; Tabri, Nassim; Philander, Kahlil

2017-01-01

The modern gambling industry has, by-in-large, assumed a duty of care to minimize the risks associated with gambling, which has manifested in responsible gambling (RG) programming (e.g., educating players about the odds of success). The current study fills a void in gambling operators, regulators, and researchers ability to measure RG beliefs and behavior in their player-base, with the development and validation of the Positive Play Scale (PPS). In Study 1, we reviewed the literature and consulted 30 players as well as 10 RG experts to help generate a definition of RG beliefs and behavior that helped guide item generation. In Study 2, regular players (N = 1,551) of a Canadian provincial gambling operator completed a positive play survey. Four components from a principal components analysis (PCA) were extracted: Honesty and Control, Pre-commitment, Personal Responsibility, and Gambling Literacy. The PPS subscales were either not associated with gambling frequency or had small-to-moderate negative relationships with frequency of play for games most often associated with disordered gambling (e.g., electronic games). In Study 3 (N = 413), the factor structure of the PPS was confirmed and refined in a new sample of players. Moreover, a 1-month follow-up session demonstrated that the PPS has high test-retest reliability. The PPS is the first validated scale that reliably assesses the extent to which a consumer base has positive beliefs about gambling and gambles in a positive manner. The PPS can be used by the gambling industry to objectively assess the efficacy of their RG strategy, pinpoint specific areas for future focus, as well as examine the utility of new RG initiatives that aim to promote healthy patterns of gambling consumption. Furthermore, by examining the PPS scores for different player segments (e.g., sex, age, games played) it becomes possible to tailor RG strategy to the needs of specific players. In this way, RG strategy can be optimized by focusing resources where they will be most effective. PMID:28280472

NIM: A Game-Playing Program. Artificial Intelligence Memo Number 254.

ERIC Educational Resources Information Center

Papert, Seymour; Solomon, Cynthia

Students learned to plan and write complex computer programs by writing a program for playing NIM, a game in which two players alternatively remove one, two, or three sticks from an original pile of 21, with the player taking the last one being the winner. The primary teaching purpose was to develop the idea that a final goal--i.e., winning--could…

Interval-valued intuitionistic fuzzy matrix games based on Archimedean t-conorm and t-norm

NASA Astrophysics Data System (ADS)

Xia, Meimei

2018-04-01

Fuzzy game theory has been applied in many decision-making problems. The matrix game with interval-valued intuitionistic fuzzy numbers (IVIFNs) is investigated based on Archimedean t-conorm and t-norm. The existing matrix games with IVIFNs are all based on Algebraic t-conorm and t-norm, which are special cases of Archimedean t-conorm and t-norm. In this paper, the intuitionistic fuzzy aggregation operators based on Archimedean t-conorm and t-norm are employed to aggregate the payoffs of players. To derive the solution of the matrix game with IVIFNs, several mathematical programming models are developed based on Archimedean t-conorm and t-norm. The proposed models can be transformed into a pair of primal-dual linear programming models, based on which, the solution of the matrix game with IVIFNs is obtained. It is proved that the theorems being valid in the exiting matrix game with IVIFNs are still true when the general aggregation operator is used in the proposed matrix game with IVIFNs. The proposed method is an extension of the existing ones and can provide more choices for players. An example is given to illustrate the validity and the applicability of the proposed method.

Effects of the Skills4Genius sports-based training program in creative behavior.

PubMed

Santos, Sara; Jiménez, Sergio; Sampaio, Jaime; Leite, Nuno

2017-01-01

Team Sports has been suggested as a suitable environment to investigate creative behavior. This study's purpose was two-fold: first, it intended to identify the effects of the Skills4Genius sports-bases training program in thinking, motor, and in-game creative behavior in team sports. Second, it aimed to investigate the relationship between creative thinking and in-game creativity. Forty children from primary school were allocated into control (n = 18, age: 9.2±0.4) and experimental (n = 22, age: 9.5±0.7) groups. The experimental group participated in a five-month training program involving either creative thinking, diversification, physical literacy, and nonlinear pedagogy approaches (Skills4Genius). Variables in the study included: a) creative thinking; b) motor performance (vertical jump, speed, and agility); c) in-game individual creative behavior (attempts, fluency, and versatility); and d) in-game collective behavior (positional regularity). The results suggested that the Skills4Genius program fostered creative thinking, agility, and speed performance. Moreover, it stretched the in-game individual creative behavior mainly through the improvement of the attempts and versatility of the player's actions. Lastly, it nurtured a better learning of the tactical principles, whereas the children were more coordinated with their teammates' and opponents' positioning. Additionally, this study presents a positive correlation linking creative thinking and in-game creative performance. These findings highlighted that creativity is facilitated while players become more thinking and game-skilled. Coaches and educators may apply this functional environment to inspire children's disposition to move outside the box and trigger a creative spark in team sports players. Notwithstanding, the sports environment is ideally suited for fostering creative behavior, a higher-order disposition that will go on to differentiate the everyday life of a child.

Effects of Two Different Volume-Equated Weekly Distributed Short-Term Plyometric Training Programs on Futsal Players' Physical Performance.

PubMed

Yanci, Javier; Castillo, Daniel; Iturricastillo, Aitor; Ayarra, Rubén; Nakamura, Fábio Y

2017-07-01

Yanci, J, Castillo, D, Iturricastillo, A, Ayarra, R, and Nakamura, FY. Effects of two different volume-equated weekly distributed short-term plyometric training programs on futsal players' physical performance. J Strength Cond Res 31(7): 1787-1794, 2017-The aim was to analyze the effect of 2 different plyometric training programs (i.e., 1 vs. 2 sessions per week, same total weekly volume) on physical performance in futsal players. Forty-four futsal players were divided into 3 training groups differing in weekly plyometric training load: the 2 days per week plyometric training group (PT2D, n = 15), the 1 day per week plyometric training group (PT1D, n = 12), and the control group (CG, n = 12) which did not perform plyometric training. The results of this study showed that in-season futsal training per se was capable of improving repeat sprint ability (RSA) (effect size [ES] = -0.59 to -1.53). However, while change of direction ability (CODA) was maintained during the training period (ES = 0.00), 15-m sprint (ES = 0.73), and vertical jump (VJ) performance (ES = -0.30 to -1.37) were significantly impaired. By contrast, PT2D and PT1D plyometric training were effective in improving futsal players' 15-m sprint (ES = -0.64 to -1.00), CODA (ES = -1.83 to -5.50), and horizontal jump (ES = 0.33-0.64) performance. Nonetheless, all groups (i.e., PT2D, PT1D, and CG) presented a reduction in VJ performance (ES = -0.04 to -1.37). Regarding RSA performance, PT1D showed a similar improvement compared with CG (ES = -0.65 to -1.53) after the training intervention, whereas PT2D did not show significant change (ES = -0.04 to -0.38). These results may have considerable practical relevance for the optimal design of plyometric training programs for futsal players, given that a 1-day-per-week plyometric training program is more efficient than a 2-day-per-week plyometric training program to improve the futsal players' physical performance.

The Boys and Girls of Summer: Baseball Theme Programming Tips To Catch Young Readers.

ERIC Educational Resources Information Center

Kaplan, Paul

1999-01-01

Offers suggestions for library programs with a baseball theme, including tying into hobbies such as collecting baseball cards; a young peoples book discussion; trivia contests using different reference sources; letter writing to favorite players; bibliographies and displays; hosting former players; women in baseball; and the Negro Leagues. (LRW)

78 FR 39691 - Closed Captioning of Internet Protocol-Delivered Video Programming: Implementation of the Twenty...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-02

... captioning synchronization requirements for covered apparatus, and on how DVD and Blu-ray players can fulfill... captioning capabilities of certain apparatus on which consumers view video programming. DATES: Comments are... synchronization requirements for covered apparatus, and on how DVD and Blu-ray players can fulfill the closed...

A survey on adaptive engine technology for serious games

NASA Astrophysics Data System (ADS)

Rasim, Langi, Armein Z. R.; Munir, Rosmansyah, Yusep

2016-02-01

Serious Games has become a priceless tool in learning because it can simulate abstract concept to appear more realistic. The problem faced is that the players have different ability in playing the games. This causes the players to become frustrated if the game is too difficult or to get bored if it is too easy. Serious games have non-player character (NPC) in it. The NPC should be able to adapt to the players in such a way so that the players can feel comfortable in playing the games. Because of that, serious games development must involve an adaptive engine, which is by applying a learning machine that can adapt to different players. The development of adaptive engine can be viewed in terms of the frameworks and the algorithms. Frameworks include rules based, plan based, organization description based, proficiency of player based, and learning style and cognitive state based. Algorithms include agents based and non-agent based

Prediction of Lateral Ankle Sprains in Football Players Based on Clinical Tests and Body Mass Index.

PubMed

Gribble, Phillip A; Terada, Masafumi; Beard, Megan Q; Kosik, Kyle B; Lepley, Adam S; McCann, Ryan S; Pietrosimone, Brian G; Thomas, Abbey C

2016-02-01

The lateral ankle sprain (LAS) is the most common injury suffered in sports, especially in football. While suggested in some studies, a predictive role of clinical tests for LAS has not been established. To determine which clinical tests, focused on potentially modifiable factors of movement patterns and body mass index (BMI), could best demonstrate risk of LAS among high school and collegiate football players. Case-control study; Level of evidence, 3. A total of 539 high school and collegiate football players were evaluated during the preseason with the Star Excursion Balance Test (SEBT) and Functional Movement Screen as well as BMI. Results were compared between players who did and did not suffer an LAS during the season. Logistic regression analyses and calculated odds ratios were used to determine which measures predicted risk of LAS. The LAS group performed worse on the SEBT-anterior reaching direction (SEBT-ANT) and had higher BMI as compared with the noninjured group (P < .001). The strongest prediction models corresponded with the SEBT-ANT. Low performance on the SEBT-ANT predicted a risk of LAS in football players. BMI was also significantly higher in football players who sustained an LAS. Identifying clinical tools for successful LAS injury risk prediction will be a critical step toward the creation of effective prevention programs to reduce risk of sustaining an LAS during participation in football. © 2015 The Author(s).

Epidemiology of Time-Loss Injuries in Senior and under-18 Portuguese Male Rugby Players

PubMed Central

Cruz-Ferreira, Antonio Miguel; Cruz-Ferreira, Eduardo Miguel; Ribeiro, Pedro Barbosa; Santiago, Luiz Miguel; Taborda-Barata, Luis

2018-01-01

Abstract Rugby union has one of the highest injury incidence rates in team sports, however, most of the available data focus on the epidemiology of injuries in countries where rugby is popular. We aimed to report the incidence rate and relevant epidemiological aspects of injuries occurred in a group of Portuguese male rugby players. A prospective cohort study was conducted with a group of 45 senior and 32 under-18 male players (total of 77 players). Outcome measures included injury incidence, position, type, location and severity of injuries. The match injury incidence for all players was 55.84 per 1000 player match-hours (66.66 for seniors, 42.85 for under-18), while mean time-loss for injury was 20.79 days. No statistical differences were found between groups. Lower limb injuries accounted for 60.5% of all injuries, while joint/ligament injuries were the most prevalent type. Contact events were responsible for 65.1% of injuries. Despite the limitations, the obtained data are consistent with the literature. Time-loss injuries seem highly prevalent in rugby union and the incidence rates found in this Portuguese-based study were lower than the reported for international and senior men’s professional rugby union, but higher than those occurring in community rugby in tier-1 countries. The authors believe these data reinforce the need to develop and implement effective injury surveillance and prevention programs. PMID:29922379

Effect of Exercise Program Speed, Agility, and Quickness (SAQ) in Improving Speed, Agility, and Acceleration

NASA Astrophysics Data System (ADS)

Azmi, K.; Kusnanik, N. W.

2018-01-01

This study aimed to analyze the effect of speed, agility and quickness training program to increase in speed, agility and acceleration. This study was conducted at 26 soccer players and divided into 2 groups with 13 players each group. Group 1 was given SAQ training program, and Group 2 conventional training program for 8 weeks. This study used a quantitative approach with quasi-experimental method. The design of this study used a matching-only design. Data was collected by testing 30-meter sprint (speed), agility t-test (agility), and run 10 meters (acceleration) during the pretest and posttest. Furthermore, the data was analyzed using paired sample t-test and independent t-test. The results showed: that there was a significant effect of speed, agility and quickness training program in improving in speed, agility and acceleration. In summary, it can be concluded that the speed, agility and quickness training program can improve the speed, agility and acceleration of the soccer players.

Effectiveness of a tailored neck training program on neck strength, movement, and fatigue in under-19 male rugby players: a randomized controlled pilot study.

PubMed

Barrett, Matthew D; McLoughlin, Terence F; Gallagher, Kieran R; Gatherer, Don; Parratt, Michael Tr; Perera, Jonathan R; Briggs, Tim Wr

2015-01-01

To investigate the effect of a tailored neck muscle conditioning program on neck muscle strength, neck muscle fatigue, and range of neck movement in 16-18-year-old male rugby players. Thirty-four male rugby players were divided into forward and back playing positions and randomized within these groups. Seventeen players were randomly assigned to each group. The test group was given a tailored 6-week exercise regime based on their baseline measurements to be performed three times a week in addition to their normal training and playing. The control group trained and played as normal. The outcome measures used were cervical spine range of movement, neck strength, and neck muscle fatigability. There were no clinically relevant statistically significant differences between the two groups. Trends identified between the two groups suggest that a tailored neck exercise program increases neck strength, particularly neck extension, and increases resistance to fatigue, as well as influencing right- and left-sided neck muscle balance. A reduction in range of movement was also demonstrated in the test group. There was a great deal of variability in range of movement and strength within this age group. No previously undiagnosed neck conditions were detected, and there were no adverse events reported. This study has shown that neck strength, range of movement, and susceptibility of the neck muscles to fatigue can be influenced using a focused neck training regime. It forms an important basis for a larger, multicenter study to ensure the neck is given due attention in rugby training and receives the same focus of conditioning as other parts of the body.

Perceived motivational factors for female football players during rehabilitation after sports injury - a qualitative interview study.

PubMed

Hildingsson, Malin; Fitzgerald, Ulrika Tranaeus; Alricsson, Marie

2018-04-01

Compliance with a rehabilitation program is significant among athletes following a sports injury. It is also one of the main factors that influence the rehabilitation process; moreover, the outcome is also influenced by the athlete's motivation. It is primarily an autonomous motivation, resulting in rehabilitation adherence. The aim of this study was to investigate the perceived motivation of female football players during rehabilitation after a sports injury and the extent to which these motivating factors were autonomous. Qualitative interviews, based on a semistructured interview guide with injured female football players undergoing rehabilitation, were analyzed using content analysis. The motivational factors that were described were their set goals, social support as well as external and internal pressures during rehabilitation. The perceived autonomy varied somewhat but overall, they experienced external motivation; therefore, the behavior was not entirely self-determined. Results are expected to provide a better understanding of women football players' motivation in relation to their rehabilitation; hence, physiotherapists and coaches who are part of the rehabilitation process can contribute by increasing the autonomous motivation, thus, improving the compliance and outcome of the rehabilitation.

Implementation of system dynamic simulation method to optimize profit in supply chain network of vegetable product

NASA Astrophysics Data System (ADS)

Tama, I. P.; Akbar, Z.; Eunike, A.

2018-04-01

Vegetables are categorized as a perishable product, which is a product with short lifespan thus requires proper handling and planning to reduce losses caused by the short lifespan. In order to reduce the losses, coordination among the players in the supply chain is required. On the other hand, the decision in the supply chain of vegetables and other farming products in the traditional market of developing country is independent among the players. This research is conducted by using System Dynamic Simulation method to develop model and scenario by coordinating the supply quantity amongst players in the supply chain. The scenarios are developed based on newsboy inventory model. This study aims to compare scenarios combining tiers involved in coordination program. The result shows that coordination in supply chain increases total supply chain profit, although there will always be players who experienced decrements in profit. The scenario of coordination among the farmer, the distributor, and the wholesaler resulted in the highest increase in total supply chain profit compared to other coordination scenarios, with an increased value of 10.49%.

Measurement of talent in team handball: the questionable use of motor and physical tests.

PubMed

Lidor, Ronnie; Falk, Bareket; Arnon, Michal; Cohen, Yoram; Segal, Gil; Lander, Yael

2005-05-01

Testing for selection is one of the most important fundamentals in any multistep sport program. In most ball games, coaches assess motor, physical, and technical skills on a regular basis in early stages of talent identification and development. However, selection processes are complex, are often unstructured, and lack clear-cut theory-based knowledge. For example, little is known about the relevance of the testing process to the final selection of the young prospects. The purpose of this study was to identify motor, physical, and skill variables that could provide coaches with relevant information in the selection process of young team handball players. In total, 405 players (12-13 years of age at the beginning of the testing period) were recommended by their coaches to undergo a battery of tests prior to selection to the Junior National Team. This number is the sum of all players participating in the different phases of the program. However, not all of them took part in each testing phase. The battery included physical measurements (height and weight), a 4 x 10-m running test, explosive power tests (medicine ball throw and standing long jump), speed tests (a 20-m sprint from a standing position and a 20-m sprint with a flying start), and a slalom dribbling test. Comparisons between those players eventually selected to the Junior National Team 2-3 years later with those not selected demonstrated that only the skill test served as a good indicator. In all other measurements, a wide overlap could be seen between the results of the selected and nonselected players. It is suggested that future studies investigate the usefulness of tests reflecting more specific physical ability and cognitive characteristics.

What is the effect of a shoulder-strengthening program to prevent shoulder pain among junior female team handball players?

PubMed Central

Sommervold, Maria; Østerås, Håvard

2017-01-01

Background Excessively high stresses are applied to the shoulder joint of handball players, mainly caused by overhead throwing. Shoulder pain is a significant problem among junior female team handball players and both male and female top-level team handball players in Norway. Method A randomized selection was performed among the best female junior teams (J 16) in the Trøndelag region of Norway in the 2014–2015 season. Three teams were randomized to the intervention group and three teams to the control group. Players in the intervention group (n=53) participated in a seven-month, three-times-a-week shoulder-muscle strength-training program, while those in the control group (n=53) participated in a comparable handball training, but did not conduct any specific strength training during the season. Results A strength-training program had no effect on the prevention of shoulder pain. Overall, the players reported shoulder pain, but graded the pain low on visual analog scale (VAS). Both the intervention group and the control group reported pain under 1 on VAS at baseline and posttest, and there was no significant difference within or between the groups when it came to the intensity of pain reported on VAS. A significant difference (p<0.048) was found between the groups on the sport-specific part of the quick-Disability of the Arm, Shoulder and Hand (DASH) form, but it did not fulfill the minimal demand to change and the players scored it low, something that indicates little functional problems when it comes to team handball. The intervention group was significantly stronger (p<0.008) on the push-ups test compared to the control group on the posttest. The intervention group increased the number of push-ups from 3.1 to 6.4, while the control group went from 2.3 to 3.6. Aside from this, there were no significant differences in between the groups. Conclusion A shoulder-strengthening program had no effect on the prevention of shoulder pain among junior female team handball players. PMID:28435335

What is the effect of a shoulder-strengthening program to prevent shoulder pain among junior female team handball players?

PubMed

Sommervold, Maria; Østerås, Håvard

2017-01-01

Excessively high stresses are applied to the shoulder joint of handball players, mainly caused by overhead throwing. Shoulder pain is a significant problem among junior female team handball players and both male and female top-level team handball players in Norway. A randomized selection was performed among the best female junior teams (J 16) in the Trøndelag region of Norway in the 2014-2015 season. Three teams were randomized to the intervention group and three teams to the control group. Players in the intervention group (n=53) participated in a seven-month, three-times-a-week shoulder-muscle strength-training program, while those in the control group (n=53) participated in a comparable handball training, but did not conduct any specific strength training during the season. A strength-training program had no effect on the prevention of shoulder pain. Overall, the players reported shoulder pain, but graded the pain low on visual analog scale (VAS). Both the intervention group and the control group reported pain under 1 on VAS at baseline and posttest, and there was no significant difference within or between the groups when it came to the intensity of pain reported on VAS. A significant difference ( p <0.048) was found between the groups on the sport-specific part of the quick-Disability of the Arm, Shoulder and Hand (DASH) form, but it did not fulfill the minimal demand to change and the players scored it low, something that indicates little functional problems when it comes to team handball. The intervention group was significantly stronger ( p <0.008) on the push-ups test compared to the control group on the posttest. The intervention group increased the number of push-ups from 3.1 to 6.4, while the control group went from 2.3 to 3.6. Aside from this, there were no significant differences in between the groups. A shoulder-strengthening program had no effect on the prevention of shoulder pain among junior female team handball players.

Asymptomatic Elite Adolescent Tennis Players' Signs of Tendinosis in Their Dominant Shoulder Compared With Their Nondominant Shoulder

PubMed Central

Johansson, Fredrik R.; Skillgate, Eva; Adolfsson, Anders; Jenner, Göran; DeBri, Edin; Swärdh, Leif; Cools, Ann M.

2015-01-01

Context Tennis is an asymmetric overhead sport with specific muscle-activation patterns, especially eccentrically in the rotator cuff. Magnetic resonance imaging (MRI) findings in asymptomatic adolescent elite tennis players have not previously been reported. Objective The first aim of the study was to describe MRI findings regarding adaptations or abnormalities, as well as muscle cross-sectional area (CSA), of the rotator cuff. The second aim of the study was to investigate the rotator cuff based on the interpretation of the MRI scans as normal versus abnormal, with the subdivision based on the grade of tendinosis, and its association with eccentric rotator cuff strength in the dominant arm (DA) of the asymptomatic elite adolescent tennis player. Setting Testing environment at the radiology department of Medicinsk Röntgen AB. Patients or Other Participants Thirty-five asymptomatic elite tennis players (age = 17.4 ± 2.7 years) were selected based on ranking and exposure time. Intervention(s) We assessed MRI scans and measured the CSA of the rotator cuff muscle. The non-DA (NDA) was used as a control. In addition, eccentric testing of the external rotators of the DA was performed with a handheld dynamometer. Results The DA and NDA displayed different frequencies of infraspinatus tendinosis (grade 1 changes) (P < .05). Rotator cuff measurements revealed larger infraspinatus and teres minor CSA (P < .05) in the DA than in the NDA. Mean eccentric external-rotation strength in the DA stratified by normal tendon and tendinosis was not different between groups (P = .723). Conclusions Asymptomatic adolescent elite tennis players demonstrated infraspinatus tendinosis more frequently in the DA than in the NDA. Clinicians must recognize these tendon changes in order to modify conditioning and performance programs appropriately. PMID:26651279

School dropout prevention: what arts-based community and out-of-school-time programs can contribute.

PubMed

Charmaraman, Linda; Hall, Georgia

2011-01-01

Out-of-school-time programs, especially arts-based programs, can be critical players in a community's efforts to prevent school dropout. This research review suggests the following approaches for arts-based programs: (1) recruitment and retention of target populations with multiple risk factors; (2) long-term skill development that engages youth behaviorally, emotionally, and academically rather than a drop-in culture; (3) an emphasis on the critical ingredient of real-world applications through performance; (4) staff development and mentoring; (5) a strategic community-level plan for dropout prevention; (6) and program content reframed toward competencies that underlie better school performance and prosocial behavior, such as communication, initiative, problem solving, motivation, and self-efficacy. Copyright © 2011 Wiley Periodicals, Inc., A Wiley Company.

Positional Role Differences in the Aerobic and Anaerobic Power of Elite Basketball Players.

PubMed

Pojskić, Haris; Šeparović, Vlatko; Užičanin, Edin; Muratović, Melika; Mačković, Samir

2015-12-22

The aim of the present study was to compare the aerobic and anaerobic power and capacity of elite male basketball players who played multiple positions. Fifty-five healthy players were divided into the following three different subsamples according to their positional role: guards (n = 22), forwards (n = 19) and centers (n = 14). The following three tests were applied to estimate their aerobic and anaerobic power and capacities: the countermovement jump (CMJ), a multistage shuttle run test and the Running-based Anaerobic Sprint Test (RAST). The obtained data were used to calculate the players' aerobic and anaerobic power and capacities. To determine the possible differences between the subjects considering their different positions on the court, one-way analysis of variance (ANOVA) with the Bonferroni post-hoc test for multiple comparisons was used. The results showed that there was a significant difference between the different groups of players in eleven out of sixteen measured variables. Guards and forwards exhibited greater aerobic and relative values of anaerobic power, allowing shorter recovery times and the ability to repeat high intensity, basketball-specific activities. Centers presented greater values of absolute anaerobic power and capacities, permitting greater force production during discrete tasks. Coaches can use these data to create more individualized strength and conditioning programs for different positional roles.

Tennis injuries: prevention and treatment. A review.

PubMed

Kulund, D N; McCue, F C; Rockwell, D A; Gieck, J H

1979-01-01

When players are engaged in the sport of tennis, injuries may occur to the eyes, in the neck, to the shoulder and back, arm and elbow, wrist and hand, and feet. The key to prevention and treatment of these injuries is good coaching and a formal stretching and strengthening program. The drooped "tennis shoulder" of professionals and senior tennis players is a natural response to heavy use. Shoulder elevating exercises are useful when soreness is associated. The treatment of tennis elbow includes wrist extensor stretching, isometrics, and light weightlifting. When a player follows this program, injections or counterforce braces are rarely needed. It is important for the player to bring his racket to the examination so that his stroke mechanics and grip can be checked. Wrist soreness in a tennis player may denote a hamate hook fracture. Special radiographic views are needed to discern the fracture and it is treated with a short arm cast and little finger extension splint. Nonunion of a hamate hook requires excision. The calf pain prodrome of "tennis leg" requires rest and then a stretching program. Tennis shoes should have rolled heels and large toe boxes with reinforced toe bumpers. The physician may have to fashion soft inserts for the tennis shoes; arch supports may be insufficient.

"Ballistic Six" Upper-Extremity Plyometric Training for the Pediatric Volleyball Players.

PubMed

Turgut, Elif; Cinar-Medeni, Ozge; Colakoglu, Filiz F; Baltaci, Gul

2017-09-19

The Ballistic Six exercise program includes commonly used upper-body exercises, and the program is recommended for overhead throwing athletes. The purpose of the current study was to investigate the effects of a 12-week the Ballistic Six upper-extremity plyometric training program on upper-body explosive power, endurance, and reaction time in pediatric overhead athletes. Twenty-eight female pediatric volleyball players participated in the study. The participants were randomly divided into 2 study groups: an intervention group (upper-extremity plyometric training in addition to the volleyball training; n = 14) and a control group (the volleyball training only; n = 14). All the participants were assessed before and after a 12-week training program for upper-body power, strength and endurance, and reaction time. Statistical comparison was performed using an analysis of variance test. Comparisons showed that after a 12-week training program, the Ballistic Six upper-body plyometric training program resulted in more improvements in an overhead medicine ball throwing distance and a push-up performance, as well as greater improvements in the reaction time in the nonthrowing arm when compared with control training. In addition, a 12-week training program was found to be effective in achieving improvements in the reaction time in the throwing arm for both groups similarly. Compared with regular training, upper-body plyometric training resulted in additional improvements in upper-body power and strength and endurance among pediatric volleyball players. The findings of the study provide a basis for developing training protocols for pediatric volleyball players.

Soccer Injuries in Players Aged 7 to 12 Years: A Descriptive Epidemiological Study Over 2 Seasons.

PubMed

Rössler, Roland; Junge, Astrid; Chomiak, Jiri; Dvorak, Jiri; Faude, Oliver

2016-02-01

As part of a risk-management approach, sound epidemiological data are needed to develop prevention programs. A recent review on soccer injuries of players younger than 19 years concluded that prospective data concerning children are lacking. To analyze the incidence and characteristics of soccer injuries in children aged 7 to 12 years. Descriptive epidemiological study. The present survey was a prospective descriptive epidemiological study on soccer injuries over 2 seasons in the Czech Republic and Switzerland. Exposure of players during training and match play (in hours) and injury data were reported by coaches via an Internet-based registration system. Location, type, and severity of injuries were classified according to an established consensus. Injury characteristics are presented as absolute numbers and injury incidence rates (injuries per 1000 hours of soccer exposure). An injury was defined as any physical complaint sustained during a scheduled training session or match play resulting in at least 1 of the following: (1) inability to complete the current match or training session, (2) absence from subsequent training sessions or matches, and (3) injury requiring medical attention. In total, 6038 player-seasons with 395,295 hours of soccer exposure were recorded. The mean (±SD) age of the players was 9.5 ± 2.0 years, and 3.9% of the participants were girls. A total of 417 injuries were reported. Most (76.3%) injuries were located in the lower limbs, with 15.6% located in the upper limbs. Joint and ligament injuries comprised 30.5%, contusions 22.5%, muscle and tendon injuries 18.5%, and fractures and bone injuries 15.4% of all injuries; 23.7% of injuries led to more than 28 days of absence from sport participation. The overall injury incidence was 0.61 (95% CI, 0.53-0.69) injuries per 1000 hours of soccer exposure during training sessions and 4.57 (95% CI, 4.00-5.23) during match play. Injury incidence rates increased with increasing age. The observed injury incidences were lower compared with studies in youth players. Children showed a relatively high proportion of fractures and bone stress and of injuries to the upper limbs. The study provides an evidence base for injury incidence rates and injury characteristics in children's soccer. These data are the basis to develop an age-specific injury-prevention program. © 2015 The Author(s).

The usefulness and reliability of fitness testing protocols for ice hockey players: a literature review.

PubMed

Nightingale, Steven C; Miller, Stuart; Turner, Anthony

2013-06-01

Ice hockey, like most sports, uses fitness testing to assess athletes. This study reviews the current commonly used fitness testing protocols for ice hockey players, discussing their predictive values and reliability. It also discusses a range of less commonly used measures and limitations in current testing protocols. The article concludes with a proposed testing program suitable for ice hockey players.

The Effects of the Gaelic Athletic Association 15 Training Program on Neuromuscular Outcomes in Gaelic Football and Hurling Players: A Randomized Cluster Trial.

PubMed

OʼMalley, Edwenia; Murphy, John C; McCarthy Persson, Ulrik; Gissane, Conor; Blake, Catherine

2017-08-01

O'Malley, E, Murphy, JC, McCarthy Persson, U, Gissane, C, and Blake, C. The effects of the Gaelic Athletic Association 15 training program on neuromuscular outcomes in Gaelic football and hurling players: A randomized cluster trial. J Strength Cond Res 31(8): 2119-2130, 2017-Team-based neuromuscular training programs for injury prevention have been tested primarily in female and adolescent athletes in soccer, handball, and basketball with limited research in adult male field sports. This study explored whether the GAA 15, a multifaceted 8-week neuromuscular training program developed by the Gaelic Athletic Association (GAA), could improve risk factors for lower limb injury in male Gaelic footballers and hurlers. Four Gaelic sports collegiate teams were randomized into intervention or control groups. Two teams (n = 41), one football and one hurling, were allocated to the intervention, undertaking a 15 minutes program of neuromuscular training exercises at the start of team training sessions, twice weekly for 8 weeks. Two matched teams (n = 37) acted as controls, participating in usual team training. Lower extremity stability (Y-Balance test [YBT]) and jump-landing technique using the Landing Error Scoring System (LESS) were assessed preintervention and postintervention. There were moderate effect sizes in favor of the intervention for right (d = 0.59) and left (d = 0.69) composite YBT scores, with adjusted mean differences between intervention and control of 3.85 ± 0.91% and 4.34 ± 0.92% for right and left legs, respectively (p < 0.001). There was a greater reduction in the mean LESS score in favor of the intervention group after exercise training (Cohen's d = 0.72, adjusted mean difference 2.49 ± 0.54, p < 0.001). Clinically and statistically significant improvements in dynamic balance and jump-landing technique occurred in collegiate level Gaelic football and hurling players who adopted the GAA 15, when compared with usual training. These findings support application and evaluation of the GAA 15 in other player groups within the Gaelic games playing population.

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.

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

Cohesion and Trauma: An Examination of a Collegiate Women's Volleyball Team

ERIC Educational Resources Information Center

Fletcher, Teresa B.; Meyer, Barbara B.

2009-01-01

This study examined the effects of Adventure Based Counseling (i.e., a low-element challenge program) on the cohesion of a collegiate women's volleyball team. Results suggest postintervention improvements in team cohesion. The support created in the challenge experience also transferred to the players helping one another to grieve the untimely…

Telemetry and Communication IP Video Player

NASA Technical Reports Server (NTRS)

OFarrell, Zachary L.

2011-01-01

Aegis Video Player is the name of the video over IP system for the Telemetry and Communications group of the Launch Services Program. Aegis' purpose is to display video streamed over a network connection to be viewed during launches. To accomplish this task, a VLC ActiveX plug-in was used in C# to provide the basic capabilities of video streaming. The program was then customized to be used during launches. The VLC plug-in can be configured programmatically to display a single stream, but for this project multiple streams needed to be accessed. To accomplish this, an easy to use, informative menu system was added to the program to enable users to quickly switch between videos. Other features were added to make the player more useful, such as watching multiple videos and watching a video in full screen.

Increasing girls' physical activity during a short-term organized youth sport basketball program: A randomized controlled trial.

PubMed

Guagliano, Justin M; Lonsdale, Chris; Kolt, Gregory S; Rosenkranz, Richard R; George, Emma S

2015-07-01

To evaluate the short-term efficacy of coach education on basketball players' physical activity (PA) intensity during practices. Intervention effects on players' motivation were also investigated. Randomized controlled trial. This study took place over the course of a 5-day organized youth sport (OYS) basketball program in 2 sports centres in Greater Western Sydney, Australia (September, 2013). A convenience sample of 76 players and 8 coaches were recruited. Players were girls aged 9 to 12 years. Following the first 2 days of the basketball program, coaches allocated into the intervention condition attended 2 coach education sessions where strategies to increase moderate-to-vigorous physical activity (MVPA) and decrease inactivity were discussed. Each coach education session lasted approximately 2h. Compared to the control group, players in the intervention group spent a significantly higher proportion of practice time in MVPA (mean difference [MD]=14.6%; standard error [SE]=2.2%), vigorous PA (VPA; MD=12.6%; SE=1.9%), moderate PA (MD=2.0%; SE=0.5%) and a significantly lower proportion of practice time inactive (MD=-14.5%; SE=2.3%) from baseline to follow-up. There were no significant changes in motivation from baseline to follow-up in either group. Brief coach education sessions can increase MVPA and decrease inactivity without deleterious effects on players' motivation. Also, substantial increases in VPA were found, which is an important finding because VPA has been associated with health benefits, over and above benefits accrued from lower-intensity activity. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Encouraging junior community netball players to learn correct safe landing technique.

PubMed

White, Peta E; Ullah, Shahid; Donaldson, Alex; Otago, Leonie; Saunders, Natalie; Romiti, Maria; Finch, Caroline F

2012-01-01

Behavioural factors and beliefs are important determinants of the adoption of sports injury interventions. This study aimed to understand behavioural factors associated with junior community netball players' intentions to learn correct landing technique during coach-led training sessions, proposed as a means of reducing their risk of lower limb injury. Cross-sectional survey. 287 female players from 58 junior netball teams in the 2007/2008-summer competition completed a 13-item questionnaire developed from the Theory of Planned Behaviour (TPB). This assessed players' attitudes (four items), subjective norms (four), perceived behavioural control (four) and intentions (one) around the safety behaviour of learning correct landing technique at netball training. All items were rated on a seven-point bipolar scale. Cluster-adjusted logistic regression was used to assess which TPB constructs were most associated with strong intentions. Players had positive intentions and attitudes towards learning safe landing technique and perceived positive social pressure from significant others. They also perceived themselves to have considerable control over engaging (or not) in this behaviour. Players' attitudes (p<0.001) and subjective norms (p<0.001), but not perceived behavioural control (p=0.49), were associated with strong intentions to learn correct landing technique at training. Injury prevention implementation strategies aimed at maximising junior players' participation in correct landing training programs should emphasise the benefits of learning correct landing technique (i.e. change attitudes) and involve significant others and role models whom junior players admire (i.e. capitalise on social norms) in the promotion of such programs. Copyright © 2011 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Physical and physiological characteristics in male team handball players by playing position - Does age matter?

PubMed

Nikolaidis, P T; Ingebrigtsen, J; Póvoas, S C; Moss, S; Torres-Luque, G

2015-04-01

The purpose of this study was to examine the variation in physical and physiological characteristics according to playing position in adolescent and adult male team handball (TH) players. Adolescent (N.=57, aged 14.9±1.4 yr) and adult (N.=39, 26.6±5.7 yr) players were examined for anthropometric characteristics, somatotype and body composition, and performed the physical working capacity test, a force-velocity test, the Wingate anaerobic test (WAnT), sit-and-reach test, handgrip strength test, squat jump (SJ), countermovement vertical jump without (CMJ) and with arm-swing, and a 30-s Bosco test. Eccentric utilization ratio (EUR) was calculated as the ratio CMJ to SJ. In adult players, there were significant differences between wings and the other positions with regard to anthropometric and body composition parameters (body mass, -17.9% to -13.2%; height, -5.3% to -4.3%; and fat-free mass, -13.7% to -9.9%) and anaerobic power assessed by WAnT (peak power, -20.5% to -15.2%; and mean power, -20% to -14.8%); however, these characteristics did not differ significantly in adolescents, in which the only statistically significant difference was found between goalkeepers and the other positions in EUR (+8.1%). Therefore, the differences in physical and physiological characteristics between playing positions are age-dependent. As adult players in this study were taken from players competing in the top Greek league, findings could serve as a base for talent identification and development for future studies. Moreover, knowledge about positional differences might enhance the ability to make tailored position-specific training programs among adult and adolescent players in the future.

Bayesian Modeling of a Human MMORPG Player

NASA Astrophysics Data System (ADS)

Synnaeve, Gabriel; Bessière, Pierre

2011-03-01

This paper describes an application of Bayesian programming to the control of an autonomous avatar in a multiplayer role-playing game (the example is based on World of Warcraft). We model a particular task, which consists of choosing what to do and to select which target in a situation where allies and foes are present. We explain the model in Bayesian programming and show how we could learn the conditional probabilities from data gathered during human-played sessions.

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 players, justifying future efforts toward sport-specific ACL injury prevention programs.

Morphological, Physiological and Skating Performance Profiles of Male Age-Group Elite Ice Hockey Players.

PubMed

Allisse, Maxime; Sercia, Pierre; Comtois, Alain-Steve; Leone, Mario

2017-09-01

The purpose of this study was to describe the evolution of morphological, physiological and skating performance profiles of elite age-group ice hockey players based on repeated measures spread over one season. In addition, the results of fitness tests and training programs performed in off-ice conditions and their relationship with skating performance were analyzed. Eighteen high level age-group ice hockey players (13.1 ± 0.6 years) were assessed off and on-ice at the beginning and at the end of the hockey season. A third evaluation was also conducted at the beginning of the following hockey season. The players were taller, heavier, and showed bone breadths and muscle girths above the reference population of the same age. Muscular variables improved significantly during and between the two hockey seasons (p < 0.05). However, maximal aerobic power improved only during the off-season. All skating performance tests exhibited significant enhancements during the hockey season, but not during the off-season where some degradation was observed. Finally, weak observed variances (generally <20% of the explained variance) between physiological variables measured off-ice and on-ice skating performance tests indicated important gaps, both in the choice of the off-ice assessment tools as well as in training methods conventionally used. The reflection on the best way to assess and train hockey players certainly deserves to be continued.

Morphological, Physiological and Skating Performance Profiles of Male Age-Group Elite Ice Hockey Players

PubMed Central

Allisse, Maxime; Sercia, Pierre; Comtois, Alain-Steve; Leone, Mario

2017-01-01

Abstract The purpose of this study was to describe the evolution of morphological, physiological and skating performance profiles of elite age-group ice hockey players based on repeated measures spread over one season. In addition, the results of fitness tests and training programs performed in off-ice conditions and their relationship with skating performance were analyzed. Eighteen high level age-group ice hockey players (13.1 ± 0.6 years) were assessed off and on-ice at the beginning and at the end of the hockey season. A third evaluation was also conducted at the beginning of the following hockey season. The players were taller, heavier, and showed bone breadths and muscle girths above the reference population of the same age. Muscular variables improved significantly during and between the two hockey seasons (p < 0.05). However, maximal aerobic power improved only during the off-season. All skating performance tests exhibited significant enhancements during the hockey season, but not during the off-season where some degradation was observed. Finally, weak observed variances (generally <20% of the explained variance) between physiological variables measured off-ice and on-ice skating performance tests indicated important gaps, both in the choice of the off-ice assessment tools as well as in training methods conventionally used. The reflection on the best way to assess and train hockey players certainly deserves to be continued. PMID:28828080

Reasoning and Action: Implementation of a Decision-Making Program in Sport.

PubMed

Gil-Arias, Alexander; Moreno, M Perla; García-Mas, Alex; Moreno, Alberto; García-González, Luíz; Del Villar, Fernando

2016-09-20

The objective of this study was to apply a decision training programme, based on the use of video-feedback and questioning, in real game time, in order to improve decision-making in volleyball attack actions. A three-phase quasi-experimental design was implemented: Phase A (pre-test), Phase B (Intervention) and Phase C (Retention). The sample was made up of 8 female Under-16 volleyball players, who were divided into two groups: experimental group (n = 4) and control group (n = 4). The independent variable was the decision training program, which was applied for 11 weeks in a training context, more specifically in a 6x6 game situation. The player had to analyze the reasons and causes of the decision taken. The dependent variable was decision-making, which was assessed based on systematic observation, using the "Game Performance Assessment Instrument" (GPAI) (Oslin, Mitchell, & Griffin, 1998). Results showed that, after applying the decision training program, the experimental group showed a significantly higher average percentage of successful decisions than the control group F(1, 6) = 11.26; p = .015; η2 p = .652; 95% CI [056, 360]. These results highlight the need to complement the training process with cognitive tools such as video-feedback and questioning in order to improve athletes' decision-making.

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…

Preventing musculoskeletal injuries among recreational adult volleyball players: design of a randomised prospective controlled trial.

PubMed

Gouttebarge, Vincent; Zwerver, Johannes; Verhagen, Evert

2017-08-02

Both acute and overuse injuries are common among recreational volleyball players, especially finger/wrist, ankle, shoulder and knee injuries. Consequently, an intervention ('VolleyVeilig') was developed to prevent or reduce the occurrence of finger/wrist, shoulder, knee and ankle injuries among recreational volleyball players. This article describes the design of a study evaluating the effectiveness of the developed intervention on the one-season occurrence of finger/wrist, shoulder, knee and ankle injuries among recreational adult volleyball players. A randomized prospective controlled trial with a follow-up period of one volleyball season will be conducted. Participants will be healthy recreational adult volleyball players (18 years of age or older) practicing volleyball (training and/or match) at least twice a week. The intervention ('VolleyVeilig') consists of a warm-up program based on more than 50 distinct exercises (with different variations and levels). The effect of the intervention programme on the occurrence of injuries will be compared to volleyball as usual. Outcome measures will be incidence of acute injury (expressed as number of injuries per 1000 h of play) and prevalence of overuse injuries (expressed as percentage). This study will be one of the first randomized prospective controlled trials evaluating the effectiveness of an intervention on the occurrence of both acute and overuse injuries among recreational adult volleyball players. Outcome of this study could possibly lead to the nationwide implementation of the intervention in all volleyball clubs in The Netherlands, ultimately resulting in less injuries. Dutch Trial Registration NTR6202 , registered February 1st 2017. Version 3, February 2017.

The Effects of Injury Preventive Warm-Up Programs on Knee Strength Ratio in Young Male Professional Soccer Players

PubMed Central

Daneshjoo, Abdolhamid; Mokhtar, Abdul Halim; Rahnama, Nader; Yusof, Ashril

2012-01-01

Purpose We aimed to investigate the effect of FIFA 11+ (11+) and HarmoKnee injury preventive warm-up programs on conventional strength ratio (CSR), dynamic control ratio (DCR) and fast/slow speed ratio (FSR) in young male professional soccer players. These ratios are related to the risk of injury to the knee in soccer players. Methods Thirty-six players were divided into 3 groups; FIFA 11+, HarmoKnee and control (n = 12 per group). These exercises were performed 3 times per week for 2 months (24 sessions). The CSR, DCR and FSR were measured before and after the intervention. Results After training, the CSR and DCR of knee muscles in both groups were found to be lower than the published normal values (0.61, 0.72, and 0.78 during 60°.s−1, 180°.s−1 and 300°.s−1, respectively). The CSR (60°.s−1) increased by 8% and FSR in the quadriceps of the non-dominant leg by 8% in the 11+. Meanwhile, the DCR in the dominant and non-dominant legs were reduced by 40% and 30% respectively in the 11+. The CSR (60°.s−1) in the non-dominant leg showed significant differences between the 11+, HarmoKnee and control groups (p = 0.02). As for the DCR analysis between groups, there were significant differences in the non-dominant leg between both programs with the control group (p = 0.04). For FSR no significant changes were found between groups. Conclusions It can be concluded that the 11+ improved CSR and FSR, but the HarmoKnee program did not demonstrate improvement. We suggest adding more training elements to the HarmoKnee program that aimed to enhance hamstring strength (CSR, DCR and FSR). Professional soccer players have higher predisposition of getting knee injuries because hamstring to quadriceps ratio were found to be lower than the average values. It seems that the 11+ have potentials to improve CSR and FSR as well as prevent knee injuries in soccer players. PMID:23226553

Effect of High-Speed Strength Training on Physical Performance in Young Soccer Players of Different Ages.

PubMed

Rodríguez-Rosell, David; Franco-Márquez, Felipe; Mora-Custodio, Ricardo; González-Badillo, Juan José

2017-09-01

Rodríguez-Rosell, D, Franco-Márquez, F, Mora-Custodio, R, and González-Badillo, JJ. Effect of high-speed strength training on physical performance in young soccer players of different ages. J Strength Cond Res 31(9): 2498-2508, 2017-The aim of the present study was to compare the effectiveness of low-load, low-volume weight training combined with plyometrics on strength, sprint, and jump performance in soccer players of different ages. Eighty-six soccer players from the same academy were categorized into 3 groups by age (under 13 years, U13, n = 30; under 15, U15, n = 28; and under 17, U17, n = 28) and then randomly assigned into 2 subgroups: a strength training group (STG) and a control group (CG). The strength training program was performed twice a week for 6 weeks and consisted of full squats (load: 45-60% 1 repetition maximum; volume: 3 set of 8-4 repetitions), jumps, and straight line sprint exercises. After training intervention, the STGs showed significant improvements in maximal strength (7.5-54.5%; p < 0.001), jump height (5.7-12.5%; p <0.01-0.001), and sprint time (-3.7 to -1.2%; p ≤0.05-0.001), whereas no significant gains were found for any variable in the CGs. Comparison between experimental groups resulted in a greater magnitude of change for U13 compared with U15 (effect sizes [ES]: 0.10-0.53) and U17 (ES: 0.14-1.41) soccer players in most variables, whereas U15 showed higher improvements in jump and strength parameters than U17 (ES: 0.25-0.90) soccer players. Thus, although our results indicates that a combined weight training and plyometrics program may be effective in eliciting gains in strength, jump, and sprint in soccer players of different ages, the training program used appears to be generally less effective as the age of the soccer players increased. Therefore, it appears that training characteristics (mainly volume, intensity, and type of exercise) should be modified in relation to maturity status and initial strength level.

A prospective study of concussions among National Hockey League players during regular season games: the NHL-NHLPA Concussion Program.

PubMed

Benson, Brian W; Meeuwisse, Willem H; Rizos, John; Kang, Jian; Burke, Charles J

2011-05-17

In 1997, the National Hockey League (NHL) and NHL Players' Association (NHLPA) launched a concussion program to improve the understanding of this injury. We explored initial postconcussion signs, symptoms, physical examination findings and time loss (i.e., time between the injury and medical clearance by the physician to return to competitive play), experienced by male professional ice-hockey players, and assessed the utility of initial postconcussion clinical manifestations in predicting time loss among hockey players. We conducted a prospective case series of concussions over seven NHL regular seasons (1997-2004) using an inclusive cohort of players. The primary outcome was concussion and the secondary outcome was time loss. NHL team physicians documented post-concussion clinical manifestations and recorded the date when a player was medically cleared to return to play. Team physicians reported 559 concussions during regular season games. The estimated incidence was 1.8 concussions per 1000 player-hours. The most common postconcussion symptom was headache (71%). On average, time loss (in days) increased 2.25 times (95% confidence interval [CI] 1.41-3.62) for every subsequent (i.e., recurrent) concussion sustained during the study period. Controlling for age and position, significant predictors of time loss were postconcussion headache (p < 0.001), low energy or fatigue (p = 0.01), amnesia (p = 0.02) and abnormal neurologic examination (p = 0.01). Using a previously suggested time loss cut-point of 10 days, headache (odds ratio [OR] 2.17, 95% CI 1.33-3.54) and low energy or fatigue (OR 1.72, 95% CI 1.04-2.85) were significant predictors of time loss of more than 10 days. Postconcussion headache, low energy or fatigue, amnesia and abnormal neurologic examination were significant predictors of time loss among professional hockey players.

Effects of neck strength training on isometric neck strength in rugby union players.

PubMed

Geary, Kevin; Green, Brian S; Delahunt, Eamonn

2014-11-01

To investigate the effectiveness of a neck strengthening program on the isometric neck strength profile of male rugby union players. Controlled laboratory study. Professional rugby union club. Fifteen professional and 10 semiprofessional rugby union players. The 15 professional players undertook a 5-week neck strengthening intervention, which was performed twice per week, whereas the 10 semiprofessional players acted as the control group. Isometric strength of the neck musculature was tested using a hand-held dynamometer, for flexion (F), extension (E), left-side flexion (LSF), and right-side flexion (RSF). Preintervention and postintervention evaluations were undertaken. No significant between-group differences in isometric neck strength were noted preintervention. A significant main effect for time was observed (P < 0.05), whereby the intervention group increased isometric neck strength in all planes after the 5-week intervention (F preintervention = 334.45 ± 39.31 N vs F postintervention 396.05 ± 75.55 N; E preintervention = 606.19 ± 97.34 vs E postintervention = 733.88 ± 127.16 N; LSF preintervention = 555.56 ± 88.34 N vs LSF postintervention = 657.14 ± 122.99 N; RSF preintervention = 570.00 ± 106.53 N vs RSF postintervention = 668.00 ± 142.18 N). No significant improvement in neck strength was observed for control group participants. The results of the present study indicate that a 5-week neck strengthening program improves isometric neck strength in rugby union players, which may have implications for injury prevention, screening, and rehabilitation. The strengthening program described in the present study may facilitate rehabilitation specialists in the development of neck injury prevention, screening, and rehabilitation protocols.

Self-Managed Exercises, Fitness and Strength Training, and Multifidus Muscle Size in Elite Footballers.

PubMed

Hides, Julie A; Walsh, Jazmin C; Smith, Melinda M Franettovich; Mendis, M Dilani

2017-07-01

  Low back pain (LBP) and lower limb injuries are common among Australian Football League (AFL) players. Smaller size of 1 key trunk muscle, the lumbar multifidus (MF), has been associated with LBP and injuries in footballers. The size of the MF muscle has been shown to be modifiable with supervised motor-control training programs. Among AFL players, supervised motor-control training has also been shown to reduce the incidence of lower limb injuries and was associated with increased player availability for games. However, the effectiveness of a self-managed MF exercise program is unknown.   To investigate the effect of self-managed exercises and fitness and strength training on MF muscle size in AFL players with or without current LBP.   Cross-sectional study.   Professional AFL context.   Complete data were available for 242 players from 6 elite AFL clubs.   Information related to the presence of LBP and history of injury was collected at the start of the preseason. At the end of the preseason, data were collected regarding performance of MF exercises as well as fitness and strength training. Ultrasound imaging of the MF muscle was conducted at the start and end of the preseason.   Size of the MF muscles.   An interaction effect was found between performance of MF exercises and time (F = 13.89, P ≤ .001). Retention of MF muscle size was greatest in players who practiced the MF exercises during the preseason (F = 4.77, P = .03). Increased adherence to fitness and strength training was associated with retained MF muscle size over the preseason (F = 5.35, P = .02).   Increased adherence to a self-administered MF exercise program and to fitness and strength training was effective in maintaining the size of the MF muscle in the preseason.

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 strain injury. The maximal speed, leg strength, ability to produce maximal power, endurance capacity, and hamstring flexibility was similar for both groups. Thus, a repeated sprint test consisting of 8 × 20 m could be used as a field-based diagnostic tool to identify players in need of reconditioning programs to ensure complete post-injury rehabilitation. PMID:28190999

Character selecting advisor for a role-playing game

NASA Technical Reports Server (NTRS)

Redfield, Carol L.; Berlanga, Felicia

1994-01-01

Role-playing games have been a source of much pleasure and merriment for people of all ages. The process of developing a character for a role-playing game is usually very, very time consuming, delaying what many players consider the most entertaining part of the game. An expert system has been written to assist a player in creating a character by guiding the player through a series of questions. This paper discusses the selection of this topic, the knowledge engineering, the software development, and the resulting program that cuts the time of character development from about 4 hours to 30 minutes. The program was written on a PC and an Apollo in CLIPS 4.3 and currently runs on the Apollo.

Openlobby: an open game server for lobby and matchmaking

NASA Astrophysics Data System (ADS)

Zamzami, E. M.; Tarigan, J. T.; Jaya, I.; Hardi, S. M.

2018-03-01

Online Multiplayer is one of the most essential feature in modern games. However, while developing a multiplayer feature can be done with a simple computer networking programming, creating a balanced multiplayer session requires more player management components such as game lobby and matchmaking system. Our objective is to develop OpenLobby, a server that available to be used by other developers to support their multiplayer application. The proposed system acts as a lobby and matchmaker where queueing players will be matched to other player according to a certain criteria defined by developer. The solution provides an application programing interface that can be used by developer to interact with the server. For testing purpose, we developed a game that uses the server as their multiplayer server.

Comparison of somatotype values of football players in two professional league football teams according to the positions.

PubMed

Orhan, Ozlem; Sagir, Mehmet; Zorba, Erdal

2013-06-01

This study compared the somatotype values of football players according to their playing positions. The study aimed to determine the physical profiles of players and to analyze the relationships between somatotypes and playing positions. Study participants were members of two teams in the Turkey Professional Football League, Gençlerbirligi Sports Team (GB) (N = 24) and Gençlerbirligi Oftas Sports Team (GBO) (N = 24). Anthropometric measurements of the players were performed according to techniques suggested by the Anthropometric Standardization Reference Manual (ASRM) and International Biological Program (IBP). In somatotype calculations, triceps, subscapular, supraspinale and calf skinfold thickness, humerus bicondylar, femur bicondylar, biceps circumference, calf circumference and body weight and height were used. Statistical analysis of the data was performed using the Graph Pad prism Version 5.00 for Windows (Graph Pad Software, San Diego California USA); somatotype calculations and analyses used the Somatotype 1.1 program and graphical representations of the results were produced. Analysis of non-parametric (two independent samples) Mann-Whitney U Test of the player data showed that there were no statistically significant differences between the two teams. The measurements indicated that, when all of the GB and GBO players were evaluated collectively, their average somatotypes were balanced mesomorph. The somatotypes of GBO goalkeepers were generally ectomorphic mesomorph; GB goalkeepers were balanced mesomorphic, although they were slightly endomorphic.

A four year prospective study of injuries in elite Ontario youth provincial and national soccer players during training and matchplay

PubMed Central

Mohib, Milad; Moser, Nicholas; Kim, Richard; Thillai, Maathavan; Gringmuth, Robert

2014-01-01

Introduction: With over 200 million amateur players worldwide, soccer is one of the most popular and internationally recognized sports today. By understanding how and why soccer injuries occur we hope to reduce prevalent injuries amongst elite soccer athletes. Methods: Via a prospective cohort, we examined both male and female soccer players eligible to train with the Ontario Soccer Association provincial program between the ages of 13 to 17 during the period of October 10, 2008 and April 20, 2012. Data collection occurred during all player exposures to potential injury. Exposures occurred at the Soccer Centre, Ontario Training grounds and various other venues on multiple playing surfaces. Results: A total number of 733 injuries were recorded. Muscle strain, pull or tightness was responsible for 45.6% of all injuries and ranked as the most prevalent injury. Discussion: As anticipated, the highest injury reported was muscular strain, which warrants more suitable preventive programs aimed at strengthening and properly warming up the players’ muscles. PMID:25550661

Lower reinjury rate with a coach-controlled rehabilitation program in amateur male soccer: a randomized controlled trial.

PubMed

Hägglund, Martin; Waldén, Markus; Ekstrand, Jan

2007-09-01

Soccer injuries are common, and athletes returning to play after injury are especially at risk. Few studies have investigated how to prevent reinjury. The rate of reinjury is reduced using a coach-controlled rehabilitation program. Randomized controlled trial; Level of evidence, 1. Twenty-four male amateur soccer teams were randomized into an intervention (n = 282) and control group (n = 300). The intervention was implemented by team coaches and consisted of information about risk factors for reinjury, rehabilitation principles, and a 10-step progressive rehabilitation program including return to play criteria. During the 2003 season, coaches reported individual exposure and all time loss injuries were evaluated by a doctor and a physiotherapist. Four teams (n = 100) withdrew from the study after randomization, leaving 10 teams with 241 players for analysis in both groups. There were 90 injured players (132 injuries) in the intervention group, and 10 of these (11%) suffered 14 reinjuries during the season. In the control group, 23 of 79 injured players (29%) had 40 recurrences (134 injuries). A Cox regression analysis showed a 66% reinjury risk reduction in the intervention group for all injury locations (hazard ratio [HR] 0.34, 95% confidence interval [CI] 0.16-0.72, P = .0047) and 75% for lower limb injuries (HR 0.25, 95% CI 0.11-0.57, P < .001). The preventive effect was greatest within the first week of return to play. Injured players in the intervention group complied with the intervention for 90 of 132 injuries (68%). The reinjury rate in amateur male soccer players was reduced after a controlled rehabilitation program implemented by coaches.

Six weeks of multi-station program on the knee proprioception and performance of futsal players.

PubMed

Pérez-Silvestre, Ángel; Albert-Lucena, Daniel; Gómez-Chiguano, Guido F; Plaza-Manzano, Gustavo; Pecos-Martín, Daniel; Gallego-Izquierdo, Tomás; Martín-Casas, Patricia; Romero-Franco, Natalia

2018-03-27

Proprioception and vertical jump are important parameters in the performance and prevention of injuries in futsal. However, very few studies have analyzed the role of multi-station exercises to improve these variables. The purpose of this study was to assess the effects of a six-week multi-station exercise program on knee joint position sense (JPS) and countermovement jump (CMJ) of futsal players. Thirty-four male futsal players randomly classified into experimental (n = 17) or control group (n = 17). The experimental group included a multi-station exercise protocol to their training routines (2 times/week - 6 weeks); the control group continued their training routines. All the players completed similar training routines outside of the multi-station exercises. Before (baseline), just after the intervention (Post6Wk) and four weeks later (Post10Wk), CMJ and knee JPS (absolute, relative and variable angular error: AAE, RAE and VAE, respectively) were evaluated. ANOVA showed that the experimental group significantly decreased VAE at Post10Wk compared to baseline, suggestive of greater proprioceptive precision, while the control group significantly increased AAE, RAE and VAE at Post10Wk compared to baseline. The experimental group exhibited lower and thus, better AAE and VAE than the control group at Post10Wk, although no significant differences were found at Post6Wk. No significant differences was found in the CMJ. A six weeks of multi-station program may help improve proprioceptive precision of futsal players, even one month after finishing the 6-wk multi-station training program. However, this is not long enough to improve proprioceptive acuity and maximum vertical jump. Therefore, the meaningful of these results in term of performance are unclear.

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.

Movement Demands and Metabolic Power Comparisons Between Elite and Subelite Australian Footballers.

PubMed

Johnston, Richard J; Watsford, Mark L; Austin, Damien J; Pine, Matthew J; Spurrs, Robert W

2015-10-01

This study examined the differences in movement demands and metabolic power output of elite and subelite Australian football (AF) players and quantified the movement profiles of a subelite AF competition. Movement variables were collected from AF players using Global Positioning System devices over 2 AF League (elite) and North East Australian Football League (NEAFL, subelite) seasons. A total of 500 files were collected from 37 elite and subelite nomadic AF players. NEAFL players covered 13,547 m at an average speed of 124.5 m·min(-1). Elite players performed more high-speed running (5.7-6.3%) and high acceleration and deceleration efforts (1.9-14.7%, p ≤ 0.05). The elite players had a higher mean metabolic power output (3.2%) and time spent at the very high power zone (15.9%, p ≤ 0.05). In contrast, elite players recorded a lower total match duration than the subelite players (4%, p ≤ 0.05). The contrasting amount of high-intensity activities performed by the 2 groups demonstrates the need to alter the training programs of subelite players to ensure they are capable of meeting the demands of elite football. The differences in match duration suggest that reducing subelite players' match time through increasing their rotations would assist the replication of movement profiles of elite players.

Longitudinal development of match-running performance in elite male youth soccer players.

