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Sample records for hockey player considerations

  1. Swimming literacy field hockey woman player ground.

    Baštová, Miroslava

    2012-01-01

    Title: Swimming literacy field hockey woman player ground. Objectives: To obtain and analyze data on the level ground swimming literacy field hockey woman player. Their perception swimming literacy for life, the use of non-specific regeneration and as a training resource. Methods: Analysis of scientific literature, survey, case study, data analysis and graphical presentation of results. Results of the work: field hockey player as swimming literate, benefits swimming but not used as a means of...

  2. Body composition of italian female hockey players

    P Pavan

    2009-07-01

    Full Text Available Objective: In this work the anthropometric features and the body composition of Italian hockey players, members of the Female National team, were analysed. The purpose of the research was to verify if morphological features could influence the performance of different positional groups. Materials and Methods: Each player was measured for her total and sitting height, weight, 9 skinfolds thickness and bioelectrical impedance analysis. Different equations were used to calculate the Fat% from skinfolds thickness. Results: Average height is not a crucial advantage for this sport. On the contrary the proportion trunk-limb seems to play an important role for the performance of the midfield players. Percentage of body fat of the hockey players was lower than the Fat% of the non-athletes women of the same age. Significant differences were found between Fat% determined by skinfolds thickness and Fat% obtained by bioelectrical impedance analysis. Conclusions: The results of this study indicate that there are significant differences in anthropometric features and in body composition between positional groups, stressing the importance of a specific training program. Keywords: field hockey, bioelectrical impedance, skinfolds thickness, anthropometry.

  3. Incidence of Concussion in Youth Ice Hockey Players.

    Kontos, Anthony P; Elbin, R J; Sufrinko, Alicia; Dakan, Scott; Bookwalter, Kylie; Price, Ali; Meehan, William P; Collins, Michael W

    2016-02-01

    Ice hockey is a fast-paced collision sport that entails both intentional (ie, body checking) and incidental contact that may involve the head. The objective of this study was to determine the incidence of concussions in relation to games/practices and age among competition-level youth ice hockey players (ages 12-18 years). Participants included 397 youth ice hockey players from Western Pennsylvania; Boston, Massachusetts; and Birmingham, Alabama, during the 2012-2013 and 2013-2014 youth ice hockey seasons. Incidence rates (IRs) and incidence rate ratios (IRRs) of concussion were calculated for games/practices and age groups. A total of 23 369 (12 784 practice/10 585 game) athletic exposures (AEs) involving 37 medically diagnosed concussions occurred. More than 40% of concussions involved illegal contact. The combined IR for games and practices was 1.58 concussions per 1000 AEs. The IRR was 2.86 times (95% confidence interval 0.68-4.42) higher during games (2.49 per 1000 AEs) than practices (1.04 per 1000 AEs). The overall IR for concussion in youth ice hockey was comparable to those reported in other youth collision sports. The game-to-practice IRR was lower than previously reported in ice hockey and other youth sports, although more concussions per exposure occurred in games compared with practices. Younger players had a higher rate of concussions than older players. Copyright © 2016 by the American Academy of Pediatrics.

  4. An intelligent talent recognition of male youth field hockey players ...

    The aim of this study was to determine the most significant of physical fitness, anthro-energy intake and psychological variables in identifying the talented male youth field hockey players. 40 male players (age, 14.6 ± 1.2 years) from Terengganu sport academy were evaluated in different tests and measurements.

  5. Spinal mobility and trunk muscle strength in elite hockey players.

    Lindgren, S; Twomey, L

    1988-01-01

    Elite hockey players of both sexes from the Australian Institute of Sport were assessed for lumbar spine mobility, trunk flexion and back extensor muscle strength, hamstring flexibility and postural characteristics over a two year period. All the athletes were more mobile in rotation than the 'normal' West Australian population, and demonstrated flexible hamstrings and powerful back extensor muscles; trunk flexion was less strong initially, but improved after intervention in the form of a specific exercise programme, over the measurement period. A questionnaire disclosed that low back pain is a common complaint of hockey players, but rarely required intensive physical and medical treatment. The term 'hockey player's back' has been coined in recognition of the long flat thoracolumbar spine frequently noted in these subjects. Copyright © 1988 Australian Physiotherapy Association. Published by . All rights reserved.

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

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

    2017-08-01

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

  7. Prevalence of Os Styloideum in National Hockey League Players

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

    2017-01-01

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

  8. Nutrition review for hockey players : enhancing performance through nutrition

    Bursich, Chris

    2011-01-01

    With the advancement of sports medicine in the past decade, hockey players all over the world are always trying to find a competitive edge through nutritional education and proper eating. It is very common to find young junior players looking to make the jump into the professional game always trying to find ways to get bigger and add lean muscle mass, likewise, there are always players looking to drop a few pounds while keeping their muscle mass. Research has proven that through proper educat...

  9. Self-esteem and injury in competitive field hockey players.

    Kolt, G S; Roberts, P D

    1998-08-01

    A volunteer sample of 50 competitive field hockey players completed the Coopersmith Self-esteem Inventory at pre- and postseason and prospectively collected injury data over a 20-wk. season. Multiple regression analysis showed no relationship between scores on Self-esteem and the number of injuries, the participation time affected due to injury, and sex of players. Further multiple regression analysis showed that frequency of the more severe injuries significantly predicted scores on Self-esteem. This finding can be interpreted as evidence of the relationship between low self-esteem and injury in sport.

  10. Self-appraisal of hockey players of high class of different playing position

    Oleksiy Mikhnov

    2014-12-01

    Full Text Available Purpose: to expose the features of display of self-appraisal for the hockey players of high class of different playing position. Material and Methods: for the exposure of level of self-appraisal for hockey players, information of sportsmen of high class, taking part in the matches of the Kontinental hockey league (KHL in a season 2013–2014 was probed sixteen hockey players, having a sporting digit MS and MSWC, took part in researches. Methods were used: pedagogical supervision, pedagogical analysis and generalization of front-rank experience, psychological testing, analysis of data of the special scientific-methodical literature, expert questioning, an analysis of data is the Internet. Results: findings allowed to set that the players of line of attack (central and extreme forward have more high level of self-appraisal for certain, than players of defence and hockey goalkeepers. This tendency is looked over both on the separate constituents of self-appraisal and on the whole on all spectrums of the studied indexes. The got results of researches rotined that the hockey players of high class had or middle or high level of self-appraisal. Among testable hockey players, players were not exposed with the low level of self-appraisal. Conclusions: the exposed distinctions in the level of self-appraisal of hockey players of high class can be used for diagnostics of playing predisposition and choice of playing line of business in a command.

  11. Expert-novice differences in brain function of field hockey players.

    Wimshurst, Z L; Sowden, P T; Wright, M

    2016-02-19

    The aims of this study were to use functional magnetic resonance imaging to examine the neural bases for perceptual-cognitive superiority in a hockey anticipation task. Thirty participants (15 hockey players, 15 non-hockey players) lay in an MRI scanner while performing a video-based task in which they predicted the direction of an oncoming shot in either a hockey or a badminton scenario. Video clips were temporally occluded either 160 ms before the shot was made or 60 ms after the ball/shuttle left the stick/racquet. Behavioral data showed a significant hockey expertise×video-type interaction in which hockey experts were superior to novices with hockey clips but there were no significant differences with badminton clips. The imaging data on the other hand showed a significant main effect of hockey expertise and of video type (hockey vs. badminton), but the expertise×video-type interaction did not survive either a whole-brain or a small-volume correction for multiple comparisons. Further analysis of the expertise main effect revealed that when watching hockey clips, experts showed greater activation in the rostral inferior parietal lobule, which has been associated with an action observation network, and greater activation than novices in Brodmann areas 17 and 18 and middle frontal gyrus when watching badminton videos. The results provide partial support both for domain-specific and domain-general expertise effects in an action anticipation task. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. The effect of a complex training program on skating abilities in ice hockey players.

    Lee, Changyoung; Lee, Sookyung; Yoo, Jaehyun

    2014-04-01

    [Purpose] Little data exist on systemic training programs to improve skating abilities in ice hockey players. The purpose of this study was to evaluate the effectiveness of a complex training program on skating abilities in ice hockey players. [Methods] Ten male ice hockey players (training group) that engaged in 12 weeks of complex training and skating training and ten male players (control group) that only participated in 12 weeks of skating training completed on-ice skating tests including a 5 time 18 meters shuttle, t-test, Rink dash 5 times, and line drill before, during, and the training. [Results] Significant group-by-time interactions were found in all skating ability tests. [Conclusion] The complex training program intervention for 12 weeks improved their skating abilities of the ice hockey players.

  13. Mental skill levels of South African male student field hockey players ...

    Mental skill levels of South African male student field hockey players in different playing positions. ... African Journal for Physical Activity and Health Sciences ... The positional results were compared by means of effect sizes (expressed as ...

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

    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 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 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.

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

    Allisse Maxime

    2017-08-01

    Full Text Available 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.

  16. Assessment of basic physical parameters of current Canadian-American National Hockey League (NHL ice hockey players

    Martin Sigmund

    2016-03-01

    Full Text Available Background: Physical parameters represent an important part of the structure of sports performance and significantly contribute to the overall performance of an ice hockey player. Basic physical parameters are also an essential part of a comprehensive player assessment both during the initial NHL draft and further stages of a professional career. For an objective assessment it is desirable to know the current condition of development of monitored somatic parameters with regard to the sports discipline, performance level and gaming position. Objective: The aim of this study was to analyze and present the level of development of basic physical characteristics [Body Height (BH and Body Weight (BW] in current ice hockey players in the Canadian-American NHL, also with respect to various gaming positions. Another aim is to compare the results with relevant data of elite ice hockey players around the world. Methods: The data of 751 ice hockey players (age range: 18-43 years; 100% male from NHL (2014/2015 season are analyzed (goalkeepers, n = 67; defenders, n = 237; forwards, n = 447. Statistical data processing was performed using a single factor ANOVA and Fisher's (LSD post hoc test. The level of statistical significance was tested at a level of p ≤ .05; p ≤ .01. Effect size was expressed according to Cohen's d. Results: Current levels of monitored parameters of NHL players represent the values: BH = 186.0 ± 5.3 cm, BW = 91.7 ± 6.9 kg. Significant differences among positions were found for the BH (goalkeepers > defenders > forwards and BW (defenders > goalkeepers > forwards. Differences among forwards positions were also found for the BH (left wings > right wings > centers and BW (left wings > right wings > centers. Conclusion: The observed values represent the current level of basic physical parameters in professional ice hockey players in the NHL and can be considered

  17. Game Intensity Analysis of Elite Adolescent Ice Hockey Players

    Stanula Arkadiusz

    2014-12-01

    Full Text Available The purpose of this study was to determine ice-hockey players’ playing intensity based on their heart rates (HRs recorded during a game and on the outcomes of an incremental maximum oxygen uptake test. Twenty ice-hockey players, members of the Polish junior national team (U18, performed an incremental test to assess their maximal oxygen uptake (V̇ O2max in the two week’s period preceding 5 games they played at the World Championships. Players’ HRs at the first and second ventilatory thresholds obtained during the test were utilized to determine intensity zones (low, moderate, and high that were subsequently used to classify HR values recorded during each of the games. For individual intensity zones, the following HRs expressed as mean values and as percentages of the maximal heart rate (HRmax were obtained: forwards 148-158 b⋅min-1 (79.5-84.8% HRmax, 159-178 b⋅min-1 (85.4-95.6% HRmax, 179-186 b⋅min-1 (96.1-100.0% HRmax; defensemen 149-153 b⋅min-1 (80.0-82.1% HRmax, 154-175 b⋅min-1 (82.6- 94.0% HRmax, 176-186 b⋅min-1 (94.5-100.0% HRmax. The amount of time the forwards and defensemen spent in the three intensity zones expressed as percentages of the total time of the game were: 54.91 vs. 55.62% (low, 26.40 vs. 22.38% (moderate and 18.68 vs. 22.00% (high. The forwards spent more time in the low intensity zone than the defensemen, however, the difference was not statistically significant. The results of the study indicate that using aerobic and anaerobic metabolism variables to determine intensity zones can significantly improve the reliability of evaluation of the physiological demands of the game, and can be a useful tool for coaches in managing the training process.

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

    Background. The physical demands of field hockey and soccer, based on match analysis, are comparable. As a consequence many exercise scientists and coaches have started to use the same type of field tests for hockey and soccer for the purposes of talent identification and training prescription. The validity of this ...

  19. Multidimensional performance characteristics and standard of performance in talented youth field hockey players : A longitudinal study

    Elferink-Gemser, Marije T.; Visscher, Chris; Lemmink, Koen A. P. M.; Mulder, Theo

    2007-01-01

    To identify performance characteristics that could help predict future elite field hockey players, we measured the anthropometric, physiological, technical, tactical, and psychological characteristics of 30 elite and 35 sub-elite youth players at the end of three consecutive seasons. The mean age of

  20. Today's talented youth field hockey players, the stars of tomorrow? : a study

    Elferink-Gemser, Marije Titia

    2005-01-01

    The aim of the thesis was addressed by conducting research within a group of all talented field hockey players, measuring multidimensional performance characteristics in a sports-specific way, and following talented players across time by adopting a longitudinal study design. With caution because

  1. Role of energy systems in two intermittent field tests in women field hockey players

    Lemmink, Koen A. P. M.; Visscher, Susan H.

    The energetics of 2 field tests that reflect physical performance in intermittent sports (i.e., the Interval Shuttle Sprint Test [ISST] and the Interval Shuttle Run Test [ISRT]) were examined in 21 women field hockey players. The ISST required the players to perform 10 shuttle sprints starting every

  2. Do physical maturity and birth date predict talent in male youth ice hockey players?

    Sherar, Lauren B; Baxter-Jones, Adam D G; Faulkner, Robert A; Russell, Keith W

    2007-06-01

    The aim of this study was to examine the relationships among biological maturity, physical size, relative age (i.e. birth date), and selection into a male Canadian provincial age-banded ice hockey team. In 2003, 619 male ice hockey players aged 14-15 years attended Saskatchewan provincial team selection camps, 281 of whom participated in the present study. Data from 93 age-matched controls were obtained from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-1997). During the initial selection camps, birth dates, heights, sitting heights, and body masses were recorded. Age at peak height velocity, an indicator of biological maturity, was determined in the controls and predicted in the ice hockey players. Data were analysed using one-way analysis of variance, logistic regression, and a Kolmogorov-Smirnov test. The ice hockey players selected for the final team were taller, heavier, and more mature (P born in the months January to June. In conclusion, team selectors appear to preferentially select early maturing male ice hockey players who have birth dates early in the selection year.

  3. Incidence of concussions in youth ice hockey players

    Linzmeier, Kathleen A.; LaBella, Cynthia R.

    2016-01-01

    Investigators from the University of Pittsburg, University of Arkansas, Lake Erie College of Osteopathic Medicine, and Boston Children’s Hospital/Harvard Medical College researched the incidence of concussions in youth hockey in relation to age and activity setting.

  4. Comparison of dynamic balance in collegiate field hockey and football players using star excursion balance test.

    Bhat, Rashi; Moiz, Jamal Ali

    2013-09-01

    The preliminary study aimed to compare dynamic balance between collegiate athletes competing or training in football and hockey using star excursion balance test. A total thirty university level players, football (n = 15) and field hockey (n = 15) were participated in the study. Dynamic balance was assessed by using star excursion balance test. The testing grid consists of 8 lines each 120 cm in length extending from a common point at 45° increments. The subjects were instructed to maintain a stable single leg stance with the test leg with shoes off and to reach for maximal distance with the other leg in each of the 8 directions. A pencil was used to point and read the distance to which each subject's foot reached. The normalized leg reach distances in each direction were summed for both limbs and the total sum of the mean of summed normalized distances of both limbs were calculated. There was no significant difference in all the directions of star excursion balance test scores in both the groups. Additionally, composite reach distances of both groups also found non-significant (P=0.5). However, the posterior (P=0.05) and lateral (P=0.03) normalized reach distances were significantly more in field hockey players. Field hockey players and football players did not differ in terms of dynamic balance.

  5. Validation of the FAST skating protocol to predict aerobic power in ice hockey players.

    Petrella, Nicholas J; Montelpare, William J; Nystrom, Murray; Plyley, Michael; Faught, Brent E

    2007-08-01

    Few studies have reported a sport-specific protocol to measure the aerobic power of ice hockey players using a predictive process. The purpose of our study was to validate an ice hockey aerobic field test on players of varying ages, abilities, and levels. The Faught Aerobic Skating Test (FAST) uses an on-ice continuous skating protocol on a course measuring 160 feet (48.8 m) using a CD to pace the skater with a beep signal to cross the starting line at each end of the course. The FAST incorporates the principle of increasing workload at measured time intervals during a continuous skating exercise. Step-wise multiple regression modelling was used to determine the estimate of aerobic power. Participants completed a maximal aerobic power test using a modified Bruce incremental treadmill protocol, as well as the on-ice FAST. Normative data were collected on 406 ice hockey players (291 males, 115 females) ranging in age from 9 to 25 y. A regression to predict maximum aerobic power was developed using body mass (kg), height (m), age (y), and maximum completed lengths of the FAST as the significant predictors of skating aerobic power (adjusted R2 = 0.387, SEE = 7.25 mL.kg-1.min-1, p < 0.0001). These results support the application of the FAST in estimating aerobic power among male and female competitive ice hockey players between the ages of 9 and 25 years.

  6. Development of the interval endurance capacity in elite and sub-elite youth field hockey players

    Elferink-Gemser, MT; Visscher, C; van Duijn, MAJ; Lemmink, KAPM

    Objectives: To gain more insight into the mechanisms that underlie the development of interval endurance capacity in talented youth field hockey players in the 12-19 age band. Methods: A total of 377 measurements were taken over three years. A longitudinal model for interval endurance capacity was

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

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

    2013-01-01

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

  8. Knee joint position sense of roller hockey players: a comparative study.

    Venâncio, João; Lopes, Diogo; Lourenço, Joaquim; Ribeiro, Fernando

    2016-06-01

    This study aimed to compare knee joint position sense of roller hockey players with an age-matched group of non-athletes. Forty-three male participants voluntarily participated in this cross-sectional study: 21 roller hockey players (mean age: 23.2 ± 4.2 years old, mean weight: 81.8 ± 9.8 kg, mean height: 180.5 ± 4.1 cm) and 22 age-matched non-athletes (mean age: 23.7 ± 3.9 years old, mean weight: 85.0 ± 6.2 kg, mean height: 181.5 ± 5.0 cm). Knee joint position sense of the dominant limb was evaluated using a technique of open-kinetic chain and active knee positioning. Joint position sense was reported using absolute, relative and variable angular errors. The main results indicated that the group of roller hockey players showed significantly lower absolute (2.4 ± 1.2º vs. 6.5 ± 3.2º, p ≤ 0.001) and relative (1.7 ± 2.1º vs. 5.8 ± 4.4º, p ≤ 0.001) angular errors in comparison with the non-athletes group. In conclusion, the results from this present study suggest that proprioceptive acuity, assessed by measuring joint position sense, is increased in roller hockey players. The enhanced proprioception of the roller hockey players could contribute to injury prevention and improved performance during sporting activities.

  9. Physical fitness and performance of polish ice-hockey players competing at different sports levels

    Roczniok Robert

    2016-06-01

    Full Text Available The study aimed to determine the values of selected aerobic and anaerobic capacity variables, physical profiles, and to analyze the results of on-ice tests performed by ice-hockey players relegated to a lower league. Performance of 24 ice-hockey players competing in the top league in the 2012/2013 season was analysed to this end. In the 2013/2014 season, 14 of them still played in the top league (the control group, while 10 played in the first league (the experimental group. The study was conducted one week after the end of the playoffs in the seasons under consideration. The results revealed that only in the experimental group the analysed variables changed significantly between the seasons. In the Wingate test, significant changes were only noted in mean relative power (a decrease from 9.91 to 9.14 W/kg; p=0.045 and relative total work (a decrease from 299.17 to 277.22 J/kg; p=0.048. The ramp test indicated significantly lower power output in its final stages (364 compared with 384 W; p=0.034, as well as a significant decrease in relative VO2max (from 52.70 to 48.30 ml/min/kg. Blood lactate concentrations were recorded at the 3rd, 6th, 9th and 12th min of recovery after the ramp test. The rate of post-exercise recovery, ∆LA, recorded after the ramp test turned out to be significantly lower. The times recorded in the on-ice “6x30 m stop” test increased from 32.18 to 33.10 s (p=0.047. The study showed that playing in a lower league where games were less intensive, training sessions shorter and less frequent, had an adverse effect on the performance level of the investigated players. Lower VO2max recorded in the study participants slowed down their rates of post-exercise recovery and led to a significantly worse performance in the 6x30 m stop test, as well as lower relative power and relative total work in the Wingate test.

  10. A test of motor skill-specific action embodiment in ice-hockey players.

    Ong, Nicole T; Lohse, Keith R; Chua, Romeo; Sinnett, Scott; Hodges, Nicola J

    2014-07-01

    To further our understanding of the role of the motor system in comprehending action-related sentences, we compared action experts (athletes) to visual experts (fans) and novices when responding with an action-specific effector (either hand or foot). These conditions allowed inferences about the degree and specificity of embodiment in language comprehension. Ice hockey players, fans and novices made speeded judgments regarding the congruence between an auditorily presented sentence and a subsequently presented picture. Picture stimuli consisted of either hockey or everyday items. Half of these pictures 'matched' the action implied in the preceding sentence. Further, the action in these images involved either primarily the hand or the foot. For everyday items, action-matched items were responded to faster than action-mismatched items. However, only the players and fans showed the action-match effect for hockey items. There were no consistent effector-stimuli compatibility effects, nor skill-based interactions with compatibility, suggesting that the action-match effect was not based on motor ability per se, but rather a construction of the action based on knowledge or visual experience with the hockey related sentences. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Skating start propulsion: three-dimensional kinematic analysis of elite male and female ice hockey players.

    Shell, Jaymee R; Robbins, Shawn M K; Dixon, Philippe C; Renaud, Philippe J; Turcotte, René A; Wu, Tom; Pearsall, David J

    2017-09-01

    The forward skating start is a fundamental skill for male and female ice hockey players. However, performance differences by athlete's sex cannot be fully explained by physiological variables; hence, other factors such as skating technique warrant examination. Therefore, the purpose of this study was to evaluate the body movement kinematics of ice hockey skating starts between elite male and female ice hockey participants. Male (n = 9) and female (n = 10) elite ice hockey players performed five forward skating start accelerations. An 18-camera motion capture system placed on the arena ice surface captured full-body kinematics during the first seven skating start steps within 15 meters. Males' maximum skating speeds were greater than females. Skating technique sex differences were noted: in particular, females presented ~10° lower hip abduction throughout skating stance as well as ~10° greater knee extension at initial ice stance contact, conspicuously followed by a brief cessation in knee extension at the moment of ice contact, not evident in male skaters. Further study is warranted to explain why these skating technique differences exist in relation to factors such as differences in training, equipment, performance level, and anthropometrics.

  12. Heart Rate and Energy Expenditure in Division I Field Hockey Players During Competitive Play.

    Sell, Katie M; Ledesma, Allison B

    2016-08-01

    Sell, KM and Ledesma, AB. Heart rate and energy expenditure in Division I field hockey players during competitive play. J Strength Cond Res 30(8): 2122-2128, 2016-The purpose of this study was to quantify energy expenditure and heart rate data for Division I female field hockey players during competitive play. Ten female Division I collegiate field hockey athletes (19.8 ± 1.6 years; 166.4 ± 6.1 cm; 58.2 ± 5.3 kg) completed the Yo-Yo intermittent endurance test to determine maximal heart rate. One week later, all subjects wore a heart rate monitor during a series of 3 matches in an off-season competition. Average heart rate (AvHR), average percentage of maximal heart rate (AvHR%), peak exercise heart rate (PExHR), and percentage of maximal heart rate (PExHR%), time spent in each of the predetermined heart rate zones, and caloric expenditure per minute of exercise (kcalM) were determined for all players. Differences between positions (backs, midfielders, and forwards) were assessed. No significant differences in AvHR, AvHR%, PExHR, PExHR%, and %TM were observed between playing positions. The AvHR% and PExHR% for each position fell into zones 4 (77-93% HRmax) and 5 (>93% HRmax), respectively, and significantly more time was spent in zone 4 compared with zones 1, 2, 3, and 5 across all players (p ≤ 0.05). The kcalM reflected very heavy intensity exercise. The results of this study will contribute toward understanding the sport-specific physiological demands of women's field hockey and has specific implications for the duration and schedule of training regimens.

  13. The Size and Strength Development in Elite Youth Ice Hockey Players

    Jeff R. Leiter

    2016-07-01

    Full Text Available Background: Ice hockey is a fast, physical sport that requires high levels of muscular strength, muscular endurance and agility. Objectives: This study was conducted to create a profile including: anthropometric measurement, muscular strength, muscular endurance, lower body jump height and distance, and agility characteristics for elite youth hockey players.  Methods: Pre-season off-ice testing results were retrospectively reviewed from a human performance database.  Variables included height, weight, body fat percentage, grip strength, push-ups/bench press, supine rows, the plank test, vertical jump, standing long jump, hip adductor and abductor strength, and the 5-10-5 shuttle, and. One-way ANOVAs (1group x 4 time and Tukeys post-hoc tests were performed to determine changes in the immediately successive age group (p<0.05. Results: Participants included male Bantam-(age: 13-14 and Midget-(age: 15-17 AAA ice-hockey players (n=260.  Age categories were grouped as 13 years old (yo(n=75, 14 yo (n=70, 15 yo (n=58, and 16-17 yo (n=57.  Increases between successive age groups were observed in the following variables: weight (13, 14, 15 and 16-17 yo, height (13 and 14 yo, left and right grip strength (13, 14, 15, and 16-17 yo, bench press (15 and 16-17 yo, left and right hip abduction (14, 15, and 16-17 yo, and vertical and standing long jump (13, 14, and 15 yo. Total time for the 5-10-5 shuttle run test decreased from 13 to 14yo, and 14 to 15 yo. Conclusion: Changes with age in off-ice performance variables of elite amateur hockey players should be recognized, followed, and addressed during player development to maximize the potential for elite performance and reduce the risk of injury.   Keywords: Athletic Performance, Training, Physical Fitness

  14. Improvement of Ice Hockey Players' On-Ice Sprint With Combined Plyometric and Strength Training.

    Dæhlin, Torstein E; Haugen, Ole C; Haugerud, Simen; Hollan, Ivana; Raastad, Truls; Rønnestad, Bent R

    2017-08-01

    Combined plyometric and strength training has previously been suggested as a strategy to improve skating performance in ice hockey players. However, the effects of combined plyometric and strength training have not previously been compared with the effects of strength training only. To compare the effects of combined plyometric and strength training on ice hockey players' skating sprint performance with those of strength training only. Eighteen participants were randomly assigned to 2 groups that completed 5 strength-training sessions/wk for 8 wk. One group included plyometric exercises at the start of 3 sessions/wk (PLY+ST), and the other group included core exercises in the same sessions (ST). Tests of 10- and 35-m skating sprints, horizontal jumping, 1-repetition-maximum (1 RM) squat, skating multistage aerobic test (SMAT), maximal oxygen consumption, repeated cycle sprints, and body composition were performed before and after the intervention. The participants increased their 1RM squat, lean mass, and body mass (P plyometric and strength training for 8 wk was superior to strength training alone at improving 10-m on-ice sprint performance in high-level ice hockey players.

  15. Effectiveness of interventions to reduce aggression and injuries among ice hockey players: a systematic review

    Cusimano, Michael D.; Nastis, Sofia; Zuccaro, Laura

    2013-01-01

    Background: The increasing incidence of injuries related to playing ice hockey is an important public health issue. We conducted a systematic review to evaluate the effectiveness of interventions designed to reduce injuries related to aggressive acts in ice hockey. Methods: We identified relevant articles by searching electronic databases from their inception through July 2012, by using Internet search engines, and by manually searching sports medicine journals, the book series Safety in Ice Hockey and reference lists of included articles. We included studies that evaluated interventions to reduce aggression-related injuries and reported ratings of aggressive behaviour or rates of penalties or injuries. Results: We identified 18 eligible studies. Most involved players in minor hockey leagues. Of 13 studies that evaluated changes in mandatory rules intended to lessen aggression (most commonly the restriction of body-checking), 11 observed a reduction in penalty or injury rates associated with rule changes, and 9 of these showed a statistically significant decrease. The mean number of penalties decreased by 1.2–5.9 per game, and injury rates decreased 3- to 12-fold. All 3 studies of educational interventions showed a reduction in penalty rates, but they were not powered or designed to show a change in injury rates. In 2 studies of cognitive behavioural interventions, reductions in aggressive behaviours were observed. Interpretation: Changes to mandatory rules were associated with reductions in penalties for aggressive acts and in injuries related to aggression among ice hockey players. Effects of educational and cognitive behavioural interventions on injury rates are less clear. Well-designed studies of multifaceted strategies that combine such approaches are required. PMID:23209118

  16. Movement Characteristics and Heart Rate Profiles Displayed by Female University Ice Hockey Players

    Joel Jackson

    2016-01-01

    Full Text Available Background: Women’s ice hockey is widely popular but the various movement patterns, heart rate responses and work to rest ratios during competitive games has not been adequately investigated.  Objectives: This study determined the frequency and duration of movements that female players perform in ice hockey games using time-motion analysis. The intensity of the game activities were also assessed by heart rate (HR responses and work to rest ratios (W:R. Methods: Twenty-two university female ice hockey players were filmed performing a number of movements during three regular season league games. Results: The following movement patterns were categorized in percent of time performed during the games: forward gliding on ice (36.3 ± 6.2%, forward skating at a moderate intensity (31.2 ± 6.2%, backward glide (9.5 ± 4.1%, standing (7.1 ± 5.9%, struggling (6.3 ± 2.6%, forward skating at maximal intensity (5.3 ± 3.3%, backwards skating at moderate intensity (3.1 ± 3.3%. Defense stood and glided backward more than forwards but skated less at a high or maximal intensity. Positional differences were also observed during different game play situations. The highest HR (±SD achieved during shifts was 182 ± 10 and HR averaged 174 ± 9 bpm for the whole duration of the shifts. The shift and game W:R ratios for all players were 1:1.6 and 1: 3.7, respectively. Conclusions: The findings of this study indicate that female ice hockey games are played at a low to moderate intensity most of the time (~84% of the time spent and are interspersed with brief, intermittent high intensity activities that vary according to player position and game play situation. It was also apparent that female players display markedly high HR responses during game-play indicative of a substantial cardiovascular demand in ice hockey. Keywords: game analysis, work to rest ratios, exercise intensity

  17. The Assessment of Airway Maneuvers and Interventions in University Canadian Football, Ice Hockey, and Soccer Players

    Delaney, J. Scott; Al-Kashmiri, Ammar; Baylis, Penny-Jane; Troutman, Tracy; Aljufaili, Mahmood; Correa, José A.

    2011-01-01

    Abstract Context: Managing an airway in an unconscious athlete is a lifesaving skill that may be made more difficult by the recent changes in protective equipment. Different airway maneuvers and techniques may be required to help ventilate an unconscious athlete who is wearing full protective equipment. Objective: To assess the effectiveness of different airway maneuvers with football, ice hockey, and soccer players wearing full protective equipment. Design: Crossover study. Setting: University sports medicine clinic. Patients or Other Participants: A total of 146 university varsity athletes, consisting of 62 football, 45 ice hockey, and 39 soccer players. Intervention(s): Athletes were assessed for different airway and physical characteristics. Three investigators then evaluated the effectiveness of different bag-valve-mask (BVM) ventilation techniques in supine athletes who were wearing protective equipment while inline cervical spine immobilization was maintained. Main Outcome Measure(s): The effectiveness of 1-person BVM ventilation (1-BVM), 2-person BVM ventilation (2-BVM), and inline immobilization and ventilation (IIV) was judged by each investigator for each athlete using a 4-point rating scale. Results: All forms of ventilation were least difficult in soccer players and most difficult in football players. When compared with 1-BVM, both 2-BVM and IIV were deemed more effective by all investigators for all athletes. Interference from the helmet and stabilizer were common reasons for difficult ventilation in football and ice hockey players. Conclusions: Sports medicine professionals should practice and be comfortable with different ventilation techniques for athletes wearing full equipment. The use of a new ventilation technique, termed inline immobilization and ventilation, may be beneficial, especially when the number of responders is limited. PMID:21391796

  18. Examining the relationship between relative age, competition level, and dropout rates in male youth ice-hockey players.

    Lemez, S; Baker, J; Horton, S; Wattie, N; Weir, P

    2014-12-01

    The relative age effect suggests that athletes born in the first two quartiles of a given selection year experience a selection advantage and therefore a greater opportunity for success. We describe two studies examining the relationship between relative age, competition level, and dropout rates of Ontario Minor Hockey Association male ice-hockey players from ages 10 to 15 years (n = 14 325). In Study 1, dropout was highest among players born in quartiles three and four [χ(2) (3) = 16.32, P < 0.05; w = 0.06], while Study 2 found dropped out players to have less movement between competition levels compared to retained players. This study confirms a relationship between relative age and dropout from ice-hockey and adds further depth to our understanding of this persistent phenomenon. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Motivational climate, goal orientation, perceived sport ability, and enjoyment within Finnish junior ice hockey players.