PubMed

Saward, C; Morris, J G; Nevill, M E; Nevill, A M; Sunderland, C

2016-08-01

This study longitudinally examined age-related changes in the match-running performance of retained and released elite youth soccer players aged 8-18 years. The effect of playing position on age-related changes was also considered. Across three seasons, 263 elite youth soccer players were assessed in 1-29 competitive matches (988 player-matches). For each player-match, total distance and distances covered at age group-specific speed zones (low-speed, high-speed, sprinting) were calculated using 1 Hz or 5 Hz GPS. Mixed modeling predicted that match-running performance developed nonlinearly, with age-related changes best described with quadratic age terms. Modeling predicted that playing position significantly modified age-related changes (P < 0.05) and retained players covered significantly more low-speed distance compared with released players (P < 0.05), by 75 ± 71 m/h (mean ± 95% CI; effect size ± 95% CI: 0.35 ± 0.34). Model intercepts randomly varied, indicating differences between players in match-running performance unexplained by age, playing position or status. These findings may assist experts in developing training programs specific to the match play demands of players of different ages and playing positions. Although retained players covered more low-speed distance than released players, further study of the actions comprising low-speed distance during match play is warranted to better understand factors differentiating retained and released players. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Physiological Characteristics of Incoming Freshmen Field Players in a Men’s Division I Collegiate Soccer Team

PubMed Central

Lockie, Robert G.; Davis, DeShaun L.; Birmingham-Babauta, Samantha A.; Beiley, Megan D.; Hurley, Jillian M.; Stage, Alyssa A.; Stokes, John J.; Tomita, Tricia M.; Torne, Ibett A.; Lazar, Adrina

2016-01-01

Freshmen college soccer players will have lower training ages than their experienced teammates (sophomores, juniors, seniors). How this is reflected in field test performance is not known. Freshmen (n = 7) and experienced (n = 10) male field soccer players from the same Division I school completed soccer-specific tests to identify potential differences in incoming freshmen. Testing included: vertical jump (VJ), standing broad jump, and triple hop (TH); 30-m sprint, (0–5, 5–10, 0–10, and 0–30 m intervals); 505 change-of-direction test; Yo-Yo Intermittent Recovery Test Level 2 (YYIRT2); and 6 × 30-m sprints to measure repeated-sprint ability. A MANOVA with Bonferroni post hoc was conducted on the performance test data, and effect sizes and z-scores were calculated from the results for magnitude-based inference. There were no significant between-group differences in the performance tests. There were moderate effects for the differences in VJ height, left-leg TH, 0–5, 0–10 and 0–30 m sprint intervals, and YYIRT2 (d = 0.63–1.18), with experienced players being superior. According to z-score data, freshmen had meaningful differences below the squad mean in the 30-m sprint, YYIRT2, and jump tests. Freshmen soccer players may need to develop linear speed, high-intensity running, and jump performance upon entering a collegiate program. PMID:29910282

Creating a Supportive Environment among Youth Football Players: A Qualitative Study of French and Norwegian Youth Grassroots Football Coaches

ERIC Educational Resources Information Center

Larsen, Torill; Van Hoye, Aurelie; Tjomsland, Hege Eikeland; Holsen, Ingrid; Wold, Bente; Heuzé, Jean-Philippe; Samdal, Oddrun; Sarrazin, Philippe

2015-01-01

Purpose: The health promoting benefits of sport participation are under-utilized and should be further developed, particularly at the grassroots level. The purpose of this paper is to examine how grassroots coaches in youth football perceive their coaching practices after participating in a community-based coach education program aimed at…

Autogenerator-based modelling framework for development of strategic games simulations: rational pigs game extended.

PubMed

Fabac, Robert; Radošević, Danijel; Magdalenić, Ivan

2014-01-01

When considering strategic games from the conceptual perspective that focuses on the questions of participants' decision-making rationality, the very issues of modelling and simulation are rarely discussed. The well-known Rational Pigs matrix game has been relatively intensively analyzed in terms of reassessment of the logic of two players involved in asymmetric situations as gluttons that differ significantly by their attributes. This paper presents a successful attempt of using autogenerator for creating the framework of the game, including the predefined scenarios and corresponding payoffs. Autogenerator offers flexibility concerning the specification of game parameters, which consist of variations in the number of simultaneous players and their features and game objects and their attributes as well as some general game characteristics. In the proposed approach the model of autogenerator was upgraded so as to enable program specification updates. For the purpose of treatment of more complex strategic scenarios, we created the Rational Pigs Game Extended (RPGE), in which the introduction of a third glutton entails significant structural changes. In addition, due to the existence of particular attributes of the new player, "the tramp," one equilibrium point from the original game is destabilized which has an influence on the decision-making of rational players.

Autogenerator-Based Modelling Framework for Development of Strategic Games Simulations: Rational Pigs Game Extended

PubMed Central

Magdalenić, Ivan

2014-01-01

When considering strategic games from the conceptual perspective that focuses on the questions of participants' decision-making rationality, the very issues of modelling and simulation are rarely discussed. The well-known Rational Pigs matrix game has been relatively intensively analyzed in terms of reassessment of the logic of two players involved in asymmetric situations as gluttons that differ significantly by their attributes. This paper presents a successful attempt of using autogenerator for creating the framework of the game, including the predefined scenarios and corresponding payoffs. Autogenerator offers flexibility concerning the specification of game parameters, which consist of variations in the number of simultaneous players and their features and game objects and their attributes as well as some general game characteristics. In the proposed approach the model of autogenerator was upgraded so as to enable program specification updates. For the purpose of treatment of more complex strategic scenarios, we created the Rational Pigs Game Extended (RPGE), in which the introduction of a third glutton entails significant structural changes. In addition, due to the existence of particular attributes of the new player, “the tramp,” one equilibrium point from the original game is destabilized which has an influence on the decision-making of rational players. PMID:25254228

Performance aspects of an injury prevention program: a ten-week intervention in adolescent female football players.

PubMed

Steffen, K; Bakka, H M; Myklebust, G; Bahr, R

2008-10-01

The injury rate in football is high, and effective injury prevention methods are needed. An exercise program, the "11," has been designed to prevent the most common injury types in football. However, the effect of such a program on performance is not known. The aim of this randomized-controlled trial was to investigate the effect of the "11" on performance after a 10-week training period. Thirty-four adolescent female football players were randomly assigned to either an intervention (n=18) or a control group (n=16). The "11" is a 15-min program consisting of ten exercises for core stability, lower extremity strength, balance and agility. Performance tests included isokinetic and isometric strength protocols for the quadriceps and hamstrings, isometric hip adduction and abduction strength, vertical jump tests, sprint running and soccer skill tests. There was no difference between the intervention and control groups in the change in performance from the pre- to post-test for any of the tests used. In conclusion, no effect was observed on a series of performance tests in a group of adolescent female football players using the "11" as a structured warm-up program.

Motivational Traits of Elite Young Soccer Players

ERIC Educational Resources Information Center

Stewart, Craig; Meyers, Michael C.

2004-01-01

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

Influence of Yo-Yo IR2 Scores on Internal and External Workloads and Fatigue Responses of Tag Football Players during Tournament Competition

PubMed Central

2015-01-01

The purpose of this study was to: a) identify changes in jump height and perceived well-being as indirect markers of fatigue, b) determine the internal and external workloads performed by players, and c) examine the influence of Yo-Yo IR2 on changes in jump height, perceived well-being and internal and external workloads during a tag football tournament. Microtechnology devices combined with heart rate (HR) chest straps provided external and internal measures of match work-rate and workload for twelve male tag football players during the 2014 Australian National Championships. Jump height and perceived well-being were assessed prior to and during the tournament as indirect measures of fatigue. Changes in work-rate, workload and fatigue measures between high- and low-fitness groups were examined based on players’ Yo-Yo IR2 score using a median split technique. The low- and high-fitness groups reported similar mean HR, PlayerloadTM/min, and distance/min for matches, however the low-fitness group reported higher perceived match-intensities (ES = 0.90–1.35) for several matches. Further, the high-fitness group reported higher measures of tournament workload, including distance (ES = 0.71), PlayerloadTM (ES = 0.85) and Edwards’ training impulse (TRIMP) (ES = 1.23) than the low-fitness group. High- and low-fitness groups both showed large decreases (ES = 1.46–1.49) in perceived well-being during the tournament, although jump height did not decrease below pre-tournament values. Increased Yo-Yo IR2 appears to offer a protective effect against player fatigue despite increased workloads during a tag football tournament. It is vital that training programs adequately prepare tag football players for tournament competition to maximise performance and minimise player fatigue. PMID:26465599

Physiologic performance test differences in female volleyball athletes by competition level and player position.

PubMed

Schaal, Monique; Ransdell, Lynda B; Simonson, Shawn R; Gao, Yong

2013-07-01

The purpose of this study was to examine physiologic performance test differences by competition level (high school and Division-I collegiate athletes) and player position (hitter, setter, defensive specialist) in 4 volleyball-related tests. A secondary purpose was to establish whether a 150-yd shuttle could be used as a field test to assess anaerobic capacity. Female participants from 4 varsity high school volleyball teams (n = 27) and 2 Division-I collegiate volleyball teams (n = 26) were recruited for the study. Participants completed 4 performance-based field tests (vertical jump, agility T-test, and 150- and 300-yd shuttle runs) after completing a standardized dynamic warm-up. A 2-way multivariate analysis of variance with Bonferroni post hoc adjustments (when appropriate) and effect sizes were used for the analyses. The most important findings of this study were that (a) college volleyball athletes were older, heavier, and taller than high school athletes; (b) high school athletes had performance deficiencies in vertical jump/lower-body power, agility, and anaerobic fitness; (c) lower-body power was the only statistically significant difference in the performance test measures by player position; and (d) the correlation between the 150- and 300-yd shuttle was moderate (r = 0.488). Female high school volleyball players may enhance their ability to play collegiate volleyball by improving their vertical jump, lower-body power, agility, and anaerobic fitness. Furthermore, all player positions should emphasize lower-body power conditioning. These physical test scores provide baseline performance scores that should help strength and conditioning coaches create programs that will address deficits in female volleyball player performance, especially as they transition from high school to college.

Growth status and estimated growth rate of youth football players: a community-based study.

PubMed

Malina, Robert M; Morano, Peter J; Barron, Mary; Miller, Susan J; Cumming, Sean P

2005-05-01

To characterize the growth status of participants in community-sponsored youth football programs and to estimate rates of growth in height and weight. Mixed-longitudinal over 2 seasons. Two communities in central Michigan. Members of 33 youth football teams in 2 central Michigan communities in the 2000 and 2001 seasons (Mid-Michigan PONY Football League). Height and weight of all participants were measured prior to each season, 327 in 2000 and 326 in 2001 (n = 653). The body mass index (kg/m) was calculated. Heights and weights did not differ from season to season and between the communities; the data were pooled and treated cross-sectionally. Increments of growth in height and weight were estimated for 166 boys with 2 measurements approximately 1 year apart to provide an estimate of growth rate. Growth status (size-attained) of youth football players relative to reference data (CDC) for American boys and estimated growth rate relative to reference values from 2 longitudinal studies of American boys. Median heights of youth football players approximate the 75th percentiles, while median weights approximate the 75th percentiles through 11 years and then drift toward the 90th percentiles of the reference. Median body mass indexes of youth football players fluctuate about the 85th percentiles of the reference. Estimated growth rates in height approximate the reference and may suggest earlier maturation, while estimated growth rates in weight exceed the reference. Youth football players are taller and especially heavier than reference values for American boys. Estimated rates of growth in height approximate medians for American boys and suggest earlier maturation. Estimated rates of growth in weight exceed those of the reference and may place many youth football players at risk for overweight/obesity, which in turn may be a risk factor for injury.

ToTCompute: A Novel EEG-Based TimeOnTask Threshold Computation Mechanism for Engagement Modelling and Monitoring

ERIC Educational Resources Information Center

Ghergulescu, Ioana; Muntean, Cristina Hava

2016-01-01

Engagement influences participation, progression and retention in game-based e-learning (GBeL). Therefore, GBeL systems should engage the players in order to support them to maximize their learning outcomes, and provide the players with adequate feedback to maintain their motivation. Innovative engagement monitoring solutions based on players'…

Repeated-Sprint Sequences During Female Soccer Matches Using Fixed and Individual Speed Thresholds.

PubMed

Nakamura, Fábio Y; Pereira, Lucas A; Loturco, Irineu; Rosseti, Marcelo; Moura, Felipe A; Bradley, Paul S

2017-07-01

Nakamura, FY, Pereira, LA, Loturco, I, Rosseti, M, Moura, FA, and Bradley, PS. Repeated-sprint sequences during female soccer matches using fixed and individual speed thresholds. J Strength Cond Res 31(7): 1802-1810, 2017-The main objective of this study was to characterize the occurrence of single sprint and repeated-sprint sequences (RSS) during elite female soccer matches, using fixed (20 km·h) and individually based speed thresholds (>90% of the mean speed from a 20-m sprint test). Eleven elite female soccer players from the same team participated in the study. All players performed a 20-m linear sprint test, and were assessed in up to 10 official matches using Global Positioning System technology. Magnitude-based inferences were used to test for meaningful differences. Results revealed that irrespective of adopting fixed or individual speed thresholds, female players produced only a few RSS during matches (2.3 ± 2.4 sequences using the fixed threshold and 3.3 ± 3.0 sequences using the individually based threshold), with most sequences composing of just 2 sprints. Additionally, central defenders performed fewer sprints (10.2 ± 4.1) than other positions (fullbacks: 28.1 ± 5.5; midfielders: 21.9 ± 10.5; forwards: 31.9 ± 11.1; with the differences being likely to almost certainly associated with effect sizes ranging from 1.65 to 2.72), and sprinting ability declined in the second half. The data do not support the notion that RSS occurs frequently during soccer matches in female players, irrespective of using fixed or individual speed thresholds to define sprint occurrence. However, repeated-sprint ability development cannot be ruled out from soccer training programs because of its association with match-related performance.

Effect of motor control training on muscle size and football games missed from injury.

PubMed

Hides, Julie A; Stanton, Warren R; Mendis, M Dilani; Gildea, Jan; Sexton, Margot J

2012-06-01

This panel-randomized intervention trial was designed to examine the effect of a motor control training program for elite Australian Football League players with and without low back pain (LBP). The outcome measures included cross-sectional area (CSA) and symmetry of multifidus, quadratus lumborum, and psoas muscles and the change in CSA of the trunk in response to an abdominal drawing-in task. These measures of muscle size and function were performed using magnetic resonance imaging. Availability of players for competition games was used to assess the effect of the intervention on the occurrence of injuries. The motor control program involved performance of voluntary contractions of the multifidus and transversus abdominis muscles while receiving feedback from ultrasound imaging. Because all players were to receive the intervention, the trial was delivered as a stepped-wedge design with three treatment arms (a 15-wk intervention, a 8-wk intervention, and a waitlist control who received a 7-wk intervention toward the end of the playing season). Players participated in a Pilates program when they were not receiving the intervention. The intervention program was associated with an increase in multifidus muscle size relative to results in the control group. The program was also associated with an improved ability to draw-in the abdominal wall. Intervention was commensurate with an increase in availability for games and a high level of perceived benefit. The motor control program delivered to elite footballers was effective, with demonstrated changes in the size and control of the targeted muscles. In this study, footballers who received the intervention early in the season missed fewer games because of injury than those who received it late in the playing season.

Longitudinal motor performance development in early adolescence and its relationship to adult success: An 8-year prospective study of highly talented soccer players

PubMed Central

Kelava, Augustin; Raabe, Johannes; Höner, Oliver

2018-01-01

Several talent identification and development (TID) programs in soccer have implemented diagnostics to measure players’ motor performance. Yet, there is a lack of research investigating the relationship between motor development in adolescence and future, adult performance. This longitudinal study analyzed the three-year development of highly talented young soccer players’ speed abilities and technical skills and examined the relevance of this development to their adult success. The current research sample consisted of N = 1,134 players born between 1993 and 1995 who were selected for the German Soccer Association’s TID program and participated in nationwide motor diagnostics (sprinting, agility, dribbling, ball control, shooting) four times between the Under 12 (U12) and Under 15 (U15) age class. Relative age (RA) was assessed for all players, and a total motor score was calculated based on performances in the individual tests. In order to investigate players’ future success, participants were divided into two groups according to their adult performance level (APL) in the 2014/2015 season: Elite (1st-5th German division; N = 145, 12.8%) and non-elite players (lower divisions; N = 989, 87.2%). Using multilevel regression analyses each motor performance was predicted by Time, Time2 (level-1 predictors), APL, and RA (level-2 covariates) with simultaneous consideration for interaction effects between the respective variables. Time and Time2 were significant predictors for each test performance. A predictive value for RA was confirmed for sprinting and the total motor score. A significant relationship between APL and the motor score as well as between APL and agility, dribbling, ball control, and shooting emerged. Interaction effects distinctly failed to reach significance. The study found a non-linear improvement in players’ performance for all considered motor performance factors over a three-year period from early to middle adolescence. While their predictive value for future success was confirmed by a significant relationship between APL and most of the considered factors, there was no significant interaction between APL and Time. These findings indicate that future elite players had already been better at the beginning of the TID program and maintained this high level throughout their promotion from U12 to U15. PMID:29723200

Effects of Badminton Expertise on Representational Momentum: A Combination of Cross-Sectional and Longitudinal Studies

PubMed Central

Jin, Hua; Wang, Pin; Fang, Zhuo; Di, Xin; Ye, Zhuo’er; Xu, Guiping; Lin, Huiyan; Cheng, Yongmin; Li, Yongjie; Xu, Yong; Rao, Hengyi

2017-01-01

Representational momentum (RM) has been found to be magnified in experts (e.g., sport players) with respect to both real and implied motion in expert-familiar domains. However, it remains unclear whether similar effects can be achieved in expert-unfamiliar domains, especially within the context of implied motion. To answer this question, we conducted two independent experiments using an implied motion paradigm and examined the expert effects of badminton training on RM in both adult and child players. In Experiment 1, we used a cross-sectional design and compared RM between adult professional badminton players and matched controls. The results revealed significantly enhanced RM for adult players, supporting the expert effect in expert-unfamiliar domains for implied motion. However, cross-sectional studies could not ascertain whether the observed expert effect was due to innate factors or expertise acquirement. Therefore, in Experiment 2, we used a longitudinal design and compared RM between two groups of child participants, naming child players who had enrolled professional badminton training program at a sports school and age-matched peer non-players who attended an ordinary primary school without sports training. Before training, there were no differences in RM among child players, their non-player peers, and adult non-players. However, after 4 years of badminton training, child players demonstrated significantly enhanced RM compared to themselves prior to training. The increased RM observed in both adult and child players suggests that badminton expertise modulates implied motion RM. PMID:28970810

Sports Training Support Method by Self-Coaching with Humanoid Robot

NASA Astrophysics Data System (ADS)

Toyama, S.; Ikeda, F.; Yasaka, T.

2016-09-01

This paper proposes a new training support method called self-coaching with humanoid robots. In the proposed method, two small size inexpensive humanoid robots are used because of their availability. One robot called target robot reproduces motion of a target player and another robot called reference robot reproduces motion of an expert player. The target player can recognize a target technique from the reference robot and his/her inadequate skill from the target robot. Modifying the motion of the target robot as self-coaching, the target player could get advanced cognition. Some experimental results show some possibility as the new training method and some issues of the self-coaching interface program as a future work.

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.

Player-Tracking Technology: Half-Full or Half-Empty Glass?

PubMed

Buchheit, Martin; Simpson, Ben Michael

2017-04-01

With the ongoing development of microtechnology, player tracking has become one of the most important components of load monitoring in team sports. The 3 main objectives of player tracking are better understanding of practice (provide an objective, a posteriori evaluation of external load and locomotor demands of any given session or match), optimization of training-load patterns at the team level, and decision making on individual players' training programs to improve performance and prevent injuries (eg, top-up training vs unloading sequences, return to play progression). This paper discusses the basics of a simple tracking approach and the need to integrate multiple systems. The limitations of some of the most used variables in the field (including metabolic-power measures) are debated, and innovative and potentially new powerful variables are presented. The foundations of a successful player-monitoring system are probably laid on the pitch first, in the way practitioners collect their own tracking data, given the limitations of each variable, and how they report and use all this information, rather than in the technology and the variables per se. Overall, the decision to use any tracking technology or new variable should always be considered with a cost/benefit approach (ie, cost, ease of use, portability, manpower/ability to affect the training program).

Comparison of Two Kinds of Endurance Training Programs on the Effects of the Ability to Recover in Amateur Soccer Players

PubMed Central

Rogan, Slavko

2015-01-01

Background: High intensity intermittent aerobic exercise is an elementary endurance training exercise to build soccer endurance. Many studies exist with professional soccer players. But limited research has been conducted with amateur soccer players. Objectives: The aim of this study was to compare and assess the effects of the shuttle-run method and the Hoff-track method on the ability to recover in amateur soccer players within three weeks. Patients and Methods: Two amateur soccer teams were randomly assigned to shuttle-run group (n = 24; SRG) (SRG: shuttle-run group) or Hoff-track group (n = 18; HTG) (HTG: hoff-track group). They performed 2 times/week over three weeks their program. SRG performed a 20 m high speed shuttle-run until exhaustion and HTG covered at their highest speed level an obstacle track. Before and after training the yo-yo intermittent recovery test level 2 (YYIRTL2) was conducted. Results: Significant differences were observed within (P < 0.05) and between the groups (P = 0.06; ES = 0.50) in distance covering during YYIRTL2. Conclusions: Both training methods seem to improve the ability to recover in amateur soccer players within a short time period during the competition season. PMID:26448831

Sport specific fitness testing of elite badminton players.

PubMed Central

Chin, M K; Wong, A S; So, R C; Siu, O T; Steininger, K; Lo, D T

1995-01-01

There is a scarcity of descriptive data on the performance capacity of elite badminton players, whose fitness requirements are quite specific. The purpose of this paper is to investigate the physiological response of elite badminton players in a sport-specific fitness test. Twelve Hong Kong national badminton team players performed a field test on a badminton court. Six light bulbs were connected to a programming device causing individual bulbs to light up in a given sequence. The players were instructed to react to the flashes by running towards them, and striking shuttles mounted in the vicinity of the bulbs. Exercise intensity was controlled by altering the interval between successive lightings. A low correlation (r = 0.65) was found between the results of the field test and the rank-order list of subjects, based on an objective on-field physiological assessment and subjective ranking. This may be explained by the requirements of other factors besides physical fitness which contribute to success in elite level badminton competition. These factors may include, for example, technical skill, mental power, and aesthetic judgements on the court. Maximum mean (s.d.) heart rate data (187(8) beats.min-1) and blood lactate values (10.4(2.9) mmol.l-1) in this study showed that players were under maximal load during the field test. From the testing data, it seems reasonable to speculate that the intensity of level 3 (20 light pulses.min-1; 3.0 s.pulse-1) and level 4 (22 light pulses.min-1; 2.7 s.pulse-1) simulates the requirement of actual games energy expenditure of the Hong Kong badminton players exercising at close to their anaerobic threshold. The results also show that an estimate of fitness can be derived from measurements involving exercise closely resembling that which is specific for the sports activity in question. Improved training advice and guidance may result from such studies. PMID:8800846

A six-week neuromuscular training program for competitive junior tennis players.

PubMed

Barber-Westin, Sue D; Hermeto, Alex A; Noyes, Frank R

2010-09-01

This study evaluated the effectiveness of a tennis-specific training program on improving neuromuscular indices in competitive junior players. Tennis is a demanding sport because it requires speed, agility, explosive power, and aerobic conditioning along with the ability to react and anticipate quickly, and there are limited studies that evaluate these indices in young players after a multiweek training program. The program designed for this study implemented the essential components of a previously published neuromuscular training program and also included exercises designed to improve dynamic balance, agility, speed, and strength. Fifteen junior tennis players (10 girls, 5 boys; mean age, 13.0 +/- 1.5 years) who routinely participated in local tournaments and high-school teams participated in the 6-week supervised program. Training was conducted 3 times a week, with sessions lasting 1.5 hours that included a dynamic warm-up, plyometric and jump training, strength training (lower extremity, upper extremity, core), tennis-specific drills, and flexibility. After training, statistically significant improvements and large-to-moderate effect sizes were found in the single-leg triple crossover hop for both legs (p < 0.05), the baseline forehand (p = 0.006) and backhand (p = 0.0008) tests, the service line (p = 0.0009) test, the 1-court suicide (p < 0.0001), the 2-court suicide (p = 0.02), and the abdominal endurance test (p = 0.01). Mean improvements between pretrain and posttrain test sessions were 15% for the single-leg triple crossover hop, 10-11% for the baseline tests, 18% for the service line test, 21% for the 1-court suicide, 10% for the 2-court suicide, and 76% for the abdominal endurance test. No athlete sustained an injury or developed an overuse syndrome as a result of the training program. The results demonstrate that this program is feasible, low in cost, and appears to be effective in improving the majority of neuromuscular indices tested. We accomplished our goal of developing training and testing procedures that could all be performed on the tennis court.

Shorter time to first injury in first year professional football players: A cross-club comparison in the Australian Football League.

PubMed

Fortington, Lauren V; Berry, Jason; Buttifant, David; Ullah, Shahid; Diamantopoulou, Kathy; Finch, Caroline F

2016-01-01

Australian Football League (AFL) players have a high risk of injury. Anecdotally, this injury risk is greater in emerging players (i.e. those in their first year), compared with established players (with 3+ years of experience). This study aimed to conduct the first comparison of injury risk and playing experience in these two player groups across a large number of AFL clubs. Prospective, cohort. Injuries, game participation and training participation were collected weekly by 8 AFL clubs for 61 emerging and 64 established players. Injury incidence rates (IIR) and Cox proportional hazard models for time to first injury, separately for games and training, were computed. The game IIR was significantly higher for emerging than established players: 45.6 (95% CI: 35.7, 57.6) versus 18.3 (95% CI: 13.1, 24.9) per 1000 game-hours. Emerging players also had a higher training IIR than did the established players: 9.6 (95% CI: 7.6, 11.9) versus 8.9 (95% CI: 7.0, 11.1) per 1000 training-hours. Emerging players were significantly less likely to remain injury free in games than established players (HR=3.46, 95% CI: 1.27, 9.45). A similar outcome was seen in training sessions, although to a lesser degree (HR=1.41, 95% CI: 1.19, 1.69). Despite efforts to modify the playing/training program of emerging players, this group remain at greater risk of injury in games and training sessions, compared with established players. Continued efforts should be made toward understanding reasons for this increased risk to better prevent injury during the early years of a professional football career. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

The Effects of Plyometric Type Neuromuscular Training on Postural Control Performance of Male Team Basketball Players.

PubMed

Asadi, Abbas; Saez de Villarreal, Eduardo; Arazi, Hamid

2015-07-01

Anterior cruciate ligament injuries are common in basketball athletes; common preventive programs for decreasing these injures may be enhancing postural control (PC) or balance with plyometric training. This study investigated the efficiency of plyometric training program within basketball practice to improve PC performance in young basketball players. Sixteen players were recruited and assigned either to a plyometric + basketball training group (PT) or basketball training group (BT). All players trained twice per week, but the PT + BT followed a 6-week plyometric program implemented within basketball practice, whereas the BT followed regular practice. The star excursion balance test (SEBT) at 8 directions (anterior, A; anteromedial, AM; anterolateral, AL; medial, M; lateral, L; posterior, P; posteromedial, PM; and posterolateral, PL) was measured before and after the 6-week period. The PT group induced significant improvement (p ≤ 0.05) and small to moderate effect size in the SEBT (A = 0.95, AM = 0.62, AL = 0.61, M = 0.36, L = 0.47, P = 0.27, PM = 0.25, PL = 0.24). No significant improvements were found in the BT group. Also, there were significant differences between groups in all directions except PM and PL. An integrated plyometric program within the regular basketball practice can lead to significant improvements in SEBT and consequently PC. It can be recommended that strength and conditioning professionals use PT to enhance the athletes' joint awareness and PC to reduce possible future injuries in the lower extremity.

An Impact Study of the Design of Exergaming Parameters on Body Intensity from Objective and Gameplay-Based Player Experience Perspectives, Based on Balance Training Exergame

PubMed Central

2013-01-01

Kinect-based exergames allow players to undertake physical exercise in an interactive manner with visual stimulation. Previous studies focused on investigating physical fitness based on calories or heart rate to ascertain the effectiveness of exergames. However, designing an exergame for specific training purposes, with intensity levels suited to the needs and skills of the players, requires the investigation of motion performance to study player experience. This study investigates how parameters of a Kinect-based exergame, combined with balance training exercises, influence the balance control ability and intensity level the player can tolerate, by analyzing both objective and gameplay-based player experience, and taking enjoyment and difficulty levels into account. The exergame tested required participants to maintain their balance standing on one leg within a posture frame (PF) while a force plate evaluated the player's balance control ability in both static and dynamic gaming modes. The number of collisions with the PF depended on the frame's travel time for static PFs, and the leg-raising rate and angle for dynamic PFs. In terms of center of pressure (COP) metrics, significant impacts were caused by the frame's travel time on MDIST-AP for static PFs, and the leg-raising rate on MDIST-ML and TOTEX for dynamic PFs. The best static PF balance control performance was observed with a larger frame offset by a travel time of 2 seconds, and the worst performance with a smaller frame and a travel time of 1 second. The best dynamic PF performance was with a leg-raising rate of 1 second at a 45-degree angle, while the worst performance was with a rate of 2 seconds at a 90-degree angle. The results demonstrated that different evaluation methods for player experience could result in different findings, making it harder to study the design of those exergames with training purposes based on player experience. PMID:23922716

The Emergence of Relationship-based Cooperation.

PubMed

Xu, Bo; Wang, Jianwei

2015-11-16

This paper investigates the emergence of relationship-based cooperation by coupling two simple mechanisms into the model: tie strength based investment preference and homophily assumption. We construct the model by categorizing game participants into four types: prosocialists (players who prefers to invest in their intimate friends), antisocialists (players who prefer to invest in strangers), egoists (players who never cooperate) and altruists (players who cooperate indifferently with anyone). We show that the relationship-based cooperation (prosocialists) is favored throughout the evolution if we assume players of the same type have stronger ties than different ones. Moreover, we discover that strengthening the internal bonds within the strategic clusters further promotes the competitiveness of prosocialists and therefore facilitates the emergence of relationship-based cooperation in our proposed scenarios. The robustness of the model is also tested under different strategy updating rules and network structures. The results show that this argument is robust against the variations of initial conditions and therefore can be considered as a fundamental theoretical framework to study relationship-based cooperation in reality.

The Emergence of Relationship-based Cooperation

NASA Astrophysics Data System (ADS)

Xu, Bo; Wang, Jianwei

2015-11-01

This paper investigates the emergence of relationship-based cooperation by coupling two simple mechanisms into the model: tie strength based investment preference and homophily assumption. We construct the model by categorizing game participants into four types: prosocialists (players who prefers to invest in their intimate friends), antisocialists (players who prefer to invest in strangers), egoists (players who never cooperate) and altruists (players who cooperate indifferently with anyone). We show that the relationship-based cooperation (prosocialists) is favored throughout the evolution if we assume players of the same type have stronger ties than different ones. Moreover, we discover that strengthening the internal bonds within the strategic clusters further promotes the competitiveness of prosocialists and therefore facilitates the emergence of relationship-based cooperation in our proposed scenarios. The robustness of the model is also tested under different strategy updating rules and network structures. The results show that this argument is robust against the variations of initial conditions and therefore can be considered as a fundamental theoretical framework to study relationship-based cooperation in reality.

The Emergence of Relationship-based Cooperation

PubMed Central

Xu, Bo; Wang, Jianwei

2015-01-01

This paper investigates the emergence of relationship-based cooperation by coupling two simple mechanisms into the model: tie strength based investment preference and homophily assumption. We construct the model by categorizing game participants into four types: prosocialists (players who prefers to invest in their intimate friends), antisocialists (players who prefer to invest in strangers), egoists (players who never cooperate) and altruists (players who cooperate indifferently with anyone). We show that the relationship-based cooperation (prosocialists) is favored throughout the evolution if we assume players of the same type have stronger ties than different ones. Moreover, we discover that strengthening the internal bonds within the strategic clusters further promotes the competitiveness of prosocialists and therefore facilitates the emergence of relationship-based cooperation in our proposed scenarios. The robustness of the model is also tested under different strategy updating rules and network structures. The results show that this argument is robust against the variations of initial conditions and therefore can be considered as a fundamental theoretical framework to study relationship-based cooperation in reality. PMID:26567904

Caught on the Web

ERIC Educational Resources Information Center

Isakson, Carol

2006-01-01

A podcast is essentially a radio program that can be downloaded for enjoyment. Its content includes radio broadcasts, lectures, walking tours, and student-created audio projects. Most are in the standard MP3 file format that can be played on a computer, MP3 player, PDA, or newer CD or DVD players. This article presents resources for learning about…

Effect of age on anthropometric and physical performance measures in professional baseball players.

PubMed

Mangine, Gerald T; Hoffman, Jay R; Fragala, Maren S; Vazquez, Jose; Krause, Matthew C; Gillett, Javair; Pichardo, Napoleon

2013-02-01

The purpose of this study was to investigate age-related changes in anthropometric and performance variables in professional baseball players. Baseball players (n = 1,157) from several professional baseball organizations were categorized into 7 cohorts based upon age. All adolescent athletes were categorized as age group 1 (AG1), whereas the next 5 groups (AG2-AG6) consisted of players 20-22, 23-25, 26-28, 29-31, and 31-34 years, respectively. The final group (AG7) comprised athletes ≥35 years. All performance assessments were part of the athlete's normal preseason training camp testing routine. Field assessments were used to analyze lower-body power, speed, agility, grip strength, and body composition. The players were heaviest between the ages of 29 and 31 (AG5), and their body mass in that age group was 10.1% (p = 0.004) greater than that of AG1. A 7.0% increase (p = 0.000) in lean body mass occurred between AG1 and AG5. No differences in 10-yd sprint times or agility were seen across any age group or position. A 2.0 seconds (p = 0.001) slower run time for the 300-yd shuttle was seen between AG4 and AG5 for all positions combined. Elevations in grip strength were seen at AG4 compared with AG1 (p = 0.001) and AG2 (p = 0.007) for all positions combined. No other differences were noted. Lower-body power was increased for all positions combined from AG1 to AG3 (p = 0.007). This pattern was similar to that observed in position players, but a 12.4% decrease (p = 0.024) in VJMP was seen between AG7 and AG5 in pitchers. Results of this study indicate that lower-body power is maintained in baseball players until the age of 29-31, whereas speed, agility, and grip strength are maintained in players able to play past the age of 35 years. Age-related differences observed in this study suggest that athletes focus on their strength and conditioning programs to extend the length of their professional careers.

Adaptive Automation Design and Implementation

DTIC Science & Technology

2015-09-17

Study : Space Navigator This section demonstrates the player modeling paradigm, focusing specifically on the response generation section of the player ...human-machine system, a real-time player modeling framework for imitating a specific person’s task performance, and the Adaptive Automation System...Model . . . . . . . . . . . . . . . . . . . . . . . 13 Clustering-Based Real-Time Player Modeling . . . . . . . . . . . . . . . . . . . . . . 15 An

Background estimation and player detection in badminton video clips using histogram of pixel values along temporal dimension

NASA Astrophysics Data System (ADS)

Peng, Yahui; Ma, Xiao; Gao, Xinyu; Zhou, Fangxu

2015-12-01

Computer vision is an important tool for sports video processing. However, its application in badminton match analysis is very limited. In this study, we proposed a straightforward but robust histogram-based background estimation and player detection methods for badminton video clips, and compared the results with the naive averaging method and the mixture of Gaussians methods, respectively. The proposed method yielded better background estimation results than the naive averaging method and more accurate player detection results than the mixture of Gaussians player detection method. The preliminary results indicated that the proposed histogram-based method could estimate the background and extract the players accurately. We conclude that the proposed method can be used for badminton player tracking and further studies are warranted for automated match analysis.

Improving International-Level Chess Players' Performance with an Acceptance-Based Protocol: Preliminary Findings

ERIC Educational Resources Information Center

Ruiz, Francisco J.; Luciano, Carmen

2012-01-01

This study compared an individual, 4-hr intervention based on acceptance and commitment therapy (ACT) versus a no-contact control condition in improving the performance of international-level chess players. Five participants received the brief ACT protocol, with each matched to another chess player with similar characteristics in the control…

Understanding Player Activity in a Game-Based Virtual Learning Environment

ERIC Educational Resources Information Center

Boyer, David Matthew

2011-01-01

This study examines player activity in a game-based virtual learning environment as a means toward evaluating instructional and game design. By determining the goals embedded in project development and the availability and structure of in-game activities, the first part of this research highlights opportunities for players to engage with learning…

Player Load, Acceleration, and Deceleration During Forty-Five Competitive Matches of Elite Soccer.

PubMed

Dalen, Terje; Ingebrigtsen, Jørgen; Ettema, Gertjan; Hjelde, Geir Havard; Wisløff, Ulrik

2016-02-01

The use of time-motion analysis has advanced our understanding of position-specific work rate profiles and the physical requirements of soccer players. Still, many of the typical soccer activities can be neglected, as these systems only examine activities measured by distance and speed variables. This study used triaxial accelerometer and time-motion analysis to obtain new knowledge about elite soccer players' match load. Furthermore, we determined acceleration/deceleration profiles of elite soccer players and their contribution to the players' match load. The data set includes every domestic home game (n = 45) covering 3 full seasons (2009, 2010, and 2011) for the participating team (Rosenborg FC), and includes 8 central defenders (n = 68), 9 fullbacks (n = 83), 9 central midfielders (n = 70), 7 wide midfielders (n = 39), and 5 attackers (A, n = 50). A novel finding was that accelerations contributed to 7-10% of the total player load for all player positions, whereas decelerations contributed to 5-7%. Furthermore, the results indicate that other activities besides the high-intensity movements contribute significantly to the players' total match workload. Therefore, motion analysis alone may underestimate player load because many high-intensity actions are without a change in location at the pitch or they are classified as low-speed activity according to current standards. This new knowledge may help coaches to better understand the different ways players achieve match load and could be used in developing individualized programs that better meet the "positional physical demands" in elite soccer.

The Use of Performance Based Funding in a Sport Organization: A Case Study of the United States Olympic Committee

DTIC Science & Technology

2009-08-01

programs has intrigued me since I was a freshman water polo player at the United States Air Force Academy1. At that time, the Academy’s Athletic...on- field performance? 7     Need for the Study There is a wealth of information regarding performance-based funding systems and their...wide variety of sport organizations from team 9     sports like basketball and baseball to individual sports like swimming and track and field

Effects of the performance level and the FIFA "11" injury prevention program on the injury rate in Italian male amateur soccer players.

PubMed

Gatterer, H; Ruedl, G; Faulhaber, M; Regele, M; Burtscher, M

2012-02-01

Soccer is characterized by high injury rates that necessitate interventions for its reduction. The "11" is a multi-modal preventive program that was developed to reduce injury rate. However, outcomes on the effectiveness of the program are not unambiguous and data for the largest group at risk (i.e., male adult amateur players) are missing. The study aims to assess the injury rate in male adult amateur soccer players of different levels and to evaluate the effectiveness of the prevention program the "11". Three amateur soccer teams participated in the study during the first round of a competition season. Two teams played at a regional level (6th Italian league) and one team at a provincial level (7th Italian league). The regional league is of a higher skill level compared to the provincial league. Duration and frequency of training and match sessions and the occurrence of time-loss injuries were recorded. One team of the 6th league performed an injury prevention program. The total injury rate for the intervention and the control team in the 6th league was 3.3 (CI 0.7-5.9) and 4.3 (CI 1.3-7.3) injuries/1000 h, respectively (P=0.841). The 6th league control team tended to have a lesser injury rate compared to the 7th league team (P=0.081). The relative risk was 2 fold higher in the 7th compared to the 6th league team (P=0.0285 one tailed). Present results show that injury rate in amateur soccer depended rather on the skill level than the prevention program. In this study the prevention program the "11" was not shown to be highly effective in soccer player of intermediate level (i.e., 6th Italian league).

Learning Experiences of Gifted Young String Players in the Taiwan Milieu

ERIC Educational Resources Information Center

Liu, Chia-Hui

2008-01-01

The purpose of this study was to investigate the development of the learning experiences of gifted young string players in Taiwan. Nine musicians under the age of 40, who had been accepted into music programs for the gifted, were invited to discuss their experiences and the development of their careers. Thorough interviews were conducted and then…

Audubon Wildlife Adventures. Grizzly Guidebook. School Edition.

ERIC Educational Resources Information Center

National Audubon Society, Washington, DC.

This program introduces the young computer players to the world of the grizzly bear, the largest land carnivore in North America. Through a series of four interactive stories, players learn of the bear's habits and human activities that have brought it close to extinction. Playing the part of a park ranger, a research biologist or a natural…

Mediators effecting moderate-to-vigorous physical activity and inactivity for girls from an intervention program delivered in an organised youth sports setting.

PubMed

Guagliano, Justin M; Lonsdale, Chris; Rosenkranz, Richard R; Parker, Philip D; Agho, Kingsley E; Kolt, Gregory S

2015-11-01

The objective of this study was to test whether coaches' physical activity levels, contextual variables, and coaches' behavioural variables mediated the effect of an intervention on female basketball players' moderate-to-vigorous physical activity (MVPA) and inactivity in an organised youth sport (OYS) setting. Randomised controlled trial Data for the current study were derived from a two-armed, parallel-group randomised controlled trial. This study ran over the course of a 5-day OYS basketball program in 2 sports centres in Sydney, Australia. A convenience sample of 76 female players and 8 coaches were recruited. Coaches allocated to the intervention condition attended 2 coach education sessions, where strategies to increase MVPA and decrease inactivity were taught. There was a significant effect between changes in coach MVPA and player MVPA (unstandardised regression coefficient [B] = 0.26, 95% CI = 0.14 to 0.38) which coincided with a significant indirect effect (B = 1.80, 95% CI = 0.85 to 2.85). There was also a significant effect between changes in coach inactivity and player inactivity (B = -0.23, 95% CI = -0.14 to -0.31), which coincided with a significant indirect effect (B = -3.20, 95% CI = -0.14 to -0.31). No significant indirect effects were found for lesson context and coaches' behaviours variables. Coaches' MVPA and inactivity significantly mediated the effect of the intervention on player MVPA and inactivity, respectively. Consequently, coaches' physical activity levels appear to be important for influencing their players' physical activity levels. Published by Elsevier Ltd.

The Effects of Frontal- and Sagittal-Plane Plyometrics on Change-of-Direction Speed and Power in Adolescent Female Basketball Players.

PubMed

McCormick, Brian T; Hannon, James C; Newton, Maria; Shultz, Barry; Detling, Nicole; Young, Warren B

2016-01-01

Plyometrics is a popular training modality for basketball players to improve power and change-of-direction speed. Most plyometric training has used sagittal-plane exercises, but improvements in change-of-direction speed have been greater in multi-direction programs. To determine the benefits of a 6-wk frontal-plane plyometric (FPP) training program compared with a 6-wk sagittal-plane plyometric (SPP) training program with regard to power and change-of-direction speed. Fourteen female varsity high school basketball players participated in the study. Multiple 2 × 2 repeated-measures ANOVAs were used to determine differences for the FPP and SPP groups from preintervention to postintervention on 4 tests of power and 2 tests of change-of-direction speed. There was a group main effect for time in all 6 tests. There was a significant group × time interaction effect in 3 of the 6 tests. The SPP improved performance of the countermovement vertical jump more than the FPP, whereas the FPP improved performance of the lateral hop (left) and lateral-shuffle test (left) more than the SPP. The standing long jump, lateral hop (right), and lateral-shuffle test (right) did not show a significant interaction effect. These results suggest that basketball players should incorporate plyometric training in all planes to improve power and change-of-direction speed.

Effect of Hip-Focused Injury Prevention Training for Anterior Cruciate Ligament Injury Reduction in Female Basketball Players: A 12-Year Prospective Intervention Study.

PubMed

Omi, Yorikatsu; Sugimoto, Dai; Kuriyama, Setsurou; Kurihara, Tomohisa; Miyamoto, Kenji; Yun, Songjo; Kawashima, Tatsuhiro; Hirose, Norikazu

2018-03-01

Programs to prevent anterior cruciate ligament (ACL) injuries in female basketball players are scarce. Also, ACL injury prevention training that focuses on hip joint function has not been reported. To determine the effectiveness of a hip-focused ACL injury prevention program in female basketball players. Cohort study; Level of evidence, 2. A prospective intervention study was conducted for 12 years. Incidence rates of ACL injuries were collected in the first 4 years (observation period) from college female basketball players. After the observation period, a hip-focused ACL injury prevention program was implemented for 8 years (intervention period). A total of 309 players (mean ± SD age, 19.6 ± 1.2 years; height, 163.7 ± 5.6 cm; weight, 59.1 ± 5.1 kg; body mass index, 22.0 ± 1.4) were tracked in the observation period and compared with 448 players (age, 19.6 ± 1.1 years; height, 162.6 ± 5.8 cm; weight, 58.0 ± 5.7 kg; body mass index, 21.9 ± 1.5) who participated in the intervention period. Athlete-exposures (AEs), ACL numbers and mechanisms of injury (MOIs), relative risk (RR), absolute risk reduction (ARR), numbers needed to treat (NNT), and compliance were analyzed. There were 16 ACL injuries (13 noncontact MOIs) in the 4-year observation period, whereas 9 ACL injuries (8 noncontact MOIs) were recorded in the 8-year intervention period. The overall ACL injury incidence was 0.25/1000 AEs in the 4-year observation period compared with 0.10/1000 AEs in the 8-year intervention period, respectively. Compared with the 4-year observation period, significant RR reduction was observed (0.38; 95% CI, 0.17-0.87; P = .017) with ARR and NNT of 0.032 (95% CI, 0.027-0.037) and 31.6 (95% CI, 27.1-37.7), respectively, in the 8-year intervention period. The noncontact ACL injury incidence was 0.21 per 1000 AEs during the 4-year observation period compared with 0.08/1000 AEs in the 8-year intervention period, which also showed significant RR reduction (0.37; 95% CI, 0.15-0.92; P = .026), with ARR and NNT of 0.024 (95% CI, 0.020-0.029) and 41.3 (95% CI, 34.6-51.3), respectively. The mean compliance rate during the intervention periods (8 years) was 89%. A hip-focused injury prevention program demonstrated significant reduction in the incidence of ACL injury in female collegiate basketball players.

Effects of Plyometric and Sprint Training on Physical and Technical Skill Performance in Adolescent Soccer Players.

PubMed

Sáez de Villarreal, Eduardo; Suarez-Arrones, Luis; Requena, Bernardo; Haff, Gregory G; Ferrete, Carlos

2015-07-01

To determine the influence of a short-term combined plyometric and sprint training (9 weeks) within regular soccer practice on explosive and technical actions of pubertal soccer players during the in-season. Twenty-six players were randomly assigned to 2 groups: control group (CG) (soccer training only) and combined group (CombG) (plyometric + acceleration + dribbling + shooting). All players trained soccer 4 times per week and the experimental groups supplemented the soccer training with a proposed plyometric-sprint training program for 40 minutes (2 days per weeks). Ten-meter sprint, 10-m agility with and without ball, CMJ and Abalakov vertical jump, ball-shooting speed, and Yo-Yo intermittent endurance test were measured before and after training. The experimental group followed a 9-week plyometric and sprint program (i.e., jumping, hurdling, bouncing, skipping, and footwork) implemented before the soccer training. Baseline-training results showed no significant differences between the groups in any of the variables tested. No improvement was found in the CG; however, meaningful improvement was found in all variables in the experimental group: CMJ (effect size [ES] = 0.9), Abalakov vertical jump (ES = 1.3), 10-m sprint (ES = 0.7-0.9), 10-m agility (ES = 0.8-1.2), and ball-shooting speed (ES = 0.7-0.8). A specific combined plyometric and sprint training within regular soccer practice improved explosive actions compared with conventional soccer training only. Therefore, the short-term combined program had a beneficial impact on explosive actions, such as sprinting, change of direction, jumping, and ball-shooting speed which are important determinants of match-winning actions in soccer performance. Therefore, we propose modifications to current training methodology for pubertal soccer players to include combined plyometric and speed training for athlete preparation in this sport.

Scapular resting position, shoulder pain and function in disabled athletes.

PubMed

Aytar, Aydan; Zeybek, Aslican; Pekyavas, Nihan Ozunlu; Tigli, Ayca Aytar; Ergun, Nevin

2015-10-01

Despite the fact that the number of disabled individuals participating in sports is increasing, there are only sparse reports in the literature concerning overuse injuries. The purpose of this study was to compare scapular resting position, shoulder pain, and function in wheelchair basketball, amputee soccer, and disabled table tennis players. Descriptive study. A total of 63 disabled players from amputee soccer, wheelchair basketball, and disabled table tennis participated in our study. Scapular resting position was taken as primary outcome; pain and function were taken as secondary outcome measurements. Scapular resting position was evaluated with Lateral Scapular Slide Test. Visual Analog Scale was used for evaluating shoulder pain intensity. Quick disabilities of the arm, shoulder, and hand questionnaire were used to assess upper extremity function. There was a significant difference in shoulder pain, function, and scapular resting position in all groups (p < 0.05). Paired comparisons between amputee soccer and wheelchair basketball players and also amputee soccer and disabled table tennis showed difference for all measurement parameters (p < 0.05). When the results are evaluated, it may be stated that amputee soccer players have better scapular resting position than other sports. Crutch usage may not negatively affect scapular resting position and perceived function as much as wheelchair usage. Exercise techniques for shoulder and resting position could be included in training programs of disabled athletes. Wheelchair/crutch usage is a risk, and special exercise techniques for shoulder and dyskinesis could be included in training programs to prevent injury. However, it may not just be important for wheelchair athletes, it may also be important for amputee soccer players. In particular, total upper extremity evaluations and exercises could be added within exercise programs. © The International Society for Prosthetics and Orthotics 2014.

Effects of in-season low-volume high-intensity plyometric training on explosive actions and endurance of young soccer players.

PubMed

Ramírez-Campillo, Rodrigo; Meylan, César; Alvarez, Cristian; Henríquez-Olguín, Carlos; Martínez, Cristian; Cañas-Jamett, Rodrigo; Andrade, David C; Izquierdo, Mikel

2014-05-01

Integrating specific training methods to improve explosive actions and endurance in youth soccer is an essential part of players' development. This study investigated the efficiency of short-term vertical plyometric training program within soccer practice to improve both explosive actions and endurance in young soccer players. Seventy-six players were recruited and assigned either to a training group (TG; n = 38; 13.2 ± 1.8 years) or a control group (CG; n = 38; 13.2 ± 1.8 years) group. All players trained twice per week, but the TG followed a 7-week plyometric program implemented within soccer practice, whereas the CG followed regular practice. Twenty-meter sprint time (20-m), Illinois agility test time, countermovement jump (CMJ) height, 20- (RSI20) and 40- (RSI40) cm drop jump reactive strength index, multiple 5 bounds distance (MB5), maximal kicking test for distance (MKD), and 2.4-km time trial were measured before and after the 7-week period. Plyometric training induced significant (p ≤ 0.05) and small to moderate standardized effect (SE) improvement in the CMJ (4.3%; SE = 0.20), RSI20 (22%; SE = 0.57), RSI40 (16%; SE = 0.37), MB5 (4.1%; SE = 0.28), Illinois agility test time (-3.5%, SE = -0.26), MKD (14%; SE = 0.53), 2.4-km time trial (-1.9%; SE = -0.27) performances but had a trivial and nonsignificant effect on 20-m sprint time (-0.4%; SE = -0.03). No significant improvements were found in the CG. An integrated vertical plyometric program within the regular soccer practice can substitute soccer drills to improve most explosive actions and endurance, but horizontal exercises should also be included to enhance sprinting performance.

Effects of a 6-week junior tennis conditioning program on service velocity.

PubMed

Fernandez-Fernandez, Jaime; Ellenbecker, Todd; Sanz-Rivas, David; Ulbricht, Alexander; Ferrautia, Alexander

2013-01-01

This study examined the effects of a 6-week strength-training program on serve velocity in youth tennis players. Thirty competitive healthy and nationally ranked male junior tennis players (13 years of age) were randomly and equally divided into control and training groups. The training group performed 3 sessions (60-70 min) weekly for 6 weeks, comprising core strength, elastic resistance and medicine ball exercises. Both groups (control and training) also performed a supervised stretching routine at the end of each training session, during the 6 week intervention. Service velocity, service accuracy and shoulder internal/external rotation were assessed initially and at the end of the 6-week conditioning program for both, control and training groups. There was a significant improvement in the serve velocity for the training group (p = 0. 0001) after the intervention, whereas in the control group there were no differences between pre and post-tests (p = 0.29). Serve accuracy was not affected in the training group (p = 0.10), nor in the control group (p = 0.15). Shoulder internal/external rotation ROM significantly improved in both groups, training (p = 0.001) and control (p = 0.0001). The present results showed that a short- term training program for young tennis players, using minimum equipment and effort, can result in improved tennis performance (i.e., serve velocity) and a reduction in the risk of a possible overuse injury, reflected by an improvement in shoulder external/internal range of motion. Key PointsA short-term training program for young tennis players, using minimum equipment and effort, can result in improved tennis performance and a reduction in the risk of a possible overuse injury, reflected by an improvement in shoulder external/internal range of motionA combination of core stabilization, elastic resistance exercises, and upper body plyometric exercises (i.e., medicine ball throws), focussing on the primary muscle groups and stabilizers involved in tennis specific movement patterns, could be appropriate for development tennis playersStretching exercises are recommended in the cool-down phase following matches or training sessions.

Effects of A 6-Week Junior Tennis Conditioning Program on Service Velocity

PubMed Central

Fernandez-Fernandez, Jaime; Ellenbecker, Todd; Sanz-Rivas, david; Ulbricht, Alexander; Ferrautia, lexander

2013-01-01

This study examined the effects of a 6-week strength-training program on serve velocity in youth tennis players. Thirty competitive healthy and nationally ranked male junior tennis players (13 years of age) were randomly and equally divided into control and training groups. The training group performed 3 sessions (60-70 min) weekly for 6 weeks, comprising core strength, elastic resistance and medicine ball exercises. Both groups (control and training) also performed a supervised stretching routine at the end of each training session, during the 6 week intervention. Service velocity, service accuracy and shoulder internal/external rotation were assessed initially and at the end of the 6-week conditioning program for both, control and training groups. There was a significant improvement in the serve velocity for the training group (p = 0. 0001) after the intervention, whereas in the control group there were no differences between pre and post-tests (p = 0.29). Serve accuracy was not affected in the training group (p = 0.10), nor in the control group (p = 0.15). Shoulder internal/external rotation ROM significantly improved in both groups, training (p = 0.001) and control (p = 0.0001). The present results showed that a short- term training program for young tennis players, using minimum equipment and effort, can result in improved tennis performance (i.e., serve velocity) and a reduction in the risk of a possible overuse injury, reflected by an improvement in shoulder external/internal range of motion. Key Points A short-term training program for young tennis players, using minimum equipment and effort, can result in improved tennis performance and a reduction in the risk of a possible overuse injury, reflected by an improvement in shoulder external/internal range of motion A combination of core stabilization, elastic resistance exercises, and upper body plyometric exercises (i.e., medicine ball throws), focussing on the primary muscle groups and stabilizers involved in tennis specific movement patterns, could be appropriate for development tennis players Stretching exercises are recommended in the cool-down phase following matches or training sessions. PMID:24149801

Performance enhancement effects of Fédération Internationale de Football Association's "The 11+" injury prevention training program in youth futsal players.

PubMed

Reis, Ivan; Rebelo, António; Krustrup, Peter; Brito, João

2013-07-01

To evaluate if Fédération Internationale de Football Association's "The 11+" injury prevention program improves physical fitness and technical performance in youth futsal players. Randomized cohort study. Futsal club. Thirty-six futsal players (17.3 ± 0.7 years). Players were randomized to an intervention group (n = 18) or a control group (n = 18). Intervention group performed "The 11+" twice per week for 12 weeks. Isokinetic testing to access maximal quadriceps (Q) and hamstring (H) strength, vertical jump (squat jump, SJ; countermovement jump, CMJ), 5-m and 30-m sprint, agility, slalom, and balance performances were also measured. Intervention group increased (P < 0.05) quadriceps concentric (14.7%-27.3%) and hamstrings concentric (9.3%-13.3%) and eccentric (12.7%) peak torque. Intervention group improved functional H:Q ratio by 1.8% to 8.5% (P < 0.05). Intervention group improved (P < 0.05) SJ (13.8%) and CMJ (9.9%) and 5-m and 30-m sprint (8.9% and 3.3%, respectively), agility (4.7%), and slalom (4.8%) performances. Intervention group also improved balance, by decreasing the number of falls by 30% in the nondominant limb. No changes were observed in control group. The results suggest that 'The 11+' can be used as an effective conditioning means for improving physical fitness and technical performance of youth futsal players.

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.

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

Effect of core stability training on throwing velocity in female handball players.

PubMed

Saeterbakken, Atle H; van den Tillaar, Roland; Seiler, Stephen

2011-03-01

The purpose was to study the effect of a sling exercise training (SET)-based core stability program on maximal throwing velocity among female handball players. Twenty-four female high-school handball players (16.6 ± 0.3 years, 63 ± 6 kg, and 169 ± 7 cm) participated and were initially divided into a SET training group (n = 14) and a control group (CON, n = 10). Both groups performed their regular handball training for 6 weeks. In addition, twice a week, the SET group performed a progressive core stability-training program consisting of 6 unstable closed kinetic chain exercises. Maximal throwing velocity was measured before and after the training period using photocells. Maximal throwing velocity significantly increased 4.9% from 17.9 ± 0.5 to 18.8 ± 0.4 m·s in the SET group after the training period (p < 0.01), but was unchanged in the control group (17.1 ± 0.4 vs. 16.9 ± 0.4 m·s). These results suggest that core stability training using unstable, closed kinetic chain movements can significantly improve maximal throwing velocity. A stronger and more stable lumbopelvic-hip complex may contribute to higher rotational velocity in multisegmental movements. Strength coaches can incorporate exercises exposing the joints for destabilization force during training in closed kinetic chain exercises. This may encourage an effective neuromuscular pattern and increase force production and can improve a highly specific performance task such as throwing.

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.

Outcomes After Lumbar Disc Herniation in the National Basketball Association.

PubMed

Minhas, Shobhit V; Kester, Benjamin S; Hsu, Wellington K

2016-01-01

Professional basketball players are at risk for lumbar disc herniation (LDH), yet the evidence guiding treatment after operative or nonoperative management of this condition in the National Basketball Association (NBA) is limited. NBA players with LDH will have different performance outcomes based on treatment type. Case-control study. Level 4. Athletes in the NBA with an LDH were identified through team injury reports, transaction records, and public sports archives. A 1:2 case-control study was performed in which LDH players and players without LDH were matched for player variables. Statistical analysis was employed to compare pre- and postindex season performance (games played and player efficiency rating [PER]) and career longevity between test subjects and controls in the operatively treated (OT) and nonoperatively treated (NOT) cohorts. A total of 61 NBA players with LDH were included, of whom 34 underwent discectomy and 27 were managed nonoperatively. Return-to-play (RTP) rates did not differ between NOT and OT players (77.8% vs. 79.4%). When compared with controls, OT players played significantly fewer games and had a lower PER than controls during the first postoperative season, but no difference was seen 2 and 3 years after surgery, with no difference in postoperative career length. In contrast, no difference in games played or PER was seen between NOT players and controls, although NOT players played significantly fewer postindex seasons. NBA players have a high RTP rate regardless of type of treatment for LDH; however, postindex performance differs between surgically and nonoperatively managed patients when compared with players without an LDH. However, further studies with a larger sample size are required for more definitive recommendations. There is a high RTP rate after LDH in the NBA, although postindex performance may differ based on operative versus nonoperative treatment. © 2015 The Author(s).

Portraits of the Changes, the Players, and the Contexts. A Study of Dissemination Efforts Supporting School Improvement. People, Policies, and Practices: Examining the Chain of School Improvement, Volume II.

ERIC Educational Resources Information Center

Loucks, Susan F.; And Others

Based on a local site sample of 146 school districts, this volume (the second in a series of 10) describes school improvement efforts supported by 4 different federal strategies and representative programs: interpersonal linkage of validated practices (National Diffusion Network), commercial distribution (Bureau of Education for the Handicapped…

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.

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

Market niche analysis in the casino gaming industry.

PubMed

Dandurand, L

1990-03-01

This article discusses the nature of market niche analysis in the casino gaming industry. It presents four approaches for conducting market niche analysis. An an example of one approach, the Las Vegas Visitor Profile Study is used to identify a premium niche in the Las Vegas Slot Target Market. A detailed examination of the premium niche profile provides a description of the typical premium slot player. The description of the typical premium player leads to hypotheses regarding needs (the unique preference set) of the premium player. An analysis of the unique preference set suggests an appropriate enhanced marketing program.

N-player mosquito net game: individual and social rationality in the misuse of insecticide-treated nets.

PubMed

Honjo, Keita; Satake, Akiko

2014-02-07

Many governmental and non-governmental organizations have distributed insecticide-treated nets (ITNs) to malaria endemic areas, which contributed to the reduction of malaria deaths. However, some people in malaria endemic areas used ITNs for alternative purposes such as fishery and agriculture. It is unclear why people threatened by malaria misuse ITNs. Here we develop a N-player mosquito net game, and theoretically show that the misuse of ITNs might be underpinned by individual and social rationality. In the mosquito net game, each player uses ITNs for malaria prevention or alternative purposes. The proper ITN use decreases the probability of malaria infection, while the improper ITN use increases the player's labor productivity. Each player's expected payoff is influenced by other players' strategies. We found that the misuse of ITNs can be a Pareto efficient Nash equilibrium. The maximum number of players using ITNs for malaria prevention is limited by insecticidal effectiveness of ITNs and extra income from ITN misuse. Furthermore, we found that players in a low-income community are attracted to the misuse of ITNs even if the probability of malaria infection is high. Introduction of a tax on ITN misuse was shown to be effective to motivate the players to use ITNs for malaria prevention. Our results demonstrate that understanding decision making of people in malaria endemic areas is essential to design more effective malaria control programs. © 2013 Published by Elsevier Ltd. All rights reserved.

Improvements of the Penalty Avoiding Rational Policy Making Algorithm and an Application to the Othello Game

NASA Astrophysics Data System (ADS)

Miyazaki, Kazuteru; Tsuboi, Sougo; Kobayashi, Shigenobu

The purpose of reinforcement learning is to learn an optimal policy in general. However, in 2-players games such as the othello game, it is important to acquire a penalty avoiding policy. In this paper, we focus on formation of a penalty avoiding policy based on the Penalty Avoiding Rational Policy Making algorithm [Miyazaki 01]. In applying it to large-scale problems, we are confronted with the curse of dimensionality. We introduce several ideas and heuristics to overcome the combinational explosion in large-scale problems. First, we propose an algorithm to save the memory by calculation of state transition. Second, we describe how to restrict exploration by two type knowledge; KIFU database and evaluation funcion. We show that our learning player can always defeat against the well-known othello game program KITTY.

A network-based dynamical ranking system for competitive sports

NASA Astrophysics Data System (ADS)

Motegi, Shun; Masuda, Naoki

2012-12-01

From the viewpoint of networks, a ranking system for players or teams in sports is equivalent to a centrality measure for sports networks, whereby a directed link represents the result of a single game. Previously proposed network-based ranking systems are derived from static networks, i.e., aggregation of the results of games over time. However, the score of a player (or team) fluctuates over time. Defeating a renowned player in the peak performance is intuitively more rewarding than defeating the same player in other periods. To account for this factor, we propose a dynamic variant of such a network-based ranking system and apply it to professional men's tennis data. We derive a set of linear online update equations for the score of each player. The proposed ranking system predicts the outcome of the future games with a higher accuracy than the static counterparts.

Differences in Degree Aspirations and Attainment Outcomes between Football or Basketball Players and Other Intercollegiate Athletes. ASHE Annual Meeting Paper.

ERIC Educational Resources Information Center

Briggs, Charlotte L.

Using data from the Cooperative Institutional Research Program of students who were college freshmen in 1986 and responded to a follow-up survey in 1990, this study examined differences in degree aspirations and attainment between intercollegiate football or basketball players (N=158) and other intercollegiate athletes (N=801). Although there were…

The Influence of Trainee Gaming Experience and Computer Self-Efficacy on Learner Outcomes of Videogame-Based Learning Environments

DTIC Science & Technology

2005-06-01

videogame-based training environment. In this research, 413 participants played a first-person-perspective videogame that began with a single- player ...section to introduce game-specific tasks, followed by a multi- player section where participants formed small teams to conduct several collaborative...with over four million registered players . In Janurary 2004, America’s Army was used during a four-day inter-semester game- based training exercise at

Nonoperative Management, Rehabilitation, and Functional and Clinical Progression of Osteitis Pubis/Pubic Bone Stress in Professional Soccer Players: A Case Series.

PubMed

McAleer, Stephen S; Lippie, Ed; Norman, Darcy; Riepenhof, Helge

2017-09-01

Study Design Case series. Background Pubic bone stress (PBS) is a common acute or chronic response of the pelvis in sports where sprinting, kicking, twisting, and cutting are the dominant movements. There are few nonoperative rehabilitation strategies for the condition reported in the literature, and the outcome of conservative treatment has not been documented. Case Description Five professional and academy soccer players complaining of pubic symphysis pain, confirmed as PBS on magnetic resonance imaging and objective assessment, were treated with a nonoperative rehabilitation program that featured functional and clinical objective markers as progression criteria. Interventions in the acute phase included pharmacological and physical therapeutic modalities to reduce pain initially. Rehabilitation management focused on improving range of motion at the hips and thorax, adductor strengthening, trunk and lumbopelvic stability, gym-based strength training, and field-based rehabilitation and conditioning. Clinical follow-up was performed at least 8 months following return to play. Outcomes All players demonstrated reduced or resolved pain, increased adductor squeeze strength, and return to pain-free training and match play. Return-to-training time averaged 40.6 days (range, 30-60 days) and return to play averaged 49.4 days (range, 38-72 days) within the 5 players. At final follow-up (mean, 29.6 months; range, 16-33 months), there had been no recurrences. Discussion This report of 5 cases suggests that a nonoperative protocol, using clinical and functional progression criteria, may be successful in rehabilitating athletes with PBS for return to sport within 11 weeks. Level of Evidence Therapy, level 4. J Orthop Sports Phys Ther 2017;47(9):683-690. Epub 3 Aug 2017. doi:10.2519/jospt.2017.7314.

Context-dependent player's movement interpretation: application to adaptive game development

NASA Astrophysics Data System (ADS)

Picard, Francois; Estraillier, Pascal

2010-02-01

Video games are more and more controlled by the real movements of the player. However, the player is constrained by the system devices, imposing a limited vocabulary of actions associated with a set of unnatural movements. To introduce more entertaining video games to players, a component-based architecture is proposed. It has been acknowledged as the starting point for the development of adaptive applications based on the hypothesis of a high level dialogue between the system and the player. The system adaptability relies on interpretation mechanisms of the player behaviors. These behaviors are defined through the representation of the real movements of the player who freely interacts with the 3D elements composing an immersive virtual environment, following a given game scenario. The efficient interpretation of the player movements relies on the introduction in the system of the management of the scene's context. The contextual information not only helps to determine the true meaning of an observed behavior but also makes the system to adapt its processes regarding this interpretation, while managing its hardware and software resources efficiently. A commercial motion capture interface has been enhanced by the elaboration of such a system.

Learning Loops--Interactions between Guided Reflection and Experience-Based Learning in a Serious Game Activity

ERIC Educational Resources Information Center

Cowley, B.; Heikura, T.; Ravaja, N.

2013-01-01

In a study on experience-based learning in serious games, 45 players were tested for topic comprehension by a questionnaire administered before and after playing the single-player serious game Peacemaker (Impact Games 2007). Players were divided into two activity conditions: 20 played a 1-h game with a 3-min half-time break to complete an affect…

A prospective study of concussions among National Hockey League players during regular season games: the NHL-NHLPA Concussion Program

PubMed Central

Benson, Brian W.; Meeuwisse, Willem H.; Rizos, John; Kang, Jian; Burke, Charles J.

2011-01-01

Background In 1997, the National Hockey League (NHL) and NHL Players’ Association (NHLPA) launched a concussion program to improve the understanding of this injury. We explored initial postconcussion signs, symptoms, physical examination findings and time loss (i.e., time between the injury and medical clearance by the physician to return to competitive play), experienced by male professional ice-hockey players, and assessed the utility of initial postconcussion clinical manifestations in predicting time loss among hockey players. Methods We conducted a prospective case series of concussions over seven NHL regular seasons (1997–2004) using an inclusive cohort of players. The primary outcome was concussion and the secondary outcome was time loss. NHL team physicians documented post-concussion clinical manifestations and recorded the date when a player was medically cleared to return to play. Results Team physicians reported 559 concussions during regular season games. The estimated incidence was 1.8 concussions per 1000 player-hours. The most common postconcussion symptom was headache (71%). On average, time loss (in days) increased 2.25 times (95% confidence interval [CI] 1.41–3.62) for every subsequent (i.e., recurrent) concussion sustained during the study period. Controlling for age and position, significant predictors of time loss were postconcussion headache (p < 0.001), low energy or fatigue (p = 0.01), amnesia (p = 0.02) and abnormal neurologic examination (p = 0.01). Using a previously suggested time loss cut-point of 10 days, headache (odds ratio [OR] 2.17, 95% CI 1.33–3.54) and low energy or fatigue (OR 1.72, 95% CI 1.04–2.85) were significant predictors of time loss of more than 10 days. Interpretation Postconcussion headache, low energy or fatigue, amnesia and abnormal neurologic examination were significant predictors of time loss among professional hockey players. PMID:21502355

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

Body Size of Male Youth Soccer Players: 1978-2015.

PubMed

Malina, Robert M; Figueiredo, António J; Coelho-E-Silva, Manuel J

2017-10-01

Studies of the body size and proportions of athletes have a long history. Comparisons of athletes within specific sports across time, though not extensive, indicate both positive and negative trends. To evaluate secular variation in heights and weights of male youth soccer players reported in studies between 1978 and 2015. Reported mean ages, heights, and weights of male soccer players 9-18 years of age were extracted from the literature and grouped into two intervals: 1978-99 and 2000-15. A third-order polynomial was fitted to the mean heights and weights across the age range for each interval, while the Preece-Baines model 1 was fitted to the grand means of mean heights and mean weights within each chronological year to estimate ages at peak height velocity and peak weight velocity for each time interval. Third-order polynomials applied to all data points and estimates based on the Preece-Baines model applied to grand means for each age group provided similar fits. Both indicated secular changes in body size between the two intervals. Secular increases in height and weight between 1978-99 and 2000-15 were especially apparent between 13 and 16 years of age, but estimated ages at peak height velocity (13.01 and 12.91 years) and peak weight velocity (13.86 and 13.77 years) did not differ between the time intervals. Although the body size of youth soccer players increased between 1978-99 and 2000-15, estimated ages at peak height velocity and peak weight velocity did not change. The increase in height and weight likely reflected improved health and nutritional conditions, in addition to the selectivity of soccer reflected in systematic selection and retention of players advanced in maturity status, and exclusion of late maturing players beginning at about 12-13 years of age. Enhanced training programs aimed at the development of strength and power are probably an additional factor contributing to secular increases in body weight.

Leg Stiffness in Female Soccer Players: Intersession Reliability and the Fatiguing Effects of Soccer-Specific Exercise.

PubMed

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

2017-11-01

De Ste Croix, MBA, Hughes, JD, Lloyd, RS, Oliver, JL, and Read, PJ. Leg stiffness in female soccer players: intersession reliability and the fatiguing effects of soccer-specific exercise. J Strength Cond Res 31(11): 3052-3058, 2016-Low levels of leg stiffness and reduced leg stiffness when fatigue is present compromise physical performance and increase injury risk. The purpose of this study was to (a) determine the reliability of leg stiffness measures obtained from contact mat data and (b) explore age-related differences in leg stiffness after exposure to a soccer-specific fatigue protocol in young female soccer players. Thirty-seven uninjured female youth soccer players divided into 3 subgroups based on chronological age (under 13 [U13], under 15 [U15], and under 17 [U17] year-olds) volunteered to participate in the study. After baseline data collection, during which relative leg stiffness, contact time, and flight time were collected, participants completed an age-appropriate soccer-specific fatigue protocol (SAFT). Upon completion of the fatigue protocol, subjects were immediately retested. Intersession reliability was acceptable and could be considered capable of detecting worthwhile changes in performance. Results showed that leg stiffness decreased in the U13 year-olds, was maintained in the U15 age group, and increased in the U17 players. Contact times and flight times did not change in the U13 and U15 year-olds, but significantly decreased and increased, respectively, in the U17 age group. The data suggest that age-related changes in the neuromuscular control of leg stiffness are present in youth female soccer players. Practitioners should be aware of these discrepancies in neuromuscular responses to soccer-specific fatigue, and should tailor training programs to meet the needs of individuals, which may subsequently enhance performance and reduce injury risk.

National Collegiate Athletic Association Division I football players' perceptions of women in the athletic training room using a role congruity framework.

PubMed

O'Connor, Caitlin; Grappendorf, Heidi; Burton, Laura; Harmon, Sandra M; Henderson, Angela C; Peel, Judy

2010-01-01

Previous researchers have demonstrated that male and female athletes feel more comfortable with treatment by a same-sex athletic trainer for sex-specific injuries and conditions. To address football players' comfort with care provided by same-sex and opposite-sex athletic trainers for sex-specific and non-sex-specific injuries and conditions through the lens of role congruity theory. Cross-sectional study for the quantitative data and qualitative study for the qualitative data. Two National Collegiate Athletic Association Division I Football Bowl Series university football programs. Male football players within the 2 university programs. We replicated existing methods and an existing survey to address male football players' comfort levels. Additionally, an open-ended question was used to determine male football players' perceptions of female athletic trainers. Paired-samples t tests were conducted to identify differences between the responses for the care given by a male athletic trainer and for the care given by a female athletic trainer. Three categories were analyzed: general medical conditions, psychological conditions, and sex-specific injuries. The qualitative data were coded and analyzed using content analysis. Male football players were more comfortable with treatment by a male athletic trainer (mean = 3.61 +/- 1.16) for sex-specific injuries and conditions than they were with treatment by a female athletic trainer (mean = 2.82 +/- 1.27; P < .001). No significant results were found for comfort with overall psychological conditions, although a female athletic trainer was preferred over a male athletic trainer for the treatment of depression (mean = 3.71 +/- 1.07 versus mean = 3.39 +/- 1.16, respectively; P < .001). Qualitative data provided support for role congruity theory. Both quantitative and qualitative evidence were provided for the support of role congruity theory.

Characterization of static balance abilities in elite soccer players by playing position and age.

PubMed

Pau, Massimiliano; Ibba, Gianfranco; Leban, Bruno; Scorcu, Marco

2014-01-01

In this study, we investigated the static balance of adult and adolescent elite soccer players to understand how expertise and playing position influence postural control. Seventy-one national level players were tested using a force platform to acquire Center-of-Pressure (COP) data in uni- and bipedal stance and calculate sway area (SA), COP path length, velocity and displacements. The results show significant differences in postural sway related to age and playing position only for single-limb stance. In particular, midfielders exhibited significantly lower values of SA with respect to defenders (-48%, p = 0.001) and the under-15 players exhibited SA 42-64% higher than all the others (p = 0.001). In the light of planning training or rehabilitation programs specific for each player's role and age, sway measurements may supply useful, objective and reliable information only for the unipedal test as the bipedal standing appears not challenging enough to let differences in balance abilities emerge.

Lower extremity balance is improved at time of return to throwing in baseball players after an ulnar collateral ligament reconstruction when compared to pre-operative measurements.

PubMed

Hannon, Joseph; Garrison, J Craig; Conway, John

2014-05-01

/ Lower extremity balance deficits have been shown to lead to altered kinematics and increased injury risk in lower extremity athletes. The purpose of this study was to compare lower extremity balance in baseball players with an ulnar collateral ligament (UCL) tear pre-operatively and post-operatively at the beginning of the pre-return to throwing program stage of rehabilitation (3 months). Thirty-three competitive high school and collegiate male baseball players (18.5 ± 3.2) with a diagnosed UCL tear volunteered for the study. Of the 33 baseball players 29 were pitchers, 1 was a catcher, and 3 were infielders. Participants were seen pre-operatively and at 3 months post operatively. This 3 month point was associated with a follow-up visit to the orthopedic surgeon and subsequent release to begin the pre-return to throwing mark for baseball players following their surgery. Following surgery, each participant followed a standard UCL protocol which included focused lower extremity balance and neuromuscular control exercises. Participants were tested for single leg balance using the Y-Balance Test™ - Lower Quadrant (YBT-LQ) on both their lead and stance limbs. YBT-LQ composite scores were calculated for the stance and lead limbs pre- and post-operatively and compared over time. Paired t-tests were used to calculate differences between time 1 and time 2 (p < 0.05). Baseball players with diagnosed UCL tears demonstrated significant balance deficits on their stance (p < .001) and lead (p = .009) limbs prior to surgery compared to balance measures at the 3-month follow up (Stance Pre-Op = 89.4 ± 7.5%; Stance 3 Month = 94.9 ± 9.5%) (Lead Pre-Op = 90.2 ± 6.7%; Lead 3 Month = 93.6 ± 7.2%). Based on the results of this study, lower extremity balance is altered in baseball players with UCL tears prior to surgery. Statistically significant improvements were seen and balance measures improved at the time of return to throwing. Level 2b.

The Influence of Playing Experience and Position on Injury Risk in NCAA Division I College Football Players.

PubMed

McCunn, Robert; Fullagar, Hugh H K; Williams, Sean; Halseth, Travis J; Sampson, John A; Murray, Andrew

2017-11-01

American football is widely played by college student-athletes throughout the United States; however, the associated injury risk is greater than in other team sports. Numerous factors likely contribute to this risk, yet research identifying these risk factors is limited. The present study sought to explore the relationship between playing experience and position on injury risk in NCAA Division I college football players. Seventy-six male college student-athletes in the football program of an American NCAA Division I university participated. Injuries were recorded over 2 consecutive seasons. Players were characterized based on college year (freshman, sophomore, junior, or senior) and playing position. The effect of playing experience and position on injury incidence rates was analyzed using a generalized linear mixed-effects model, with a Poisson distribution, log-linear link function, and offset for hours of training exposure or number of in-game plays (for training and game injuries, respectively). The overall rates of non-time-loss and time-loss game-related injuries were 2.1 (90% CI: 1.8-2.5) and 0.6 (90% CI: 0.4-0.8) per 1000 plays, respectively. The overall rates of non-time-loss and time-loss training-related injuries were 26.0 (90% CI: 22.6-29.9) and 7.1 (90% CI: 5.9-8.5) per 1000 h, respectively. During training, seniors and running backs displayed the greatest risk. During games, sophomores, juniors, and wide receivers were at greatest risk. Being aware of the elevated injury risk experienced by certain player groups may help coaches make considered decisions related to training design and player selection.

Does Visual Performance Influence Head Impact Severity Among High School Football Athletes?

PubMed

Schmidt, Julianne D; Guskiewicz, Kevin M; Mihalik, Jason P; Blackburn, J Troy; Siegmund, Gunter P; Marshall, Stephen W

2015-11-01

To compare the odds of sustaining moderate and severe head impacts, rather than mild, between high school football players with high and low visual performance. Prospective quasi-experimental. Clinical Research Center/On-field. Thirty-seven high school varsity football players. Athletes completed the Nike SPARQ Sensory Station visual assessment before the season. Head impact biomechanics were captured at all practices and games using the Head Impact Telemetry System. Each player was classified as either a high or low performer using a median split for each of the following visual performance measures: visual clarity, contrast sensitivity, depth perception, near-far quickness, target capture, perception span, eye-hand coordination, go/no go, and reaction time. We computed the odds of sustaining moderate and severe head impacts against the reference odds of sustaining mild head impacts across groups of high and low performers for each of the visual performance measures. Players with better near-far quickness had increased odds of sustaining moderate [odds ratios (ORs), 1.27; 95% confidence intervals (CIs), 1.04-1.56] and severe head impacts (OR, 1.45; 95% CI, 1.05-2.01) as measured by Head Impact Technology severity profile. High and low performers were at equal odds on all other measures. Better visual performance did not reduce the odds of sustaining higher magnitude head impacts. Visual performance may play less of a role than expected for protecting against higher magnitude head impacts among high school football players. Further research is needed to determine whether visual performance influences concussion risk. Based on our results, we do not recommend using visual training programs at the high school level for the purpose of reducing the odds of sustaining higher magnitude head impacts.

The machine intelligence Hex project

NASA Astrophysics Data System (ADS)

Chalup, Stephan K.; Mellor, Drew; Rosamond, Fran

2005-12-01

Hex is a challenging strategy board game for two players. To enhance students’ progress in acquiring understanding and practical experience with complex machine intelligence and programming concepts we developed the Machine Intelligence Hex (MIHex) project. The associated undergraduate student assignment is about designing and implementing Hex players and evaluating them in an automated tournament of all programs developed by the class. This article surveys educational aspects of the MIHex project. Additionally, fundamental techniques for game programming as well as specific concepts for Hex board evaluation are reviewed. The MIHex game server and possibilities of tournament organisation are described. We summarise and discuss our experiences from running the MIHex project assignment over four consecutive years. The impact on student motivation and learning benefits are evaluated using questionnaires and interviews.

Activity profiles of the Australian female netball team players during international competition: implications for training practice.

PubMed

Fox, Aaron; Spittle, Michael; Otago, Leonie; Saunders, Natalie

2013-01-01

In elite sport, to remain competitive at the international level, it is critical to understand the game demands on players to ensure sport specific training programmes are designed for optimal athlete preparation and conditioning. In netball, recent research examining the activity patterns of players at the elite level is lacking, with only one study undertaken on this level of competition in the past 30 years. Therefore, the aim of this study was to provide coaches with up to date knowledge of player activity patterns as a basis for the design of optimal sport specific training programmes. The Australian female netball team were analysed using video footage of three international test matches. Player activity was categorised into five movement and eight game-based activities; and further classified as work or rest. Results suggest that differences in the current game exist when compared to the previous analysis. Positional differences were also found with regard to player activity confirming the need for an individualised component of training based on player position.

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.

Injuries in professional Rugby Union.

PubMed

Targett, S G

1998-10-01

To document injury rates in professional rugby players in the Rugby Super 12 competition and to act as a pilot study for future studies of rugby injuries. Prospective longitudinal study encompassing the 1997 Super 12 rugby season. A New Zealand Super 12 rugby squad. 25 professional rugby players (replacement players were used for unavailable players, so although 30 different players were used during the season, there were only 25 in the squad at any one time). An "injury" was defined as something that prevented a player from taking part in two training sessions, from playing the next week, or something requiring special medical treatment (suturing or special investigations). An injury was "significant" if it prevented the player from being able to play one week after sustaining it (that is, if it made the player miss the next match). The overall injury rate was 120/1000 player hours. The rate of significant injuries was 45/1000 player hours. Those playing the position of "forward" had a higher overall injury rate than other players, but there was no difference in significant injury rate between the forwards and the backs. Injuries that caused players to miss game time occurred almost exclusively during the pre-season program or in the final third of the season. The majority of injuries were musculo-tendinous sprains or strains. The phase of play responsible for the majority of injuries was the tackle. The most frequently injured body part was the head and face. No catastrophic injuries occurred during the study period. Injury rates increase with increasing grade of rugby, injury rates in the Super 12 competition being higher than in first grade rugby. There is very little quality data on rugby injuries, and the few studies available use different methods of data collection and injury definition. There is a pressing need for the collection of accurate ongoing epidemiological data on injuries in rugby.

Perceived motivational factors for female football players during rehabilitation after sports injury – a qualitative interview study

PubMed Central

Hildingsson, Malin; Fitzgerald, Ulrika Tranaeus; Alricsson, Marie

2018-01-01

Compliance with a rehabilitation program is significant among athletes following a sports injury. It is also one of the main factors that influence the rehabilitation process; moreover, the outcome is also influenced by the athlete’s motivation. It is primarily an autonomous motivation, resulting in rehabilitation adherence. The aim of this study was to investigate the perceived motivation of female football players during rehabilitation after a sports injury and the extent to which these motivating factors were autonomous. Qualitative interviews, based on a semistructured interview guide with injured female football players undergoing rehabilitation, were analyzed using content analysis. The motivational factors that were described were their set goals, social support as well as external and internal pressures during rehabilitation. The perceived autonomy varied somewhat but overall, they experienced external motivation; therefore, the behavior was not entirely self-determined. Results are expected to provide a better understanding of women football players’ motivation in relation to their rehabilitation; hence, physiotherapists and coaches who are part of the rehabilitation process can contribute by increasing the autonomous motivation, thus, improving the compliance and outcome of the rehabilitation. PMID:29740552

Physical demands of game-based training drills in women's team handball.

PubMed

Luteberget, Live S; Trollerud, Hege P; Spencer, Matt

2018-03-01

Game-based training drills are popular in team sports. This study compared two game-based training conditions and official matches in team handball. Thirty-one women players wore inertial measurement units in five training sessions and five official matches. In training, 3vs3 and 6vs6 game-based training conditions were performed with a 5-min duration. PlayerLoad™ and high-intensity events (HIEs; >2.5 m · s -1 ) were extracted from the raw data. Data were analysed using magnitude-based inferences and reported with effect sizes (ESs). PlayerLoad™ · min -1 from all positions combined was 11.37 ± 0.49 (mean ± 90% confidence limits) and 9.71 ± 0.3 for the 3vs3 and 6vs6 conditions, respectively. Backs (ES: 1.63), wings (ES: 1.91), and pivots (ES: 1.58) had greater PlayerLoad™ in 3vs3 than 6vs6. Substantially greater HIE · min -1 in 3vs3 occurred for all positions. There was substantially greater PlayerLoad™ · min -1 in 3vs3 and 6vs6 than match play for backs, wings, and pivots. Wings (ES: 1.95), pivots (ES: 0.70), and goalkeeper (ES: 1.13) had substantially greater HIE · min -1 in 3vs3 than match play. This study shows greater PlayerLoad™ and HIE in 3vs3 than 6vs6. Both game-based training conditions investigated in this study provide an overload in overall PlayerLoad™; however, additional exercises might be needed to overload HIE, especially for backs and pivots.

Soccer injuries in female youth players: comparison of injury surveillance by certified athletic trainers and internet.

PubMed

Schiff, Melissa A; Mack, Christopher D; Polissar, Nayak L; Levy, Marni R; Dow, Sara P; O'Kane, John W

2010-01-01

Few authors have evaluated sports injury-surveillance systems that use parental, Internet-based surveys for data collection. To determine whether certified athletic trainers (ATs) and parental, Internet-based surveys provided comparable data for identifying soccer injuries. Prospective feasibility cohort study. A soccer association in Seattle, Washington. Eighty female youth soccer players, ages 12 to 14 years. We compared the data provided by ATs attending 1 soccer practice per week with a weekly soccer-parent, Internet-based system. We measured athlete-exposure hours (AEHs) for each player. We compared injury rates reported by ATs only, Internet-based surveys only, and both systems combined. We evaluated the 2 surveillance systems for agreement on injured body region and laterality of injury using the kappa statistic. For ATs only, Internet-based surveys only, and both systems combined, we found acute injury rates of 3.0 per 1000 AEHs, 3.9 per 1000 AEHs, and 4.7 per 1000 AEHs and overuse injury rates of 1.0 per 1000 AEHs, 2.9 per 1000 AEHs, and 2.9 per 1000 AEHs, respectively. Players sustained 27 acute injuries (44% ankle, 11% knee, 11% hip) reported by at least 1 of the 2 systems, with 63% reported by ATs and 85% by Internet-based survey. Players sustained 17 overuse injuries (35% knee, 29% lower leg) reported by either system, with 35% reported by ATs and 100% by Internet-based survey. Among players for whom we had both ATs' and Internet-based survey injury data, body region injured and laterality had very good agreement (kappa = 0.73 to 1.0). The injury rate based on the weekly parental, Internet-based survey was similar to the rate based on the ATs' reporting and had comparable classifications of injured body region and laterality of injury.

Effect of Training on Physiological and Biochemical Variables of Soccer Players of Different Age Groups

PubMed Central

Manna, Indranil; Khanna, Gulshan Lal; Chandra Dhara, Prakash

2010-01-01

Purpose To find out the effect of training on selected physiological and biochemical variables of Indian soccer players of different age groups. Methods A total of 120 soccer players volunteered for the study, were divided (n = 30) into 4 groups: (i) under 16 years (U16), (ii) under 19 years (U19), (iii) under 23 years (U23), (iv) senior (SR). The training sessions were divided into 2 phases (a) Preparatory Phase (PP, 8 weeks) and (b) Competitive Phase (CP, 4 weeks). The training program consisted of aerobic, anaerobic and skill development, and were completed 4 hrs/day; 5 days/week. Selected physiological and biochemical variables were measured at zero level (baseline data, BD) and at the end of PP and CP. Results A significant increase (P < 0.05) in lean body mass (LBM), VO2max, anaerobic power, grip and back strength, urea, uric acid and high density lipoprotein cholesterol (HDL-C); and a significant decrease (P < 0.05) in body fat, hemoglobin (Hb), total cholesterol (TC), triglyceride (TG) and low density lipoprotein cholesterol (LDL-C) were detected in some groups in PP and CP phases of the training when compare to BD. However, no significant change was found in body mass and maximal heart rate of the players after the training program. Conclusion This study would provide useful information for training and selection of soccer players of different age groups. PMID:22375187

The Impact of a Sports Vision Training Program in Youth Field Hockey Players

PubMed Central

Schwab, Sebastian; Memmert, Daniel

2012-01-01

The aim of this study was to investigate whether a sports vision training program improves the visual performance of youth male field hockey players, ages 12 to 16 years, after an intervention of six weeks compared to a control group with no specific sports vision training. The choice reaction time task at the D2 board (Learning Task I), the functional field of view task (Learning Task II) and the multiple object tracking (MOT) task (Transfer Task) were assessed before and after the intervention and again six weeks after the second test. Analyzes showed significant differences between the two groups for the choice reaction time task at the D2 board and the functional field of view task, with significant improvements for the intervention group and none for the control group. For the transfer task, we could not find statistically significant improvements for either group. The results of this study are discussed in terms of theoretical and practical implications. Key pointsPerceptual training with youth field hockey playersCan a sports vision training program improve the visual performance of youth male field hockey players, ages 12 to 16 years, after an intervention of six weeks compared to a control group with no specific sports vision training?The intervention was performed in the “VisuLab” as DynamicEye® SportsVision Training at the German Sport University Cologne.We ran a series of 3 two-factor univariate analysis of variance (ANOVA) with repeated measures on both within subject independent variables (group; measuring point) to examine the effects on central perception, peripheral perception and choice reaction time.The present study shows an improvement of certain visual abilities with the help of the sports vision training program. PMID:24150071

The Impact of a Concussion-U Educational Program on Knowledge of and Attitudes about Concussion.

PubMed

Eagles, Matthew E; Bradbury-Squires, David J; Powell, Maria F; Murphy, Justin R; Campbell, Graeme D; Maroun, Falah B

2016-09-01

The diagnosis of a sports-related concussion is often dependent on the athlete self-reporting their symptoms. It has been suggested that improving youth athlete knowledge and attitudes toward concussion may increase self-reporting behaviour. The objective of this study was to determine if a novel Concussion-U educational program improves knowledge of and attitudes about concussion among a cohort of elite male Bantam and Midget AAA hockey players. Fifty-seven male Bantam and Midget AAA-level hockey players (mean age=14.52±1.13 years) were recruited from the local community. Each participant completed a modified version of the Rosenbaum Concussion Knowledge and Attitudes Survey-Student Version immediately before and after a Concussion-U educational presentation. Follow-up sessions were arranged 4 to 6 months after the presentation, and assessed retention of knowledge and attitude changes. Forty-three players completed all three surveys. Concussion knowledge and attitude scores significantly (p<0.01) increased from pre- to post-presentation by 12.79 and 8.41%, respectively. At long-term follow-up, knowledge levels remained significantly (p<0.01) higher than baseline by 8.49%. Mean attitude scores were also increased at follow-up; however, this increase was not statistically significant. A Concussion-U educational program led to an immediate improvement in concussion knowledge and attitudes among elite male Bantam and Midget AAA hockey players. Increased knowledge was maintained at long-term follow-up, but improved attitude was not. Future studies should investigate whether similar educational programs influence symptom reporting and concussion incidence. In addition, they should focus on how to maintain improved concussion attitudes.

Parasocial interaction with my avatar: effects of interdependent self-construal and the mediating role of self-presence in an avatar-based console game, Wii.

PubMed

Jin, Seung-A Annie; Park, Namkee

2009-12-01

The "self" concept has grown increasingly important in interactive media environments. This study investigated self-related processes in an avatar-based game console, Wii. A key feature of the Wii is its motion-sensing capability that empowers players to manipulate and interact with items on-screen via movement. The present study examined the effects of video game players' self-construal on parasocial interaction with their avatars and feelings of self-presence. In this study, parasocial interaction was operationally defined as the extent of game players' interpersonal involvement with their avatar and the extent to which game players perceive themselves as interacting with the avatar. Self-presence was defined as the degree to which video game players feel as if their avatar on the screen were their real self. Based on an experiment, the study discovered that game players with high interdependent self-construal showed closer parasocial interaction and higher level of self-presence than those with low interdependent self-construal. Results also showed that self-presence mediated the effects of interdependent self-construal on the parasocial relationship with game players' avatars. Thus, the study discovered an important individual difference factor, interdependent self-construal, affecting the degree to which people form a parasocial relationship with their virtual self that is visually manifested in the form of an avatar. In addition, the present study added empirical evidence about the mediating role played by self-presence in avatar-based video games.

Differential Learning as a Key Training Approach to Improve Creative and Tactical Behavior in Soccer

ERIC Educational Resources Information Center

Santos, Sara; Coutinho, Diogo; Gonçalves, Bruno; Schöllhorn, Wolfgang; Sampaio, Jaime; Leite, Nuno

2018-01-01

Purpose: The aim of this study was to identify the effects of a differential-learning program, embedded in small-sided games, on the creative and tactical behavior of youth soccer players. Forty players from under-13 (U13) and under-15 (U15) were allocated into control and experimental groups and were tested using a randomized pretest to posttest…

Understanding mismatches in body size, speed and power among adolescent rugby union players.

PubMed

Krause, Lyndon M; Naughton, Geraldine A; Denny, Greg; Patton, Declan; Hartwig, Tim; Gabbett, Tim J

2015-05-01

With adolescent sport increasingly challenged by mismatches in size, new strategies are important to maximize participation. The objectives were to (1) improve the understanding of mismatches in physical size, speed and power in adolescent rugby union players, (2) explore associations between size and performance with demographic, playing-history, and injury profiles, and (3) explore the applicability of existing criteria for age/body mass-based dispensation (playing-down) strategies. Cross-sectional study. Four hundred and eighty-five male community rugby union players were recruited from three Australian states selected to represent community-based U12, U13, U14 and U15 players. Body mass, stature, speed (10, 30, and 40 m sprints) and lower-leg power (relative peak power and relative peak force) were measured. Independent student t-tests, linear regressions and Chi square analyses were undertaken. Mean values in age groups for size, speed and power masked considerable overlap in the ranges within specific age groups of adolescent rugby players. Only a small proportion of players (approximately 5%) shared the highest and lowest tertiles for speed, relative peak power and body mass. Physical size was not related to injury. The mean body mass of current community rugby union players was above the 75th percentile on normative growth-charts. The notion that bigger, faster, and more powerful characteristics occur simultaneously in adolescent rugby players was not supported in the present study. Current practices in body mass-based criteria for playing down an age group lack a sufficient evidence for decision-making. Dispensation solely based on body mass may not address mismatch in junior rugby union. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Game theory based models to analyze water conflicts in the Middle Route of the South-to-North Water Transfer Project in China.

PubMed

Wei, Shouke; Yang, Hong; Abbaspour, Karim; Mousavi, Jamshid; Gnauck, Albrecht

2010-04-01

This study applied game theory based models to analyze and solve water conflicts concerning water allocation and nitrogen reduction in the Middle Route of the South-to-North Water Transfer Project in China. The game simulation comprised two levels, including one main game with five players and four sub-games with each containing three sub-players. We used statistical and econometric regression methods to formulate payoff functions of the players, economic valuation methods (EVMs) to transform non-monetary value into economic one, cost-benefit Analysis (CBA) to compare the game outcomes, and scenario analysis to investigate the future uncertainties. The validity of game simulation was evaluated by comparing predictions with observations. The main results proved that cooperation would make the players collectively better off, though some player would face losses. However, players were not willing to cooperate, which would result in a prisoners' dilemma. Scenarios simulation results displayed that players in water scare area could not solve its severe water deficit problem without cooperation with other players even under an optimistic scenario, while the uncertainty of cooperation would come from the main polluters. The results suggest a need to design a mechanism to reduce the risk of losses of those players by a side payment, which provides them with economic incentives to cooperate. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Laterality related to the successive selection of Dutch national youth soccer players.

PubMed

Verbeek, Jan; Elferink-Gemser, Marije T; Jonker, Laura; Huijgen, Barbara C H; Visscher, Chris

2017-11-01

In the general population, estimates of left-foot preference are around 20%. In soccer, specific tasks create positional demands, requiring 40% of the players to be left-footed. Whether and how this is related to the selection of players is unknown. To examine the successive selection of soccer players for Dutch national youth teams in relation to foot preference, 280 youth players (age = 16.2 ± 1.08 years) were monitored from the U16 through the U19 teams over the last 5 years. No difference in successive selection between left- and right-footed players was found (p < 0.05). Regardless of foot preference, more than 50% of the selected players were deselected out of a national youth team after 2 years. On average, 31% of the national youth players were left-footed, which is higher than expected, based on population estimates (χ 2 (1) = 37.49, p < 0.001, w = 0.27). However, there was an under-representation of left-footed players, based on expected positional demands (i.e., attack, midfield, defence) (χ 2 (1) = 16.83, p < 0.001, w = 0.18). The conclusion is that left-foot preference increases the probability of selection in Dutch national youth soccer teams.

Does the FIFA 11+ Injury Prevention Program Reduce the Incidence of ACL Injury in Male Soccer Players?

PubMed

Silvers-Granelli, Holly J; Bizzini, Mario; Arundale, Amelia; Mandelbaum, Bert R; Snyder-Mackler, Lynn

2017-10-01

The FIFA 11+ injury prevention program has been shown to decrease the risk of soccer injuries in men and women. The program has also been shown to decrease time loss resulting from injury. However, previous studies have not specifically investigated how the program might impact the rate of anterior cruciate ligament (ACL) injury in male soccer players. The purpose of this study was to examine if the FIFA 11+ injury prevention program can (1) reduce the overall number of ACL injuries in men who play competitive college soccer and whether any potential reduction in rate of ACL injuries differed based on (2) game versus practice setting; (3) player position; (4) level of play (Division I or II); or (5) field type. This study was a prospective cluster randomized controlled trial, which was conducted in 61 Division I and Division II National Collegiate Athletic Association men's soccer teams over the course of one competitive soccer season. The FIFA 11+ is a 15- to 20-minute on-the-field dynamic warm-up program used before training and games and was utilized as the intervention throughout the entire competitive season. Sixty-five teams were randomized: 34 to the control group (850 players) and 31 to the intervention group (675 players). Four intervention teams did not complete the study and did not submit their data, noting insufficient time to complete the program, reducing the number for per-protocol analysis to 61. Compliance to the FIFA 11+ program, athletic exposures, specific injuries, ACL injuries, and time loss resulting from injury were collected and recorded using a secure Internet-based system. At the end of the season, the data in the injury surveillance system were crosshatched with each individual institution's internal database. At that time, the certified athletic trainer signed off on the injury collection data to confirm their accuracy and completeness. A lower proportion of athletes in the intervention group experienced knee injuries (25% [34 of 136]) compared with the control group (75% [102 of 136]; relative risk [RR], 0.42; 95% confidence interval [CI], 0.29-0.61; p < 0.001). When the data were stratified for ACL injury, fewer ACL injuries were reported in the intervention group (16% [three of 19]) compared with the control group (84% [16 of 19]), accounting for a 4.25-fold reduction in the likelihood of incurring ACL injury (RR, 0.236; 95% CI, 0.193-0.93; number needed to treat = 70; p < 0.001). With the numbers available, there was no difference between the ACL injury rate within the FIFA 11+ group and the control group with respect to game and practice sessions (games-intervention: 1.055% [three of 15] versus control: 1.80% [12 of 15]; RR, 0.31; 95% CI, 0.09-1.11; p = 0.073 and practices-intervention: 0% [zero of four] versus control: 0.60% [four of four]; RR, 0.14; 95% CI, 0.01-2.59; p = 0.186). With the data that were available, there were no differences in incidence rate (IR) or injury by player position for forwards (IR control = 0.339 versus IR intervention = 0), midfielders (IR control = 0.54 versus IR intervention = 0.227), defenders (IR control = 0.339 versus IR intervention = 0.085), and goalkeepers (IR control = 0.0 versus IR intervention = 0.0) (p = 0.327). There were no differences in the number of ACL injuries for the Division I intervention group (0.70% [two of nine]) compared with the control group (1.05% [seven of nine]; RR, 0.30; CI, 0.06-1.45; p = 0.136). However, there were fewer ACL injuries incurred in the Division II intervention group (0.35% [one of 10]) compared with the control group (1.35% [nine of 10]; RR, 0.12; CI, 0.02-0.93; p = 0.042). There was no difference between the number of ACL injuries in the control group versus in the intervention group that occurred on grass versus turf (Wald chi square [1] = 0.473, b = 0.147, SE = 0.21, p = 0.492). However, there were more ACL injuries that occurred on artificial turf identified in the control group (1.35% [nine of 10]) versus the intervention group (0.35% [one of 10]; RR, 0.14; 95% CI, 0.02-1.10; p = 0.049). This program, if implemented correctly, has the potential to decrease the rate of ACL injury in competitive soccer players. In addition, this may also enhance the development and dissemination of injury prevention protocols and may mitigate risk to athletes who utilize the program consistently. Further studies are necessary to analyze the cost-effectiveness of the program implementation and to analyze the efficacy of the FIFA 11+ in the female collegiate soccer cohort. Level I, therapeutic study.

Short-term Outcomes following Concussion in the NFL: An 11-year Retrospective Study of Player Release Rate and Financial Loss

PubMed Central

Ramkumar, Prem; Navarro, Sergio Michael

2017-01-01

Objectives: The primary goal of this study was to assess the short-term outcomes among National Football League (NFL) players following concussion in terms of: (1) DNP protocol activation, (2) release rate at one and three years, and (3) mean salary reduction. A secondary goal of the study was to stratify the post-concussive release rate by franchise and player position. Methods: NFL player transaction records and publicly available weekly injury reports from August 2005 to January 2016 for NFL players were analyzed. All players immediately sustaining recorded concussions were evaluated for a change to inactive or do-not-play (DNP) status. The one-year and three-year release rate following concussion was defined as any player transitioning to inactivation, retirement, free agency, or any failure to return for a successive season on the same team’s active roster after one or three years from the initial concussion. Student’s t-test was used to compare release rates between non-concussed and concussed players at one and three years. Mean salary reduction per year following concussion was calculated using publicly available player contracts. Additionally, franchise-level and position-based analyses of the release rate were performed. Results: Of the total 5,451 NFL players retrospectively analyzed over the 11-year period, 373 sustained publicly reported concussions resulting in DNP protocol activation. The release rate of the post-concussive versus non-concussive player was 26% vs. 20% at 1 year (p<0.01) and 31% vs. 19% at 3 years (p<0.01). After analyzing individual player contracts, the mean year-over-year change in contract value for concussed players after DNP protocol activation was an overall salary reduction of $760,000/year ± $2,380,000. Figure 1 depicts the tendency of each NFL franchise to release an athlete following concussion within one and three years. Table 1 reports a position-based analysis in terms of concussion rate, mean salary reduction, and NFL career longevity. Conclusion: Our retrospective study demonstrates that NFL concussions resulting in DNP protocol activation leads to a statistically greater release rate among concussed NFL players than non-concussed players. Released players suffered reduction in year-over-year accumulated earnings, and particular franchises tended to release concussed players more than others. Position-based Concussion Statistics of Players by DNP Activation, Salary Reduction, Career LengthPosition GroupDNP ConcussionsMean Salary Reduction ($/yr)Average Career Length (yrs)DB75 (20.1%)280,0007.0WR66 (17.7%)1,760,0007.3OL49 (13.1%)1,190,0005.5TE46 (12.3%)333,0007.7RB40 (10.7%)140,0005.1LB39 (10.5%)720,0004.9DL31 (8.3%)540,0007.0QB27 (7.2%)2,440,0007.3Total373760,0006.4

Outcomes After Lumbar Disc Herniation in the National Basketball Association

PubMed Central

Minhas, Shobhit V.; Kester, Benjamin S.; Hsu, Wellington K.

2016-01-01

Background: Professional basketball players are at risk for lumbar disc herniation (LDH), yet the evidence guiding treatment after operative or nonoperative management of this condition in the National Basketball Association (NBA) is limited. Hypothesis: NBA players with LDH will have different performance outcomes based on treatment type. Study Design: Case-control study. Level of Evidence: Level 4. Methods: Athletes in the NBA with an LDH were identified through team injury reports, transaction records, and public sports archives. A 1:2 case-control study was performed in which LDH players and players without LDH were matched for player variables. Statistical analysis was employed to compare pre- and postindex season performance (games played and player efficiency rating [PER]) and career longevity between test subjects and controls in the operatively treated (OT) and nonoperatively treated (NOT) cohorts. Results: A total of 61 NBA players with LDH were included, of whom 34 underwent discectomy and 27 were managed nonoperatively. Return-to-play (RTP) rates did not differ between NOT and OT players (77.8% vs 79.4%). When compared with controls, OT players played significantly fewer games and had a lower PER than controls during the first postoperative season, but no difference was seen 2 and 3 years after surgery, with no difference in postoperative career length. In contrast, no difference in games played or PER was seen between NOT players and controls, although NOT players played significantly fewer postindex seasons. Conclusion: NBA players have a high RTP rate regardless of type of treatment for LDH; however, postindex performance differs between surgically and nonoperatively managed patients when compared with players without an LDH. However, further studies with a larger sample size are required for more definitive recommendations. Clinical Relevance: There is a high RTP rate after LDH in the NBA, although postindex performance may differ based on operative versus nonoperative treatment. PMID:26502185

Prevalence of tinea pedis in professional and college soccer players versus non-athletes.

PubMed

Pickup, Tiffany L; Adams, Brian B

2007-01-01

To assess and compare the prevalence of tinea pedis among professional soccer players, college soccer players, and non-athletes. We sought to assess the prevalence of various risk factors and their association with tinea pedis among these different groups. Survey study. United States. Members of a United Soccer League (USL) professional team (N = 16), male (N = 16) and female (N = 14) NCAA soccer teams at a local college, and male (N = 15) and female (N = 15) non-athletes from a local medical school. All participants anonymously answered questions on their risk factors for tinea pedis and underwent physical and mycological examinations. Clinical exam, potassium hydroxide solution (KOH), and culture. Tinea pedis infected 69% professional soccer players (11 of 16) compared with 69% of male college soccer players (11 of 16) and 43% of female college soccer players (6 of 14), whereas non-athletes demonstrated significantly less tinea pedis (P < 0.001), including 20% of male non-athletes (3 of 15) and 0% of female non-athletes (0 of 15). These results indicate a need for improved primary prevention of tinea pedis among athletes. A preventive program involving education and coach participation is needed to target these individuals.

How the Iranian Football Coaches and Players Know About Doping?

PubMed Central

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

2015-01-01

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

Effects of the Skills4Genius sports-based training program in creative behavior

PubMed Central

Santos, Sara; Jiménez, Sergio; Sampaio, Jaime; Leite, Nuno

2017-01-01

Team Sports has been suggested as a suitable environment to investigate creative behavior. This study’s purpose was two-fold: first, it intended to identify the effects of the Skills4Genius sports-bases training program in thinking, motor, and in-game creative behavior in team sports. Second, it aimed to investigate the relationship between creative thinking and in-game creativity. Forty children from primary school were allocated into control (n = 18, age: 9.2±0.4) and experimental (n = 22, age: 9.5±0.7) groups. The experimental group participated in a five-month training program involving either creative thinking, diversification, physical literacy, and nonlinear pedagogy approaches (Skills4Genius). Variables in the study included: a) creative thinking; b) motor performance (vertical jump, speed, and agility); c) in-game individual creative behavior (attempts, fluency, and versatility); and d) in-game collective behavior (positional regularity). The results suggested that the Skills4Genius program fostered creative thinking, agility, and speed performance. Moreover, it stretched the in-game individual creative behavior mainly through the improvement of the attempts and versatility of the player’s actions. Lastly, it nurtured a better learning of the tactical principles, whereas the children were more coordinated with their teammates’ and opponents’ positioning. Additionally, this study presents a positive correlation linking creative thinking and in-game creative performance. These findings highlighted that creativity is facilitated while players become more thinking and game-skilled. Coaches and educators may apply this functional environment to inspire children’s disposition to move outside the box and trigger a creative spark in team sports players. Notwithstanding, the sports environment is ideally suited for fostering creative behavior, a higher-order disposition that will go on to differentiate the everyday life of a child. PMID:28231260

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 Effects of Comprehensive Warm-Up Programs on Proprioception, Static and Dynamic Balance on Male Soccer Players

PubMed Central

Daneshjoo, Abdolhamid; Mokhtar, Abdul Halim; Rahnama, Nader; Yusof, Ashril

2012-01-01

Purpose The study investigated the effects of FIFA 11+ and HarmoKnee, both being popular warm-up programs, on proprioception, and on the static and dynamic balance of professional male soccer players. Methods Under 21 year-old soccer players (n = 36) were divided randomly into 11+, HarmoKnee and control groups. The programs were performed for 2 months (24 sessions). Proprioception was measured bilaterally at 30°, 45° and 60° knee flexion using the Biodex Isokinetic Dynamometer. Static and dynamic balances were evaluated using the stork stand test and Star Excursion Balance Test (SEBT), respectively. Results The proprioception error of dominant leg significantly decreased from pre- to post-test by 2.8% and 1.7% in the 11+ group at 45° and 60° knee flexion, compared to 3% and 2.1% in the HarmoKnee group. The largest joint positioning error was in the non-dominant leg at 30° knee flexion (mean error value = 5.047), (p<0.05). The static balance with the eyes opened increased in the 11+ by 10.9% and in the HarmoKnee by 6.1% (p<0.05). The static balance with eyes closed significantly increased in the 11+ by 12.4% and in the HarmoKnee by 17.6%. The results indicated that static balance was significantly higher in eyes opened compared to eyes closed (p = 0.000). Significant improvements in SEBT in the 11+ (12.4%) and HarmoKnee (17.6%) groups were also found. Conclusion Both the 11+ and HarmoKnee programs were proven to be useful warm-up protocols in improving proprioception at 45° and 60° knee flexion as well as static and dynamic balance in professional male soccer players. Data from this research may be helpful in encouraging coaches or trainers to implement the two warm-up programs in their soccer teams. PMID:23251579

Robust Adaptive Dynamic Programming of Two-Player Zero-Sum Games for Continuous-Time Linear Systems.

PubMed

Fu, Yue; Fu, Jun; Chai, Tianyou

2015-12-01

In this brief, an online robust adaptive dynamic programming algorithm is proposed for two-player zero-sum games of continuous-time unknown linear systems with matched uncertainties, which are functions of system outputs and states of a completely unknown exosystem. The online algorithm is developed using the policy iteration (PI) scheme with only one iteration loop. A new analytical method is proposed for convergence proof of the PI scheme. The sufficient conditions are given to guarantee globally asymptotic stability and suboptimal property of the closed-loop system. Simulation studies are conducted to illustrate the effectiveness of the proposed method.

REHABILITATION AFTER HIP ARTHROSCOPY AND LABRAL REPAIR IN A HIGH SCHOOL FOOTBALL ATHLETE

PubMed Central

Kolber, Morey J.

2012-01-01

Study Design: Case Report Background: Femoral acetabular impingement (FAI) has been implicated in the etiology of acetabular labral tears. The rehabilitation of younger athletes following arthroscopic surgery for FAI and labral tears is often complex and multifactorial. A paucity of evidence exists to describe the rehabilitation of younger athletes who have undergone arthroscopic hip surgery. Case Presentation: This case report describes a four-phase rehabilitation program for a high school football player who underwent hip arthroscopy with a labral repair and chondroplasty. Outcomes: The player returned to training for football 16 weeks later and at the 4 month follow-up was pain free with no signs of FAI. Discussion: There is little evidence regarding the rehabilitation of younger athletes who undergo arthroscopic hip surgery. This case study described a four phase rehabilitation program for a high school football player who underwent hip arthroscopy and labral repair. The patient achieved positive outcomes with a full return to athletic activity and football. The overall success of these patients depends on the appropriate surgical procedure and rehabilitation program. Key Words: Femoral acetabular impingement (FAI), hip, hip impingement Level of evidence: 4-Case report PMID:22530192

Developing close combat behaviors for simulated soldiers using genetic programming techniques.

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

Pryor, Richard J.; Schaller, Mark J.

2003-10-01

Genetic programming is a powerful methodology for automatically producing solutions to problems in a variety of domains. It has been used successfully to develop behaviors for RoboCup soccer players and simple combat agents. We will attempt to use genetic programming to solve a problem in the domain of strategic combat, keeping in mind the end goal of developing sophisticated behaviors for compound defense and infiltration. The simplified problem at hand is that of two armed agents in a small room, containing obstacles, fighting against each other for survival. The base case and three changes are considered: a memory of positionsmore » using stacks, context-dependent genetic programming, and strongly typed genetic programming. Our work demonstrates slight improvements from the first two techniques, and no significant improvement from the last.« less

Injury risk is low among world-class volleyball players: 4-year data from the FIVB Injury Surveillance System

PubMed Central

Bere, Tone; Kruczynski, Jacek; Veintimilla, Nadège; Hamu, Yuichiro; Bahr, Roald

2015-01-01

Background Little is known about the rate and pattern of injuries in international volleyball competition. Objective To describe the risk and pattern of injuries among world-class players based on data from the The International Volleyball Federation (FIVB) Injury Surveillance System (ISS) (junior and senior, male and female). Methods The FIVB ISS is based on prospective registration of injuries by team medical staff during all major FIVB tournaments (World Championships, World Cup, World Grand Prix, World League, Olympic Games). This paper is based on 4-year data (September 2010 to November 2014) obtained through the FIVB ISS during 32 major FIVB events (23 senior and 9 junior). Results The incidence of time-loss injuries during match play was 3.8/1000 player hours (95% CI 3.0 to 4.5); this was greater for senior players than for junior players (relative risk: 2.04, 1.29 to 3.21), while there was no difference between males and females (1.04, 0.70 to 1.55). Across all age and sex groups, the ankle was the most commonly injured body part (25.9%), followed by the knee (15.2%), fingers/thumb (10.7%) and lower back (8.9%). Injury incidence was greater for centre players and lower for liberos than for other player functions; injury patterns also differed between player functions. Conclusions Volleyball is a very safe sport, even at the highest levels of play. Preventive measures should focus on acute ankle and finger sprains, and overuse injuries in the knee, lower back and shoulder. PMID:26194501

Comparison of chosen physical fitness characteristics of Turkish professional basketball players by division and playing position.

PubMed

Köklü, Yusuf; Alemdaroğlu, Utku; Koçak, Fatma Ünver; Erol, A Emre; Fındıkoğlu, Gülin

2011-12-01

The purpose of the present study was to compare chosen physical fitness characteristics of Turkish professional basketball players in different divisions (first and second division) and playing positions. Forty-five professional male basketball players (14 guards, 15 forwards, 16 centers) participated in this study voluntarily. For each player, anthropometric measurements were performed, as well as a multi-stage 20 m shuttle run, isokinetic leg strength, squat jump (SJ), countermovement jump (CMJ), 10-30 meter single-sprint and T-drill agility tests. The differences in terms of division were evaluated by independent t-test and the differences by playing position were evaluated by one-way ANOVA with Post Hoc Tukey test. First division players' CMJ measurements were significantly higher than those of second division players' (p≤0.05), whereas second division players' 10 m sprint times were significantly better than those of first division players' (p≤0.05). In addition, forwards and centers were significantly taller than guards. Centers were significantly heavier and their T-drill test performances were inferior to those of forwards and guards (p≤0.05). Moreover, guards had a significantly higher maximal oxygen uptake (VO2 max) than centers. Guards and forwards showed significantly better performance in the 10 and 30 m sprint tests than centers (p≤0.05). Forwards and centers had significantly better left leg flexor strength at 180°.s(-1)(p≤0.05). In conclusion, the findings of the present study indicated that physical performance of professional basketball players differed among guards, forwards and centers, whereas there were not significant differences between first and second division players. According to the present study, court positions have different demands and physical attributes which are specific to each playing position in professional basketball players. Therefore, these results suggest that coaches should tailor fitness programs according to specific positions on the court.

Evolution of cooperation by the introduction of the probabilistic peer-punishment based on the difference of payoff.

PubMed

Ohdaira, Tetsushi

2016-05-05

There are two types of costly punishment, i.e. peer-punishment and pool-punishment. While peer-punishment applies direct face to face punishment, pool-punishment is based on multi-point, collective interaction among group members. Regarding those two types of costly punishment, peer-punishment is especially considered to have the flaws that it lowers the average payoff of all players as well as pool-punishment does, and facilitates antisocial behaviour like retaliation of a defector on a cooperator. Here, this study proposes the new peer-punishment that punishment to an opponent player works at high probability when an opponent one is uncooperative, and the difference of payoff between a player and an opponent one becomes large in order to prevent such antisocial behaviour. It is natural to think that players of high payoff do not expect to punish others of lower payoff because they do not have any complaints regarding their economic wealth. The author shows that the introduction of the proposed peer-punishment increases both the number of cooperative players and the average payoff of all players in various types of topology of connections between players.

Evolution of cooperation by the introduction of the probabilistic peer-punishment based on the difference of payoff

PubMed Central

Ohdaira, Tetsushi

2016-01-01

There are two types of costly punishment, i.e. peer-punishment and pool-punishment. While peer-punishment applies direct face to face punishment, pool-punishment is based on multi-point, collective interaction among group members. Regarding those two types of costly punishment, peer-punishment is especially considered to have the flaws that it lowers the average payoff of all players as well as pool-punishment does, and facilitates antisocial behaviour like retaliation of a defector on a cooperator. Here, this study proposes the new peer-punishment that punishment to an opponent player works at high probability when an opponent one is uncooperative, and the difference of payoff between a player and an opponent one becomes large in order to prevent such antisocial behaviour. It is natural to think that players of high payoff do not expect to punish others of lower payoff because they do not have any complaints regarding their economic wealth. The author shows that the introduction of the proposed peer-punishment increases both the number of cooperative players and the average payoff of all players in various types of topology of connections between players. PMID:27146347

Evolution of cooperation by the introduction of the probabilistic peer-punishment based on the difference of payoff

NASA Astrophysics Data System (ADS)

Ohdaira, Tetsushi

2016-05-01

There are two types of costly punishment, i.e. peer-punishment and pool-punishment. While peer-punishment applies direct face to face punishment, pool-punishment is based on multi-point, collective interaction among group members. Regarding those two types of costly punishment, peer-punishment is especially considered to have the flaws that it lowers the average payoff of all players as well as pool-punishment does, and facilitates antisocial behaviour like retaliation of a defector on a cooperator. Here, this study proposes the new peer-punishment that punishment to an opponent player works at high probability when an opponent one is uncooperative, and the difference of payoff between a player and an opponent one becomes large in order to prevent such antisocial behaviour. It is natural to think that players of high payoff do not expect to punish others of lower payoff because they do not have any complaints regarding their economic wealth. The author shows that the introduction of the proposed peer-punishment increases both the number of cooperative players and the average payoff of all players in various types of topology of connections between players.

Mechanical, Hormonal and Psychological Effects of a Non-Failure Short-Term Strength Training Program in Young Tennis Players

PubMed Central

Sarabia, Jose Manuel; Fernandez-Fernandez, Jaime; Juan-Recio, Casto; Hernández-Davó, Hector; Urbán, Tomás; Moya, Manuel

2015-01-01

This study examined the effects of a 6-week non-failure strength training program in youth tennis players. Twenty tennis players (age: 15.0 ± 1 years, body height: 170.9 ± 5.1 cm, body mass: 63.3 ± 9.1 kg) were divided into experimental and control groups. Pre and post-tests included half squats, bench press, squat jumps, countermovement-jumps and side-ball throws. Salivary cortisol samples were collected, and the Profile of Mood States questionnaire was used weekly during an anatomical adaptation period, a main training period and after a tapering week. The results showed that, after the main training period, the experimental group significantly improved (p<0.05) in mean and peak power output and in the total number of repetitions during the half-squat endurance test; mean force, power and velocity in the half-squat power output test; Profile of Mood States (in total mood disturbance between the last week of the mean training period and the tapering week); and in squat-jump and countermovement-jump height. Moreover, significant differences were found between the groups at the post-tests in the total number of repetitions, mean and peak power during the half-squat endurance test, mean velocity in the half-squat power output test, salivary cortisol concentration (baselines, first and third week of the mean training period) and in the Profile of Mood States (in fatigue subscale: first and third week of the mean training period). In conclusion, a non-failure strength training protocol improved lower-limb performance levels and produced a moderate psychophysiological impact in youth elite tennis players, suggesting that it is a suitable program to improve strength. Such training protocols do not increase the total training load of tennis players and may be recommended to improve strength. PMID:25964812

Decision Making in Online Fantasy Sports Communities

ERIC Educational Resources Information Center

Smith, Brian; Sharma, Priya; Hooper, Paula

2006-01-01

This paper describes the forms of knowledge used by players of fantasy sports, games where players create ideal sports teams and compete to accumulate points based on professional athletes' statistical performances. Messages from a discussion forum associated with a popular fantasy basketball game were analyzed to understand how players described…

Economic and environmental benefits of reducing standby power lossin DVD/VCD players and copiers in China

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

Lin, Jiang; Li, Tienan; Li, Aizhen

With the popularization of household electrical appliances and the rapid development of office automation and networking, a huge number of consumer electronic devices, computers, copiers, and fax machines have been put into use in China over the last two decades. These products almost all use a certain amount of standby power--the power that is consumed when a device is connected but not performing its primary function. The rapid growth of standby energy consumption due to these products--and the consequent environmental problems--has attracted more and more attentions from researchers and from many government and international agencies. Numerous countries have developed policiesmore » and measures to restrict and reduce standby energy consumption (US EPA, 2004, IEA, 2001, and GEEA, 2004). However, standby energy consumption is still a new concept for Chinese consumers and the phenomenon of ''unconscious waste of energy'' is still very common in the people's daily life and work. With the goal of reducing China's standby energy consumption, China Certification Center for Energy Conservation Products (CECP) and the Lawrence Berkeley National Laboratory (LBNL) have, under the sponsorship of the Energy Foundation (EF), entered into a collaboration to develop technical requirements for CECP's labeling program for consumer electronics and office equipment. These technical requirements will be used to qualify products for CECP's energy efficiency endorsement label in China. In the phase I of this collaborative project, CECP and LBNL conducted technical and economic research on televisions and printers in China. Based on the results of this research, CECP developed specifications for, and carried out corresponding energy conservation certifications for these two products. CECP's standby power certification program has made impressive gains in China. Leading manufacturers, such as Haier, Hesons, TCL, Chuangwei, Lenovo, EPSON, Fujitsu, and Brother have participated in CECP's certification activities. Media events organized by CECP have greatly improved the country's awareness of standby power loss. Reducing standby power loss has been formally incorporated into China's energy efficiency policy portfolio and in China's collaboration with the international community on the subject of energy efficiency (IEA, 2001). In phase II of the program, CECP's main task was to assess the market for DVD/VCD (Digital Versatile/Video Disc and Video Compact Disc) players and copiers to analyze the economic and technical benefits of energy conservation potential, and to develop technical specifications for DVD/VCD players and copiers, with technical assistance from LBNL. Having built on the success of Phase I, CECP paid great attention to the appraisal of market conditions and the economic and environmental benefits of reducing standby power loss in DVD/VCD players and copiers, and solicited inputs from stakeholders before finalizing the product certification requirements. This paper summarizes the expected energy conservation and environmental benefits due to the implementation of certification programs for DVD/VCD players and copiers in China.« less

Playing with heart and soul…and genomes: sports implications and applications of personal genomics.