    Jaakkola, T; Ntoumanis, N; Liukkonen, J

    2016-01-01

    The aim of this study was to investigate the relations among situational motivational climate, dispositional approach and avoidance achievement goals, perceived sport ability, and enjoyment in Finnish male junior ice hockey players. The sample comprised 265 junior B-level male players with a mean age of 17.03 years (SD = 0.63). Players filled questionnaires tapping their perceptions of coach motivational climate, achievement goals, perceived sport ability, and enjoyment. For the statistical analysis, players were divided into high and low perceived sport ability groups. Multigroup structural equation modeling (SEM) revealed an indirect path from task-involving motivational climate via task-approach goal to enjoyment. Additionally, SEM demonstrated four other direct associations, which existed in both perceived ability groups: from ego-involving motivational climate to ego-approach and ego-avoidance goals; from ego-approach goal to ego-avoidance goal; and from task-avoidance goal to ego-avoidance goal. Additionally, in the high perceived sport ability group, there was an association from task-involving motivational climate to enjoyment. The results of this study reveal that motivational climate emphasizing effort, personal development and improvement, and achievement goal mastering tasks are significant elements of enjoyment in junior ice hockey. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Four Weeks of Off-Season Training Improves Peak Oxygen Consumption in Female Field Hockey Players

    Lindsey T. Funch; Erik Lind; Larissa True; Deborah Van Langen; John T. Foley; James F. Hokanson

    2017-01-01

    The purpose of the study was to examine the changes in peak oxygen consumption ( V ˙O2peak) and running economy (RE) following four-weeks of high intensity training and concurrent strength and conditioning during the off-season in collegiate female field hockey players. Fourteen female student-athletes (age 19.29 ± 0.91 years) were divided into two training groups, matched from baseline V ˙O2peak: High Intensity Training (HITrun; n = 8) and High Intensity Interval Training (HIIT; ...

  1. Back Squat Potentiates Both Vertical and Horizontal Jump Performance in Collegiate Ice Hockey Players

    Cale Bechtel

    2018-01-01

    Full Text Available Background: Back squats (BSQ have been shown to transiently improve performance in explosive vertical movements such as the vertical jump (VJ. Still, understanding of this phenomenon, termed post-activation potentiation (PAP, remains nebulous as it relates to explosive horizontal movements. Objective: Therefore, the purpose of the present investigation was to assess whether heavy BSQ can potentiate both VJ and horizontal jump (HJ performance. Method: Nine male ice hockey players from the Long Beach State ice hockey team performed five testing sessions separated by 96-hours. The first testing session consisted of a one repetition maximum (1-RM BSQ to determine subsequent testing loads. The four subsequent testing sessions, which were randomized for order, consisted of five repetitions of BSQ at 87% 1-RM followed by horizontal jump (BSQ-HJ, five repetitions of BSQ at 87% 1-RM followed by vertical jump (BSQ-VJ, horizontal jump only (CT-HJ and vertical jump only (CT-VJ. During the potentiated conditions, rest intervals were set at five minutes between the BSQ and either VJ or HJ. Alpha-level was set a priori at 0.05. Results: The results indicate that both vertical (p=0.017 and horizontal (p=0.003 jump were significantly increased (VJ= +5.51cm, HJ= +11.55cm following a BSQ.  Conclusion: These findings suggest that BSQ may improve both vertical and horizontal jump performance in athletes who participate in sports emphasizing horizontal power, such as ice hockey.

  2. The effect of laryngoscope handle size on possible endotracheal intubation success in university football, ice hockey, and soccer players.

    Delaney, J Scott; Al-Kashmiri, Ammar; Baylis, Penny-Jane; Aljufaili, Mahmood; Correa, José A

    2012-07-01

    To assess the effectiveness of a standard long-handle laryngoscope and a short-handle laryngoscope on ease of possible intubation in football, ice hockey, and soccer players. Prospective crossover study. University Sport Medicine Clinic. Sixty-two university varsity football (62 males), 45 ice hockey (26 males and 19 females), and 39 soccer players (20 males, 19 females). Athletes were assessed for different airway and physical characteristics. Three different physicians then assessed the use of laryngoscopes of different handle sizes in supine athletes who were wearing protective equipment while in-line cervical spine immobilization was maintained. The ease of passage of a laryngoscope blade into the posterior oropharynx of a supine athlete was assessed using both a standard long-handle and a short-handle laryngoscope. Use of a short-handle laryngoscope was easier for all physicians in all sports as compared with a standard-sized laryngoscope. Passage of a laryngoscope blade into the posterior oropharynx of a supine athlete was easiest in soccer players and most difficult in football and ice hockey players for both sizes of laryngoscope. Interference from chest or shoulder pads was a common cause for difficulty in passing the laryngoscope blade into the posterior oropharynx for football and ice hockey players. In the rare instances that an endotracheal intubation is to be attempted on an unconscious athlete, a short-handle laryngoscope may provide the best chance for successful intubation.

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

    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.

  4. Multiparametric MRI changes persist beyond recovery in concussed adolescent hockey players

    Manning, Kathryn Y.; Schranz, Amy; Bartha, Robert; Dekaban, Gregory A.; Barreira, Christy; Brown, Arthur; Fischer, Lisa; Asem, Kevin; Doherty, Timothy J.; Fraser, Douglas D.; Holmes, Jeff

    2017-01-01

    Objective: To determine whether multiparametric MRI data can provide insight into the acute and long-lasting neuronal sequelae after a concussion in adolescent athletes. Methods: Players were recruited from Bantam hockey leagues in which body checking is first introduced (male, age 11–14 years). Clinical measures, diffusion metrics, resting-state network and region-to-region functional connectivity patterns, and magnetic resonance spectroscopy absolute metabolite concentrations were analyzed from an independent, age-matched control group of hockey players (n = 26) and longitudinally in concussed athletes within 24 to 72 hours (n = 17) and 3 months (n = 14) after a diagnosed concussion. Results: There were diffusion abnormalities within multiple white matter tracts, functional hyperconnectivity, and decreases in choline 3 months after concussion. Tract-specific spatial statistics revealed a large region along the superior longitudinal fasciculus with the largest decreases in diffusivity measures, which significantly correlated with clinical deficits. This region also spatially intersected with probabilistic tracts connecting cortical regions where we found acute functional connectivity changes. Hyperconnectivity patterns at 3 months after concussion were present only in players with relatively less severe clinical outcomes, higher choline concentrations, and diffusivity indicative of relatively less axonal disruption. Conclusions: Changes persisted well after players' clinical scores had returned to normal and they had been cleared to return to play. Ongoing white matter maturation may make adolescent athletes particularly vulnerable to brain injury, and they may require extended recovery periods. The consequences of early brain injury for ongoing brain development and risk of more serious conditions such as second impact syndrome or neural degenerative processes need to be elucidated. PMID:29070666

  5. Skating mechanics of change-of-direction manoeuvres in ice hockey players.

    Fortier, Antoine; Turcotte, René A; Pearsall, David J

    2014-11-01

    Ice hockey requires rapid transitions between skating trajectories to effectively navigate about the ice surface. Player performance relates in large part to effective change-of-direction manoeuvres, but little is known about how those skills are performed mechanically and the effect of equipment design on them. The purpose of this study was to observe the kinetics involved in those manoeuvres as well as to compare whether kinetic differences may result between two skate models of varying ankle mobility. Eight subjects with competitive ice hockey playing experience performed rapid lateral (90°) left and right change-of-direction manoeuvres. Kinetic data were collected using force strain gauge transducers on the blade holders of the skates. Significantly greater forces were applied by the outside skate (50-70% body weight, %BW) in comparison to the inside skate (12-24%BW, p Skate model and turn direction had no main effect, though significant mixed interactions between leg side (inside/outside) with skate model or turn direction (p skating change-of-direction tasks.

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

    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.

  7. The relationship between ventilatory threshold and repeated-sprint ability in competitive male ice hockey players

    Matthew R. Lowery

    2018-04-01

    Full Text Available Background/objective: The relationship between ventilatory threshold (VT1, VT2 and repeated-sprint ability (RSA in competitive male ice hockey players was investigated. Methods: Forty-three male ice hockey players aged 18–23 years competing in NCAA Division I, NCAA Division III, and Junior A level participated. Participants performed an incremental graded exercise test on a skate treadmill to determine V˙O2peak, VT1, and VT2 using MedGraphics Breezesuit™ software (v-slope. Participants performed an on-ice repeated shift (RSA test consisting of 8-maximal skating bouts, lasting approximately 25 s and interspersed with 90 s of passive recovery, to determine first gate, second gate, and total sprint decrement (%dec. Pearson product-moment correlations and multiple regressions were used to assess relationships between ventilatory threshold variables (VT1, VT2, Stage at VT1, and Stage at VT2 and RSA (first gate, second gate, and total course decrement. Results: Stage at VT2 was the only variable substantially correlated with first gate (r = −0.35; P < 0.05, second gate (r = −0.58; P < 0.001 and total course decrement (r = −0.42; P < 0.05. Conclusion: The results of this study demonstrated that VT is substantially associated with RSA, and VT2 is more strongly correlated with RSA than V˙O2peak. This study suggests that longer duration high-intensity interval training at intensities that increase workrate at VT2 may lead to possible improvements in RSA. Keywords: Athletes, Aerobic capacity, Fatigue, Sprint decrement

  8. Rationale set of indicators and prioritize relevant to assess competitive activity of hockey players of high qualification of different roles

    A.P. Mikhnov

    2015-02-01

    Full Text Available Purpose: organize technical and tactical actions and determine their priority importance for high-end players of different roles. Establish their priority importance for the success of competitive activity hockey with the game roles. Material : the study involved 54 experts on hockey coaches and players of high class. The significance of technical and tactical actions evaluated for players of different roles. Results : systematic account of technical and tactical actions of athletes and prioritize them to assess the significance of competitive activity. Three groups of technical and tactical actions: 1 active attacks; 2 - active safety; 3 - organizational and maneuvering. Set priorities for technical and tactical actions for players of different roles. Conclusions : the proposed technical and tactical actions can be recommended for the evaluation of the effectiveness of competitive activity players. In the process of estimating the action game players need to consider their role playing. Identification of priority in the implementation of technical and tactical actions in the game can be used in integrated assessment of actions players different roles.

  9. Habituation of 10-year-old hockey players to treadmill skating.

    Lockwood, Kelly L; Frost, Gail

    2007-05-01

    This study assessed changes in selected physiological and kinematic variables over 6 weeks of treadmill skating in an effort to understand the process of habituation to this novel training modality. Seven male, Atom-A hockey players who were injury-free and had no previous treadmill skating experience participated in the study. Players performed four 1-min skating bouts at progressively increasing speeds, each week, for 6 weeks. One speed (10.5 km/h) was repeated weekly to allow for assessment of the habituation process. Our criteria for habituation were: a decrease in stride rate, heart rate and rating of perceived exertion, and an increase in stride length, trunk angle and vertical movement of the centre of mass, leading to a plateau, over the course of the 6-week study. Significant decreases were seen in stride rate, heart rate and ratings of perceived exertion, and significant increases were found in stride length. Some of these changes were evident after only one week of training and all were present by week 4. After 6 weeks (24 min) of exposure to treadmill skating, all participants displayed a visibly more efficient skating style.

  10. The Role of Visual Feedback on Power Output During Intermittent Wingate Testing in Ice Hockey Players

    Petr Stastny

    2018-04-01

    Full Text Available Background: Visual feedback may help elicit peak performance during different types of strength and power testing, but its effect during the anaerobic Wingate test is unexplored. Therefore, the purpose of this study was to determine the effect of visual feedback on power output during a hockey-specific intermittent Wingate test (AnWT6x6 consisting of 6 stages of 6 s intervals with a 1:1 work-to-rest ratio. Methods: Thirty elite college-aged hockey players performed the AnWT6x6 with either constant (n = 15 visual feedback during all 6 stages (CVF or restricted (n = 15 visual feedback (RVF where feedback was shown only during the 2nd through 5th stages. Results: In the first stage, there were moderate-to-large effect sizes for absolute peak power (PP output and PP relative to body mass and PP relative to fat-free mass. However, the remaining stages (2–6 displayed small or negligible effects. Conclusions: These data indicate that visual feedback may play a role in optimizing power output in a non-fatigued state (1st stage, but likely does not play a role in the presence of extreme neuromuscular fatigue (6th stage during Wingate testing. To achieve the highest peak power, coaches and researchers could provide visual feedback during Wingate testing, as it may positively influence performance in the early stages of testing, but does not result in residual fatigue or negatively affect performance during subsequent stages.

  11. A Comparison of Somatic Variables of Elite Ice Hockey Players from the Czech ELH and Russian KHL

    Kutáč Petr

    2015-03-01

    Full Text Available The goals of this study were to evaluate the basic morphological variables of contemporary elite ice hockey players, compare the parameters of players in the top Russian ice hockey league (KHL with those of the top Czech ice hockey league (ELH, and to evaluate the parameters of players according to their position in the game. The research participants included 30 KHL players (mean age: 27.1 ± 5.1 years and 25 ELH players (mean age: 26.4 ± 5.8 years. We determined body height, body mass, and body composition (body fat, fat-free mass, segmental fat analysis. All measurements were performed at the end of preseason training. The KHL players had the following anthropometric characteristics: body height 182.97 ± 5.61 cm (forward and 185.72 ± 3.57 cm (defenseman, body mass 89.70 ± 5.28 kg (forward and 92.52 ± 4.01 kg (defenseman, body fat 10.76 ± 0.63 kg (forward and 11.10 ± 0.48 kg (defenseman, fatfree mass 78.94 ± 4.65 kg (forward and 81.42 ± 3.52 kg (defenseman. The values for ELH players were as follows: body height 182.06 ± 5.93 cm (forward and 185.88 ± 7.13 cm (defenseman, body mass 88.47 ± 7.06 kg (forward and 89.36 ± 10.91 kg (defenseman, body fat 12.57 ± 2.89 kg (forward and 11.91 ± 3.10 kg (defenseman, fat-free mass 75.93 ± 6.54 kg (forward and 77.46 ± 7.89 kg (defenseman. The results indicate that it is beneficial to ice hockey players to have increased body mass and lower body fat, which leads to higher muscle mass, thus enabling a player to perform at the highest level and meet the specific challenges of the game.

  12. Muscle Power and Velocity During Trunk Rotations after 6 Weeks of Training in Ice-Hockey Players

    Poór Oliver

    2017-05-01

    Full Text Available The study evaluates changes of muscle power and velocity during trunk rotations in ice-hockey players after six weeks of training in competition period. A group of 15 ice-hockey players performed 2 trunk rotations to each direction in a standing position with barbell of 6, 10, 12, 16, 20, 22, 26 kg placed on the shoulders. Basic biomechanical parameters during the movement were monitored using the FiTRO Torso Dyne system. Results showed that mean velocity in acceleration phase of trunk rotation significantly increased after 6 weeks of training at 6 kg (from 259 to 282.6 deg/s, p = 0.003 and 12 kg (from 218.8 to 244.1 deg/s p = 0.004. However, its values did not changed significantly during rotations with 10, 16, 20, 22 and 26 kg. Mean power of trunk rotation did not changed significantly with any of used weight. These findings indicate that there are only small changes in muscle power in competition period of ice hockey-players.

  13. [The relevance of core muscles in ice hockey players: a feasibility study].

    Rogan, S; Blasimann, A; Nyffenegger, D; Zimmerli, N; Radlinger, L

    2013-12-01

    Good core strength is seen as a condition for high performance in sports. In general, especially maximum voluntary contraction (MVC) and strength endurance (SE) measurements of the core muscles are used. In addition, a few studies can be found that examine the core muscles in terms of MVC, rate of force development (RFD) and SE. Primary aims of this feasibility study were to investigate the feasibility regarding recruiting process, compliance and safety of the testing conditions and raise the force capabilities MVC, RFD and SE of the core muscles in amateur ice hockey players. Secondarily, tendencies of correlations between muscle activity and either shot speed and sprint time shall be examined. In this feasibility study the recruitment process has been approved by 29 ice hockey players, their adherence to the study measurements of trunk muscles, and safety of the measurements was evaluated. To determine the MVC, RFD and SE for the ventral, lateral and dorsal core muscles a dynamic force measurement was performed. To determine the correlation between core muscles and shot speed and 40-m sprint, respectively, the rank correlation coefficient (rho) from Spearman was used. The recruited number of eight field players and one goal-keeper was not very high. The compliance with 100 % was excellent. The players reported no adverse symptoms or injuries after the measurements. The results show median values for the ventral core muscles for MVC with 46.5 kg for RFD with 2.23 m/s2 and 96 s for the SE. For lateral core muscle median values of the lateral core muscles for MVC with 71.10 kg, RFD with 2.59 m/s2 and for SE over 66 s were determined. The dorsal core muscles shows values for MVC 69.7 kg, for RFD 3.39 m/s2 and for SE of 75 s. High correlations between MVC of the ventral core muscles (rho = -0.721, p = 0.021), and between the SE of the ventral core muscles (rho = 0.787, p = 0.012), and the shot velocity rate were determined. Another

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

    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 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.

  15. Upper respiratory tract infection and mucosal immunity in young ice hockey players during the pre-tournament training period.

    Orysiak, Joanna; Witek, Konrad; Malczewska-Lenczowska, Jadwiga; Zembron-Lacny, Agnieszka; Pokrywka, Andrzej; Sitkowski, Dariusz

    2018-02-27

    The aim of this study was to determine the effects of 17 days of training during preparation for the Ice Hockey Under 18 World Championship of the Polish ice hockey national team on the mucosal immune function and monitor upper respiratory tract infection (URTI) incidence before, during and after the competition. Twelve male ice hockey players (age 17.7±0.5 years) were recruited for this study. The first saliva/blood collection took place at the beginning of the training camp (without training at the training camp), the second one was conducted on the 9th day of the training camp immediately after the intensification of training, and the third collection was carried out on the 13th day of training (4 days before leaving for the World Championship) in the tapering phase. To assess the mucosal immune function, concentrations of secretory immunoglobulin A (sIgA), sIgA1, and sIgA2 were analyzed in saliva. Cortisol concentration and creatine kinase activity were determined in blood, as indicators of stress and muscle damage, respectively. The Wisconsin Upper Respiratory Symptom Survey-21 questionnaire was used to assess URTI symptoms. A significant increase in the sIgA1 and sIgA2 concentrations was observed in the third collection compared with the second time point (114.45±33.00 vs 77.49±27.29 and 88.97±25.33 vs 71.65±32.44 U, respectively). There were no statistically significant correlations between the URTI incidence and saliva variables. In conclusion, the tapering period positively affects the mucosal immune function, especially sIgA1 and sIgA2 concentrations, with no significant change in frequency of URTI in young ice hockey players.

  16. PENGEMBANGAN MODEL ALAT STICK HOCKEY UNTUK LATIHAN PEMAIN PEMULA HOCKEY

    In’am Attaqi

    2016-10-01

    Full Text Available Background issues that hamper the development of hockey in Central Java due to the lack of means of stick that is expensive and so difficult to get it. The focus of this research problem is to design products hockey stick model development tool for training novice players and test products hockey stick model development tool for training novice players.The approach used in this research is the Research and Development. Phase of the study include preliminary research, design modeling, model development testing procedures, expert Judgment, small-scale trials, trials broad scale. The subject of this study is Mts Miftahussalam 1 Wonosalam Demak. Hockey expert of experts and specialists timber expert. The data analysis phase of field work and data analysis stage include observation, observation, interviews, documentation and effectiveness testing of products, expert judgment hockey expert of experts and specialists timber expert.The results of this study are the product hockey stick for beginner hockey players training in Mts Miftahussalam 1 Wonosalam.PANDAWA hockey stick product can be used as a means of practicing basic techniques for beginner hockey players, hockey stick PANDAWA product can be used as a training tool in improving the ability of the basic techniques of playing hockey, hockey stick PANDAWA product can be used as a means of playing hockey for the novice player.

  17. Thoracic Outlet Syndrome and Volkmann's Contracture in a Field Hockey Player

    Morgan Sawyer

    2016-05-01

    Full Text Available Background: A 19-year-old female field hockey player presents with bilateral upper trapezius and rhomboid tightness and spasm beginning in January of 2016. She has no previous history of upper back pain or injury. The student first reported the injury immediately after running sprints. She stated that she could not move or feel her fingers or hands. She presents with a visible hump on her left upper trapezius. She also has forward-rounded shoulders. She has regular and equal radial pulses. She has decreased sensation upon palpation of her fingers, hands and forearms. After extraneous exercise, the athlete’s hands, wrists and forearms go into contracture and flexion and she is unable to move from this position until manual extension is applied, or 10 or more minutes of rest occurs. She is TTP over her upper trapezius musculature. She had a positive Military Brace test. Differential Diagnosis: Based on evaluation, the athlete could simply just have upper trapezius musculature spasms. The diagnosis could also be shoulder impingement syndrome, due to the neurological signs and symptoms. Compartment syndrome could produce similar s/s that the athlete experiences, as well. Treatment: X-rays show no bony abnormalities and no extra ribs. The athlete’s injury has been treated with ice post-practice, heat pre-practice and upper body stretching exercises. Three days a week the athlete works on postural exercises that strengthen her back musculature. The athlete also receives combination therapy over her upper trapezius trigger points, along with massage and Hawkgrip technique over the same areas. Uniqueness: The uniqueness in this case is that the athlete has both TOS and Volkmann’s contracture. Volkmann’s contractures typically occur in pediatrics, which is another reason why this particular case is unique. Conclusion: This case allows other clinicians to understand the causes of TOS and the secondary s/s that TOS can potentially cause.

  18. Four Weeks of Off-Season Training Improves Peak Oxygen Consumption in Female Field Hockey Players

    Lindsey T. Funch

    2017-11-01

    Full Text Available The purpose of the study was to examine the changes in peak oxygen consumption ( V ˙O2peak and running economy (RE following four-weeks of high intensity training and concurrent strength and conditioning during the off-season in collegiate female field hockey players. Fourteen female student-athletes (age 19.29 ± 0.91 years were divided into two training groups, matched from baseline V ˙O2peak: High Intensity Training (HITrun; n = 8 and High Intensity Interval Training (HIIT; n = 6. Participants completed 12 training sessions. HITrun consisted of 30 min of high-intensity running, while HIIT consisted of a series of whole-body high intensity Tabata-style intervals (75–85% of age predicted maximum heart rate for a total of four minutes. In addition to the interval training, the off-season training included six resistance training sessions, three team practices, and concluded with a team scrimmage. V ˙O2peak was measured pre- and post-training to determine the effectiveness of the training program. A two-way mixed (group × time ANOVA showed a main effect of time with a statistically significant difference in V ˙O2peak from pre- to post-testing, F(1, 12 = 12.657, p = 0.004, partial η2 = 0.041. Average (±SD V ˙O2peak increased from 44.64 ± 3.74 to 47.35 ± 3.16 mL·kg−1·min−1 for HIIT group and increased from 45.39 ± 2.80 to 48.22 ± 2.42 mL·kg−1·min−1 for HITrun group. Given the similar improvement in aerobic power, coaches and training staff may find the time saving element of HIIT-type conditioning programs attractive.

  19. Muscle oxygen changes following Sprint Interval Cycling training in elite field hockey players.

    Ben Jones

    Full Text Available This study examined the effects of Sprint Interval Cycling (SIT on muscle oxygenation kinetics and performance during the 30-15 intermittent fitness test (IFT. Twenty-five women hockey players of Olympic standard were randomly selected into an experimental group (EXP and a control group (CON. The EXP group performed six additional SIT sessions over six weeks in addition to their normal training program. To explore the potential training-induced change, EXP subjects additionally completed 5 x 30s maximal intensity cycle testing before and after training. During these tests near-infrared spectroscopy (NIRS measured parameters; oxyhaemoglobin + oxymyoglobin (HbO2+ MbO2, tissue deoxyhaemoglobin + deoxymyoglobin (HHb+HMb, total tissue haemoglobin (tHb and tissue oxygenation (TSI % were taken. In the EXP group (5.34 ± 0.14 to 5.50 ± 0.14 m.s(-1 but not the CON group (pre = 5.37 ± 0.27 to 5.39 ± 0.30 m.s(-1 significant changes were seen in the 30-15 IFT performance. EXP group also displayed significant post-training increases during the sprint cycling: ΔTSI (-7.59 ± 0.91 to -12.16 ± 2.70%; ΔHHb+HMb (35.68 ± 6.67 to 69.44 ± 26.48 μM.cm; and ΔHbO2+ MbO2 (-74.29 ± 13.82 to -109.36 ± 22.61 μM.cm. No significant differences were seen in ΔtHb (-45.81 ± 15.23 to -42.93 ± 16.24. NIRS is able to detect positive peripheral muscle oxygenation changes when used during a SIT protocol which has been shown to be an effective training modality within elite athletes.

  20. Multidisciplinary approach to non-surgical management of inguinal disruption in a professional hockey player treated with platelet-rich plasma, manual therapy and exercise: a case report.

    St-Onge, Eric; MacIntyre, Ian G; Galea, Anthony M

    2015-12-01

    To present the clinical management of inguinal disruption in a professional hockey player and highlight the importance of a multidisciplinary approach to diagnosis and management. A professional hockey player with recurrent groin pain presented to the clinic after an acute exacerbation of pain while playing hockey. The patient received a clinical diagnosis of inguinal disruption. Imaging revealed a tear in the rectus abdominis. Management included two platelet-rich plasma (PRP) injections to the injured tissue, and subsequent manual therapy and exercise. The patient returned to his prior level of performance in 3.5 weeks. This case demonstrated the importance of a multidisciplinary team and the need for advanced imaging in athletes with groin pain. Research quality concerning the non-surgical management of inguinal disruption remains low. This case adds evidence that PRP, with the addition of manual therapy and exercise may serve as a relatively quick and effective non-surgical management strategy.

  1. Relationship Between Skating Economy and Performance During a Repeated-Shift Test in Elite and Subelite Ice Hockey Players.

    Lamoureux, Nicholas R; Tomkinson, Grant R; Peterson, Benjamin J; Fitzgerald, John S

    2018-04-01

    Lamoureux, NR, Tomkinson, GR, Peterson, BJ, and Fitzgerald, JS. Relationship between skating economy and performance during a repeated-shift test in elite and subelite ice hockey players. J Strength Cond Res 32(4): 1109-1113, 2018-The purpose of this study was to determine the importance of skating economy to fatigue during repeated high-intensity efforts of a simulated ice hockey shift. Forty-five collegiate and Junior A male ice hockey players (aged 18-24 years) performed a continuous graded exercise test using a skate treadmill. Breath-by-breath data for oxygen consumption (V[Combining Dot Above]O2) and respiratory exchange ratio were collected and used to derive energy expenditure (EE) averaged over the final 10 seconds of each stage. Economy was determined as the slope of the regression line relating V[Combining Dot Above]O2 and EE against skating speed separately. Participants also completed 8 bouts of maximal ice skating through a course designed to simulate typical shift, with timing gates determining first half, second half, and total fatigue decrement, calculated by a percent decrement score. Partial correlation was used to determine the association between economy measures and decrement during the repeated-shift test. Twenty-six participants met inclusion criteria and were included in data analysis. Skating economy measures (both relative V[Combining Dot Above]O2 and EE) were very likely moderate positive correlates of total fatigue decrement (r [95% confidence interval]: V[Combining Dot Above]O2, 0.46 [0.09, 0.72] and EE, 0.44, [0.06, 0.71]) but not with first or second gate decrement. Our results indicate that skating economy plays an important role in fatigue resistance over repeated on-ice sprints designed to simulate a typical shift. This supports the use of technical skating coaching and training techniques to enhance skating economy as a means of improving ice hockey performance.

  2. Using Elite Athletes to Promote Drug Abstinence: Evaluation of a Single-Session School-Based Drug Use Prevention Program Delivered by Junior Hockey Players

    Wong, Jennifer

    2016-01-01

    School-based substance use prevention programs are a common method to approaching drug use in youths. Project SOS is a single-session drug prevention program developed by police officers and delivered by elite junior hockey players to students in grades 6 and 7. The current study evaluates the effects of Project SOS at achieving its objectives of…

  3. Relationship between Physiological Off-Ice Testing, On-Ice Skating, and Game Performance in Division I Women's Ice Hockey Players.

    Boland, Michelle; Miele, Emily M; Delude, Katie

    2017-10-07

    The purpose was to identify off-ice testing variables that correlate to skating and game performance in Division I collegiate women ice hockey players. Twenty female, forward and defensive players (19.95 ± 1.35 yr) were assessed for weight, height, percent fat mass (%FAT), bone mineral density, predicted one repetition maximum (RM) absolute and relative (REL%) bench press (BP) and hex bar deadlift (HDL), lower body explosive power, anaerobic power, countermovement vertical jump (CMJ), maximum inspiratory pressure (MIP), and on-ice repeated skate sprint (RSS) performance. The on-ice RSS test included 6 timed 85.6 m sprints with participants wearing full hockey equipment; fastest time (FT), average time (AT) and fatigue index (FI) for the first length skate (FLS; 10 m) and total length skate (TLS; 85.6 m) were used for analysis. Game performance was evaluated with game statistics: goals, assists, points, plus-minus, and shots on goal (SOG). Correlation coefficients were used to determine relationships. Percent fat mass was positively correlated (p Game performance in women ice hockey players may be enhanced by greater MIP, repeat acceleration ability, and mode-specific training. Faster skating times were associated with lower %FAT. Skating performance in women ice hockey players may be enhanced by improving body composition, anaerobic power, and both lower and upper body strength in off-ice training.

  4. Knowing what to do and doing it : Differences in self-assessed tactical skills of regional, sub-elite, and elite youth field hockey players

    Elferink-Gemser, Marije T.; Kannekens, Rianne; Lyons, Jim; Tromp, Yvonne; Visscher, Chris

    2010-01-01

    To determine whether youth athletes with an oaverageo (regional), ohigho (sub-elite), and overy higho (elite) level of performance differ with respect to their self-assessed tactical skills, 191 youth field hockey players (mean age 15.5 years, s=1.6) completed the Tactical Skills Inventory for

  5. Effectiveness of competitive activity of high class hockey players accounting a level of their self-esteem

    Mikhnov A.P.

    2015-02-01

    Full Text Available Purpose : study the effect of increasing the level of self-esteem on the efficiency of competitive activity of high class players. Material : the study involved sixteen athletes (Atlanta, Moscow region. - Continental Hockey League. Results : it was found that the application of special training self-esteem increases the level of implementation of technical and tactical action games. Number of goals increased by 8.92%, assists - 21.5%, the total number of shots on goal - to 20.02%. Conclusions : it is recommended specialized program correction level of self-esteem from 10 separate studies. Classes have different target setting: habit forming positive attitudes towards themselves, develop skills of active life position, securing high self-esteem. The program is used for two weeks in the preparatory period of training.

  6. Investigation of Positional Differences in Fitness of Male University Ice Hockey Players and the Frequency, Time Spent and Heart Rate of Movement Patterns during Competition

    Joel Jackson

    2017-07-01

    Full Text Available Background:  Men’s university ice hockey has received little scientific attention over the past 30 years, a time in which the traits of the players and the demands of the game have evolved.  Objectives: This study compared the physiological characteristics of university ice hockey players and examined the frequency and duration of the different movement patterns and heart rate (HR responses during competition. Methods: Twenty male ice hockey players from the same team ( age ± SD = 22±2 years underwent a fitness evaluation and were filmed and HR monitored during regular season games. Results: Forwards and defense had similar fitness and only differed on % fatigue index and peak heart during on-ice sprinting (P<0.05. Defense stood, glided and skated backwards more than forwards and forwards skated at a moderate intensity and glided forward more than defense (P<0.05. All players spent the majority of game time gliding forward (60% of the time followed by skating forward at a moderate intensity (17% and standing with little movement (9%. Average HR during the game reached 96 and 92 % and peak HR was 100 and 96 % of maximum in forwards and defense, respectively. Conclusions: Male university hockey players present with a high level of physical fitness in a variety of categories with few differences between forwards and defense. Movement patterns during games suggest that players are performing low to moderate intensity on-ice activities the majority of the time. Paradoxically, HR continues to climb to near maximum during on ice shifts.

  7. The role of visual perception measures used in sports vision programmes in predicting actual game performance in Division I collegiate hockey players.

    Poltavski, Dmitri; Biberdorf, David

    2015-01-01

    Abstract In the growing field of sports vision little is still known about unique attributes of visual processing in ice hockey and what role visual processing plays in the overall athlete's performance. In the present study we evaluated whether visual, perceptual and cognitive/motor variables collected using the Nike SPARQ Sensory Training Station have significant relevance to the real game statistics of 38 Division I collegiate male and female hockey players. The results demonstrated that 69% of variance in the goals made by forwards in 2011-2013 could be predicted by their faster reaction time to a visual stimulus, better visual memory, better visual discrimination and a faster ability to shift focus between near and far objects. Approximately 33% of variance in game points was significantly related to better discrimination among competing visual stimuli. In addition, reaction time to a visual stimulus as well as stereoptic quickness significantly accounted for 24% of variance in the mean duration of the player's penalty time. This is one of the first studies to show that some of the visual skills that state-of-the-art generalised sports vision programmes are purported to target may indeed be important for hockey players' actual performance on the ice.

  8. CATECHOLAMINES AND β2-ADRENOCEPTOR GENE EXPRESSION BEFORE AND AFTER MAXIMAL INCREMENTAL CYCLE TEST IN YOUNG ICE HOCKEY PLAYERS: RELATION TO WORK PERFORMED

    Urszula Mazurek

    2013-04-01

    Full Text Available The aim of this study was to assess the plasma adrenaline and noradrenaline concentrations as well as whole blood β2-adrenoceptor gene (ADRB2 expression in young ice hockey players before and immediately after exercise in relation to performed work. Nineteen Youth National Team ice hockey players were subjected to the maximal incremental cycloergometer exercise. The test was done in the pre-competitive phase of training. Among many parameters the plasma adrenaline and noradrenaline concentrations and ADRB2 gene expression in peripheral blood mononuclear cells (PBMC were determined before and after exercise. The average performed work was 3261.3 ± 558.3 J · kg-1 and maximal oxygen consumption (VO2max for all players was 53.85 ± 3.91 mL · kg-1 min-1. The geometric mean of the ADRB2 gene expression was statistically significantly different before and after exercise (P ≤ 0.05, while adrenaline and noradrenaline levels in plasma significantly increased after exercise. In the analysed group of athletes we found that initial level of plasma noradrenaline correlated with the performed work (r = - 0.55, P < 0.014 and normalized ADRB2 expression before the exercise correlated with the work done by them (r = 0.48, P<0.039. However, no statistically significant correlations were found between the plasma adrenaline or noradrenaline concentrations and ADRB2 gene expression in peripheral blood of the players. The performed work in the maximal incremental exercise test of regularly training young ice hockey players depends on the initial levels of noradrenaline in plasma and ADRB2 mRNA in PBMC.

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

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

    2017-04-04

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

  10. The Effect of the "Zero Tolerance for Head Contact" Rule Change on the Risk of Concussions in Youth Ice Hockey Players.

    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

  11. Multiple Off-Ice Performance Variables Predict On-Ice Skating Performance in Male and Female Division III Ice Hockey Players

    effrey M. Janot, Nicholas M. Beltz, Lance D. Dalleck

    2015-09-01

    Full Text Available The purpose of this study was to determine if off-ice performance variables could predict on-ice skating performance in Division III collegiate hockey players. Both men (n = 15 and women (n = 11 hockey players (age = 20.5 ± 1.4 years participated in the study. The skating tests were agility cornering S-turn, 6.10 m acceleration, 44.80 m speed, modified repeat skate, and 15.20 m full speed. Off-ice variables assessed were years of playing experience, height, weight and percent body fat and off-ice performance variables included vertical jump (VJ, 40-yd dash (36.58m, 1-RM squat, pro-agility, Wingate peak power and peak power percentage drop (% drop, and 1.5 mile (2.4km run. Results indicated that 40-yd dash (36.58m, VJ, 1.5 mile (2.4km run, and % drop were significant predictors of skating performance for repeat skate (slowest, fastest, and average time and 44.80 m speed time, respectively. Four predictive equations were derived from multiple regression analyses: 1 slowest repeat skate time = 2.362 + (1.68 x 40-yd dash time + (0.005 x 1.5 mile run, 2 fastest repeat skate time = 9.762 - (0.089 x VJ - (0.998 x 40-yd dash time, 3 average repeat skate time = 7.770 + (1.041 x 40-yd dash time - (0.63 x VJ + (0.003 x 1.5 mile time, and 4 47.85 m speed test = 7.707 - (0.050 x VJ - (0.01 x % drop. It was concluded that selected off-ice tests could be used to predict on-ice performance regarding speed and recovery ability in Division III male and female hockey players.

  12. Ice hockey injuries.

    Benson, Brian W; Meeuwisse, Willem H

    2005-01-01

    This article reviews the distribution and determinants of injuries reported in the pediatric ice hockey literature, and suggests potential injury prevention strategies and directions for further research. Thirteen electronic databases, the ISI Web of Science, and 'grey literature' databases were searched using a combination of Medical Subject Headings and text words to identify potentially relevant articles. The bibliographies of selected studies were searched to identify additional articles. Studies were selected for review based on predetermined inclusion and exclusion criteria. A comparison between studies on this topic area was difficult due to the variability in research designs, definition of injury, study populations, and measurements used to assess injury. The majority of injuries were sustained during games compared with practices. The two most commonly reported injuries were sprains/strains and contusions. Players competing at the Minor hockey, High School, and Junior levels of competition sustained most of their injuries to the upper extremity, head, and lower extremity, respectively. The primary mechanism of injury was body checking, followed by stick and puck contact. The frequency of catastrophic eye injuries has been significantly reduced with the world-wide mandation of full facial protection for all Minor hockey players. Specific hockey-related injury risk factors are poorly delineated and rarely studied among pediatric ice hockey players leaving large gaps in the knowledge of appropriate prevention strategies. Risk management strategies should be focused at avoiding unnecessary foreseeable risk, and controlling the risks inherent to the sport. Suggestions for injury prevention and future research are discussed.

  13. Vitamin D status and V[combining dot above]O2peak during a skate treadmill graded exercise test in competitive ice hockey players.

    Fitzgerald, John S; Peterson, Ben J; Warpeha, Joseph M; Wilson, Patrick B; Rhodes, Greg S; Ingraham, Stacy J

    2014-11-01

    Vitamin D status has been associated with cardiorespiratory fitness (CRF) in cross-sectional investigations in the general population. Data characterizing the association between 25-hydroxyvitamin D (25(OH)D) concentration and CRF in athletes are lacking. Junior and collegiate ice hockey players were recruited from the Minneapolis, MN (44.9° N), area during the off-season period (May 16-June 28). The purpose of this study was to examine the cross-sectional association between 25(OH)D concentration and CRF in a sample population of competitive ice hockey players. Circulating 25(OH)D level was assessed from a capillary blood sample analyzed using liquid chromatography-tandem mass spectrometry. V[Combining Dot Above]O2peak during a skate treadmill graded exercise test (GXT) was used to assess CRF. Data on both 25(OH)D concentration and V[Combining Dot Above]O2peak were available for 52 athletes. Insufficient 25(OH)D concentrations were found in 37.7% of the athletes (skate treadmill GXT.

  14. Educational strategies used in increasing fluid intake and enhancing hydration status in field hockey players preparing for competition in a hot and humid environment: a case study.

    Dabinett, J A; Reid, K; James, N

    2001-09-01

    The purpose of the present study was to develop a hydration strategy for use by female English field hockey players at the 1998 Commonwealth Games in Malaysia. An additional aim was to initiate the process of acclimation. Fifteen elite players, mean age (+/-SEM) 24.1 +/- 1.19 years, height 1.67 +/- 0.01 m, and body mass 62.8 +/- 1.76 kg, took part in a 5-day training camp immediately prior to departure for the Games. In order to develop the hydration strategy, training took place under similar environmental conditions to those to be experienced in Malaysia (i.e., 32 degrees C, 80% humidity). Acclimation training consisted of 30-50 min of either continuous, low intensity cycling or high intensity intermittent cycling, which more closely replicated the pattern of activity in field hockey. Body mass measures taken each morning, and pre and post training, together with urine color measures, were used to assess hydration status. Pre-loading with up to 1 L of a 3% carbohydrate-electrolyte solution or water immediately prior to acclimation training, as well as regular drinks throughout, ensured that players avoided significant dehydration, with percent body mass changes ranging from -0.34% to +4.24% post training. Furthermore, the protocol used was sufficient to initiate the process of acclimation as demonstrated by a significant reduction in exercising heart rate and core temperature at all time points by days 4 and 5. In conclusion, although labor intensive and time consuming, the camp was successful in developing a hydration strategy that players were able to utilize once at the Games.

  15. Multiple Off-Ice Performance Variables Predict On-Ice Skating Performance in Male and Female Division III Ice Hockey Players.

    Janot, Jeffrey M; Beltz, Nicholas M; Dalleck, Lance D

    2015-09-01

    The purpose of this study was to determine if off-ice performance variables could predict on-ice skating performance in Division III collegiate hockey players. Both men (n = 15) and women (n = 11) hockey players (age = 20.5 ± 1.4 years) participated in the study. The skating tests were agility cornering S-turn, 6.10 m acceleration, 44.80 m speed, modified repeat skate, and 15.20 m full speed. Off-ice variables assessed were years of playing experience, height, weight and percent body fat and off-ice performance variables included vertical jump (VJ), 40-yd dash (36.58m), 1-RM squat, pro-agility, Wingate peak power and peak power percentage drop (% drop), and 1.5 mile (2.4km) run. Results indicated that 40-yd dash (36.58m), VJ, 1.5 mile (2.4km) run, and % drop were significant predictors of skating performance for repeat skate (slowest, fastest, and average time) and 44.80 m speed time, respectively. Four predictive equations were derived from multiple regression analyses: 1) slowest repeat skate time = 2.362 + (1.68 x 40-yd dash time) + (0.005 x 1.5 mile run), 2) fastest repeat skate time = 9.762 - (0.089 x VJ) - (0.998 x 40-yd dash time), 3) average repeat skate time = 7.770 + (1.041 x 40-yd dash time) - (0.63 x VJ) + (0.003 x 1.5 mile time), and 4) 47.85 m speed test = 7.707 - (0.050 x VJ) - (0.01 x % drop). It was concluded that selected off-ice tests could be used to predict on-ice performance regarding speed and recovery ability in Division III male and female hockey players. Key pointsThe 40-yd dash (36.58m) and vertical jump tests are significant predictors of on-ice skating performance specific to speed.In addition to 40-yd dash and vertical jump, the 1.5 mile (2.4km) run for time and percent power drop from the Wingate anaerobic power test were also significant predictors of skating performance that incorporates the aspect of recovery from skating activity.Due to the specificity of selected off-ice variables as predictors of on-ice performance, coaches can

  16. The Effect of Teaching Games of Understanding as a Coaching Instruction had on Adjust, Cover and Heart Rate among Malaysian and Indian Junior Hockey Players

    Sanmuga Nathan

    2017-06-01

    Full Text Available The field hockey coaching process across both Malaysia and India favours a traditional, coach-centred approach of mastering technical skills in terms of game play parameters, fitness, intensity, and load training, whereas a tactical- and player-centred pedagogical approach still takes a backseat. On the other hand, the Teaching Games for Understanding (TGfU model offers tactical-cognitive instruction and is gaining international recognition for its ability to produce intelligent players via a problem-solving approach in game play. Therefore, the purpose of this quasi-experimental study was to investigate the effect of TGfU compared to skill mastery instruction, termed as Skill Drill Technical (SDT, among Malaysian and Indian elite junior hockey players in term of the game play attributes of adjust and cover in 5 vs. 5 small-sided game play and game play intensity via heart rate (HR at different points of game play. A total of n = 60 players with an average age of 15 ± 1.03 was selected via simple random sampling from both countries involved in this study and assigned equally to groups, with 15 per group for TGfU and for SDT across Malaysia and India. Gathered data were analysed using the ANOVA and ANCOVA techniques. Findings indicated that there were no significant differences for adjust in 5 vs. 5 game play between TGfU and SDT across Malaysia and India after the intervention. For cover, there was significant improvement for Malaysian players using the TGfU model compared to SDT. In contrast, there was no significant difference between these two models among the Indian players after the intervention. There was significant difference between these two models in terms of warm-up HR across the two countries, and HR was higher via TGfU. For HR immediately after the 5 vs. 5 game play intervention and HR after three minutes’ recovery, Indian players with TGfU recorded a higher and significant difference compared to SDT. However, findings indicated

  17. The Effect of Teaching Games of Understanding as a Coaching Instruction had on Adjust, Cover and Heart Rate among Malaysian and Indian Junior Hockey Players.

    Nathan, Sanmuga

    2017-06-20

    The field hockey coaching process across both Malaysia and India favours a traditional, coach-centred approach of mastering technical skills in terms of game play parameters, fitness, intensity, and load training, whereas a tactical- and player-centred pedagogical approach still takes a backseat. On the other hand, the Teaching Games for Understanding (TGfU) model offers tactical-cognitive instruction and is gaining international recognition for its ability to produce intelligent players via a problem-solving approach in game play. Therefore, the purpose of this quasi-experimental study was to investigate the effect of TGfU compared to skill mastery instruction, termed as Skill Drill Technical (SDT), among Malaysian and Indian elite junior hockey players in term of the game play attributes of adjust and cover in 5 vs. 5 small-sided game play and game play intensity via heart rate (HR) at different points of game play. A total of n = 60 players with an average age of 15 ± 1.03 was selected via simple random sampling from both countries involved in this study and assigned equally to groups, with 15 per group for TGfU and for SDT across Malaysia and India. Gathered data were analysed using the ANOVA and ANCOVA techniques. Findings indicated that there were no significant differences for adjust in 5 vs. 5 game play between TGfU and SDT across Malaysia and India after the intervention. For cover, there was significant improvement for Malaysian players using the TGfU model compared to SDT. In contrast, there was no significant difference between these two models among the Indian players after the intervention. There was significant difference between these two models in terms of warm-up HR across the two countries, and HR was higher via TGfU. For HR immediately after the 5 vs. 5 game play intervention and HR after three minutes' recovery, Indian players with TGfU recorded a higher and significant difference compared to SDT. However, findings indicated no significant

  18. Comparison of Concussion Rates Between NCAA Division I and Division III Men's and Women's Ice Hockey Players.

    Rosene, John M; Raksnis, Bryan; Silva, Brie; Woefel, Tyler; Visich, Paul S; Dompier, Thomas P; Kerr, Zachary Y

    2017-09-01

    Examinations related to divisional differences in the incidence of sports-related concussions (SRC) in collegiate ice hockey are limited. To compare the epidemiologic patterns of concussion in National Collegiate Athletic Association (NCAA) ice hockey by sex and division. Descriptive epidemiology study. A convenience sample of men's and women's ice hockey teams in Divisions I and III provided SRC data via the NCAA Injury Surveillance Program during the 2009-2010 to 2014-2015 academic years. Concussion counts, rates, and distributions were examined by factors including injury activity and position. Injury rate ratios (IRRs) and injury proportion ratios (IPRs) with 95% confidence intervals (CIs) were used to compare concussion rates and distributions, respectively. Overall, 415 concussions were reported for men's and women's ice hockey combined. The highest concussion rate was found in Division I men (0.83 per 1000 athlete-exposures [AEs]), followed by Division III women (0.78/1000 AEs), Division I women (0.65/1000 AEs), and Division III men (0.64/1000 AEs). However, the only significant IRR was that the concussion rate was higher in Division I men than Division III men (IRR = 1.29; 95% CI, 1.02-1.65). The proportion of concussions from checking was higher in men than women (28.5% vs 9.4%; IPR = 3.02; 95% CI, 1.63-5.59); however, this proportion was higher in Division I women than Division III women (18.4% vs 1.8%; IPR = 10.47; 95% CI, 1.37-79.75). The proportion of concussions sustained by goalkeepers was higher in women than men (14.2% vs 2.9%; IPR = 4.86; 95% CI, 2.19-10.77), with findings consistent within each division. Concussion rates did not vary by sex but differed by division among men. Checking-related concussions were less common in women than men overall but more common in Division I women than Division III women. Findings highlight the need to better understand the reasons underlying divisional differences within men's and women's ice hockey and the

  19. Hip abduction-adduction strength and one-leg hop tests: test-retest reliability and relationship to function in elite ice hockey players.

    Kea, J; Kramer, J; Forwell, L; Birmingham, T

    2001-08-01

    Single group, test-retest. To determine: (1) hip abduction and adduction torques during concentric and eccentric muscle actions, (2) medial and lateral one-leg hop distances, (3) the test-retest reliability of these measurements, and (4) the relationship between isokinetic measures of hip muscle strength and hop distances in elite ice hockey players. The skating motion used in ice hockey requires strong contractions of the hip and knee musculature. However, baseline scores for hip strength and hop distances, their test-retest reliability, and measures of the extent to which these tests are related for this population are not available. The dominant leg of 27 men (mean age 20 +/- 3 yrs) was tested on 2 occasions. Hip abduction and adduction movements were completed at 60 degrees.s(-1) angular velocity, with the subject lying on the non-test side and the test leg moving vertically in the subject's coronal plane. One-leg hops requiring jumping from and landing on the same leg without losing balance were completed in the medial and lateral directions. Hip adduction torques were significantly greater than abduction torques during both concentric and eccentric muscle actions, while no significant difference was observed between medial and lateral hop distances. Although hop test scores produced excellent ICCs (> 0.75) when determined using scores on 1 occasion, torques needed to be averaged over 2 test occasions to reach this level. Correlations between the strength and hop tests ranged from slight to low (r = -0.26 to 0.27) and were characterized by wide 95% confidence intervals (-0.54 to 0.61). Isokinetic tests of hip abduction and adduction did not provide a strong indication of performance during sideways hop tests. Although isokinetic tests can provide a measure of muscular strength under specific test conditions, they should not be relied upon as a primary indicator of functional abilities or readiness to return to activity.

  20. Changes of the morphological characteristics in a professional ice hockey player with regard to the eight week intensive fitness training: case study

    Sigmund Martin

    2013-01-01

    Full Text Available The present study deals with monitoring the changes of the morphological characteristics in a professional hockey player (NHL aged 22.5 years with regard to the eight weeks intensive fitness training. Fitness training occurred off the ice surface. To determine the body composition, the method of BIA and anthropometric procedure is used (Matiegka, Pařízková. Measurements were carried out in accordance with the recommended national and international standards. An effect size of the differences in the selected individual values measured at different times was assessed using 95% of confidence interval. Significant changes occur primarily at the level of body composition. Overall, the increase in fat free mass was 4 kg to the weight 79.3 kg (BIA. Representation of muscle increased from 51.4% to 54.5% (Matiegka. In absolute terms it is the increase in muscle from 47.1 kg to 49.9 kg. Body fat percentage decreased from 12.9% to 9.7% (Matiegka. This represents a reduction of 2.9 kg. There is no change at the level of skeletal and residual fractions. With regard to the eight week fitness training the major morhpohogical changes (80-90% are experienced during the first half of the training (4 weeks. The survey results are of immediate use in the professional practice of the monitored player. It allows specific modifications to the training of the monitored player as well as other cooperating individuals in the chosen specialization.

  1. Effect of manual therapy versus proprioceptive neuromuscular facilitation in dynamic balance, mobility and flexibility in field hockey players. A randomized controlled trial.

    Espí-López, Gemma V; López-Martínez, Susana; Inglés, Marta; Serra-Añó, Pilar; Aguilar-Rodríguez, Marta

    2018-04-22

    To compare the effectiveness of a specific Manual Therapy (MT) protocol applied to field hockey players (FHP), versus a Proprioceptive Neuromuscular Facilitation (PNF) protocol, in the improvement of dynamic balance, active range of movement and lumbar flexibility one-week and four-weeks after the treatment. Randomized controlled trial. Participants were assigned to 2 groups: MT and PNF. 30 min' sessions were performed once a week for three weeks. Three evaluations were performed: basal, one-week and four-weeks post-treatment. University of Valencia (Spain). 22 in MT group and 20 in PNF group. Dynamic Balance, measured with Star Excursion Balance Test; Active Range of Motion (ROM), using a manual goniometer and Lumbar Flexibility, assessed with Fingertip-to-floor test. Both groups significantly improved in lateral and medial dynamic balance one-week post-treatment (p < 0.05); but the improvement in the MT group lasted until the fourth-week after treatment in both reaches (lateral and medial) (p < 0.05). MT group also obtained significant improvements in dorsal flexion of the ankle in the fourth-week post-treatment (p < 0.05) and in lumbar flexibility one-week post-treatment (p < 0.05). MT and PNF improve dynamic balance one-week post-treatment; however, the improvement obtained through MT is maintained four-weeks later. Only MT improves dorsal flexion of the ankle four-weeks post-treatment and lumbar flexibility one-week post-treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Updating the Skating Multistage Aerobic Test and Correction for V[Combining Dot Above]O2max Prediction Using a New Skating Economy Index in Elite Youth Ice Hockey Players.

    Allisse, Maxime; Bui, Hung Tien; Léger, Luc; Comtois, Alain-Steve; Leone, Mario

    2018-05-07

    Allisse, M, Bui, HT, Léger, L, Comtois, A-S, and Leone, M. Updating the skating multistage aerobic test and correction for V[Combining Dot Above]O2max prediction using a new skating economy index in elite youth ice hockey players. J Strength Cond Res XX(X): 000-000, 2018-A number of field tests, including the skating multistage aerobic test (SMAT), have been developed to predict V[Combining Dot Above]O2max in ice hockey players. The SMAT, like most field tests, assumes that participants who reach a given stage have the same oxygen uptake, which is not usually true. Thus, the objectives of this research are to update the V[Combining Dot Above]O2 values during the SMAT using a portable breath-by-breath metabolic analyzer and to propose a simple index of skating economy to improve the prediction of oxygen uptake. Twenty-six elite hockey players (age 15.8 ± 1.3 years) participated in this study. The oxygen uptake was assessed using a portable metabolic analyzer (K4b) during an on-ice maximal shuttle skate test. To develop an index of skating economy called the skating stride index (SSI), the number of skating strides was compiled for each stage of the test. The SMAT enabled the prediction of the V[Combining Dot Above]O2max (ml·kg·min) from the maximal velocity (m·s) and the SSI (skating strides·kg) using the following regression equation: V[Combining Dot Above]O2max = (14.94 × maximal velocity) + (3.68 × SSI) - 24.98 (r = 0.95, SEE = 1.92). This research allowed for the update of the oxygen uptake values of the SMAT and proposed a simple measure of skating efficiency for a more accurate evaluation of V[Combining Dot Above]O2max in elite youth hockey players. By comparing the highest and lowest observed SSI scores in our sample, it was noted that the V[Combining Dot Above]O2 values can vary by up to 5 ml·kg·min. Our results suggest that skating economy should be included in the prediction of V[Combining Dot Above]O2max to improve prediction accuracy.

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

    Steingard, S A

    1993-04-01

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

  4. Incidence of hockey ankle injuries in Kwa-Zulu Natal, South Africa ...

    ankle injuries amongst hockey players was 26.41%. The most frequent ankle injury sustained by male adolescent hockey players was an inversion ankle sprain (84.62% of the 26.41% injured subjects of the sample cohort). The mechanisms of ankle injuries were attributed to rapid rotational movements of the ankle joint ...

  5. NHL Heavyweights: Narratives of Violence and Masculinity in Ice Hockey

    Tjønndal Anne

    2016-06-01

    Full Text Available Sport is often considered a masculine area of social life, and few sports are more commonly associated with traditional norms of masculinity than ice hockey. Ice hockey is played with a great level of intensity and body contact. This is true for both men and women’s hockey. However, men’s ice hockey in particular has been subjected to criticism for its excessive violence. Sport has also been analyzed as an arena where boys and men learn masculine values, relations, and rituals, and is often linked to orthodox masculinity in particular. Tolerance for gender diversity and diverse forms of masculinity has generally increased during the last 30 years. However, orthodox masculinity seems to maintain a dominate position in sports, particularly in hyper-masculine sports such as ice hockey. In this article, narratives of masculinity and violence in professional ice hockey are a central focus. Through a narrative analysis of the biographies of two former National Hockey League (NHL players, Bob Probert and Derek Boogaard, this article explores how narratives of masculinity and violence among hockey players have been described and how these narratives tell stories of the interplay between masculinity and violence in modern sport. The analysis illustrates how the narratives of the lives and careers of these athletes provide insight into the many personal risks and implications athletes in highly masculine sporting environments face. The analysis also illustrates how the common acceptance (and sometimes encouragement of player violence and ‘violence against the self’ in ice hockey has led to many broken bodies, lives, and careers among professional male athletes.

  6. Analysis of High-Intensity Skating in Top-Class Ice Hockey Match-Play in Relation to Training Status and Muscle Damage

    Lignell, Erik; Fransson, Dan; Krustrup, Peter

    2018-01-01

    of training status. Male ice-hockey players (n = 36) from the National Hockey League participated. Match analysis was performed during a game and physical capacity was assessed by a submaximal Yo-Yo Intermittent Recovery Ice-hockey test, level 1 (YYIR1-IHSUB). Venous blood samples were collected 24-hour post...

  7. Gender in ice hockey: women in a male territory.

    Gilenstam, K; Karp, S; Henriksson-Larsén, K

    2008-04-01

    This study investigates how female ice hockey players describe and explain their situation within as well as outside their sport. Information was obtained by semi-structured interviews with female ice hockey players. The results were analyzed in a gender perspective where the main starting point was the concepts of different levels of power relations in society developed by Harding and applied to sports by Kolnes (the symbolic, structural, and individual level). The study shows that the players appeared to share the traditional views of men and women. They also described gender differences in terms of financial and structural conditions as well as differences in ice hockey history. Even though the players described structural inequalities, they were quite content with their situation and the differences in conditions were not considered when they explained the gender differences in ice hockey performance. At the individual level, the players considered themselves different from other women and appeared to share the traditional views of femininity and masculinity. It has been suggested that performance of a sport traditionally associated with the other sex might alter the traditional view of men and women; however, our results lend little support to this suggestion.

  8. Carbon Monoxide Exposure in Youth Ice Hockey.

    Macnow, Theodore; Mannix, Rebekah; Meehan, William P

    2017-11-01

    To examine the effect of ice resurfacer type on carboxyhemoglobin levels in youth hockey players. We hypothesized that players in arenas with electric resurfacers would have normal, stable carboxyhemoglobin levels during games, whereas those in arenas with internal combustion engine (IC) resurfacers would have an increase in carboxyhemoglobin levels. Prospective cohort study. Enclosed ice arenas in the northeastern United States. Convenience sample of players aged 8 to 18 years old in 16 games at different arenas. Eight arenas (37 players) used an IC ice resurfacer and 8 arenas (36 players) an electric resurfacer. Carboxyhemoglobin levels (SpCO) were measured using a pulse CO-oximeter before and after the game. Arena air was tested for carbon monoxide (CO) using a metered gas detector. Players completed symptom questionnaires. The change in SpCO from pregame to postgame was compared between players at arenas with electric versus IC resurfacers. Carbon monoxide was present at 6 of 8 arenas using IC resurfacers, levels ranged from 4 to 42 parts per million. Carbon monoxide was not found at arenas with electric resurfacers. Players at arenas with IC resurfacers had higher median pregame SpCO levels compared with those at electric arenas (4.3% vs 1%, P carboxyhemoglobin during games and have elevated baseline carboxyhemoglobin levels compared with players at arenas with electric resurfacers. Electric resurfacers decrease the risk of CO exposure.

  9. Creating a goaltending development manual for Belgium Ice Hockey

    Guay, Eddy

    2014-01-01

    The objective of the thesis and was to create a goalie development manual for the Royal Belgian Ice Hockey Federation (RBIHF). The manual will provide goalies and coaches a guide for developing players in the position. The manual aims to provide a technical resources for goalies and coaches on the skills that goalies need to focus on to allow them to improve their play. ! “The backbone of a hockey team”or “The most important position in sports” are two of many phrases that i...

  10. Hockey lines for simulation-based learning.

    Topps, David; Ellaway, Rachel; Kupsh, Christine

    2015-06-01

    Simulation-based health professional education is often limited in accommodating large numbers of students. Most organisations do not have enough simulation suites or staff to support growing demands. We needed to find ways to make simulation sessions more accommodating for larger groups of learners, so that more than a few individuals could be active in a simulation scenario at any one time. Moreover, we needed to make the experience meaningful for all participating learners. We used the metaphor of (ice) hockey lines and substitution 'on the fly' to effectively double the numbers of learners that can be actively engaged at once. Team players must communicate clearly, and observe keenly, so that currently playing members understand what is happening from moment to moment and incoming substitutes can take over their roles seamlessly. Most organisations do not have enough simulation suites or staff to support growing demands We found that this hockey lines approach to simulation-based team scenarios will raise learners' levels of engagement, reinforce good crew resource management (CRM) practices, enhance closed-loop communication, and help learners to understand their cognitive biases and limitations when working in high-pressure situations. During our continuing refinement of the hockey-lines approach, we developed a number of variations on the basic activity model, with various benefits and applications. Both students and teachers have been enthusiastically positive about this approach when it was introduced at our various courses and participating institutions. © 2015 John Wiley & Sons Ltd.

  11. Physiological, physical and on-ice performance criteria for selection of elite ice hockey teams

    R Roczniok

    2016-01-01

    Full Text Available The purpose of this study was to examine physiological and physical determinants of ice-hockey performance in order to assess their impact on the result during a selection for ice hockey. A total of 42 ice hockey players took part in the selection camp. At the end of the camp 20 best players were selected by team of expert coaches to the ice hockey team and created group G1, while the second group (G2 consisted of not selected players (non-successful group Evaluation of goodness of fit of the model to the data was based on the Hosmer Lemeshow test Ice hockey players selected to the team were taller 181.95±4.02 cm, had lower % body fat 13.17±3.17%, a shorter time to peak power 2.47±0.35 s , higher relative peak power 21.34±2.41 W • kg-1 and higher relative total work 305.18±28.41 J • kg-1. The results of the aerobic capacity test showed significant differences only in case of two variables. Ice hockey players in the G1 had higher VO2max 4.07±0.31 l • min-1 values than players in the G2 as well as ice hockey players in G1 showed a higher level of relative VO2max 51.75±2.99 ml • min-1 • kg-1 than athletes in G2. Ice hockey players selected to the team (G1 performed better in the 30 m Forwards Sprint 4.28±0.31 s; 6x9 Turns 12.19±0.75 s; 6x9 stops 12.79±0.49 s and Endurance test (6x30 m stops 32.01±0.80 s than players in G2. The logistic regression model showed that the best predictors of success in the recruitment process of top level ice hockey players were time to peak power, relative peak power, VO2max and 30 m sprint forwards on ice. On the basis of the constructed predictive logistic regression model it will be possible to determine the probability of success of the athletes during following the selection processes to the team.

  12. Bodychecking rules and concussion in elite hockey.

    Laura Donaldson

    Full Text Available Athletes participating in contact sports such as ice hockey are exposed to a high risk of suffering a concussion. We determined whether recent rule changes regulating contact to the head introduced in 2010-11 and 2011-12 have been effective in reducing the incidence of concussion in the National Hockey League (NHL. A league with a longstanding ban on hits contacting the head, the Ontario Hockey League (OHL, was also studied. A retrospective study of NHL and OHL games for the 2009-10 to 2011-12 seasons was performed using official game records and team injury reports in addition to other media sources. Concussion incidence over the 3 seasons analyzed was 5.23 per 100 NHL regular season games and 5.05 per 100 OHL regular season games (IRR 1.04; 95% CI 1.01, 1.50. When injuries described as concussion-like or suspicious of concussion were included, incidences rose to 8.8 and 7.1 per 100 games respectively (IRR 1.23; 95% CI 0.81, 1.32. The number of NHL concussions or suspected concussions was lower in 2009-10 than in 2010-11 (IRR 0.61; 95% CI 0.45, 0.83, but did not increase from 2010-11 to 2011-12 (IRR 1.05; 95% CI 0.80, 1.38. 64.2% of NHL concussions were caused by bodychecking, and only 28.4% of concussions and 36.8% of suspected concussions were caused by illegal incidents. We conclude that rules regulating bodychecking to the head did not reduce the number of players suffering concussions during NHL regular season play and that further changes or stricter enforcement of existing rules may be required to minimize the risk of players suffering these injuries.

  13. Evaluation, management and prevention of lower extremity youth ice hockey injuries

    Popkin CA

    2016-11-01

    Full Text Available Charles A Popkin,1 Brian M Schulz,2 Caroline N Park,1 Thomas S Bottiglieri,1 T Sean Lynch1 1Department of Orthopedic Surgery, Center for Shoulder, Elbow and Sports Medicine at Columbia University, New York, NY, 2Kerlan‑Jobe Orthopedic Clinic, Los Angeles, CA, USA Abstract: Ice hockey is a fast-paced sport played by increasing numbers of children and adolescents in North America and around the world. Requiring a unique blend of skill, finesse, power and teamwork, ice hockey can become a lifelong recreational activity. Despite the rising popularity of the sport, there is ongoing concern about the high frequency of musculoskeletal injury associated with participation in ice hockey. Injury rates in ice hockey are among the highest in all competitive sports. Numerous research studies have been implemented to better understand the risks of injury. As a result, rule changes were adopted by the USA Hockey and Hockey Canada to raise the minimum age at which body checking is permitted to 13–14 years (Bantam level from 11–12 years (Pee Wee. Continuing the education of coaches, parents and players on rules of safe play, and emphasizing the standards for proper equipment use are other strategies being implemented to make the game safer to play. The objective of this article was to review the evaluation, management and prevention of common lower extremity youth hockey injuries. Keywords: youth hockey, body checking, injury prevention, femoroacetabular impingement, apophyseal avulsions

  14. Aggression, Violence and Injury in Minor League Ice Hockey: Avenues for Prevention of Injury.

    Michael D Cusimano

    Full Text Available In North America, more than 800,000 youth are registered in organized ice hockey leagues. Despite the many benefits of involvement, young players are at significant risk for injury. Body-checking and aggressive play are associated with high frequency of game-related injury including concussion. We conducted a qualitative study to understand why youth ice hockey players engage in aggressive, injury-prone behaviours on the ice.Semi-structured interviews were conducted with 61 minor ice hockey participants, including male and female players, parents, coaches, trainers, managers and a game official. Players were aged 13-15 playing on competitive body checking teams or on non-body checking teams. Interviews were manually transcribed, coded and analyzed for themes relating to aggressive play in minor ice hockey.Parents, coaches, teammates and the media exert a large influence on player behavior. Aggressive behavior is often reinforced by the player's social environment and justified by players to demonstrate loyalty to teammates and especially injured teammates by seeking revenge particularly in competitive, body-checking leagues. Among female and male players in non-body checking organizations, aggressive play is not reinforced by the social environment. These findings are discussed within the framework of social identity theory and social learning theory, in order to understand players' need to seek revenge and how the social environment reinforces aggressive behaviors.This study provides a better understanding of the players' motivations and environmental influences around aggressive and violent play which may be conducive to injury. The findings can be used to help design interventions aimed at reducing aggression and related injuries sustained during ice hockey and sports with similar cultures and rules.