PubMed

Wagner, Jennifer K

2013-01-01

Whether the integration of genetic/omic technologies in sports contexts will facilitate player success, promote player safety, or spur genetic discrimination depends largely upon the game rules established by those currently designing genomic sports medicine programs. The integration has already begun, but there is not yet a playbook for best practices. Thus far discussions have focused largely on whether the integration would occur and how to prevent the integration from occurring, rather than how it could occur in such a way that maximizes benefits, minimizes risks, and avoids the exacerbation of racial disparities. Previous empirical research has identified members of the personal genomics industry offering sports-related DNA tests, and previous legal research has explored the impact of collective bargaining in professional sports as it relates to the employment protections of the Genetic Information Nondiscrimination Act (GINA). Building upon that research and upon participant observations with specific sports-related DNA tests purchased from four direct-to-consumer companies in 2011 and broader personal genomics (PGx) services, this anthropological, legal, and ethical (ALE) discussion highlights fundamental issues that must be addressed by those developing personal genomic sports medicine programs, either independently or through collaborations with commercial providers. For example, the vulnerability of student-athletes creates a number of issues that require careful, deliberate consideration. More broadly, however, this ALE discussion highlights potential sports-related implications (that ultimately might mitigate or, conversely, exacerbate racial disparities among athletes) of whole exome/genome sequencing conducted by biomedical researchers and clinicians for non-sports purposes. For example, the possibility that exome/genome sequencing of individuals who are considered to be non-patients, asymptomatic, normal, etc. will reveal the presence of variants of unknown significance in any one of the genes associated with hypertrophic cardiomyopathy (HCM), long QT syndrome (LQTS), Marfan's syndrome, and other conditions is not inconsequential, and how this information is reported, interpreted, and used may ultimately prevent the individual from participation in competitive sports. Due to the distribution of genetic diversity that reflects our evolutionary and demographic history (including the discernible effects of restricted gene flow and genetic drift associated with cultural constructs of race) and in recognition of previous policies for "leveling" the playing field in competitive sports based on "natural" athletic abilities, preliminary recommendations are provided to discourage genetic segregation of sports and to develop best practice guidelines for genomic sports medicine programs that will facilitate player success, promote player safety, and avoid genetic discrimination within and beyond the program.

Playing with heart and soul…and genomes: sports implications and applications of personal genomics

PubMed Central

2013-01-01

Whether the integration of genetic/omic technologies in sports contexts will facilitate player success, promote player safety, or spur genetic discrimination depends largely upon the game rules established by those currently designing genomic sports medicine programs. The integration has already begun, but there is not yet a playbook for best practices. Thus far discussions have focused largely on whether the integration would occur and how to prevent the integration from occurring, rather than how it could occur in such a way that maximizes benefits, minimizes risks, and avoids the exacerbation of racial disparities. Previous empirical research has identified members of the personal genomics industry offering sports-related DNA tests, and previous legal research has explored the impact of collective bargaining in professional sports as it relates to the employment protections of the Genetic Information Nondiscrimination Act (GINA). Building upon that research and upon participant observations with specific sports-related DNA tests purchased from four direct-to-consumer companies in 2011 and broader personal genomics (PGx) services, this anthropological, legal, and ethical (ALE) discussion highlights fundamental issues that must be addressed by those developing personal genomic sports medicine programs, either independently or through collaborations with commercial providers. For example, the vulnerability of student-athletes creates a number of issues that require careful, deliberate consideration. More broadly, however, this ALE discussion highlights potential sports-related implications (that ultimately might mitigate or, conversely, exacerbate racial disparities among athletes) of whole exome/genome sequencing conducted by biomedical researchers and clinicians for non-sports purposes. For example, the possibility that exome/genome sequencing of individuals who are considered to be non-patients, asymptomatic, normal, etc. will reveal the presence of variants of unknown significance in any one of the genes associated with hypertrophic cardiomyopathy (HCM), long QT syndrome (LQTS), Marfan’s syndrome, and other conditions is not inconsequential, and how this information is reported, interpreted, and used may ultimately prevent the individual from participation in competitive sports. Due to the distribution of genetic diversity that reflects our evolutionary and demographic history (including the discernible effects of restricted gene flow and genetic drift associated with cultural constructs of race) and in recognition of previous policies for “leveling” the playing field in competitive sports based on “natural” athletic abilities, preliminary recommendations are provided to discourage genetic segregation of sports and to develop best practice guidelines for genomic sports medicine programs that will facilitate player success, promote player safety, and avoid genetic discrimination within and beyond the program. PMID:23940833

The effect of deliberate play on tactical performance in basketball.

PubMed

Greco, Pablo; Memmert, Daniel; Morales, Juan C P

2010-06-01

This field-based study analyzed effects of a deliberate-play training program in basketball on tactical game intelligence and tactical creativity. 22 youth basketball players, ages 10 to 12 years, completed basketball training in one of two equal-sized groups. The deliberate-play training program contained unstructured game forms in basketball. The placebo group played in traditional structured basketball game forms. Tactical intelligence and creativity was assessed before and after an 18-lesson intervention. Analysis showed significant training improvement only for the deliberate-play group. In addition, this outperformance of the placebo group was not only observed for tactical creativity but also for tactical intelligence.

Comparison of inflammatory responses to a soccer match between elite male and female players.

PubMed

Souglis, Athanasios G; Papapanagiotou, Angeliki; Bogdanis, Gregory C; Travlos, Antonis K; Apostolidis, Nikolaos G; Geladas, Nikolaos D

2015-05-01

The aim of this study was to compare the inflammatory responses between male and female soccer players for a period of 48 hours after an official match. Blood samples were taken from 83 subjects (22 elite male and 21 elite female soccer players and 20 male and 20 female inactive individuals) in the morning of the game day, immediately after the soccer game and 24 and 48 hours after the match. Average relative exercise intensity during the match was similar in male and female players, as indicated by mean heart rate that was 86.9 ± 4.3 and 85.6 ± 2.3% of maximal heart rate (p = 0.23), respectively. Interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-α) increased 2- to 4-fold above resting values, peaking immediately after the match. C-reactive protein (CRP) and creatine kinase peaked 24 hours after the match. Interleukin 6, CRP, and creatine kinase responses were similar in male and female players, but the peak in TNF-α was 18% higher in male players. Interleukin 6, TNF-α, and CRP at rest were lower in male and female players compared with the control subjects, suggesting a protective effect of regular exercise training regarding the inflammatory profile. The results of this study show that a soccer match induces significant inflammatory responses in both male and female players, with only TNF-α peak values being lower in females. Because of the effects of inflammatory responses on performance and health of the players, it is suggested that coaches and trainers should adjust exercise training programs after a match to promote recovery and protect the athletes' health.

A Prospective Epidemiological Study of Injuries in Japanese National Tournament-Level Badminton Players From Junior High School to University.

PubMed

Miyake, Eiji; Yatsunami, Mitsunobu; Kurabayashi, Jun; Teruya, Koji; Sekine, Yasuhiro; Endo, Tatsuaki; Nishida, Ryuichiro; Takano, Nao; Sato, Seiko; Jae Kyung, Han

2016-03-01

Injury prevention programs have recently been created for various sports. However, a longitudinal study on badminton injuries, as assessed by a team's dedicated medical staff, at the gymnasium has not been performed. We aimed to perform the first such study to measure the injury incidence, severity and type as the first step in creating a badminton injury prevention program. A prospective, longitudinal survey was conducted between April 2012 and March 2013 with 133 national tournament-level badminton players from junior high school to university in Japan with the teams' physical therapists at the gymnasium. Injury incidence was measured as the injury rate (IR) for every 1,000 hour (1000 hour) and IR for every 1,000 athlete exposures (1000 AE). Severity was classified in 5 levels by the number of days the athlete was absent from practice or matches. Injury types were categorized as trauma or overuse. Practice (IR) (1,000 hour) was significantly higher in female players than in male players; the rates increased with increasing age. IR (1,000 AE) was significantly higher in matches than in practice in both sexes of all ages, except for female junior high school students and injuries were most frequent for high school students in matches. The majority of the injuries were slight (83.8%); overuse injuries occurred approximately 3 times more than trauma. This is the first study in which medical staff assessed injuries in badminton, providing value through benchmark data. Injury prevention programs are particularly necessary for female university students in practice and high school students in matches.

Effect of Core Training on Male Handball Players' Throwing Velocity.

PubMed

Manchado, Carmen; García-Ruiz, José; Cortell-Tormo, Juan Manuel; Tortosa-Martínez, Juan

2017-02-01

In handball, throwing velocity is considered to be one of the essential factors in achieving the ultimate aim of scoring a goal. The objective of the present study was to analyze the effect of a core training program on throwing velocity in 30 handball players (age 18.7 ± 3.4 years, body height 179.3 ± 7.0 cm, body mass 78.9 ± 7.7 kg), 16 of whom were in the junior category and 14 of whom were in the senior category. The 30 players were randomly divided into two groups, the control group (n = 15) and the experimental group (n = 15). For a period of ten weeks, both groups attended their regular handball training sessions (four per week), but in addition, the experimental group participated in a program specifically aimed at progressively strengthening the lumbo-pelvic region and consisting of seven exercises performed after the general warm-up in each regular session. Pre- and post-tests were carried out to analyze each player's throwing velocity from different throwing positions and thus assess the effects of this specific training program. Statistically significant differences (p ≤ 0.05) in throwing velocity were observed between the experimental group, which presented a percentage improvement of 4.5%, and the control group, which did not show any improvement. The results seem to indicate that an increase in the strength and stability of the lumbo-pelvic region can contribute to an improvement in the kinetic chain of the specific movement of throwing in handball, thus, increasing throwing velocity.

Changes in body composition of high competition rugby players during the phases of a regular season; influence of diet and exercise load.

PubMed

García, M; Martínez-Moreno, J M; Reyes-Ortiz, A; Suarez Moreno-Arrones, L; García A, A; Garcíacaballero, M

2014-04-01

Top athletes are subjected to intense training to achieve high performance. There are factors such as diet and strenuous exercise that affects body composition and can modify the performance. The aim of the study was to evaluate the effect of a personalized plan of diet and training on body composition. We studied the body composition of 18 professional rugby players using Kinanthropometry parameters. The study was conducted from the preseason to the end of the season taking into account the position of the player for measuring exercise intensity, and developing a personalized nutritional and training plan to each player. At baseline the players were away from the internationally recommended body composition, with high percentages of body fat. Appropriate and personalized diet plans and training custom achieved fat percentages close to those recommended. The personalized program of diet and training directed has adequate leverage to improve all parameters studied them bringing them as close to the ideal. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Personal food systems of male collegiate football players: a grounded theory investigation.

PubMed

Long, Doug; Perry, Christina; Unruh, Scott A; Lewis, Nancy; Stanek-Krogstrand, Kaye

2011-01-01

Factors that affect food choices include the physical and social environments, quality, quantity, perceived healthfulness, and convenience. The personal food choice process was defined as the procedures used by athletes for making food choices, including the weighing and balancing of activities of daily life, physical well-being, convenience, monetary resources, and social relationships. To develop a theoretical model explaining the personal food choice processes of collegiate football players. Qualitative study. National Collegiate Athletic Association Division II football program. Fifteen football players were purposefully sampled to represent various positions, years of athletic eligibility, and ethnic backgrounds. For text data collection, we used predetermined, open-ended questions. Data were analyzed using the constant comparison method. The athletes' words were used to label and describe their interactions and experiences with the food choice process. Member checks and an external audit were conducted by a qualitative methodologist and a nutrition specialist, and the findings were triangulated with the current literature to ensure trustworthiness of the text data. Time was the core category and yielded a cyclic graphic of a theoretical model for the food choice system. Planning hydration, macronutrient strategies, snacks, and healthful food choices emerged as themes. The athletes planned meals and snacks around their academic and athletic schedules while attempting to consume foods identified as healthful. Healthful foods were generally lower in fat but high in preferred macronutrients. High-protein foods were the players' primary goal; carbohydrate consumption was secondary. The athletes had established plans to maintain hydration. Professionals may use these findings to implement educational programs on food choices for football players.

RunJumpCode: An Educational Game for Educating Programming

ERIC Educational Resources Information Center

Hinds, Matthew; Baghaei, Nilufar; Ragon, Pedrito; Lambert, Jonathon; Rajakaruna, Tharindu; Houghton, Travers; Dacey, Simon

2017-01-01

Programming promotes critical thinking, problem solving and analytic skills through creating solutions that can solve everyday problems. However, learning programming can be a daunting experience for a lot of students. "RunJumpCode" is an educational 2D platformer video game, designed and developed in Unity, to teach players the…

University of Miami Hurricane Football Team Off-Season Strength Training Program.

ERIC Educational Resources Information Center

Ganong, Ray

The off-season football strength training and conditioning program at the University of Miami was developed to emphasize commitment and continued intensity of effort on the part of the individual player. The program emphasizes the intrinsic rewards of physical conditioning, positive reinforcement for effort, and individual responsibility for…

Short-Term High Intensity Plyometric Training Program Improves Strength, Power and Agility in Male Soccer Players

PubMed Central

Váczi, Márk; Tollár, József; Meszler, Balázs; Juhász, Ivett; Karsai, István

2013-01-01

The aim of the present study was to investigate the effects of a short-term in-season plyometric training program on power, agility and knee extensor strength. Male soccer players from a third league team were assigned into an experimental and a control group. The experimental group, beside its regular soccer training sessions, performed a periodized plyometric training program for six weeks. The program included two training sessions per week, and maximal intensity unilateral and bilateral plyometric exercises (total of 40 – 100 foot contacts/session) were executed. Controls participated only in the same soccer training routine, and did not perform plyometrics. Depth vertical jump height, agility (Illinois Agility Test, T Agility Test) and maximal voluntary isometric torque in knee extensors using Multicont II dynamometer were evaluated before and after the experiment. In the experimental group small but significant improvements were found in both agility tests, while depth jump height and isometric torque increments were greater. The control group did not improve in any of the measures. Results of the study indicate that plyometric training consisting of high impact unilateral and bilateral exercises induced remarkable improvements in lower extremity power and maximal knee extensor strength, and smaller improvements in soccer-specific agility. Therefore, it is concluded that short-term plyometric training should be incorporated in the in-season preparation of lower level players to improve specific performance in soccer. PMID:23717351

Short-term high intensity plyometric training program improves strength, power and agility in male soccer players.

PubMed

Váczi, Márk; Tollár, József; Meszler, Balázs; Juhász, Ivett; Karsai, István

2013-03-01

The aim of the present study was to investigate the effects of a short-term in-season plyometric training program on power, agility and knee extensor strength. Male soccer players from a third league team were assigned into an experimental and a control group. The experimental group, beside its regular soccer training sessions, performed a periodized plyometric training program for six weeks. The program included two training sessions per week, and maximal intensity unilateral and bilateral plyometric exercises (total of 40 - 100 foot contacts/session) were executed. Controls participated only in the same soccer training routine, and did not perform plyometrics. Depth vertical jump height, agility (Illinois Agility Test, T Agility Test) and maximal voluntary isometric torque in knee extensors using Multicont II dynamometer were evaluated before and after the experiment. In the experimental group small but significant improvements were found in both agility tests, while depth jump height and isometric torque increments were greater. The control group did not improve in any of the measures. Results of the study indicate that plyometric training consisting of high impact unilateral and bilateral exercises induced remarkable improvements in lower extremity power and maximal knee extensor strength, and smaller improvements in soccer-specific agility. Therefore, it is concluded that short-term plyometric training should be incorporated in the in-season preparation of lower level players to improve specific performance in soccer.

Influence of Pokémon Go on physical activity levels of university players: a cross-sectional study.

PubMed

Wong, Fiona Y

2017-02-22

The prevalence of overweight is increasing and the effectiveness of various weight management and exercise programs varied. An augmented reality smartphone game, Pokémon Go, appears to increase activity levels of players. This study assessed the players and ex-players' frequencies and durations of staying outdoors, and walking/jogging before and during the time they played Pokémon Go, evaluated the physical activity levels of players, ex-players and non-players, and investigated the potential factors which determined their play statuses. Students in a university answered an online-questionnaire survey. The IPAQ-short form was incorporated to measure vigorous-intensity activities, moderate-intensity activities and walking. Chi square tests were used to compare frequencies and durations of staying outdoors and walking/jogging, health discomforts and physical activity levels between players, ex-players and non-players. Wilcoxon signed ranks tests were performed to assess the changes prior to and during the time when the players and ex-players played Pokémon Go. Logistic regression analyses were performed to assess factors contributing to playing, quitting or not playing Pokémon Go. 644 university students answered the questionnaire. Compared with the ex-players, the players were significantly more frequent to stay outdoors when playing Pokémon Go (P < 0.001), walk/jog to a location to catch Pokémon, to Pokéstops or Gyms (P < 0.005), as well as walking/jogging to hatch eggs (P < 0.001). Players who never or rarely walked/jogged before spent a mean of 108.19 ± 158.21 min/week to walk/jog in order to play the game which is equivalent to burning 357 kcal/week for a 60-kg person walking a moderate pace. Compared with the non-players, players were more likely to be aged 18-25 years [OR (95% CI) 3.28 (1.28-8.40), P = 0.013], never [OR (95% CI) 10.51 (1.12-98.57), P = 0.039] or rarely [OR (95% CI) 4.00 (1.95-8.23), P < 0.001] stayed outdoors and rarely walked/jogged prior to playing the game [OR (95% CI) 3.88 (1.86-8.05), P < 0.001]. However, there was no significant difference in physical activity levels between the three groups (P = 0.573). Players who used to be sedentary benefited the most from Pokémon Go. The game can be used as a starting point for sedentary people to begin an active lifestyle. The impact of Pokémon Go on physical activity can provide insights to public health workers in using novel strategies in health promotion.

Video Games to Augment Leisure Programming in a State Hospital Residence for Developmentally Disabled Clients.

ERIC Educational Resources Information Center

Powers, Janet; Ball, Thomas S.

1983-01-01

Three mildly and moderately retarded, physically handicapped institutionalized men (17-30 years old) successfully participated in a recreation program involving adapted videogames. Doubles play fostered cooperative social interaction between players. (CL)

COSS Lesson Creation Process

NASA Technical Reports Server (NTRS)

Harper, R. Stephen

1999-01-01

COSS (Crew On-Orbit System Support) is changing. Designed as computer based in-flight refresher training, it is getting good reviews and the demands on the product can be expected to increase. Last year, the lessons were written using Authorware, which had a number of limitations. The most important one was that the navigation and the layout functions were both in one package that was not easy to learn. The lesson creator had to be good at both programming and design. There were also a number of other problems, as detailed in my report last year. This year the COSS unit made the switch to embrace modularity. The navigation function is handled by a player that was custom-written using Delphi. The layout pages are now standard HTML files that can be created using any number of products. This new system gives new flexibility and unties the process from one product (and one company). The player can be re-written by a programmer without affecting the lesson pages. It is also now possible for anybody with a word-processor to make part of the HTML lesson pages and to use many of the new commercially available tools that are being designed for web pages. This summer I created a computer-based training (CBT) lesson on the IBM ThinkPad 760 ED and 760XD laptop computers that should fly on the International Space Station. I also examined the COSS system, the new player and the other new software products.

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

PubMed

Reid, Machar; Morris, Craig

2013-01-01

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

Structure coefficients and strategy selection in multiplayer games.

PubMed

McAvoy, Alex; Hauert, Christoph

2016-01-01

Evolutionary processes based on two-player games such as the Prisoner's Dilemma or Snowdrift Game are abundant in evolutionary game theory. These processes, including those based on games with more than two strategies, have been studied extensively under the assumption that selection is weak. However, games involving more than two players have not received the same level of attention. To address this issue, and to relate two-player games to multiplayer games, we introduce a notion of reducibility for multiplayer games that captures what it means to break down a multiplayer game into a sequence of interactions with fewer players. We discuss the role of reducibility in structured populations, and we give examples of games that are irreducible in any population structure. Since the known conditions for strategy selection, otherwise known as [Formula: see text]-rules, have been established only for two-player games with multiple strategies and for multiplayer games with two strategies, we extend these rules to multiplayer games with many strategies to account for irreducible games that cannot be reduced to those simpler types of games. In particular, we show that the number of structure coefficients required for a symmetric game with [Formula: see text]-player interactions and [Formula: see text] strategies grows in [Formula: see text] like [Formula: see text]. Our results also cover a type of ecologically asymmetric game based on payoff values that are derived not only from the strategies of the players, but also from their spatial positions within the population.

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

Accidental Outcomes Guide Punishment in a “Trembling Hand” Game

PubMed Central

Cushman, Fiery; Dreber, Anna; Wang, Ying; Costa, Jay

2009-01-01

How do people respond to others' accidental behaviors? Reward and punishment for an accident might depend on the actor's intentions, or instead on the unintended outcomes she brings about. Yet, existing paradigms in experimental economics do not include the possibility of accidental monetary allocations. We explore the balance of outcomes and intentions in a two-player economic game where monetary allocations are made with a “trembling hand”: that is, intentions and outcomes are sometimes mismatched. Player 1 allocates $10 between herself and Player 2 by rolling one of three dice. One die has a high probability of a selfish outcome, another has a high probability of a fair outcome, and the third has a high probability of a generous outcome. Based on Player 1's choice of die, Player 2 can infer her intentions. However, any of the three die can yield any of the three possible outcomes. Player 2 is given the opportunity to respond to Player 1's allocation by adding to or subtracting from Player 1's payoff. We find that Player 2's responses are influenced substantially by the accidental outcome of Player 1's roll of the die. Comparison to control conditions suggests that in contexts where the allocation is at least partially under the control of Player 1, Player 2 will punish Player 1 accountable for unintentional negative outcomes. In addition, Player 2's responses are influenced by Player 1's intention. However, Player 2 tends to modulate his responses substantially more for selfish intentions than for generous intentions. This novel economic game provides new insight into the psychological mechanisms underlying social preferences for fairness and retribution. PMID:19707578

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.

Assessing Cognitive Performance in Badminton Players: A Reproducibility and Validity Study.

PubMed

van de Water, Tanja; Huijgen, Barbara; Faber, Irene; Elferink-Gemser, Marije

2017-01-01

Fast reaction and good inhibitory control are associated with elite sports performance. To evaluate the reproducibility and validity of a newly developed Badminton Reaction Inhibition Test (BRIT), fifteen elite (25 ± 4 years) and nine non-elite (24 ± 4 years) Dutch male badminton players participated in the study. The BRIT measured four components: domain-general reaction time, badminton-specific reaction time, domain-general inhibitory control and badminton-specific inhibitory control. Five participants were retested within three weeks on the badminton-specific components. Reproducibility was acceptable for badminton-specific reaction time (ICC = 0.626, CV = 6%) and for badminton-specific inhibitory control (ICC = 0.317, CV = 13%). Good construct validity was shown for badminton-specific reaction time discriminating between elite and non-elite players (F = 6.650, p < 0.05). Elite players did not outscore non-elite players on domain-general reaction time nor on both components of inhibitory control (p > 0.05). Concurrent validity for domain-general reaction time was good, as it was associated with a national ranking for elite (p = 0.70, p < 0.01) and non-elite (p = 0.70, p < 0.05) players. No relationship was found between the national ranking and badminton-specific reaction time, nor both components of inhibitory control (p > 0.05). In conclusion, reproducibility and validity of inhibitory control assessment was not confirmed, however, the BRIT appears a reproducible and valid measure of reaction time in badminton players. Reaction time measured with the BRIT may provide input for training programs aiming to improve badminton players' performance.

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…

A Comparison of Training and Competition Demands in Semiprofessional Male Basketball Players

ERIC Educational Resources Information Center

Fox, Jordan L.; Stanton, Robert; Scanlan, Aaron T.

2018-01-01

Purpose: The purpose of this study was to quantify and compare training and competition demands in basketball. Methods: Fifteen semiprofessional male basketball players wore microsensors during physical conditioning training (PCT), games-based training (GBT), and competition to measure absolute and relative (·min[superscript -1]) PlayerLoad™ (PL)…

Soccer Injuries in Female Youth Players: Comparison of Injury Surveillance by Certified Athletic Trainers and Internet

PubMed Central

Schiff, Melissa A.; Mack, Christopher D.; Polissar, Nayak L.; Levy, Marni R.; Dow, Sara P.; O'Kane, John W.

2010-01-01

Abstract Context: Few authors have evaluated sports injury-surveillance systems that use parental, Internet-based surveys for data collection. Objective: To determine whether certified athletic trainers (ATs) and parental, Internet-based surveys provided comparable data for identifying soccer injuries. Design: Prospective feasibility cohort study. Setting: A soccer association in Seattle, Washington. Patients or Other Participants: Eighty female youth soccer players, ages 12 to 14 years. Main Outcome Measure(s): We compared the data provided by ATs attending 1 soccer practice per week with a weekly soccer-parent, Internet-based system. We measured athlete-exposure hours (AEHs) for each player. We compared injury rates reported by ATs only, Internet-based surveys only, and both systems combined. We evaluated the 2 surveillance systems for agreement on injured body region and laterality of injury using the κ statistic. Results: For ATs only, Internet-based surveys only, and both systems combined, we found acute injury rates of 3.0 per 1000 AEHs, 3.9 per 1000 AEHs, and 4.7 per 1000 AEHs and overuse injury rates of 1.0 per 1000 AEHs, 2.9 per 1000 AEHs, and 2.9 per 1000 AEHs, respectively. Players sustained 27 acute injuries (44% ankle, 11% knee, 11% hip) reported by at least 1 of the 2 systems, with 63% reported by ATs and 85% by Internet-based survey. Players sustained 17 overuse injuries (35% knee, 29% lower leg) reported by either system, with 35% reported by ATs and 100% by Internet-based survey. Among players for whom we had both ATs' and Internet-based survey injury data, body region injured and laterality had very good agreement (κ  =  0.73 to 1.0). Conclusions: The injury rate based on the weekly parental, Internet-based survey was similar to the rate based on the ATs' reporting and had comparable classifications of injured body region and laterality of injury. PMID:20446836

The Effects of Interset Rest on Adaptation to 7 Weeks of Explosive Training in Young Soccer Players

PubMed Central

Ramirez-Campillo, Rodrigo; Andrade, David C.; Álvarez, Cristian; Henríquez-Olguín, Carlos; Martínez, Cristian; Báez-SanMartín, Eduardo; Silva-Urra, Juan; Burgos, Carlos; Izquierdo, Mikel

2014-01-01

The aim of the study was to compare the effects of plyometric training using 30, 60, or 120 s of rest between sets on explosive adaptations in young soccer players. Four groups of athletes (age 10.4 ± 2.3 y; soccer experience 3.3 ± 1.5 y) were randomly formed: control (CG; n = 15), plyometric training with 30 s (G30; n = 13), 60 s (G60; n = 14), and 120 s (G120; n = 12) of rest between training sets. Before and after intervention players were measured in jump ability, 20-m sprint time, change of direction speed (CODS), and kicking performance. The training program was applied during 7 weeks, 2 sessions per week, for a total of 840 jumps. After intervention the G30, G60 and G120 groups showed a significant (p = 0.0001 – 0.04) and small to moderate effect size (ES) improvement in the countermovement jump (ES = 0.49; 0.58; 0.55), 20 cm drop jump reactive strength index (ES = 0.81; 0.89; 0.86), CODS (ES = -1.03; -0.87; -1.04), and kicking performance (ES = 0.39; 0.49; 0.43), with no differences between treatments. The study shows that 30, 60, and 120 s of rest between sets ensure similar significant and small to moderate ES improvement in jump, CODS, and kicking performance during high-intensity short-term explosive training in young male soccer players. Key points Replacing some soccer drills by low volume high-intensity plyometric training would be beneficial in jumping, change of direction speed, and kicking ability in young soccer players. A rest period of 30, 60 or 120 seconds between low-volume high-intensity plyometric sets would induce significant and similar explosive adaptations during a short-term training period in young soccer players. Data from this research can be helpful for soccer trainers in choosing efficient drills and characteristics of between sets recovery programs to enhance performances in young male soccer players. PMID:24790481

Comprehensive Coach Education Reduces Head Impact Exposure in American Youth Football.

PubMed

Kerr, Zachary Y; Yeargin, Susan W; Valovich McLeod, Tamara C; Mensch, James; Hayden, Ross; Dompier, Thomas P

2015-10-01

Despite little evidence that defines a threshold of head impact exposure or that participation in youth sports leads to long-term cognitive impairments, it is prudent to identify methods of reducing the frequency of head impacts. To compare the mean number of head impacts between youth football players in practice and games between leagues that implemented the Heads Up Football (HUF) educational program and those that did not (NHUF). Cohort study; Level of evidence, 2. During the 2014 season, head impact exposure was measured using xPatch accelerometers from 70 youth football players aged 8 to 15 years from 5 leagues. Data were collected during both games and practices. The NHUF group comprised 32 players from 8 teams within 3 leagues. The HUF group comprised 38 players from 7 teams within 2 leagues. Independent-sample t tests evaluated differences in head impact exposure across groups (ie, HUF and NHUF). Players (mean ± SD: age, 11.7 ± 1.4 years; height, 152.2 ± 10.5 cm; weight, 51.6 ± 9.6 kg) experienced a total of 7478 impacts over 10g, of which 4250 (56.8%) and 3228 (43.2%) occurred in practices and games, respectively. The majority of impacts occurred within the NHUF group (62.0%), followed by the HUF group (38.0%). With a 10g impact threshold, the mean number of impacts during practice per individual event was lower in the HUF group (mean ± SD, 5.6 ± 2.9) than in the NHUF group (mean ± SD, 8.9 ± 3.1; difference, 3.4; 95% CI, 2.9-3.9). This difference was attenuated when the threshold was changed to 20g but remained significant (difference, 1.0; 95% CI, 0.7-1.3). At both the 10g and 20g impact thresholds, no differences were found in games. Players who participated in HUF leagues accumulated fewer head impacts per practice at both the 10g and 20g thresholds. Youth football leagues should consider the HUF educational program, while exploring additional interventions, to help reduce the number of head impacts in players.

Comprehensive Coach Education Reduces Head Impact Exposure in American Youth Football

PubMed Central

Kerr, Zachary Y.; Yeargin, Susan W.; Valovich McLeod, Tamara C.; Mensch, James; Hayden, Ross; Dompier, Thomas P.

2015-01-01

Background: Despite little evidence that defines a threshold of head impact exposure or that participation in youth sports leads to long-term cognitive impairments, it is prudent to identify methods of reducing the frequency of head impacts. Purpose: To compare the mean number of head impacts between youth football players in practice and games between leagues that implemented the Heads Up Football (HUF) educational program and those that did not (NHUF). Study Design: Cohort study; Level of evidence, 2. Methods: During the 2014 season, head impact exposure was measured using xPatch accelerometers from 70 youth football players aged 8 to 15 years from 5 leagues. Data were collected during both games and practices. The NHUF group comprised 32 players from 8 teams within 3 leagues. The HUF group comprised 38 players from 7 teams within 2 leagues. Independent-sample t tests evaluated differences in head impact exposure across groups (ie, HUF and NHUF). Results: Players (mean ± SD: age, 11.7 ± 1.4 years; height, 152.2 ± 10.5 cm; weight, 51.6 ± 9.6 kg) experienced a total of 7478 impacts over 10g, of which 4250 (56.8%) and 3228 (43.2%) occurred in practices and games, respectively. The majority of impacts occurred within the NHUF group (62.0%), followed by the HUF group (38.0%). With a 10g impact threshold, the mean number of impacts during practice per individual event was lower in the HUF group (mean ± SD, 5.6 ± 2.9) than in the NHUF group (mean ± SD, 8.9 ± 3.1; difference, 3.4; 95% CI, 2.9-3.9). This difference was attenuated when the threshold was changed to 20g but remained significant (difference, 1.0; 95% CI, 0.7-1.3). At both the 10g and 20g impact thresholds, no differences were found in games. Conclusion: Players who participated in HUF leagues accumulated fewer head impacts per practice at both the 10g and 20g thresholds. Youth football leagues should consider the HUF educational program, while exploring additional interventions, to help reduce the number of head impacts in players. PMID:26779546

Injury risk is low among world-class volleyball players: 4-year data from the FIVB Injury Surveillance System.

PubMed

Bere, Tone; Kruczynski, Jacek; Veintimilla, Nadège; Hamu, Yuichiro; Bahr, Roald

2015-09-01

Little is known about the rate and pattern of injuries in international volleyball competition. To describe the risk and pattern of injuries among world-class players based on data from the The International Volleyball Federation (FIVB) Injury Surveillance System (ISS) (junior and senior, male and female). The FIVB ISS is based on prospective registration of injuries by team medical staff during all major FIVB tournaments (World Championships, World Cup, World Grand Prix, World League, Olympic Games). This paper is based on 4-year data (September 2010 to November 2014) obtained through the FIVB ISS during 32 major FIVB events (23 senior and 9 junior). The incidence of time-loss injuries during match play was 3.8/1000 player hours (95% CI 3.0 to 4.5); this was greater for senior players than for junior players (relative risk: 2.04, 1.29 to 3.21), while there was no difference between males and females (1.04, 0.70 to 1.55). Across all age and sex groups, the ankle was the most commonly injured body part (25.9%), followed by the knee (15.2%), fingers/thumb (10.7%) and lower back (8.9%). Injury incidence was greater for centre players and lower for liberos than for other player functions; injury patterns also differed between player functions. Volleyball is a very safe sport, even at the highest levels of play. Preventive measures should focus on acute ankle and finger sprains, and overuse injuries in the knee, lower back and shoulder. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

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.

Exposing an “Intangible” Cognitive Skill among Collegiate Football Players: Enhanced Interference Control

PubMed Central

Wylie, Scott A.; Bashore, Theodore R.; Van Wouwe, Nelleke C.; Mason, Emily J.; John, Kevin D.; Neimat, Joseph S.; Ally, Brandon A.

2018-01-01

American football is played in a chaotic visual environment filled with relevant and distracting information. We investigated the hypothesis that collegiate football players show exceptional skill at shielding their response execution from the interfering effects of distraction (interference control). The performances of 280 football players from National Collegiate Athletic Association Division I football programs were compared to age-matched controls in a variant of the Eriksen flanker task (Eriksen and Eriksen, 1974). This task quantifies the magnitude of interference produced by visual distraction on split-second response execution. Overall, football athletes and age controls showed similar mean reaction times (RTs) and accuracy rates. However, football athletes were more proficient at shielding their response execution speed from the interfering effects of distraction (i.e., smaller flanker effect costs on RT). Offensive and defensive players showed smaller interference costs compared to controls, but defensive players showed the smallest costs. All defensive positions and one offensive position showed statistically smaller interference effects when compared directly to age controls. These data reveal a clear cognitive advantage among football athletes at executing motor responses in the face of distraction, the existence and magnitude of which vary by position. Individual differences in cognitive control may have important implications for both player selection and development to improve interference control capabilities during play. PMID:29479325

Somatotype, Level of Competition, and Performance in Attack in Elite Male Volleyball

PubMed Central

Giannopoulos, Nikiforos; Vagenas, George; Noutsos, Konstantinos; Barzouka, Karolina; Bergeles, Nikolaos

2017-01-01

Abstract This study investigated the relationship between somatotype, level of competition, and performance in attack in elite level male volleyball players. The objective was to test for the potential covariation of competition level (Division A1 vs. A2) and playing position (hitters vs. centers vs. opposites) considering performance in attack. Anthropometric, body composition and somatotype variables were measured according to the Heath-Carter method. The attack actions of 144 players from 48 volleyball matches were analyzed and their performance was rated using a 5-point numerical scale. Results showed that players of Division A1 were taller, heavier, more muscular, and less endomorphic compared to those of Division A2. MANOVA and follow-up discriminant function analysis revealed somatotype differences among playing positions with centers and opposites being endomorph-ectomorph and hitters being central. Centers performed constantly better than hitters and opposites regardless of the division and somatotype. Multiple linear regression analysis showed that variables defining ectomorph and endomorph players, centers, and players of Division A1 significantly determined the relative performance superiority and were able to explain the variation in performance by almost 25%. These results could be taken into account by coaches when assigning players to particular playing positions or when designing individualized position-specific training programs. PMID:28828084

Somatotype, Level of Competition, and Performance in Attack in Elite Male Volleyball.

PubMed

Giannopoulos, Nikiforos; Vagenas, George; Noutsos, Konstantinos; Barzouka, Karolina; Bergeles, Nikolaos

2017-09-01

This study investigated the relationship between somatotype, level of competition, and performance in attack in elite level male volleyball players. The objective was to test for the potential covariation of competition level (Division A1 vs. A2) and playing position (hitters vs. centers vs. opposites) considering performance in attack. Anthropometric, body composition and somatotype variables were measured according to the Heath-Carter method. The attack actions of 144 players from 48 volleyball matches were analyzed and their performance was rated using a 5-point numerical scale. Results showed that players of Division A1 were taller, heavier, more muscular, and less endomorphic compared to those of Division A2. MANOVA and follow-up discriminant function analysis revealed somatotype differences among playing positions with centers and opposites being endomorph-ectomorph and hitters being central. Centers performed constantly better than hitters and opposites regardless of the division and somatotype. Multiple linear regression analysis showed that variables defining ectomorph and endomorph players, centers, and players of Division A1 significantly determined the relative performance superiority and were able to explain the variation in performance by almost 25%. These results could be taken into account by coaches when assigning players to particular playing positions or when designing individualized position-specific training programs.

Brachial neuropraxia in Canadian Atlantic University sport football players: what is the incidence of "stingers"?

PubMed

Charbonneau, Rebecca M E; McVeigh, Sonja A; Thompson, Kara

2012-11-01

The objectives of this study were (1) to determine the incidence of brachial neuropraxia (stingers) among varsity football players during the 2010 season; (2) to determine if associations exist between sustaining a stinger and previous history of stingers, years played, equipment, age, body mass index (BMI), and conditioning; and (3) to provide descriptive statistics regarding stingers and position played, symptoms, activity during injury, mechanism of tackling, and reporting of stingers. Retrospective. Canadian Atlantic University Sport football league. Two hundred forty-four players. Two written questionnaires. Number of players experiencing stingers that occurred during the 2010 season. The incidence was 26% (64 of 244). A multivariate analysis revealed that previous history of a stinger (P < 0.0001) and years played (P = 0.0018) were associated with sustaining a stinger. There was no statistically significant effect related to additional equipment, a player's age, BMI, or participation in a strength training program. Linebackers, offensive linemen, and wide receivers had the highest incidence of stingers. The most frequent symptoms reported were tingling, numbness, burning, and weakness. Of all stingers sustained, only 59% (38 of 64) were reported to medical staff. Stingers are a common injury in Canadian university football and are underreported to medical staff. Education of players at increased risk is needed.

Specific physiological and biomechanical performance in elite, sub-elite and in non-elite male team handball players.

PubMed

Wagner, Herbert; Fuchs, Philip X; von Duvillard, Serge P

2018-01-01

Team handball is a dynamic sport game that is played professionally in numerous countries. However, knowledge about training and competition is based mostly on practical experience due to limited scientific studies. Consequently, the aims of our study were to compare specific physiological and biomechanical performance in elite, sub-elite and in non-elite male team handball players. Thirty-six elite, sub-elite and non-elite male team handball players performed a game based performance test, upper-body and lower-body strength tests, 30-m sprint test, counter movement jump test and an incremental treadmill running test. Significant differences (P<0.05) were found for the peak oxygen uptake, heart rate, offense and defense time, jump height and ball velocity during the jump throw in the game based performance test, maximal oxygen uptake in the incremental treadmill running test as well as in maximal leg strength and leg explosive strength in the isometric strength test. Elite male players have an enhanced specific agility, a better throwing performance, a higher team handball specific oxygen uptake and higher leg strength compared to sub-elite and non-elite players. Based on these results we recommend that training in team handball should focus on game based training methods to improve performance in specific agility, endurance and technique.

Hamstring-and-Lower-Back Flexibility in Male Amateur Soccer Players.

PubMed

van der Horst, Nick; Priesterbach, Annique; Backx, Frank; Smits, Dirk-Wouter

2017-01-01

This study investigated the hamstring-and-lower-back flexibility (HLBF) of male adult amateur soccer players, using the sit-and-reach test (SRT), with a view to obtaining population-based reference values and to determining whether SRT scores are associated with player characteristics. Cross-sectional cohort study. Teams from high-level Dutch amateur soccer competitions were recruited for participation. Dutch male high-level amateur field soccer players (n = 449) of age 18 to 40 years. Players with a hamstring injury at the moment of SRT-measurement or any other injury that prevented them from following the SRT protocol were excluded. Sit-and-reach test scores were measured and then population-based reference values were calculated as follows: >2SD below mean (defining "very low" HLBF), 1SD-2SD below mean ("low" HLBF), 1SD below mean to 1SD above mean ("normal" HLBF), 1SD-2SD above mean ("high" HLBF), and >2SD above mean ("very high" HLBF). Whether SRT scores were correlated with player characteristics was determined using a Pearson correlation coefficient or Spearman rho. Sit-and-reach test scores ranged from 0 to 43.5 cm (mean 22.0 cm, SD 9.2). The cutoff points for population-based reference values were <3.5 cm for "very low", 3.5 to 13.0 cm for "low", 13.0 to 31.0 cm for "normal", 31.0 to 40.5 cm for "high", and >40.5 cm for "very high". Sit-and-reach test scores were significantly associated with players' height (ρ = -0.132, P = 0.005), body mass index (r = 0.114, P = 0.016), and history of anterior cruciate ligament surgery (P < 0.001). This study is the first to describe the HLBF of amateur soccer players. The SRT reference values with cutoff points may facilitate evidence-based decision making regarding HLBF, and the SRT might be a useful tool to assess injury risk, performance, or for diagnostic purposes.

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.

Muscle injuries of the lower extremity: a comparison between young and old male elite soccer players.

PubMed

Svensson, Kjell; Alricsson, Marie; Karnebäck, Gustav; Magounakis, Theo; Werner, Suzanne

2016-07-01

The aim of this study was to make a comparison between players in two age groups in an elite male soccer team regarding injury localisation within the muscle-tendon unit, injury size and muscle group in terms of muscle injuries of the lower extremity. Cohort study based on data collected from a Swedish elite male soccer team during the seasons 2007-2012. In total, 145 muscle injuries were included. Injury localisation to the tendon or muscle, the size of haematoma and the affected muscle group were assessed using ultrasound. Age comparison was made between younger players (≤23 years) and older players (>23 years). No difference regarding injury localisation to either the tendon or the muscle, or the size of haematoma between the two age groups was found. However, the older group of players suffered a significantly higher number of injuries to the triceps surae than the younger players (p = 0.012). In a Swedish team of male soccer players at elite level, there was no difference between players 23 years or younger and players older than 23 years, in terms of injury distribution to muscles or tendons. Players older than 23 years sustained more injuries to triceps surae when compared with players 23 years or younger. The clinical relevance is to pay attention to muscle function of triceps surae in older players and to screen those players who may need an injury prevention programme. II.

Performance and anthropometric characteristics of prospective elite junior Australian footballers: a case study in one junior team.

PubMed

Veale, James P; Pearce, Alan J; Koehn, Stefan; Carlson, John S

2008-04-01

The aim of the study was to compare anthropometric and physical performance data of players who were selected for a Victorian elite junior U18 Australian rules football squad. Prior to the selection of the final training squad, 54 players were assessed using a battery of standard anthropometric and physical performance tests. Multivariate analysis (MANOVA) showed significant (p<0.05) differences between selected and non-selected players when height, mass, 20-m sprint, agility and vertical jump height were considered collectively. Univariate analysis revealed that the vertical jump was the only significant (p<0.05) individual test and a near significant trend (p=0.07) for height differentiating between selected and non-selected players with medium effect sizes for all other tests except endurance. In this elite junior football squad, physical characteristics can be observed that discriminate between players selected and non-selected, and demonstrates the value of physical fitness testing within the talent identification process of junior (16-18 years) players for squad and/or team selection. Based on MANOVA results, the findings from this study suggest team selection appeared to be related to a generally higher performance across the range of tests. Further, age was not a confounding variable as players selected tended to be younger than those non-selected. These findings reflect the general consensus that, in state-based junior competition, there is evidence of promoting overall player development, selecting those who are generally able to fulfil a range of positions and selecting players on their potential.

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

National Collegiate Athletic Association Division I Football Players' Perceptions of Women in the Athletic Training Room Using a Role Congruity Framework

PubMed Central

O'Connor, Caitlin; Grappendorf, Heidi; Burton, Laura; Harmon, Sandra M.; Henderson, Angela C.; Peel, Judy

2010-01-01

Abstract Context: Previous researchers have demonstrated that male and female athletes feel more comfortable with treatment by a same-sex athletic trainer for sex-specific injuries and conditions. Objective: To address football players' comfort with care provided by same-sex and opposite-sex athletic trainers for sex-specific and non–sex-specific injuries and conditions through the lens of role congruity theory. Design: Cross-sectional study for the quantitative data and qualitative study for the qualitative data. Setting: Two National Collegiate Athletic Association Division I Football Bowl Series university football programs. Patients or Other Participants: Male football players within the 2 university programs. Data Collection and Analysis: We replicated existing methods and an existing survey to address male football players' comfort levels. Additionally, an open-ended question was used to determine male football players' perceptions of female athletic trainers. Paired-samples t tests were conducted to identify differences between the responses for the care given by a male athletic trainer and for the care given by a female athletic trainer. Three categories were analyzed: general medical conditions, psychological conditions, and sex-specific injuries. The qualitative data were coded and analyzed using content analysis. Results: Male football players were more comfortable with treatment by a male athletic trainer (mean  =  3.61 ± 1.16) for sex-specific injuries and conditions than they were with treatment by a female athletic trainer (mean  =  2.82 ± 1.27; P < .001). No significant results were found for comfort with overall psychological conditions, although a female athletic trainer was preferred over a male athletic trainer for the treatment of depression (mean  =  3.71 ± 1.07 versus mean  =  3.39 ± 1.16, respectively; P < .001). Qualitative data provided support for role congruity theory. Conclusions: Both quantitative and qualitative evidence were provided for the support of role congruity theory. PMID:20617914

What is the Value of a National Football League Draft Pick? An Analysis Based on Changes Made in the Collective Bargaining Agreement.

PubMed

Kraeutler, Matthew J; Carver, Trevor J; Belk, John W; McCarty, Eric C

2018-06-01

Kraeutler, MJ, Carver, TJ, Belk, JW, and McCarty, EC. What is the value of a National Football League draft pick? An analysis based on changes made in the collective bargaining agreement. J Strength Cond Res 32(6): 1656-1661, 2018-The purpose of this study was to analyze and compare the value of players drafted in early rounds of the National Football League (NFL) Draft since the new collective bargaining agreement began in 2011. The NFL's player statistics database and database of player contract details were searched for players drafted in the first 3 rounds of the 2011 to 2013 NFL Drafts. Performance outcomes specific to each position were divided by each player's salary to calculate a value statistic. Various demographics, NFL Combine results, and total number of games missed because of injury were also recorded for each player. These statistics were compared within each position between players selected in the first round of the NFL Draft (group A) vs. those drafted in the second or third round (group B). A total of 147 players were included (group A 35, group B 112). Overall, players in group A were significantly taller (p ≤ 0.01) and heavier (p = 0.037) than players in group B. Group B demonstrated significantly greater value statistics than group A for quarterbacks (p = 0.028), wide receivers (p ≤ 0.001), defensive tackles (p = 0.019), and cornerbacks (p ≤ 0.001). No significant differences were found between groups with regard to number of games missed because of injury. Players drafted in the second or third rounds of the NFL Draft often carry more value than those drafted in the first round. NFL teams may wish to more frequently trade down in the Draft rather than trading up.

Effects of an In-season Plyometric Training Program on Repeated Change of Direction and Sprint Performance in the Junior Soccer Player.

PubMed

Hammami, Mehréz; Negra, Yassine; Aouadi, Ridha; Shephard, Roy J; Chelly, Mohamed Souhaiel

2016-12-01

Hammami, M, Negra, Y, Aouadi, R, Shephard, RJ, and Chelly, MS. Effects of an in-season plyometric training program on repeated change of direction and sprint performance in the junior soccer player. J Strength Cond Res 30(12): 3312-3320, 2016-We aimed to determine the gains in explosive movements of male junior soccer players induced by incorporating an 8-week plyometric training program (PTP) into a standard soccer conditioning regimen 5 months after the beginning of the competitive season. Our hypothesis was that PTP would enhance explosive movements, and thus sprint running, repeated shuttle sprint ability (RSSA), agility and the ability to make repeated changes of direction (RCOD). A group of junior soccer players were randomly divided into 2 groups: an experimental group (E, n = 15, age 15.7 ± 0.2 years) and a control group (C, n = 13, age 15.8 ± 0.2 years). The participants in E and C performed training exercises and matches together, but for an 8-week period in the latter part of the season, the experimental group replaced a part of the normal regimen (the tactical session) by a biweekly course of PTP (hurdle and drop jumps). Two familiarization sessions were held 2 weeks before definitive testing. The ability of the players was assessed by 3 agility tests (a sprint test with 180° turns, a 9-3-6-3-9 m sprint with backward and forward running, and a four 5-m sprint test with turns); 2 repeated sprint tests (RSSA and RCOD); and running times over 5-, 10-, 20-, 30-, and 40-m distances. Participants in E showed gains relative to C in sprint times (p ≤ 0.05 for 5, 10, and 20 m), and 2 of 3 the RCOD parameters (RCOD best, p ≤ 0.001; RCOD total, p ≤ 0.05). However, with the pattern of plyometric training that we adopted, and perhaps because participants were in good initial physical condition, the agility and RSSA test scores remained unchanged. Nevertheless, we conclude that our PTP can be commended to junior soccer players as a means of improving important components of their physical performance.

The effects of resistance training interventions on vertical jump performance in basketball players: a meta-analysis.

PubMed

Sperlich, Paula F; Behringer, Michael; Mester, Joachim

2016-01-01

Vertical jump performance is one of the key factors in basketball. In order to determine the effectiveness of previously published interventions and their influencing factors we performed a meta-analysis. A computerized search was conducted using the databases PubMed (1966), Web of Science (1900), SPORTDiscus™ (1975),Medline (1966) and SportPilot (2008). Studies involving healthy male or female basketball players at any age and performance level were included. All trials had to investigate the benefits of resistance training programs on jumping performance in basketball players and provide a control group. The effect size (ES) was computed and the relationship between ESs and continuous variables was examined by meta-regressions, whereas subgroup meta-analyses and z-tests were used to assess the impact of categorical moderator variables. The meta-analysis included 14 studies with 20 subgroups and a total of 37 outcomes. A total of 399 participants were examined, N.=157 served as control and N.=242 took part in particular training interventions. The overall weighted ES of 0.78 (95% CI 0.41, 1.15) was significantly greater than zero (P<0.001). None of the categorical moderator variables affected the training effect. However, positive correlations were found for training duration (r=0.68; P=0.02). The present meta-analysis demonstrates that resistance training throughout the year, using bodyweight or external weight, significantly improves vertical jump performance in healthy basketball players. Since vertical jump improvements were independent of intervention period but dependent on the duration of each individual training session the total training amount should be based on longer training sessions.

Changes in Body Composition and Strength of Female Athletes on Two Different Training Programs.

ERIC Educational Resources Information Center

Oyster, Nancy

Thirty-one championship caliber women athletes participating on varsity teams at Ohio State University were trained using two different conditioning programs, in an attempt to determine the physiological outcomes of weight training versus cardiovascular-oriented conditioning. Fourteen tennis players followed a program of high-resistance weight…

Player-Driven Video Analysis to Enhance Reflective Soccer Practice in Talent Development

ERIC Educational Resources Information Center

Hjort, Anders; Henriksen, Kristoffer; Elbæk, Lars

2018-01-01

In the present article, we investigate the introduction of a cloud-based video analysis platform called Player Universe (PU). Video analysis is not a new performance-enhancing element in sports, but PU is innovative in how it facilitates reflective learning. Video analysis is executed in the PU platform by involving the players in the analysis…

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 motion, which could control mechanical loading patterns on the low back and minimize pain symptoms in players with chronic LBP.

High-intensity interval training has positive effects on performance in ice hockey players.

PubMed

Naimo, M A; de Souza, E O; Wilson, J M; Carpenter, A L; Gilchrist, P; Lowery, R P; Averbuch, B; White, T M; Joy, J

2015-01-01

In spite of the well-known benefits that have been shown, few studies have looked at the practical applications of high-intensity interval training (HIIT) on athletic performance. This study investigated the effects of a HIIT program compared to traditional continuous endurance exercise training. 24 hockey players were randomly assigned to either a continuous or high-intensity interval group during a 4-week training program. The interval group (IG) was involved in a periodized HIIT program. The continuous group (CG) performed moderate intensity cycling for 45-60 min at an intensity that was 65% of their calculated heart rate reserve. Body composition, muscle thickness, anaerobic power, and on-ice measures were assessed pre- and post-training. Muscle thickness was significantly greater in IG (p=0.01) when compared to CG. The IG had greater values for both ∆ peak power (p<0.003) and ∆ mean power (p<0.02). Additionally, IG demonstrated a faster ∆ sprint (p<0.02) and a trend (p=0.08) for faster ∆ endurance test time to completion for IG. These results indicate that hockey players may utilize short-term HIIT to elicit positive effects in muscle thickness, power and on-ice performance. © Georg Thieme Verlag KG Stuttgart · New York.

Player Load in Elite Netball: Match, Training, and Positional Comparisons.

PubMed

Young, Christopher M; Gastin, Paul B; Sanders, Nick; Mackey, Luke; Dwyer, Dan B

2016-11-01

The activity profile of competition and training in elite netball has not been comprehensively reported in the literature. To measure and analyze player load in elite netballers during matches and training sessions. The primary research question was, How does player load vary between playing positions in a match and between matches and training sessions? Various measures of player load were recorded in 12 elite professional netballers with a mean ± SD age of 26 ± 4.9 y and height of 183.2 ± 8.7 cm. Player load was assessed using a published method that uses accelerometry. Load was represented as total load in arbitrary units (au), playing intensity (au/min), and relative time spent in each of 4 playing intensity zones (low, low to moderate, moderate, and high). Data from 15 games and up to 17 training sessions were analyzed for each player. Player load in matches for the goal-based positions (goal shooter, goal keeper, and goal defense) tended to be lower than the attacking and wing-based positions (goal attack, wing attack, wing defense, and center). The difference was largely due to the amount of time spent in low-intensity activity. Playing intensity of matches was greater than in training sessions; however, the total time spent in moderate- to high-intensity activities was not practically different. Accelerometry is a valuable method of measuring player load in netball, and the present results provide new information about the activity profile of different playing positions.

Evaluation of a real world intervention using professional football players to promote a healthy diet and physical activity in children and adolescents from a lower socio-economic background: a controlled pretest-posttest design.

PubMed

Dubuy, Veerle; De Cocker, Katrien; De Bourdeaudhuij, Ilse; Maes, Lea; Seghers, Jan; Lefevre, Johan; De Martelaer, Kristine; Brooke, Hannah; Cardon, Greet

2014-05-16

The increasing rates of obesity among children and adolescents, especially in those from lower socio-economic backgrounds, emphasise the need for interventions promoting a healthy diet and physical activity. The present study aimed to examine the effectiveness of the 'Health Scores!' program, which combined professional football player role models with a school-based program to promote a healthy diet and physical activity to socially vulnerable children and adolescents. The intervention was implemented in two settings: professional football clubs and schools. Socially vulnerable children and adolescents (n = 165 intervention group, n = 440 control group, aged 10-14 year) provided self-reported data on dietary habits and physical activity before and after the four-month intervention. Intervention effects were evaluated using repeated measures analysis of variance. In addition, a process evaluation was conducted. No intervention effects were found for several dietary behaviours, including consumption of breakfast, fruit, soft drinks or sweet and savoury snacks. Positive intervention effects were found for self-efficacy for having a daily breakfast (p < 0.01), positive attitude towards vegetables consumption (p < 0.01) and towards lower soft drink consumption (p < 0.001). A trend towards significance (p < 0.10) was found for self-efficacy for reaching the physical activity guidelines. For sports participation no significant intervention effect was found. In total, 92 pupils completed the process evaluation, the feedback was largely positive. The 'Health Scores!' intervention was successful in increasing psychosocial correlates of a healthy diet and PA. The use of professional football players as a credible source for health promotion was appealing to socially vulnerable children and adolescents.

The Effects of Sport-Specific Drills Training or High-Intensity Interval Training in Young Tennis Players.

PubMed

Fernandez-Fernandez, Jaime; Sanz, David; Sarabia, Jose Manuel; Moya, Manuel

2017-01-01

To compare the effects of combining high-intensity training (HIT) and sport-specific drill training (MT) versus sportspecific drill training alone (DT) on fitness performance characteristics in young tennis players. Twenty young tennis players (14.8 ± 0.1 y) were assigned to either DT (n = 10) or MT (n = 10) for 8 wk. Tennis drills consisted of two 16- to 22-min on-court exercise sessions separated by 3 min of passive rest, while MT consisted of 1 sport-specific DT session and 1 HIT session, using 16-22 min of runs at intensities (90-95%) related to the velocity obtained in the 30-15 Intermittent Fitness Test (V IFT ) separated by 3 min of passive rest. Pre- and posttests included peak oxygen uptake (VO 2 peak), V IFT , speed (20 m, with 5- and 10-m splits), 505 Agility Test, and countermovement jump (CMJ). There were significant improvements after the training period in VO 2 peak (DT 2.4%, ES = moderate; MT 4.2%, ES = large) and V IFT (DT 2.2%, ES = small; MT 6.3%, ES = large) for both DT and MT, with no differences between training protocols. Results also showed a large increase in the 505 Agility Test after MT, while no changes were reported in the other tests (sprint and CMJ), either for MT or DT. Even though both training programs resulted in significant improvements in aerobic performance, a mixed program combining tennis drills and runs based on the V IFT led to greater gains and should be considered the preferred training method for improving aerobic power in young athletes.

Checkmate: Capturing Gifted Students' Logical Thinking Using Chess.

ERIC Educational Resources Information Center

Rifner, Philip J.; Feldhusen, John F.

1997-01-01

Describes the use of chess instruction to develop abstract thinking skills and problem solving among gifted students. Offers suggestions for starting school chess programs, teaching and evaluating chess skills, and measuring the success of both student-players and the program in general. (PB)

Doing well by doing good. The 7 benefits of a meaningful corporate social responsibility program.

PubMed

Macdonald, Deborah

2008-08-01

You want your medical group to be a good community player--but you need to attract new patients, retain top staff and manage your bottom line. A corporate social responsibility program may be the shrewd solution.

U.S. advanced launch vehicle technology programs : Quarterly Launch Report : special report

DOT National Transportation Integrated Search

1996-01-01

U.S. firms and U.S. government agencies are jointly investing in advanced launch vehicle technology. This Special Report summarizes U.S. launch vehicle technology programs and highlights the changing : roles of government and industry players in pick...

Prevalence of Inadequate Immunity to Measles, Mumps, Rubella, and Varicella in MLB and NBA Athletes.

PubMed

Conway, Justin J; Toresdahl, Brett G; Ling, Daphne I; Boniquit, Nicole T; Callahan, Lisa R; Kinderknecht, James J

2018-05-01

Multiple outbreaks of vaccine-preventable viral diseases have occurred in professional sports in recent years. Currently, there is no established protocol for vaccination or immunity screening for professional athletes. There are significant differences in the prevalence of inadequate immunity dependent on age, sport, country of birth, and participation in collegiate sports. Cross-sectional cohort study. Level 4. A sample of Major League Baseball (MLB) and National Basketball Association (NBA) players were screened for serologic evidence of immunity to measles, mumps, rubella, and varicella prior to the 2015 and 2016 seasons. The results were designated as adequate (immune) or inadequate (equivocal or nonimmune) based on laboratory criteria. Comparison with an age-matched control group was performed using data from the National Health and Nutrition Examination Survey (NHANES). A total of 98 athletes (62 MLB, 36 NBA) were screened. The prevalence of inadequate immunity for any virus was 35.5% in MLB players and 33.3% in NBA players. There was a significantly greater risk of inadequate immunity to rubella (risk ratio, 6.38; P < 0.01) and varicella (risk ratio, 4.21; P < 0.01) in athletes compared with the age-matched NHANES population. Our analysis did not reveal differences in rates of immunity based on sport, country of birth (US born vs international), or participation in college athletics. There was a lower rate of inadequate immunity to varicella with increasing age (odds ratio, 0.72; P = 0.05). One-third of athletes studied had inadequate immunity to 1 of the 4 viruses tested. Younger players had a significantly greater risk of inadequate immunity to varicella. Birth outside the US and lack of participation in college athletics were not found to influence immunity rates. These results can inform the development of future screening programs to prevent outbreaks of viral infections in professional athletes.

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.

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.

Effects of dry-land vs. in-water specific strength training on professional male water polo players' performance.

PubMed

de Villarreal, Eduardo Sáez; Suarez-Arrones, Luis; Requena, Bernardo; Haff, G Gregory; Ramos-Veliz, Rafael

2014-11-01

We compared the effects of 6-week dry-land and in-water specific strength training combined with a water polo (WP) program on 7 sport-specific performance parameters. Nineteen professional players were randomly assigned to 2 groups: in-water strength group (WSG) (in-water training only) and dry-land strength group (LSG). The program included 3 weekly strength training sessions and 5 days of WP training per week for 6 weeks during the preseason. Ten-meter T-agility test, 20-m maximal sprint swim, maximal dynamic strength (1 repetition maximum), bench press (BP) and full squat (FS), in-water boost, countermovement jump (CMJ), and WP throwing speed were measured. Significant improvements (p ≤ 0.05) were found in the experimental groups in some variables: CMJ in the LSG and WSG (2.35 cm, 9.07%, effect size [ES] = 0.89; and 2.6 cm, 7.6%, ES = 0.83, respectively), in-water boost increased in the WSG group (4.1 cm; 11.48%; ES = 0.70), and FS and BP increased (p ≤ 0.05) only in the LSG group (12.1 kg; 11.27%; ES = 1.15 and 8.3 kg; 9.55%; ES = 1.30, respectively). There was a decrease of performance in agility test (-0.55 seconds; 5.60%; ES = 0.74). Both dry-land and in-water specific strength training and high-intensity training in these male WP players produced medial to large effects on most WP-specific performance parameters. Therefore, we propose modifications to current training methodology for WP players in preseason to include both the training programs (dry-land and in-water specific strength training and high-intensity training) for athlete preparation in this sport.

Can motor control training lower the risk of injury for professional football players?