  15. Aggression, Violence and Injury in Minor League Ice Hockey: Avenues for Prevention of Injury.

    Cusimano, Michael D; Ilie, Gabriela; Mullen, Sarah J; Pauley, Christopher R; Stulberg, Jennifer R; Topolovec-Vranic, Jane; Zhang, Stanley

    2016-01-01

    In North America, more than 800,000 youth are registered in organized ice hockey leagues. Despite the many benefits of involvement, young players are at significant risk for injury. Body-checking and aggressive play are associated with high frequency of game-related injury including concussion. We conducted a qualitative study to understand why youth ice hockey players engage in aggressive, injury-prone behaviours on the ice. Semi-structured interviews were conducted with 61 minor ice hockey participants, including male and female players, parents, coaches, trainers, managers and a game official. Players were aged 13-15 playing on competitive body checking teams or on non-body checking teams. Interviews were manually transcribed, coded and analyzed for themes relating to aggressive play in minor ice hockey. Parents, coaches, teammates and the media exert a large influence on player behavior. Aggressive behavior is often reinforced by the player's social environment and justified by players to demonstrate loyalty to teammates and especially injured teammates by seeking revenge particularly in competitive, body-checking leagues. Among female and male players in non-body checking organizations, aggressive play is not reinforced by the social environment. These findings are discussed within the framework of social identity theory and social learning theory, in order to understand players' need to seek revenge and how the social environment reinforces aggressive behaviors. This study provides a better understanding of the players' motivations and environmental influences around aggressive and violent play which may be conducive to injury. The findings can be used to help design interventions aimed at reducing aggression and related injuries sustained during ice hockey and sports with similar cultures and rules.

  16. Adolescent perspectives of the recreational ice hockey food environment and influences on eating behaviour revealed through photovoice.

    Caswell, M Susan; Hanning, Rhona M

    2018-05-01

    Unhealthy dietary behaviours are prevalent among adolescents. This might relate, in part, to obesogenic environments, including recreation food facilities. The REFRESH Study (Recreation Environment and Food Research: Experiences from Hockey) aimed to explore, from the perspectives of adolescent ice hockey players and parents, broad social and physical environmental influences on adolescent food behaviours associated with hockey participation. Players used photovoice to describe their food experiences in relation to ice hockey. The approach included photos, individual interviews and focus groups. Exemplar photographs were exhibited for stakeholders, including five parents who were interviewed. Interview and focus group transcripts were thematically analysed. Recreational ice hockey environment, Ontario, Canada, 2015-16. Ice hockey players (n 24) aged 11-15 years recruited from five leagues. Dominant influences among players included: their perceived importance of nutrients (e.g. protein) or foods (e.g. chocolate milk) for performance and recovery; marketing and branding (e.g. the pro-hockey aura of Tim Horton's®, Canada's largest quick-service restaurant); social aspects of tournaments and team meals; and moral values around 'right' and 'wrong' food choices. Both players and parents perceived recreational facility food options as unhealthy and identified that travel and time constraints contributed to less healthy choices. Results indicate recreation facilities are only one of a range of environments that influence eating behaviours of adolescent ice hockey players. Players' susceptibility to advertising/brand promotion and the value of healthy food choices for performance are findings that can inform policy and interventions to support healthy environments and behaviours.

  17. Oliver Sacks: Our Correspondence About Twins/Twin Research: Vanishing Twins Syndrome; Discordant Sex in MZ Twins; Pregnancy Outcomes in IVF and ICSI Conceived Twins/Print and Media: Superfetated Twins; Twins Discordant for Smoking; Twins in Fashion; Yale University Twin Hockey Players; Conjoined Twin-Visiting Professor.

    Segal, Nancy L

    2017-08-01

    The late neurologist and author, Oliver Sacks, published an insightful 1986 review of Marjorie Wallace's book, The Silent Twins, in the New York Times. Taking exception to his assertion about Sir Francis Galton, I wrote a letter to the Times' editor. The letter was unpublished, but it brought a wonderful response from Sacks himself that is reproduced and examined. Next, brief reviews of twin research concerning the vanishing twin syndrome (VTS), discordant sex in a monozygotic (MZ) twin pair, and multiple pregnancy outcomes from assisted reproductive technology (ART) are presented. This section is followed by popular coverage of superfetated twins, smoking-discordant co-twins, twins in fashion, Yale University twin hockey players, and a visiting professor who was a conjoined twin.

  18. Common Ice Hockey Injuries and Treatment: A Current Concepts Review.

    Mosenthal, William; Kim, Michael; Holzshu, Robert; Hanypsiak, Bryan; Athiviraham, Aravind

    Injuries are common in ice hockey, a contact sport where players skate at high speeds on a sheet of ice and shoot a vulcanized rubber puck in excess of one hundred miles per hour. This article reviews the diagnoses and treatment of concussions, injuries to the cervical spine, and lower and upper extremities as they pertain to hockey players. Soft tissue injury of the shoulder, acromioclavicular joint separation, glenohumeral joint dislocation, clavicle fractures, metacarpal fractures, and olecranon bursitis are discussed in the upper-extremity section of the article. Lower-extremity injuries reviewed in this article include adductor strain, athletic pubalgia, femoroacetabular impingement, sports hernia, medial collateral and anterior cruciate ligament tears, skate bite, and ankle sprains. This review is intended to aid the sports medicine physician in providing optimal sports-specific care to allow their athlete to return to their preinjury level of performance.

  19. Hypothenar hammer syndrome from ice hockey stick-handling.

    Zayed, Mohamed A; McDonald, Joey; Tittley, Jacques G

    2013-11-01

    Ulnar artery thrombosis and hypothenar hammer syndrome are rare vascular complications that could potentially occur with repeated blows or trauma to the hand. Although initially reported as an occupational hazard among laborers and craftsmen, it has been observed more recently among recreationalists and athletes. Until now, it has never been reported as a complication in ice hockey players. In this case report, a 26-year-old Canadian professional ice hockey player presented with acute dominant right hand paleness, coolness, and pain with hand use. The patient used a wooden hockey stick with a large knob of tape at the end of the handle, which he regularly gripped in the palm of his right hand to help with face-offs and general stick-handling. Sonographic evaluation demonstrated no arterial flow in the distal right ulnar artery distribution, and ulnar artery occlusion with no aneurysmal degeneration was confirmed by magnetic resonance angiogram. Intraarterial thrombolytic therapy was initiated, and subsequent serial angiograms demonstrated significant improvement in distal ulnar artery flow as well as recanalization of right hand deep palmar arch and digital arteries. The patient's symptoms resolved, and he was maintained on therapeutic anticoagulation for 3 months prior to returning to playing ice hockey professionally, but with a padded glove and no tape knob at the handle tip. This case highlights a unique presentation of hockey stick-handling causing ulnar artery thrombosis that was likely from repeated palmar hypothenar trauma. Appropriate diagnostic imaging, early intraarterial thrombolysis, and postoperative surveillance and follow-up were crucial for the successful outcome in this patient. Copyright © 2013 Elsevier Inc. All rights reserved.

  20. Head-impact mechanisms in men's and women's collegiate ice hockey.

    Wilcox, Bethany J; Machan, Jason T; Beckwith, Jonathan G; Greenwald, Richard M; Burmeister, Emily; Crisco, Joseph J

    2014-01-01

    Concussion injury rates in men's and women's ice hockey are reported to be among the highest of all collegiate sports. Quantification of the frequency of head impacts and the magnitude of head acceleration as a function of the different impact mechanisms (eg, head contact with the ice) that occur in ice hockey could provide a better understanding of this high injury rate. To quantify and compare the per-game frequency and magnitude of head impacts associated with various impact mechanisms in men's and women's collegiate ice hockey players. Cohort study. Collegiate ice hockey rink. Twenty-three men and 31 women from 2 National Collegiate Athletic Association Division I ice hockey teams. We analyzed magnitude and frequency (per game) of head impacts per player among impact mechanisms and between sexes using generalized mixed linear models and generalized estimating equations to account for repeated measures within players. Participants wore helmets instrumented with accelerometers to allow us to collect biomechanical measures of head impacts sustained during play. Video footage from 53 games was synchronized with the biomechanical data. Head impacts were classified into 8 categories: contact with another player; the ice, boards or glass, stick, puck, or goal; indirect contact; and contact from celebrating. For men and women, contact with another player was the most frequent impact mechanism, and contact with the ice generated the greatest-magnitude head accelerations. The men had higher per-game frequencies of head impacts from contact with another player and contact with the boards than did the women (P < .001), and these impacts were greater in peak rotational acceleration (P = .027). Identifying the impact mechanisms in collegiate ice hockey that result in frequent and high-magnitude head impacts will provide us with data that may improve our understanding of the high rate of concussion in the sport and inform injury-prevention strategies.

  1. Reducing injury risk from body checking in boys' youth ice hockey.

    Brooks, Alison; Loud, Keith J; Brenner, Joel S; Demorest, Rebecca A; Halstead, Mark E; Kelly, Amanda K Weiss; Koutures, Chris G; LaBella, Cynthia R; LaBotz, Michele; Martin, Stephanie S; Moffatt, Kody

    2014-06-01

    Ice hockey is an increasingly popular sport that allows intentional collision in the form of body checking for males but not for females. There is a two- to threefold increased risk of all injury, severe injury, and concussion related to body checking at all levels of boys' youth ice hockey. The American Academy of Pediatrics reinforces the importance of stringent enforcement of rules to protect player safety as well as educational interventions to decrease unsafe tactics. To promote ice hockey as a lifelong recreational pursuit for boys, the American Academy of Pediatrics recommends the expansion of nonchecking programs and the restriction of body checking to elite levels of boys' youth ice hockey, starting no earlier than 15 years of age.

  2. Integration of the functional movement screen into the National Hockey League Combine.

    Rowan, Chip P; Kuropkat, Christiane; Gumieniak, Robert J; Gledhill, Norman; Jamnik, Veronica K

    2015-05-01

    The sport of ice hockey requires coordination of complex skills involving musculoskeletal and physiological abilities while simultaneously exposing players to a high risk for injury. The Functional Movement Screen (FMS) was developed to assess fundamental movement patterns that underlie both sport performance and injury risk. The top 111 elite junior hockey players from around the world took part in the 2013 National Hockey League Entry Draft Combine (NHL Combine). The FMS was integrated into the comprehensive medical and physiological fitness evaluations at the request of strength and conditioning coaches with affiliations to NHL teams. The inclusion of the FMS aimed to help develop strategies that could maximize its utility among elite hockey players and to encourage or inform further research in this field. This study evaluated the outcomes of integrating the FMS into the NHL Combine and identified any links to other medical plus physical and physiological fitness assessment outcomes. These potential associations may provide valuable information to identify elements of future training programs that are individualized to athletes' specific needs. The results of the FMS (total score and number of asymmetries identified) were significantly correlated to various body composition measures, aerobic and anaerobic fitness, leg power, timing of recent workouts, and the presence of lingering injury at the time of the NHL Combine. Although statistically significant correlations were observed, the implications of the FMS assessment outcomes remain difficult to quantify until ongoing assessment of FMS patterns, tracking of injuries, and hockey performance are available.

  3. Factors Influencing the Underreporting of Concussion in Sports: A Qualitative Study of Minor Hockey Participants.

    Cusimano, Michael D; Topolovec-Vranic, Jane; Zhang, Stanley; Mullen, Sarah J; Wong, Mattew; Ilie, Gabriela

    2017-07-01

    The present study is to identify factors contributing to underreporting of concussion in adolescent athletes. Qualitative interviews. Participants were interviewed in an office environment. Interviews were conducted with 31 minor hockey players, 10 parents, 6 coaches, 4 trainers, 2 managers, and one game official. Players were 13 to 15 year old. With selective sampling, an inductive approach of analyzing the interviews was undertaken and themes were identified and analyzed. Underreporting is a complex phenomenon. A number of risk factors related to hockey culture, players, reference others, and rules of play were assessed. Reasons not reporting concussion is accepted in minor hockey. Aspects of hockey culture such as an overemphasis on winning games and upheld misperceptions about the risks associated with concussion were identified as relevant to the underreporting of concussions. Various factors relevant to the underreporting of concussions include player's motivation to win, group membership dynamics such as a player's role as the team's "enforcer," coaches' own motivation to win to further their own opportunities in the sport, and parents' personal financial interest or alternative agenda in terms of time commitments and their child's future career prospects. Our findings indicate that underreporting of concussion among those players interviewed appears to be prevalent and associated with misconceptions about injury risk, and a culture that both reinforces and encourages underreporting with tacit or overt complicity of parents and coaches. Our findings support the need to alter the culture of violence and tough play in hockey by education, rule changes, economic measures, and changes in governance of the sport. Interviewing more stakeholders and policy makers would shed light on such potential interventions.

  4. Checking in: An Analysis of the (Lack of) Body Checking in Women's Ice Hockey

    Weaving, Charlene; Roberts, Samuel

    2012-01-01

    Despite the growing popularity of women's ice hockey in North America, players continue to face limitations because of the prohibition of body checking. In this paper, we argue from a liberal feminist philosophical perspective that this prohibition reinforces existing traditional stereotypes of female athletes. Because the women's game does not…

  5. Impact of visors on eye and orbital injuries in the National Hockey League.

    Micieli, Jonathan A; Zurakowski, David; Ahmed, Iqbal Ike K

    2014-06-01

    Eye and orbital injuries are a significant risk to professional hockey league players and have resulted in career-ending injuries. The goal of this study was to determine the incidence, value lost, mechanism, and effect of visors on eye and orbital injuries over the last 10 National Hockey League (NHL) seasons: 2002-2003 to 2012-2013. Retrospective case-control study. Participants were 8741 NHL players who had played at least 1 game during the last 10 seasons. Using The Sports Network (TSN), ProSportsTransactions, and the Sporting News Hockey Register, NHL players were searched to identify eye and orbital injuries. The mechanism of injury was obtained from media reports and direct observation from online videos. The number of players wearing visors each year was obtained from The Hockey News annual visor survey. A total of 149 eye or orbital injuries over the last 10 seasons resulted in an overall incidence of 2.48 per 10 000 athlete exposures. A total of 1120 missed games led to a lost financial value of more than $33 million. Visor use among players grew from 32% in 2002-2003 to 73% in 2012-2013, and there was a significantly increased risk for having an eye or orbital injury when a visor was not worn (OR 4.23, 95% CI 2.84-6.30). Most injuries were a result of being hit by a deflected or direct puck (37%) followed by being struck by a high stick (28%). Players who did not wear a visor were found to be involved in more fights, hits, and penalty minutes (p < 0.001). Eye and orbital injuries are mostly accidental in nature and represent a significant risk and cost to the NHL and its players. Eye and orbital injuries are significantly more likely in players who do not wear visors. Copyright © 2014 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved.

  6. Does fair play reduce concussions? A prospective, comparative analysis of competitive youth hockey tournaments.

    Smith, Aynsley M; Gaz, Daniel V; Larson, Dirk; Jorgensen, Janelle K; Eickhoff, Chad; Krause, David A; Fenske, Brooke M; Aney, Katie; Hansen, Ashley A; Nanos, Stephanie M; Stuart, Michael J

    2016-01-01

    To determine if Boys Bantam and Peewee and Girls U14 sustain fewer concussions, head hits, 'other injuries' and penalties in hockey tournaments governed by intensified fair play (IFP) than non-intensified fair play (NIFP). A prospective comparison of IFP, a behaviour modification programme that promotes sportsmanship, versus control (non-intensified, NIFP) effects on numbers of diagnosed concussions, head hits without diagnosed concussion (HHWDC), 'other injuries', number of penalties and fair play points (FPPs). 1514 players, ages 11-14 years, in 6 IFP (N=950) and 5 NIFP (N=564) tournaments were studied. Two diagnosed concussions, four HHWDC, and six 'other injuries' occurred in IFP tournaments compared to one concussion, eight HHWDC and five 'other injuries' in NIFP. There were significantly fewer HHWDC in IFP than NIFP (p=0.018). However, diagnosed concussions, 'other injuries', penalties and FPPs did not differ significantly between conditions. In IFP, a minority of teams forfeited the majority of FPPs. Most diagnosed concussions, HHWDC, and other injuries occurred to Bantam B players and usually in penalised teams that forfeited their FPPs. In response to significant differences in HHWDC between IFP and NIFP tournaments, the following considerations are encouraged: mandatory implementation of fair play in regular season and tournaments, empowering tournament directors to not accept heavily penalised teams, and introducing 'no body checking' in Bantam.

  7. Physiological correlates of skating performance in women's and men's ice hockey.

    Gilenstam, Kajsa M; Thorsen, Kim; Henriksson-Larsén, Karin B

    2011-08-01

    The purpose of the current investigation was to identify relationships between physiological off-ice tests and on-ice performance in female and male ice hockey players on a comparable competitive level. Eleven women, 24 ± 3.0 years, and 10 male ice hockey players, 23 ± 2.4 years, were tested for background variables: height, body weight (BW), ice hockey history, and lean body mass (LBM) and peak torque (PT) of the thigh muscles, VO2peak and aerobic performance (Onset of Blood Lactate Accumulation [OBLA], respiratory exchange ratio [RER1]) during an incremental bicycle ergometer test. Four different on-ice tests were used to measure ice skating performance. For women, skating time was positively correlated (p skating time was positively correlated to VO2peak (L O2·min(-1)) in the Acceleration test. The male group had significantly higher physiological test values in all variables (absolute and relative to BW) but not in relation to LBM. Selected off-ice tests predict skating performance for women but not for men. The group of women was significantly smaller and had a lower physiological performance than the group of men and were slower in the on-ice performance tests. However, gender differences in off-ice variables were reduced or disappeared when values were related to LBM, indicating a similar capacity of producing strength and aerobic power in female and male hockey players. Skating performance in female hockey players may be improved by increasing thigh muscle strength, oxygen uptake, and relative muscle mass.

  8. Differences in Lower Body Kinematics during Forward Treadmill Skating Between Two Different Hockey Skate Designs

    Mike R. Hellyer

    2016-01-01

    Full Text Available Purpose: The purpose of this study was to investigate the differences in ankle flexibility and skating technique between a traditional hockey skate boot and a hockey skate boot with a flexible rear tendon guard. Skating technique was further investigated at different speeds to give insight on how skating technique alters as skating speed is increased. Methods: Eight elite hockey players were selected for the present study, which was conducted while skating on an Endless Ice Skating Treadmill.  Variables were recorded using a three-camera setup and measured from video records at five selected treadmill speeds using the Dartfish Team Pro v6 software.  Kinematic variables were then compared between the two skate designs with a doubly multivariate repeated measures design.  Statistical significance was set at p<0.05.  Results: Post hoc univariate tests comparing skate designs displayed significant increases in plantar flexion, plantar flexion angular velocity, hip extension, hip extension angular velocity, stride length, and stride velocity while participants were wearing the skates that had a flexible rear tendon guard.  Significant increases were also displayed in plantar flexion, plantar flexion angular velocity, knee extension, knee extension angular velocity, hip extension, hip extension angular velocity, hip abduction range of motion, hip abduction angular velocity, stride width, stride length, and stride velocity as the treadmill speed increased. There was also a significant decrease in the time the skate was in contact with the treadmill as treadmill speed increased. Conclusion: The results suggested that while skating forward, hockey players could improve their hockey skating technique by using hockey skates that have a flexible rear tendon guard.  This flexible tendon guard improved skating technique by increasing the time of force application to the ice by increasing the range of ankle plantar flexion during propulsion of the

  9. Conservative management of an elite ice hockey goaltender with femoroacetabular impingement (FAI): a case report

    MacIntyre, Kyle; Gomes, Brendan; MacKenzie, Steven; D’Angelo, Kevin

    2015-01-01

    Objective: To detail the presentation of an elite male ice hockey goaltender with cam-type femoroacetabular impingement (FAI) and acetabular labral tears. This case will outline the prevalence, clinical presentation, imaging criteria, pathomechanics, and management of FAI, with specific emphasis on the ice hockey goaltender. Clinical Features: A 22-year old retired ice hockey goaltender presented to a chiropractor after being diagnosed by an orthopaedic surgeon with MRI confirmed left longitudinal and chondral flap acetabular labral tears and cam-type femoroacetabular impingement (FAI). As the patient was not a candidate for surgical intervention, a multimodal conservative treatment approach including manual therapy, electroacupuncture and rehabilitation exercises were implemented. Summary: FAI is prevalent in ice hockey players, particularly with goaltenders. Both skating and position-dependent hip joint mechanics involved in ice hockey may exacerbate or contribute to acquired and congenital forms of symptomatic FAI. As such, practitioners managing this population must address sport-specific demands in manual therapy, rehabilitation and physical training, to improve functional outcomes and prevent future injury. PMID:26816416

  10. Mechanisms of injury for concussions in university football, ice hockey, and soccer.

    Delaney, J Scott; Al-Kashmiri, Ammar; Correa, José A

    2014-05-01

    To examine the mechanisms of injury for concussions in university football, ice hockey, and soccer. Prospective cohort design. McGill University Sport Medicine Clinic. Male and female athletes participating in varsity football, ice hockey, and soccer. Athletes were followed prospectively over a 10-year period to determine the mechanisms of injury for concussions and whether contact with certain areas of the body or individual variables predisposed to longer recovery from concussions. For soccer, data were collected on whether concussions occurred while attempting to head the ball. There were 226 concussions in 170 athletes over the study period. The side/temporal area of the head or helmet was the most common area to be struck resulting in concussion in all 3 sports. Contact from another player's head or helmet was the most probable mechanism in football and soccer. In hockey, concussion impacts were more likely to occur from contact with another body part or object rather than another head/helmet. Differences in mechanisms of injuries were found between males and females in soccer and ice hockey. Athletes with multiple concussions took longer to return to play with each subsequent concussion. Half of the concussions in soccer were related to attempting to head the soccer ball. The side of the head or helmet was the most common area to be struck resulting in concussion in all 3 sports. In ice hockey and soccer, there are differences in the mechanisms of injury for males and females within the same sport.

  11. Sports chiropractic management at the World Ice Hockey Championships

    Vitiello Andrew L

    2010-12-01

    Full Text Available Abstract Background Ice hockey is an international sport. Injuries occur in a full body fashion, to a number of tissues, commonly through body contact. There is a lack of literature documenting the scope of sports chiropractic practice. Thus, it was the aim to document the type, scope and severity of conditions presenting to, and the treatment provided by, the New Zealand team chiropractor acting as a primary health provider for the duration of the 2007 World Ice Hockey Championships. Methods All conditions presenting were recorded. Diagnosis was recorded along with clinical parameters of injury: injury type, severity, mechanism and whether referral or advanced imaging was required. All treatment provided was continuously recorded, including information on the number of treatments required and the reason, duration, type and location of treatment. Results Players presented for diagnosis of injury 50 times. Muscle (34%, joint (24% and tendon injuries (18% were most common. Players presented with a new injury 76% of the time. Most injuries had been present for less than one week (84%, with 53% occurring through a contact mechanism. Injuries were common at training and match locations. Only two injuries required the player to stop playing or training, both of which were referred for advanced imaging. During the study, 134 treatment consultations were rendered to 45 player injuries. Eighty per-cent of injuries were managed with four or less treatments. Three quarters of treatment was provided at training locations with treatment duration predominantly being between 11-15 minutes (71% and 16-20 minutes (27%. Most treatment delivered was passive in nature (71% although combination active and passive care was provided (27%. Treatment typically involved joint (81% and soft tissue based therapies (81% and was delivered in a full body manner. Conclusions This study documented the injury profile of ice hockey at an international level of competition. It

  12. Effects of badminton and ice hockey on bone mass in young males: a 12-year follow-up.

    Tervo, Taru; Nordström, Peter; Nordström, Anna

    2010-09-01

    The purpose of the present study was to investigate the influence of different types of weight bearing physical activity on bone mineral density (BMD, g/cm(2)) and evaluate any residual benefits after the active sports career. Beginning at 17 years of age, BMD was measured 5 times, during 12 years, in 19 badminton players, 48 ice hockey players, and 25 controls. During the active career, badminton players gained significantly more BMD compared to ice hockey players at all sites: in their femoral neck (mean difference (Delta) 0.06 g/cm(2), p=0.04), humerus (Delta 0.06 g/cm(2), p=0.01), lumbar spine (Delta 0.08 g/cm(2), p=0.01), and their legs (Delta 0.05 g/cm(2), p=0.003), after adjusting for age at baseline, changes in weight, height, and active years. BMD gains in badminton players were higher also compared to in controls at all sites (Delta 0.06-0.17 g/cm(2), pbadminton players and 37 ice hockey players stopped their active career a mean of 6 years before the final follow-up. Both these groups lost significantly more BMD at the femoral neck and lumbar spine compared to the control group (Delta 0.05-0.12 g/cm(2), pbadminton players had significantly higher BMD of the femoral neck, humerus, lumbar spine, and legs (Delta 0.08-0.20 g/cm(2), pbadminton is a more osteogenic sport compared to ice hockey. The BMD benefits from previous training were partially sustained with reduced activity. Copyright 2010 Elsevier Inc. All rights reserved.

  13. THE COMPETITIVE DEMANDS OF ELITE MALE RINK HOCKEY

    Aladino Fernández

    2013-06-01

    Full Text Available The aim of this study was to simulate the activity pattern of rink hockey by designing a specific skate test (ST to study the energy expenditure and metabolic responses to this intermittent high-intensity exercise and extrapolate the results from the test to competition. Six rink hockey players performed, in three phases, the 20-metre multi-stage shuttle roller skate test, a tournament match and the ST. Heart rate was monitored in all three phases. Blood lactate, oxygen consumption, ventilation and respiratory exchange ratio were also recorded during the ST. Peak HR was 190.7±7.2 beats · min-1. There were no differences in peak HR between the three tests. Mean HR was similar between the ST and the match (86% and 87% of HRmax, respectively. Peak and mean ventilation averaged 111.0±8.8 L · min-1 and 70.3±14.0 L · min-1 (60% of VEmax, respectively. VO2max was 56.3±8.4 mL · kg-1 · min-1, and mean oxygen consumption was 40.9±7.9 mL · kg-1 · min-1 (70% of VO2max. Maximum blood lactate concentration was 7.2±1.3 mmol · L-1. ST yielded an energy expenditure of 899.1±232.9 kJ, and energy power was 59.9±15.5 kJ · min-1. These findings suggest that the ST is suitable for estimating the physiological demands of competitive rink hockey, which places a heavy demand on the aerobic and anaerobic systems, and requires high energy consumption.

  14. Optimization of the Hockey Fans in Training (Hockey FIT) weight loss and healthy lifestyle program for male hockey fans.

    Blunt, Wendy; Gill, Dawn P; Sibbald, Shannon L; Riggin, Brendan; Pulford, Roseanne W; Scott, Ryan; Danylchuk, Karen; Gray, Cindy M; Wyke, Sally; Bunn, Christopher; Petrella, Robert J

    2017-11-28

    The health outcomes of men continue to be poorer than women globally. Challenges in addressing this problem include difficulties engaging men in weight loss programs as they tend to view these programs as contrary to the masculine narrative of independence and self-reliance. Researchers have been turning towards sports fans to engage men in health promotion programs as sports fans are typically male, and tend to have poor health habits. Developed from the highly successful gender-sensitized Football Fans in Training program, Hockey Fans in Training (Hockey FIT) recruited 80 male hockey fans of the London Knights and Sarnia Sting who were overweight or obese into a weekly, 90-minute classroom education and group exercise program held over 12 weeks; a 40-week minimally-supported phase followed. A process evaluation of the Hockey FIT program was completed alongside a pragmatic randomized controlled trial and outcome evaluation in order to fully explore the acceptability of the Hockey FIT program from the perspectives of coaches delivering and participants engaged in the program. Data sources included attendance records, participant focus groups, coach interviews, assessment of fidelity (program observations and post-session coach reflections), and 12-month participant interviews. Coaches enjoyed delivering the program and found it simple to deliver. Men valued being among others of similar body shape and similar weight loss goals, and found the knowledge they gained through the program helped them to make and maintain health behaviour changes. Suggested improvements include having more hockey-related information and activities, greater flexibility with timing of program delivery, and greater promotion of technology support tools. We confirmed Hockey FIT was an acceptable "gender-sensitized" health promotion program for male hockey fans who were overweight or obese. Minor changes were required for optimization, which will be evaluated in a future definitive trial

  15. A systematic video analysis of National Hockey League (NHL) concussions, part I: who, when, where and what?

    Hutchison, Michael G; Comper, Paul; Meeuwisse, Willem H; Echemendia, Ruben J

    2015-04-01

    Although there is a growing understanding of the consequences of concussions in hockey, very little is known about the precipitating factors associated with this type of injury. To describe player characteristics and situational factors associated with concussions in the National Hockey League (NHL). Case series of medically diagnosed concussions for regular season games over a 3.5-year period during the 2006-2010 seasons using an inclusive cohort of professional hockey players. Digital video records were coded and analysed using the Heads Up Checklist. Of 197 medically diagnosed concussions, 88% involved contact with an opponent. Forwards accounted for more concussions than expected compared with on-ice proportional representation (95% CI 60 to 73; p=0.04). Significantly more concussions occurred in the first period (47%) compared with the second and third periods (p=0.047), with the majority of concussions occurring in the defensive zone (45%). Approximately 47% of the concussions occurred in open ice, 53% occurred in the perimeter. Finally, 37% of the concussions involved injured players' heads contacting the boards or glass. This study describes several specific factors associated with concussions in the NHL, including period of the game, player position, body size, and specific locations on the ice and particular situations based on a player's position. 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.

  16. The Protective Effect of Kevlar ® Socks Against Hockey Skate Blade Injuries: A Biomechanical Study

    Nauth, Aaron; Aziz, Mina; Tsuji, Matthew; Whelan, Daniel B.; Theodoropoulos, John S.; Zdero, Rad

    2014-01-01

    Objectives: Several recent high profile injuries to elite players in the National Hockey League (NHL) secondary to skate blade lacerations have generated significant interest in these injuries and possible methods to protect against them. These injuries are typically due to direct contact of the skate blade of another player with posterior aspect of the calf resulting in a range of potential injuries to tendons or neurovascular structures. The Achilles tendon is most commonly involved. Kevlar® reinforced socks have recently become available for hockey players to wear and are cited as providing possible protection against such injuries. However, there has been no investigation of the possible protective effects of Kevlar® reinforced socks against skate blade injuries, and it is currently unknown what protective effects, if any, that these socks provide against these injuries. The proposed study sought to address this by conducting a biomechanical investigation of the protective effects of Kevlar® reinforced socks against Achilles tendon injuries in a simulated model of skate blade injury using human cadaver limbs. This novel investigation is the first to address the possible benefits to hockey players of wearing Kevlar® reinforced socks. Methods: Seven matched pairs of human cadaver lower limbs were fitted with a Kevlar ® reinforced sock comprised of 60% Kevlar®/20% Coolmax® polyester/18 % Nylon/12% Spandex (Bauer Elite Performance Skate Sock) on one limb and a standard synthetic sock comprised of 51% polyester/47% nylon/2% spandex (Bauer Premium Performance Skate Sock) on the contralateral limb as a control. Each limb was then mounted on a Materials Testing System (MTS) with the ankle dorsiflexed to 90° and the knee held in full extension using a custom designed jig. Specimens were then impacted with a hockey skate blade directed at the posterior calf, 12 cm above the heel, at an angle of 45° and a speed of 31m/s, to a penetration depth of 4.3 cm, to

  17. Evaluation of cardiovascular demands of game play and practice in women's ice hockey.

    Spiering, Barry A; Wilson, Meredith H; Judelson, Daniel A; Rundell, Kenneth W

    2003-05-01

    Preparation for the physical demands of competition often involves game simulation during practice. This paradigm is thought to promote physiological adaptations that enhance maximal performance. However, a mismatch between practice intensity and actual competition intensity may not provide adequate training to achieve optimal game-play fitness. The purpose of this study was to evaluate the effectiveness of practice in meeting the cardiovascular demands of a women's ice hockey game. Heart rate (HR) data from 11 U.S. National Women's Ice Hockey team members were collected (5-second intervals) during a game and a typical practice session. Data was normalized to individual HRmax determined during Vo(2)max testing. Working time was defined as a game shift or practice-working interval. Mean working HR was greater during the game than the practice, 90 +/- 2% and 76 +/- 3% of HRmax, respectively (p game or practice) >90% HRmax was also longer during the game than the practice, 10.5 +/- 4.1% and 5.6 +/- 3.5% (p 80% HRmax, and mean resting HR were not different between game and practice (68 +/- 7% vs. 69 +/- 5%, 23.2 +/- 5.3% vs. 26.1 +/- 9.2%, and 59 +/- 8% vs. 56 +/- 5%, respectively). Elite women hockey players experience significantly greater cardiovascular load during game play than during practice. This mismatch in cardiovascular demand may prevent players from achieving "game shape," thus affecting competition play.

  18. A 26 year physiological description of a National Hockey League team.

    Quinney, H A; Dewart, Randy; Game, Alex; Snydmiller, Gary; Warburton, Darren; Bell, Gordon

    2008-08-01

    The primary purpose of this investigation was to examine the physiological profile of a National Hockey League (NHL) team over a period of 26 years. All measurements were made at a similar time of year (pre-season) in 703 male (mean age +/- SD = 24 +/- 4 y) hockey players. The data were analyzed across years, between positions (defensemen, forwards, and goaltenders), and between what were deemed successful and non-successful years using a combination of points acquired during the season and play-off success. Most anthropometric (height, mass, and BMI) and physiological parameters (absolute and relative VO2 peak, relative peak 5 s power output, abdominal endurance, and combined grip strength) showed a gradual increase over the 26 year period. Defensemen were taller and heavier, had higher absolute VO2 peak, and had greater combined grip strength than forwards and goaltenders. Forwards were younger and had higher values for relative VO2 peak. Goaltenders were shorter, had less body mass, a higher sum of skinfolds, lower VO2 peak, and better flexibility. The overall pre-season fitness profile was not related to team success. In conclusion, this study revealed that the fitness profile for a professional NHL ice-hockey team exhibited increases in player size and anaerobic and aerobic fitness parameters over a 26 year period that differed by position. However, this evolution of physiological profile did not necessarily translate into team success in this particular NHL franchise.

  19. Video Gaming Promotes Concussion Knowledge Acquisition in Youth Hockey Players

    Goodman, David; Bradley, Nori L.; Paras, Bradley, Williamson, Ian J.; Bizzochi, James

    2006-01-01

    While the positive uses for video games in an educational setting have also been established, the educational aim is usually made explicit. The goal of this research was to develop a video game wherein the educational aspect was implicitly embedded in the video game, such that the gameing activity remained interesting and relevant. Following a…

  20. Locomotor, Heart-Rate, and Metabolic Power Characteristics of Youth Women's Field Hockey: Female Athletes in Motion (FAiM) Study

    Vescovi, Jason D.

    2016-01-01

    Purpose: The purpose of this study was to quantify the locomotor, heart-rate, and metabolic power characteristics of high-level youth female field hockey matches. Method: Players from the U21 and U17 Canadian women's national teams were monitored during a 4-match test series using Global Positioning System technology. Position (forward,…

  1. Analysis of High-Intensity Skating in Top-Class Ice Hockey Match-Play in Relation to Training Status and Muscle Damage.

    Lignell, Erik; Fransson, Dan; Krustrup, Peter; Mohr, Magni

    2018-05-01

    Lignell, E, Fransson, D, Krustrup, P, and Mohr, M. Analysis of high-intensity skating in top-class ice hockey match-play in relation to training status and muscle damage. J Strength Cond Res 32(5): 1303-1310, 2018-We examined high-intensity activities in a top-class ice-hockey game and the effect of training status. Male ice-hockey players (n = 36) from the National Hockey League participated. Match analysis was performed during a game and physical capacity was assessed by a submaximal Yo-Yo Intermittent Recovery Ice-hockey test, level 1 (YYIR1-IHSUB). Venous blood samples were collected 24-hour post-game to determine markers of muscle damage. Players performed 119 ± 8 and 31 ± 3 m·min of high intensity and sprint skating, respectively, during a game. Total distance covered was 4,606 ± 219 m (2,260-6,749 m), of which high-intensity distance was 2042 ± 97 m (757-3,026 m). Sprint-skating speed was 5-8% higher (p ≤ 0.05) in periods 1 and 2 vs. period 3 and overtime. Defensemen (D) covered 29% more (p ≤ 0.05) skating in total than forwards (F) and were on the ice 47% longer. However, F performed 54% more (p ≤ 0.05) high-intensity skating per minute than defensemen. Plasma creatine kinase (CK) was 338 ± 45 (78-757) U·L 24-hour post-game. Heart rate loading during YYIR1-IHSUB correlated inversely (p ≤ 0.05) to the frequency of high-intensity skating bouts (r = -0.55) and V[Combining Dot Above]O2max (r = -0.85) and positively to post-game CK (r = 0.49; p ≤ 0.05). In conclusion, ice hockey is a multiple-sprint sport that provokes fatigue in the latter half of a game. Forwards perform more intense skating than defensemen. Moreover, high-intensity game activities during top-class ice hockey are correlated with cardiovascular loading during a submaximal skating test. Taken together, training of elite ice-hockey players should improve the ability for repeated high-intensity skating, and testing should include the YYIR1-IHSUB test as an indicator for ice-hockey

  2. Developmental contexts and sporting success: birth date and birthplace effects in national hockey league draftees 2000-2005.

    Baker, Joseph; Logan, A Jane

    2007-08-01

    To examine relative age and birth place effects in hockey players drafted to play in the National Hockey League (NHL) between 2000 and 2005 and determine whether these factors influenced when players were chosen in the draft. 1013 North American draftees were evaluated from the official NHL website, which provided birthplace, date of birth and selection order in the draft. Population size was collected from Canadian and American census information. Athletes were divided into four quartiles on the basis of selection date to define age cohorts in hockey. Data between the Canadian and American players were also compared to see if the optimal city sizes differed between the two nations. Relative age and birthplace effects were found, although the optimal city size found was dissimilar to that found in previous studies. Further, there were inconsistencies between the Canadian and American data. Contextual factors such as relative age and size of birthplace have a significant effect on likelihood of being selected in the NHL draft.

  3. Working in Danish ice hockey

    Larsen, Carsten H.

    2018-01-01

    . In terms of identifying psychological areas of development, I used information from multiple sources, including the coaches, staff, players, and also observations of practice and competition. Three different but connected areas were targeted with the junior national team. First, creating an understanding...... and acceptance of roles within the team. Second, developing effective team communication under pressure. Third, learning the ability to register thoughts, release thoughts, and refocus under pressure. I then make conclusions by reflecting upon the effectiveness of services for the junior national team...

  4. An on-ice measurement approach to analyse the biomechanics of ice hockey skating.

    Erica Buckeridge

    Full Text Available Skating is a fundamental movement in ice hockey; however little research has been conducted within the field of hockey skating biomechanics due to the difficulties of on-ice data collection. In this study a novel on-ice measurement approach was tested for reliability, and subsequently implemented to investigate the forward skating technique, as well as technique differences across skill levels. Nine high caliber (High and nine low caliber (Low hockey players performed 30 m forward skating trials. A 3D accelerometer was mounted to the right skate for the purpose of stride detection, with the 2nd and 6th strides defined as acceleration and steady-state, respectively. The activity of five lower extremity muscles was recorded using surface electromyography. Biaxial electro-goniometers were used to quantify hip and knee angles, and in-skate plantar force was measured using instrumented insoles. Reliability was assessed with the coefficient of multiple correlation, which demonstrated moderate (r>0.65 to excellent (r>0.95 scores across selected measured variables. Greater plantar-flexor muscle activity and hip extension were evident during acceleration strides, while steady state strides exhibited greater knee extensor activity and hip abduction range of motion (p<0.05. High caliber exhibited greater hip range of motion and forefoot force application (p<0.05. The successful implementation of this on-ice mobile measurement approach offers potential for athlete monitoring, biofeedback and training advice.

  5. An on-ice measurement approach to analyse the biomechanics of ice hockey skating.

    Buckeridge, Erica; LeVangie, Marc C; Stetter, Bernd; Nigg, Sandro R; Nigg, Benno M

    2015-01-01

    Skating is a fundamental movement in ice hockey; however little research has been conducted within the field of hockey skating biomechanics due to the difficulties of on-ice data collection. In this study a novel on-ice measurement approach was tested for reliability, and subsequently implemented to investigate the forward skating technique, as well as technique differences across skill levels. Nine high caliber (High) and nine low caliber (Low) hockey players performed 30 m forward skating trials. A 3D accelerometer was mounted to the right skate for the purpose of stride detection, with the 2nd and 6th strides defined as acceleration and steady-state, respectively. The activity of five lower extremity muscles was recorded using surface electromyography. Biaxial electro-goniometers were used to quantify hip and knee angles, and in-skate plantar force was measured using instrumented insoles. Reliability was assessed with the coefficient of multiple correlation, which demonstrated moderate (r>0.65) to excellent (r>0.95) scores across selected measured variables. Greater plantar-flexor muscle activity and hip extension were evident during acceleration strides, while steady state strides exhibited greater knee extensor activity and hip abduction range of motion (p<0.05). High caliber exhibited greater hip range of motion and forefoot force application (p<0.05). The successful implementation of this on-ice mobile measurement approach offers potential for athlete monitoring, biofeedback and training advice.

  6. MASCULINITY AND SPORT REVISTED: A REVIEW OF LITERATURE ON HEGEMONIC MASCULINITY AND MEN'S ICE HOCKEY IN CANADA

    Cheryl A. MacDonald

    2014-04-01

    Full Text Available Ice hockey is particularly significant in Canada as it acts as a primary site of socialization for boys and men. This form of socialization raises questions about masculinity on the public agenda in terms of the problematic nature of hypermasculinity in sport, stereotypical images of athletes, and questions of social responsibility as both men and athletes. These issues are presently relevant as Canada (and perhaps all of North America finds itself in an era characterized by accounts in mainstream media of competitive athletes’ cavalier lifestyles, hazing, violence, homophobia, drug addictions, and suicides. This review of literature uses secondary research to problematize masculinity in the ice hockey context by presenting the overarching claim that male hockey players are hegemonically masculine individuals. The piece begins by defining Australian sociologist R.W. Connell’s (1987 concept of hegemonic masculinity and situating it in the contemporary academic context. Next, it offers an overview of relevant literature on masculinity and sport along with a concise examination of scholarly work on the relationship between hegemonic masculinity and ice hockey in Canada. It concludes by summarising calls for further research in the literature and by suggesting approaches to future studies in the field.

  7. Update and Overview of Spinal Injuries in Canadian Ice Hockey, 1943 to 2011: The Continuing Need for Injury Prevention and Education.

    Tator, Charles H; Provvidenza, Christine; Cassidy, J David

    2016-05-01

    To identify spinal injuries in Canadian ice hockey from 2006 to 2011 and to discuss data from 1943 to 2011 and impact of injury prevention programs. Data about spinal injuries with and without spinal cord injury in ice hockey have been collected by ThinkFirst's (now Parachute Canada) Canadian Ice Hockey Spinal Injuries Registry since 1981 through questionnaires from practitioners, ice hockey organizations, and media. All Canadian provinces and territories. All registered Canadian ice hockey players. Age, gender, level of play, location, mechanism of injury. Incidence, incidence rate, prevalence, and nature (morbidity) of the injuries. Between 2006 and 2011, 44 cases occurred, 4 (9.1%) of which were severe. The incidence in the recent years continues to be lower than the peak years. From 1943 to 2011, 355 cases have been documented, primarily males (97.7%) and cervical spine injuries (78.9%), resulting from impact with the boards (64.2%). Check or push from behind (36.0%) was still the most common cause of injury, although slightly lower during 2006 to 2011. From 1943 to 2011, Prince Edward Island, New Brunswick, and British Columbia/Yukon had the highest injury rates. Ontario and Quebec continued to show markedly different injury rates, with Ontario more than twice that of Quebec. Current data for 2006 to 2011 indicate that spinal injuries in ice hockey continue to occur, although still at lower rates than the peak years 1982 to 1995. It is imperative to continue educating players and team officials about spinal injury prevention and to reinforce the rules against checking or pushing from behind to reduce the incidence of these serious injuries.

  8. Model trees for identifying exceptional players in the NHL and NBA draft

    Liu, Yejia

    2018-01-01

    Drafting players is crucial for a team’s success. We describe a data-driven interpretable approach for assessing prospects in the National Hockey League and National Basketball Association. Previous approaches have built a predictive model based on player features, or derived performance predictions from comparable players. Our work develops model tree learning, which incorporates strengths of both model-based and cohort-based approaches. A model tree partitions the feature space according to...

  9. THE ROLE OF AEROBIC CAPACITY IN HIGH-INTENSITY INTERMITTENT EFFORTS IN ICE-HOCKEY

    A. Stanula

    2014-08-01

    Full Text Available The primary objective of this study was to determine a relationship between aerobic capacity ( ·VO2max and fatigue from high-intensity skating in elite male hockey players. The subjects were twenty-four male members of the senior national ice hockey team of Poland who played the position of forward or defence. Each subject completed an on-ice Repeated-Skate Sprint test (RSS consisting of 6 timed 89-m sprints, with 30 s of rest between subsequent efforts, and an incremental test on a cycle ergometer in the laboratory, the aim of which was to establish their maximal oxygen uptake ( ·VO2max. The analysis of variance showed that each next repetition in the 6x89 m test was significantly longer than the previous one (F5,138=53.33, p<0.001. An analysis of the fatigue index (FI calculated from the times recorded for subsequent repetitions showed that the value of the FI increased with subsequent repetitions, reaching its maximum between repetitions 5 and 6 (3.10±1.16%. The total FI was 13.77±1.74%. The coefficient of correlation between ·VO2max and the total FI for 6 sprints on the distance of 89 m (r =–0.584 was significant (p=0.003. The variance in the index of players’ fatigue in the 6x89 m test accounted for 34% of the variance in ·VO2max. The 6x89 m test proposed in this study offers a high test-retest correlation coefficient (r=0.78. Even though the test is criticized for being too exhaustive and thereby for producing highly variable results it still seems that it was well selected for repeated sprint ability testing in hockey players.

  10. Upper body strength and power are associated with shot speed in men's ice hockey

    Juraj Bežák

    2017-06-01

    Full Text Available Background: Recent studies that addressed shot speed in ice hockey have focused on the relationship between shot speed and variables such as a player's skills or hockey stick construction and its properties. There has been a lack of evidence that considers the relationship between shot speed and player strength, particularly in players at the same skill level. Objective: The aim of this study was to identify the relationship between maximal puck velocity of two shot types (the wrist shot and the slap shot and players' upper body strength and power. Methods: Twenty male professional and semi-professional ice hockey players (mean age 23.3 ± 2.4 years participated in this study. The puck velocity was measured in five trials of the wrist shot and five trials of the slap shot performed by every subject. All of the shots were performed on ice in a stationary position 11.6 meters in front of an electronic device that measures the speed of the puck. The selected strength and power variables were: muscle power in concentric contraction in the countermovement bench press with 40 kg and 50 kg measured with the FiTRODyne Premium device; bench press one-repetition maximum; and grip strength measured by digital hand dynamometer. Results: The correlations between strength/power variables and the puck velocity in the wrist shot and the slap shot ranged between .29-.72 and .16-.62, respectively. Puck velocities produced by wrist shots showed significant correlations with bench press muscle power with 40 kg (p = .004 and 50 kg (p < .001; and one-repetition maximum in bench press (p = .004. The slap shot puck velocity was significantly associated with bench press muscle power with 40 kg (p = .014 and 50 kg (p = .004. Conclusions: This study provides evidence that there are significant associations between shot speed and upper body strength and power.

  11. Ice Hockey Lung – A Case of Mass Nitrogen Dioxide Poisoning in The Czech Republic

    Kristian Brat

    2013-01-01

    Full Text Available Nitrogen dioxide (NO2 is a toxic gas, a product of combustion in malfunctioning ice-resurfacing machines. NO2 poisoning is rare but potentially lethal. The authors report a case of mass NO2 poisoning involving 15 amateur ice hockey players in the Czech Republic. All players were treated in the Department of Respiratory Diseases at Brno University Hospital in November 2010 – three as inpatients because they developed pneumonitis. All patients were followed-up until November 2011. Complete recovery in all but one patient was achieved by December 2010. None of the 15 patients developed asthma-like disease or chronic cough. Corticosteroids appeared to be useful in treatment. Electric-powered ice-resurfacing machines are preferable in indoor ice skating arenas.

  12. Anterior Cruciate Ligament Injuries in the National Hockey League: Epidemiology and Performance Impact.

    Longstaffe, Robert; Leiter, Jeff; MacDonald, Peter

    2018-03-27

    To determine the incidence of anterior cruciate ligament (ACL) injuries in the National Hockey League (NHL) and to examine the effects of this injury on return-to-play status and performance. Case series; level of evidence, 4. This was a 2-phase study. Phase I used the NHL electronic injury surveillance system and Athlete Health Management System to collect data on ACL injuries and man games lost over 10 seasons (2006/2007-2015/2016). Data collected in phase I were received in deidentified form. Phase II examined the performance impact of an ACL injury. Players were identified through publically available sources, and performance-related statistics were analyzed. Data collected in phase II were not linked to data collected in phase I. A paired t test was used to determine any difference in the matching variables between controls and cases in the preinjury time period. A General linear model (mixed) was used to determine the performance impact. Phase I: 67 ACL injuries occurred over 10 seasons. The incidence for all players was 0.42/1000 player game hours (forward, 0.61; defenseman, 0.32, goalie, 0.08) and by game exposure was 0.2/1000 player game exposures (forward, 0.33; defenseman, 0.11; goalie, 0.07). Forwards had a greater incidence rate of ACL tears with both game hours and game exposures when compared with defensemen and goalies (P game (P game (0.001). Number of games and seasons played after an ACL injury did not differ compared with controls (P = 0.068, 0.122, respectively). Anterior cruciate ligament injuries occur infrequently, as it relates to other hockey injuries. Despite a high return to play, the performance after an ACL injury demonstrated a decrease in points and goals per game and per season.

  13. Effect of ice surface size on collision rates and head impacts at the World Junior Hockey Championships, 2002 to 2004.

    Wennberg, Richard

    2005-03-01

    To determine if collision rates and head impacts in elite junior hockey differed between games played on the small North American ice surface (85 ft wide), an intermediate-size Finnish ice surface (94 ft wide), and the large standard international ice surface (100 ft wide). Videotape analysis of all games involving Team Canada from the 2002 (large ice, Czech Republic), 2003 (small ice, Canada), and 2004 (intermediate ice, Finland) World Junior Championships. All collisions were counted and separated into various categories (volitional player/player bodychecks, into boards or open ice, plus accidental/incidental player/boards, player/ice, head/stick, head/puck). Further subdivisions included collisions involving the head directly or indirectly and notably severe head impacts. Small, intermediate, and large ice surface mean collisions/game, respectively, were 295, 258, 222, total collisions; 251, 220, 181, volitional bodychecks; 126, 115, 88, into boards; 125, 106, 93, open ice; 71, 52, 44, total head; 44, 36, 30, indirect head; 26, 16, 13, direct head; and 1.3, 0.5, 0.3, severe head (P < 0.05 for small-intermediate ice and intermediate-large ice differences in total collisions; P < 0.005 for small-large ice difference; P < 0.05 for small-intermediate ice differences in head impacts; P < 0.01 for small-large ice differences in total and severe head impacts). There is a significant inverse correlation between ice size and collision rates in elite hockey, including direct, indirect, and severe head impacts. These findings suggest that uniform usage of the larger international rinks could reduce the risk of injury, and specifically, concussions in elite hockey by decreasing the occurrence of collisions and head impacts.

  14. Hockey Fans in Training (Hockey FIT) pilot study protocol: a gender-sensitized weight loss and healthy lifestyle program for overweight and obese male hockey fans.

    Gill, Dawn P; Blunt, Wendy; De Cruz, Ashleigh; Riggin, Brendan; Hunt, Kate; Zou, Guangyong; Sibbald, Shannon; Danylchuk, Karen; Zwarenstein, Merrick; Gray, Cindy M; Wyke, Sally; Bunn, Christopher; Petrella, Robert J

    2016-10-19

    Effective approaches that engage men in weight loss and lifestyle change are important because of worldwide increases, including in Canada, in obesity and chronic diseases. Football Fans in Training (FFIT), developed in Scotland, successfully tackled these problems by engaging overweight/obese male football fans in sustained weight loss and positive health behaviours, through program deliveries at professional football stadia. Aims: 1) Adapt FFIT to hockey within the Canadian context and integrate with HealtheSteps™ (evidence-based lifestyle program) to develop Hockey Fans in Training (Hockey FIT); 2) Explore potential for Hockey FIT to help overweight/obese men lose weight and improve other outcomes by 12 weeks, and retain these improvements to 12 months; 3) Evaluate feasibility of recruiting and retaining overweight/obese men; 4) Evaluate acceptability of Hockey FIT; and 5) Conduct program optimization via a process evaluation. We conducted a two-arm pilot pragmatic randomized controlled trial (pRCT) whereby 80 overweight/obese male hockey fans (35-65 years; body-mass index ≥28 kg/m 2 ) were recruited through their connection to two junior A hockey teams (London and Sarnia, ON) and randomized to Intervention (Hockey FIT) or Comparator (Wait-List Control). Hockey FIT includes a 12-week Active Phase (classroom instruction and exercise sessions delivered weekly by trained coaches) and a 40-week Maintenance Phase. Data collected at baseline and 12 weeks (both groups), and 12 months (Intervention only), will inform evaluation of the potential of Hockey FIT to help men lose weight and improve other health outcomes. Feasibility and acceptability will be assessed using data from self-reports at screening and baseline, program fidelity (program observations and coach reflections), participant focus group discussions, coach interviews, as well as program questionnaires and interviews with participants. This information will be analyzed to inform program

  15. The identification of benefit needs of golf players in the U.S.: Implicationsand strategy considerations for sport management professionals

    CHUNG-MI LEE

    2006-01-01

    Full Text Available The golf industry has expanded over the past 50 years throughout the world, particularly in America. The number of golfers in the United States has increased seven-fold since 1950, as the game was transformed from an expensive diversion of the rich to a mass-market pastime. A number of recent studies have shown that demographic variables such as age, gender, occupation, income, and race are –in general– poor predictors of golfers’ consumer behaviour and, consequently, less than optimum bases for segmentation strategies. Because of those problems associated with demographic segmentation, benefit segmentation has become a favourite tool of marketers; to satisfy target consumers’ needs, benefit needs and product attributes are the most popular variables for segmenting the target market. The main strength of benefit segmentation lies in the causal relationship to perceived future behaviour. The purpose of this study was to identify the benefit needs of golfers who frequent public golf courses. Implications for public golf course owners or managers are then discussed with strategy considerations about golf marketing for a variety of benefit segments.

  16. Fuerza lumbar en jugadores de hockey hierba

    Til Pérez, Lluís; Barceló Peiró, Oriol; Pomés Díes, Teresa; Martínez Navas, Roberto; Galilea Ballarini, Pedro; Bellver Vives, Montserrat

    2007-01-01

    Introducción: El dolor lumbar tiene una alta prevalencia entre los deportistas, se ha relacionado con déficits en la fuerza extensora lumbar, y el hecho de padecerlo representa un obstáculo importante para la práctica de deportes de alta intensidad. Método: Se ha medido la fuerza lumbar en 2 grupos de practicantes de hockey hierba mediante máquina MedX® y un test de resistencia isométrico lumbar. Resultados: Entre ambos grupos los resultados han sido muy homogéneos....

  17. Creation of a strategic framework for global development of ice hockey

    Nieminen, Aku

    2016-01-01

    The International Ice Hockey Federation (IIHF) is the international governing body of ice hockey and inline hockey. Among many responsibilities and objectives, one of the main tasks of the IIHF is to develop ice hockey on a global scale. The IIHF has 74 Member National Associations which can benefit from the development programs of the IIHF. These development programs have the purpose of assisting and supporting the National Association in the domestic development of ice hockey in their count...

  18. Ground reaction forces produced by two different hockey skating arm swing techniques.

    Hayward-Ellis, Julie; Alexander, Marion J L; Glazebrook, Cheryl M; Leiter, Jeff

    2017-10-01

    The arm swing in hockey skating can have a positive effect on the forces produced by each skate, and the resulting velocity from each push off. The main purpose of this study was to measure the differences in ground reaction forces (GRFs) produced from an anteroposterior versus a mediolateral style hockey skating arm swing. Twenty-four elite-level female hockey players performed each technique while standing on a ground-mounted force platform, and all trials were filmed using two video cameras. Force data was assessed for peak scaled GRFs in the frontal and sagittal planes, and resultant GRF magnitude and direction. Upper limb kinematics were assessed from the video using Dartfish video analysis software, confirming that the subjects successfully performed two distinct arm swing techniques. The mediolateral arm swing used a mean of 18.38° of glenohumeral flexion/extension and 183.68° of glenohumeral abduction/adduction while the anteroposterior technique used 214.17° and 28.97° respectively. The results of this study confirmed that the mediolateral arm swing produced 37% greater frontal plane and 33% less sagittal plane GRFs than the anteroposterior arm swing. The magnitudes of the resultant GRFs were not significantly different between the two techniques; however, the mediolateral technique produced a resultant GRF with a significantly larger angle from the direction of travel (44.44°) as compared to the anteroposterior technique (31.60°). The results of this study suggest that the direction of GRFs produced by the mediolateral arm swing more closely mimic the direction of lower limb propulsion during the skating stride.

  19. Moral disengagement in the legitimation and realization of aggressive behavior in soccer and ice hockey.

    Traclet, Alan; Moret, Orlan; Ohl, Fabien; Clémence, Alain

    2015-03-01

    The aim of the present study was to verify that the level of tolerance for aggression is higher in a collective context than in an individual context (polarization effect), and to test the association between moral disengagement, team and self-attitudes toward aggression, and tolerance and realization of aggressive acts in Swiss male soccer and ice hockey. In individual or collective answering conditions, 104 soccer and 98 ice hockey players viewed videotaped aggressive acts and completed a questionnaire, including measures of the perceived legitimacy of videotaped aggression, of the teammates, coach, and self attitudes toward transgressions (modified TNQ), of the moral disengagement in sport (modified MDSS-S), and of self-reported aggressive behavior. A multilevel analysis confirmed a strong polarization effect on the perception of instrumental aggression, the videotaped aggressive acts appearing more tolerated in the collective than in the individual answering condition. Using a structural equation modeling, we found that the moral disengagement, which mediates the effects of perceived coach and ego attitudes toward transgressions, correlates positively with the tolerance of hostile aggression within teams, and with the level of aggressive acts reported by the participants. Aggr. Behav. Aggr. Behav. 42:123-133, 2015. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

  20. Head injuries presenting to emergency departments in the United States from 1990 to 1999 for ice hockey, soccer, and football.

    Delaney, J Scott

    2004-03-01

    To examine the number and rates of head injuries occurring in the community as a whole for the team sports of ice hockey, soccer, and football by analyzing data from patients presenting to US emergency departments (EDs) from 1990 to 1999. Retrospective analysis. Data compiled for the US Consumer Product Safety Commission using the National Electronic Injury Surveillance System were used to generate estimates for the total number of head injuries, concussions, internal head injuries, and skull fractures occurring on a national level from the years 1990 to 1999. These data were combined with yearly participation figures to generate rates of injuries presenting to the ED for each sport. There were an estimated 17,008 head injuries from ice hockey, 86,697 from soccer, and 204,802 from football that presented to US EDs from 1990 to 1999. The total number of concussions presenting to EDs in the United States over the same period was estimated to be 4820 from ice hockey, 21,715 from soccer, and 68,861 from football. While the rates of head injuries, concussions, and combined concussions/internal head injuries/skull fractures presenting to EDs per 10,000 players were not always statistically similar for all 3 sports in each year data were available, they were usually comparable. While the total numbers of head injuries, concussions, and combined concussions/skull fractures/internal head injuries presenting to EDs in the United States are different for ice hockey, soccer, and football for the years studied, the yearly rates for these injuries are comparable among all 3 sports.

  1. Less efficient oculomotor performance is associated with increased incidence of head impacts in high school ice hockey.

    Kiefer, Adam W; DiCesare, Christopher; Nalepka, Patrick; Foss, Kim Barber; Thomas, Staci; Myer, Gregory D

    2018-01-01

    To evaluate associations between pre-season oculomotor performance on visual tracking tasks and in-season head impact incidence during high school boys ice hockey. Prospective observational study design. Fifteen healthy high school aged male hockey athletes (M=16.50±1.17years) performed two 30s blocks each of a prosaccade and self-paced saccade task, and two trials each of a slow, medium, and fast smooth pursuit task (90°s -1 ; 180°s -1 ; 360°s -1 ) during the pre-season. Regular season in-game collision data were collected via helmet-mounted accelerometers. Simple linear regressions were used to examine relations between oculomotor performance measures and collision incidence at various impact thresholds. The variability of prosaccade latency was positively related to total collisions for the 20g force cutoff (p=0.046, adjusted R 2 =0.28). The average self-paced saccade velocity (p=0.020, adjusted R 2 =0.37) and variability of smooth pursuit gaze velocity (p=0.012, adjusted R 2 =0.47) were also positively associated with total collisions for the 50g force cutoff. These results provide preliminary evidence that less efficient oculomotor performance on three different oculomotor tasks is associated with increased incidence of head impacts during a competitive ice hockey season. The variability of prosaccade latency, the average self-paced saccade velocity and the variability of gaze velocity during predictable smooth pursuit all related to increased head impacts. Future work is needed to further understand player initiated collisions, but this is an important first step toward understanding strategies to reduce incidence of injury risk in ice hockey, and potentially contact sports more generally. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  2. Hockey Fans in Training: A Pilot Pragmatic Randomized Controlled Trial.

    Petrella, Robert J; Gill, Dawn P; Zou, Guangyong; DE Cruz, Ashleigh; Riggin, Brendan; Bartol, Cassandra; Danylchuk, Karen; Hunt, Kate; Wyke, Sally; Gray, Cindy M; Bunn, Christopher; Zwarenstein, Merrick

    2017-12-01

    Hockey Fans in Training (Hockey FIT) is a gender-sensitized weight loss and healthy lifestyle program. We investigated 1) feasibility of recruiting and retaining overweight and obese men into a pilot pragmatic randomized controlled trial and 2) potential for Hockey FIT to lead to weight loss and improvements in other outcomes at 12 wk and 12 months. Male fans of two ice hockey teams (35-65 yr; body mass index ≥28 kg·m) located in Ontario (Canada) were randomized to intervention (Hockey FIT) or comparator (wait-list control). Hockey FIT includes a 12-wk active phase (weekly, coach-led group meetings including provision of dietary information, practice of behavior change techniques, and safe exercise sessions plus incremental pedometer walking) and a 40-wk minimally supported phase (smartphone app for sustaining physical activity, private online social network, standardized e-mails, booster session/reunion). Measurement at baseline and 12 wk (both groups) and 12 months (intervention group only) included clinical outcomes (e.g., weight) and self-reported physical activity, diet, and self-rated health. Eighty men were recruited in 4 wk; trial retention was >80% at 12 wk and >75% at 12 months. At 12 wk, the intervention group lost 3.6 kg (95% confidence interval, -5.26 to -1.90 kg) more than the comparator group (P < 0.001) and maintained this weight loss to 12 months. The intervention group also demonstrated greater improvements in other clinical measures, physical activity, diet, and self-rated health at 12 wk; most sustained to 12 months. Results suggest feasible recruitment/retention of overweight and obese men in the Hockey FIT program. Results provide evidence for the potential effectiveness of Hockey FIT for weight loss and improved health in at-risk men and, thus, evidence to proceed with a definitive trial.

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

    Hichens, Michael; Drachen, Anders; Richards, Deborah

    2012-01-01

    The player character is an important feature of many games, where it is through the character that the player interacts with game world. There has been considerable interest in the relationship between the player and the player character. Much of this work has examined the identification of players......, third) as an indication of the relationship between player and character. Results indicate that the presence of story and information about the player character had no effect on identification with the plater character. However, characteristics of the players, particularly gender and general experience...... in playing video games, did have a statistically significant affect, indicating that different levels of identification are more dependent on the player than on the game. This indicates that players are not a homogeneous group with respect to player character identification and is an important consideration...