PubMed

Hides, Julie A; Stanton, Warren R

2014-04-01

Among injuries reported by the Australian Football League (AFL), lower limb injuries have shown the highest incidence and prevalence rates. Deficits in the muscles of the lumbopelvic region, such as a smaller size of multifidus (MF) muscle, have been related to the occurrence of lower limb injuries in the preseason in AFL players. Motor control training programs have been effective in restoring the size and control of the MF muscle, but the relationship between motor control training and occurrence of injuries has not been extensively examined. This pre- and postintervention trial was delivered during the playing season as a panel design with three groups. The motor control program involved voluntary contractions of the MF, transversus abdominis, and pelvic floor muscles while receiving feedback from ultrasound imaging and progressed into a functional rehabilitation program. Assessments of muscle size and function were performed using magnetic resonance imaging and included the measurement of cross-sectional areas of MF, psoas, and quadratus lumborum muscles and the change in trunk cross-sectional area due to voluntarily contracting the transversus abdominis muscle. Injury data were obtained from club records. Informed consent was obtained from all study participants. A smaller size of the MF muscle (odds ratio [OR] = 2.38) or quadratus lumborum muscle (OR = 2.17) was predictive of lower limb injury in the playing season. At the time point when one group of players had not received the intervention (n = 14), comparisons were made with the combined groups who had received the intervention (n = 32). The risk of sustaining a severe injury was lower for those players who received the motor control intervention (OR = 0.09). Although there are many factors associated with injuries in AFL, motor control training may provide a useful addition to strategies aimed at reducing lower limb injuries.

A Prospective Epidemiological Study of Injuries in Japanese National Tournament-Level Badminton Players From Junior High School to University

PubMed Central

Miyake, Eiji; Yatsunami, Mitsunobu; Kurabayashi, Jun; Teruya, Koji; Sekine, Yasuhiro; Endo, Tatsuaki; Nishida, Ryuichiro; Takano, Nao; Sato, Seiko; Jae Kyung, Han

2016-01-01

Background: Injury prevention programs have recently been created for various sports. However, a longitudinal study on badminton injuries, as assessed by a team’s dedicated medical staff, at the gymnasium has not been performed. Objectives: We aimed to perform the first such study to measure the injury incidence, severity and type as the first step in creating a badminton injury prevention program. Patients and Methods: A prospective, longitudinal survey was conducted between April 2012 and March 2013 with 133 national tournament-level badminton players from junior high school to university in Japan with the teams’ physical therapists at the gymnasium. Injury incidence was measured as the injury rate (IR) for every 1,000 hour (1000 hour) and IR for every 1,000 athlete exposures (1000 AE). Severity was classified in 5 levels by the number of days the athlete was absent from practice or matches. Injury types were categorized as trauma or overuse. Results: Practice (IR) (1,000 hour) was significantly higher in female players than in male players; the rates increased with increasing age. IR (1,000 AE) was significantly higher in matches than in practice in both sexes of all ages, except for female junior high school students and injuries were most frequent for high school students in matches. The majority of the injuries were slight (83.8%); overuse injuries occurred approximately 3 times more than trauma. Conclusions: This is the first study in which medical staff assessed injuries in badminton, providing value through benchmark data. Injury prevention programs are particularly necessary for female university students in practice and high school students in matches. PMID:27217933

Is there a relationship between the playing position of soccer players and their food and macronutrient intake?

PubMed

Iglesias-Gutiérrez, Eduardo; García, Angela; García-Zapico, Pedro; Pérez-Landaluce, Javier; Patterson, Angeles M; García-Rovés, Pablo Miguel

2012-04-01

Many authors have proposed the necessity of the design and implementation of dietary and nutrition education programs for soccer players, although little information is available about the determinants of food selection and nutrient intake. The aim of this study was to evaluate the nutritional intake and eating patterns of soccer players according to their playing position in the team. Eighty-seven young male soccer players (aged 16-21 years) were recruited from the junior teams of a Spanish First Division Soccer League Club and divided into 6 positional categories (goalkeepers, full-backs, centre-backs, midfielders, wingers, and forwards). Body composition (height, weight, and body fat), performance in soccer-specific tests (jumping, sprinting, and intermittent endurance), and dietary intake (weighed food intake method) were assessed. A spontaneous higher carbohydrate intake was observed for full-backs, midfielders, and wingers (g·kg(-1) body mass: 4.9 ± 1.0, 4.9 ± 1.3, 4.9 ± 0.8; % of energy intake: 47 ± 5, 46 ± 6, 46 ± 4), compared with goalkeepers and centre-backs (g·kg(-1) of body mass: 3.9 ± 1.0, 4.3 ± 1.1; % of energy intake: 44 ± 3, 42 ± 4). These differences were related to food selection patterns, and a higher contribution to daily energy intake of cereals, derivatives, and potatoes was observed between full-backs compared with goalkeepers and centre-backs (33% vs. 27% and 25%). The magnitude of these differences is limited considering the whole diet, and an inadequate nutrient intake were observed in most individuals of every group. The design and implementation of nutrition intervention programs, taking into consideration positional differences in nutritional intake, would be useful for these players.

Personal Food Systems of Male Collegiate Football Players: A Grounded Theory Investigation

PubMed Central

Long, Doug; Perry, Christina; Unruh, Scott A.; Lewis, Nancy; Stanek-Krogstrand, Kaye

2011-01-01

Context: Factors that affect food choices include the physical and social environments, quality, quantity, perceived healthfulness, and convenience. The personal food choice process was defined as the procedures used by athletes for making food choices, including the weighing and balancing of activities of daily life, physical well-being, convenience, monetary resources, and social relationships. Objective: To develop a theoretical model explaining the personal food choice processes of collegiate football players. Design: Qualitative study. Setting: National Collegiate Athletic Association Division II football program. Patients or Other Participants: Fifteen football players were purposefully sampled to represent various positions, years of athletic eligibility, and ethnic backgrounds. Data Collection and Analysis: For text data collection, we used predetermined, open-ended questions. Data were analyzed using the constant comparison method. The athletes' words were used to label and describe their interactions and experiences with the food choice process. Member checks and an external audit were conducted by a qualitative methodologist and a nutrition specialist, and the findings were triangulated with the current literature to ensure trustworthiness of the text data. Results: Time was the core category and yielded a cyclic graphic of a theoretical model for the food choice system. Planning hydration, macronutrient strategies, snacks, and healthful food choices emerged as themes. Conclusions: The athletes planned meals and snacks around their academic and athletic schedules while attempting to consume foods identified as healthful. Healthful foods were generally lower in fat but high in preferred macronutrients. High-protein foods were the players' primary goal; carbohydrate consumption was secondary. The athletes had established plans to maintain hydration. Professionals may use these findings to implement educational programs on food choices for football players. PMID:22488196

Efficacy of the National Football League-225 Test to Track Changes in One Repetition Maximum Bench Press After Training in National Collegiate Athletic Association Division IA Football Players.

PubMed

Mann, J Bryan; Ivey, Pat A; Stoner, Josh D; Mayhew, Jerry L; Brechue, William F

2015-11-01

Numerous investigations have attested to the efficacy of the National Football League (NFL)-225 test to estimate one repetition maximum (1RM) bench press. However, no studies have assessed the efficacy of the test to track changes in strength across a training program. The purpose of this study was to determine the accuracy of the NFL-225 test for determining the change in 1RM bench press in National Collegiate Athletic Association Division IA college football players after training. Over a 4-year period, players (n = 203) were assessed before and after a 6-week off-season resistance program for 1RM bench press and repetitions completed with 102.3 kg (225 lbs). Test sessions typically occurred within 1 week of each other. Players significantly increased 1RM by 4.2 ± 8.6 kg and NFL-225 repetitions by 0.9 ± 2.3, although the effect size (ES) for each was trivial (ES = 0.03 and 0.07, respectively). National Football League 225 prediction equations had higher correlations with 1RM before training (intraclass correlation coefficient [ICC] = 0.95) than after training (ICC = 0.75). The correlation between the change in NFL-225 repetitions and change in 1RM was low and negative (r = -0.22, p < 0.02). Short-term heavy resistance training may alter the association between muscular strength and muscular endurance in college football players and render the NFL-225 test less effective in predicting the change in 1RM bench press strength after short-term training.

Short-term moderate intensive high volume training program provides aerobic endurance benefit in wheelchair basketball players.

PubMed

Skucas, Kestutis; Pokvytyte, Vaida

2017-04-01

The aim of this paper was to investigate the effect of short-term period, moderate intensity and high volume endurance training on physiological variables in elite wheelchair basketball players. Eight wheelchair basketball players were examined. The subjects participated in a two-week intervention program of mainly two training types: wheelchair basketball and wheelchair driving endurance training. The subjects performed the continuously increasing cycling exercise (CCE) at the constant 60 rpm arm cranking speed at the beginning of the program and after two weeks of the program. The initial workload was 20 W, then the workload was increased by 2 W every 5 seconds until fatigue. The post training of the wheelchair basketball group in the study showed a significant improvement in the peak oxygen uptake (VO2peak) and the peak power output (POpeak). VO2peak increased by 9% from 2.32±0.16 L/min to 2.53±0.2 L/min (P<0.05). POpeak increased by 28% from 141.75±14.23 W, to 181.63±26.3 W (P<0.05). The pre-training and post training test power output (PO [w]), relative power output (PO [w/kg]) increased significantly in all zones of energy production. In conclusion, this study indicated that the wheelchair basketball squad had relatively high levels of aerobic fitness prior to participating in the endurance training program. Nevertheless, the high-volume, moderate-intensity, short-term training program, which evolved over the two-weeks period, resulted in the improvement of the athlete's aerobic endurance. The ventilatory threshold (VT) and the second ventilatory threshold (VT2) are good markers for aerobic capacity of wheelchair athletes.

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.

Self-reported Concussion History and Sensorimotor Tests Predict Head/Neck Injuries.

PubMed

Hides, Julie A; Franettovich Smith, Melinda M; Mendis, M Dilani; Treleaven, Julia; Rotstein, Andrew H; Sexton, Christopher T; Low Choy, Nancy; McCrory, Paul

2017-12-01

Sport-related concussion (SRC) is a risk for players involved in high-impact, collision sports. A history of SRC is a risk factor for future concussions, but the mechanisms underlying this are unknown. Despite evidence that most visible signs and symptoms associated with sports concussion resolve within 7-10 d, it has been proposed that subclinical loss of neuromuscular control and impaired motor functioning may persist and be associated with further injury. Alternatively, indicators of poor sensorimotor performance could be independent risk factors. This study investigated if a history of SRC and/or preseason sensorimotor performance predicted season head/neck injuries. A total of 190 male rugby league, rugby union, and Australian Football League players participated. Preseason assessments included self-report of SRC within the previous 12 months and a suite of measures of sensorimotor function (balance, vestibular function, cervical proprioception, and trunk muscle function). Head/neck injury data were collected in the playing season. Forty-seven players (25%) reported a history of SRC. A history of concussion was related to changes in size and contraction of trunk muscles. Twenty-two (11.6%) players sustained a head/neck injury during the playing season, of which, 14 (63.6%) players had a history of SRC. Predictors of in-season head/neck injuries included history of SRC, trunk muscle function, and cervical proprioceptive errors. Five risk factors were identified, and players with three or more of these had 14 times greater risk of sustaining a season neck/head injury (sensitivity of 75% and specificity of 82.5%) than did players with two or fewer risk factors. The modifiable risk factors identified could be used to screen football players in the preseason and guide the development of exercise programs aimed at injury reduction.

Biomechanical and functional indicators in male semiprofessional soccer players with increased hip alpha angles vs. amateur soccer players.

PubMed

Lahner, Matthias; von Schulze Pellengahr, Christoph; Walter, Philipp Alexander; Lukas, Carsten; Falarzik, Andreas; Daniilidis, Kiriakos; von Engelhardt, Lars Victor; Abraham, Christoph; Hennig, Ewald M; Hagen, Marco

2014-03-16

Femoroacetabular impingement (FAI) is predominant in young male athletes, but not much is known about gait differences in cases of increased hip alpha angles. In our study, the hip alpha angle of Nötzli of soccer players was quantified on the basis of magnetic resonance imaging (MRI) with axial oblique sequences. The aim of the current study was to compare the rearfoot motion and plantar pressure in male semiprofessional soccer players with increased alpha angles to age-matched amateur soccer players. In a prospective analysis, male semiprofessional and amateur soccer players had an MRI of the right hip to measure the alpha angle of Nötzli. In a biomechanical laboratory setting, 14 of these participants in each group ran in two shoe conditions. Simultaneously in-shoe pressure distribution, tibial acceleration, and rearfoot motion measurements of the right foot were performed. In the semiprofessional soccer group, the mean value of the alpha angle of group was 55.1 ± 6.58° (range 43.2-76.6°) and 51.6 ± 4.43° (range 41.9-58.8°) in the amateur group. In both shoe conditions, we found a significant difference between the two groups concerning the ground reaction forces, tibial acceleration, rearfoot motion and plantar pressure parameters (P < 0.01, P < 0.05, P = 0.04). Maximum rearfoot motion is about 22% lower in the semiprofessional group compared to the amateur group in both shoe conditions. This study confirmed that semiprofessional soccer players with increased alpha angles showed differences in gait kinematics compared to the amateur group. These findings support the need for a screening program for competitive soccer players. In cases of a conspicuous gait analysis and symptomatic hip pain, FAI must be ruled out by further diagnostic tests.

Injury Patterns, Physiological Profile, and Performance in University Rugby Union.

PubMed

Ball, Shane; Halaki, Mark; Sharp, Tristan; Orr, Rhonda

2018-01-01

Rugby union is a physically demanding collision sport with high injury rates. There is a common perception that higher training loads result in greater injury risk in field-based sports. To determine injury, anthropometric, and physical-performance characteristics in junior rugby union players and investigate the interaction between training load and injury across a competitive season. Prospective cohort study. Fifty-one players (age 19.2 ± 0.7 y) from an under-20 university rugby union team (forwards, n = 27; backs, n = 24) participated in a study conducted over a competition season. Training load, injury characteristics, anthropometry, physiological performance, and match time-loss injury incidence were observed. Backs had significantly lower body mass (ES [95% CI] = 1.6 [0.9, 2.2]), skinfold thickness (ES = 1.1 [0.5, 1.7]), strength (squat ES = 0.6 [0.0, 1.2], deadlift ES = 0.6 [0.0, 1.1], bench press ES = 0.9 [0.4, 1.5]), lower-body power (ES = 0.4 [-0.2, 1.0]), and higher maximal aerobic capacity (ES = -0.3 [-0.8, 0.3]) than forwards. Match injury incidence was 107.3 injuries/1000 player hours (forwards 91.4/1000, backs 125.5/1000) during preseason and 110.7 injuries/1000 player hours (forwards 124.1/1000, backs 95.2/1000) during in-season. Forwards showed higher incidence of joint and ligament (P = .049) and upper-limb (P = .011) injuries than backs. No significant relationship between overall training load and match injury incidence was found. However, lower match injury incidence was associated with higher weekly training volume in backs (P = .007). Positional differences in body composition, performance, injury characteristics, and match injury patterns were identified in junior university rugby union players, indicating the need for position-specific training programs to reduce risk of injury.

Motor Function in Former Professional Football Players with History of Multiple Concussions.

PubMed

Tarazi, Apameh; Tator, Charles H; Wennberg, Richard; Ebraheem, Ahmed; Green, Robin E A; Collela, Brenda; Saverino, Christina; Khodadadi, Mozghan; Misquitta, Karen; Tartaglia, Maria Carmela

2018-04-15

The objective of this study was to assess the incidence of motor impairment in former professional Canadian Football League (ex-CFL) players with multiple concussions. We investigated motor symptoms and signs in 45 ex-CFL players with multiple concussions and 25 age- and education-matched healthy controls with no history of concussion. Neurological assessment included items from the SCAT3 (Sport Concussion Assessment Tool 3) and the Unified Parkinson's Disease Rating Scale part III (UPDRS-Part III). A performance-based measurement of manual motor function was undertaken using the Grooved Pegboard test. Cognition was measured with patient-reported outcomes for memory, executive and behavioral symptoms as well as performance-based measures of memory and executive function. Symptoms of anxiety and depression were measured using the Personality Assessment Inventory. There was no significant difference between the ex-CFL players and controls on the UPDRS-Part III scores, and neither group reported clinically significant motor complaints. Ex-CFL players did not perform differently from control subjects on the Grooved Pegboard test. In contrast, with regard to cognitive and mood testing, players were more symptomatic: The ex-CFL players reported significantly more memory (77.8% vs. 16%, respectively, p < 0.001), executive (53.3% vs. 8%, respectively, p < 0.001), and behavioral symptoms (66.7% vs. 20%, respectively, p < 0.001). No significant differences were found when comparing ex-CFL players and controls in performance on memory and executive tests. In summary, in a group of retired CFL players who self-reported declines in memory, executive and behavioral symptoms, no motor symptoms were reported and no motor signs were detected.

ULTRASONOGRAPHIC ASSESSMENT OF NECK MUSCULAR SIZE AND RANGE OF MOTION IN RUGBY PLAYERS.

PubMed

Hemelryck, Walter; Calistri, Josselin; Papadopoulou, Virginie; Theunissen, Sigrid; Dugardeyn, Christian; Balestra, Costantino

2018-02-01

World Rugby Union laws are constantly evolving towards stringent injury-prevention, particularly for contested scrums, since front row players are most at risk of cervical spine injuries. Recently, some countries have also introduced tailored training programs and minimum performance requirements for playing in the front row. Nevertheless, these approaches lack an objective assessment of each cervical muscle that would provide protective support. Since front row players are the most at risk for cervical spine injuries due to the specific type of contact during scrums, the purpose of this study was to ascertain whether significant differences exist in neck muscle size and range of motion between front row players and players of other positions, across playing categories. Cross-sectional controlled laboratory study. 129 sub-elite male subjects from various first-team squads of Belgian Rugby clubs were recruited. Subjects were grouped according to age: Junior (J) < 19 years old, Senior (S) 19 to 35 years old and Veteran (V) > 35 years old; as well as playing position: Front row players (J = 10, S = 12, V = 11 subjects), (Rest of the) pack (J = 12, S = 12, V = 10), backs (J = 10, S = 11, V = 11). An age-matched control group of non-rugby players was also recruited (J = 10, S = 10, V = 10).For each subject, the total neck circumference (NC) and the cervical range of motion (CROM) were measured. In addition, the thickness of the trapezius (T), splenius capitis (SCa), semispinalis capitis (SCb), semispinalis cervicis (SPC), sternocleidomastoid muscles (SCOM), and the total thickness of all four structures (TT), were measured using ultrasonography. In each age category, compared to controls, rugby players were found to have decreased CROM, an increase in neck circumference (NC), and increased total thickness (TT), trapezius (T), semispinalis capitis (SCb) and sternocleidomastoid muscles (SCOM) sizes. For junior players, the thickness of the semispinalis cervicis (SPC) was also increased compared to controls. The CROM was decreased in front row players compared to pack and back players for all age categories; Front row seniors also showed an increase in trapezius (T), splenius capitis (SCa), semispinalis capitis (SCb) and total thickness (TT), compared to back players. In regard of the differences in cervical values found between player positions, the implementation of both range of motion and echography muscle thickness assessments could serve to create an additional measurement for all front row players, that could complement current pre-participation screening used by rugby federations by objectively monitoring muscular size and motion amplitude around the cervical spine.

Neural correlates of receiving an apology and active forgiveness: an FMRI study.

PubMed

Strang, Sabrina; Utikal, Verena; Fischbacher, Urs; Weber, Bernd; Falk, Armin

2014-01-01

Interpersonal conflicts are a common element of many social relationships. One possible process in rebuilding social relationships is the act of apologizing. Behavioral studies have shown that apologies promote forgiveness. However, the neural bases of receiving an apology and forgiveness are still unknown. Hence, the aim of the present fMRI study was to investigate brain processes involved in receiving an apology and active forgiveness of an ambiguous offense. We asked one group of participants (player A) to make decisions, which were either positive or negative for another group of participants (player B). The intention of player A was ambiguous to player B. In case of a negative impact, participants in the role of player A could send an apology message to participants in the role of player B. Subsequently players B were asked whether they wanted to forgive player A for making a decision with negative consequences. We found that receiving an apology yielded activation in the left inferior frontal gyrus, the left middle temporal gyrus, and left angular gyrus. In line with previous research we found that forgiving judgments activated the right angular gyrus.

Conveying population education through games.

PubMed

1987-01-01

Games are extremely useful for conveying population education messages because they are entertaining, because they involve the players in the learning situation, and because, by compressing space and time, they enable the players to perceive the effects of future events on their own lives. One teaching game, called "Futures Wheel," enables the players to move step by step from an abstract real-world situation to its impact on their own lives. Another game, called "Card Game on Family Welfare," is played by 4 players using cards illustrating such things as preparation for marriage, planned families, small families, responsible parenthood, and women's roles. 24 of the 25 cards dealt to the players have matching pictures on a base sheet. The player who loses, i.e., cannot find a match for his last card, is holding the card which displays an unhappy big family.

Effects of a combined resistance-plyometric training program on muscular strength, running economy, and Vo2peak in division I female soccer players.

PubMed

Grieco, Carmine R; Cortes, Nelson; Greska, Eric K; Lucci, Shawn; Onate, James A

2012-09-01

Resistance and plyometric training programs have demonstrated consistent improvements in running economy (RE) in trained and untrained adults in the absence of improvements in maximal oxygen consumption. The purpose of this study was to investigate the effect of a 10-week combined resistance-plyometric training program on the RE and V[Combining Dot Above]O2max in female soccer players. Fifteen Division 1A female soccer players (age 19.0 ± 0.7 years; height 1.67 ± 0.1 m; weight 61.7 ± 8.1 kg) performed a treadmill test for V[Combining Dot Above]O2max and RE at the end of a competitive season (PRE) and after a 10-week training program (POST). Isometric strength was measured in knee flexion and extension. Resistance training was conducted 2 d·wk on nonconsecutive days; plyometric training was conducted separately on different nonconsecutive days. Eleven subjects were included in the PRE-POST analysis (age 19.0 ± 0.8 years; height 1.67 ± 0.5 m; weight 59.9 ± 6.7 kg). Descriptive statistics were compared using analysis of variance with repeated measures with a Bonferroni adjustment, and significance was set at p < 0.05. A significant increase occurred after training in the V[Combining Dot Above]O2peak (10.5%; p = 0.008), time to fatigue (6.9%; p = 0.017), and interpolated maximal speed (3.6%; p = 0.016), despite there being a decrease in the maximal respiratory exchange ratio (2.9%; p = 0.001). There was no significant change in the RE at 9 km·h; however, there was a significant decrease in the percentage of the V[Combining Dot Above]O2peak at 9 km·h (-5.6%; p = 0.02). Maximal isometric strength of knee flexors and extensors did not change. The results suggest a plyometric-agility training program may increase the V[Combining Dot Above]O2peak in female soccer players; however, the effect on RE was equivocal.

Evaluation of anthropometric, physiological, and skill-related tests for talent identification in female field hockey.

PubMed

Keogh, Justin W L; Weber, Clare L; Dalton, Carl T

2003-06-01

The purpose of the present study was to develop an effective testing battery for female field hockey by using anthropometric, physiological, and skill-related tests to distinguish between regional representative (Rep, n = 35) and local club level (Club, n = 39) female field hockey players. Rep players were significantly leaner and recorded faster times for the 10-m and 40-m sprints as well as the Illinois Agility Run (with and without dribbling a hockey ball). Rep players also had greater aerobic and lower body muscular power and were more accurate in the shooting accuracy test, p < 0.05. No significant differences between groups were evident for height, body mass, speed decrement in 6 x 40-m repeated sprints, handgrip strength, or pushing speed. These results indicate that %BF, sprinting speed, agility, dribbling control, aerobic and muscular power, and shooting accuracy can distinguish between female field hockey players of varying standards. Therefore talent identification programs for female field hockey should include assessments of these physical parameters.

Comparison of the backward overhead medicine ball throw to power production in college football players.

PubMed

Mayhew, Jerry L; Bird, Michael; Cole, Mary L; Koch, Alex J; Jacques, Jeff A; Ware, John S; Buford, Brittney N; Fletcher, Kate M

2005-08-01

The purpose of this study was to determine the relationship of the backward overhead medicine ball (BOMB) throw to power production in college football players. Forty National Collegiate Athletic Association Division II college football players were studied at the end of an 8-week off-season conditioning program for power output determined from a countermovement vertical jump on a force plate and for maximal distance in the standing BOMB throw. Although the reliability of the BOMB test was high (interclass correlation coefficient = 0.86), there was a significant learning effect across 3 trials (p < 0.01). Peak and average powers generated during the vertical jump correlated moderately but significantly with the best BOMB throw distance (r = 0.59 and 0.63, respectively). Considering power relative to body mass or lean body mass failed to produce significant correlations with BOMB throw distance (r = 0.27 and 0.28, respectively). Therefore, the BOMB throw may have limited potential as a predictor of total body explosive power in college football players.

Implementation of a nutrition education program in a handball team; consequences on nutritional status.

PubMed

Molina-López, Jorge; Molina, José Manuel; Chirosa, Luis Javier; Florea, Daniela; Sáez, Laura; Jiménez, Jorge; Planells, Paloma; Pérez de la Cruz, Antonio; Planells, Elena

2013-01-01

To evaluate nutritional status and dietary habits after implementation of a nutritional education program in professional handball players. Longitudinal study of 14 handball players evaluated with 72-h recall, a questionnaire on food consumption and anthropometric measures during 4 months. The intervention consisted of a nutrition education program. Energy intake was consistently below the recommended allowances. Macronutrient intakes as a percentage of total energy intake were below the recommended allowances for carbohydrates, and above recommended allowances for fats. Nutritional education was followed by a significant increase (p < 0.01) in total energy and macronutrient intakes, with no significant changes in macronutrient or micronutrient intakes after adjustment for energy intake. The imbalance in nutrient intake in handball players suggests that detailed re-analysis is needed to determine specific recommendations for this population. Nutritional education with continuous follow-up to monitor athletes' dietary habits may lead them to adopt appropriate nutritional habits to optimize dietary intakes. The lack of specific recommendations for micronutrient intakes in athletes leads to confusion regarding appropriate intakes; biochemical tests that yield normal values (albeit approaching cut-off values for deficiency) may disguise deficient status for some nutrients when strenuous exercise is involved. In-depth studies with nutrition education programs that include long-term follow-up are advisable to avoid deficiencies that can lead to irreversible damage in competitive athletes. Copyright © AULA MEDICA EDICIONES 2013. Published by AULA MEDICA. All rights reserved.

The role for public funding of faith-based organizations delivering behavioral health services: guideposts for monitoring and evaluation.

PubMed

Kramer, Fredrica D

2010-12-01

The paper reviews policies promoting faith-based organizations' (FBO) participation in publicly-funded programs since the Charitable Choice statute was enacted during the Clinton administration and then additional faith-based initiatives were implemented by the Bush administration. The paper focuses on research findings on FBO participation in publicly-funded human service programs under these policies. It then proposes a framework for evaluation to assess the appropriateness of public funding for behavioral health services delivered by FBOs, in order to address: (1) the programmatic and systemic effects resulting from the infusion of new players from the faith community, and the consequences to the profile of services and who gets served; and (2) the content and effectiveness of faith-infused services as a basis for identifying interventions appropriate for public funding. The analysis considers classification issues, theoretical bases of measured effects of faith-infused services, and the transferability of faith-based interventions across religious and secular applications in order to satisfy constitutional issues and client choice.

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

PubMed

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

2016-10-01

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

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.

Evolutionary games in the multiverse.

PubMed

Gokhale, Chaitanya S; Traulsen, Arne

2010-03-23

Evolutionary game dynamics of two players with two strategies has been studied in great detail. These games have been used to model many biologically relevant scenarios, ranging from social dilemmas in mammals to microbial diversity. Some of these games may, in fact, take place between a number of individuals and not just between two. Here we address one-shot games with multiple players. As long as we have only two strategies, many results from two-player games can be generalized to multiple players. For games with multiple players and more than two strategies, we show that statements derived for pairwise interactions no longer hold. For two-player games with any number of strategies there can be at most one isolated internal equilibrium. For any number of players with any number of strategies , there can be at most isolated internal equilibria. Multiplayer games show a great dynamical complexity that cannot be captured based on pairwise interactions. Our results hold for any game and can easily be applied to specific cases, such as public goods games or multiplayer stag hunts.

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.

[Financing healthcare in low-income countries: recurring questions, new challenges].

PubMed

Audibert, M; Mathonnat, J; de Roodenbeke, E

2004-01-01

Healthcare financing policies in low-income countries have gone through three successive phases. In the first phase the dominant approach was based on free access to healthcare and focused first on development of vertical programs and then on the necessity of providing primary care to all. While maintaining the emphasis on accessibility to primary care, the second policy phase introduced user fees and attempted to integrate healthcare programs into district-based healthcare structures. The third phase has been strongly influenced by the relationship between healthcare and development and the Millenium Objectives and places strong emphasis on necessity of developing insurance schemes. Recent studies on the relationship between healthcare spending and health status indicate that the efficiency and effectiveness of healthcare spending plays a more determinant role than the amount. At the same time an effort is being made to develop synergy between the different players in the health care systems and to clarify the role of each player by hinging financing decisions on operating criteria such as "public welfare", externalities, catastrophic costs, and equity. Although many countries have made significant progress, there are still several lagging areas, i.e., coverage for the poorest segment of the population (despite the rhetoric), follow-up of financing, and governance. Increasing external aid already initiated by several states may have a non-negligible impact on the macroeconomic balance. Since these changes could lead to adverse effects on health, there is a need to implement careful non-dogmatic policies.

War-gaming application for future space systems acquisition

NASA Astrophysics Data System (ADS)

Nguyen, Tien M.; Guillen, Andy T.

2016-05-01

Recently the U.S. Department of Defense (DOD) released the Defense Innovation Initiative (DII) [1] to focus DOD on five key aspects; Aspect #1: Recruit talented and innovative people, Aspect #2: Reinvigorate war-gaming, Aspect #3: Initiate long-range research and development programs, Aspect #4: Make DOD practices more innovative, and Aspect #5: Advance technology and new operational concepts. Per DII instruction, this paper concentrates on Aspect #2 and Aspect #4 by reinvigorating the war-gaming effort with a focus on an innovative approach for developing the optimum Program and Technical Baselines (PTBs) and their corresponding optimum acquisition strategies for acquiring future space systems. The paper describes a unified approach for applying the war-gaming concept for future DOD acquisition of space systems. The proposed approach includes a Unified Game-based Acquisition Framework (UGAF) and an Advanced Game-Based Mathematical Framework (AGMF) using Bayesian war-gaming engines to optimize PTB solutions and select the corresponding optimum acquisition strategies for acquiring a space system. The framework defines the action space for all players with a complete description of the elements associated with the games, including Department of Defense Acquisition Authority (DAA), stakeholders, warfighters, and potential contractors, War-Gaming Engines (WGEs) played by DAA, WGEs played by Contractor (KTR), and the players' Payoff and Cost functions (PCFs). The AGMF presented here addresses both complete and incomplete information cases. The proposed framework provides a recipe for the DAA and USAF-Space and Missile Systems Center (SMC) to acquire future space systems optimally.

Are Canadian-born Major League Baseball players more likely to bat left-handed? A partial test of the hockey-influence on batting hypothesis.

PubMed

Cairney, John; Chirico, Daniele; Li, Yao-Chuen; Bremer, Emily; Graham, Jeffrey D

2018-01-01

It has been suggested that Canadian-born Major League Baseball (MLB) players are more likely to bat left-handed, possibly owing to the fact that they learn to play ice hockey before baseball, and that there is no clear hand-preference when shooting with a hockey stick; approximately half of all ice hockey players shoot left. We constructed a database on active (i.e., October, 2016) MLB players from four countries/regions based on place of birth (Canada, United States of America [USA], Dominican Republic and South Asia [i.e., Japan, Taiwan and South Korea]), including information on which hand they use to bat and throw. We also extracted information on all Canadian-born MLB players, dating back to 1917. Our results confirm that the proportion of left-handed batters born in Canada is higher when compared to the other countries selected; also, since 1917, the proportion of Canadian MLB players who bat left has been consistently higher than the league average. We also compared the proportion of left-handed batters in Canada with players born in states in the USA grouped into high, average and low based on hockey participation. The proportion of MLB players born in states with a high level of hockey participation were more likely to bat left, although the differences were significant at trend level only (p < .10). Lastly, we found that while Canadians were more likely to bat left-handed, this did not correspond with a greater left-hand dominance, as determined by throwing hand. In conclusion, the present study confirms that Canadian-born MLB players are more likely to bat left-handed when compared to American, Dominican Republic and South Asian-born MLB players, providing partial support for the hockey influence on batting hypothesis.

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).

Preventive Effects of Eccentric Training on Acute Hamstring Muscle Injury in Professional Baseball

PubMed Central

Seagrave, Richard A.; Perez, Luis; McQueeney, Sean; Toby, E. Bruce; Key, Vincent; Nelson, Joshua D.

2014-01-01

Background: Hamstring injuries are the second most common injury causing missed days in professional baseball field players. Recent studies have shown the preventive benefit of eccentric conditioning on the hamstring muscle group in injury prevention. Specifically, Nordic-type exercises have been shown to decrease the incidence of acute hamstring injuries in professional athletes. Purpose: This was a prospective study performed in coordination with a single Major League Baseball (MLB) organization (major and minor league teams) that targeted the effects of Nordic exercises on the incidence of acute hamstring injuries in the professional-level baseball player. Study Design: Prospective cohort study; Level of evidence, 2. Methods: The daily workouts of 283 professional baseball players throughout all levels of a single MLB organization were prospectively recorded. The intervention group participated in the Nordic exercise program and was compared with a randomly selected control group of professional athletes within the organization not participating in the exercise program. The incidence of hamstring injuries in both groups was compared, and the total number of days missed due to injury was compared with the 2 previous seasons. Results: There were 10 hamstring injuries that occurred during the 2012 season among the 283 professional athletes that required removal from play. There were no injuries that occurred in the intervention group (n = 65, 0.00%; P = .0381). The number needed to treat (NNT) to prevent 1 hamstring injury was 11.3. The average repetitions per week of the injured group were assessed at multiple time points (2, 4, 6, and total weeks) prior to injury. There were significantly fewer repetitions per week performed in the injured group at all time points compared with overall average repetitions per week in the noninjured group (P = .0459, .0127, .0164, and .0299, respectively). After beginning the Nordic exercise program, there were 136 total days missed due to a hamstring injury during the 2012 season. This number was less than the 2011 season (273 days missed) and the 2010 season (309 days missed). Conclusion: Study results indicate the initiation of Nordic hamstring exercises may decrease the incidence of acute hamstring injuries and potentially decrease the total number of days missed due to injury in professional baseball players. Clinical Relevance: The financial and competitive interest in professional baseball players is of large importance to the player, team, and fans. Prevention of injuries is as important to all parties involved as the treatment and rehabilitation following an injury. This prospective study shows the initiation of a simple, free exercise can reduce the incidence of hamstring injury in the professional-level baseball player. PMID:26535336

Tanner-Whitehouse Skeletal Ages in Male Youth Soccer Players: TW2 or TW3?

PubMed

Malina, Robert M; Coelho-E-Silva, Manuel J; Figueiredo, António J; Philippaerts, Renaat M; Hirose, Norikazu; Peña Reyes, Maria Eugenia; Gilli, Giulio; Benso, Andrea; Vaeyens, Roel; Deprez, Dieter; Guglielmo, Luiz F; Buranarugsa, Rojapon

2018-04-01

The Tanner-Whitehouse radius-ulna-short bone protocol (TW2 RUS) for the assessment of skeletal age (SA) is widely used to estimate the biological (skeletal) maturity status of children and adolescents. The scale for converting TW RUS ratings to an SA has been revised (TW3 RUS) and has implications for studies of youth athletes in age-group sports. The aim of this study was to compare TW2 and TW3 RUS SAs in an international sample of male youth soccer players and to compare distributions of players by maturity status defined by each SA protocol. SA assessments with the TW RUS method were collated for 1831 male soccer players aged 11-17 years from eight countries. RUS scores were converted to TW2 and TW3 SAs using the appropriate tables. SAs were related to chronological age (CA) in individual athletes and compared by CA groups. The difference of SA minus CA with TW2 SA and with TW3 SA was used to classify players as late, average, or early maturing with each method. Concordance of maturity classifications was evaluated with Cohen's Kappa coefficients. For the same RUS score, TW3 SAs were systematically and substantially reduced compared with TW2 SAs; mean differences by CA group ranged from - 0.97 to - 1.16 years. Kappa coefficients indicated at best fair concordance of TW2 and TW3 maturity classifications. Across the age range, 42% of players classified as average with TW2 SA were classified as late with TW3 SA, and 64% of players classified as early with TW2 SA were classified as average with TW3 SA. TW3 SAs were systematically lower than corresponding TW2 SAs in male youth soccer players. The differences between scales have major implications for the classification of players by maturity status, which is central to some talent development programs.

Soccer-Specific Warm-Up and Lower Extremity Injury Rates in Collegiate Male Soccer Players

PubMed Central

Grooms, Dustin R.; Palmer, Thomas; Onate, James A.; Myer, Gregory D.; Grindstaff, Terry

2013-01-01

Context: A number of comprehensive injury-prevention programs have demonstrated injury risk-reduction effects but have had limited adoption across athletic settings. This may be due to program noncompliance, minimal exercise supervision, lack of exercise progression, and sport specificity. A soccer-specific program described as the F-MARC 11+ was developed by an expert group in association with the Federation Internationale de Football Association (FIFA) Medical Assessment and Research Centre (F-MARC) to require minimal equipment and implementation as part of regular soccer training. The F-MARC 11+ has been shown to reduce injury risk in youth female soccer players but has not been evaluated in an American male collegiate population. Objective: To investigate the effects of a soccer-specific warm-up program (F-MARC 11+) on lower extremity injury incidence in male collegiate soccer players. Design: Cohort study. Setting: One American collegiate soccer team followed for 2 seasons. Patients or Other Participants: Forty-one male collegiate athletes aged 18–25 years. Intervention(s): The F-MARC 11+ program is a comprehensive warm-up program targeting muscular strength, body kinesthetic awareness, and neuromuscular control during static and dynamic movements. Training sessions and program progression were monitored by a certified athletic trainer. Main Outcome Measure(s): Lower extremity injury risk and time lost to lower extremity injury. Results: The injury rate in the referent season was 8.1 injuries per 1000 exposures with 291 days lost and 2.2 injuries per 1000 exposures and 52 days lost in the intervention season. The intervention season had reductions in the relative risk (RR) of lower extremity injury of 72% (RR = 0.28, 95% confidence interval = 0.09, 0.85) and time lost to lower extremity injury (P < .01). Conclusions: This F-MARC 11+ program reduced overall risk and severity of lower extremity injury compared with controls in collegiate-aged male soccer athletes. PMID:23848519

A 20-Year Comparison of Football-Related Injuries in American and Canadian Youth Aged 6 to 17 Years: A Replication Study.

PubMed

Keays, Glenn; Friedman, Debbie; Gagnon, Isabelle

2016-06-01

Introduction Little is known about Canadian youth football injuries. The objectives of this study were (a) to contrast the injuries in Canadian and American football players aged 6 to 17 years and (b) compare the injuries sustained during organized football with those in nonorganized football. Methods Using a retrospective cohort design based on data from the Canadian Hospitals Injury Reporting and Prevention Program and the National Electronic Injury Surveillance System a comparison of injuries was made. Results Trends in injuries were comparable. Proportions and odds of injuries were similar, except for a few exceptions. In Canada, more girls were injured and fractures were more prevalent. Compared with nonorganized football, organized football players were older, involved more males, and suffered more traumatic brain injuries and injuries to their lower extremities. Conclusion Canadian and American youth football injuries were similar. The type of football, be it organized or nonorganized, has an impact on injuries. © The Author(s) 2015.

Symptoms of common mental disorders and related stressors in Danish professional football and handball.

PubMed

Kilic, Özgür; Aoki, Haruhito; Haagensen, Rasmus; Jensen, Claus; Johnson, Urban; Kerkhoffs, Gino M M J; Gouttebarge, Vincent

2017-11-01

The aim of the study was twofold, namely (i) to determine the prevalence of symptoms of common mental disorders (CMDs) among current and retired professional football and handball players and (ii) to explore the relationship of psychosocial stressors with the outcome measures under study. A total of 1155 players were enrolled in an observational study based on a cross-sectional design. Questionnaires based on validated scales were set up and distributed among current and retired professional football and handball players by the Danish football and handball players' union. In professional football, the highest prevalence (4 weeks) of symptoms of CMDs was 18% and 19% for anxiety/depression among current and retired players, respectively. In professional handball, the highest prevalence (4 weeks) of symptoms of CMDs was 26% and 16% for anxiety/depression among current and retired players, respectively. For both the current and retired professional football and handball players, a higher number of severe injuries and recent adverse life events (LE) were related to the presence of symptoms of CMD. Players exposed to severe injuries and/or recent adverse LE were 20-50% times more likely to report symptoms of CMD. The results suggest that it is possible to recognize the population of professional athletes that are more likely to develop symptoms of CMD. This could create the opportunity to intervene preventively on athletes that suffered from severe injury and/or recent adverse LE that could lead to a faster and safer recovery and psychological readiness to return to play.

Superior compliance with a neuromuscular training programme is associated with fewer ACL injuries and fewer acute knee injuries in female adolescent football players: secondary analysis of an RCT.

PubMed

Hägglund, Martin; Atroshi, Isam; Wagner, Philippe; Waldén, Markus

2013-10-01

Little is known about the influence of compliance with neuromuscular training (NMT) on the knee injury rate in football. To evaluate team and player compliance with an NMT programme in adolescent female football and to study the association between compliance and acute knee injury rates. Prospective cohort study based on a cluster randomised controlled trial on players aged 12-17 years with 184 intervention teams (2471 players) and 157 control teams (2085 players). Exposure and acute time loss knee injuries were recorded. Team and player compliance was recorded by the coaches on a player attendance form. The intervention group was divided into tertiles of compliance. Injury rates were compared by calculating rate ratios (RRs) and 95% CIs using exact Poisson tests with the low-compliance tertile as reference. Seasonal compliance trends were analysed using linear regression. Players in the high-compliance tertile had an 88% reduction in the anterior cruciate ligament (ACL) injury rate (RR 0.12, 95% CI 0.01 to 0.85), whereas the rate in the control group players was not significantly different from those in the low-compliance tertile (RR 0.77, 95% CI 0.27 to 2.21). A significant deterioration occurred in team (b=-3.0% per month, 95% CI -5.2 to -0.8) and player (b=-5.0% per month, 95% CI -7.1 to -2.9) compliance over the season. Players with high compliance with the NMT programme had significantly reduced ACL injury rate compared with players with low compliance. Significant deterioration in team and player compliance occurred over the season.

Assessing Cognitive Performance in Badminton Players: A Reproducibility and Validity Study

PubMed Central

van de Water, Tanja; Faber, Irene; Elferink-Gemser, Marije

2017-01-01

Abstract Fast reaction and good inhibitory control are associated with elite sports performance. To evaluate the reproducibility and validity of a newly developed Badminton Reaction Inhibition Test (BRIT), fifteen elite (25 ± 4 years) and nine non-elite (24 ± 4 years) Dutch male badminton players participated in the study. The BRIT measured four components: domain-general reaction time, badminton-specific reaction time, domain-general inhibitory control and badminton-specific inhibitory control. Five participants were retested within three weeks on the badminton-specific components. Reproducibility was acceptable for badminton-specific reaction time (ICC = 0.626, CV = 6%) and for badminton-specific inhibitory control (ICC = 0.317, CV = 13%). Good construct validity was shown for badminton-specific reaction time discriminating between elite and non-elite players (F = 6.650, p < 0.05). Elite players did not outscore non-elite players on domain-general reaction time nor on both components of inhibitory control (p > 0.05). Concurrent validity for domain-general reaction time was good, as it was associated with a national ranking for elite (p = 0.70, p < 0.01) and non-elite (p = 0.70, p < 0.05) players. No relationship was found between the national ranking and badminton-specific reaction time, nor both components of inhibitory control (p > 0.05). In conclusion, reproducibility and validity of inhibitory control assessment was not confirmed, however, the BRIT appears a reproducible and valid measure of reaction time in badminton players. Reaction time measured with the BRIT may provide input for training programs aiming to improve badminton players’ performance. PMID:28210347

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.

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.

Analytic method for evaluating players' decisions in team sports: Applications to the soccer goalkeeper.

PubMed

Lamas, Leonardo; Drezner, Rene; Otranto, Guilherme; Barrera, Junior

2018-01-01

The aim of this study was to define a method for evaluating a player's decisions during a game based on the success probability of his actions and for analyzing the player strategy inferred from game actions. There were developed formal definitions of i) the stochastic process of player decisions in game situations and ii) the inference process of player strategy based on his game decisions. The method was applied to the context of soccer goalkeepers. A model of goalkeeper positioning, with geometric parameters and solutions to optimize his position based on the ball position and trajectory, was developed. The model was tested with a sample of 65 professional goalkeepers (28.8 ± 4.1 years old) playing for their national teams in 2010 and 2014 World Cups. The goalkeeper's decisions were compared to decisions from a large dataset of other goalkeepers, defining the probability of success in each game circumstance. There were assessed i) performance in a defined set of classes of game plays; ii) entropy of goalkeepers' decisions; and iii) the effect of goalkeepers' positioning updates on the outcome (save or goal). Goalkeepers' decisions were similar to the ones with the lowest probability of goal on the dataset. Goalkeepers' entropy varied between 24% and 71% of the maximum possible entropy. Positioning dynamics in the instants that preceded the shot indicated that, in goals and saves, goalkeepers optimized their position before the shot in 21.87% and 83.33% of the situations, respectively. These results validate a method to discriminate successful performance. In conclusion, this method enables a more precise assessment of a player's decision-making ability by consulting a representative dataset of equivalent actions to define the probability of his success. Therefore, it supports the evaluation of the player's decision separately from his technical skill execution, which overcomes the scientific challenge of discriminating the evaluation of a player's decision performance from the action result.

Modifying Rules of a Regular Girls Softball League to Facilitate the Inclusion of a Child with Severe Disabilities.

ERIC Educational Resources Information Center

Bernabe, Elaine A.; Block, Martin E.

1994-01-01

Coaches and players were assisted in modifying select rules of a girls' fast-pitch softball league so as to accommodate the skill limitations of a player with moderate to severe disabilities. The girl's batting average and on-base average indicated that modifications were effective. The player was well received by her teammates and other teams.…

Effects of Peer-Assessed Feedback, Goal Setting and a Group Contingency on Performance and Learning by 10-12-Year-Old Academy Soccer Players

ERIC Educational Resources Information Center

Holt, Josh E.; Kinchin, Gary; Clarke, Gill

2012-01-01

Background: Coaches developing young talent in team sports must maximise practice and learning of essential game skills and accurately and continuously assess the performance and potential of each player. Relative age effects highlight an erroneous process of initial and on-going player assessment, based largely on subjective opinions of game…

Polarization induced doped transistor

DOEpatents

Xing, Huili; Jena, Debdeep; Nomoto, Kazuki; Song, Bo; Zhu, Mingda; Hu, Zongyang

2016-06-07

A nitride-based field effect transistor (FET) comprises a compositionally graded and polarization induced doped p-layer underlying at least one gate contact and a compositionally graded and doped n-channel underlying a source contact. The n-channel is converted from the p-layer to the n-channel by ion implantation, a buffer underlies the doped p-layer and the n-channel, and a drain underlies the buffer.

Investigation of a Training Shoe as a Supplemental Conditioning Device

ERIC Educational Resources Information Center

McKinney, Donald; And Others

1975-01-01

This study investigated the use of the "LEGG" Shoe as a supplemental conditioner for leg strength, flexibility, and sprint speed of college varisity football players. The investigation concluded that a program using the "LEGG" Shoe was significantly superior to the regular conditioning program. (RC)

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.

Differences in Physical Capacity Between Junior and Senior Australian Footballers.

PubMed

Kelly, Stephen J; Watsford, Mark L; Austin, Damien J; Spurrs, Rob W; Pine, Matthew J; Rennie, Michael J

2017-11-01

Kelly, SJ, Watsford, ML, Austin, DJ, Spurrs, RW, Pine, MJ, and Rennie, MJ. Differences in physical capacity between junior and senior Australian footballers. J Strength Cond Res 31(11): 3059-3066, 2017-The purpose of this study was to profile and compare anthropometric and physical capacities within elite junior and senior Australian football (AF) players of various chronological ages and stages of athletic development. Seventy-nine players, including junior and senior AF players from one professional club, were profiled using 11 assessments. Junior players were divided into 2 groups based on chronological age (under 16 and 18 years) and senior players according to years since drafted to a professional AF team (1-2 years, 3-7 years, and 8+ years). Parametric data were assessed using a 1-way analysis of variance (ANOVA), whereas nonparametric data were assessed using a Kruskal-Wallis ANOVA. The magnitude difference between players was measured using the Hopkins' effect size (ES). Significant differences were evident between under-16 players and all senior player groups for anthropometric (p = 0.001-0.019/ES = 1.25-2.13), absolute strength (p = 0.001-0.01/ES = 1.82-4.46), and relative strength (p = 0.001-0.027/ES = 0.84-3.55). The under-18 players displayed significantly lower absolute strength (p = 0.001-0.012/ES = 1.82-3.79) and relative strength (p = 0.001-0.027/ES = 0.85-4.00) compared with the 3-7 and 8+ players. Significant differences were evident between the under-16 players and senior player groups for explosive jumping and throwing tests (p = 0.001-0.017/ES = 1.03-2.99). Minimal differences were evident between all player groups for running assessments; however, the under-16 players were significantly slower compared with the 8+ players for the 3-km time trial (p < 0.02/ES = 1.31), whereas both junior player groups covered significantly less distance during the Yo-Yo IR2 (p < 0.02/ES = 1.19 and 1.60). Results of this study display a significant deficit in strength between junior and senior AF players.

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 discriminating color features which define the coordinates of each pixel in an 'hybrid color space.' Thanks to this hybrid color representation, each pixel can be assigned to one of the two classes by a minimum distance classification.

Paper-Based Textbooks with Audio Support for Print-Disabled Students.

PubMed

Fujiyoshi, Akio; Ohsawa, Akiko; Takaira, Takuya; Tani, Yoshiaki; Fujiyoshi, Mamoru; Ota, Yuko

2015-01-01

Utilizing invisible 2-dimensional codes and digital audio players with a 2-dimensional code scanner, we developed paper-based textbooks with audio support for students with print disabilities, called "multimodal textbooks." Multimodal textbooks can be read with the combination of the two modes: "reading printed text" and "listening to the speech of the text from a digital audio player with a 2-dimensional code scanner." Since multimodal textbooks look the same as regular textbooks and the price of a digital audio player is reasonable (about 30 euro), we think multimodal textbooks are suitable for students with print disabilities in ordinary classrooms.

Increasing motivation in robot-aided arm rehabilitation with competitive and cooperative gameplay

PubMed Central

2014-01-01

Background Several strategies have been proposed to improve patient motivation and exercise intensity during robot-aided stroke rehabilitation. One relatively unexplored possibility is two-player gameplay, allowing subjects to compete or cooperate with each other to achieve a common goal. In order to explore the potential of such games, we designed a two-player game played using two ARMin arm rehabilitation robots. Methods The game was an air-hockey task displayed on a computer monitor and controlled using shoulder movements in the ARMin robot. Three game modes were tested: single-player (competing against computer), competitive (competing against human), and cooperative (cooperating with human against computer). All modes were played by 30 unimpaired subjects and 8 impaired chronic stroke subjects. The subjects filled out the Intrinsic Motivation Inventory questionnaire after each game mode, as well as a final questionnaire about game preferences and their personality. Results Nearly all unimpaired subjects preferred playing the two-player game modes to the single-player one, as they enjoyed talking and interacting with another person. However, there were two distinct player groups: one liked the competitive mode but not the cooperative mode while the other liked the cooperative but not the competitive mode. Unimpaired subjects who liked the competitive mode also put significantly more effort into it than into the other modes. Results from impaired subjects were similar, with even impaired subjects over 60 years old enjoying competitive gameplay. The subjects’ personalities roughly predicted which mode they would prefer, which was especially evident in a poorly-matched impaired pair that preferred the single-player mode. Conclusions Results indicate great potential for two-player rehabilitation games, in the form of greater enjoyment as well as potentially more intensive exercise compared to single-player games. However, the right game type needs to be chosen for each subject depending on skill and personality, along with selecting an appropriate co-player. Further studies with patients that are currently enrolled in rehabilitation programs are recommended, and the subjective measures used in our study should be augmented with objective measures such as electromyography. PMID:24739255

Increasing motivation in robot-aided arm rehabilitation with competitive and cooperative gameplay.

PubMed

Novak, Domen; Nagle, Aniket; Keller, Urs; Riener, Robert

2014-04-16

Several strategies have been proposed to improve patient motivation and exercise intensity during robot-aided stroke rehabilitation. One relatively unexplored possibility is two-player gameplay, allowing subjects to compete or cooperate with each other to achieve a common goal. In order to explore the potential of such games, we designed a two-player game played using two ARMin arm rehabilitation robots. The game was an air-hockey task displayed on a computer monitor and controlled using shoulder movements in the ARMin robot. Three game modes were tested: single-player (competing against computer), competitive (competing against human), and cooperative (cooperating with human against computer). All modes were played by 30 unimpaired subjects and 8 impaired chronic stroke subjects. The subjects filled out the Intrinsic Motivation Inventory questionnaire after each game mode, as well as a final questionnaire about game preferences and their personality. Nearly all unimpaired subjects preferred playing the two-player game modes to the single-player one, as they enjoyed talking and interacting with another person. However, there were two distinct player groups: one liked the competitive mode but not the cooperative mode while the other liked the cooperative but not the competitive mode. Unimpaired subjects who liked the competitive mode also put significantly more effort into it than into the other modes. Results from impaired subjects were similar, with even impaired subjects over 60 years old enjoying competitive gameplay. The subjects' personalities roughly predicted which mode they would prefer, which was especially evident in a poorly-matched impaired pair that preferred the single-player mode. Results indicate great potential for two-player rehabilitation games, in the form of greater enjoyment as well as potentially more intensive exercise compared to single-player games. However, the right game type needs to be chosen for each subject depending on skill and personality, along with selecting an appropriate co-player. Further studies with patients that are currently enrolled in rehabilitation programs are recommended, and the subjective measures used in our study should be augmented with objective measures such as electromyography.

Gold rush - A swarm dynamics in games

NASA Astrophysics Data System (ADS)

Zelinka, Ivan; Bukacek, Michal

2017-07-01

This paper is focused on swarm intelligence techniques and its practical use in computer games. The aim is to show how a swarm dynamics can be generated by multiplayer game, then recorded, analyzed and eventually controlled. In this paper we also discuss possibility to use swarm intelligence instead of game players. Based on our previous experiments two games, using swarm algorithms are mentioned briefly here. The first one is strategy game StarCraft: Brood War, and TicTacToe in which SOMA algorithm has also take a role of player against human player. Open research reported here has shown potential benefit of swarm computation in the field of strategy games and players strategy based on swarm behavior record and analysis. We propose new game called Gold Rush as an experimental environment for human or artificial swarm behavior and consequent analysis.

The female player does not exist: gender identity relates to differences in player motivations and play styles.

PubMed

Poels, Karolien; De Cock, Nele; Malliet, Steven

2012-11-01

This study addresses the female player of massively multiplayer online (role-playing) games and investigates how gender identity (GI), indicating a person's identification with characteristics that are traditionally defined as masculine or feminine, can be used to explain playing patterns within the female gender group. Results from an online survey (n=466) show that females' player motivations and play styles vary as a function of their GI, indicating that it is a relevant and additional predictor of play behavior and confirming that female play behavior cannot be generalized based on stereotypical male/female conceptions.

Expected Reachability-Time Games

NASA Astrophysics Data System (ADS)

Forejt, Vojtěch; Kwiatkowska, Marta; Norman, Gethin; Trivedi, Ashutosh

In an expected reachability-time game (ERTG) two players, Min and Max, move a token along the transitions of a probabilistic timed automaton, so as to minimise and maximise, respectively, the expected time to reach a target. These games are concurrent since at each step of the game both players choose a timed move (a time delay and action under their control), and the transition of the game is determined by the timed move of the player who proposes the shorter delay. A game is turn-based if at any step of the game, all available actions are under the control of precisely one player. We show that while concurrent ERTGs are not always determined, turn-based ERTGs are positionally determined. Using the boundary region graph abstraction, and a generalisation of Asarin and Maler's simple function, we show that the decision problems related to computing the upper/lower values of concurrent ERTGs, and computing the value of turn-based ERTGs are decidable and their complexity is in NEXPTIME ∩ co-NEXPTIME.

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

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 became 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.

Talent identification and selection in elite youth football: An Australian context.

PubMed

O'Connor, Donna; Larkin, Paul; Mark Williams, A

2016-10-01

We identified the perceptual-cognitive skills and player history variables that differentiate players selected or not selected into an elite youth football (i.e. soccer) programme in Australia. A sample of elite youth male football players (n = 127) completed an adapted participation history questionnaire and video-based assessments of perceptual-cognitive skills. Following data collection, 22 of these players were offered a full-time scholarship for enrolment at an elite player residential programme. Participants selected for the scholarship programme recorded superior performance on the combined perceptual-cognitive skills tests compared to the non-selected group. There were no significant between group differences on the player history variables. Stepwise discriminant function analysis identified four predictor variables that resulted in the best categorization of selected and non-selected players (i.e. recent match-play performance, region, number of other sports participated, combined perceptual-cognitive performance). The effectiveness of the discriminant function is reflected by 93.7% of players being correctly classified, with the four variables accounting for 57.6% of the variance. Our discriminating model for selection may provide a greater understanding of the factors that influence elite youth talent selection and identification.

Neural Correlates of Receiving an Apology and Active Forgiveness: An fMRI Study

PubMed Central

Strang, Sabrina; Utikal, Verena; Fischbacher, Urs; Weber, Bernd; Falk, Armin

2014-01-01

Interpersonal conflicts are a common element of many social relationships. One possible process in rebuilding social relationships is the act of apologizing. Behavioral studies have shown that apologies promote forgiveness. However, the neural bases of receiving an apology and forgiveness are still unknown. Hence, the aim of the present fMRI study was to investigate brain processes involved in receiving an apology and active forgiveness of an ambiguous offense. We asked one group of participants (player A) to make decisions, which were either positive or negative for another group of participants (player B). The intention of player A was ambiguous to player B. In case of a negative impact, participants in the role of player A could send an apology message to participants in the role of player B. Subsequently players B were asked whether they wanted to forgive player A for making a decision with negative consequences. We found that receiving an apology yielded activation in the left inferior frontal gyrus, the left middle temporal gyrus, and left angular gyrus. In line with previous research we found that forgiving judgments activated the right angular gyrus. PMID:24505303

Perceiving patterns of play in dynamic sport tasks: investigating the essential information underlying skilled performance.

PubMed

Willams, A Mark; Hodges, Nicola J; North, Jamie S; Barton, Gabor

2006-01-01

The perceptual-cognitive information used to support pattern-recognition skill in soccer was examined. In experiment 1, skilled players were quicker and more accurate than less-skilled players at recognising familiar and unfamiliar soccer action sequences presented on film. In experiment 2, these action sequences were converted into point-light displays, with superficial display features removed and the positions of players and the relational information between them made more salient. Skilled players were more accurate than less-skilled players in recognising sequences presented in point-light form, implying that each pattern of play can be defined by the unique relations between players. In experiment 3, various offensive and defensive players were occluded for the duration of each trial in an attempt to identify the most important sources of information underpinning successful performance. A decrease in response accuracy was observed under occluded compared with non-occluded conditions and the expertise effect was no longer observed. The relational information between certain key players, team-mates and their defensive counterparts may provide the essential information for effective pattern-recognition skill in soccer. Structural feature analysis, temporal phase relations, and knowledge-based information are effectively integrated to facilitate pattern recognition in dynamic sport tasks.

Monitoring Elite Soccer Players' External Loads Using Real-Time Data.

PubMed

Barrett, Steve

2017-11-01

To assess the validity of measuring locomotor activities and PlayerLoad using real-time (RT) data collection during soccer training. Twenty-nine English soccer players participated. Each player wore the same MEMS device (Micromechanical Electrical Systems; S5, Optimeye; CatapultSports, Melbourne, Australia) during 21 training sessions (N = 331 data sets) in the 2015-16 and 2016-17 seasons. An RT receiver (TRX; Catapultsports, Melbourne, Australia) was used to collect the locomotor activities and PlayerLoad data in RT and compared with the postevent downloaded (PED) data. PlayerLoad and locomotor activities (total distance covered; total high-speed running distance covered, >5.5#x00A0;m/s; total sprinting distance covered, >7 m/s; maximum velocity) were analyzed. Correlations were near perfect for all variables analyzed (r = .98-1.00), with a varied level of noise between RT and PED also (0.3-9.7% coefficient of variation). Locomotor activities and PlayerLoad can use both RT and PED concurrently to quantify a player's physical output during a training session. Caution should be taken with higher-velocity-based locomotor activities during RT compared to PED.

Effects of Combined Resistance Training and Plyometrics on Physical Performance in Young Soccer Players.

PubMed

Franco-Márquez, F; Rodríguez-Rosell, D; González-Suárez, J M; Pareja-Blanco, F; Mora-Custodio, R; Yañez-García, J M; González-Badillo, J J

2015-11-01

This study aimed to determine the effects of combined resistance training and plyometrics on physical performance in under-15 soccer players. One team (n=20) followed a 6-week resistance training program combined with plyometrics plus a soccer training program (STG), whereas another team (n=18) followed only the soccer training (CG). Strength training consisted of full squats with low load (45-60% 1RM) and low-volume (2-3 sets and 4-8 repetitions per set) combined with jumps and sprints twice a week. Sprint time in 10 and 20 m (T10, T20, T10-20), CMJ height, estimated one-repetition maximum (1RMest), average velocity attained against all loads common to pre- and post-tests (AV) and velocity developed against different absolute loads (MPV20, 30, 40 and 50) in full squat were selected as testing variables to evaluate the effects of the training program. STG experienced greater gains (P<0.05) in T20, CMJ, 1RMest, AV and MPV20, 30, 40 and 50 than CG. In addition, STG showed likely greater effects in T10 and T10-20 compared to CG. These results indicate that only 6 weeks of resistance training combined with plyometrics in addition to soccer training produce greater gains in physical performance than typical soccer training alone in young soccer players. © Georg Thieme Verlag KG Stuttgart · New York.

Kentucky's Statewide Early Childhood Professional Development System

ERIC Educational Resources Information Center

Rous, Beth; Grove, Jaime; Townley, Kim

2007-01-01

Public school systems have recently become major players in providing services for children in their early years. In addition, a number of other services are available to young children including child care, Head Start, and Early Head Start programs. The link between program quality and professional development of early care and education…

Chinese Summer Schools Sell Quick Credits

ERIC Educational Resources Information Center

McMurtrie, Beth; Farrar, Lara

2013-01-01

American-style summer programs in China, catering to Chinese-born students, have taken American universities by surprise. They are yet one more player in the complex and often opaque Chinese education industry, an industry in which American colleges are finding themselves increasingly entwined. These programs have become a booming enterprise,…

A comparison of methods to quantify the in-season training load of professional soccer players.

PubMed

Scott, Brendan R; Lockie, Robert G; Knight, Timothy J; Clark, Andrew C; Janse de Jonge, Xanne A K

2013-03-01

To compare various measures of training load (TL) derived from physiological (heart rate [HR]), perceptual (rating of perceived exertion [RPE]), and physical (global positioning system [GPS] and accelerometer) data during in-season field-based training for professional soccer. Fifteen professional male soccer players (age 24.9 ± 5.4 y, body mass 77.6 ± 7.5 kg, height 181.1 ± 6.9 cm) were assessed in-season across 97 individual training sessions. Measures of external TL (total distance [TD], the volume of low-speed activity [LSA; <14.4 km/h], high-speed running [HSR; >14.4 km/h], very high-speed running [VHSR; >19.8 km/h], and player load), HR and session-RPE (sRPE) scores were recorded. Internal TL scores (HR-based and sRPE-based) were calculated, and their relationships with measures of external TL were quantified using Pearson product-moment correlations. Physical measures of TD, LSA volume, and player load provided large, significant (r = .71-.84; P < .01) correlations with the HR-based and sRPE-based methods. Volume of HSR and VHSR provided moderate to large, significant (r = .40-.67; P < .01) correlations with measures of internal TL. While the volume of HSR and VHSR provided significant relationships with internal TL, physical-performance measures of TD, LSA volume, and player load appear to be more acceptable indicators of external TL, due to the greater magnitude of their correlations with measures of internal TL.

Skate blade neck lacerations: a survey and case follow-up.

PubMed

Stuart, Michael J; Link, Andrew A; Smith, Aynsley M; Krause, David A; Sorenson, Matthew C; Larson, Dirk R

2009-11-01

To learn about neck lacerations caused by skate blades in hockey. A retrospective Web-based survey and follow-up of registered USA Hockey players. Three hundred twenty-eight thousand eight hundred twenty-one of 457 038 registered USA Hockey players with a current e-mail address were contacted and invited to participate in the survey. Of 26 589 players (5.8% of all USA registered players) who responded to the survey, 247 were excluded due to incomplete data. Of 26 342 surveys analyzed, 23 199 respondents were men (88%), 3015 women (11.4%), and 128 (0.5%) did not designate gender. An original survey instrument was developed, formatted, and linked to a Mayo Clinic Web site. Neck lacerations from a skate blade, including mechanism, severity, treatment required, and the type of neck protector worn. Of the 26 342 respondents, 11 935 (45.4%) currently wear neck protection and 485 (1.8%) have sustained a neck laceration. When the laceration occurred, 132 of the players (27%) were wearing neck protection. Interviews with 33 injured players established that lacerations were superficial: 20 (61%) required bandaging only, 11 were sutured, and 2 were glued. Based on this survey, the currently available neck laceration protectors do not eliminate the risk of a neck laceration from a skate blade.

The effect of plyometric training on power and kicking distance in female adolescent soccer players.

PubMed

Rubley, Mack D; Haase, Amaris C; Holcomb, William R; Girouard, Tedd J; Tandy, Richard D

2011-01-01

The purpose of this study was to measure the effects of low-frequency, low-impact plyometric training on vertical jump (VJ) and kicking distance in female adolescent soccer players. Sixteen adolescent soccer players were studied (age 13.4 ± 0.5 years) across 14 weeks. The control group (general soccer training only) had 6 subjects, and the plyometric training (general soccer training plus plyometric exercise) group had 10 subjects. All subjects were tested for VJ and kicking distance on 3 occasions: pre-test, 7 weeks, and 14 weeks. Data were analyzed using a 2 (Training) × 3 (Test) analysis of variance (ANOVA) with repeated measures on the factor test. No significant difference in kicking distance was found between groups at pre-test (p = 0.688) or 7 weeks (p = 0.117). The plyometric group had significantly greater kicking distance after 14 weeks (p < 0.001). No significant difference in VJ height was found between groups at pre-test (p = 0.837) or 7 weeks (p = 0.108). The plyometric group had a significantly higher VJ after 14 weeks (p = 0.014). These results provide strength coaches with a safe and effective alternative to high-intensity plyometric training. Based on these findings, to increase lower-body power resulting in increased VJ and kicking distance, strength coaches should implement once-weekly, low-impact plyometric training programs with their adolescent athletes.

Groin Problems in Male Soccer Players Are More Common Than Previously Reported.

PubMed

Harøy, Joar; Clarsen, Ben; Thorborg, Kristian; Hölmich, Per; Bahr, Roald; Andersen, Thor Einar

2017-05-01

The majority of surveillance studies in soccer have used a time-loss injury definition, and many groin problems result from overuse, leading to gradually increasing pain and/or reduced performance without necessarily causing an absence from soccer training or match play. Thus, the magnitude of groin problems in soccer has probably been underestimated in previous studies based on traditional injury surveillance methods. To investigate the prevalence of groin problems among soccer players of both sexes and among male soccer players at different levels of play through a new surveillance method developed to capture acute and overuse problems. Descriptive epidemiology study. We registered groin problems during a 6-week period of match congestion using the Oslo Sports Trauma Research Center Overuse Injury Questionnaire. A total of 240 players from 15 teams across different levels of play and from both sexes were included, and they responded to the weekly questionnaire. We calculated the average weekly prevalence of all groin problems and substantial groin problems. Of the 240 players, 112 male players (59%) and 20 female players (45%) reported at least 1 episode of groin problems. The average weekly prevalence of any groin problem and substantial groin problem for all male players was 29% (range, 23%-32% across different levels) and 10% (7%-13%), respectively. Elite male players had an increased risk of experiencing groin problems (odds ratio: 3.1, 95% CI: 1.5-6.4, P = .03) compared with elite female players. There was no difference in the risk of experiencing groin problems among elite, subelite, and amateur male players. For substantial problems, there was no difference between elite male and elite female players or among levels of play for senior male soccer players. We found a high prevalence of groin problems among male soccer players during a period with match congestion. Time-loss definition as used in previous injury surveillance studies captured only one-third of the male groin problems registered with the new method. Elite male players had 3 times' higher risk of reporting groin problems as compared with elite female players, while playing level did not influence the risk of reporting a groin problem among males.

Physical Performance in Elite Male and Female Team Handball Players.

PubMed

Wagner, Herbert; Fuchs, Patrick; Fusco, Andrea; Fuchs, Philip; Bell, W Jeffrey; Duvillard, Serge P

2018-06-12

Biological differences between men and women are well known; however, literature-addressing knowledge about the influence of sex to specific and general performance in team handball is almost nonexistent. Consequently, the aim of the study was to assess and compare specific and general physical performance in male and female elite team handball players, to determine if the differences are consequential for general compared to specific physical performance characteristics and the relationship between general and specific physical performance. Twelve male and ten female elite team handball players performed a game based performance test, upper- und lower-body strength and power tests, a sprinting test, and an incremental treadmill-running test. Significant differences (P<.05) between male and female players were found for peak oxygen uptake and total running time during the treadmill test, 30m sprinting time, leg extension strength, trunk and shoulder rotation torque, counter movement jump height as well as offense and defense time, ball velocity and jump height in the game based performance test. An interaction (sex × test) was found for time and oxygen uptake and except shoulder rotation torque and ball velocity in females, we found only a low relationship between specific and general physical performance. The results of the study revealed that male players are heavier, taller, faster, stronger, jump higher and have a better aerobic performance. However, female players performed relatively better in the team handball specific tests compared to the general tests. Our findings also suggest that female players should focus more on strength training.

The art of war: beyond memory-one strategies in population games.

PubMed

Lee, Christopher; Harper, Marc; Fryer, Dashiell

2015-01-01

We show that the history of play in a population game contains exploitable information that can be successfully used by sophisticated strategies to defeat memory-one opponents, including zero determinant strategies. The history allows a player to label opponents by their strategies, enabling a player to determine the population distribution and to act differentially based on the opponent's strategy in each pairwise interaction. For the Prisoner's Dilemma, these advantages lead to the natural formation of cooperative coalitions among similarly behaving players and eventually to unilateral defection against opposing player types. We show analytically and empirically that optimal play in population games depends strongly on the population distribution. For example, the optimal strategy for a minority player type against a resident TFT population is ALLC, while for a majority player type the optimal strategy versus TFT players is ALLD. Such behaviors are not accessible to memory-one strategies. Drawing inspiration from Sun Tzu's the Art of War, we implemented a non-memory-one strategy for population games based on techniques from machine learning and statistical inference that can exploit the history of play in this manner. Via simulation we find that this strategy is essentially uninvadable and can successfully invade (significantly more likely than a neutral mutant) essentially all known memory-one strategies for the Prisoner's Dilemma, including ALLC (always cooperate), ALLD (always defect), tit-for-tat (TFT), win-stay-lose-shift (WSLS), and zero determinant (ZD) strategies, including extortionate and generous strategies.

ULTRASONOGRAPHIC ASSESSMENT OF NECK MUSCULAR SIZE AND RANGE OF MOTION IN RUGBY PLAYERS

PubMed Central

Calistri, Josselin; Papadopoulou, Virginie; Theunissen, Sigrid; Dugardeyn, Christian; Balestra, Costantino

2018-01-01

Background World Rugby Union laws are constantly evolving towards stringent injury-prevention, particularly for contested scrums, since front row players are most at risk of cervical spine injuries. Recently, some countries have also introduced tailored training programs and minimum performance requirements for playing in the front row. Nevertheless, these approaches lack an objective assessment of each cervical muscle that would provide protective support. Objective Since front row players are the most at risk for cervical spine injuries due to the specific type of contact during scrums, the purpose of this study was to ascertain whether significant differences exist in neck muscle size and range of motion between front row players and players of other positions, across playing categories. Study Design Cross-sectional controlled laboratory study Methods 129 sub-elite male subjects from various first-team squads of Belgian Rugby clubs were recruited. Subjects were grouped according to age: Junior (J) < 19 years old, Senior (S) 19 to 35 years old and Veteran (V) > 35 years old; as well as playing position: Front row players (J = 10, S = 12, V = 11 subjects), (Rest of the) pack (J = 12, S = 12, V = 10), backs (J = 10, S = 11, V = 11). An age-matched control group of non-rugby players was also recruited (J = 10, S = 10, V = 10). For each subject, the total neck circumference (NC) and the cervical range of motion (CROM) were measured. In addition, the thickness of the trapezius (T), splenius capitis (SCa), semispinalis capitis (SCb), semispinalis cervicis (SPC), sternocleidomastoid muscles (SCOM), and the total thickness of all four structures (TT), were measured using ultrasonography. Results In each age category, compared to controls, rugby players were found to have decreased CROM, an increase in neck circumference (NC), and increased total thickness (TT), trapezius (T), semispinalis capitis (SCb) and sternocleidomastoid muscles (SCOM) sizes. For junior players, the thickness of the semispinalis cervicis (SPC) was also increased compared to controls. The CROM was decreased in front row players compared to pack and back players for all age categories; Front row seniors also showed an increase in trapezius (T), splenius capitis (SCa), semispinalis capitis (SCb) and total thickness (TT), compared to back players. Conclusion In regard of the differences in cervical values found between player positions, the implementation of both range of motion and echography muscle thickness assessments could serve to create an additional measurement for all front row players, that could complement current pre-participation screening used by rugby federations by objectively monitoring muscular size and motion amplitude around the cervical spine. PMID:29484239

Annual Report of the Chief, National Guard Bureau for the Fiscal Year 1971

DTIC Science & Technology

1971-06-30

caaBKinan nicnaKs «a as $mm KI K oriiiims m nriiws liflSIW KI 00 msoHii imsM •» o» 13 J Army CHAMPS Team Handball In January 1971 the Army CHAMPS...the sport of team handball in the United States which would provide a talent base from which to draw players for the U.S. Olympic Team. These... handball . Domestic Action National Guard Domestic Action programs, designed to alleviate social problems within communities throughout the United States

[Comparison of somatotype differences of soccer and handball players based on the methods of German and Anglo-American schools of constitutional biology].

PubMed

Raschka, Christoph; Wolthausen, Christina

2007-09-01

39 soccer players of the third division as well as 22 handball players of the second division and 17 handball fourth division players (average age 24 years) were examined kinanthropometrically. The sports anthropological evaluations were made according to the methods of Parnell (1958), Heath & Carter (1967), Conrad (1963), Knussmann (1961a, 1961b) as well as Tittel & Wutscherk (1972). Regarding the proportionality, proportion figures and phantom stratagem were used. In the typology of Conrad (1963) above all the high hyperplasia values of the handball players stand out. According to the typognosis of Knussmann (1961a, 1961b) the handball and soccer players are to be classified as leptomorph. The tendency to the macrosomia pole is to be recognized for the handball players. In the somatochart of Parnell (1958) soccer and handball players are placed in the mesomorph ectomorph sixth. The group differences are highly significant for the endomorphy. In the somatogramm of Heath & Carter (1967) both ballplayer collectives are settled in the ectomorph mesomorph area. The group differences are here for the endomorphy and mesomorphy highly significant, for the ectomorphy significant. The proportional fat portion (calipermetry) is high-significantly lower for the soccer players with 6.6 +/- 1.6% than for the handball players (8.4 +/- 2.5%). All height and longitudinal dimensions as well as the circumferences with exception of the thigh girth were for the larger handball players (body height: 189.1 +/- 7.9 cm) very to highly significantly higher than for the smaller soccer players (body height: 178.6 +/- 5.8 cm), whereby no important proportional differences were registered.

Reinventing the Wheel: One Program's Approach to Redesign of Didactic Courses.

PubMed

Hudak, Nicholas M; Scott, Victoria; Spear, Sherrie B; Hills, Karen J

2015-12-01

Curriculum and course redesign are expected and intentional efforts in health professions education. For physician assistant (PA) education, ongoing program self-assessment is a required accreditation standard and may guide deliberate changes within curriculum. The purpose of this article is to describe one PA program’s approach to the redesign of 4 courses into 3 courses that span the entire didactic phase. Significant lessons learned include the importance of planning ahead, identifying key players, documenting the process as part of ongoing self-assessment, competency mapping, and being prepared to make real-time modifications and changes based on course evaluations and faculty feedback. Our approach and guiding principles to the successful redesign of the didactic courses may provide both established and new PA educational programs with useful methods to apply in their own unique curricula.

Cooperation in memory-based prisoner's dilemma game on interdependent networks

NASA Astrophysics Data System (ADS)

Luo, Chao; Zhang, Xiaolin; Liu, Hong; Shao, Rui

2016-05-01

Memory or so-called experience normally plays the important role to guide the human behaviors in real world, that is essential for rational decisions made by individuals. Hence, when the evolutionary behaviors of players with bounded rationality are investigated, it is reasonable to make an assumption that players in system are with limited memory. Besides, in order to unravel the intricate variability of complex systems in real world and make a highly integrative understanding of their dynamics, in recent years, interdependent networks as a comprehensive network structure have obtained more attention in this community. In this article, the evolution of cooperation in memory-based prisoner's dilemma game (PDG) on interdependent networks composed by two coupled square lattices is studied. Herein, all or part of players are endowed with finite memory ability, and we focus on the mutual influence of memory effect and interdependent network reciprocity on cooperation of spatial PDG. We show that the density of cooperation can be significantly promoted within an optimal region of memory length and interdependent strength. Furthermore, distinguished by whether having memory ability/external links or not, each kind of players on networks would have distinct evolutionary behaviors. Our work could be helpful to understand the emergence and maintenance of cooperation under the evolution of memory-based players on interdependent networks.

Evolutionary games in the multiverse

PubMed Central

Gokhale, Chaitanya S.; Traulsen, Arne

2010-01-01

Evolutionary game dynamics of two players with two strategies has been studied in great detail. These games have been used to model many biologically relevant scenarios, ranging from social dilemmas in mammals to microbial diversity. Some of these games may, in fact, take place between a number of individuals and not just between two. Here we address one-shot games with multiple players. As long as we have only two strategies, many results from two-player games can be generalized to multiple players. For games with multiple players and more than two strategies, we show that statements derived for pairwise interactions no longer hold. For two-player games with any number of strategies there can be at most one isolated internal equilibrium. For any number of players with any number of strategies , there can be at most isolated internal equilibria. Multiplayer games show a great dynamical complexity that cannot be captured based on pairwise interactions. Our results hold for any game and can easily be applied to specific cases, such as public goods games or multiplayer stag hunts. PMID:20212124

The neural mechanisms of learning from competitors.

PubMed

Howard-Jones, Paul A; Bogacz, Rafal; Yoo, Jee H; Leonards, Ute; Demetriou, Skevi

2010-11-01

Learning from competitors poses a challenge for existing theories of reward-based learning, which assume that rewarded actions are more likely to be executed in the future. Such a learning mechanism would disadvantage a player in a competitive situation because, since the competitor's loss is the player's gain, reward might become associated with an action the player should themselves avoid. Using fMRI, we investigated the neural activity of humans competing with a computer in a foraging task. We observed neural activity that represented the variables required for learning from competitors: the actions of the competitor (in the player's motor and premotor cortex) and the reward prediction error arising from the competitor's feedback. In particular, regions positively correlated with the unexpected loss of the competitor (which was beneficial to the player) included the striatum and those regions previously implicated in response inhibition. Our results suggest that learning in such contexts may involve the competitor's unexpected losses activating regions of the player's brain that subserve response inhibition, as the player learns to avoid the actions that produced them. Copyright 2010 Elsevier Inc. All rights reserved.

Internal- and External-Rotation Peak Toque in Little League Baseball Players With Subacromial Impingement Syndrome: Improved by Closed Kinetic Chain Shoulder Training.

PubMed

Lee, Dong-Rour; Kim, Laurentius Jongsoon

2016-08-01

Many studies have explored closed kinetic chain (CKC) shoulder exercises (SEs) with a sling because they are safer and more effective than open-chain exercises, especially in early stages of treatment. However, the application of CKC SE in youth baseball players has rarely been attempted, although teenage baseball players also experience shoulder pain. To investigate the effects of CKC SE on the peak torque of shoulder internal rotation (IR) and external rotation (ER) in youth baseball players. Single-group pretest, posttest. Biomechanics laboratory. 23 Little League Baseball players with subacromial impingement syndrome. The CKC SE with a sling was CKC shoulder-flexion exercise, extension exercise, IR exercise, and ER exercise. This exercise regimen was conducted 2 or 3 times/wk for 8 wk. The peak torque of shoulder IR and ER was measured using an isokinetic dynamometer. Concentric shoulder rotation was performed, with 5 repetitions at an angular velocity of 60°/s and 15 at 180°/s. The IR and ER peak torque significantly increased at each angular velocity after the exercise program. In particular, the increase in IR and ER peak torque values was statistically significant at an angular velocity of 180°/s. CKC SE was effective in increasing shoulder IR and ER strength, demonstrating its potential benefits in the prevention and treatment of shoulder injury. In addition, increased IR peak torque appears to improve throwing velocity in baseball players.

Comprehensive profile of hip, knee and ankle ranges of motion in professional football players.

PubMed

López-Valenciano, Alejandro; Ayala, Francisco; Vera-García, Francisco J; de Ste Croix, Mark; Hernández-Sánchez, Sergio; Ruiz-Pérez, Iñaki; Cejudo, Antonio; Santonja, Fernando

2017-10-31

Limited ranges of motion (ROM) have been considered as a primary risk factor for some football injuries, but only a few studies have analysed differences in lower extremity joints. The main purposes were (a) to describe the lower extremity ROM profile in professional football players; and (b) to examine differences between goalkeepers and outfield players. 82 professional male football players from 4 teams were measured in the 2013 pre-season. Measures of passive hip (flexion with knee flexed [PHFKF] and extended [PHFKE], extension [PHE], abduction [PHA], external [PHER] and internal [PHIR] rotation), knee (flexion [PKF]) and ankle (dorsiflexion with knee flexed [ADFKF] and extended [ADFKE]) ROMs were taken. Magnitude-based inferences exploring differences between player position and limb were made. 46% of all participants showed restricted PHFKE and/or around 30% showed restricted ADFKF ROM values. Contrarily, most players reported normal PHFKF, PHE, PHIR and PHER as well as PKF ROM scores with percentage values close to 100%. Bilateral meaningful differences for PHA, PHIR and PHER were found in approximately 30% of outfield players and goalkeepers. Statistical analysis found trivial differences between players for PHFKE, PHE, PHIR, PHER, ADFKE and ADFKF. However, moderate differences between players were found for PHFKF, PHA and PKF, with goalkeepers demonstrating higher values than outfield players. The findings of this study reinforce the necessity of prescribing exercises aimed at improving PHFKE and ADFKF ROM within everyday football training routines. In addition, as some bilateral deficits were observed, unilateral training should be considered where appropriate.

Jump Landing Characteristics Predict Lower Extremity Injuries in Indoor Team Sports.

PubMed

van der Does, H T D; Brink, M S; Benjaminse, A; Visscher, C; Lemmink, K A P M

2016-03-01

The aim of this study is to investigate the predictive value of landing stability and technique to gain insight into risk factors for ankle and knee injuries in indoor team sport players. Seventy-five male and female basketball, volleyball or korfball players were screened by measuring landing stability after a single-leg jump landing and landing technique during a repeated counter movement jump by detailed 3-dimensional kinematics and kinetics. During the season 11 acute ankle injuries were reported along with 6 acute and 7 overuse knee injuries by the teams' physical therapist. Logistic regression analysis showed less landing stability in the forward and diagonal jump direction (OR 1.01-1.10, p≤0.05) in players who sustained an acute ankle injury. Furthermore landing technique with a greater ankle dorsiflexion moment increased the risk for acute ankle injury (OR 2.16, p≤0.05). A smaller knee flexion moment and greater vertical ground reaction force increased the risk of an overuse knee injury (OR 0.29 and 1.13 respectively, p≤0.05). Less one-legged landing stability and suboptimal landing technique were shown in players sustaining an acute ankle and overuse knee injury compared to healthy players. Determining both landing stability and technique may further guide injury prevention programs. © Georg Thieme Verlag KG Stuttgart · New York.

Player Preferences and Social Harm: An Analysis of the Relationships between Player Characteristics, Gambling Modes, and Problem Gambling

ERIC Educational Resources Information Center

Young, Martin; Stevens, Matthew

2009-01-01

To explore the structure of gambling participation and its association with problem gambling, we draw upon Caillois's distinction between games based on competition (i.e. "agon") and those based on chance (i.e. "alea"). The idea that "alea" and "agon" are socially patterned and associated with differing…

Receiving Video-Based Feedback in Elite Ice-Hockey: A Player's Perspective

ERIC Educational Resources Information Center

Nelson, Lee J.; Potrac, Paul; Groom, Ryan

2014-01-01

The aim of this paper was to provide some rich insights into how an elite ice-hockey player responded to his coaches' pedagogical delivery of video-based feedback sessions. Data for this study were gathered through a series of in-depth, semi-structured interviews and a reflective log relating to those interviews. The interviews were transcribed…

Design of an online EEG based neurofeedback game for enhancing attention and memory.

PubMed

Thomas, Kavitha P; Vinod, A P; Guan, Cuntai

2013-01-01

Brain-Computer Interface (BCI) is an alternative communication and control channel between brain and computer which finds applications in neuroprosthetics, brain wave controlled computer games etc. This paper proposes an Electroencephalogram (EEG) based neurofeedback computer game that allows the player to control the game with the help of attention based brain signals. The proposed game protocol requires the player to memorize a set of numbers in a matrix, and to correctly fill the matrix using his attention. The attention level of the player is quantified using sample entropy features of EEG. The statistically significant performance improvement of five healthy subjects after playing a number of game sessions demonstrates the effectiveness of the proposed game in enhancing their concentration and memory skills.

The Effect of a History-Fitness Updating Rule on Evolutionary Games

NASA Astrophysics Data System (ADS)

Du, Wen-Bo; Cao, Xian-Bin; Liu, Run-Ran; Jia, Chun-Xiao

In this paper, we introduce a history-fitness-based updating rule into the evolutionary prisoner's dilemma game (PDG) on square lattices, and study how it works on the evolution of cooperation level. Under this updating rule, the player i will firstly select player j from its direct neighbors at random and then compare their fitness which is determined by the current payoff and history fitness. If player i's fitness is larger than that of j, player i will be more likely to keep its own strategy. Numerical results show that the cooperation level is remarkably promoted by the history-fitness-based updating rule. Moreover, there exists a moderate mixing proportion of current payoff and history fitness that can induce the optimal fitness, where the highest cooperation level is obtained. Our work may shed some new light on the ubiquitous cooperative behaviors in nature and society induced by the history factor.

Asymmetric Evolutionary Games.

PubMed

McAvoy, Alex; Hauert, Christoph

2015-08-01

Evolutionary game theory is a powerful framework for studying evolution in populations of interacting individuals. A common assumption in evolutionary game theory is that interactions are symmetric, which means that the players are distinguished by only their strategies. In nature, however, the microscopic interactions between players are nearly always asymmetric due to environmental effects, differing baseline characteristics, and other possible sources of heterogeneity. To model these phenomena, we introduce into evolutionary game theory two broad classes of asymmetric interactions: ecological and genotypic. Ecological asymmetry results from variation in the environments of the players, while genotypic asymmetry is a consequence of the players having differing baseline genotypes. We develop a theory of these forms of asymmetry for games in structured populations and use the classical social dilemmas, the Prisoner's Dilemma and the Snowdrift Game, for illustrations. Interestingly, asymmetric games reveal essential differences between models of genetic evolution based on reproduction and models of cultural evolution based on imitation that are not apparent in symmetric games.

Injuries and medical issues in softball.

PubMed

Briskin, Susannah M

2012-01-01

Softball is enjoyed by millions of female and male athletes of all ages and competitive levels. Windmill pitchers are at risk for developing overuse injuries in the throwing arm. Improper mechanics and lack of pitch counts may increase the risk for developing a pitching-related injury. Softball-related overuse injuries include proximal biceps tendinitis, upper extremity stress fractures, and ulnar neuritis. Acute injuries commonly occur in the lower extremity and include both fractures and ligamentous injuries. Sliding injuries account for a significant number of these lower extremity injuries. The addition of breakaway bases and mandatory use of protective headgear by defensive players may decrease acute injuries commonly seen in softball. Off-season programs should stress proper throwing and sliding mechanics, core conditioning, and a lower extremity neuromuscular education program.

A Critical Interpersonal Distance Switches between Two Coordination Modes in Kendo Matches

PubMed Central

Okumura, Motoki; Kijima, Akifumi; Kadota, Koji; Yokoyama, Keiko; Suzuki, Hiroo; Yamamoto, Yuji

2012-01-01

In many competitive sports, players need to quickly and continuously execute movements that co-adapt to various movements executed by their opponents and physical objects. In a martial art such as kendo, players must be able to skillfully change interpersonal distance in order to win. However, very little information about the task and expertise properties of the maneuvers affecting interpersonal distance is available. This study investigated behavioral dynamics underlying opponent tasks by analyzing changes in interpersonal distance made by expert players in kendo matches. Analysis of preferred interpersonal distances indicated that players tended to step toward and away from their opponents based on two distances. The most preferred distance enabled the players to execute both striking and defensive movements immediately. The relative phase analysis of the velocities at which players executed steps toward and away revealed that players developed anti-phase synchronizations at near distances to maintain safe distances from their opponents. Alternatively, players shifted to in-phase synchronization to approach their opponents from far distances. This abrupt phase-transition phenomenon constitutes a characteristic bifurcation dynamics that regularly and instantaneously occurs between in- and anti-phase synchronizations at a critical interpersonal distance. These dynamics are profoundly affected by the task constraints of kendo and the physical constraints of the players. Thus, the current study identifies the clear behavioral dynamics that emerge in a sport setting. PMID:23284799

Epidemiology of injuries in men's lacrosse: injury prevention implications for competition level, type of play, and player position.

PubMed

Barber Foss, Kim D; Le Cara, Ed; McCambridge, Teri; Hinton, Richard; Kushner, Adam; Myer, Gregory D

2017-09-01

The growth in participation in men's lacrosse has increased the likelihood of sport-specific injuries, yet there continues to be a need for specific epidemiological data concerning lacrosse injuries. The purpose of this literature review is to aggregate available published data on injuries that occur in the sport of men's lacrosse at the youth, high school, collegiate, and professional levels. A comprehensive literature search was performed in PubMed, High Wire Press, SPORTDiscus, Google Scholar, and Ovid, using the keywords Lacrosse Injuries, Epidemiology Lacrosse Injuries, Lacrosse Injury, Lacrosse AND Injury and limited to 1990-2016. All bibliographies were cross-referenced to identify any additional publications. Sources were categorized based on data provided and were aggregated into groups based on reported overall injury rates, rates by setting (competition vs. practice), nature of injury, location, type, severity, and player position. The game and practice injury rates in college are greater than the rates in high school, similarly rates greater for high school players than in youth leagues. Rates of injury varied from 0.095-12.98 per 1000 athlete exposures. Game injury rates were higher across all studies. Injuries in men's lacrosse occur most often from player-to-player contact, which result in immediate injuries, such as concussions, contusions, and lacerations. Overall concussion incidence was reported to range from 0.11-0.84 per 1000 AE. The most common types of injuries were sprain, strain, concussion, and contusions and the most common area of injury was hand (23%), with a significant proportion of these (59.4%) being to the thumb. Limited evidence of different injuries among the player positions suggests there might be a pattern that midfield players had the most injuries, followed by offensive players and then defensive players. The potential for sports-related injury is of relative concern; especially considering rising participation and total number of injuries. Further development and proper enforcement of safety rules on player contact and protective equipment are recommended to decrease the rate of lacrosse-related injury. Additional longitudinal research is needed to better classify and to ultimately predict lacrosse injury factors and mechanisms across all levels of play.

Application of game theory in decision making strategy: Does gas fuel industry need to kill oil based fuel industry?

NASA Astrophysics Data System (ADS)

Azmi, Abdul Luky Shofi'ul; Prabandari, Dyah Lusiana; Hakim, Muhammad Lintang Islami

2017-03-01

Even though conversion of oil based fuel (Bahan Bakar Minyak) into gas fuel (Bahan Bakar Gas) for transportation (both land and sea) is one of the priority programs of the government of Indonesia, rules that have been established merely basic rules of gas fuel usage license for transportation, without discussing position of gas fuel related to oil based fuel in detail. This paper focus on possible strategic behavior of the key players in the oil-gas fuel conversion game, who will be impacted by the position of gas fuel as complement or substitution of oil based fuel. These players include industry of oil based fuel, industry of gas fuel, and the government. Modeling is made based on two different conditions: government plays a passive role and government plays an active role in legislating additional rules that may benefit industry of gas fuel. Results obtained under a passive government is that industry of oil based fuel need to accommodate the presence of industry of gas fuel, and industry of gas fuel does not kill/ eliminate the oil based fuel, or gas fuel serves as a complement. While in an active government, the industry of oil based fuel need to increase its negotiation spending in the first phase so that the additional rule that benefitting industry of gas fuel would not be legislated, while industry of gas fuel chooses to indifferent; however, in the last stage, gas fuel turned to be competitive or choose its role to be substitution.

Relationship between performance variables and baseball ability in youth baseball players.

PubMed

Nakata, Hiroki; Nagami, Tomoyuki; Higuchi, Takatoshi; Sakamoto, Kiwako; Kanosue, Kazuyuki

2013-10-01

The present study investigated the relationship of performance variables and anthropometric measurements on baseball ability in 164 youth baseball players (age: 6.4-15.7 years). To evaluate their baseball performance, ball speeds in pitching and batting were recorded and kinetic energies of the pitched and hit balls were calculated. To record anthropometric and physical fitness characteristics, height and weight were measured and a battery of physical fitness tests covering standing long jump, side steps, sit-ups, 10-m sprint, trunk flexion, back strength, and grip strengths of both hands were conducted. The results of a multiple regression analysis revealed several significant predictors: age, body mass index (BMI), standing long jump, 10-m sprint, and grip strength for pitched ball kinetic energy and age, BMI, standing long jump, and back strength for hit ball kinetic energy. This study provides scientific evidence that relates certain specific physical performance tests and body characteristics with high achievement in the actual performance of pitching and batting. Youth players, their parents, coaches, and trainers would benefit by addressing these characteristics when planning training programs to improve the baseball performance of youth players.

Predictors of return rate discrimination in slot machine play.

PubMed

Coates, Ewan; Blaszczynski, Alex

2014-09-01

The purpose of this study was to investigate the extent to which accurate estimates of payback percentages and volatility combined with prior learning, enabled players to successfully discriminate between multi-line/multi-credit slot machines that provided differing rates of reinforcement. The aim was to determine if the capacity to discriminate structural characteristics of gaming machines influenced player choices in selecting 'favourite' slot machines. Slot machine gambling history, gambling beliefs and knowledge, impulsivity, illusions of control, and problem solving style were assessed in a sample of 48 first year undergraduate psychology students. Participants were subsequently exposed to a choice paradigm where they could freely select to play either of two concurrently presented PC-simulated slot machines programmed to randomly differ in expected player return rates (payback percentage) and win frequency (volatility). Results suggest that prior learning and cognitions (particularly gambler's fallacy) but not payback, were major contributors to the ability of a player to discriminate volatility between slot machines. Participants displayed a general tendency to discriminate payback, but counter-intuitively placed more bets on the slot machine with lower payback percentage rates.

Influence of viewing professional ice hockey on youth hockey injuries.

PubMed

Keays, G; Pless, B

2013-03-01

Most televised National Hockey League (NHL) games include violent body checks, illegal hits and fights. We postulated that minor league players imitated these behaviours and that not seeing these games would reduce the rate of injuries among younger hockey players. Using a quasi-experimental design, we compared 7 years of televised NHL matches (2002-2009) with the year of the NHL lock-out (2004/2005). Data from the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) were used to identify the injuries and to ascertain whether they were due to intentional contact and illegal acts including fights. We found no significant differences in the proportions of all injuries and those involving intentional contact, violations or illegal acts among male minor league hockey players during the year when professional players were locked out and the years before and after the lock-out. We concluded that not seeing televised NHL violence may not reduce injuries, although a possible effect may have been obscured because there was a striking increase in attendance at equally violent minor league games during the lock-out.

Effects of Unloaded vs. Loaded Plyometrics on Speed and Power Performance of Elite Young Soccer Players.

PubMed

Kobal, Ronaldo; Pereira, Lucas A; Zanetti, Vinicius; Ramirez-Campillo, Rodrigo; Loturco, Irineu

2017-01-01

The purpose of this study was to investigate the effects of loaded and unloaded plyometric training strategies on speed and power performance of elite young soccer players. Twenty-three under-17 male soccer players (age: 15.9 ± 1.2 years, height: 178.3 ± 8.1 cm, body-mass (BM): 68.1 ± 9.3 kg) from the same club took part in this study. The athletes were pair-matched in two training groups: loaded vertical and horizontal jumps using an haltere type handheld with a load of 8% of the athletes' body mass (LJ; n = 12) and unloaded vertical and horizontal plyometrics (UJ; n = 11). Sprinting speeds at 5-, 10-, and 20-m, mean propulsive power (MPP) relative to the players' BM in the jump squat exercise, and performance in the squat jump (SJ) and countermovement jump (CMJ) were assessed pre- and post-training period. During the experimental period, soccer players performed 12 plyometric training sessions across a 6-week preseason period. Magnitude based inferences and standardized differences were used for statistical analysis. A very likely increase in the vertical jumps was observed for the LJ group (99/01/00 and 98/02/00 for SJ and CMJ, respectively). In the UJ group a likely increase was observed for both vertical jumps (83/16/01 and 90/10/00, for SJ and CMJ, respectively). An almost certainly decrease in the sprinting velocities along the 20-m course were found in the LJ group (00/00/100 for all split distances tested). Meanwhile, in the UJ likely to very likely decreases were observed for all sprinting velocities tested (03/18/79, 01/13/86, and 00/04/96, for velocities in 5-, 10-, and 20-m, respectively). No meaningful differences were observed for the MPP in either training group (11/85/04 and 37/55/08 for LJ and UJ, respectively). In summary, under-17 professional soccer players increased jumping ability after a 6-week preseason training program, using loaded or unloaded jumps. Despite these positive adaptations, both plyometric strategies failed to produce worthwhile improvements in maximal speed and power performances, which is possible related to the interference of concurrent training effects. New training strategies should be developed to ensure adequate balance between power and endurance loads throughout short (and high-volume) soccer preseasons.

Prevalence and Clinical Characteristics of Osteochondritis Dissecans of the Humeral Capitellum Among Adolescent Baseball Players.

PubMed

Kida, Yoshikazu; Morihara, Toru; Kotoura, Yoshihiro; Hojo, Tatsuya; Tachiiri, Hisakazu; Sukenari, Tsuyoshi; Iwata, Yoshio; Furukawa, Ryuhei; Oda, Ryo; Arai, Yuji; Fujiwara, Hiroyoshi; Kubo, Toshikazu

2014-08-01

The prevalence and clinical characteristics of osteochondritis dissecans (OCD) of the humeral capitellum among adolescent baseball players are unknown. To determine the OCD prevalence in adolescent competitive baseball players and to investigate the clinical characteristics of these patients. Cross-sectional and case-control study; Level of evidence, 3. A total of 2433 baseball players (mean age, 14.5 ± 1.5 years) belonging to junior high school and high school baseball clubs were enrolled. Players completed a questionnaire, and the elbow of each player's throwing arm was assessed by ultrasonography. Participants with abnormal results on ultrasonography were further examined through radiographic study. The OCD lesions were classified into stages based on radiographic results, and demographic data were compared between players with and without OCD lesions. Osteochondritis dissecans of the humeral capitellum was found in 82 (3.4%) elbows by ultrasonography. Players with an OCD lesion began playing baseball at an earlier age (P = .016), had a longer duration of competitive play (P = .0013), and had experienced more present (P = .0025) and past (P < .0001) elbow pain compared with players without a lesion. There were no differences between the 2 groups in the position played (P = .26). Sixty-eight patients underwent further radiographic examination for OCD (radiography, computed tomography, magnetic resonance imaging). Of these players, 10 (14.7%) were classified as having stage I OCD (radiolucent stage); 26 (38.2%), stage II (fragmentation stage); 9 (13.2%), stage III (loose body stage); 9 (13.2%), stage IV (residual stage); and 14 (23.5%), stage V (postoperative stage). The prevalence of OCD of the humeral capitellum, including latent cases, was 3.4% among adolescent baseball players. Players with OCD lesions began playing baseball at earlier ages, had played for longer periods, and had experienced more elbow pain. The player's current baseball position may not be related to the existence of OCD lesions in adolescents. © 2014 The Author(s).

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.

Evaluation of Functional Limitations in Female Soccer Players and Their Relationship with Sports Level – A Cross Sectional Study

PubMed Central

Grygorowicz, Monika; Piontek, Tomasz; Dudzinski, Witold

2013-01-01

The main objective(s) of the study The aim of this study was to analyze: a) abnormalities in the length of lower limb muscles, b) the correctness of movement patterns, and c) the impact of functional limitations of muscles on the correctness of fundamental movement patterns in a group of female soccer players, in relation to their skill level. Materials and Methods 21 female soccer players from Polish Ekstraklasa and 22 players from the 1st Division were tested for lower limb muscle length restrictions and level of fundamental movement skills (with the Fundamental Movement Screen™ test concept by Gray Cook). Chi-square test was used for categorical unrelated variables. Differences between groups in absolute point values were analyzed using the non-parametric Mann-Whitney U test. Statistical significance was set at p<0.05. Results Statistically significant higher number of measurements indicating an abnormal length of rectus femoris was observed in the 1st Division group (p = 0.0433). In the group of Ekstraklasa the authors obtained a significantly higher number of abnormal hamstring test results (p = 0.0006). Ekstraklasa players scored higher in the rotational stability test of the trunk (p = 0.0008), whereas the 1st Division players scored higher in the following tests: deep squat (p = 0.0220), in-line lunge (p = 0.0042) and active straight leg raise (p = 0.0125). The results suggest that there are different functional reasons affecting point values obtained in the FMS™ tests in both analyzed groups. Conclusions The differences in the flexibility of rectus femoris and hamstring muscle observed between female soccer players with different levels of training, may result from a long-term impact of soccer training on the muscle-tendon system and articular structures. Different causes of abnormalities in fundamental movement patterns in both analyzed groups suggest the need for tailoring prevention programs to the level of sport skills represented by the players. PMID:23825579

Everyday music listening and affect regulation: The role of MP3 players

PubMed Central

2013-01-01

The use of digital portable music devices such as MP3 players has rapidly increased during the last decade, and the sheer availability of music offered by such players raises questions about their impact on listeners’ mental and physical health and well-being. This article explores MP3 player use as an everyday tactic for affect regulation, here understood as an individual's efforts to maintain or change the intensity or duration of a given affect. The ability to understand and regulate affects has significant health implications, and among the tactics relevant to such regulation, engagement with music has proven to be particularly successful. The material presented in this article is based on a qualitative interview study focused on MP3 player use as a medium for musical self-care. Because MP3 users can listen to whatever they want, whenever they want, and target their music in the interests of managing and regulating moods and emotions, the MP3 player represents a valuable and convenient technology of affect regulation. PMID:23930987

Everyday music listening and affect regulation: the role of MP3 players.

PubMed

Skånland, Marie Strand

2013-08-07

The use of digital portable music devices such as MP3 players has rapidly increased during the last decade, and the sheer availability of music offered by such players raises questions about their impact on listeners' mental and physical health and well-being. This article explores MP3 player use as an everyday tactic for affect regulation, here understood as an individual's efforts to maintain or change the intensity or duration of a given affect. The ability to understand and regulate affects has significant health implications, and among the tactics relevant to such regulation, engagement with music has proven to be particularly successful. The material presented in this article is based on a qualitative interview study focused on MP3 player use as a medium for musical self-care. Because MP3 users can listen to whatever they want, whenever they want, and target their music in the interests of managing and regulating moods and emotions, the MP3 player represents a valuable and convenient technology of affect regulation.

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

Enhancing Student Success through the Use of Interactive Videodisc Technology.

ERIC Educational Resources Information Center

Pokrass, Richard J.; And Others

Burlington County College in New Jersey has integrated Interactive Videodisc Technology (IVT) into several of its programs, beginning with the college's nursing program. IVT, at its highest level, is a merging of a laser disc player, a personal computer, computer software, and a qualified instructor, designed to bring to students a new dimension…

The Start of Head Start

ERIC Educational Resources Information Center

Neugebauer, Roger

2010-01-01

The creation of the Head Start program occurred at break-neck speed with many dramatic turns and many colorful players. No one tells the story better than Edward Zigler in "Head Start: The Inside Story of America's Most Successful Educational Experiment"--a detailed and personal, behind the scenes look at the program's inception. From this…

Demonstration and Research Program for Teaching Young String Players. Final Report.

ERIC Educational Resources Information Center

Yarborough, William

This report explains a system for rapidly training beginning students in the technical aspects of playing a stringed instrument. The program also affords them a well-rounded, basic knowledge of music. A "numerical" method of notation and concentrated muscular exercises greatly speeded the technical learning process. The daily coordination of ear…

The economic burden of time-loss injuries to youth players participating in week-long rugby union tournaments.

PubMed

Brown, James C; Viljoen, Wayne; Lambert, Mike I; Readhead, Clint; Fuller, Chelsea; Van Mechelen, Willem; Verhagen, Evert

2015-07-01

Rugby Union ("rugby") is a popular sport with high injury risk. Burden of injury is described by the incidence and severity of injury. However reports have ignored the monetary cost of injuries. Therefore the aim of this study was to describe the monetary cost associated with youth rugby injuries. This descriptive study quantified medical treatments of injured players at the South African Rugby Union Youth tournaments in 2011/2012 and the days of work parents missed as a result of the injuries. A health insurer used these data to calculate associated costs. Legal guardians of the 421 injured players were contacted telephonically on a weekly basis until they returned to play. Treatments costs were estimated in South African Rands based on 2013 insurance rates and converted to US$ using purchasing power parities. Of the 3652 players, 2% (n=71) sought medical care after the tournament. For these players, average treatment costs were high (US$731 per player, 95% CI: US$425-US$1096), with fractures being the most expensive type of injury. Players with medical insurance had higher costs (US$937, 95% CI: US$486-US$1500) than those without (US$220, 95% CI: US$145-US$302). Although a minority of players sought follow-up treatment after the tournaments, the cost of these injuries was high. Players without medical insurance having lower costs may indicate that these players did not receive adequate treatment for their injuries. Injury prevention efforts should consider injuries with high costs and the treatment of players without medical insurance. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Neurodegenerative causes of death among retired National Football League players.

PubMed

Lehman, Everett J; Hein, Misty J; Baron, Sherry L; Gersic, Christine M

2012-11-06

To analyze neurodegenerative causes of death, specifically Alzheimer disease (AD), Parkinson disease, and amyotrophic lateral sclerosis (ALS), among a cohort of professional football players. This was a cohort mortality study of 3,439 National Football League players with at least 5 pension-credited playing seasons from 1959 to 1988. Vital status was ascertained through 2007. For analysis purposes, players were placed into 2 strata based on characteristics of position played: nonspeed players (linemen) and speed players (all other positions except punter/kicker). External comparisons with the US population used standardized mortality ratios (SMRs); internal comparisons between speed and nonspeed player positions used standardized rate ratios (SRRs). Overall player mortality compared with that of the US population was reduced (SMR 0.53, 95% confidence interval [CI] 0.48-0.59). Neurodegenerative mortality was increased using both underlying cause of death rate files (SMR 2.83, 95% CI 1.36-5.21) and multiple cause of death (MCOD) rate files (SMR 3.26, 95% CI 1.90-5.22). Of the neurodegenerative causes, results were elevated (using MCOD rates) for both ALS (SMR 4.31, 95% CI 1.73-8.87) and AD (SMR 3.86, 95% CI 1.55-7.95). In internal analysis (using MCOD rates), higher neurodegenerative mortality was observed among players in speed positions compared with players in nonspeed positions (SRR 3.29, 95% CI 0.92-11.7). The neurodegenerative mortality of this cohort is 3 times higher than that of the general US population; that for 2 of the major neurodegenerative subcategories, AD and ALS, is 4 times higher. These results are consistent with recent studies that suggest an increased risk of neurodegenerative disease among football players.

Yo-Yo Intermittent Recovery Test Performance in Subelite Gaelic Football Players From Under Thirteen to Senior Age Groups.

PubMed

Roe, Mark; Malone, Shane

2016-11-01

Roe, M and Malone, S. Yo-Yo intermittent recovery test performance in subelite Gaelic football players from under thirteen to senior age groups. J Strength Cond Res 30 (11): 3187-3193, 2016-Gaelic football is indigenous to Ireland and has similar locomotion profiles to soccer and Australian Football. Given the increasing attention on long-term player development, investigations on age-related variation in Yo-Yo intermittent recovery test level 1 (Yo-YoIR1) performance may provide useful information in talent identification, program design, and player monitoring. Therefore, the aim of this study was to evaluate Yo-YoIR1 performance across Gaelic football age groups. Male participants (n = 355) were recruited from division one, Gaelic football teams. Participants were allocated to one of the 7 groups according to respective age groups from under 13 (U13), under 14, under 15 (U15), under 16 (U16), minor, under 21 (U21), to senior age groups. Total Yo-YoIR1 distance (m) increased progressively from U13 (885 ± 347 m) to U16 (1,595 ± 380 m) equating to a rate of change of 180.2%. In comparison to U13, total distance at minor (1,206 ± 327 m) increased by 136.4%. Subsequent increases were observed in U21 (1,585 ± 445 m) and senior players (2,365 ± 489). Minimum (800-880 m) and maximum (2,240-2,280 m) total distances were comparable for U15, U16, and U21 players. Differences in total distance (m) for all age groups were statistically significant when compared to U13 players (p < 0.002). In comparison to U13 players, the magnitude of differences between age groups for total distance was deemed to be large (effect size > 0.8). Similar trends were observed for maximum velocity and estimated V[Combining Dot Above]O2max. The evolution of Yo-YoIR1 performance in Gaelic football players from adolescents to adulthood highlights how maturation may influence sport-related running ability. Changes in Yo-YoIR1 performance should be closely monitored to optimize interventions for individuals transitioning across age groups.

Prophylactic training in asymptomatic soccer players with ultrasonographic abnormalities in Achilles and patellar tendons: the Danish Super League Study.

PubMed

Fredberg, Ulrich; Bolvig, Lars; Andersen, Niels T

2008-03-01

A recent study published in The American Journal of Sports Medicine showed that asymptomatic soccer players with an increased risk of developing Achilles and patellar tendon injuries within the next 12 months can be identified with use of ultrasonography. Prophylactic eccentric training and stretching can reduce both the frequency of asymptomatic ultrasonographic changes in Achilles and patellar tendons in soccer players and the risk of these asymptomatic intratendinous changes becoming symptomatic. Randomized controlled trial; Level of evidence, 1. Two hundred and nine Danish professional soccer players from the best national league (Super League) were followed over 12 months with use of ultrasonography and injury registration. Half the teams were randomized to an intervention group with prophylactic eccentric training and stretching of the Achilles and patellar tendons during the soccer season. The eccentric training and stretching did not reduce the injury risk, and, contrary to all expectations, the injury risk during the season was increased in players with abnormal patellar tendons at the beginning of the study in January. Eccentric training and stretching in players with normal patellar tendons significantly reduced the proportion of players with ultrasonographic changes in the patellar tendons at the end of the season (risk difference [RD] = 12%; 95% confidence interval [CI], 2%-22%; P = .02), but the training had no effect on the Achilles tendons (RD = 1%; 95% CI, -7% to 9%; P = .75). The presence of preseason ultrasonographic abnormalities in the tendons significantly increased the risk of developing tendon symptoms during the season (relative risk = 1.9; 95% CI, 1.2-3.1; P = .009). This study demonstrates that with the use of ultrasonography, tendon changes in soccer players can be diagnosed before they become symptomatic. The prophylactic eccentric training and stretching program reduces the risk of developing ultrasonographic abnormalities in the patellar tendons but has no positive effects on the risk of injury. On the contrary, in asymptomatic players with ultrasonographically abnormal patellar tendons, prophylactic eccentric training and stretching increased the injury risk.

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. Conclusions Women's basketball players exhibit decreased performance of frontal plane hop tests when compared to women's soccer players. Additionally, the medial triple hop for distance test may be effective at identifying side‐to‐side asymmetries Level of Evidence 3 PMID:28515972

Art critic: Multisignal vision and speech interaction system in a gaming context.

PubMed

Reale, Michael J; Liu, Peng; Yin, Lijun; Canavan, Shaun

2013-12-01

True immersion of a player within a game can only occur when the world simulated looks and behaves as close to reality as possible. This implies that the game must correctly read and understand, among other things, the player's focus, attitude toward the objects/persons in focus, gestures, and speech. In this paper, we proposed a novel system that integrates eye gaze estimation, head pose estimation, facial expression recognition, speech recognition, and text-to-speech components for use in real-time games. Both the eye gaze and head pose components utilize underlying 3-D models, and our novel head pose estimation algorithm uniquely combines scene flow with a generic head model. The facial expression recognition module uses the local binary patterns with three orthogonal planes approach on the 2-D shape index domain rather than the pixel domain, resulting in improved classification. Our system has also been extended to use a pan-tilt-zoom camera driven by the Kinect, allowing us to track a moving player. A test game, Art Critic, is also presented, which not only demonstrates the utility of our system but also provides a template for player/non-player character (NPC) interaction in a gaming context. The player alters his/her view of the 3-D world using head pose, looks at paintings/NPCs using eye gaze, and makes an evaluation based on the player's expression and speech. The NPC artist will respond with facial expression and synthetic speech based on its personality. Both qualitative and quantitative evaluations of the system are performed to illustrate the system's effectiveness.

Examining the Feasibility of Smartphone Game Applications for Physical Activity Promotion in Middle School Students.

PubMed

Blackman, Kacie C A; Zoellner, Jamie; Kadir, Adil; Dockery, Brandon; Johnson, Sallie Beth; Almeida, Fabio A; McCrickard, D Scott; Hill, Jennie L; You, Wen; Estabrooks, Paul A

2015-10-01

The objective of this study was to determine the feasibility (i.e., limited efficacy testing, practicality, and acceptability) of a 6-week smartphone game-based applications program for promoting physical activity (PA) in adolescents in an afterschool program. This mixed-method, quasi-experimental design study included 27 adolescents who evaluated four smartphone PA game-based applications in two Boys & Girls Clubs of America. After an initial baseline week (i.e., usual activity during their visit to the Club), adolescents played each game for 1 week. During a final week, the participants could choose to play any combination of the four games. An established conceptual framework was used to assess feasibility. Efficacy was assessed by changes in PA via wrist-worn accelerometers (model GT3x+; ActiGraph LLC, Pensacola, FL). Practicality was measured through field notes, the number of players attending each session, and the proportion of attendees who played the games. Acceptability was measured using poststudy focus groups. Compared with baseline (3.22 metabolic equivalents [METs]), mean accelerometer values were significantly (P<0.05) higher during "Space Rayders" (4.33 METs) and "Color Hunt" (3.67 METs). Attendance did not differ among games, and weekly number of players averaged 12 of 27 participants. Qualitative findings indicated that participants perceived "Space Rayders" as the most acceptable game. Overall, participants found the games to be enjoyable and easy to use, although they had suggestions to improve graphics and sounds. Smartphone games can be feasible for adolescents to use for PA. Lessons learned will be used to provide improvements for future game development and evaluation.

The Transition Period in Soccer: A Window of Opportunity.

PubMed

Silva, Joao Renato; Brito, Joao; Akenhead, Richard; Nassis, George P

2016-03-01

The aim of this paper is to describe the physiological changes that occur during the transition period in soccer players. A secondary aim is to address the issue of utilizing the transition period to lay the foundation for the succeeding season. We reviewed published peer-reviewed studies if they met the following three selection criteria: (1) the studied population comprised adult soccer players (aged >18 years), (2) time points of physiological and performance assessments were provided, and (3) appropriate statistics for the calculation of effect sizes were reported. Following two selection phases, 12 scientific publications were considered, involving a total sample of 252 players. The transition period elicits small to moderate negative changes in body composition, a moderate decline in sprint performance with and without changes of direction, and small to moderate decrements in muscle power. Detraining effects are also evident for endurance-related physiological and performance outcomes: large decrements in maximal oxygen consumption V̇O2max) and time to exhaustion, and moderate to very large impairments have been observed in intermittent-running performance. Off-season programs should be characterized by clear training objectives, a low frequency of training sessions, and simple training tools in order to facilitate compliance. The program suggested here may constitute the 'minimum effective dose' to maintain or at least attenuate the decay of endurance- and neuromuscular-related performance parameters, as well as restore an adequate strength profile (reduce muscle strength imbalances). This periodization strategy may improve the ability of players to cope with the elevated training demands of pre-season training and therefore reduce the risk of injury. Moreover, this strategy will favor a more efficient development of other relevant facets of performance during the pre-competition phase (e.g., tactical organization). We contend that the transition period needs to be perceived as a 'window of opportunity' for players to both recover and 'rebuild' for the following season.

Making neurorehabilitation fun: Multiplayer training via damping forces balancing differences in skill levels.

PubMed

Baur, Kilian; Wolf, Peter; Riener, Robert; Duarte, Jaime E

2017-07-01

Multiplayer environments are thought to increase the training intensity in robot-aided rehabilitation therapy after stroke. We developed a haptic-based environment to investigate the dynamics of two-player training performing time-constrained reaching movements using the ARMin rehabilitation robot. We implemented a challenge level adaptation algorithm that controlled a virtual damping coefficient to reach a desired success rate. We tested the algorithm's effectiveness in regulating the success rate during game play in a simulation with computer-controlled players, in a feasibility study with six unimpaired players, and in a single session with one stroke patient. The algorithm demonstrated its capacity to adjust the damping coefficient to reach three levels of success rate (low [50%], moderate [70%], and high [90%]) during singleplayer and multiplayer training. For the patient - tested in single-player mode at the moderate success rate only - the algorithm showed also promising behavior. Results of the feasibility study showed that to increase the player's willingness to play at a more challenging task condition, the effect of the challenge level adaptation - regardless of being played in single player or multiplayer mode - might be more important than the provision of multiplayer setting alone. Furthermore, the multiplayer setting tends to be a motivating and encouraging therapy component. Based on these results we will optimize and expand the multiplayer training platform and further investigate multiplayer settings in stroke therapy.

Efficacy of the FIFA 11+ Warm-Up Programme in Male Youth Football: A Cluster Randomised Controlled Trial

PubMed Central

Owoeye, Oluwatoyosi B. A.; Akinbo, Sunday R. A.; Tella, Bosede A.; Olawale, Olajide A.

2014-01-01

The FIFA 11+ is a structured warm-up programme specially designed to prevent injuries among football players from age 14 years and above. However, studies to prove its efficacy are generally few and it is yet to be tested in male youth footballers and among African players. The purpose of the study was to examine the efficacy of the FIFA 11+ programme in reducing the risk of injuries among male youth football players of the Lagos Junior League. A cluster randomised controlled trial was conducted. All the 20 teams (414 players aged 14 -19 years) in the Premier League division were block-randomised into either an intervention (INT) or a control (CON) group. The INT group performed the FIFA 11+ exercises as warm-up during training sessions and the CON group performed usual warm-up. Participating teams were prospectively followed through an entire league season of 6 months in which they were visited every week to assess injured players for time-loss injuries in both groups. The primary outcomes were any injury to the players, injuries by type of exposure and injuries specific to the lower extremities. The secondary outcomes were injuries reported by body location, aetiology, mechanism and severity. In total, 130 injuries were recorded affecting 104 (25%) of the 416 players. Team and player compliance with the INT was 60% and 74% respectively. Based on the primary outcome measures of the study, the FIFA 11+ programme significantly reduced the overall rate of injury in the INT group by 41% [RR = 0.59 (95% CI: 0.40 – 0.86; p = 0.006)] and all lower extremity injuries by 48% [RR = 0.52 (95% CI: 0.34 – 0.82; p = 0.004)]. However, the rate of injury reduction based on secondary outcomes mostly did not reach the level of statistical significance. The FIFA 11+ programme is effective in reducing the rates of injuries in male youth football players. Key points The FIFA 11+ has only been tested in randomised controlled trials conducted on female youth football players; this study reports its efficacy in male youth football for the first time The FIFA 11+ programme significantly reduced the overall rate of injuries and lower extremity injuries in male youth football players Youth football administrators in Africa and other parts of the world should pursue the implementation of the FIFA 11+ in order to minimize the incidence of injuries among players PMID:24790486

Technical performance and match-to-match variation in elite football teams.

PubMed

Liu, Hongyou; Gómez, Miguel-Angel; Gonçalves, Bruno; Sampaio, Jaime

2016-01-01

Recent research suggests that match-to-match variation adds important information to performance descriptors in team sports, as it helps measure how players fine-tune their tactical behaviours and technical actions to the extreme dynamical environments. The current study aims to identify the differences in technical performance of players from strong and weak teams and to explore match-to-match variation of players' technical match performance. Performance data of all the 380 matches of season 2012-2013 in the Spanish First Division Professional Football League were analysed. Twenty-one performance-related match actions and events were chosen as variables in the analyses. Players' technical performance profiles were established by unifying count values of each action or event of each player per match into the same scale. Means of these count values of players from Top3 and Bottom3 teams were compared and plotted into radar charts. Coefficient of variation of each match action or event within a player was calculated to represent his match-to-match variation of technical performance. Differences in the variation of technical performances of players across different match contexts (team and opposition strength, match outcome and match location) were compared. All the comparisons were achieved by the magnitude-based inferences. Results showed that technical performances differed between players of strong and weak teams from different perspectives across different field positions. Furthermore, the variation of the players' technical performance is affected by the match context, with effects from team and opposition strength greater than effects from match location and match outcome.

Head impacts in a junior rugby league team measured with a wireless head impact sensor: an exploratory analysis.

PubMed

King, Doug; Hume, Patria; Gissane, Conor; Clark, Trevor

2017-01-01

OBJECTIVE The aim of this study was to investigate the frequency, magnitude, and distribution of head impacts sustained by players in a junior rugby league over a season of matches. METHODS The authors performed a prospective cohort analysis of impact magnitude, frequency, and distribution on data collected with instrumented XPatches worn behind the ear of players in an "under-11" junior rugby league team (players under 11 years old). RESULTS A total of 1977 impacts were recorded. Over the course of the study, players sustained an average of 116 impacts (average of 13 impacts per player per match). The measured linear acceleration ranged from 10g to 123g (mean 22g, median 16g, and 95th percentile 57g). The rotational acceleration ranged from 89 rad/sec 2 to 22,928 rad/sec 2 (mean 4041 rad/sec 2 , median 2773 rad/sec 2 , and 95th percentile 11,384 rad/sec 2 ). CONCLUSIONS The level of impact severity based on the magnitude of impacts for linear and rotational accelerations recorded was similar to the impacts reported in studies of American junior and high school football, collegiate football, and youth ice hockey players, but the players in the rugby league cohort were younger, had less body mass, and played at a slower speed than the American players. Junior rugby league players are required to tackle the player to the ground and use a different tackle technique than that used in American football, likely increasing the rotational accelerations recorded at the head.