  4. Examining social identity and intrateam moral behaviours in competitive youth ice hockey using stimulated recall.

    Bruner, Mark W; Boardley, Ian D; Allan, Veronica; Root, Zach; Buckham, Sara; Forrest, Chris; Côté, Jean

    2017-10-01

    Social identity - identity formed through membership in groups - may play an important role in regulating intrateam moral behaviour in youth sport (Bruner, M. W., Boardley, I., & Côté, J. (2014). Social identity and prosocial and antisocial behavior in youth sport. Psychology of Sport and Exercise, 15(1), 56-64. doi:10.1016/j.psychsport.2013.09.003). The aim of this study was to qualitatively examine this potential role through stimulated recall interviews with competitive youth-ice-hockey players. Twenty-three players (M age  = 13.27 years, SD = 1.79) who reported engaging in high, median or low frequency of antisocial teammate behaviour (determined through pre-screening with the Prosocial and Antisocial Behaviour in Sport Scale [Kavussanu, M., & Boardley, I. D. (2009). The prosocial and antisocial behavior in sport scale. Journal of Sport and Exercise Psychology, 31(1), 97-117. doi:10.1123/jsep.31.1.97]) were recruited from eight youth-ice-hockey teams in Canada. Interviews involved participants recalling their thoughts during prosocial/antisocial interactions with teammates, prompted by previously recorded video sequences of such incidents. Thematic analysis of interview data revealed all athletes - regardless of reported frequency of intrateam antisocial behaviour - felt prosocial interactions with teammates enhanced social identity. In contrast, the perceived influence of antisocial teammate behaviour on social identity differed depending on athletes' reported frequency of intrateam antisocial behaviour; those reporting low and median frequencies described how such behaviour undermines social identity, whereas athletes reporting high frequency did not perceive this effect. The study findings highlight the potential importance of intrateam moral behaviour and social identity for youth-sport team functioning.

  5. Pozorování aktivity autonomního nervového systému prostřednictvím spektrální analýzy variability srdeční frekvence u hráčů ledního hokeje Autonomic nervous system observation through to use of spectral analysis of heart rate variability in ice hockey players

    Iva Řehová

    2007-01-01

    Full Text Available Cílem studie bylo poodhalit vliv pravidelného sportovního tréninku na aktivitu autonomního nervového systému (ANS, která byla hodnocena pomocí spektrální analýzy variability srdeční frekvence (SA HRV. K vyhodnocení výsledků SA HRV byly použity komplexní indexy (celkové skóre – TS, aktivita vagu – VA, sympatovagová balance – SVB a věkově standardizovaná hodnota celkového spektrálního výkonu (PT (Stejskal et al., 2002. Výzkumný soubor tvořili čtyři hráči ledního hokeje. Na základě získaných výsledků jsme došli k závěru, že kvalita sportovního tréninku ovlivňuje aktivitu ANS. Změny aktivity ANS, a tím velikosti adaptability sportovce, mohou významně ovlivnit sportovní výkon. Optimalizace adaptačních procesů prostřednictvím kontroly tréninkového zatížení na základě měření SA HRV může přinést nové aspekty řízení sportovního tréninku. The aim of our study was to investigate the infl uence of regular sport training on the activity of the autonomic nervous system (ANS and to disclose patterns of interrelations between them. The activity of the ANS was evaluated by means of the spectral analysis of heart rate variability (SA HRV. We used complex indices (total score – TS, vagal activity – VA, sympathovagal balance – SVB and age standardized values of total spectral power (PT for SA HRV results evaluation (Stejskal et al., 2002. The study group consisted of four ice hockey players, of whom all were 17 years old. The SA HRV was monitored by using VarCor PF7 hardware and VarCorMulti computer software, which enables four individuals to be measured at the same time. The examination of heart rate variability took place once a week in the morning. Information about the previous day’s training load, the duration and quality of sleep, and their self-reported health status (SRH was also obtained by completing a questionnaire before the SA HRV examination. Overall sports

  6. A Volunteer program guidebook for sport managers organizing large scale ice hockey tournaments

    Frison, Logan

    2010-01-01

    The guidebook is a tool to assist the tournament coordinator when recruting, training, and leading the best possible team of ice hockey volunteers to work at International Ice Hockey Federation (IIHF) tournaments and within the Sport Function - Ice Hockey events at Olympic Winter Games. The select volunteers are termed the ‘Ice Hockey Volunteers’ and consist of the six crews that make up the ‘Sport Team’ which work closely with the National Teams (athletes and team staff) and Officials (re...

  7. La eficacia del efecto látigo en el drag flick en el hockey hierba The effectiveness of the bullwhip effect in the Drag-flick in field hockey

    C. López de Subijana

    2010-09-01

    Full Text Available

    El penalty córner es una de las jugadas más importantes en el hockey hierba. El drag-flick es la técnica de golpeo más eficaz en las jugadas de penalty córner (McLaughin, 1997. Los objetivos del presente estudio fueron el describir los parámetros cinemáticos del drag-flick en jugadores de nivel internacional y analizar las diferencias intergénero. La muestra fueron trece sujetos, un modelo, seis hombres y seis mujeres. El sistema de captura automático VICON registró 20 lanzamientos de cada jugador con una frecuencia de muestreo de 250 Hz. Las velocidades máximas angulares de las caderas, hombros y stick  fueron superiores  (p<0.01 en el modelo que en ambos grupos de género. Mediante la comparación estadística del modelo con ambos grupos de género se han podido determinar las claves de este gesto técnico, siendo necesario un movimiento hacia atrás del stick (efecto látigo antes de la aceleración de caderas y hombros, para terminar el gesto con la máxima aceleración del stick.
    Palabras Clave: Biomecánica, drag-flick, hockey hierba, cinemática

    The penalty corner is one of the most important goal plays in field hockey. The drag-flick is more efficient than other techniques when playing a penalty corner. The aims of this study were to describe the kinematics of international field hockey players during the drag-flick and to analyse gender differences. Thirteen participants, one male drag-flicker, six males and six females participated in the study. VICON optoelectronic system measured the kinematic parameters from the drag-flick with six cameras sampling at 250 Hz. Twenty trials were captured from each subject. Ball velocity at release, hips maximum angular velocity, stick minimum and maximum angular velocities were higher (p<0.01 in the drag-flicker than in both gender groups. Comparing with the drag-flicker we have found the cues of the skill, being necessary a

  8. Anthropometric and Three-Compartment Body Composition Differences between Super League and Championship Rugby League Players: Considerations for the 2015 Season and Beyond.

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

    2015-01-01

    Super League (SL) and Championship (RLC) rugby league players will compete against each other in 2015 and beyond. To identify possible discrepancies, this study compared the anthropometric profile and body composition of current SL (full-time professional) and RLC (part-time semi-professional) players using dual-energy X-ray absorptiometry (DXA). A cross-sectional design involved DXA scans on 67 SL (n=29 backs, n=38 forwards) and 46 RLC (n=20 backs, n=26 forwards) players during preseason. A one-way ANOVA was used to compare age, stature, body mass, soft tissue fat percentage, bone mineral content (BMC), total and regional (i.e., arms, legs and trunk) fat and lean mass between SL forwards, SL backs, RLC forwards and RLC backs. No significant differences in age, stature or body mass were observed. SL forwards and backs had relatively less soft tissue fat (17.5 ± 3.7 and 14.8 ± 3.6 vs. 21.4 ± 4.3 and 20.8 ± 3.8%), greater BMC (4,528 ± 443 and 4,230 ± 447 vs. 4,302 ± 393 and 3,971 ± 280 g), greater trunk lean mass (37.3 ± 3.0 and 35.3 ± 3.8 vs. 34.9 ± 32.3 and 32.3 ± 2.6 kg) and less trunk fat mass (8.5 ± 2.7 and 6.2 ± 2.1 vs. 10.7 ± 2.8 and 9.5 ± 2.9 kg) than RLC forwards and backs. Observed differences may reflect selection based on favourable physical attributes, or training adaptations. To reduce this discrepancy, some RLC players should reduce fat mass and increase lean mass, which may be of benefit for the 2015 season and beyond.

  9. Anthropometric and Three-Compartment Body Composition Differences between Super League and Championship Rugby League Players: Considerations for the 2015 Season and Beyond.

    Ben Jones

    Full Text Available Super League (SL and Championship (RLC rugby league players will compete against each other in 2015 and beyond. To identify possible discrepancies, this study compared the anthropometric profile and body composition of current SL (full-time professional and RLC (part-time semi-professional players using dual-energy X-ray absorptiometry (DXA. A cross-sectional design involved DXA scans on 67 SL (n=29 backs, n=38 forwards and 46 RLC (n=20 backs, n=26 forwards players during preseason. A one-way ANOVA was used to compare age, stature, body mass, soft tissue fat percentage, bone mineral content (BMC, total and regional (i.e., arms, legs and trunk fat and lean mass between SL forwards, SL backs, RLC forwards and RLC backs. No significant differences in age, stature or body mass were observed. SL forwards and backs had relatively less soft tissue fat (17.5 ± 3.7 and 14.8 ± 3.6 vs. 21.4 ± 4.3 and 20.8 ± 3.8%, greater BMC (4,528 ± 443 and 4,230 ± 447 vs. 4,302 ± 393 and 3,971 ± 280 g, greater trunk lean mass (37.3 ± 3.0 and 35.3 ± 3.8 vs. 34.9 ± 32.3 and 32.3 ± 2.6 kg and less trunk fat mass (8.5 ± 2.7 and 6.2 ± 2.1 vs. 10.7 ± 2.8 and 9.5 ± 2.9 kg than RLC forwards and backs. Observed differences may reflect selection based on favourable physical attributes, or training adaptations. To reduce this discrepancy, some RLC players should reduce fat mass and increase lean mass, which may be of benefit for the 2015 season and beyond.

  10. Social Problems in Canadian Ice Hockey: An Exploration Through Film

    Fogel Curtis A.

    2014-12-01

    Full Text Available While celebrated as a highly popular sport in Canada, there are many social problems existing within and around Canadian ice hockey. These problems are often overlooked and rarely depicted in academic and journalistic research on sport. These social problems include, but are not limited to: extreme violence resulting in injuries and death, hazing rituals, multiple types of sexual violence, drug abuse, financial corruption, as well as various forms of prejudice and discrimination. Prompted by pop-cultural depictions in films, this paper further identifies and explores social problems in Canadian ice hockey revealing the realism embedded within various seemingly fictional films.

  11. Veto players

    Warntjen, Andreas; Dowding, Keith

    2010-01-01

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

  12. Three-dimensional kinematics of the lower limbs during forward ice hockey skating.

    Upjohn, Tegan; Turcotte, René; Pearsall, David J; Loh, Jonathan

    2008-05-01

    The objectives of the study were to describe lower limb kinematics in three dimensions during the forward skating stride in hockey players and to contrast skating techniques between low- and high-calibre skaters. Participant motions were recorded with four synchronized digital video cameras while wearing reflective marker triads on the thighs, shanks, and skates. Participants skated on a specialized treadmill with a polyethylene slat bed at a self-selected speed for 1 min. Each participant completed three 1-min skating trials separated by 5 min of rest. Joint and limb segment angles were calculated within the local (anatomical) and global reference planes. Similar gross movement patterns and stride rates were observed; however, high-calibre participants showed a greater range and rate of joint motion in both the sagittal and frontal planes, contributing to greater stride length for high-calibre players. Furthermore, consequent postural differences led to greater lateral excursion during the power stroke in high-calibre skaters. In conclusion, specific kinematic differences in both joint and limb segment angle movement patterns were observed between low- and high-calibre skaters.

  13. Is hockey just a game? Contesting meanings of the ice hockey life projects through a career-threatening injury

    Ronkainen, Noora J.; Ryba, Tatiana V.

    2017-01-01

    This study is situated within an existential–narrative theoretical framework to examine the impact of career-threatening injury on professional ice hockey players’ well-being and career construction. Professional ice hockey culture is construed as a privileged space characterised by hegemonic...... masculinity, fierce competition as well as high-risk behaviours often resulting in sports injuries. In this paper, we analyse two players’ life stories with a particular focus on injury as a boundary situation involving social and temporal breakdown and re-evaluation of meaning of sporting life projects...

  14. Considerations in the Diagnosis and Accelerated Return to Sport of a Professional Basketball Player With a Triceps Surae Injury: A Case Report.

    Anloague, Philip A; Strack, Donald S

    2018-05-01

    Study Design Case report. Background Acute injuries of the triceps surae and Achilles tendon are common in sports. Rupture of the plantaris tendon can be challenging to diagnose. There is limited evidence detailing the diagnosis, rehabilitation, and accelerated return to sport of elite professional basketball players who have sustained calf injuries. Case Description A 25-year-old male professional basketball player sustained an injury to his calf during a professional basketball game. This case report details the presumptive diagnosis, graduated progression of intervention, and return to play of a professional athlete with a likely isolated plantaris tendon tear. Outcomes The patient returned to postseason competition 10 days post injury. Objective measures were tracked throughout rehabilitation and compared to baseline assessments. Before returning to play, the athlete showed improvements beyond the minimal clinically important difference for calf girth (2 cm) and numeric pain-rating scale score (4 points, 0-10 scale). Functional testing was conducted that included the Y Balance Test lower quarter and the Functional Movement Screen, with results that exceeded or returned the athlete to preseason levels. Discussion This report details the case of a professional basketball player who returned to competitive play in an accelerated time frame following injury to his calf. Diagnosing a plantaris tendon rupture can be challenging, and anatomical variations of this muscle should be considered. It was demonstrated in this case that physical therapy rehabilitation was helpful in making a treatment-based clinical diagnosis when imaging was unclear. Level of Evidence Therapy, level 5. J Orthop Sports Phys Ther 2018;48(5):388-397. Epub 6 Apr 2018. doi:10.2519/jospt.2018.7192.

  15. A Hockey Night in Canada: An Imagined Conversation between Theorists

    Fogel, Curtis

    2010-01-01

    In this paper, various methodological issues surrounding the sociological study of sport are explored. Through an imagined dialogue between two graduate students at a hockey game, this work brings together three divergent approaches to social enquiry: Positivist Grounded Theory, Constructivist Grounded Theory, and Actor-Network Theory. This paper…

  16. Ice hockey arena: national pride or normal business?

    Münich, Daniel; Humphreys, B. R.

    2002-01-01

    Roč. 7, č. 6 (2002), s. 11 ISSN 1211-3514 Institutional research plan: CEZ:AV0Z7085904 Keywords : ice hockey arena * costs and benefits Subject RIV: AH - Economics http://search.ebscohost.com/login.aspx?direct=true&db=bth&AN=6129219&site=ehost-live

  17. Mild Dehydration Does Not Influence Performance Or Skeletal Muscle Metabolism During Simulated Ice Hockey Exercise In Men.

    Palmer, Matthew S; Heigenhauser, George J F; Duong, MyLinh; Spriet, Lawrence L

    2017-04-01

    This study determined whether mild dehydration influenced skeletal muscle glycogen use, core temperature or performance during high-intensity, intermittent cycle-based exercise in ice hockey players vs. staying hydrated with water. Eight males (21.6 ± 0.4 yr, 183.5 ± 1.6 cm, 83.9 ± 3.7 kg, 50.2 ± 1.9 ml·kg -1 ·min -1 ) performed two trials separated by 7 days. The protocol consisted of 3 periods (P) containing 10 × 45-s cycling bouts at ~133% VO 2max , followed by 135 s of passive rest. Subjects drank no fluid and dehydrated during the protocol (NF), or maintained body mass by drinking WATER. Muscle biopsies were taken at rest, immediately before and after P3. Subjects were mildly dehydrated (-1.8% BM) at the end of P3 in the NF trial. There were no differences between the NF and WATER trials for glycogen use (P1+P2; 350.1 ± 31.9 vs. 413.2 ± 33.2, P3; 103.5 ± 16.2 vs. 131.5 ± 18.9 mmol·kg dm -1 ), core temperature (P1; 37.8 ± 0.1 vs. 37.7 ± 0.1, P2; 38.2 ± 0.1 vs. 38.1 ± 0.1, P3; 38.3 ± 0.1 vs. 38.2 ± 0.1 °C) or performance (P1; 156.3 ± 7.8 vs. 154.4 ± 8.2, P2; 150.5 ± 7.8 vs. 152.4 ± 8.3, P3; 144.1 ± 8.7 vs. 148.4 ± 8.7 kJ). This study demonstrated that typical dehydration experienced by ice hockey players (~1.8% BM loss), did not affect glycogen use, core temperature, or voluntary performance vs. staying hydrated by ingesting water during a cycle-based simulation of ice hockey exercise in a laboratory environment.

  18. Low back pain in young elite field hockey players, football players and speed skaters: Prevalence and risk factors

    van Hilst, Jony; Hilgersom, Nick F. J.; Kuilman, Miriam C.; F M Kuijer, P. Paul; Frings-Dresen, Monique H. W.

    2015-01-01

    Low back pain (LBP) hampers performance and experiencing an episode of LBP is strongly associated with recurrent episodes. The prevalence of LBP and associated risk factors among young elite athletes in popular sports in the Netherlands were studied. A questionnaire-based cross-sectional study was

  19. A systematic video analysis of National Hockey League (NHL) concussions, part II: how concussions occur in the NHL.

    Hutchison, Michael G; Comper, Paul; Meeuwisse, Willem H; Echemendia, Ruben J

    2015-04-01

    Concussions in sports are a growing cause of concern, as these injuries can have debilitating short-term effects and little is known about the potential long-term consequences. This work aims to describe how concussions occur in the National Hockey League. Case series of medically diagnosed concussions for regular season games over a 3.5-year period during the 2006-2010 seasons. Digital video records were coded and analysed using a standardised protocol. 88% (n=174/197) of concussions involved player-to-opponent contact. 16 diagnosed concussions were a result of fighting. Of the 158 concussions that involved player-to-opponent body contact, the most common mechanisms were direct contact to the head initiated by the shoulder 42% of the time (n=66/158), by the elbow 15% (n=24/158) and by gloves in 5% of cases (n=8/158). When the results of anatomical location are combined with initial contact, almost half of these events (n=74/158) were classified as direct contact to the lateral aspect of the head. The predominant mechanism of concussion was consistently characterised by player-to-opponent contact, typically directed to the head by the shoulder, elbow or gloves. Also, several important characteristics were apparent: (1) contact was often to the lateral aspect of the head; (2) the player who suffered a concussion was often not in possession of the puck and (3) no penalty was called on the play. 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.

  20. Sex differences in white matter alterations following repetitive subconcussive head impacts in collegiate ice hockey players

    Nico Sollmann

    2018-01-01

    Conclusions: The results of this study suggest sex differences in structural alterations following exposure to RSHI. Future studies need to investigate further the underlying mechanisms and association with exposure and clinical outcomes.

  1. Allometric scaling of peak oxygen uptake in male roller hockey players under 17 years old

    Valente-dos-Santos, J.; Sherar, L.; Coelho-e-Silva, MJ; Pereira, J.R.; Vaz, V.; Cupido-dos-Santos, A.; Baxter-Jones, A.; Visscher, C.; Elferink-Gemser, M.T.; Malina, R.M.

    Peak oxygen uptake ((V) over dotO(2peak)) is routinely expressed in litres per minute and by unit of body mass (mL.kg(-1).min(-1)) despite the theoretical and statistical limitations of using ratios. Allometric modeling is an effective approach for partitioning body-size effects in a performance

  2. Quantum Two Player Game in Thermal Environment.

    Jerzy Dajka

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

  3. Cardiovascular Response to Recreational Hockey in Middle-Aged Men.

    Goodman, Zack A; Thomas, Scott G; Wald, Robert C; Goodman, Jack M

    2017-06-15

    The present study examined the hemodynamic response to recreational pick-up hockey relative to maximal exercise testing in middle-aged men. A total of 23 men with a mean age of 53 ± 7 years were studied. Graded exercise testing on a cycle ergometer determined maximal oxygen consumption, blood pressure (BP), and heart rate (HR). Ambulatory BP and Holter electrocardiographic monitoring was performed during one of their weekly hockey games (mean duration = 45 ± 7.2 minutes): for "On-Ice" responses (PLAY; data recorded while standing immediately after a shift; 8.0 ± 1.4 shifts per game) and during seated recovery (BENCH), 15 minutes after the game. On-Ice HRs and BPs were significantly higher than values obtained during maximal cycle exercise, respectively (HR 174 ± 8.9 vs 163 ± 11.0 beats/min) (systolic blood pressure 202 ± 20 vs 173 ± 31 mm Hg; p game, whereas HR increased from 139 ± 20 to 155 ± 16 beats/min during the game. The myocardial oxygen demand (myocardial time tension index) increased significantly during PLAY concurrent with a decrease in estimated myocardial oxygen supply (diastolic pressure time index), with the endocardial viability ratio during PLAY demonstrating a significant decrease during the third quarter of the game (1.25 ± 0.24) versus the first quarter (1.56 ± 0.30), which remained depressed 15 minutes post-game (p men is an extremely vigorous interval exercise with increasing relative intensity as the game progresses. Hockey elicits peak BPs and HRs that can exceed values observed during maximal exercise testing and is characterized by progressive increases in myocardial oxygen demand and lowered supply during PLAY and BENCH time. Given the progressive and high cardiovascular demands, caution is warranted when estimating the cardiovascular demands of hockey from clinical stress testing, particularly in those whom coronary reserve may be compromised. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    Manuel Jacob Sierra-Díaz

    2017-01-01

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

  5. Laboratory- and field-based testing as predictors of skating performance in competitive-level female ice hockey.

    Henriksson, Tommy; Vescovi, Jason D; Fjellman-Wiklund, Anncristine; Gilenstam, Kajsa

    2016-01-01

    The purpose of this study was to examine whether field-based and/or laboratory-based assessments are valid tools for predicting key performance characteristics of skating in competitive-level female hockey players. Cross-sectional study. Twenty-three female ice hockey players aged 15-25 years (body mass: 66.1±6.3 kg; height: 169.5±5.5 cm), with 10.6±3.2 years playing experience volunteered to participate in the study. The field-based assessments included 20 m sprint, squat jump, countermovement jump, 30-second repeated jump test, standing long jump, single-leg standing long jump, 20 m shuttle run test, isometric leg pull, one-repetition maximum bench press, and one-repetition maximum squats. The laboratory-based assessments included body composition (dual energy X-ray absorptiometry), maximal aerobic power, and isokinetic strength (Biodex). The on-ice tests included agility cornering s-turn, cone agility skate, transition agility skate, and modified repeat skate sprint. Data were analyzed using stepwise multivariate linear regression analysis. Linear regression analysis was used to establish the relationship between key performance characteristics of skating and the predictor variables. Regression models (adj R (2)) for the on-ice variables ranged from 0.244 to 0.663 for the field-based assessments and from 0.136 to 0.420 for the laboratory-based assessments. Single-leg tests were the strongest predictors for key performance characteristics of skating. Single leg standing long jump alone explained 57.1%, 38.1%, and 29.1% of the variance in skating time during transition agility skate, agility cornering s-turn, and modified repeat skate sprint, respectively. Isokinetic peak torque in the quadriceps at 90° explained 42.0% and 32.2% of the variance in skating time during agility cornering s-turn and modified repeat skate sprint, respectively. Field-based assessments, particularly single-leg tests, are an adequate substitute to more expensive and time

  6. A survey of mental skills training among South African field hockey ...

    African Journal for Physical Activity and Health Sciences ... observed for concentration, achievement motivation and activation control. ... The participants in the study perceived MST as an important tool to enhance performance in field hockey.

  7. Development of offensive individual game skills and offensive game combinations in ice hockey

    Janek, Michael

    2015-01-01

    Title: Development of offensive individual game skills and offensive game combinations in ice hockey Goals: The main aim of this thesis is to gather theoretical information about development and improvement of offensive individual game skills and offensive game combinations in ice hockey and suggest essential and key exercises of this issue. Methods: The thesis was primarily written with the use of searching method based on information from available expert literature, electronic sources and ...

  8. Analisys and energy saving measures of kastvallen ice hockey rink arena

    Igual Bueno, Mario; Bielsa Azcona, José Enrique

    2011-01-01

    Nowadays efficiency measures are more and more important because the price of the energy is increasing every year. Moreover, saving energy it is also important for decrease the environmental impact. Kastvallen is a hockey arena built in 1997 that cools the hockey rink with electric compressors. The changing rooms are heating by using district heating. Actually the total invoice of electricity is above the 800000 SEK. Meanwhile the district heating invoice reaches the 60000SE...

  9. Return to play after an initial or recurrent concussion in a prospective study of physician-observed junior ice hockey concussions: implications for return to play after a concussion.

    Echlin, Paul Sean; Tator, Charles H; Cusimano, Michael D; Cantu, Robert C; Taunton, Jack E; Upshur, Ross E G; Czarnota, Michael; Hall, Craig R; Johnson, Andrew M; Forwell, Lorie A; Driediger, Molly; Skopelja, Elaine N

    2010-11-01

    The authors investigated return-to-play duration for initial and recurrent concussion in the same season in 2 teams of junior (16-21-year-old) ice hockey players during a regular season. The authors conducted a prospective cohort study during 1 junior regular season (2009-2010) of 67 male fourth-tier ice hockey players (mean age 18.2 ± 1.2 years [SD], range 16-21 years) from 2 teams. Prior to the start of the season, every player underwent baseline assessments that were determined using the Sideline Concussion Assessment Tool 2 (SCAT2) and the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT). The study protocol also required players who entered the study during the season to complete a baseline SCAT2 and ImPACT. If the protocol was not followed, the postinjury test results of a player without true baseline test results were compared with previously established age- and sex-matched group normative levels. Each game was directly observed by a physician and at least 1 neutral nonphysician observer. Players suspected of suffering a concussion were evaluated by the physician during the game. If a concussion was diagnosed, the player underwent clinical evaluation at the physician's office within 24 hours. The return-to-play decision was based on clinical evaluation guided by the Zurich return-to-play protocol (contained in the consensus statement of international expert opinion at the 3rd International Conference on Concussion in Sport held in Zurich, November 2008). This clinical evaluation and return-to-play protocol was augmented by the 2 tests (SCAT2 and ImPACT) also recommended by the Zurich consensus statement, for which baseline values had been obtained. Seventeen players sustained a physician-observed or self-reported, physician-diagnosed concussion during a physician-observed ice hockey game. The mean clinical return-to-play duration (in 15 cases) was 12.8 ± 7.02 days (median 10 days, range 7-29 days); the mean number of physician office visits

  10. Exploring Gaps in Concussion Knowledge and Knowledge Translation Among Coaches of Youth Female Hockey.

    Guo, David; Verweel, Lee; Reed, Nick

    2017-10-27

    To better understand the level of concussion knowledge of youth female hockey coaches and to identify preferred methods of knowledge translation for this population. Cross-sectional survey. Participants independently completed written surveys before in-person concussion information sessions or online surveys through link provided in emails. Convenience sampling yielded 130 coaches of youth female hockey from Canada. Knowledge level on concussion, resources from which coaches obtained information on concussion, opinions on the current level of concussion knowledge, and knowledge translation. Coaches demonstrated adequate knowledge on concussion, achieving 84% correct on true-false questions and 92% correct on symptom identification accuracy. However, coaches showed limited awareness of concussion specific to mechanisms for injury (identification) and postconcussion symptoms. Internet resources were rated as the most used resources for concussion yet were not rated very helpful. Nonetheless, coaches indicated online courses and web sites as the most preferred method for concussion knowledge translation. Youth female hockey coaches have overall adequate knowledge of concussion; however, gaps in knowledge do exist. Future efforts to raise the concussion knowledge among coaches of female youth hockey should include information specific to the mechanism of injury, along with sign and symptom identification, with particular attention paid to emotional symptoms. Given the reported preferences and the widespread availability of the Internet, further exploration and research validation of online courses and web sites tailored to the youth female hockey community is encouraged.

  11. Individual Alpha Peak Frequency in Ice Hockey Shooting Performance

    Sommer Christie

    2017-05-01

    Full Text Available There are several important inter- and intra-individual variations in individual alpha peak frequency (IAPF in the cognitive domain. The rationale for the present study was to extend the research on IAPF in the cognitive domain to IAPF in the sport domain. Specifically, the purpose of the present study was twofold: (a to explore whether baseline IAPF is related to performance in an ice hockey shooting task and (b to explore whether a shooting task has an effect on IAPF variability. The present investigation is one of the first studies to examine links between IAPF and sport performance. Study results did not show significant changes in IAPF when comparing baseline IAPF and pre- to post-task IAPF across three performance levels. The findings support previous literature in the cognitive domain suggesting that IAPF is a stable neurophysiological marker. Future research should consider the following methodological suggestions: (a measuring IAPF during sport performance instead of at a resting state, (b changing the pre-performance resting baseline instructions to take into account sport-specific mental preparation, (c exploring an expert-novice paradigm to accentuate performance ability differences between groups (d comparing tasks with different levels of complexity, and (e analyzing the possible correlation between IAPF and performance on different days.

  12. Gaze characteristics of elite and near-elite athletes in ice hockey defensive tactics.

    Martell, Stephen G; Vickers, Joan N

    2004-04-01

    Traditional visual search experiments, where the researcher pre-selects video-based scenes for the participant to respond to, shows that elite players make more efficient decisions than non-elites, but disagree on how they temporally regulate their gaze. Using the vision-in-action [J.N. Vickers, J. Exp. Psychol.: Human Percept. Perform. 22 (1996) 342] approach, we tested whether the significant gaze that differentiates elite and non-elite athletes occurred either: early in the task and was of more rapid duration [A.M. Williams et al., Res. Quart. Exer. Sport 65 (1994) 127; A.M. Williams and K. Davids, Res. Quart. Exer. Sport 69 (1998) 111], or late in the task and was of longer duration [W. Helsen, J.M. Pauwels, A cognitive approach to visual search in sport, in: D. Brogan, K. Carr (Eds.), Visual Search, vol. II, Taylor and Francis, London, 1992], or whether a more complex gaze control strategy was used that consisted of both early and rapid fixations followed by a late fixation of long duration prior to the final execution. We tested this using a live defensive zone task in ice hockey. Results indicated that athletes temporally regulated their gaze using two different gaze control strategies. First, fixation/tracking (F/T) gaze early in the trial were significantly shorter than the final F/T and confirmed that the elite group fixated the tactical locations more rapidly than the non-elite on successful plays. And secondly, the final F/T prior to critical movement initiation (i.e. F/T-1) was significantly longer for both groups, averaging 30% of the final part of the phase and occurred as the athletes isolated a single object or location to end the play. The results imply that expertise in defensive tactics is defined by a cascade of F/T, which began with the athletes fixating or tracking specific locations for short durations at the beginning of the play, and concluded with a final gaze of long duration to a relatively stable target at the end. The results are

  13. Lesbian erotics at women's hockey: fans, flashing, and the Booby Orrs.

    Davidson, Judy

    2009-01-01

    This article analyzes a public breast flashing event that occurred during the women's ice hockey tournament at the OutGames/Western Cup Lesbigay athletic event in 2007. Employing a postfoundational perspective, I first contextualize the ice hockey subculture of the team called the Booby Orrs, outlining some of our history, norms, and context. I then tell the particular story that leads to our fans flashing their breasts as we finally scored some goals. I end with my analysis of this event: how a public nude display of sexualized women's breasts in a lesbian-coded public space prompted a resistant sporting moment, at least contingently.

  14. Novel hockey-stick mesogens with the nematic, synclinic and anticlinic smectic C phase sequence

    Novotná, Vladimíra; Žurek, J.; Kozmik, V.; Svoboda, J.; Glogarová, Milada; Kroupa, Jan; Pociecha, D.

    2008-01-01

    Roč. 35, č. 8 (2008), 1023-1036 ISSN 0267-8292 R&D Projects: GA AV ČR IAA100100710 Institutional research plan: CEZ:AV0Z10100520 Keywords : liquid crystals * synclinic and anticlinic ordering * hockey-stick mezogens Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.132, year: 2008

  15. Describing Strategies Used by Elite, Intermediate, and Novice Ice Hockey Referees

    Hancock, David J.; Ste-Marie, Diane M.

    2014-01-01

    Much is known about sport officials' decisions (e.g., anticipation, visual search, and prior experience). Comprehension of the entire decision process, however, requires an ecologically valid examination. To address this, we implemented a 2-part study using an expertise paradigm with ice hockey referees. Purpose: Study 1 explored the…

  16. Understanding the resistance to creating safer ice hockey: essential points for injury prevention.

    Todd, Ryan A; Soklaridis, Sophie; Treen, Alice K; Bhalerao, Shree U; Cusimano, Michael D

    2017-11-27

    Despite the known negative health outcomes of concussions in minor level boys' hockey, there has been significant resistance to creating a safer game with less body checking. To better understand cultural barriers that prevent making the sport safer for youth and adolescents, semistructured interviews, with 20 ice hockey stakeholders, were conducted and analysed using thematic analysis. Through this analysis, two primary concepts arose from respondents. The first concept is that body checking, despite the harm it can cause, should be done in a respectful sportsmanlike fashion. The second concept is the contradiction that the game of ice hockey is both dynamic and unchangeable. Using structural functionalist theory, we propose an argument that the unfortunate perpetuation of violence and body checking in youth ice hockey serves to maintain the social order of the game and its culture. Any strategies aimed at modifying and promoting healthy behaviour in the game should take these concepts into account. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  17. An Examination of the Relative Age Effect in Developmental Girls' Hockey in Ontario

    Smith, Kristy L.; Weir, Patricia L.