Modeling the Player: Predictability of the Models of Bartle and Kolb Based on NEO-FFI (Big5) and the Implications for Game Based Learning

ERIC Educational Resources Information Center

Konert, Johannes; Gutjahr, Michael; Göbel, Stefan; Steinmetz, Ralf

2014-01-01

For adaptation and personalization of game play sophisticated player models and learner models are used in game-based learning environments. Thus, the game flow can be optimized to increase efficiency and effectiveness of gaming and learning in parallel. In the field of gaming still the Bartle model is commonly used due to its simplicity and good…

Framework Support For Knowledge-Based Software Development

NASA Astrophysics Data System (ADS)

Huseth, Steve

1988-03-01

The advent of personal engineering workstations has brought substantial information processing power to the individual programmer. Advanced tools and environment capabilities supporting the software lifecycle are just beginning to become generally available. However, many of these tools are addressing only part of the software development problem by focusing on rapid construction of self-contained programs by a small group of talented engineers. Additional capabilities are required to support the development of large programming systems where a high degree of coordination and communication is required among large numbers of software engineers, hardware engineers, and managers. A major player in realizing these capabilities is the framework supporting the software development environment. In this paper we discuss our research toward a Knowledge-Based Software Assistant (KBSA) framework. We propose the development of an advanced framework containing a distributed knowledge base that can support the data representation needs of tools, provide environmental support for the formalization and control of the software development process, and offer a highly interactive and consistent user interface.

The effect of sprinting after each set of heavy resistance training on the running speed and jumping performance of young basketball players.

PubMed

Tsimahidis, Konstantinos; Galazoulas, Christos; Skoufas, Dimitrios; Papaiakovou, Georgios; Bassa, Eleni; Patikas, Dimitrios; Kotzamanidis, Christos

2010-08-01

The purpose of this study was to investigate the effect of a 10-week heavy resistance combined with a running training program on the strength, running speed (RS), and vertical jump performance of young basketball players. Twenty-six junior basketball players were equally divided in 2 groups. The control (CON) group performed only technical preparation and the group that followed the combined training program (CTP) performed additionally 5 sets of 8-5 repetition maximum (RM) half squat with 1 30-m sprint after each set. The evaluation took place before training and after the 5th and 10th weeks of training. Apart from the 1RM half squat test, the 10- and 30-m running time was measured using photocells and the jump height (squat, countermovement jump, and drop jump) was estimated taking into account the flight time. The 1RM increased by 30.3 +/- 1.5% at the 10th week of training for the CTP group (p < 0.05), whereas the CON group showed no significant increase (1.1 +/- 1.6%, p > 0.05). In general, all measured parameters showed a statistically significant increase after the 5th and 10th weeks (p < 0.05), in contrast to the CON group (p > 0.05). This suggests that the applied CTP is beneficial for the strength, RS, and jump height of young basketball players. The observed adaptations in the CTP group could be attributed to learning factors and to a more optimal transfer of the strength gain to running and jumping performance.

The Effect of Regular-Season Rest on Playoff Performance Among Players in the National Basketball Association.

PubMed

Belk, John W; Marshall, Hayden A; McCarty, Eric C; Kraeutler, Matthew J

2017-10-01

There has been speculation that rest during the regular season for players in the National Basketball Association (NBA) improves player performance in the postseason. To determine whether there is a correlation between the amount of regular-season rest among NBA players and playoff performance and injury risk in the same season. Cohort study; Level of evidence, 3. The Basketball Reference and Pro Sports Transactions archives were searched from the 2005 to 2015 seasons. Data were collected on players who missed fewer than 5 regular-season games because of rest (group A) and 5 to 9 regular-season games because of rest (group B) during each season. Inclusion criteria consisted of players who played a minimum of 20 minutes per game and made the playoffs that season. Players were excluded if they missed ≥10 games because of rest or suspension or missed ≥20 games in a season for any reason. Matched pairs were formed between the groups based on the following criteria: position, mean age at the start of the season within 2 years, regular-season minutes per game within 5 minutes, same playoff seeding, and player efficiency rating (PER) within 2 points. The following data from the playoffs were collected and compared between matched pairs at each position (point guard, shooting guard, forward/center): points per game, assists per game, PER, true shooting percentage, blocks, steals, and number of playoff games missed because of injury. A total of 811 players met the inclusion and exclusion criteria (group A: n = 744 players; group B: n = 67 players). Among all eligible players, 27 matched pairs were formed. Within these matched pairs, players in group B missed significantly more regular-season games because of rest than players in group A (6.0 games vs 1.3 games, respectively; P < .0001). There were no significant differences between the groups at any position in terms of points per game, assists per game, PER, true shooting percentage, blocks, steals, or number of playoff games missed because of injury. Rest during the NBA regular season does not improve playoff performance or affect the injury risk during the playoffs in the same season.

Use of behavioral biometrics in intrusion detection and online gaming

NASA Astrophysics Data System (ADS)

Yampolskiy, Roman V.; Govindaraju, Venu

2006-04-01

Behavior based intrusion detection is a frequently used approach for insuring network security. We expend behavior based intrusion detection approach to a new domain of game networks. Specifically, our research shows that a unique behavioral biometric can be generated based on the strategy used by an individual to play a game. We wrote software capable of automatically extracting behavioral profiles for each player in a game of Poker. Once a behavioral signature is generated for a player, it is continuously compared against player's current actions. Any significant deviations in behavior are reported to the game server administrator as potential security breaches. Our algorithm addresses a well-known problem of user verification and can be re-applied to the fields beyond game networks, such as operating systems and non-game networks security.

Using Games To Explore The Nexus of Climate, Energy, and Water

NASA Astrophysics Data System (ADS)

Hall, M. K.; Mayhew, M. A.

2012-12-01

We have developed a set of card games to teach teens and adults about the interdependency of energy demand, water consumption, and climate change, which we term the nexus of energy, water, and climate. The latest game challenges players to construct arguments around issues related to the nexus, such as the benefits of carbon sequestration or the negative impacts of consuming corn biofuel. The game has been through several rounds of playtesting, both with teens and adults, and in formal and informal learning environments, such as our ongoing teen Cafe Scientifique program (www.cafenm.org). The card game consists of two types of cards, "Challenge" and "Policy." Each round, one player acting as the Judge draws a Challenge card and reads the adjective—for example, dangerous, clean, catastrophic, awesome— and its definition displayed on the card. The other players hold Policy cards containing 3 or 4 facts related to nexus concepts. For example, the Algae bio-diesel fuel policy card contains the fact, "Algae can produce 100 times more fuel per acre that any other biofuel crop". A fact on the Tight shale gas policy card reads, "Chemicals used in 'fracking' can contaminate water supplies." Using the facts on a single Policy card, each player constructs an argument aligned with the adjective—and presents it to the Judge. This requires players to synthesize the given facts and any prior knowledge about the topic into a coherent argument. As players make their arguments, everyone is challenged to think about the nuances and implications of the myriad choices we have in balancing the needs for water and energy resources with the challenge of minimizing climate change. The Judge decides which player makes the policy argument that best aligns with the adjective, and that player wins the round. Players take turns being the Judge. The first player to win three rounds wins the game. The game has been well received by both teen and adult audiences. It is a highly social game and fun to play, while conveying a rich variety of concepts related to the nexus of energy, water, and climate. We are happy to share the draft game with any who would like to playtest it with their own audiences.

Does Digital Game Interactivity Always Promote Self-Efficacy?

PubMed

Lee, Yu-Hao

2015-11-01

Interactive digital games can promote self-efficacy by engaging players in enactive and observational learning. However, interactivity does not always lead to greater self-efficacy. Important constructs in social cognitive theory, such as performance outcome and perceived similarity, are often not accounted for in studies that have tested the effect of digital game interactivity on self-efficacy. This study assessed the effects of interactive digital games compared with passive digital games based on video comparison, a common experimental design used to test the effect of digital game interactivity on self-efficacy. In addition, this study also evaluated player performance and measured perceived similarity to the observed player. Findings suggested that in general, digital game interactivity predicted higher self-efficacy compared with noninteractive passive games. However, in the noninteractive conditions, the effects of performance on self-efficacy were moderated by perceived similarity between the observer and the observed player. When the observed player was perceived to be similar to the observer, the effects of performance on self-efficacy were comparable to the interactive game, but when the observed player was perceived as dissimilar to the observer, observing the dissimilar player failed to increase observer self-efficacy. Implications for interactivity manipulations and game developers are discussed.

Expert-novice differences in cognitive and execution skills during tennis competition.

PubMed

Del Villar, Fernando; García González, Luis; Iglesias, Damián; Perla Moreno, M; Cervelló, Eduardo M

2007-04-01

This study deals with decision and execution behavior of tennis players during competition. The study is based on the expert-novice paradigm and aims to identify differences between both groups in the decision-making and execution variables in serve and shot actions in tennis. Six expert players (elite Spanish tennis players) and six novice players (grade school tennis players) took part in this study. To carry out this study, the observation protocol defined by McPherson and Thomas in 1989, in which control, decision-making and execution variables were included, was used, where it was applied to the performance of the tennis player in a real match situation. In the analysis, significant differences between experts and novices in decision-making and execution variables are found wherein it can be observed that experts display a greater ability to make the appropriate decisions, selecting the most tactical responses to put pressure on the opponent. Expert tennis players were also able to carry out forceful executions to their opponent with greater efficiency, making the opponent's response to a large extent more difficult. These findings are in accordance with those of McPherson and colleagues.

Why do English players fail in soccer penalty shootouts? A study of team status, self-regulation, and choking under pressure.

PubMed

Jordet, Geir

2009-01-15

I examine why players from some nations appear always to choke in major international soccer penalty shootouts. Based on a model on choking under pressure as a type of self-defeating behaviour (Baumeister, 1997), I hypothesized that highly favourable public appraisals of a team would be linked to displays of escapist self-regulation strategies and inferior performance. I selected the eight most merited European nations, obtained videos from penalty shootouts in two major international tournaments (World Cup and European Championships), and analysed all 200 shots taken by players representing these teams. The results showed significant relationships between team status, self-regulation strategies, and performance. Players from countries that, at the time of the penalty shootout, either had many international club titles or featured many internationally decorated players, spent less time preparing their shots and were less successful from the penalty spot than players from countries with lower public status. England and Spain are used to illustrate these effects, as the data suggest that players from these two countries may have underperformed in previous international soccer tournaments because of high public status and misguided self-regulation strategies.

Huggable Communication Medium Maintains Level of Trust during Conversation Game.

PubMed

Takahashi, Hideyuki; Ban, Midori; Osawa, Hirotaka; Nakanishi, Junya; Sumioka, Hidenobu; Ishiguro, Hiroshi

2017-01-01

There have been several attempts in recent years to develop a remote communication device using sensory modalities other than speech that would induce a user's positive experience with his/her conversation partner. Specifically, Hugvie is a human-shaped pillow as well as a remote communication device enabling users to combine a hugging experience with telecommunication to improve the quality of remote communication. The present research is based on the hypothesis that using Hugvie maintains users' level of trust toward their conversation partners in situations prone to suspicion. The level of trust felt toward other remote game players was compared between participants using Hugvie and those using a basic communication device while playing a modified version of Werewolf , a conversation-based game, designed to evaluate trust. Although there are always winners and losers in the regular version of Werewolf , the rules were modified to generate a possible scenario in which no enemy was present among the players and all players would win if they trusted each other. We examined the effect of using Hugvie while playing Werewolf on players' level of trust toward each other and our results demonstrated that in those using Hugvie , the level of trust toward other players was maintained.

The last straw!: a tool for participatory education about the social determinants of health.

PubMed

Rossiter, Kate; Reeve, Kate

2008-01-01

In response to a scarcity of teaching tools regarding the social determinants of health (SDOH), Kate Reeve and Kate Rossiter created The Last Straw! board game, an innovative participatory education tool to facilitate and engage critical thinking about the SDOH. The Last Straw! is designed to encourage discussion about the SDOH, promote critical thinking, and build empathy with marginalized people. The game begins as each player rolls the dice to create a character profile, including socioeconomic status (SES), race, and gender. Based on this profile, players then receive a certain number of "vitality chips." Moving across the board, players encounter scenarios that cause them to gain and lose chips based on their profile. The player who finishes the game with the most chips wins the game. The game can be facilitated for a variety of audiences, including both players with no prior knowledge of the SDOH and those experienced in the field. The game has been played with students, policymakers, and community workers, among others, and has been met with immense enthusiasm. Here, we detail the game's reception within the community, including benefits, limitations, and next steps.

Provider Perspectives on Evidence-Based HIV Prevention Interventions: Barriers and Facilitators to Implementation

PubMed Central

Dickson-Gomez, Julia

2011-01-01

Abstract Since the beginning of the HIV/AIDS epidemic, community-based organizations (CBOs) have been key players in combating this disease through grassroots prevention programs and close ties to at-risk populations. Increasingly, both funding agencies and public health institutions require that CBOs implement evidence-based HIV prevention interventions, most of which are researcher developed. However, after completing training for these evidence-based interventions (EBIs), agencies may either abandon plans to implement them or significantly modify the intervention. Based on 22 semistructured interviews with HIV prevention service providers, this article explores the barriers and facilitators to dissemination and implementation of EBIs included in the Centers for Disease Control and Prevention's (CDC) Diffusion of Effective Behavioral Interventions (DEBI) program. Results suggest that there is a tension between the need to implement interventions with fidelity and the lack of guidance on how to adapt the interventions for their constituencies and organizational contexts. Findings suggest the need for HIV prevention intervention development and dissemination that integrate community partners in all phases of research and dissemination. PMID:21323564

Return-to-Play Outcomes in Professional Baseball Players After Medial Ulnar Collateral Ligament Injuries: Comparison of Operative Versus Nonoperative Treatment Based on Magnetic Resonance Imaging Findings.

PubMed

Ford, Gregory M; Genuario, James; Kinkartz, Jason; Githens, Thomas; Noonan, Thomas

2016-03-01

The medial ulnar collateral ligament (UCL) is the primary static stabilizer to valgus stress of the elbow. Injuries to the UCL are common in baseball pitchers. In the 1970s, reconstructive surgery was developed. Return-to-play (RTP) rates of 67% to 95% after reconstruction have been reported. There is a paucity of published studies among professional baseball players reporting RTP with nonoperative treatment. To identify professional baseball players' ability to RTP after the nonoperative treatment of UCL injuries based on the magnetic resonance imaging (MRI) grade. Case series; Level of evidence, 4. A review of elbow injuries among a professional baseball organization from 2006 to 2011 was performed. MRI was performed on all players. Forty-three UCL injuries were diagnosed. Treatment included rehabilitation, surgery, or both. Rates of RTP and return to the same level of play or higher (RTSP) were calculated and correlated with the MRI grade, location of injury, and player position. MRI grading was as follows: I, intact ligament with or without edema; IIA, partial tear; IIB, chronic healed injury; and III, complete tear. Forty-three UCL injuries in 43 players were diagnosed. Eight had complete tears (grade III), were treated operatively with UCL reconstruction, and had an RTP rate of 75% and RTSP rate of 63% (5/8 returned to the same level and 1 to a lower level). All 8 were pitchers. The remaining 35 players had incomplete injuries (4 grade I, 8 grade IIA, and 23 grade IIB), consisting of 24 pitchers and 11 positional players. Of these 35 players, 1 underwent surgery without attempted rehabilitation, 3 initiated rehabilitation until MRI was performed and then underwent surgery, and 3 underwent surgery after failed rehabilitation. The 7 players who underwent UCL reconstruction surgery had an RTP rate of 100% and RTSP rate of 86% (6/7 returned to the same level and 1 to a lower level). The remaining 28 with nonoperative treatment had both RTP and RTSP rates of 93% (26/28 returned to the same level and 0 to a lower level). Of these, 10 were positional players with an RTSP rate of 90%, and 18 were pitchers with an RTSP rate of 94%. Of all players with incomplete UCL injuries who completed nonoperative rehabilitative treatment (n = 31), 26 had a successful RTSP (84%). Incomplete UCL injuries in professional baseball players can be successfully treated nonoperatively in the majority of cases. Pitchers are more likely to have complete tears leading to surgery. MRI grading of UCL injuries can help predict RTP and the need for surgery. © 2016 The Author(s).

Flood and Coastal Storm Damage Reduction Program. Beach-fx User’s Manual: Version 1.0

DTIC Science & Technology

2009-08-01

Shapefile Import Template Attribute Fields ............................................................. 103 Appendix B: General Description of Output...Reordering map players . ....................................................................................................... 24 Figure 20. Map display...94 Figure 68. Field calculator

Serious Games for Parkinson's Disease Fine Motor Skills Rehabilitation Using Natural Interfaces.

PubMed

Foletto, Antônio Augusto; Cordeiro d'Ornellas, Marcos; Cervi Prado, Ana Lucia

2017-01-01

Parkinson's Disease rehabilitation can be long and boring being difficult to maintain patient engagement on therapy programs. Novel technologies are allowing computer games to be played throught natural interfaces. This paper presents the development and assessment of a system of serious games for fine motor skills rehabilitation using natural interfaces. The games were assessed throught a questionnaire that evaluated the game experience through seven components: immersion, flow, competence, tension, challenge and positive and negative affect. In addition, a conceptual framework for development of serious games for fine motor skills rehabilitation was proposed. The results from the quantitative questionnaire suggested that the player experience was positive on all components assessed. Also, player experience between the three games was statistically the same, implying that the games can be used with consistency in a physical therapy rehabilitation program.

Bridging the gap between empirical results, actual strategies, and developmental programs in soccer.

PubMed

Figueiredo, António J; Gonçalves, Carlos E; Tessitore, Antonio

2014-05-01

Being one of the most prominent globalized sports, soccer played at club, national, and continental levels has a relevant societal role. At present, the specific competencies, interests, and languages of the different actors involved in the selection, development, and support of long-lasting careers of players might limit opportunities for potential talented players. Unless the cultural environment of soccer resolves the gaps between empirical results and actual soccer strategies, scientific discussion relating to the effectiveness of talent selection and development remains limited. This commentary is intended to highlight the need for developmental programs to prepare soccer personnel for a transdisciplinary dialogue, which could foster a future development of this sport. Finally, in considering the wide soccer-related employment opportunities at local, national, and international levels, the need for a clear qualification framework is crucial.

Predictors of FIFA 11+ Implementation Intention in Female Adolescent Soccer: An Application of the Health Action Process Approach (HAPA) Model

PubMed Central

McKay, Carly D.; Merrett, Charlotte K.; Emery, Carolyn A.

2016-01-01

The Fédération Internationale de Football (FIFA) 11+ warm-up program is efficacious at preventing lower limb injury in youth soccer; however, there has been poor adoption of the program in the community. The purpose of this study was to determine the utility of the Health Action Process Approach (HAPA) behavior change model in predicting intention to use the FIFA 11+ in a sample of 12 youth soccer teams (coaches n = 10; 12–16 year old female players n = 200). A bespoke cross-sectional questionnaire measured pre-season risk perceptions, outcome expectancies, task self-efficacy, facilitators, barriers, and FIFA 11+ implementation intention. Most coaches (90.0%) and players (80.0%) expected the program to reduce injury risk but reported limited intention to use it. Player data demonstrated an acceptable fit to the hypothesized model (standardized root mean square residual (SRMR) = 0.08; root mean square of error of approximation (RMSEA) = 0.06 (0.047–0.080); comparative fit index (CFI) = 0.93; Tucker Lewis index (TLI) = 0.91) Task self-efficacy (β = 0.53, p ≤ 0.01) and outcome expectancies (β = 0.13 p ≤ 0.05) were positively associated with intention, but risk perceptions were not (β = −0.02). The findings suggest that the HAPA model is appropriate for use in this context, and highlight the need to target task self-efficacy and outcome expectancies in FIFA 11+ implementation strategies. PMID:27399746

Nutritional recommendations for water polo.

PubMed

Cox, Gregory R; Mujika, Iñigo; van den Hoogenband, Cees Rein

2014-08-01

Water polo is an aquatic team sport that requires endurance, strength, power, swimming speed, agility, tactical awareness, and specific technical skills, including ball control. Unlike other team sports, few researchers have examined the nutritional habits of water polo athletes or potential dietary strategies that improve performance in water polo match play. Water polo players are typically well muscled, taller athletes; female players display higher levels of adiposity compared with their male counterparts. Positional differences exist: Center players are heavier and have higher body fat levels compared with perimeter players. Knowledge of the physical differences that exist among water polo players offers the advantage of player identification as well as individualizing nutrition strategies to optimize desired physique goals. Individual dietary counseling is warranted to ensure dietary adequacy, and in cases of physique manipulation. Performance in games and during quality workouts is likely to improve by adopting strategies that promote high carbohydrate availability, although research specific to water polo is lacking. A planned approach incorporating strategies to facilitate muscle glycogen refueling and muscle protein synthesis should be implemented following intensified training sessions and matches, particularly when short recovery times are scheduled. Although sweat losses of water polo players are less than what is reported for land-based athletes, specific knowledge allows for appropriate planning of carbohydrate intake strategies for match play and training. Postgame strategies to manage alcohol intake should be developed with input from the senior player group to minimize the negative consequences on recovery and player welfare.

Do cognitive training strategies improve motor and positive psychological skills development in soccer players? Insights from a systematic review.

PubMed

Slimani, Maamer; Bragazzi, Nicola Luigi; Tod, David; Dellal, Alexandre; Hue, Olivier; Cheour, Foued; Taylor, Lee; Chamari, Karim

2016-12-01

Soccer players are required to have well-developed physical, technical and cognitive abilities. The present systematic review, adhering to Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines, examined the effects of cognitive training strategies on motor and positive psychological skills development in soccer performance and identified the potential moderators of the "cognitive training-soccer performance" relationship. Thirteen databases were systematically searched using keywords related to psychological or cognitive training in soccer players. The review is based on 18 studies, employing 584 soccer players aged 7-39 years. Cognitive strategies, particularly imagery, appear to improve sports performance in soccer players. Regarding imagery, the combination of two different types of cognitive imagery training (i.e., cognitive general and cognitive specific) has a positive influence on soccer performance during training, whereas motivational imagery (i.e., motivational general-arousal, motivational general-mastery and motivational specific) enhance competition performance. Younger soccer players employ cognitive general and cognitive specific imagery techniques to a greater extent than older soccer players. Combined cognitive training strategies were more beneficial than a single cognitive strategy relative to motor skills enhancement in elite (particularly midfielders) and amateur (i.e., when practising complex and specific soccer skills in precompetitive period) soccer players. In conclusion, it appears that there are differences in cognitive/psychological training interventions, and their efficacy, according to whether they are directed towards training or competition, and the age, standard and playing position of the players.

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 involve rugby players across the research cycle of a player health study, ensure the study is player-centred, and that players had approved and informed the design of the study and its questionnaire from their playing experiences. Methods Two group discussions were undertaken with current students who were playing rugby at a Collegiate University. All male and female University rugby players and two College rugby teams were approached to become involved. Sessions were chaired by a player-lead using a topic guide and were audio-recorded and transcribed. Player suggestions were extracted by the player-lead and discussed within the study team for inclusion in the player health study and its questionnaire. Results Players readily engaged with the sessions and made many contributions to the development of the study and the questionnaire. Players discussed whether certain topics were being collected satisfactorily, and whether the questionnaire would encompass their playing experiences or that of other players. Players suggested where answers might be less reliable, and ways in which this could be improved. Players recommended additions to the questionnaire, and questioned researchers on the choice of language, motivation for question inclusion and if measures were standardised or novel. Alterations were made to the questionnaire based on suggestions, where these were agreed by the study team. Conclusions Involving a group of players in the design of a player health study and questionnaire was not an arduous process and was rewarding for researchers. The process resulted in numerous alterations to the questionnaire and its functionality, which may improve response rate, the experience of players participating in the player health study, and their ability to report relevant information aligned with their previous experience. Player involvement in research was feasible to implement and improved not only the questionnaire, but also researcher confidence in the project and player experiences being accurately captured and leading a reliable data collection processes in a population with the potential for cultural bias to affect the ascertainment of health, pain and injury.

Physical Attributes and NFL Combine Performance Tests Between Italian National League and American Football Players: A Comparative Study.

PubMed

Vitale, Jacopo A; Caumo, Andrea; Roveda, Eliana; Montaruli, Angela; La Torre, Antonio; Battaglini, Claudio L; Carandente, Franca

2016-10-01

Vitale, JA, Caumo, A, Roveda, E, Montaruli, A, La Torre, A, Battaglini, CL, and Carandente, F. Physical attributes and NFL Combine performance tests between Italian National League and American football players: a comparative study. J Strength Cond Res 30(10): 2802-2808, 2016-The purpose of this study was to examine anthropometric measurements and the results of a battery of performance tests administered during the National Football League (NFL) Combine between American football players who were declared eligible to participate in the NFL Combine and football players of a top Italian team (Rhinos Milan). Participants (N = 50) were categorized by position into 1 of 3 groups based on playing position: skill players (SP) included wide receivers, cornerbacks, free safeties, strong safeties, and running backs; big skill players (BSP) consisted of fullbacks, linebackers, tight ends, and defensive ends; lineman (LM) included centers, offensive guards, offensive tackles, and defensive tackles. A 1-way analysis of variance followed by the Tukey-Kramer post hoc test was used for comparisons between Italian players by playing position. Ninety-five percent CIs were used for comparisons between American and Italian football for the NFL Combine performance tests. Significant differences for all the variables between the 3 playing categories were observed among the Italian players; LM had higher anthropometric and body composition values than SP (p < 0.001) and BSP (p < 0.001), whereas LM performed significantly worse in the physical tests, except for the 225-lb bench press test when compared with SP (p < 0.002). American football players presented significantly higher anthropometric values and test performance scores when compared with Italian players. Administrators of professional football teams in Italy need to improve the player's physical attributes, so the gap that currently exists between American and Italian players can be reduced, which could significantly improve the quality of American football in Italy.

Strength and Jump Biomechanics of Elite and Recreational Female Youth Soccer Players

PubMed Central

Chrisman, Sara P.; O'Kane, John W.; Polissar, Nayak L.; Tencer, Allan F.; Mack, Christopher D.; Levy, Marni R.; Schiff, Melissa A.

2012-01-01

Context Most researchers investigating soccer injuries have studied elite athletes because they have greater athletic-exposure hours than other athletes, but most youth participate at the recreational level. If risk factors for injury vary by soccer level, then recommendations generated using research with elite youth soccer players might not generalize to recreational players. Objective To examine injury risk factors of strength and jump biomechanics by soccer level in female youth athletes and to determine whether research recommendations based on elite youth athletes could be generalized to recreational players. Design Cross-sectional study. Setting Seattle Youth Soccer Association. Patients or Other Participants Female soccer players (N = 92) aged 11 to 14 years were recruited from 4 randomly selected elite (n = 50; age = 12.5 years, 95% confidence interval [95% CI]) = 12.3, 12.8 years; height = 157.8 cm, 95% CI = 155.2, 160.3 cm; mass = 49.9 kg, 95% CI = 47.3, 52.6 kg) and 4 randomly selected recreational (n = 42; age = 13.2 years, 95% CI = 13.0, 13.5 years; height = 161.1 cm, 95% CI = 159.2, 163.1 cm; mass = 50.6 kg, 95% CI = 48.3, 53.0 kg) soccer teams. Main Outcome Measure(s) Players completed a questionnaire about demographics, history of previous injury, and soccer experience. Physical therapists used dynamometry to measure hip strength (abduction, adduction, extension, flexion) and knee strength (flexion, extension) and Sportsmetrics to measure vertical jump height and jump biomechanics. We compared all measurements by soccer level using linear regression to adjust for age and mass. Results Elite players were similar to recreational players in all measures of hip and knee strength, vertical jump height, and normalized knee separation (a valgus estimate generated using Sportsmetrics). Conclusions Female elite youth players and recreational players had similar lower extremity strength and jump biomechanics. This suggests that recommendations generated from research with elite youth soccer players could be generalized to recreational players. PMID:23182007

Energy cost and game flow of 5 exer-games in trained players.

PubMed

Bronner, Shaw; Pinsker, Russell; Noah, J Adam

2013-05-01

To determine energy expenditure and player experience in exer-games designed for novel platforms. Energy cost of 7 trained players was measured in 5 music-based exer-games. Participants answered a questionnaire about "game flow," experience of enjoyment, and immersion in game play. Energy expenditure during game play ranged from moderate to vigorous intensity (4 - 9 MET). Participant achieved highest MET levels and game flow while playing StepMania and lowest MET levels and game flow when playing Wii Just Dance 3(®) and Kinect Dance Central™. Game flow scores positively correlated with MET levels. Physiological measurement and game flow testing during game development may help to optimize exer-game player activity and experience.

Defining the Process of a Cardiovascular Risk Assessment Program: Lessons Learnt From Cardiac Assessment of Elite Soccer Players in the United Kingdom.

PubMed

Speers, Christopher; Seth, Ajai Narain; Patel, Kiran Chhaganbhai; Rakhit, Dhrubo Jyoti; Gillett, Mark James

2017-12-14

Retrospectively analyze the cardiac assessment process for elite soccer players, and provide team physicians with a systematic guide to managing longitudinal cardiac risk. Descriptive Epidemiology Study. Cardiac assessments incorporating clinical examination, 12-lead ECG, echocardiography, and health questionnaire. Soccer players at 5 professional clubs in England, the United Kingdom. Data was retrospectively collected, inspected, and analyzed to determine their clinical management and subsequent follow-up. Over 2 years, 265 soccer players, aged 13 to 37 years with 66% of white European ethnicity, were included in the cohort. Eleven percent had "not-normal" assessments, of these assessments, 83% were considered gray screens, falling into three broad categories: structural cardiac features (including valvular abnormalities), functional cardiac features, and electrocardiogram changes. After cardiology consultation, all assessments were grouped into low, enhanced and high-risk categories for ongoing longitudinal risk management. Overall clear-cut pathology was identified in 2%. Cardiovascular assessment is a vital tool in identifying athletes at risk of sudden cardiac death to mitigate their risk through surveillance, intervention, or participation restriction. The decision whether a player is fit to play or not requires a robust risk assessment followed by input from a multidisciplinary team that includes both the team physician and cardiologist. This educational article proposes a clinical management pathway to aid clinicians with this process. Sudden cardiac death is the important medical cause of death during exercise. The team physician should assume responsibility for the management of the longitudinal risk of their players' cardiac assessments in conjunction with sports cardiologist.

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.

Agility and change of direction in soccer: differences according to the player ages.

PubMed

Fiorilli, Giovanni; Mitrotasios, Michalis; Iuliano, Enzo; Pistone, Eugenio M; Aquino, Giovanna; Calcagno, Giuseppe; DI Cagno, Alessandra

2017-12-01

The goal of this study was to compare the changes of direction speed (CODS) and reactive agility (RA) in soccer players of different ages, in order to optimize the best training of these skills. One hundred eighty-seven players, divided into bi-annual age-groups, U12, U14, U16 and U18, performed two tests: Y-Agility Test, carried out in planned and reactive mode (Y-PLAN and Y-REAC) and Illinois for Change of Direction Test (ICODT). Difference between Y-REAC minus Y-PLAN represents the index of reactivity (REAC-INDEX). MANOVA showed significant differences among groups (F3,182=14.591; P<0.01; η2p=0.244). Y-PLAN showed significant differences only between U12 and the other groups (P<0.01). ICODT results were significantly different between the groups U12 and U14 and the other groups (P<0.01). Significant Pearson's correlations between Y-TEST and ICODT, for the three categories of young players (0.398 P<0.05; 0.615 P<0.01; 0.608 P<0.01 respectively), were found, whereas no significant correlation was found in U18 group. The best performance of Y-PLAN and ICODT, through age, depends on physical skill level, whereas the best RA results depend on technique and experience that help the players to use anticipatory skill. The high correlations between CODS and RA performances, differently than adult athletes, suggest that an effective work program for young players may include RA and CODS training at the same time.

Wumpus Advisor I. A First Implementation of a Program That Tutors Logical and Probabilistic Reasoning Skills. AI Memo 381.

ERIC Educational Resources Information Center

Stansfield, James L.; And Others

An Intelligent Computer Aided Instruction (ICAI) program that incorporates an Expert module which allows the tutor to compare the student's response to those generated by an expert was developed for use with Wumpus, a simple maze-exploration game. The Wumpus Advisor program offers advice to a player involved in choosing the best move in a game for…

Space industrialization: A national perspective

NASA Technical Reports Server (NTRS)

Reis, V. H.

1984-01-01

Space industrialization (or commercialization) has the potential to be a major player in America's space program. If this potential is to be realized, however, industrialization efforts must be considered within the context of the other major portions of the space program: shuttle, space station, and civil remote sensing. Further, development efforts must be based upon a sound scientific and technical understanding of the products and processes, and there must be a trained cadre of dedicated individuals willing to devote time and effort to this effort. There remain considerable risks and uncertainties. Given all this, the best path to follow would seem to be a long term, balanced commitment, emphasizing government, industry, and academia partnerships. Several points are addressed: (1) the place of space industrialization in the overall national space program; (2) the meaning of space industrialization with respect to the historic, national aims of space; and (3) specifically what is being industrialized.

Hematological parameters and anaerobic threshold in Brazilian soccer players throughout a training program.

PubMed

Silva, A S R; Santhiago, V; Papoti, M; Gobatto, C A

2008-04-01

We assessed the responses of hematological parameters and their relationship to the anaerobic threshold of Brazilian soccer players during a training program. Twelve athletes were evaluated at the beginning (week 0, T1), in the middle (week 6, T2), and at the end (week 12, T3) of the soccer training program. On the first day at 7:30 am, before collecting the blood sample at rest for the determination of the hematological parameters, the athletes were conducted to the anthropometric evaluation. On the second day at 8:30 am, the athletes had their anaerobic threshold measured. Analysis of variance with Newman-Keuls'post hoc was used for statistical comparisons between the parameters measured during the soccer training program. Correlations between the parameters analyzed were determined using the Pearson's correlation coefficient. Erythrocytes concentration, hemoglobin, and hematocrit were significantly increased from T1 to T2. The specific soccer training program led to a rise in erythrocytes, hemoglobin, and hematocrit from T1 to T2. We assumed that these results occurred due to the plasma volume reduction and may be explained by the soccer training program characteristics. Furthermore, we did not observe any correlation between the anaerobic threshold and the hematological parameters.

A Study and Taxonomy of Vulnerabilities in Web Based Animation and Interactivity Software

DTIC Science & Technology

2010-12-01

Flash Player is available as a plugin for most common Web browsers (Firefox, Mozilla, Netscape, Opera) and as an ActiveX control for Internet...script or HTML via (1) a swf file that uses the asfunction: protocol or (2) the navigateToURL function when used with the Flash Player ActiveX ...malicious page or open a malicious file. 2. Coding an Exploit The specific flaw exists in the Flash Player ActiveX Control’s handling of the

Evolutionary dynamics of social dilemmas with asymmetry

NASA Astrophysics Data System (ADS)

Ma, Yongjuan; Chu, Chen; Chen, Fei; Shen, Chen; Geng, Yini; Shi, Lei

2018-04-01

Asymmetric phenomenon is ubiquitous in human and animal societies. Based on this fact, we construct an asymmetric way to investigate the evolution of cooperation. In detail, the structured populations are classified into two types: players of type A (strong player) possess higher fitness, while players of type B (weak player) possess fitness equaling their payoffs. Through numerical simulation, we find that our asymmetric setup can promote the evolution of cooperation, which is related to the leader role of the players of type A. It is worth mentioning that the larger the value of ω, namely, the degree of asymmetric becomes more large, the higher the level of cooperation. Besides, the higher degree of asymmetric will lead to a long relaxation time reaching stationary state and less striking promoting effect. Lastly, in order to test the robustness of mechanism, we explore the evolution of cooperation on different topologies.

Using an Interactive Computer Program to Communicate With the Wilderness Visitor

Treesearch

David W. Harmon

1992-01-01

The Bureau of Land Management, Oregon State Office, identified a need for a tool to communicate with wilderness visitors, managers, and decisionmakers regarding wilderness values and existing resource information in 87 wilderness study areas. An interactive computer program was developed using a portable Macintosh computer, a touch screen monitor, and laser disk player...

Youth Civic Engagement in China: Results from a Program Promoting Environmental Activism

ERIC Educational Resources Information Center

Johnson, Laura R.; Johnson-Pynn, Julie S.; Pynn, Thomas M.

2007-01-01

China is a key player on the global stage, and nearly 300 million Chinese youth stand to be affected by rapid social and ecological transformations. Programs that promote developmental assets in Chinese youth could increase their resilience in the face of contemporary stressors and enhance their capacity to contribute to China's development. In…

Got 'Em on a String: The Skills, Knowledge and Attributes of Group String Teachers in Queensland

ERIC Educational Resources Information Center

Ashton, Graham R.; Klopper, Christopher J.

2018-01-01

There appear to be considerable differences in the outcomes of group string teaching programs in Queensland. Some teachers appear to be able to generate, manage, and administrate highly efficacious programs; others seem to experience difficulty transferring the knowledge and skills required for students to become successful string players. As a…

simSchool: The Game of Teaching

ERIC Educational Resources Information Center

Zibit, Melanie; Gibson, David

2005-01-01

"simSchool" is a classroom simulation program funded by the Preparing Tomorrow's Teachers to Teach with Technology (PT3) program of the U.S. Department of Education. Just as a flight-simulator immerses a player in the complexities of flying a plane, "simSchool" immerses novice teachers in some of the complexities of teaching 7th-12th grade…

AMIC Cartilage Repair in a Professional Soccer Player

PubMed Central

Bark, S.; Riepenhof, H.; Gille, J.

2012-01-01

We report a case of a professional soccer player suffering from a traumatic cartilage lesion grade IV according to the Outerbridge classification at the femoral condyle treated with an enhanced microfracture technique (AMIC). Autologous Matrix-Induced Chondrogenesis (AMIC) is an innovative treatment for localized full-thickness cartilage defects combining the well-known microfracturing with collagen scaffold and fibrin glue. Because of the cartilage lesion (3 cm2), an AMIC procedure was performed followed by a rehabilitation program according to the protocols in the literature, (Steadman et al.; 2003). After 8 months of rehabilitation, the player returned to team training and after 10 months to competition. Altogether he returned to the same skill level for almost one year after the index operation. He is very satisfied with the clinical results after AMIC, which corresponds with the Lysholm score of 90 points at 12 months. PMID:23259120

Measurement of talent in volleyball: 15-month follow-up of elite adolescent players.

PubMed

Lidor, R; Hershko, Y; Bilkevitz, A; Arnon, M; Falk, B

2007-06-01

The purpose of this study was two-fold: first, to examine the contribution of a battery of physical and motor tests to early phases of talent detection and early development in volleyball, and second, to differentiate between and compare the motor ability of 16-year-old starter (S) and non-starter (NS) volleyball players. Fifteen male adolescent volleyball players underwent assessment of physical and motor ability 6 times during a 15-month training program; however, not all of them took part in each testing phase. The battery was composed of 8 physical and motor tests and 2 skill tests. The physical and motor tests included 2 speed tests, an agility run, 4 explosive power tests, and an endurance test. The skill tests evaluated service accuracy at rest and following effort. All participants improved their results in all but 2 tests (endurance and skill tests) across testing phases. Comparisons between the S (n=8) and NS (n=7) revealed that only one physical explosive power test (vertical jump with approach), was found to be a good indicator for distinguishing between the 2 groups of players. It was concluded that the volleyball battery of tests was not sensitive enough to distinguish between the ''good'' and ''very good'' players suggesting that physical and motor tests do not reflect open skill ability in volleyball.

Physical characteristics of elite adolescent female basketball players and their relationship to match performance

PubMed Central

Montalvo, Alicia; Latinjak, Alexander; Unnithan, Viswanath

2016-01-01

Abstract There were two aims of this study: first, to investigate physical fitness and match performance differences between under-16 (U16) and under-18 (U18) female basketball players, and second, to evaluate the relationship between physical fitness and game-related performances. Twenty-three young, female, elite Spanish basketball players (16.2 1.2 years) participated in the study. The sample was divided into two groups: U16 and U18 players. The average scores from pre- and post-season physical fitness measurements were used for subsequent analyses. Anthropometric variables were also measured. To evaluate game performance, game-related statistics, including the number of games and minutes played, points, rebounds, assists, steals and blocks per game, were recorded for every competitive match in one season. When anthropometric and physical performance variables were compared between groups, the U18 group demonstrated significantly (p<0.05) higher values in upper (+21.2%) and lower (+27.11%) limb strength compared to the U16 group. Furthermore, no significant differences between groups were observed in match performance outcomes. Only two performance variables, steals and assists per game, correlated significantly with jump capacity, speed, agility, anaerobic power, repeated sprint ability and aerobic power (p ≤ 0.005). These findings can help optimize training programs for young, elite female basketball players. PMID:28149421

The architecture of the chess player's brain.

PubMed

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

2014-09-01

The game of chess can be seen as a typical example for an expertise task requiring domain-specific training and experience. Despite intensive behavioural studies the neural underpinnings of chess performance and expertise are not entirely understood. A few functional neuroimaging studies have shown that expert chess players recruit different psychological functions and activate different brain areas while they are engaged in chess-related activities. Based on this functional literature, we predicted to find morphological differences in a network comprised by parietal and frontal areas and especially the occipito-temporal junction (OTJ), fusiform gyrus, and caudate nucleus. Twenty expert chess players and 20 control subjects were investigated using voxel-based and surface-based morphometry as well as diffusion tensor imaging. Grey matter volume and cortical thickness were reduced in chess players compared with those of control men in the OTJ and precunei. The volumes of both caudate nuclei were not different between groups, but correlated inversely with the years of chess playing experience. Mean diffusivity was increased in chess players compared with that of controls in the left superior longitudinal fasciculus and the Elo score (a chess tournament ranking) was inversely related to mean diffusivity within the right superior longitudinal fasciculus. To the best of our knowledge we showed for the first time that there are specific differences in grey and white matter morphology between chess players and control subjects in brain regions associated with cognitive functions important for playing chess. Whether these anatomical alterations are the cause or consequence of the intensive and long-term chess training and practice remains to be shown in future studies. Copyright © 2014 Elsevier Ltd. All rights reserved.

A cross-sport comparison of performance-based outcomes of professional athletes following primary microfracture of the knee.

PubMed

Schallmo, Michael S; Singh, Sameer K; Barth, Kathryn A; Freshman, Ryan D; Mai, Harry T; Hsu, Wellington K

2018-05-08

The purpose of this study was to compare performance-based outcomes among professional athletes in four major North American sports following microfracture to treat symptomatic chondral defects of the knee. Major League Baseball (MLB), National Basketball Association (NBA), National Football League (NFL), and National Hockey League (NHL) athletes who underwent primary unilateral microfracture of the knee were identified through a previously reported protocol based on public sources. Successful return-to-play was defined as returning for at least one professional regular season game after surgery. Regular season player statistics and sport-specific performance scores were compiled for each player. Each player served as his own control, with the season prior to surgery defined as baseline. Comparisons across sports were enabled by adjusting for expected season and career length differences between sports and by calculating percent changes in performance. One hundred thirty one professional athletes who underwent microfracture were included. One hundred three athletes (78.6%) successfully returned to play. The ratio of games started-to-games played before surgery was found to be a significant positive independent predictor of returning (p = 0.002). Compared with their preoperative season, basketball and baseball players demonstrated significantly decreased performance one season after surgery (-14.8%, p = 0.029 and -12.9%, p = 0.002, respectively) that was recoverable to baseline by postoperative seasons 2-3 for baseball players but not for basketball players (-9.7%, p = 0.024). Knee microfracture surgery is associated with a high rate of return to the professional level. However, the impact of this procedure on postoperative performance varied significantly depending on sport. Copyright © 2018. Published by Elsevier B.V.

Comparison of In-Season-Specific Resistance vs. A Regular Throwing Training Program on Throwing Velocity, Anthropometry, and Power Performance in Elite Handball Players.

PubMed

Hermassi, Souhail; van den Tillaar, Roland; Khlifa, Riadh; Chelly, Mohamed Souhaiel; Chamari, Karim

2015-08-01

The purpose of this study was to compare the effect of a specific resistance training program (throwing movement with a medicine ball) with that of regular training (throwing with regular balls) on ball velocity, anthropometry, maximal upper-body strength, and power. Thirty-four elite male team handball players (age: 18 ± 0.5 years, body mass: 80.6 ± 5.5 kg, height: 1.80 ± 5.1 m, body fat: 13.4 ± 0.6%) were randomly assigned to 1 of the 3 groups: control (n = 10), resistance training group (n = 12), or regular throwing training group (n = 12). Over the 8-week in season, the athletes performed 3 times per week according to an assigned training program alongside their normal team handball training. One repetition maximum (1RM) bench press and 1RM pullover scores assessed maximal arm strength. Anthropometry was assessed by body mass, fat percentage, and muscle volumes of upper body. Handball throwing velocity was measured by a standing throw, a throw with run, and a jump throw. Power was measured by measuring total distance thrown by a 3-kg medicine ball overhead throw. Throwing ball velocity, maximal strength, power, and muscle volume increases for the specific resistance training group after the 8 weeks of training, whereas only maximal strength, muscle volume and power and in the jump throw increases were found for the regular throwing training group. No significant changes for the control group were found. The current findings suggest that elite male handball players can improve ball velocity, anthropometrics, maximal upper-body strength, and power during the competition season by implementing a medicine ball throwing program.

Monitoring training load, recovery-stress state, immune-endocrine responses, and physical performance in elite female basketball players during a periodized training program.

PubMed

Nunes, João A; Moreira, Alexandre; Crewther, Blair T; Nosaka, Ken; Viveiros, Luis; Aoki, Marcelo S

2014-10-01

This study investigated the effect of a periodized training program on internal training load (ITL), recovery-stress state, immune-endocrine responses, and physical performance in 19 elite female basketball players. The participants were monitored across a 12-week period before an international championship, which included 2 overloading and tapering phases. The first overloading phase (fourth to sixth week) was followed by a 1-week tapering, and the second overloading phase (eighth to 10th week) was followed by a 2-week tapering. ITL (session rating of perceived exertion method) and recovery-stress state (RESTQ-76 Sport questionnaire) were assessed weekly and bi-weekly, respectively. Pretraining and posttraining assessments included measures of salivary IgA, testosterone and cortisol concentrations, strength, jumping power, running endurance, and agility. Internal training load increased across all weeks from 2 to 11 (p ≤ 0.05). After the first tapering period (week 7), a further increase in ITL was observed during the second overloading phase (p ≤ 0.05). After the second tapering period, a decrease in ITL was detected (p ≤ 0.05). A disturbance in athlete stress-recovery state was noted during the second overloading period (p ≤ 0.05), before returning to baseline level in end of the second tapering period. The training program led to significant improvements in the physical performance parameters evaluated. The salivary measures did not change despite the fluctuations in ITL. In conclusion, a periodized training program evoked changes in ITL in elite female basketball players, which appeared to influence their recovery-stress state. The training plan was effective in preparing participants for competition, as indicated by improvements in recovery-stress state and physical performance after tapering.

Low Cost SoC Design of H.264/AVC Decoder for Handheld Video Player

NASA Astrophysics Data System (ADS)

Wisayataksin, Sumek; Li, Dongju; Isshiki, Tsuyoshi; Kunieda, Hiroaki

We propose a low cost and stand-alone platform-based SoC for H.264/AVC decoder, whose target is practical mobile applications such as a handheld video player. Both low cost and stand-alone solutions are particularly emphasized. The SoC, consisting of RISC core and decoder core, has advantages in terms of flexibility, testability and various I/O interfaces. For decoder core design, the proposed H.264/AVC coprocessor in the SoC employs a new block pipelining scheme instead of a conventional macroblock or a hybrid one, which greatly contribute to reducing drastically the size of the core and its pipelining buffer. In addition, the decoder schedule is optimized to block level which is easy to be programmed. Actually, the core size is reduced to 138 KGate with 3.5 kbyte memory. In our practical development, a single external SDRAM is sufficient for both reference frame buffer and display buffer. Various peripheral interfaces such as a compact flash, a digital broadcast receiver and a LCD driver are also provided on a chip.

Prediction of hamstring injury in professional soccer players by isokinetic measurements

PubMed Central

Dauty, Marc; Menu, Pierre; Fouasson-Chailloux, Alban; Ferréol, Sophie; Dubois, Charles

2016-01-01

Summary Objectives previous studies investigating the ability of isokinetic strength ratios to predict hamstring injuries in soccer players have reported conflicting results. Hypothesis to determine if isokinetic ratios are able to predict hamstring injury occurring during the season in professional soccer players. Study Design case-control study; Level of evidence: 3. Methods from 2001 to 2011, 350 isokinetic tests were performed in 136 professional soccer players at the beginning of the soccer season. Fifty-seven players suffered hamstring injury during the season that followed the isokinetic tests. These players were compared with the 79 uninjured players. The bilateral concentric ratio (hamstring-to-hamstring), ipsilateral concentric ratio (hamstring-to-quadriceps), and mixed ratio (eccentric/concentric hamstring-to-quadriceps) were studied. The predictive ability of each ratio was established based on the likelihood ratio and post-test probability. Results the mixed ratio (30 eccentric/240 concentric hamstring-to-quadriceps) <0.8, ipsilateral ratio (180 concentric hamstring-to-quadriceps) <0.47, and bilateral ratio (60 concentric hamstring-to-hamstring) <0.85 were the most predictive of hamstring injury. The ipsilateral ratio <0.47 allowed prediction of the severity of the hamstring injury, and was also influenced by the length of time since administration of the isokinetic tests. Conclusion isokinetic ratios are useful for predicting the likelihood of hamstring injury in professional soccer players during the competitive season. PMID:27331039

Cognitive distortions, anxiety, and depression among regular and pathological gambling online poker players.

PubMed

Barrault, Servane; Varescon, Isabelle

2013-03-01

The aims were to assess cognitive distortions and psychological distress (anxiety and depression) among online poker players of different levels of gambling intensity (non-pathological gamblers [NPG], problem gamblers [PbG], and pathological gamblers [PG]), and to examine the relationship between these variables and gambling pathology. Overall, 245 regular online poker players recruited on an Internet forum completed online self-report scales assessing pathological gambling (South Oaks Gambling Screen [SOGS]), psychological distress (Hospital Anxiety and Depression Scale [HADS]) and cognitive distortions (Gambling-Related Cognition Scale). Based on their SOGS scores, poker players were ranked into three groups: NPG (n=146), PbG (n=55), and PG (n=44). All poker players appeared to be more anxious than depressive. PG exhibited higher levels of depression and anxiety than did PbG and NPG. Cognitive distortions also significantly discriminated PG from PbG and NPG. A regression model showed that the perceived inability to stop gambling, the illusion of control, depression (HADS D), and anxiety were good predictors for pathological gambling among poker players. Our results suggest that cognitive distortions play an important role in the development and maintenance of gambling pathology. This study also underlines the role of anxiety and depression in pathological gambling among poker players. It seems relevant to take these elements into account in the research, prevention, and treatment of pathological gambling poker players.

Every Player Wins in Recreational Sports.

ERIC Educational Resources Information Center

Fabian, Lou; And Others

1980-01-01

The use of recreational sports as a less competitive alternative to intramurals is described. The background for development of such a program at the University of Pittsburgh is presented, along with an outline of its benefits. (JMF)

INL Generic Robot Architecture

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

2005-03-30

The INL Generic Robot Architecture is a generic, extensible software framework that can be applied across a variety of different robot geometries, sensor suites and low-level proprietary control application programming interfaces (e.g. mobility, aria, aware, player, etc.).

Locomotor and Heart Rate Responses of Floaters During Small-Sided Games in Elite Soccer Players: Effect of Pitch Size and Inclusion of Goalkeepers.

PubMed

Lacome, Mathieu; Simpson, Ben M; Cholley, Yannick; Buchheit, Martin

2018-05-01

To (1) compare the locomotor and heart rate responses between floaters and regular players during both small and large small-sided games (SSGs) and (2) examine whether the type of game (ie, game simulation [GS] vs possession game [PO]) affects the magnitude of the difference between floaters and regular players. Data were collected in 41 players belonging to an elite French football team during 3 consecutive seasons (2014-2017). A 5-Hz global positionning system was used to collect all training data, with the Athletic Data Innovation analyzer (v5.4.1.514) used to derive total distance (m), high-speed distance (>14.4 km·h -1 , m), and external mechanical load (MechL, a.u.). All SSGs included exclusively 1 floater and were divided into 2 main categories, according to the participation of goalkeepers (GS) or not (PO) and then further divided into small and large (>100 m 2 per player) SSGs based on the area per player ratio. Locomotor activity and MechL performed were likely-to-most likely lower (moderate to large magnitude) in floaters compared with regular players, whereas differences in heart rate responses were unclear to possibly higher (small) in floaters. The magnitude of the difference in locomotor activity and MechL between floaters and regular players was substantially greater during GS compared with PO. Compared with regular players, floaters present decreased external load (both locomotor and MechL) despite unclear to possibly slightly higher heart rate responses during SSGs. Moreover, the responses of floaters compared with regular players are not consistent across different sizes of SSGs, with greater differences during GS than PO.

Energy Expenditure During Xbox Kinect Play in Early Adolescents: The Relationship with Player Mode and Game Enjoyment.

PubMed

Verhoeven, Katrien; Abeele, Vero Vanden; Gers, Brent; Seghers, Jan

2015-12-01

There has been growing interest in the use of active videogames to influence levels of physical activity. Most studies have investigated energy expenditure in general, without taking into account moderating factors such as player mode and game enjoyment. This study therefore examines whether children's energy expenditure and game enjoyment are higher when games are played in a two-player mode than in a single-player mode. Forty-three children from the 7th grade who exhibited an inactive lifestyle engaged in six sports exergames on an Xbox(®) Kinect(®) (Microsoft, Redmond, WA) console. The player mode (single-player or two-player mode) was manipulated (within-subjects design). The primary parameters were "energy expenditure," which was measured with a SenseWear(®) device (Bodymedia Inc., Pittsburgh, PA), and "game enjoyment," which was assessed through self-report. On average, Kinect play elicits moderate physical activity (approximately 4 metabolic equivalents of task). Games that are played in a two-player mode elicit more energy than games that are played in a single-player mode. However, this was only the case for simultaneous play (boxing, dancing, and tennis), not for turn-based play (bowling, baseball, and golf). Furthermore, participants generally liked exergaming, regardless of their sex or the player mode. Finally, no significant correlation was found between energy expenditure and game enjoyment. This study has shown that Kinect play elicits physical activity of moderate intensity. Furthermore, Kinect play is generally enjoyed by both boys and girls. Simultaneous play may be the best suited to increase levels of physical activity in early adolescents who exhibit an inactive lifestyle.

Positive Pedagogy for Sport Coaching

ERIC Educational Resources Information Center

Light, Richard L.; Harvey, Stephen

2017-01-01

The literature suggests that, despite some challenges in their implementation, player/athlete-centred, inquiry-based approaches to teaching games and coaching team sport can improve game playing ability, increase player/athlete motivation and provide positive affective experiences of learning. A range of these approaches, including Teaching Games…

Biomotor status and kinesiological education of girls aged 10 to 12 years--example: volleyball.

PubMed

Milić, Mirjana; Grgantov, Zoran; Katić, Ratko

2012-09-01

The aim of this study was to define processes of orientation and/or selection towards sports game of volleyball in schoolgirls of Kastela, aged 10-12, by examining the relations between regular classes of physical education (PE) and extracurricular sport activities. For this purpose, two morphological measures were used (body height and body mass) and a set of 11 motor tests (6 basic motor abilities tests and 5 motor achievement tests) on a sample of 242 girls aged 10-12 was used, divided into a subsample of 42 girls participating in volleyball training (Volleyball players) and a subsample of 200 girls who do not participate in volleyball training (volleyball non-players). Based on the comparison of test results of schoolgirls from Kastela and Croatian norms, factor analysis of applied variables and discriminant analysis of these variables between volleyball players and non-players, processes and/or phases of selection in forming quality volleyball players were defined. Selection processes are preceded by orientation processes in physical education classes, i.e. choosing those sport activities which are in accordance with the biomotor status of students. Results have shown that orientation and initial selection in female volleyball needs to be executed based on the motor set of psychomotor speed, repetitive strength of the trunk and flexibility (muscle tone regulation), and body height. Volleyball training has affected the muscle mass development and the development of strength factors, so that explosive strength of jumping and/or takeoff along with body height, has predominantly differentiated female volleyball players from non-players, aged 10 to 12, and serve and spike quality will have dominant influence on the match outcome.

Reduced severity of lumbo-pelvic-hip injuries in professional Rugby Union players following tailored preventative programmes.

PubMed

Evans, Kate L; Hughes, Jonathan; Williams, Morgan D

2018-03-01

The aim of this study was to tailor lumbo-pelvic-hip (LPH) injury reduction programmes in professional rugby union players based on screening data and examine its effectiveness. Prospective case controlled study. Twenty-eight professional rugby union players were screened pre- and immediately post- the YO-YO intermittent recovery level 1 test using six hip and groin strength tests (adductor squeeze at 0°, 60° and 90°, prone hip extension, abductor, adductor hand held dynamometry). The changes in hip and groin measures, were analysed using hierarchical cluster analysis. Three clusters emerged and a tailored LPH injury reduction programme was administered for each cluster. In addition, 22 players who were not involved in the initial testing received a generic LPH injury reduction programme and were used as the control. Seasonal information for LPH injury incidence, severity and prevalence were compared to the previous season. The same number of injuries were observed when the prospective injury surveillance data was compared to the previous season, however a reduced injury severity (936days vs 468days), average severity (78±126days vs 42±37days) and prevalence (21% vs 19%) were found. Moreover, LPH injury severity for players who were prescribed a tailored injury reduction programme (209days) were 50days less than players given a generic LPH injury reduction programme (259days). Our preliminary observations support the effectiveness of grouping players and tailoring intervention based on common group characteristics in reducing the severity of LPH injuries in professional Rugby Union. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

"Hand down, man down." Analysis of defensive adjustments in response to the hot hand in basketball using novel defense metrics.

PubMed

Csapo, Peter; Raab, Markus

2014-01-01

The hot-hand phenomenon, according to which a player's performance is significantly elevated during certain phases relative to the expected performance based on the player's base rate, has left many researchers and fans in basketball puzzled: The vast majority of players, coaches and fans believe in its existence but statistical evidence supporting this belief has been scarce. It has frequently been argued that the hot hand in basketball is unobservable because of strategic adjustments and defensive interference of the opposing team. We use a dataset with novel metrics, such as the number of defenders and the defensive intensity for each shot attempt, which enable us to directly measure defensive pressure. First, we examine how the shooting percentage of NBA players changes relative to the attributes of each metric. We find that it is of lesser importance by how many defenders a player is guarded but that defensive intensity, e.g., whether a defender raises his hand when his opponent shoots, has a larger impact on shot difficulty. Second, we explore how the underlying metrics and shooting accuracy change as a function of streak length. Our results indicate that defensive pressure and shot difficulty increase (decrease) during hot (cold) streaks, so that defenders seem to behave according to the hot-hand belief and try to force hot players into more difficult shots. However, we find that shooting percentages of presumably hot players do not increase and that shooting performance is not related to streakiness, so that the defenders' hot-hand behavior cannot be considered ecologically rational. Therefore, we are unable to find evidence in favor of the hot-hand effect even when accounting for defensive pressure.

Asymmetric Evolutionary Games

PubMed Central

McAvoy, Alex; Hauert, Christoph

2015-01-01

Evolutionary game theory is a powerful framework for studying evolution in populations of interacting individuals. A common assumption in evolutionary game theory is that interactions are symmetric, which means that the players are distinguished by only their strategies. In nature, however, the microscopic interactions between players are nearly always asymmetric due to environmental effects, differing baseline characteristics, and other possible sources of heterogeneity. To model these phenomena, we introduce into evolutionary game theory two broad classes of asymmetric interactions: ecological and genotypic. Ecological asymmetry results from variation in the environments of the players, while genotypic asymmetry is a consequence of the players having differing baseline genotypes. We develop a theory of these forms of asymmetry for games in structured populations and use the classical social dilemmas, the Prisoner’s Dilemma and the Snowdrift Game, for illustrations. Interestingly, asymmetric games reveal essential differences between models of genetic evolution based on reproduction and models of cultural evolution based on imitation that are not apparent in symmetric games. PMID:26308326

Cooperation driven by success-driven group formation

NASA Astrophysics Data System (ADS)

Szolnoki, Attila; Chen, Xiaojie

2016-10-01

In the traditional setup of the public goods game all players are involved in every available group and the mutual benefit is shared among competing cooperator and defector strategies. However, in real life situations the group formation of players could be more sophisticated because not all players are attractive enough for others to participate in a joint venture. What if only those players who are successful enough to the neighbors can initiate a group formation and establish a game? To elaborate this idea we employ a modified protocol and demonstrate that a carefully chosen threshold to establish a joint venture could efficiently improve the cooperation level even if the synergy factor would suggest a full defector state otherwise. The microscopic mechanism that is responsible for this effect is based on the asymmetric consequences of competing strategies: while the success of a cooperator provides a long-time well-being for the neighborhood, the temporary advantage of defection cannot be maintained if the protocol is based on the success of leaders.

Beyond Mechanism Design

NASA Technical Reports Server (NTRS)

Wolpert, David H.; Turner, Kagan

2004-01-01

The field of mechanism design is concerned with setting (incentives superimposed on) the utility functions of a group of players so as to induce desirable joint behavior of those players. It arose in the context of traditional equilibrium game theory applied to games involving human players. This has led it to have many implicit restrictions, which strongly limits its scope. In particular, it ignores many issues that are crucial for systems that are large (and therefore far off-equilibrium in general) and/or composed of non-human players (e.g., computer-based agents). This also means it has concentrated on issues that are often irrelevant in those broader domains (e.g., incentive compatibility). This paper illustrates these shortcomings by reviewing some of the recent theoretical work on the design of collectives, a body of work that constitutes a substantial broadening of mechanism design. It then presents computer experiments based on a recently suggested nanotechnology testbed that demonstrates the power of that extended version of mechanism design.

The Latarjet Procedure at the National Football League Scouting Combine: An Imaging and Performance Analysis.

PubMed

LeBus, George F; Chahla, Jorge; Sanchez, George; Akamefula, Ramesses; Moatshe, Gilbert; Phocas, Alexandra; Price, Mark D; Whalen, James M; LaPrade, Robert F; Provencher, Matthew T

2017-09-01

The Latarjet procedure is commonly performed in the setting of glenoid bone loss for treatment of recurrent anterior shoulder instability; however, little is known regarding the outcomes of this procedure in elite American football players. (1) Determine the prevalence, clinical features, and imaging findings of elite college football athletes who present to the National Football League (NFL) Combine with a previous Latarjet procedure and (2) describe these athletes' performance in the NFL in terms of draft status and initial playing time. Case series; Level of evidence, 4. After review of all football players who participated in the NFL Combine from 2009 to 2016, any player with a previous Latarjet procedure was included in this study. Medical records, position on the field, and draft position were recorded for each player. In addition, imaging studies were reviewed to determine fixation type, hardware complications, and status of the bone block. For those players who were ultimately drafted, performance was assessed based on games played and started, total snaps, and percentage of eligible snaps in which the player participated during his rookie season. Overall, 13 of 2617 (<1%) players at the combine were identified with a previous Latarjet procedure. Radiographically, 8 of 13 (61%) showed 2-screw fixation, while 5 of 13 (39%) had 1 screw. Of the 13 players, 6 (46%) players demonstrated hardware complications. All players had evidence of degenerative changes on plain radiographs, with 10 (77%) graded as mild, 1 (8%) as moderate, and 2 (15%) as severe according to the Samilson Prieto classification. Six of the 13 (46%) players went undrafted, while the remaining 7 (54%) were drafted; however, no player participated in more than half of the plays for which he was eligible during his rookie season. Only a small percentage of players at the NFL Combine (<1%) had undergone a Latarjet procedure. High rates of postoperative complications and radiographically confirmed degenerative change were observed. Athletes who had undergone a Latarjet procedure demonstrated a variable amount of playing time, but none participated in more than half of their eligible plays during their rookie season.

Lifetime prevalence of injuries in incoming division I collegiate football players.

PubMed

Sarac, Nikolas; Haynes, William; Pedroza, Angela; Kaeding, Christopher; Borchers, James

2017-11-01

The purpose of this study is to determine the lifetime prevalence of past injuries in incoming first year football players in a Division 1 college football team. Pre-participation questionnaires from 605 first-year football players over 20 years (1996-2015) were examined to determine the prevalence of concussions, stingers, fractures, and musculoskeletal surgeries sustained before playing at the collegiate level. Players were grouped by position: wide receiver and defensive back (WR/DB), offensive and defensive linemen (OL/DL), all other positions (OP), and unknown (UKN). Prevalence of injuries by year and position was compared using Pearson's χ 2 Test (p < 0.05). The reported lifetime prevalence is as follows: concussion (21%), stinger (23%), musculoskeletal surgery (23%), and fracture (44%). There were no significant differences in lifetime prevalence of concussions (p = 0.49), stingers (p = 0.31), fractures (p = 0.60), or musculoskeletal surgeries (p = 0.97) based on position. There were also no significant differences in the lifetime prevalence of concussions (p = 0.14), musculoskeletal surgeries (p = 0.50), or fractures (p = 0.59) based on year. However, there was a significant difference in the lifetime prevalence of stingers based on year (p < 0.001). There was an expectation to observe an increase in injury prevalence by entering year, but this was not seen. A decrease in stingers was actually observed, but there was no significant difference among any other injury recorded. These results do not support the perception that football injuries are on the rise. Under reporting is a significant concern as players may fear disqualification or that they are evaluated by the coaching staff based on their medical history. More research is needed to confirm lifetime injury prevalence and evaluate differences over time among football players.

The within-participant correlation between perception of effort and heart rate-based estimations of training load in elite soccer players.

PubMed

Kelly, David M; Strudwick, Anthony J; Atkinson, Greg; Drust, Barry; Gregson, Warren

2016-07-01

The measurement of relative physiological stress during training is important because this is the stimulus for the long-term adaptive response. Measurements of perceived exertion (RPE) have been reported to correlate with the heart rate during field-based training sessions. Nevertheless, there are few studies on how well RPE tracks with the heart rate over repeated training sessions in elite soccer players. Therefore, we aimed to quantify the within-participant correlations between variability in session-RPE (sRPE) and the heart rate in elite male soccer players, and to determine whether the playing position moderated these correlations. The field-based training of four central defenders, four wide defenders, six central midfielders, two wide midfielders and three attackers from an elite English Premier League squad were monitored over an entire in-season competitive period, giving a total of 1010 individual training sessions for study. Correlations between session-RPE and heart rates were quantified using a within-participant model. The correlation between changes in sRPE and heart rates was r = 0.75 (95% CI: 0.71-0.78). This correlation remained high across the various player positions (wide-defender, r = 0.81; central-defender, r = 0.74; wide midfielder, r = 0.70; central midfielder, r = 0.70; attacker, r = 0.84; P < 0.001). The correlation between changes in RPE and heart rates, measured during a season-long period of field-based training, is high in a sample of elite soccer players.

Collaboration between human and nonhuman players in Night Vision Tactical Trainer-Shadow

NASA Astrophysics Data System (ADS)

Berglie, Stephen T.; Gallogly, James J.

2016-05-01

The Night Vision Tactical Trainer - Shadow (NVTT-S) is a U.S. Army-developed training tool designed to improve critical Manned-Unmanned Teaming (MUMT) communication skills for payload operators in Unmanned Aerial Sensor (UAS) crews. The trainer is composed of several Government Off-The-Shelf (GOTS) simulation components and takes the trainee through a series of escalating engagements using tactically relevant, realistically complex, scenarios involving a variety of manned, unmanned, aerial, and ground-based assets. The trainee is the only human player in the game and he must collaborate, from his web-based mock operating station, with various non-human players via spoken natural language over simulated radio in order to execute the training missions successfully. Non-human players are modeled in two complementary layers - OneSAF provides basic background behaviors for entities while NVTT provides higher level models that control entity actions based on intent extracted from the trainee's spoken natural dialog with game entities. Dialog structure is modeled based on Army standards for communication and verbal protocols. This paper presents an architecture that integrates the U.S. Army's Night Vision Image Generator (NVIG), One Semi- Automated Forces (OneSAF), a flight dynamics model, as well as Commercial Off The Shelf (COTS) speech recognition and text to speech products to effect an environment with sufficient entity counts and fidelity to enable meaningful teaching and reinforcement of critical communication skills. It further demonstrates the model dynamics and synchronization mechanisms employed to execute purpose-built training scenarios, and to achieve ad-hoc collaboration on-the-fly between human and non-human players in the simulated environment.

A comparison of visual search strategies of elite and non-elite tennis players through cluster analysis.

PubMed

Murray, Nicholas P; Hunfalvay, Melissa

2017-02-01

Considerable research has documented that successful performance in interceptive tasks (such as return of serve in tennis) is based on the performers' capability to capture appropriate anticipatory information prior to the flight path of the approaching object. Athletes of higher skill tend to fixate on different locations in the playing environment prior to initiation of a skill than their lesser skilled counterparts. The purpose of this study was to examine visual search behaviour strategies of elite (world ranked) tennis players and non-ranked competitive tennis players (n = 43) utilising cluster analysis. The results of hierarchical (Ward's method) and nonhierarchical (k means) cluster analyses revealed three different clusters. The clustering method distinguished visual behaviour of high, middle-and low-ranked players. Specifically, high-ranked players demonstrated longer mean fixation duration and lower variation of visual search than middle-and low-ranked players. In conclusion, the results demonstrated that cluster analysis is a useful tool for detecting and analysing the areas of interest for use in experimental analysis of expertise and to distinguish visual search variables among participants'.

Selective altruism in collective games

NASA Astrophysics Data System (ADS)

Zappalà, Dario A.; Pluchino, Alessandro; Rapisarda, Andrea

2014-09-01

We study the emergence of altruistic behaviour in collective games. In particular, we take into account Toral's version of collective Parrondo's paradoxical games, in which the redistribution of capital between agents, who can play different strategies, creates a positive trend of increasing capital. In this framework, we insert two categories of players, altruistic and selfish ones, and see how they interact and how their capital evolves. More in detail, we analyse the positive effects of altruistic behaviour, but we also point out how selfish players take advantage of that situation. The general result is that altruistic behaviour is discouraged, because selfish players get richer while altruistic ones get poorer. We also consider a smarter way of being altruistic, based on reputation, called "selective altruism", which prevents selfish players from taking advantage of altruistic ones. In this new situation it is altruism, and not selfishness, to be encouraged and stabilized. Finally, we introduce a mechanism of imitation between players and study how it influences the composition of the population of both altruistic and selfish players as a function of time for different initial conditions and network topologies adopted.

The Dose-Response Relationship Between Training Load and Aerobic Fitness in Academy Rugby Union Players.

PubMed

Taylor, Richard J; Sanders, Dajo; Myers, Tony; Abt, Grant; Taylor, Celia A; Akubat, Ibrahim

2018-02-01

To identify the dose-response relationship between measures of training load (TL) and changes in aerobic fitness in academy rugby union players. Training data from 10 academy rugby union players were collected during a 6-wk in-season period. Participants completed a lactate-threshold test that was used to assess VO 2 max, velocity at VO 2 max, velocity at 2 mmol/L (lactate threshold), and velocity at 4 mmol/L (onset of lactate accumulation; vOBLA) as measures of aerobic fitness. Internal-TL measures calculated were Banister training impulse (bTRIMP), Edwards TRIMP, Lucia TRIMP, individualized TRIMP (iTRIMP), and session RPE (sRPE). External-TL measures calculated were total distance, PlayerLoad™, high-speed distance >15 km/h, very-high-speed distance >18 km/h, and individualized high-speed distance based on each player's vOBLA. A second-order-regression (quadratic) analysis found that bTRIMP (R 2  = .78, P = .005) explained 78% of the variance and iTRIMP (R 2  = .55, P = .063) explained 55% of the variance in changes in VO 2 max. All other HR-based internal-TL measures and sRPE explained less than 40% of variance with fitness changes. External TL explained less than 42% of variance with fitness changes. In rugby players, bTRIMP and iTRIMP display a curvilinear dose-response relationship with changes in maximal aerobic fitness.

A dual model of entertainment-based and community-based mechanisms to explore continued participation in online entertainment communities.

PubMed

Deng, Yun; Hou, Jinghui; Ma, Xiao; Cai, Shuqin

2013-05-01

Online entertainment communities have exploded in popularity and drawn attention from researchers. However, few studies have investigated what leads people to remain active in such communities at the postadoption stage. We proposed and tested a dual model of entertainment-based and community-based mechanisms to examine the factors that affect individuals' continued participation in online entertainment communities. Survival analysis was employed on a longitudinal dataset of 2,302 users collected over 2 years from an online game community. Our results were highly consistent with the theoretical model. Specifically, under the entertainment-based mechanism, our findings showed that the intensities of initial use and frequent use were positive predictors of players' activity lifespan. Under the community-based mechanism, the results demonstrated that the number of guilds a player was affiliated with and the average number of days of being a guild member positively predict players' lifespan in the game. Overall, our study suggests that the entertainment-based mechanism and community-based mechanism are two key drivers that determinate individuals' continued participation in online entertainment communities.

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 became 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. PMID:28708868

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

Using the Saliency-Based Model to Design a Digital Archaeological Game to Motivate Players' Intention to Visit the Digital Archives of Taiwan's Natural Science Museum

ERIC Educational Resources Information Center

Hong, Jon-Chao; Hwang, Ming-Yueh; Chen, Yu-Ju; Lin, Pei-Hsin; Huang, Yao-Tien; Cheng, Hao-Yueh; Lee, Chih-Chin

2013-01-01

Museums in Taiwan have developed various digital archives, but few people have visited these digital archives. Therefore, this study designed a digital archaeology game for high school students to play. Based on the concept of "learning for playing" (i.e., players who want to win will study more), the digital archaeology game contest…

Teaching water sustainability and STEM concepts using in-class, online, and real-world multiplayer simulations

NASA Astrophysics Data System (ADS)

Moysey, S. M.; Hannah, A. C.; Miller, S.; Mobley, C.

2013-12-01

Serious games are computer games with a primary purpose other than entertainment. Serious games are frequently used for training purposes, and can be used for educational and research purposes, increasing student interest and level of interaction as well as allowing researchers to collect data about emergent player behavior. The Naranpur Express simulation is based on a previously existing multiplayer role-playing game, where each player manages a small farm in rural India. Player goals include subsistence, upward economic mobility, and mitigation of environmental impact. Hydrologic and agricultural models are used to connect each player's small-scale decisions with their more far-reaching, and often difficult to perceive environmental impacts. This approach allows students to learn by discovery, experiencing first-hand the challenges of overuse of groundwater, fertilizers, and pesticides. Integration of new and rapidly developing social media techniques allows players to discuss solutions to their shared challenges, and help define a set of formal or informal rules governing their community. Previous versions of this game were implemented on paper, or in a spreadsheet run on each student's laptop. However, moving this simulation to an interactive online setting will allow us to study aggregate, as well as spatially varying effects of player decisions on economic and environmental outcomes. By coupling both physical and economic models with the real dynamics of player behavior, and considering the social and cultural aspects of agriculture, we can investigate the decision-making processes that control real environmental outcomes. By varying the types of information available to players, we can investigate how access to different kinds of information drives environmental decision-making. This can help identify key misunderstandings, thereby benefiting education and outreach efforts related to environmental justice and sustainability issues. Surveys collected from the students in a sophomore level course demonstrated that the use of the game positively enhanced student engagement and interest in the course. We adapted the same base concepts to a real-world setting where players must physically collect water from a contaminated surface water source, represented by a swimming pool where many players can access the resource simultaneously, and a clean groundwater source, represented by a barrel where only one player at a time can obtain water from a pump. Additionally, water is recharged to groundwater (i.e., the barrel) at a fixed rate, thus over pumping can cause the water table to drop and cause the well to go dry. Players must therefore grapple between health risks associated with contaminants and the mass balance problems caused by groundwater mining. This version of the game received positive reviews from girls in grades 6-9 participating in a STEM summer camp.

NUTRITIONAL INTAKE AND NUTRITIONAL STATUS IN ELITE MEXICAN TEENAGERS SOCCER PLAYERS OF DIFFERENT AGES.

PubMed

Hidalgo y Teran Elizondo, Roberto; Martín Bermudo, Francisco Manuel; Peñaloza Mendez, Ricardo; Berná Amorós, Genoveva; Lara Padilla, Eleazar; Berral de la Rosa, Francisco José

2015-10-01

nutritional intake and status of soccer players has attracted not much research attention. Many soccer players follow an inadequate nutritional intake and have a poor nutritional status. This is relevant in youngsters soccer players, in order to improve performance and promote healthy dietary practices. analyze anthropometric characterizes, evaluate nutritional intake and status, dietary habits and pre- and post-exercise meals in elite teenagers soccer players. seventy-two young male soccer players (15-20 years) from four junior teams of a soccer Club from the Mexican National Soccer League were measured for height, seat height, weight, 6 skinfolds, 6 diameters and 7 circumferences, height-for-age and BMI-for-age values. Skin, adipose, muscle, bone and residual tissue masses were calculated with the Ross and Kerr equation. Resting energy expenditure and intake was also measured. Daily dietary intake was self-recorded for 4 consecutive days (excluding the match day) using a digital food-weighing scale and a food record questionnaire. Dietary analysis was performed using the NutriBase 7 Clinical software. Several biochemical values were determined. One-way analysis of variance (ANOVA) and post hoc testing was performed using t-tests with a Bonferroni correction. all soccer players were within the normal range values for anthropometric parameters studies, when compared with other adolescent elite soccer teams. Values of plasma glucose, urea, creatinine, uric acid, lipid profile and total proteins were within normal range for young adult population, although albumin levels were high. Moreover, 14% and 20% of soccer players presented hyperuricemia and elevated total cholesterol levels respectively. Energy expenditure and intake were within normal range for all teenager elite soccer players. However, two teams shower significant lower intakes than demands. All macronutrient intakes were within recommendations, except protein that was higher. Micronutrient intake exceeded the recommendations for general population. Soccer players had pre- and post-exercise meals with an appropriate range of carbohydrates. Food intake was mainly based on cereals, derivatives and potatoes; meat, poultry, fish, shellfish and eggs and biscuits and confectionery and poor in fruit, vegetables and milk and dairy products. the population of soccer players did not have optimal nutritional habits. However, their nutritional intake and status was better than in other published studies. The main problems of these teams were that they had a high protein diet and that in some teams the nutritional intake was not enough to cover the demands. Finally, nutritional intake was found to be of poor quality. Thus, we recommend nutritional education for soccer players of these teams. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

A vision framework for the localization of soccer players and ball on the pitch using Handycams

NASA Astrophysics Data System (ADS)

Vilas, Tiago; Rodrigues, J. M. F.; Cardoso, P. J. S.; Silva, Bruno

2015-03-01

The current performance requirements in soccer make imperative the use of new technologies for game observation and analysis, such that detailed information about the teams' actions is provided. This paper summarizes a framework to collect the soccer players and ball positions using one or more Full HD Handycams, placed no more than 20cm apart in the stands, as well as how this framework connects to the FootData project. The system was based on four main modules: the detection and delimitation of the soccer pitch, the ball and the players detection and assignment to their teams, the tracking of players and ball and finally the computation of their localization (in meters) in the pitch.

Comparative analysis of gameplay and players emotion in the most popular games from play store

NASA Astrophysics Data System (ADS)

Riwinoto; Mahfud, N.; Lumombo, L.

2018-03-01

The development of the android mobile operating system and the presence of Play Store services poses challenges for developers to produce exciting mobile games. Although publishing games in Play Store is not difficult, in fact developers have to face tough competition to make homemade games can become popular. This study analyzes the gameplay of three popular paid-free games in Play Store that can survive for a period of one year from the top 10 positions in October 2015- November 2016. Analysis performed on 8 elements of the game based on the definition of Fullerton and emotional expression analysis of respondents who appeared while playing the three choosen games. The analysis shows that scarce resources are the main attraction of all three games because they create conflicts, giving constraints and challenges to players. The multiplayer game has a pattern of results and the result makes the opponent become more negative than the player to win. While the single player game is analyzed has a pattern to make the player get positive to win. There are 3 basic emotions that most often appear that is joy, disgust and surprise. Multiplayer games tend to emphasize the emotions of joy players, while single player games tend to bring disgust emotions.

Injuries in Australian school-level rugby union.

PubMed

Leung, Felix T; Franettovich Smith, Melinda M; Hides, Julie A

2017-11-01

There is a high incidence of injuries in rugby union due to the physical nature of the game. In youth rugby union, there are large variations in injury rates reported. Our study investigated the rates of injuries in school-level rugby union players in Australia using the consensus statement for rugby union injuries. Injury surveillance was conducted on 480 rugby players from 1 school in Queensland, Australia. Injury data were collected using paper-based injury recording forms during the 8-week rugby season using a "medical-attention" injury definition. In total, 76 players sustained one or more injuries, with a total of 80 injuries recorded. The overall injury rate was 31.8 injuries/1000 match player hours (95% CI, 25.4-39.4). Concussion had an incidence rate of 6.0/1000 match player hours (95% CI, 3.5-9.6). The incidence of upper limb and lower limb injuries were 9.1 and 9.9/1000 match player hours, respectively (95% CI, 5.9-13.5 and 6.6-14.5). The older age divisions had higher injury rates and most injuries occurred while tackling or being tackled. The injury rates observed in this sample of Australian school rugby union players provides direction for future studies to enable informed decisions relating to development of injury prevention programmes at this level of rugby.

Concussions during the 1997 Canadian Football League season.

PubMed

Delaney, J S; Lacroix, V J; Leclerc, S; Johnston, K M

2000-01-01

To examine the incidence and characteristics of concussions for one season in the Canadian Football League (CFL). Retrospective survey. 289 players reporting to CFL training camp. Of these, 154 players had played in the CFL during the 1997 season. Based on self-reported symptoms, calculations were made to determine the number of concussions experienced during the previous season, the duration of symptoms, the time for return to play after concussion, and any associated risk factors for concussions. Of all the athletes who played during the 1997 season, 44.8% experienced symptoms of a concussion. Only 18.8% of these concussed players recognized they had suffered a concussion. 69.6% of all concussed players experienced more than one episode. Symptoms lasted at least 1 day in 25.8% of cases. The odds of experiencing a concussion increased 13% with each game played. A past history of a loss of consciousness while playing football and a recognized concussion while playing football were both associated with increased odds of experiencing a concussion during the 1997 season. Many players experienced a concussion during the 1997 CFL season, but the majority of these players may not have recognized that fact. Players need to be better informed about the symptoms and effects of concussions.

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).

The Effect of Regular-Season Rest on Playoff Performance Among Players in the National Basketball Association

PubMed Central

Belk, John W.; Marshall, Hayden A.; McCarty, Eric C.; Kraeutler, Matthew J.

2017-01-01

Background: There has been speculation that rest during the regular season for players in the National Basketball Association (NBA) improves player performance in the postseason. Purpose: To determine whether there is a correlation between the amount of regular-season rest among NBA players and playoff performance and injury risk in the same season. Study Design: Cohort study; Level of evidence, 3. Methods: The Basketball Reference and Pro Sports Transactions archives were searched from the 2005 to 2015 seasons. Data were collected on players who missed fewer than 5 regular-season games because of rest (group A) and 5 to 9 regular-season games because of rest (group B) during each season. Inclusion criteria consisted of players who played a minimum of 20 minutes per game and made the playoffs that season. Players were excluded if they missed ≥10 games because of rest or suspension or missed ≥20 games in a season for any reason. Matched pairs were formed between the groups based on the following criteria: position, mean age at the start of the season within 2 years, regular-season minutes per game within 5 minutes, same playoff seeding, and player efficiency rating (PER) within 2 points. The following data from the playoffs were collected and compared between matched pairs at each position (point guard, shooting guard, forward/center): points per game, assists per game, PER, true shooting percentage, blocks, steals, and number of playoff games missed because of injury. Results: A total of 811 players met the inclusion and exclusion criteria (group A: n = 744 players; group B: n = 67 players). Among all eligible players, 27 matched pairs were formed. Within these matched pairs, players in group B missed significantly more regular-season games because of rest than players in group A (6.0 games vs 1.3 games, respectively; P < .0001). There were no significant differences between the groups at any position in terms of points per game, assists per game, PER, true shooting percentage, blocks, steals, or number of playoff games missed because of injury. Conclusion: Rest during the NBA regular season does not improve playoff performance or affect the injury risk during the playoffs in the same season. PMID:29051897

Alcohol management in community sports clubs: impact on viability and participation.

PubMed

Crundall, Ian

2012-08-01

Whether improved alcohol management delivers additional benefits to clubs in the form of financial viability, expanded membership, increased spectators and greater capacity for competition. Measures were derived from 657 Australian community sporting clubs enrolled in the Good Sports program. The program assists clubs to manage alcohol through an accreditation process that sets minimum standards for regulatory compliance, club practices and policies. Measures were taken from survey information collected prior to Level 1 accreditation and at the third and final level of club accreditation. Income was found to increase and reliance on alcohol as a funding source was found to diminish over time. Membership increased and was accelerated among females, young people and non-players. No changes in the number of junior and senior teams or players were found. Improved alcohol management can produce a range of benefits beyond responsible drinking patterns that add to club sustainability.

Effects of an off-season conditioning program on the physical characteristics of adolescent rugby union players.

PubMed

Smart, Daniel J; Gill, Nicholas D

2013-03-01

The aims of the study were to determine if a supervised off-season conditioning program enhanced gains in physical characteristics compared with the same program performed in an unsupervised manner and to establish the persistence of the physical changes after a 6-month unsupervised competition period. Forty-four provincial representative adolescent rugby union players (age, mean ± SD, 15.3 ± 1.3 years) participated in a 15-week off-season conditioning program either under supervision from an experienced strength and conditioning coach or unsupervised. Measures of body composition, strength, vertical jump, speed, and anaerobic and aerobic running performance were taken, before, immediately after, and 6 months after the conditioning. Post conditioning program the supervised group had greater improvements in all strength measures than the unsupervised group, with small, moderate and large differences between the groups\\x{2019} changes for chin-ups (9.1%; ± 11.6%), bench-press (16.9%; ± 11.7%) and box-squat (50.4%; ± 20.9%) estimated 1RM respectively. Both groups showed trivial increases in mass; however increases in fat free mass were small and trivial for supervised and unsupervised players respectively. Strength declined in the supervised group while the unsupervised group had small increases during the competition phase, resulting in only a small difference between the long-term changes in box-squat 1RM (15.9%; ± 13.2%). The supervised group had further small increases in fat free mass resulting in a small difference (2.4%; ± 2.7%) in the long-term changes. The postconditioning differences between the 2 groups may have been a result of increased adherence and the attainment of higher training loads during supervised training. The lack of differences in strength after the competition period indicates that supervision should be maintained to reduce substantial decrements in performance.

Active Player Modeling in the Iterated Prisoner's Dilemma

PubMed Central

Park, Hyunsoo; Kim, Kyung-Joong

2016-01-01

The iterated prisoner's dilemma (IPD) is well known within the domain of game theory. Although it is relatively simple, it can also elucidate important problems related to cooperation and trust. Generally, players can predict their opponents' actions when they are able to build a precise model of their behavior based on their game playing experience. However, it is difficult to make such predictions based on a limited number of games. The creation of a precise model requires the use of not only an appropriate learning algorithm and framework but also a good dataset. Active learning approaches have recently been introduced to machine learning communities. The approach can usually produce informative datasets with relatively little effort. Therefore, we have proposed an active modeling technique to predict the behavior of IPD players. The proposed method can model the opponent player's behavior while taking advantage of interactive game environments. This experiment used twelve representative types of players as opponents, and an observer used an active modeling algorithm to model these opponents. This observer actively collected data and modeled the opponent's behavior online. Most of our data showed that the observer was able to build, through direct actions, a more accurate model of an opponent's behavior than when the data were collected through random actions. PMID:26989405

Active Player Modeling in the Iterated Prisoner's Dilemma.

PubMed

Park, Hyunsoo; Kim, Kyung-Joong

2016-01-01

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

Differences in Cortical Representation and Structural Connectivity of Hands and Feet between Professional Handball Players and Ballet Dancers

PubMed Central

Meier, Jessica; Topka, Marlene Sofie; Hänggi, Jürgen

2016-01-01

It is known that intensive training and expertise are associated with functional and structural neuroadaptations. Most studies, however, compared experts with nonexperts; hence it is, specifically for sports, unclear whether the neuroplastic adaptations reported are sport-specific or sport-general. Here we aimed at investigating sport-specific adaptations in professional handball players and ballet dancers by focusing on the primary motor and somatosensory grey matter (GM) representation of hands and feet using voxel-based morphometry as well as on fractional anisotropy (FA) of the corticospinal tract by means of diffusion tensor imaging-based fibre tractography. As predicted, GM volume was increased in hand areas of handball players, whereas ballet dancers showed increased GM volume in foot areas. Compared to handball players, ballet dancers showed decreased FA in both fibres connecting the foot and hand areas, but they showed lower FA in fibres connecting the foot compared to their hand areas, whereas handball players showed lower FA in fibres connecting the hand compared to their foot areas. Our results suggest that structural adaptations are sport-specific and are manifested in brain regions associated with the neural processing of sport-specific skills. We believe this enriches the plasticity research in general and extends our knowledge of sport expertise in particular. PMID:27247805

Social Capital Accumulation in Location-Based Mobile Game Playing: A Multiple-Process Approach.

PubMed

Sung, Hei-Tung; Sigerson, Leif; Cheng, Cecilia

2017-08-01

In the summer of 2016, the widespread popularization of the game Pokémon Go brought the public's attention to the possible socialization benefits associated with location-based mobile games (LBMGs), yet no studies to date have investigated this issue. LBMGs deserve greater research attention because this type of game provides a unique gaming experience that encourages players to leave their homes and navigate around their neighborhood. This distinctive feature may promote more face-to-face interactions among LBMG players. Grounded in social capital theories, the present study compared the levels of both bridging and bonding social capital between LBMG and non-LBMG players. More important, we formulated a multiple-process model to explain the hypothesized psychological mechanisms underlying social capital accumulation among LBMG players. Participants were 349 U.S. participants (57 percent men; M age  = 32.40, SD age  = 7.92, age range = 19-66). Results supported the proposed model by revealing that face-to-face interaction was crucial to the accrual of both bridging and bonding social capital among LBMG players, through enhancing their levels of communication frequency and self-disclosure. The present findings have implications for the utilization of LBMG as a potential tool to promote face-to-face interactions and accumulate social capital.

Differences in Cortical Representation and Structural Connectivity of Hands and Feet between Professional Handball Players and Ballet Dancers.

PubMed

Meier, Jessica; Topka, Marlene Sofie; Hänggi, Jürgen

2016-01-01

It is known that intensive training and expertise are associated with functional and structural neuroadaptations. Most studies, however, compared experts with nonexperts; hence it is, specifically for sports, unclear whether the neuroplastic adaptations reported are sport-specific or sport-general. Here we aimed at investigating sport-specific adaptations in professional handball players and ballet dancers by focusing on the primary motor and somatosensory grey matter (GM) representation of hands and feet using voxel-based morphometry as well as on fractional anisotropy (FA) of the corticospinal tract by means of diffusion tensor imaging-based fibre tractography. As predicted, GM volume was increased in hand areas of handball players, whereas ballet dancers showed increased GM volume in foot areas. Compared to handball players, ballet dancers showed decreased FA in both fibres connecting the foot and hand areas, but they showed lower FA in fibres connecting the foot compared to their hand areas, whereas handball players showed lower FA in fibres connecting the hand compared to their foot areas. Our results suggest that structural adaptations are sport-specific and are manifested in brain regions associated with the neural processing of sport-specific skills. We believe this enriches the plasticity research in general and extends our knowledge of sport expertise in particular.

Validation of Field Methods to Assess Body Fat Percentage in Elite Youth Soccer Players.

PubMed

Munguia-Izquierdo, Diego; Suarez-Arrones, Luis; Di Salvo, Valter; Paredes-Hernandez, Victor; Alcazar, Julian; Ara, Ignacio; Kreider, Richard; Mendez-Villanueva, Alberto

2018-05-01

This study determined the most effective field method for quantifying body fat percentage in male elite youth soccer players and developed prediction equations based on anthropometric variables. Forty-four male elite-standard youth soccer players aged 16.3-18.0 years underwent body fat percentage assessments, including bioelectrical impedance analysis and the calculation of various skinfold-based prediction equations. Dual X-ray absorptiometry provided a criterion measure of body fat percentage. Correlation coefficients, bias, limits of agreement, and differences were used as validity measures, and regression analyses were used to develop soccer-specific prediction equations. The equations from Sarria et al. (1998) and Durnin & Rahaman (1967) reached very large correlations and the lowest biases, and they reached neither the practically worthwhile difference nor the substantial difference between methods. The new youth soccer-specific skinfold equation included a combination of triceps and supraspinale skinfolds. None of the practical methods compared in this study are adequate for estimating body fat percentage in male elite youth soccer players, except for the equations from Sarria et al. (1998) and Durnin & Rahaman (1967). The new youth soccer-specific equation calculated in this investigation is the only field method specifically developed and validated in elite male players, and it shows potentially good predictive power. © Georg Thieme Verlag KG Stuttgart · New York.

Effects of Resistance Training and Combined Training Program on Repeated Sprint Ability in Futsal Players.

PubMed

Torres-Torrelo, Julio; Rodríguez-Rosell, David; Mora-Custodio, Ricardo; Pareja-Blanco, Fernando; Yañez-García, Juan Manuel; González-Badillo, Juan José

2018-05-16

The purpose of this study was to compare the effects of 6 weeks resistance training (RT) with combined RT and loaded change of direction (CD) exercise on muscle strength and repeated sprint ability (RSA) in futsal players. Thirty-four players (age: 23.7±4.1 years; height: 1.77±0.06 m; body mass: 74.1±8.2 kg) were randomly assigned into three groups: full squat group (SG, n=12), combined full squat and CD group (S+CDG, n=12), and control group (CG, n=10). The RT for SG consisted of full squat with low-load (~45-60% 1RM) and low-volume (2-3 sets and 4-6 repetitions), whereas the S+CDG performed the same RT program combined with loaded CD (2-5 sets of 10 s). Estimated one-repetition maximum (1RM est ) and variables derived from RSA test including mean sprint time (RSA mean ), best sprint time (RSA best ), percent sprint decrement (S dec ), mean ground contact time (GCT mean ) and mean step length (SL) were selected as testing variables. Changes in sprint time and GCT in each sprint were also analysed. Both experimental groups showed significant (P<0.05-0.001) improvements for 1RM est , RSA best and first and second sprint time. In addition, S+CDG achieved significant (P<0.05-0.001) improvements in RSA mean, sprint time (from fifth to ninth sprint) and GCT (from third to eighth sprint). These results indicate that only 6 weeks of low-load and low-volume RT combined with CD in addition to routine futsal training is enough to improve RSA and strength performance simultaneously in futsal players. © Georg Thieme Verlag KG Stuttgart · New York.

Five-Day Whole-Body Cryostimulation, Blood Inflammatory Markers, and Performance in High-Ranking Professional Tennis Players

PubMed Central

Ziemann, Ewa; Olek, Robert Antoni; Kujach, Sylwester; Grzywacz, Tomasz; Antosiewicz, Jędrzej; Garsztka, Tomasz; Laskowski, Radosław

2012-01-01

Context Tournament season can provoke overreaching syndrome in professional tennis players, which may lead to deteriorated performance. Thus, appropriate recovery methods are crucial for athletes in order to sustain high-level performance and avoid injuries. We hypothesized that whole-body cryostimulation could be applied to support the recovery process. Objective To assess the effects of 5 days of whole-body cryostimulation combined with moderate-intensity training on immunologic, hormonal, and hematologic responses; resting metabolic rate; and tennis performance in a posttournament season. Design Controlled laboratory study. Setting National Olympic Sport Centre. Patients or Other Participants Twelve high-ranking professional tennis players. Intervention(s) Participants followed a moderate-intensity training program. A subgroup was treated with the 5-day whole-body cryostimulation (−120°C) applied twice a day. The control subgroup participated in the training only. Main Outcome Measure(s) Pretreatment and posttreatment blood samples were collected and analyzed for tumor necrosis factor α, interleukin 6, testosterone, cortisol, and creatine kinase. Resting metabolic rate and performance of a tennis drill were also assessed. Results Proinflammatory cytokine (tumor necrosis factor α) decreased and pleiotropic cytokine (interleukin 6) and cortisol increased in the group exposed to cryostimulation. In the same group, greater stroke effectiveness during the tennis drill and faster recovery were observed. Neither the training program nor cryostimulation affected resting metabolic rate. Conclusions Professional tennis players experienced an intensified inflammatory response after the completed tournament season, which may lead to overreaching. Applying whole-body cryostimulation in conjunction with moderate-intensity training was more effective for the recovery process than the training itself. The 5-day exposure to cryostimulation twice a day ameliorated the cytokine profile, resulting in a decrease in tumor necrosis factor α and an increase in interleukin 6. PMID:23182015

Examining Play Counts and Measurements of Injury Incidence in Youth Football.

PubMed

Kerr, Zachary Y; Yeargin, Susan W; Djoko, Aristarque; Dalton, Sara L; Baker, Melissa M; Dompier, Thomas P

2017-10-01

  Whereas researchers have provided estimates for the number of head impacts sustained within a youth football season, less is known about the number of plays across which such impact exposure occurs.   To estimate the number of plays in which youth football players participated during the 2013 season and to estimate injury incidence through play-based injury rates.   Descriptive epidemiology study.   Youth football.   Youth football players (N = 2098; age range, 5-15 years) from 105 teams in 12 recreational leagues across 6 states.   We calculated the average number of athlete-plays per season and per game using independent-samples t tests to compare age groups (5-10 years old versus 11-15 years old) and squad sizes (<20 versus ≥20 players); game injury rates per 1000 athlete-exposures (AEs) and per 10 000 athlete-plays; and injury rate ratios (IRRs) with 95% confidence intervals (CIs) to compare age groups.   On average, youth football players participated in 333.9 ± 178.5 plays per season and 43.9 ± 24.0 plays per game. Age groups (5- to 10-year-olds versus 11- to 15-year-olds) did not differ in the average number of plays per season (335.8 versus 332.3, respectively; t 2086.4 = 0.45, P = .65) or per game (44.1 versus 43.7, respectively; t 2092.3 = 0.38, P = .71). However, players from smaller teams participated in more plays per season (373.7 versus 308.0; t 1611.4 = 8.15, P < .001) and per game (47.7 versus 41.4; t 1523.5 = 5.67, P < .001). Older players had a greater game injury rate than younger players when injury rates were calculated per 1000 AEs (23.03 versus 17.86/1000 AEs; IRR = 1.29; 95% CI = 1.04, 1.60) or per 10 000 athlete-plays (5.30 versus 4.18/10 000 athlete-plays; IRR = 1.27; 95% CI = 1.02, 1.57).   A larger squad size was associated with a lower average number of plays per season and per game. Increasing youth football squad sizes may help reduce head-impact exposure for individual players. The AE-based injury rates yielded effect estimates similar to those of play-based injury rates.

The Effect of the "Zero Tolerance for Head Contact" Rule Change on the Risk of Concussions in Youth Ice Hockey Players.

PubMed

Krolikowski, Maciej P; Black, Amanda M; Palacios-Derflingher, Luz; Blake, Tracy A; Schneider, Kathryn J; Emery, Carolyn A

2017-02-01

Ice hockey is a popular winter sport in Canada. Concussions account for the greatest proportion of all injuries in youth ice hockey. In 2011, a policy change enforcing "zero tolerance for head contact" was implemented in all leagues in Canada. To determine if the risk of game-related concussions and more severe concussions (ie, resulting in >10 days of time loss) and the mechanisms of a concussion differed for Pee Wee class (ages 11-12 years) and Bantam class (ages 13-14 years) players after the 2011 "zero tolerance for head contact" policy change compared with players in similar divisions before the policy change. Cohort study; Level of evidence, 3. The retrospective cohort included Pee Wee (most elite 70%, 2007-2008; n = 891) and Bantam (most elite 30%, 2008-2009; n = 378) players before the rule change and Pee Wee (2011-2012; n = 588) and Bantam (2011-2012; n = 242) players in the same levels of play after the policy change. Suspected concussions were identified by a team designate and referred to a sport medicine physician for diagnosis. Incidence rate ratios (IRRs) were estimated based on multiple Poisson regression analysis, controlling for clustering by team and other important covariates and offset by game-exposure hours. Incidence rates based on the mechanisms of a concussion were estimated based on univariate Poisson regression analysis. The risk of game-related concussions increased after the head contact rule in Pee Wee (IRR, 1.85; 95% CI, 1.20-2.86) and Bantam (IRR, 2.48; 95% CI, 1.17-5.24) players. The risk of more severe concussions increased after the head contact rule in Pee Wee (IRR, 4.12; 95% CI, 2.00-8.50) and Bantam (IRR, 7.91; 95% CI, 3.13-19.94) players. The rates of concussions due to body checking and direct head contact increased after the rule change. The "zero tolerance for head contact" policy change did not reduce the risk of game-related concussions in Pee Wee or Bantam class ice hockey players. Increased concussion awareness and education after the policy change may have contributed to the increased risk of concussions found after the policy change.

The design and implementation of a randomized controlled trial of a risk reduction and human immunodeficiency virus prevention videogame intervention in minority adolescents: PlayForward: Elm City Stories.

PubMed

Fiellin, Lynn E; Kyriakides, Tassos C; Hieftje, Kimberly D; Pendergrass, Tyra M; Duncan, Lindsay R; Dziura, James D; Sawyer, Benjamin G; Fiellin, David A

2016-08-01

To address the need for risk behavior reduction and human immunodeficiency virus prevention interventions that capture adolescents "where they live," we created a tablet-based videogame to teach skills and knowledge and influence psychosocial antecedents for decreasing risk and preventing human immunodeficiency virus infection in minority youth in schools, after-school programs, and summer camps. We developed PlayForward: Elm City Stories over a 2-year period, working with researchers, commercial game designers, and staff and teens from community programs. The videogame PlayForward provides an interactive world where players, using an avatar, "travel" through time, facing challenges such as peer pressure to drink alcohol or engage in risky sexual behaviors. Players experience how their choices affect their future and then are able to go back in time and change their choices, creating different outcomes. A randomized controlled trial was designed to evaluate the efficacy of PlayForward. Participants were randomly assigned to play PlayForward or a set of attention/time control games on a tablet at their community-based program. Assessment data were collected during face-to-face study visits and entered into a web-based platform and unique real-time "in-game" PlayForward data were collected as players engaged in the game. The innovative methods of this randomized controlled trial are described. We highlight the logistical issues of conducting a large-scale trial using mobile technology such as the iPad(®), and collecting, transferring, and storing large amounts of in-game data. We outline the methods used to analyze the in-game data alone and in conjunction with standardized assessment data to establish correlations between behaviors during gameplay and those reported in real life. We also describe the use of the in-game data as a measure of fidelity to the intervention. In total, 333 boys and girls, aged 11-14 years, were randomized over a 14-month period: 166 were assigned to play PlayForward and 167 to play the control games. To date (as of 1 March 2016), 18 have withdrawn from the study; the following have completed the protocol-defined assessments: 6 weeks: 271 (83%), 3 months: 269 (84%), 6 months: 254 (79%), 12 months: 259 (82%), and 24 months: is ongoing with 152 having completed out of the 199 participants (76%) who were eligible to date (assessment windows were still open). Videogames can be developed to address complex behaviors and can be subject to empiric testing using community-based randomized controlled trials. Although mobile technologies pose challenges in their use as interventions and in the collection and storage of data they produce, they provide unique opportunities as new sources of potentially valid data and novel methods to measure the fidelity of digitally delivered behavioral interventions. © The Author(s) 2016.

The design and implementation of a randomized controlled trial of a risk reduction and human immunodeficiency virus prevention videogame intervention in minority adolescents: PlayForward: Elm City Stories

PubMed Central

Fiellin, Lynn E; Kyriakides, Tassos C; Hieftje, Kimberly D; Pendergrass, Tyra M; Duncan, Lindsay R; Dziura, James D; Sawyer, Benjamin G; Fiellin, David A

2016-01-01

Background To address the need for risk behavior reduction and HIV prevention interventions that capture adolescents “where they live,” we created a tablet-based videogame to teach skills and knowledge and influence psychosocial antecedents for decreasing risk and preventing HIV infection in minority youth in schools, after-school programs, and summer camps. Methods We developed PlayForward: Elm City Stories over a 2-year period, working with researchers, commercial game designers, and staff and teens from community programs. The videogame PlayForward provides an interactive world where players, using an avatar, “travel” through time, facing challenges such as peer pressure to drink alcohol or engage in risky sexual behaviors. Players experience how their choices affect their future and then are able to go back in time and change their choices, creating different outcomes. A randomized controlled trial was designed to evaluate the efficacy of PlayForward. Participants were randomly assigned to play PlayForward or a set of attention/time control games on a tablet at their community-based program. Assessment data were collected during face-to-face study visits and entered into a web-based platform and unique real-time “in-game” PlayForward data were collected as players engaged in the game. The innovative methods of this randomized controlled trial are described. We highlight the logistical issues of conducting a large-scale trial using mobile technology such as the iPad®, and collecting, transferring, and storing large amounts of in-game data. We outline the methods used to analyze the in-game data alone and in conjunction with standardized assessment data to establish correlations between behaviors during gameplay and those reported in real life. We also describe the use of the in-game data as a measure of fidelity to the intervention. Results In total, 333 boys and girls, aged 11–14 years, were randomized over a 14-month period: 166 were assigned to play PlayForward and 167 to play the control games. To date (as of 1 March 2016), 18 have withdrawn from the study; the following have completed the protocol-defined assessments: 6 weeks: 271 (83%); 3 months: 269 (84%); 6 months: 254 (79%); 12 months: 259 (82%); and 24 months: is ongoing with 152 having completed out of the 199 participants (76%) who were eligible to date (assessment windows were still open). Conclusion Videogames can be developed to address complex behaviors and can be subject to empiric testing using community-based randomized controlled trials. Although mobile technologies pose challenges in their use as interventions and in the collection and storage of data they produce, they provide unique opportunities as new sources of potentially valid data and novel methods to measure the fidelity of digitally delivered behavioral interventions. PMID:27013483

Comparison of Chosen Physical Fitness Characteristics of Turkish Professional Basketball Players by Division and Playing Position

PubMed Central

Köklü, Yusuf; Alemdaroğlu, Utku; Koçak, Fatma Ünver; Erol, A. Emre; Fındıkoğlu, Gülin

2011-01-01

The purpose of the present study was to compare chosen physical fitness characteristics of Turkish professional basketball players in different divisions (first and second division) and playing positions. Forty-five professional male basketball players (14 guards, 15 forwards, 16 centers) participated in this study voluntarily. For each player, anthropometric measurements were performed, as well as a multi-stage 20 m shuttle run, isokinetic leg strength, squat jump (SJ), countermovement jump (CMJ), 10–30 meter single-sprint and T-drill agility tests. The differences in terms of division were evaluated by independent t-test and the differences by playing position were evaluated by one-way ANOVA with Post Hoc Tukey test. First division players’ CMJ measurements were significantly higher than those of second division players’ (p≤0.05), whereas second division players’ 10 m sprint times were significantly better than those of first division players’ (p≤0.05). In addition, forwards and centers were significantly taller than guards. Centers were significantly heavier and their T-drill test performances were inferior to those of forwards and guards (p≤0.05). Moreover, guards had a significantly higher maximal oxygen uptake (VO2 max) than centers. Guards and forwards showed significantly better performance in the 10 and 30 m sprint tests than centers (p≤0.05). Forwards and centers had significantly better left leg flexor strength at 180°.s−1(p≤0.05). In conclusion, the findings of the present study indicated that physical performance of professional basketball players differed among guards, forwards and centers, whereas there were not significant differences between first and second division players. According to the present study, court positions have different demands and physical attributes which are specific to each playing position in professional basketball players. Therefore, these results suggest that coaches should tailor fitness programs according to specific positions on the court. PMID:23486863

A Small Taste of Big Data: Strategies for Evaluating Reach, Impact, and Outcomes of Starchitect on Facebook

NASA Astrophysics Data System (ADS)

Harold, J. B.

2015-12-01

Starchitect (www.starchitect.net) is an online stellar and planetary evolution game developed for Facebook (though it can be played outside of Facebook as well). Funded through NASA and NSF, Starchitect was designed in part to explore the educational potential of a specific type of game design, in which players may only spend a few minutes with the game in a given sitting, but must come back repeatedly over days or weeks to make real progress. The intent was to determine if we could engage players and keep them "minds on" for longer periods of time, enhancing the educational value of the game. However this design leads to a variety of challenges and opportunities for the evaluation program. Players cannot easily be asked to "play through" the game while under observation, because the game is designed to be played over long periods. Even recruiting test players can be a challenge, since this particular game framework doesn't appeal to everyone, and we need players to stay engaged long enough to have a meaningful experience. On the other hand, the game itself collects large amounts of data automatically, and can be strategically designed to collect even more. N in this case is very large (in excess of 11,000 players to date), and Facebook enhances the data by providing information about players that is not generally available to online activities (e.g., gender and age). All told this provides us with an intriguing double edged sword: challenges for traditional, in-person evaluation strategies, combined with new opportunities for online recruitment and automated data collection. This paper will discuss the strategies we've used to evaluate the project, including interviews, online surveys dynamically triggered by the game, targeted Facebook advertising, game data evaluation, embedded pre/post quizzes, and more.

Sensorimotor Control of the Shoulder in Professional Volleyball Players with Isolated Infraspinatus Muscle Atrophy.

PubMed

Contemori, Samuele; Biscarini, Andrea; Botti, Fabio Massimo; Busti, Daniele; Panichi, Roberto; Pettorossi, Vito Enrico

2017-06-12

Isolated infraspinatus muscle atrophy (IIMA) only affects the hitting shoulder of overhead-activity athletes, and is caused by suprascapular nerve neuropathy. No study has assessed the static and dynamic stability of the shoulder in overhead professional athletes with IIMA to reveal possible shoulder sensorimotor alterations. To assess the shoulder static stability, dynamic stability, and strength in professional volleyball players with IIMA and in healthy control players. Cross-sectional study. Research laboratory. Twenty-four male professional volleyball players (12 players with diagnosed IIMA and 12 healthy players) recruited from local volleyball teams. Static stability was evaluated with two independent force platforms and dynamic stability was assessed with the "Upper Quarter Y Balance Test". The static stability assessment was conducted in different support (single hand and both hand) and vision (open and closed eyes) conditions. Data from each test were analyzed with ANOVA and paired t-test models, to highlight statistical differences within and between groups. In addition to reduced abduction and external rotation strength, athletes with IIMA consistently demonstrated significant less static (P < 0.001) and dynamic stability (P < 0,001), compared with the contralateral shoulder and with healthy athletes. Closed eyes condition significantly enhanced the static stability deficit of the shoulder with IIMA (P = 0.039 and P = 0.034 for both hand and single hand support, respectively), but had no effect in healthy contralateral and healthy players' shoulders. This study highlights an impairment of the sensorimotor control system of the shoulder with IIMA, which likely results from both proprioceptive and strength deficits. This condition could yield subtle alteration in the functional use of the shoulder and predispose it to acute or overuse injuries. The results of this study may help athletic trainers and physical/physiotherapists to prevent shoulder injuries and create specific proprioceptive and neuromuscular training programs.

Low External Workloads Are Related to Higher Injury Risk in Professional Male Basketball Games

PubMed Central

Caparrós, Toni; Casals, Martí; Solana, Álvaro; Peña, Javier

2018-01-01

The primary purpose of this study was to identify potential risk factors for sports injuries in professional basketball. An observational retrospective cohort study involving a male professional basketball team, using game tracking data was conducted during three consecutive seasons. Thirty-three professional basketball players took part in this study. A total of 29 time-loss injuries were recorded during regular season games, accounting for 244 total missed games with a mean of 16.26 ± 15.21 per player and season. The tracking data included the following variables: minutes played, physiological load, physiological intensity, mechanical load, mechanical intensity, distance covered, walking maximal speed, maximal speed, sprinting maximal speed, maximal speed, average offensive speed, average defensive speed, level one acceleration, level two acceleration, level three acceleration, level four acceleration, level one deceleration, level two deceleration, level three deceleration, level four deceleration, player efficiency rating and usage percentage. The influence of demographic characteristics, tracking data and performance factors on the risk of injury was investigated using multivariate analysis with their incidence rate ratios (IRRs). Athletes with less or equal than 3 decelerations per game (IRR, 4.36; 95% CI, 1.78-10.6) and those running less or equal than 1.3 miles per game (lower workload) (IRR, 6.42 ; 95% CI, 2.52-16.3) had a higher risk of injury during games (p < 0.01 in both cases). Therefore, unloaded players have a higher risk of injury. Adequate management of training loads might be a relevant factor to reduce the likelihood of injury according to individual profiles. Key points The number of decelerations and the total distance can be considered risk factors for injuries in professional basketball players. Unloaded players have greater risk of injury compared to players with higher accumulated external workload. Workload management should be considered a major factor in injury prevention programs. PMID:29769830

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 larger samples with more injured cases is warranted to further ascertain the importance of this risk factor.

Association Between Playing American Football in the National Football League and Long-term Mortality.

PubMed

Venkataramani, Atheendar S; Gandhavadi, Maheer; Jena, Anupam B

2018-02-27

Studies of the longevity of professional American football players have demonstrated lower mortality relative to the general population but they may have been susceptible to selection bias. To examine the association between career participation in professional American football and mortality risk in retirement. Retrospective cohort study involving 3812 retired US National Football League (NFL) players who debuted in the NFL between 1982 and 1992, including regular NFL players (n = 2933) and NFL "replacement players" (n = 879) who were temporarily hired to play during a 3-game league-wide player strike in 1987. Follow-up ended on December 31, 2016. NFL participation as a career player or as a replacement player. The primary outcome was all-cause mortality by December 31, 2016. Cox proportional hazards models were estimated to compare the observed number of years from age 22 years until death (or censoring), adjusted for birth year, body mass index, height, and position played. Information on player death and cause of death was ascertained from a search of the National Death Index and web-based sources. Of the 3812 men included in this study (mean [SD] age at first NFL activity, 23.4 [1.5] years), there were 2933 career NFL players (median NFL tenure, 5 seasons [interquartile range {IQR}, 2-8]; median follow-up, 30 years [IQR, 27-33]) and 879 replacement players (median NFL tenure, 1 season [IQR, 1-1]; median follow-up, 31 years [IQR, 30-33]). At the end of follow-up, 144 NFL players (4.9%) and 37 replacement players (4.2%) were deceased (adjusted absolute risk difference, 1.0% [95% CI, -0.7% to 2.7%]; P = .25). The adjusted mortality hazard ratio for NFL players relative to replacements was 1.38 (95% CI, 0.95 to 1.99; P = .09). Among career NFL players, the most common causes of death were cardiometabolic disease (n = 51; 35.4%), transportation injuries (n = 20; 13.9%), unintentional injuries (n = 15; 10.4%), and neoplasms (n = 15; 10.4%). Among NFL replacement players, the leading causes of death were cardiometabolic diseases (n = 19; 51.4%), self-harm and interpersonal violence (n = 5; 13.5%), and neoplasms (n = 4; 10.8%). Among NFL football players who began their careers between 1982 and 1992, career participation in the NFL, compared with limited NFL exposure obtained primarily as an NFL replacement player during a league-wide strike, was not associated with a statistically significant difference in long-term all-cause mortality. Given the small number of events, analysis of longer periods of follow-up may be informative.

Child Care Funding Sources for California School Districts. CRB 08-014

ERIC Educational Resources Information Center

Foster, Lisa K.

2008-01-01

School districts are central players in the child care delivery system: they operate a mix of child care centers and programs, serve a range of children of different ages, and fund their programs from a variety of federal, state, and local sources. This report provides a range of programmatic and fiscal information about the federal and state…

Physical and Physiological Demands of Experienced Male Basketball Players During a Competitive Game.

PubMed

Puente, Carlos; Abián-Vicén, Javier; Areces, Francisco; López, Roberto; Del Coso, Juan

2017-04-01

Puente, C, Abián-Vicén, J, Areces, F, López, R, and Del Coso, J. Physical and physiological demands of experienced male basketball players during a competitive game. J Strength Cond Res 31(4): 956-962, 2017-The aim of this investigation was to analyze the physical and physiological demands of experienced basketball players during a real and competitive game. Twenty-five well-trained basketball players (8 guards, 8 forwards, and 9 centers) played a competitive game on an outdoor court. Instantaneous running speeds, the number of body impacts above 5 g, and the number of accelerations and decelerations were assessed by means of a 15-Hz global Positioning System accelerometer unit. Individual heart rate was also recorded using heart rate monitors. As a group mean, the basketball players covered 82.6 ± 7.8 m·min during the game with a mean heart rate of 89.8 ± 4.4% of maximal heart rate. Players covered 3 ± 3% of the total distance running at above 18 km·h and performed 0.17 ± 0.13 sprints per minute. The number of body impacts was 8.2 ± 1.8 per minute of play. The running pace of forwards was higher than that of centers (86.8 ± 6.2 vs. 76.6 ± 6.0 m·min; p ≤ 0.05). The maximal speed obtained during the game was significantly higher for guards than that for centers (24.0 ± 1.6 km·h vs. 21.3 ± 1.6 km·h; p ≤ 0.05). Centers performed a lower number of accelerations/decelerations than guards and forwards (p ≤ 0.05). In conclusion, the extraordinary rates of specific movements performed by these experienced basketball players indicate the high physiological demands necessary to be able to compete in this sport. The centers were the basketball players who showed lower physiological demands during a game, whereas there were no differences between guards and forwards. These results can be used by coaches to adapt basketball training programs to the specific demands of each playing position.

Effects of Ramadan Fasting on Body Composition, Aerobic Performance and Lactate, Heart Rate and Perceptual Responses in Young Soccer Players

PubMed Central

Güvenç, Alpay

2011-01-01

The purpose of this study was to examine the effects of Ramadan fasting on body composition, aerobic exercise performance and blood lactate, heart rate and perceived exertion in regularly trained young soccer players. Sixteen male soccer players participated in this study. Mean age, stature, body mass and training age of the players were 17.4±1.2 years, 175.4±3.6 cm, 69.6±4.3 kg and 5.1±1.3 years, respectively. During the Ramadan period, all subjects voluntarily chose to follow the fasting guidelines and abstained from eating and drinking from sunrise to sunset. Body composition, hydration status, dietary intake and sleep duration were assessed on four occasions: before Ramadan, at the beginning of Ramadan, at the end of Ramadan and 2 weeks after the end of Ramadan. On each occasion, aerobic exercise performance and blood lactate, heart rate and rating of perceived exertion responses of players were also determined during an incremental running test. Repeated measures of ANOVA revealed that body mass, percentage of body fat, fat-free mass, hydration status, daily sleeping time and daily energy and macronutrient intake of players did not vary significantly throughout the study period (p>0.05). However, players experienced a small but significant decrease in skinfold thicknesses over the course of the study (p<0.05). Although ratings of perceived exertion at submaximal workloads increased during Ramadan (p<0.05), blood lactate and heart rate responses had decreased by the end of Ramadan (p<0.05). In line with these changes, peak running performance and running velocity at anaerobic threshold also improved by the end of Ramadan (p<0.05). Improvements in aerobic exercise performance with time were probably due to the effects of pre-season training program that was performed after the break of the fast (Iftar) during the month of Ramadan. The results of the present study suggest that if regular training regimen, body fluid balance, daily energy intake and sleep duration are maintained as before Ramadan, Ramadan fasting does not have detrimental effects on aerobic exercise performance or body composition in young soccer players. PMID:23486092

Effects of ramadan fasting on body composition, aerobic performance and lactate, heart rate and perceptual responses in young soccer players.

PubMed

Güvenç, Alpay

2011-09-01

The purpose of this study was to examine the effects of Ramadan fasting on body composition, aerobic exercise performance and blood lactate, heart rate and perceived exertion in regularly trained young soccer players. Sixteen male soccer players participated in this study. Mean age, stature, body mass and training age of the players were 17.4±1.2 years, 175.4±3.6 cm, 69.6±4.3 kg and 5.1±1.3 years, respectively. During the Ramadan period, all subjects voluntarily chose to follow the fasting guidelines and abstained from eating and drinking from sunrise to sunset. Body composition, hydration status, dietary intake and sleep duration were assessed on four occasions: before Ramadan, at the beginning of Ramadan, at the end of Ramadan and 2 weeks after the end of Ramadan. On each occasion, aerobic exercise performance and blood lactate, heart rate and rating of perceived exertion responses of players were also determined during an incremental running test. Repeated measures of ANOVA revealed that body mass, percentage of body fat, fat-free mass, hydration status, daily sleeping time and daily energy and macronutrient intake of players did not vary significantly throughout the study period (p>0.05). However, players experienced a small but significant decrease in skinfold thicknesses over the course of the study (p<0.05). Although ratings of perceived exertion at submaximal workloads increased during Ramadan (p<0.05), blood lactate and heart rate responses had decreased by the end of Ramadan (p<0.05). In line with these changes, peak running performance and running velocity at anaerobic threshold also improved by the end of Ramadan (p<0.05). Improvements in aerobic exercise performance with time were probably due to the effects of pre-season training program that was performed after the break of the fast (Iftar) during the month of Ramadan. The results of the present study suggest that if regular training regimen, body fluid balance, daily energy intake and sleep duration are maintained as before Ramadan, Ramadan fasting does not have detrimental effects on aerobic exercise performance or body composition in young soccer players.

Resident-Assisted Montessori Programming (RAMP): training persons with dementia to serve as group activity leaders.

PubMed

Camp, Cameron J; Skrajner, Michael J

2004-06-01

The purpose of this study was to determine the effects of an activity implemented by means of Resident-Assisted Montessori Programming (RAMP). Four persons with early-stage dementia were trained to serve as leaders for a small-group activity played by nine persons with more advanced dementia. Assessments of leaders' ability to learn the procedures of leading a group, as well as their satisfaction with this role, were taken, as were measures of players' engagement and affect during standard activities programming and RAMP activities. Leaders demonstrated the potential to fill the role of group activity leader effectively, and they expressed a high level of satisfaction with this role. Players' levels of positive engagement and pleasure during the RAMP activity were higher than during standard group activities. This study suggests that to the extent that procedural learning is available to persons with early-stage dementia, especially when they are assisted with external cueing, these individuals can successfully fill the role of volunteers when working with persons with more advanced dementia. This can provide a meaningful social role for leaders and increase access to high quality activities programming for large numbers of persons with dementia. Copyright 2004 The Gerontological Society of America

The Multi-Player Performance-Enhancing Drug Game

PubMed Central

Haugen, Kjetil K.; Nepusz, Tamás; Petróczi, Andrea

2013-01-01

This paper extends classical work on economics of doping into a multi-player game setting. Apart from being among the first papers formally formulating and analysing a multi-player doping situation, we find interesting results related to different types of Nash-equilibria (NE). Based mainly on analytic results, we claim at least two different NE structures linked to the choice of prize functions. Linear prize functions provide NEs characterised by either everyone or nobody taking drugs, while non-linear prize functions lead to qualitatively different NEs with significantly more complex predictive characteristics. PMID:23691018

Video Game-Based Learning: An Emerging Paradigm for Instruction

ERIC Educational Resources Information Center

Squire, Kurt D.

2008-01-01

Interactive digital media, or video games, are a powerful new medium. They offer immersive experiences in which players solve problems. Players learn more than just facts--ways of seeing and understanding problems so that they "become" different kinds of people. "Serious games" coming from business strategy, advergaming, and entertainment gaming…

Meeting Challenges of the '90s.

ERIC Educational Resources Information Center

Smith, Jamie

1993-01-01

Describes three new technological devices and possible educational applications: (1) Canon's Xapshot Camera that records photographs as digitized information on disk to be viewed on television, videotapes, or computers; (2) Kodak's Photo CD Player, that stores photographs to be viewed on a CD player; and (3) Apple's Pen-Based Pocket Computer. (LRW)

Video Game-Based Learning: An Emerging Paradigm for Instruction

ERIC Educational Resources Information Center

Squire, Kurt D.

2013-01-01

Interactive digital media, or video games, are a powerful new medium. They offer immersive experiences in which players solve problems. Players learn more than just facts--ways of seeing and understanding problems so that they "become" different kinds of people. "Serious games" coming from business strategy, advergaming, and entertainment gaming…