    2013-01-01

    The relative age effect (RAE) suggests that athletes may be provided with greater opportunities for success depending on the position of their birthdate in a sport's selection year. While the effect has been well established in men's sports, less is known about women's sports. This study examined the RAE in developmental girls' hockey in Ontario.…

  18. Hockey, iPads, and Projectile Motion in a Physics Classroom

    Hechter, Richard P.

    2013-01-01

    With the increased availability of modern technology and handheld probeware for classrooms, the iPad and the Video Physics application developed by Vernier are used to capture and analyze the motion of an ice hockey puck within secondary-level physics education. Students collect, analyze, and generate digital modes of representation of physics…

  19. Laboratory- and field-based testing as predictors of skating performance in competitive-level female ice hockey

    Henriksson T

    2016-08-01

    Full Text Available Tommy Henriksson,1,2 Jason D Vescovi,3 Anncristine Fjellman-Wiklund,4 Kajsa Gilenstam1 1Sport Medicine Unit, Department of Community Medicine and Rehabilitation, 2The National Graduate School of Gender Studies, Umeå University, Umeå, Sweden; 3Faculty of Kinesiology and Physical Education, University of Toronto, Toronto, ON, Canada; 4Physiotherapy Unit, Department of Community Medicine and Rehabilitation, Umeå University, Umeå, Sweden Objectives: The purpose of this study was to examine whether field-based and/or laboratory-based assessments are valid tools for predicting key performance characteristics of skating in competitive-level female hockey players.Design: Cross-sectional study.Methods: Twenty-three female ice hockey players aged 15–25 years (body mass: 66.1±6.3 kg; height: 169.5±5.5 cm, with 10.6±3.2 years playing experience volunteered to participate in the study. The field-based assessments included 20 m sprint, squat jump, countermovement jump, 30-second repeated jump test, standing long jump, single-leg standing long jump, 20 m shuttle run test, isometric leg pull, one-repetition maximum bench press, and one-repetition maximum squats. The laboratory-based assessments included body composition (dual energy X-ray absorptiometry, maximal aerobic power, and isokinetic strength (Biodex. The on-ice tests included agility cornering s-turn, cone agility skate, transition agility skate, and modified repeat skate sprint. Data were analyzed using stepwise multivariate linear regression analysis. Linear regression analysis was used to establish the relationship between key performance characteristics of skating and the predictor variables.Results: Regression models (adj R2 for the on-ice variables ranged from 0.244 to 0.663 for the field-based assessments and from 0.136 to 0.420 for the laboratory-based assessments. Single-leg tests were the strongest predictors for key performance characteristics of skating. Single leg standing

  20. Mass carbon monoxide poisoning at an ice-hockey game: initial approach and long-term follow-up.

    Mortelmans, Luc J M; Populaire, Jacques; Desruelles, Didier; Sabbe, Marc B

    2013-12-01

    A mass carbon monoxide (CO) intoxication during an ice-hockey game is described. Two hundred and thirty-five patients were seen in different hospitals, 88 of them the same night at the nearby emergency department. To evaluate long-term implications and to identify relevant indicators, a follow-up study was organized 1 year after the incident. Apart from the file data from the emergency departments, a 1-year follow-up mailing was sent to all patients. One hundred and ninety-one patients returned their questionnaire (86%). The mean age of the patients was 28 years, with 61% men. The mean carboxyhaemoglobin (COHb) was 9.9%. COHb levels were significantly higher for individuals on the ice (referee, players and maintenance personnel). There was a significant relationship with the initial presence of dizziness, fatigue and the COHb level. Headache, abdominal pain, nausea and vomiting were not significantly related to the COHb levels. The relationship between symptoms and CO level, however, should be interpreted with caution as there was a wide range between exposure and blood tests. 5.2% of patients had residual complaints, all including headache, with a significant higher incidence with high COHb levels. Only two patients had an abnormal neurological control (one slightly disturbed electroencephalography and one persistent encephalopathic complaint). Work incapacity was also significantly related to COHb levels. CO mass poisonings remain a risk in indoor sporting events. Although it causes an acute mass casualty incident, it is limited in time and delayed problems are scarce. Symptomatology is a poor tool for triage. The best prevention is the use of nonmineral energy sources such as for example electricity.

  1. Estudio etnográfico del portero de hockey sobre patines: una vida entre paradojas

    Guillem Trabal Tañá

    2016-12-01

    Full Text Available Este estudio es la primera investigación en las ciencias de la actividad física y el deporte que ha analizado desde una perspectiva etnográfica el portero de hockey sobre patines. El objetivo principal es conocer cuáles son las valoraciones y los juicios que la comunidad del hockey sobre patines ha otorgado a esta figura y poder comprender cuál es la lógica externa existente a su alrededor. La metodología utilizada en este estudio ha sido la observación, la observación participante y 8 entrevistas en profundidad a porteros, jugadores y entrenadores de la máxima categoría del hockey sobre patines nacional. Los principales resultados muestran que: a el portero es considerado el jugador más determinante del equipo; b los juicios que se hacen de las actuaciones del portero tienen en cuenta variables cuantitativas: los goles encajados y el resultado final de un partido y/o competición; c dentro de la comunidad del hockey sobre patines se ha enquistado una definición de la identidad del portero que lo asocia a la locura, la soledad, la extravagancia y la rareza; d los porteros comparten una forma particular de comprender este deporte que fundamenta su asociación y su cooperación, y e la existencia del portero dentro del hockey sobre patines está llena de paradojas que se contraponen a la alta importancia atribuida a esta figura.

  2. The hockey-stick method to estimate evening dim light melatonin onset (DLMO) in humans.

    Danilenko, Konstantin V; Verevkin, Evgeniy G; Antyufeev, Viktor S; Wirz-Justice, Anna; Cajochen, Christian

    2014-04-01

    The onset of melatonin secretion in the evening is the most reliable and most widely used index of circadian timing in humans. Saliva (or plasma) is usually sampled every 0.5-1 hours under dim-light conditions in the evening 5-6 hours before usual bedtime to assess the dim-light melatonin onset (DLMO). For many years, attempts have been made to find a reliable objective determination of melatonin onset time either by fixed or dynamic threshold approaches. The here-developed hockey-stick algorithm, used as an interactive computer-based approach, fits the evening melatonin profile by a piecewise linear-parabolic function represented as a straight line switching to the branch of a parabola. The switch point is considered to reliably estimate melatonin rise time. We applied the hockey-stick method to 109 half-hourly melatonin profiles to assess the DLMOs and compared these estimates to visual ratings from three experts in the field. The DLMOs of 103 profiles were considered to be clearly quantifiable. The hockey-stick DLMO estimates were on average 4 minutes earlier than the experts' estimates, with a range of -27 to +13 minutes; in 47% of the cases the difference fell within ±5 minutes, in 98% within -20 to +13 minutes. The raters' and hockey-stick estimates showed poor accordance with DLMOs defined by threshold methods. Thus, the hockey-stick algorithm is a reliable objective method to estimate melatonin rise time, which does not depend on a threshold value and is free from errors arising from differences in subjective circadian phase estimates. The method is available as a computerized program that can be easily used in research settings and clinical practice either for salivary or plasma melatonin values.

  3. Scheduling for the National Hockey League Using a Multi-objective Evolutionary Algorithm

    Craig, Sam; While, Lyndon; Barone, Luigi

    We describe a multi-objective evolutionary algorithm that derives schedules for the National Hockey League according to three objectives: minimising the teams' total travel, promoting equity in rest time between games, and minimising long streaks of home or away games. Experiments show that the system is able to derive schedules that beat the 2008-9 NHL schedule in all objectives simultaneously, and that it returns a set of schedules that offer a range of trade-offs across the objectives.

  4. The positioning of federate sports in Portugal: handball, basketball, roller hockey and volleyball

    Gonçalves, Celina; Correia, Abel

    2005-01-01

    Sport is constituted by a multiplicity of activities with different purposes, concepts and cultural representations. Before the increase of supply, Sports Federations need to understand the practitioners in relation to the several possibilities of practice and to position their sports according to their competitors. In this context, the purpose of this study is the positioning of team federate sports (handball, basketball, roller hockey and volleyball). According to Lindon et al.,...

  5. Comparison of effectiveness of advertising expenses during broadcasts of main hockey events

    Kozlová, Natálie

    2017-01-01

    Title: Comparison of effectiveness of advertising expenses during broadcasts of main hockey events Objectives: The main goal of this dissertation is to compare the amount of money invested into the commercial advertisement during sport broadcasts at the ČT sport channel with viewer ratings. The used metric is a coefficient computed as a ratio between the viewer rating of the particular broadcast and the corresponding advertisement cost, normalized using Cost per Thousand method. Another goal ...

  6. Acute injuries in soccer, ice hockey, volleyball, basketball, judo, and karate: analysis of national registry data.

    Kujala, U. M.; Taimela, S.; Antti-Poika, I.; Orava, S.; Tuominen, R.; Myllynen, P.

    1995-01-01

    OBJECTIVE--To determine the acute injury profile in each of six sports and compare the injury rates between the sports. DESIGN--Analysis of national sports injury insurance registry data. SETTING--Finland during 1987-91. SUBJECTS--621,691 person years of exposure among participants in soccer, ice hockey, volleyball, basketball, judo, or karate. MAIN OUTCOME MEASURES--Acute sports injuries requiring medical treatment and reported to the insurance company on structured forms by the patients and...

  7. Does self-confidence link to motivation? A study in field hockey athletes

    Sari, İhsan; Ekici, Sümmani; Soyer, Fikret; Eskiler, Ersin

    2015-01-01

    Previous research indicated some evidence of a positive relationship between motivation and self-efficacy beliefs/perceived competence/self-perceptions. Therefore, the relationship between self-confidence and motivation was investigated in sport context in this study. Participants of this study were 111 field hockey athletes. Sport Motivation Scale (Pelletier et al., 1995) and Self-confidence Scales (Tokinan, 2008) were used for data collection. SPSS.17 package program was used to analyse the...

  8. Acute injuries in soccer, ice hockey, volleyball, basketball, judo, and karate: analysis of national registry data.

    Kujala, U. M.; Taimela, S.; Antti-Poika, I.; Orava, S.; Tuominen, R.; Myllynen, P.

    1995-01-01

    OBJECTIVE--To determine the acute injury profile in each of six sports and compare the injury rates between the sports. DESIGN--Analysis of national sports injury insurance registry data. SETTING--Finland during 1987-91. SUBJECTS--621,691 person years of exposure among participants in soccer, ice hockey, volleyball, basketball, judo, or karate. MAIN OUTCOME MEASURES--Acute sports injuries requiring medical treatment and reported to the insurance company on structured forms by the patients and their doctors. RESULTS--54,186 sports injuries were recorded. Injury rates were low in athletes aged under 15, while 20-24 year olds had the highest rates. Differences in injury rates between the sports were minor in this adult age group. Overall injury rates were higher in sports entailing more frequent and powerful body contact. Each sport had a specific injury profile. Fractures and dental injuries were most common in ice hockey and karate and least frequent in volleyball. Knee injuries were the most common cause of permanent disability. CONCLUSIONS--Based on the defined injury profiles in the different sports it is recommended that sports specific preventive measures should be employed to decrease the number of violent contacts between athletes, including improved game rules supported by careful refereeing. To prevent dental injuries the wearing of mouth guards should be encouraged, especially in ice hockey, karate, and basketball. PMID:8520333

  9. Acute injuries in soccer, ice hockey, volleyball, basketball, judo, and karate: analysis of national registry data.

    Kujala, U M; Taimela, S; Antti-Poika, I; Orava, S; Tuominen, R; Myllynen, P

    1995-12-02

    To determine the acute injury profile in each of six sports and compare the injury rates between the sports. Analysis of national sports injury insurance registry data. Finland during 1987-91. 621,691 person years of exposure among participants in soccer, ice hockey, volleyball, basketball, judo, or karate. Acute sports injuries requiring medical treatment and reported to the insurance company on structured forms by the patients and their doctors. 54,186 sports injuries were recorded. Injury rates were low in athletes aged under 15, while 20-24 year olds had the highest rates. Differences in injury rates between the sports were minor in this adult age group. Overall injury rates were higher in sports entailing more frequent and powerful body contact. Each sport had a specific injury profile. Fractures and dental injuries were most common in ice hockey and karate and least frequent in volleyball. Knee injuries were the most common cause of permanent disability. Based on the defined injury profiles in the different sports it is recommended that sports specific preventive measures should be employed to decrease the number of violent contacts between athletes, including improved game rules supported by careful refereeing. To prevent dental injuries the wearing of mouth guards should be encouraged, especially in ice hockey, karate, and basketball.

  10. Investigating the Nutritional and Recovery Habits of Tennis Players

    James A. Fleming

    2018-04-01

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

  11. Investigating the Nutritional and Recovery Habits of Tennis Players.

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

    2018-04-03

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

  12. A biomechanical comparison in the lower limb and lumbar spine between a hit and drag flick in field hockey.

    Ng, Leo; Rosalie, Simon M; Sherry, Dorianne; Loh, Wei Bing; Sjurseth, Andreas M; Iyengar, Shrikant; Wild, Catherine Y

    2018-03-01

    Research has revealed that field hockey drag flickers have greater odds of hip and lumbar injuries compared to non-drag flickers (DF). This study aimed to compare the biomechanics of a field hockey hit and a specialised field hockey drag flick. Eighteen male and seven female specialised hockey DF performed a hit and a drag flick in a motion analysis laboratory with an 18-camera three-dimensional motion analysis system and a calibrated multichannel force platform to examine differences in lower limb and lumbar kinematics and kinetics. Results revealed that drag flicks were performed with more of a forward lunge on the left lower limb resulting in significantly greater left ankle dorsiflexion, knee, hip and lumbar flexion (Pshit. Drag flicks were also performed with significantly greater lateral flexion (P hit. Differences in kinematics lead to greater shear, compression and tensile forces in multiple left lower limb and lumbar joints in the drag flick compared to the hit (P hit may have ramifications with respect to injury in field hockey drag flickers.

  13. MODEL PENGEMBANGAN PERMAINAN FUN HOCKEY PADA SISWA KELAS XI SMA NEGERI 1 BAWANG KECAMATAN BAWANG KABUPATEN BATANG TAHUN 2014.

    Wahyu Putri Vembriana Dewi

    2015-07-01

    Full Text Available The purpose of this study was to produce a model of the development of the game Fun Hockey in the XI student class of SMAN 1 Bawang, Bawang Subdistrict, Batang. The method used is the development of Borg & Gall, namely: (1 to analyze the products that will be developed that are obtained from the information collection, including field observations and study of literature, (2 develop a form of initial product model game Fun Hockey, (3 expert validation test which uses a physical education expert (hockey skills and learning experts physical education in high school, as well as small scale test, using questionnaires and consultations later in the analysis, (4 the first product revision, revision of the product based on the results of expert evaluation and testing of small-scale (12 students, (5 field trials (28 students, (6 the revision of the final product is done based on the results of field trials, (7 the outcome Fun Hockey game for students of XI class generated through the revision of field trials. From the data on the differences can concluded that the Fun Hockey Game model development can be implemented as an alternative model for students learning physical education XI class SMAN 1 Bawang, Bawang Subdistrict, Batang.

  14. Player-Character Dynamics in Multi- Player Role Playing Games

    Tychsen, Anders; McIlwain, D.; Brolund, T.

    2007-01-01

    This paper presents the results of a comprehensive empirical study of the impact of integrating complex game characters in multi-player Role Playing Games across tabletop and digital formats. Players were provided with characters that had detailed background history, personality and goals. Player...

  15. The Player Engagement Process

    Schoenau-Fog, Henrik

    2011-01-01

    , categories and triggers involved in this process. By applying grounded theory to the analysis of the responses, a process-oriented player engagement framework was developed and four main components consisting of objectives, activities, accomplishments and affects as well as the corresponding categories...

  16. Teaching Beginning Trombone Players.

    Fallis, Todd L.

    2001-01-01

    Discusses the process of introducing the trombone to beginning students and addresses the issue of warming-up. Provides resources for beginning trombone methods, band methods, and daily warm-up studies. Includes resources for scale studies and etudes for beginning to intermediate trombone players. (CMK)

  17. Professional-applied physical training students by means of field hockey

    Pylypey L.P.

    2010-01-01

    Full Text Available Description of the modern crisis state of health and physical preparedness of graduating students of higher institutes is resulted. Most graduating students can not high-quality work on a production. Not efficiency of the existent system of physical education is rotined in the institutes of higher. The terms of intensification of educational process are considered. Efficiency and forming actuality is investigational for the students of motivation to the select kind of sport (field hockey. The stages of introduction of innovative approaches, new credit-module technologies in the river-bed of the Bologna system are presented.

  18. Cardiovascular prevention in a high risk sport, ice hockey: applications in wider sports physical therapy practice.

    Hopkins-Rosseel, Diana H

    2006-11-01

    Although acute myocardial infarction and sudden cardiac death are relatively rare occurrences in athletics, cardiovascular accidents do occur. This manuscript presents information on the cardiovascular risks in athletics. In addition, information is provided on screening for cardiovascular risk - including history taking, chart review, physical examination - and the appropriate guidelines on the treatment of athletes found to be at risk. For the purpose of this article, the sport of ice hockey is used to illustrate the subject matter and highlight the behaviors in sport that carry cardiovascular risk. Physical therapists have ethical and legal responsibility to undertake the necessary screening procedures to recognize and respond to any signs of cardiovascular risk in their clients.

  19. The Control of Externalities in Sports Leagues: An Analysis of Restrictions in the National Hockey League

    Dennis W. Carlton; Alan S. Frankel; Elisabeth M. Landes

    2004-01-01

    This paper provides one of the few successful demonstrations of the efficiency of certain types of restrictions in the context of a joint venture. The joint venture we examine is the National Hockey League (NHL) in the 1980s, which was then composed of 21 separately owned teams. (It now has 30 teams.) The restriction we analyze is the NHL rule on franchise relocation. Before one can fully understand the effect of the restriction, one must understand the theory of how sports leagues operate an...

  20. Coste energético del dribling en hockey sobre patines

    Blanco, Dr. Alfonso; Balagué, Dra. Natàlia

    1997-01-01

    El objetivo del presente estudio ha sido analizar y comparar el coste energético del dribling en hockey sobre patines con respecto a la acción de patinar. Doce jugadores amateurs bien entrenados han realizado, durante cinco minutos a 11, 13 y 15 km/h, patinaje solamente y patinaje mientras driblaban la bola con el stick. En ambos casos se evaluaron directamente y compararon consumo de oxígeno, ventilación, frecuencia cardíaca y nivel de percepción subjetiva del esfuerzo. Las variables fisioló...

  1. Diagnosis Aerobic Component of Operational Preparedness Skill Players

    Vasylyuk Vasyl

    2017-01-01

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

  2. The potential risk of personal stereo players

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

    2010-01-01

    The technological development within personal stereo systems,such as MP3 players, e. g. iPods, has changed music listening habits from home entertainment to everyday and everywhere use. The technology has developed considerably, since the introduction of cassette players and CD walkmen. High......-level low-distortion music is produced by minimal devices which can play for long periods. In this paper, the existing literature on effects of personal stereo systems is reviewed, incl. studies of exposure levels, and effects on hearing. Generally, it is found that the levels being used are of concern......, which in one study is demonstrated to relate to the specific use in situations with high levels of background noise. Another study demonstrates that the effect of using personal stereo is comparable to that of being exposed to noise in industry. The results are discussed in view of the measurement...

  3. Practicing field hockey skills along the contextual interference continuum: a comparison of five practice schedules.

    Cheong, Jadeera Phaik Geok; Lay, Brendan; Grove, J Robert; Medic, Nikola; Razman, Rizal

    2012-01-01

    To overcome the weakness of the contextual interference (CI) effect within applied settings, Brady, 2008 recommended that the amount of interference be manipulated. This study investigated the effect of five practice schedules on the learning of three field hockey skills. Fifty-five pre-university students performed a total of 90 trials for each skill under blocked, mixed or random practice orders. Results showed a significant time effect with all five practice conditions leading to improvements in acquisition and learning of the skills. No significant differences were found between the groups. The findings of the present study did not support the CI effect and suggest that either blocked, mixed, or random practice schedules can be used effectively when structuring practice for beginners. Key pointsThe contextual interference effect did not surface when using sport skills.There appears to be no difference between blocked and random practice schedules in the learning of field hockey skills.Low (blocked), moderate (mixed) or high (random) interference practice schedules can be used effectively when conducting a multiple skill practice session for beginners.

  4. Bebop on the Hockey pitch: Cross-disciplinary creativity and skills transfer

    Clive Maxwell Harrison

    2016-02-01

    Full Text Available This paper generalises task-specific (but dissimilar skills, from the jazz concert stage and from the hockey field, into the domain of creativity research. What is sought are clues to what skills or creativities are transferable across dissimilar domains. It is argued that certain domain-general skills are transferable across domains, but a domain-general or ‘c’ creative capacity, is not. Rather than transferring some over-arching capacity to be universally creative, this research highlights factors likely to facilitate successful cross-disciplinary creative expression and posits a correlation between the capacities for discriminant pattern-recognition, task-specific expertise, and sensory data-collection, and the transferability of creativity. Of particular significance is the capacity for informed, selective pattern-breaking based on the ‘depth’ or ‘insider’ perspective of the domain expert; such ‘expert variation and selective retention’ (EVSR provides creative choices and responses that are likely to be perceived by the field as creative: valuable, novel and surprising. The author is a renowned Australian studio bassist, jazz musician, and music educator who also plays field hockey for Australia at Masters level. His recently completed PhD thesis, based on a performance and composition career spanning 46 years, takes the form of an analytical autoethnography drawn from personal field notes, diaries and interviews as well as published record albums.

  5. Campo de hockey Mariñamansa. Orense (España

    García Tolosana, Carlos

    2000-06-01

    Full Text Available This article concerns the construction of a Hockey Court made of artificial green and the building where is located the changing room. The arrangement of the surrounding land and the forecast of the necessary room lo allow the construction of a complementary building where the gymnasium will be located, as well as the Federation headquarters, classrooms, a center lo control drugs and some warehouses, are also foreseen.La actuación de que se trata se concreta en la construcción de un Campo de Hockey de Hierba Artificial y del edificio de vestuarios que lo apoya y complementa. También se contempla la ordenación del entorno próximo y la previsión de espacio para permitir la construcción de un edificio complementario en el que ubicar un gimnasio, los locales de la federación, aulas, un centro de control de dopaje y una dotación de almacenes.

  6. Neck injuries presenting to emergency departments in the United States from 1990 to 1999 for ice hockey, soccer, and American football.

    Delaney, J S; Al-Kashmiri, A

    2005-04-01

    To examine the number and rate of neck injuries in the community as a whole for ice hockey, soccer, and American football by analysing data from patients presenting to emergency departments in the United States from 1990 to 1999. Data compiled for the US Consumer Product Safety Commission were used to generate estimates for the total number of neck injuries and the more specific diagnoses of neck fractures, dislocations, contusions, sprains, strains, and lacerations occurring nationally from 1990 to 1999. These data were combined with yearly participation figures to generate rates of injury presenting to emergency departments for each sport. There were an estimated 5038 neck injuries from ice hockey, 19,341 from soccer, and 114 706 from American football. These could be broken down as follows: 4964 contusions, sprains, or strains from ice hockey, 17,927 from soccer, and 104 483 from football; 105 neck fractures or dislocations from ice hockey, 214 from soccer, and 1588 from football; 199 neck lacerations for ice hockey, 0 for soccer, and 621 for football. The rates for total neck injuries and combined neck contusions, sprains, or strains were higher for football than for ice hockey or soccer in all years for which data were available. The rate of neck injury in the United States was higher in football than in ice hockey or soccer in the time period studied.

  7. Increasing Social Interactions Using Prompts and Rewards for Adolescents with ASD in an Ice Hockey Practice Context

    Beiers, Kevin; Derby, K. Mark; McLaughlin, T. F.

    2016-01-01

    We evaluated the effects of using prompts and reinforcement procedures to increase the social interaction of two children with autism (ASD). This study took place during the context of a hockey practice. Two adolescent participants were evaluated using an ABAB single subject reversal design. Baseline data were collected prior to and after the…

  8. Development and Validation of a Method for Determining Tridimensional Angular Displacements with Special Applications to Ice Hockey Motions.

    Gagnon, Micheline; And Others

    1983-01-01

    A method for determining the tridimensional angular displacement of skates during the two-legged stop in ice hockey was developed and validated. The angles were measured by geometry, using a cinecamera and specially equipped skates. The method provides a new tool for kinetic analyses of skating movements. (Authors/PP)

  9. Active Learning for Player Modeling

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

    2015-01-01

    Learning models of player behavior has been the focus of several studies. This work is motivated by better understanding of player behavior, a knowledge that can ultimately be employed to provide player-adapted or personalized content. In this paper, we propose the use of active learning for player...... experience modeling. We use a dataset from hundreds of players playing Infinite Mario Bros. as a case study and we employ the random forest method to learn mod- els of player experience through the active learning approach. The results obtained suggest that only part of the dataset (up to half the size...... that the method can be used online during the content generation process where the mod- els can improve and better content can be presented as the game is being played....

  10. The Hedonic Haptic Player

    Vallgårda, Anna; Boer, Laurens; Cahill, Ben

    2017-01-01

    In this design case we present the Hedonic Haptic Player—a wearable device that plays different patterns of vibrations on the body as a form of music for the skin. With this we begin to explore the enjoyability of vibrations in a wearable set-up. Instead of implementing vibrations as a haptic...... output for some form of communication we want to explore their hedonistic value. The process leading up to the Hedonic Haptic player served as a first step in getting a grasp of the design space of vibrotactile stimuli in a broader sense. This is reported as seven episodes of explorations. The Hedonic...

  11. Concussion Incidence and Return-to-Play Time in National Basketball Association Players: Results From 2006 to 2014.

    Padaki, Ajay S; Cole, Brian J; Ahmad, Christopher S

    2016-09-01

    Various research efforts have studied concussions in the National Football League, Major League Baseball, and the National Hockey League. However, no study has investigated the incidence and return-to-play trends in the National Basketball Association (NBA), which this study aims to do. Increased media scrutiny and public awareness, in addition to the institution of a league-wide concussion protocol, may have resulted in more conservative return-to-play practices. Descriptive epidemiology study. All concussions to NBA players that were publicly reported in the media from the beginning of the 2006 NBA season to the end of the 2014 season were included. The incidence and return-to-play statistics were generated by synthesizing information from publicly available records. There were 134 publicly reported concussions to NBA players from the beginning of the 2006 season to the conclusion of the 2014 season, resulting in an average of 14.9 concussions per season. The incidence has not changed significantly during this time span. The average games missed after a concussion from 2006 to 2010 was 1.6, significantly less than the 5.0 games missed from 2011 to 2014, following the institution of the NBA concussion protocol (P = .023). Although the incidence of publicly reported concussions in the NBA has not changed appreciably over the past 9 seasons, the time missed after a concussion has. While players often returned in the same game in the 2006 season, the combination of implemented policy, national coverage, medical staff awareness, and player education may have contributed to players now missing an average of 4 to 6 games after a concussion. A multitude of factors has resulted in more conservative return-to-play practices for NBA players after concussions. © 2016 The Author(s).

  12. Neck injuries presenting to emergency departments in the United States from 1990 to 1999 for ice hockey, soccer, and American football

    Delaney, J; Al-Kashmiri, A

    2005-01-01

    Objective: To examine the number and rate of neck injuries in the community as a whole for ice hockey, soccer, and American football by analysing data from patients presenting to emergency departments in the United States from 1990 to 1999.

  13. ANÁLISIS DE LA ACCIÓN DE GOL EN EL PORTERO DE HOCKEY HIERBA

    J. Sampedro

    2010-09-01

    Full Text Available

     

    RESUMEN

    El objetivo fundamental del estudio es analizar el rendimiento del portero de hockey hierba, desde la perspectiva del número de goles encajados en función de la zona de tiro y del lugar por donde entra el lanzamiento. Se analizó una muestra de 278 lanzamientos a portería que acabaron en gol, marcados a 30 porteros/as de nivel internacional de selecciones nacionales absolutas. La técnica de recogida de datos empleada fue la observación sistemática utilizando para ello la base de datos OBANGOHH (Piñeiro, 2006. Los resultados obtenidos determinan que la zona de la tabla, la zona izquierda de la portería, la zona GIT, y el poste largo, son “puntos débiles” del portero/a. Los porteros/as tienen mayores o menores probabilidades de encajar gol dependiendo de la zona del área desde la que tira el delantero y la zona de portería por la que entra el lanzamiento. Además existen diferencias significativas en relación al género del portero. El nivel de significación establecido fue del 95% (p<0,05.
    Palabras Clave: hockey hierba, rendimiento, portero, gol.

     

    ABSTRACT

    The main aim of the study is to analyze the performance of field hockey goalkeeper, from the perspective of the number of goals achieved depending on the zone of shot and of the place where the throwing was goal. 278 shots on goal scored to different goalkeepers of international level of senior national teams were analyzed. According to Piñeiro (2006, the technique of collection of the data used was the systematic observation; using for it the notational data base OBANGOFH. The obtained results determine that the side-boards and back-boards zone, the left zone of the goal, the zone

  14. PRACTICING FIELD HOCKEY SKILLS ALONG THE CONTEXTUAL INTERFERENCE CONTINUUM: A COMPARISON OF FIVE PRACTICE SCHEDULES

    Jadeera Phaik Geok Cheong

    2012-06-01

    Full Text Available To overcome the weakness of the contextual interference (CI effect within applied settings, Brady, 2008 recommended that the amount of interference be manipulated. This study investigated the effect of five practice schedules on the learning of three field hockey skills. Fifty-five pre-university students performed a total of 90 trials for each skill under blocked, mixed or random practice orders. Results showed a significant time effect with all five practice conditions leading to improvements in acquisition and learning of the skills. No significant differences were found between the groups. The findings of the present study did not support the CI effect and suggest that either blocked, mixed, or random practice schedules can be used effectively when structuring practice for beginners

  15. An examination of the cohesion-performance relationship in university hockey teams.

    Slater, M R; Sewell, D F

    1994-10-01

    The objective of this study was to assess, using the Group Environment Questionnaire, whether team cohesion in university-level field hockey was a cause for, or an effect of, successful performance. A quasi-experimental longitudinal design with cross-lagged correlational analysis was adopted and measures of cohesion and performance were taken midway and later in the season. The results of the synchronous correlations showed a positive relationship (with good stationarity) between team cohesion and performance outcome. Although non-significant cross-lagged differentials indicated a circular relationship, the magnitudes of both the cross-lagged correlations and the partial correlations, together with multiple-regression analyses, revealed that the stronger flow was from cohesion to performance. The socially oriented aspects of cohesion, in particular, had significant associations with performance. The results imply that cohesion-performance relationships should be examined within a circular model, in which cohesion and performance are interdependent.

  16. Variables determinantes del drag-flick en jugadoras de hockey hierba

    Cristina López de Subijana Hernández

    2012-12-01

    Full Text Available El penalti córner es una de las situaciones de juego más importantes en el hockey hierba. Las mujeres utilizan menos el drag-flick que los hombres. Los objetivos de este estudio fueron describir los parámetros cinemáticos del drag-flick en jugadoras especialistas y hallar las variables determinantes en el rendimiento en este gesto técnico en jugadoras de hockey. Se analizaron quince lanzamientos de cinco lanzadoras con 6 cámaras del sistema de captura automática VICON registrando a 250 Hz. Para la comparación de medias se utilizó un análisis no paramétrico Kruskall Wallis de un factor (sujeto. Aquellos parámetros en los que se hallaron diferencias significativas, se compararon por pares por medio de una U de Mann Whitney. Las jugadoras 1 (22,5 ± 0,9 m/s y 3 (22,6 ± 0,7 m/s registraron velocidades de salida de la bola superiores (p < 0,001 a todas las demás jugadoras (19,1 ± 0,7 m/s jugadora 2; 20,5 ± 0,4 m/s jugadora 4 y 19,9 ± 0,4 m/s jugadora 5. La jugadora 1 basa su aceleración final en un doble apoyo largo, con una secuencia de velocidades y una distancia recorrida lo más amplia posible. Sin embargo, jugadora 3 basa su velocidad en la carrera previa, y en una secuencia de movimientos explosiva. Las características individuales de cada jugadora juegan un papel importante en la elección de una estrategia técnica u otra de lanzamiento.

  17. Tsunami Hockey

    Weinstein, S.; Becker, N. C.; Wang, D.; Fryer, G. J.

    2013-12-01

    An important issue that vexes tsunami warning centers (TWCs) is when to cancel a tsunami warning once it is in effect. Emergency managers often face a variety of pressures to allow the public to resume their normal activities, but allowing coastal populations to return too quickly can put them at risk. A TWC must, therefore, exercise caution when cancelling a warning. Kim and Whitmore (2013) show that in many cases a TWC can use the decay of tsunami oscillations in a harbor to forecast when its amplitudes will fall to safe levels. This technique should prove reasonably robust for local tsunamis (those that are potentially dangerous within only 100 km of their source region) and for regional tsunamis (whose danger is limited to within 1000km of the source region) as well. For ocean-crossing destructive tsunamis such as the 11 March 2011 Tohoku tsunami, however, this technique may be inadequate. When a tsunami propagates across the ocean basin, it will encounter topographic obstacles such as seamount chains or coastlines, resulting in coherent reflections that can propagate great distances. When these reflections reach previously-impacted coastlines, they can recharge decaying tsunami oscillations and make them hazardous again. Warning center scientists should forecast sea-level records for 24 hours beyond the initial tsunami arrival in order to observe any potential reflections that may pose a hazard. Animations are a convenient way to visualize reflections and gain a broad geographic overview of their impacts. The Pacific Tsunami Warning Center has developed tools based on tsunami simulations using the RIFT tsunami forecast model. RIFT is a linear, parallelized numerical tsunami propagation model that runs very efficiently on a multi-CPU system (Wang et al, 2012). It can simulate 30-hours of tsunami wave propagation in the Pacific Ocean at 4 arc minute resolution in approximately 6 minutes of real time on a 12-CPU system. Constructing a 30-hour animation using 1 minute simulated time steps takes approximately 50 minutes on the same system. These animations are generated quickly enough to provide decision support for emergency managers whose coastlines may be impacted by the tsunami several hours later. Tsunami reflections can also aid in determining the source region for those tsunamis generated by non-seismic mechanisms without a clear source such as meteotsunamis, tsunamis generated by meteorological phenomena. A derecho that crossed the New Jersey coast and entered the Atlantic Ocean at approximately 1500 UTC June 13, 2013 generated a meteotsunami that struck the northeast coast of the US causing several injuries. A DART sensor off Montauk, NY, recorded tsunami waves approximately 200 minutes apart. We show how the arrival times of the tsunamis recorded by this DART can help to constrain the source region of the meteotsunami. We also examine other reflections produced by the Haida Gwaii 2012, Tohoku 2011, and other tsunamis.

  18. Vývoj protokolu o pozorování dovedností pro sledge hokej - pilotní studie Development of a skills observation protocol for sledge ice hockey - pilot study

    Yves Vanlandewijck

    2007-02-01

    Full Text Available V průběhu několika posledních let vzrostly možnosti jedinců s tělesným postiženým zapojit se do fyzických činností. Z tohoto důvodu je uznáván význam zvládnutí sportovních dovedností ještě před samotnou účastí v soutěžích. O stále oblíbenějším sledge hokeji bylo dosud provedeno málo výzkumů. Hlavní složkou výkonu je analýza dovedností. Vzhledem k její uznávané důležitosti a současnému nedostatku příslušných výzkumů na tomto poli jsme při této studii využili videozáznamů z paralympijského sledge hokejového turnaje z Turína v roce 2006, které nám poskytly možnost vytvořit protokol o pozorování s podrobnými kritérii toho, co utváří vyspělé profesionální sledge hokejové dovednosti. Proběhly konzultace s odborníky z tohoto odvětví a jejich zpětná vazba nám umožnila vytvořit tento nástroj. Po dokončení protokolu jsme provedli pilotní vyhodnocení, pro které byli hráči vybíráni na základě statistik z paralympijských her. Tito hráči byli poté pomocí našeho protokolu hodnoceni. Bylo prokázáno, že protokol dokáže úspěšně rozlišovat hráče vyšší a nižší úrovně. Over the past few years opportunities have been increasing for individuals with physical disabilities to become involved in physical activities; hence there is a recognition of the importance of mastering sport skills before participation. Currently there is little research that has been performed on the increasingly popular sport of sledge hockey. A major component of performance is skill analysis. Having recognised its importance and the current unavailability of relevant research in the area, this study used video recordings of the Torino 2006 Paralympic sledge ice hockey tournament to provide a setting in which to produce a skill observation protocol with detailed criteria of what constitutes a mature professional sledge ice hockey skill. Experts in the field were

  19. From Fact to Fiction – An Introduction to the Mythology of Ice Hockey in Canadian Life and Literature

    Jason Blake

    2004-12-01

    Full Text Available The title of Alice Munro’s Who do you think you are? could just as easily be asked of Canada, without eliciting an easy answer. In ethnic, linguistic, even geographical terms, Canada is hardly homogeneous. Because of this, we can only dream of a unified identity; we are, as Leonard Cohen writes in Beautiful Losers, condemned to “nightmares of identity.” If Canada is too complex for a uniform national identity, one derived from a convenient mythology and distilled into simple symbols, it often seems we have yet to realize it. We long for a mythology, even a modern, and blatantly constructed one. In contemporary Canadian society, ice hockey has filled that symbolic role, serving as a mythology that binds a fragmented people. This paper examines the role of ice hockey as a mythologized symbol of Canadian unity in literature, and questions the appropriateness of that usage.

  20. Proprioception of foot and ankle complex in young regular practitioners of ice hockey, ballet dancing and running.

    Li, Jing Xian; Xu, Dong Qing; Hoshizaki, Blaine

    2009-01-01

    This study examined the proprioception of the foot and ankle complex in regular ice hockey practitioners, runners, and ballet dancers. A total of 45 young people with different exercise habits formed four groups: the ice hockey, ballet dancing, running, and sedentary groups. Kinesthesia of the foot and ankle complex was measured in plantarflexion (PF), dorsiflexion (DF), inversion (IV), and eversion (EV) at 0.4 degrees /s using a custom-made device. The results showed the following: (1) significantly better perceived passive motion sense in PF/DF was found as compared with the measurements in IV/EV within each group (P ballet groups perceived significantly better passive motion sense in IV/EV than the running (P ballet dancing on proprioception may be associated with their movement characteristics.

  1. Altitude training considerations for the winter sport athlete.

    Chapman, Robert F; Stickford, Jonathon L; Levine, Benjamin D

    2010-03-01

    Winter sports events routinely take place at low to moderate altitudes, and nearly all Winter Olympic Games have had at least one venue at an altitude >1000 m. The acute and chronic effects of altitude can have a substantial effect on performance outcomes. Acutely, the decline in oxygen delivery to working muscle decreases maximal oxygen uptake, negatively affecting performance in endurance events, such as cross-country skiing and biathlon. The reduction in air resistance at altitude can dramatically affect sports involving high velocities and technical skill components, such as ski jumping, speed skating, figure skating and ice hockey. Dissociation between velocity and sensations usually associated with work intensity (ventilation, metabolic signals in skeletal muscle and heart rate) may impair pacing strategy and make it difficult to determine optimal race pace. For competitions taking place at altitude, a number of strategies may be useful, depending on the altitude of residence of the athlete and ultimate competition altitude, as follows. First, allow extra time and practice (how much is yet undetermined) for athletes to adjust to the changes in projectile motion; hockey, shooting, figure skating and ski jumping may be particularly affected. These considerations apply equally in the reverse direction; that is, for athletes practising at altitude but competing at sea level. Second, allow time for acclimatization for endurance sports: 3-5 days if possible, especially for low altitude (500-2000 m); 1-2 weeks for moderate altitude (2000-3000 m); and at least 2 weeks if possible for high altitude (>3000 m). Third, increase exercise-recovery ratios as much as possible, with 1:3 ratio probably optimal, and consider more frequent substitutions for sports where this is allowed, such as ice hockey. Fourth, consider the use of supplemental O(2) on the sideline (ice hockey) or in between heats (skating and Alpine skiing) to facilitate recovery. For competitions at sea

  2. Mechanical alterations during interval-training treadmill runs in high-level male team-sport players.

    Girard, Olivier; Brocherie, Franck; Morin, Jean-Benoit; Millet, Grégoire P

    2017-01-01

    To examine mechanical alterations during interval-training treadmill runs in high-level team-sport players. Within-participants repeated measures. Twenty high-level male field-hockey players performed six 30-s runs at 5.53±0.19ms -1 corresponding to 115% of their velocity associated with maximal oxygen uptake (vVO 2max ) with 30-s passive recovery on an instrumented treadmill. Continuous measurement of running kinetics/kinematics and spring-mass characteristics were performed and values were subsequently averaged over 20s (8th-28ths) for comparison. Contact time (+1.1±4.3%; p=0.044), aerial time (+4.1±5.3%; p=0.001), step length (+2.4±2.2%; pteam-sport players modified their mechanical behaviour towards lower vertical stiffness while preserving a constant leg stiffness. Maintenance of running velocity induced longer step lengths and decreased step frequencies that were also accompanied by increased impact loading rates. These mechanical alterations occurred early during the set. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  3. MASCULINITY AND SPORT REVISTED: A REVIEW OF LITERATURE ON HEGEMONIC MASCULINITY AND MEN'S ICE HOCKEY IN CANADA

    Cheryl A. MacDonald

    2014-01-01

    Ice hockey is particularly significant in Canada as it acts as a primary site of socialization for boys and men. This form of socialization raises questions about masculinity on the public agenda in terms of the problematic nature of hypermasculinity in sport, stereotypical images of athletes, and questions of social responsibility as both men and athletes. These issues are presently relevant as Canada (and perhaps all of North America) finds itself in an era characterized by accounts in main...

  4. The Astro Learning Design Player

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

    2010-01-01

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

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

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

    2016-01-01

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

  6. A COMPARISON OF THE ANTHROPOMETRIC PARAMETERS BETWEEN BASKETBALL PLAYERS, HANDBALL PLAYERS AND VOLLEYBALL PLAYERS

    Florian Miftari; Juel Jarani; Dhimitraq Stratoberdha; Hazir Salihu

    2017-01-01

    The purpose of this study was to compare the anthropometric measurement to the professional players of the three different disciplines of basketball, handball and volleyball. . For each player anthropometric measurements such as weight, body height, waist circumference, BMI and skinfold calculation on different sports are performed. Differences in terms of anthropometric measurements were assessed by independent static tests and the differences for each variable for each sport were evaluated ...

  7. Frontal Lobe Function in Chess Players

    Vahid Nejati

    2012-05-01

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

  8. Frontal lobe function in chess players.

    Nejati, Majid; Nejati, Vahid

    2012-01-01

    Chess is considered as a cognitive game because of severe engagement of the mental resources during playing. The purpose of this study is evaluation of frontal lobe function of chess players with matched non-players. Wisconsin Card Sorting Test (WCST) data showed no difference between the player and non-player groups in preservation error and completed categories but surprisingly showed significantly lower grade of the player group in correct response. Our data reveal that chess players don't have any preference in any stage of Stroop test. Chess players don't have any preference in selective attention, inhibition and executive cognitive function. Chess players' have lower shifting abilities than non-players.

  9. Time course and dimensions of postural control changes following neuromuscular training in youth field hockey athletes.

    Zech, Astrid; Klahn, Philipp; Hoeft, Jon; zu Eulenburg, Christine; Steib, Simon

    2014-02-01

    Injury prevention effects of neuromuscular training have been partly attributed to postural control adaptations. Uncertainty exists regarding the magnitude of these adaptations and on how they can be adequately monitored. The objective was to determine the time course of neuromuscular training effects on functional, dynamic and static balance measures. Thirty youth (14.9 ± 3 years) field hockey athletes were randomised to an intervention or control group. The intervention included a 20-min neuromuscular warm-up program performed twice weekly for 10 weeks. Balance assessments were performed at baseline, week three, week six and post-intervention. They included the star excursion balance test (SEBT), balance error scoring system (BESS), jump-landing time to stabilization (TTS) and center of pressure (COP) sway velocity during single-leg standing. No baseline differences were found between groups in demographic data and balance measures. Adherence was at 86%. All balance measures except the medial-lateral TTS improved significantly over time (p controls (31.8 ± 22.1%). There were no significant group by time interactions in the SEBT, TTS and COP sway velocity. Neuromuscular training was effective in improving postural control in youth team athletes. However, this effect was not reflected in all balance measures suggesting that the neuromuscular training did not influence all dimensions of postural control. Further studies are needed to confirm the potential of specific warm-up programs to improve postural control.

  10. Why do sleeping nematodes adopt a hockey-stick-like posture?

    Nora Tramm

    Full Text Available A characteristic posture is considered one of the behavioral hallmarks of sleep, and typically includes functional features such as support for the limbs and shielding of sensory organs. The nematode C. elegans exhibits a sleep-like state during a stage termed lethargus, which precedes ecdysis at the transition between larval stages. A hockey-stick-like posture is commonly observed during lethargus. What might its function be? It was previously noted that during lethargus, C. elegans nematodes abruptly rotate about their longitudinal axis. Plausibly, these "flips" facilitate ecdysis by assisting the disassociation of the old cuticle from the new one. We found that body-posture during lethargus was established using a stereotypical motor program and that body bends during lethargus quiescence were actively maintained. Moreover, flips occurred almost exclusively when the animals exhibited a single body bend, preferentially in the anterior or mid section of the body. We describe a simple biomechanical model that imposes the observed lengths of the longitudinally directed body-wall muscles on an otherwise passive elastic rod. We show that this minimal model is sufficient for generating a rotation about the anterior-posterior body axis. Our analysis suggests that posture during lethargus quiescence may serve a developmental role in facilitating flips and that the control of body wall muscles in anterior and posterior body regions are distinct.

  11. Physical fitness of elite Belgian soccer players by player position.

    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.

  12. Secure Multi-Player Protocols

    Fehr, Serge

    While classically cryptography is concerned with the problem of private communication among two entities, say players, in modern cryptography multi-player protocols play an important role. And among these, it is probably fair to say that secret sharing, and its stronger version verifiable secret...... sharing (VSS), as well as multi-party computation (MPC) belong to the most appealing and/or useful ones. The former two are basic tools to achieve better robustness of cryptographic schemes against malfunction or misuse by “decentralizing” the security from one single to a whole group of individuals...... (captured by the term threshold cryptography). The latter allows—at least in principle—to execute any collaboration among a group of players in a secure way that guarantees the correctness of the outcome but simultaneously respects the privacy of the participants. In this work, we study three aspects...

  13. Linear Quadratic Controller with Fault Detection in Compact Disk Players

    Vidal, Enrique Sanchez; Hansen, K.G.; Andersen, R.S.

    2001-01-01

    The design of the positioning controllers in Optical Disk Drives are today subjected to a trade off between an acceptable suppression of external disturbances and an acceptable immunity against surfaces defects. In this paper an algorithm is suggested to detect defects of the disk surface combined...... with an observer and a Linear Quadratic Regulator. As a result, the mentioned trade off is minimized and the playability of the tested compact disk player is considerably enhanced....

  14. Relationship between body composition, leg strength, anaerobic power, and on-ice skating performance in division I men's hockey athletes.

    Potteiger, Jeffrey A; Smith, Dean L; Maier, Mark L; Foster, Timothy S

    2010-07-01

    The purpose of this study was to examine relationships between laboratory tests and on-ice skating performance in division I men's hockey athletes. Twenty-one men (age 20.7 +/- 1.6 years) were assessed for body composition, isokinetic force production in the quadriceps and hamstring muscles, and anaerobic muscle power via the Wingate 30-second cycle ergometer test. Air displacement plethysmography was used to determine % body fat (%FAT), fat-free mass (FFM), and fat mass. Peak torque and total work during 10 maximal effort repetitions at 120 degrees .s were measured during concentric muscle actions using an isokinetic dynamometer. Muscle power was measured using a Monark cycle ergometer with resistance set at 7.5% of body mass. On-ice skating performance was measured during 6 timed 89-m sprints with subjects wearing full hockey equipment. First length skate (FLS) was 54 m, and total length skate (TLS) was 89 m with fastest and average skating times used in the analysis. Correlation coefficients were used to determine relationships between laboratory testing and on-ice performance. Subjects had a body mass of 88.8 +/- 7.8 kg and %FAT of 11.9 +/- 4.6. First length skate-Average and TLS-Average skating times were moderately correlated to %FAT ([r = 0.53; p = 0.013] and [r = 0.57; p = 0.007]) such that a greater %FAT was related to slower skating speeds. First length skate-Fastest was correlated to Wingate percent fatigue index (r = -0.48; p = 0.027) and FLS-Average was correlated to Wingate peak power per kilogram body mass (r = -0.43; p = 0.05). Laboratory testing of select variables can predict skating performance in ice hockey athletes. This information can be used to develop targeted and effective strength and conditioning programs that will improve on-ice skating speed.

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

    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…

  16. The modified inverse hockey stick technique for adjuvant irradiation after mastectomy

    Kukolowicz, P.; Selerski, B.; Kuszewski, T.; Wieczorek, A.

    2004-01-01

    To present the technique of irradiation of post-mastectomy patients used in the Holycross Cancer Centre in Kielce.The paper presents a detailed description of the technique which is referred to as the 'modified inverse hockey stick technique (MIHS)'. The dosimetric characteristic of dose distribution for the MIHS technique is presented basing on dose distributions calculated for 40 patients. The measurements used to evaluate dose distribution included standard deviation of the dose in the Planning Target Volume (PTV) and the percentage of the PTV volume receiving a dose larger than 110% and smaller than 90%; the lung volume received at least 20 Gy (LV20) and the heart volume received at least 30 Gy (HV30). The distribution of the electron beam energy is also presented. The standard deviation of the dose in the PTV was approx. 10% in a majority of patients. About 12% of the PTV volume received a dose more than 10% smaller than intended and about 10% of the PTV volume received a dose more than 10% greater than intended. For patients irradiated on the left side of the chest wall the LV20 was always lesser than 25% and for patients irradiated on the right side of the chest wall - always less than 35%, except for one patient, in whom it reached 37%. The HV30 was always below 8%. The MIHS technique is a safe and reliable modality. The main advantages of the technique include very convenient and easily repeated positioning of the patient and small doses applied to the organs at risk. The individually calculated bolus plays an important role in diminishing the dose to the lung and heart. The disadvantages of the technique include poor dose homogeneity within the PTV and long matching lines of the electron and photon beams. (author)

  17. Sophisticated Players and Sophisticated Agents

    Rustichini, A.

    1998-01-01

    A sophisticated player is an individual who takes the action of the opponents, in a strategic situation, as determined by decision of rational opponents, and acts accordingly. A sophisticated agent is rational in the choice of his action, but ignores the fact that he is part of a strategic

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

    Kelly M. Hastings

    2015-03-01

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

  19. Establishing the Test-Retest Reliability & Concurrent Validity for the Repeat Ice Skating Test (RIST) in Adolescent Male Ice Hockey Players

    Power, Allan; Faught, Brent E.; Przysucha, Eryk; McPherson, Moira; Montelpare, William

    2012-01-01

    In this study the authors examine the test-retest reliability and concurrent validity of the Repeat Ice Skating Test (RIST). This was an on-ice field anaerobic test that measured average peak power and was validated with 3 anaerobic lab tests: (a) vertical jump, (b) the Margaria-Kalamen stair test, and (c) the Wingate Anaerobic Test. The…

  20. Multiple player tracking in sports video: a dual-mode two-way bayesian inference approach with progressive observation modeling.

    Xing, Junliang; Ai, Haizhou; Liu, Liwei; Lao, Shihong

    2011-06-01

    Multiple object tracking (MOT) is a very challenging task yet of fundamental importance for many practical applications. In this paper, we focus on the problem of tracking multiple players in sports video which is even more difficult due to the abrupt movements of players and their complex interactions. To handle the difficulties in this problem, we present a new MOT algorithm which contributes both in the observation modeling level and in the tracking strategy level. For the observation modeling, we develop a progressive observation modeling process that is able to provide strong tracking observations and greatly facilitate the tracking task. For the tracking strategy, we propose a dual-mode two-way Bayesian inference approach which dynamically switches between an offline general model and an online dedicated model to deal with single isolated object tracking and multiple occluded object tracking integrally by forward filtering and backward smoothing. Extensive experiments on different kinds of sports videos, including football, basketball, as well as hockey, demonstrate the effectiveness and efficiency of the proposed method.

  1. Adapting playware to multiple players

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

    2011-01-01

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

  2. Spondylolysis in young tennis players

    Ruiz‐Cotorro, A; Balius‐Matas, R; Estruch‐Massana, A; Angulo, J Vilaró

    2006-01-01

    The general aetiology, diagnosis, and treatment of spondylolysis, a bone defect in the pars interarticularis of the vertebra, are reviewed. A retrospective study of young tennis players diagnosed between 2000 and 2004 with spondylolysis with or without spondylolisthesis, assessed by radiography and planar bone scintigraphy, is described. If the radiographic results were negative, computed tomography was performed. Sixty six cases were evaluated: 53 L5 lesions, eight L4 lesions, two L3 lesions, and one bilateral lesion at the L2 level. Two more lesions at two levels were found (bilateral L5 and unilateral L4 and L3 on the right side). Classification, treatment, and outcome of the cases are reported. A combination of radiography, planar bone scintigraphy, and SPECT is useful for evaluating spondylolysis in tennis players and recommending treatment. Use of a brace did not appear to achieve significant results. PMID:16632576

  3. Game Cinematography: from Camera Control to Player Emotions

    Burelli, Paolo

    2016-01-01

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

  4. Cardiovascular changes in video-game players. Cause for concern?

    Gwinup, G; Haw, T; Elias, A

    1983-12-01

    Video games are one of the most popular recreational activities among Americans of all ages, especially teenaged boys and young men. Studies of the health hazards of video-game playing have linked seizures, psychologic disturbances, and other health problems with the games. The study reported here measured changes in blood pressure and heart rate that occurred in 23 young men when they played a video game. The mean systolic blood pressure for the entire group was considerably higher during play than before or after and was significantly higher in novice players than in more skilled players. Heart rate was also significantly higher during play. In view of these results, other cardiovascular changes might be expected to occur during video-game playing. Although the changes reported here were minor, even minor cardiovascular alterations could potentially prove serious in persons with cardiovascular disease.

  5. Untypical Undergraduate Research: Player Motion Analysis in Sports

    Loerke, Dinah

    There is significant concern about the degree of attrition in STEM disciplines from the start of K-12 through to the end of higher education, and the analysis of the `leaky pipeline' from the various institutions has identified a critical decline - which may be as high as 60 percent - between the fraction of students who identify as having an interest in a science or engineering major at the start of college/university, and the fraction of students who ultimately graduate with a STEM degree. It has been shown that this decline is even more dramatic for women and underrepresented minorities (Blickenstaff 2005, Metcalf 2010). One intervention which has been proven to be effective for retention of potential STEM students is early research experience, particularly if it facilitates the students' integration into a STEM learning community (Graham et al. 2013, Toven-Lindsey et al. 2015). In other words, to retain students in STEM majors, we would like to encourage them to `think of themselves as scientists', and simultaneously promote supportive peer networks. The University of Denver (DU) already has a strong undergraduate research program. However, while the current program provides valuable training for many students, it likely comes too late to be effective for student retention in STEM, because it primarily serves older students who have already finished the basic coursework in their discipline; within physics, we know that the introductory physics courses already serve as gatekeeper courses that cause many gifted but `non-typical' students to lose interest in pursuing a STEM major (Tobias 1990). To address this issue, my lab is developing a small research spinoff program in which we apply spatiotemporal motion analysis to the motion trajectories of players in sports, using video recordings of DU Pioneer hockey games. This project aims to fulfill a dual purpose: The research is framed in a way that we think is attractive and accessible for beginning students who

  6. Motivational profile quality players handball

    Alfonso Martínez Moreno

    2017-06-01

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

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

    Szczepańska, Elzbieta; Spałkowska, Agnieszka

    2012-01-01

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

  8. Relative Age Effect in Swedish Male and Female Tennis Players Born in 1998–2001

    Göran Gerdin

    2018-04-01

    Full Text Available The relative age effect (RAE has been extensively debated and researched in both popular media and academic discourse. This study examined RAE in Swedish tennis players born in 1998–2001. The study was conducted in 2015–2016 and includes all ranked Swedish tennis players (n = 1835 registered in the Swedish Tennis Association database from the year 2014. The results show that when the birth dates of the corresponding Swedish population and all the ranked players are compared, they show a moderate RAE; however, the higher up they are in the ranking system, the greater the RAE becomes. Top 10 players display an average of 64.1% being born in the first half of the year. Some gender differences were also found, with a greater proportion of both higher and lower ranked females being born in the first half of the year. In our discussion of the findings we raise several issues that need to be addressed to provide more equal opportunities for all junior players regardless of birth date. Resolving ongoing problems associated with RAE in competitive sports such as tennis is important both in term of prolonged participation in the sport and increased performance. Suggestions made in this article include recognising RAE when designing the format of competitions/tournaments, not using official rankings until the juniors get older, addressing RAE in a “gender sensitive” way, and conducting further in-depth studies in which RAE is understood/examined as being associated with environmental factors. Although these findings show the RAE effect in Swedish tennis players, thus pointing at the need for further consideration in terms of ranking and selection procedures to ensure equal opportunities for player development, the study also concludes by reasserting an emphasis on a holistic approach to player development in which coaches focus on the developmentally appropriate needs and potential of each individual player regardless of their biological age.

  9. Vitamin D Deficiency Among Professional Basketball Players.

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

    2016-07-01

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

  10. "Let's Pick Him!" : Ratings of Skill Level on the Basis of In-Game Playing Behaviour in Bantam League Junior Ice Hockey

    Tromp, E. J. Yvonne; Pepping, Gert-Jan; Lyons, Jim; Elferink-Gemser, Marije T.; Visscher, Chris

    2013-01-01

    Rating a player's skill level is an essential task for coaches to select the players with greatest potential to reach the top and to further be able to adjust the training program to the skill level of the player in order to most optimally facilitate the player's learning and performance. However,

  11. Juego, Cultura y Desarrollo en la Infancia: El caso del Palín Mapuche y el Hockey. Play, Culture and Development in Childhood: Analysis of Mapuche’s Palin and Hockey.

    Garoz , Ignacio

    2006-01-01

    Full Text Available ResumenEl propósito del presente trabajo consiste en analizar los juegos de reglas, partiendo de su papel como transmisores de conocimiento sobre el mundo social (valores, creencias, normas, roles, etc., a partir del planteamiento piagetiano de la comprensión de las reglas de los juegos por los niños. Se aborda cómo se produce la evolución del conocimiento práctico y teórico de las reglas y se incorpora el estudio sobre el desarrollo del conocimiento del significado de los juegos, de sus reglas y acciones. Se utiliza un enfoque transcultural que nos permita comprender las diferencias entre el desarrollo de la regla a través de un juego deportivo como el hockey hierba en España y un juego tradicional del pueblo indígena mapuche de Chile, el palín o chueca.AbstractThe aim of this work is to analyse rule games and their importance in conveying understanding of the social world (values, beliefs, norms, roles, etc., following the Piagetian explanation of how children understand the rules of the games. Starting with the development of practical and theoretical grasp of rules the study includes children's understanding of meaning of games, their rules and play actions. A crosscultural comparison is used to explore the differences between how an understanding of rule is developed in a sporting game such as grass hockey in Spain and in a traditional game of the Mapuche indigenous tribe of Chile, such as palin (or chueca.

  12. Inicios del Hockey patines en Sevilla. El Patín Claret en la década de los 70 del siglo XX = Beginnings of Roller Hockey in Seville. Claret Skate in the Decade of the Twenthieh Century 70

    Jaime Segundo Cuesta Pérez

    2013-10-01

    Full Text Available En el siguiente artículo, se trata de presentar una de las páginas más importantes de la historia del Hockey Patines en Andalucía y más concretamente en la ciudad de Sevilla. Un deporte prácticamente copado desde sus inicios por equipos catalanes y cuya implantación en el resto del país ha sido muy complicada, siendo aún hoy en día muy escasa por toda España, salvo en regiones muy localizadas como Cataluña, Madrid, o Galicia. Estos que ahora presentamos son parte de los orígenes de este deporte en la capital andaluza, de los cuales nacería, para sorpresa de muchos, un equipo que alcanzaría importantes hitos en la División de Honor Nacional de este deporte.---------------------------------------------------------------------In the next article, we try to present one of the most important papers of the roller hockey history in Andalucía, concretely in Seville. This sport has been surrounded from its beginning by teams from Cataluña, while the establishment in the rest of the country has been very difficult, being still today quite scarce all over Spain, except in some regions such as Cataluña, Madrid or Galicia. We will try to show you the origin of this sport in the capital of Andalucía, from where was born, surprising everybody, a team wich achieved great landmark in the Pride National Division of this sport.

  13. The Prevalence of Injuries in Professional Turkish Soccer Players

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

    2011-01-01

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

  14. Auditory memory function in expert chess players.

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

    2015-01-01

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

  15. Chess players' fame versus their merit.

    Simkin, M V; Roychowdhury, V P

    2015-12-12

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

  16. Chaotic dynamics in nonlinear duopoly Stackelberg game with heterogeneous players

    Xiao, Yue; Peng, Yu; Lu, Qian; Wu, Xue

    2018-02-01

    In this paper, a nonlinear duopoly Stackelberg game of competition on output is concerned. In consideration of the effects of difference between plan products and actual products, the two heterogeneous players always adopt suitable strategies which can improve their benefits most. In general, status of each firm is unequal. As the firms take strategies sequentially and produce simultaneously, complex behaviors are brought about. Numerical simulation presents period doubling bifurcation, maximal Lyapunov exponent and chaos. Moreover, an appropriate method of chaos controlling is applied and fractal dimension is analyzed as well.

  17. Cooperation: New Players in Africa

    Philippe Hugon

    2010-03-01

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

  18. Assessment of Specificity of the Badcamp Agility Test for Badminton Players

    de França Bahia Loureiro Luiz

    2017-06-01

    Full Text Available The Badcamp agility test was created to evaluate agility of badminton players. The Badcamp is a valid and reliable test, however, a doubt about the need for the use of this test exists as simpler tests could provide similar information about agility in badminton players. Thus, the aim of this study was to examine the specificity of the Badcamp, comparing the performance of badminton players and athletes from other sports in the Badcamp and the shuttle run agility test (SRAT. Sixty-four young male and female athletes aged between 14 and 16 years participated in the study. They were divided into 4 groups of 16 according to their sport practices: badminton, tennis, team sport (basketball and volleyball, and track and field. We compared the groups in both tests, the Badcamp and SRAT. The results revealed that the group of badminton players was faster compared to all other groups in the Badcamp. However, in the SRAT there were no differences among groups composed of athletes from open skill sports (e.g., badminton, tennis, and team sports, and a considerable reduction of the difference between badminton players and track and field athletes. Thus, we concluded that the Badcamp test is a specific agility test for badminton players and should be considered in evaluating athletes of this sport modality.

  19. Assessment of Specificity of the Badcamp Agility test for Badminton Players.

    de França Bahia Loureiro, Luiz; Costa Dias, Mário Oliveira; Cremasco, Felipe Couto; da Silva, Maicon Guimarães; de Freitas, Paulo Barbosa

    2017-06-01

    The Badcamp agility test was created to evaluate agility of badminton players. The Badcamp is a valid and reliable test, however, a doubt about the need for the use of this test exists as simpler tests could provide similar information about agility in badminton players. Thus, the aim of this study was to examine the specificity of the Badcamp, comparing the performance of badminton players and athletes from other sports in the Badcamp and the shuttle run agility test (SRAT). Sixty-four young male and female athletes aged between 14 and 16 years participated in the study. They were divided into 4 groups of 16 according to their sport practices: badminton, tennis, team sport (basketball and volleyball), and track and field. We compared the groups in both tests, the Badcamp and SRAT. The results revealed that the group of badminton players was faster compared to all other groups in the Badcamp. However, in the SRAT there were no differences among groups composed of athletes from open skill sports (e.g., badminton, tennis, and team sports), and a considerable reduction of the difference between badminton players and track and field athletes. Thus, we concluded that the Badcamp test is a specific agility test for badminton players and should be considered in evaluating athletes of this sport modality.

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

    Vanessa Martínez-Lagunas

    2014-12-01

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

  1. Computing Decoupled Residuals for Compact Disc Players

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

    2006-01-01

    a pair of residuals generated by Compact Disc Player. However, these residuals depend on the performance of position servos in the Compact Disc Player. In other publications of the same authors a pair of decoupled residuals is derived. However, the computation of these alternative residuals has been...

  2. Fault Predictive Control of Compact Disk Players

    Odgaard, Peter Fogh; Wickerhauser, Mladen Victor

    2006-01-01

    Optical disc players such as CD-players have problems playing certain discs with surface faults like scratches and fingerprints. The problem is to be found in the servo controller which positions the optical pick-up, such that the laser beam is focused on the information track. A scheme handling...

  3. Player behavioural modelling for video games

    van Lankveld, G.; Spronck, P.H.M.; Bakkes, S.C.J.

    2012-01-01

    Player behavioural modelling has grown from a means to improve the playing strength of computer programs that play classic games (e.g., chess), to a means for impacting the player experience and satisfaction in video games, as well as in cross-domain applications such as interactive storytelling. In

  4. Outcomes of microfracture in professional basketball players.

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

    2009-09-01

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

  5. An embouchure aid for saxophone player

    Ho-Jin Moon

    2012-02-01

    Full Text Available This study aims to introduce the method that can relieve vibrating forces to oral environment by making an embouchure aid. Thin plastic crown forms were fabricated to prevent tooth abrasion and irritation to lip mucosa for the saxophone player. After application to the player, the most comfort form was chosen and delivered to 3 professional saxophone players. After 5 mon, the players responded to the survey. This embouchure aid did not disturb playing and gave comfort to lower lip. In general, the players preferred thin soft type and thought it caused little effect on sound. Far too little attention has been paid to the problems encountered by single-reed wind instrumentalist who suffer from tooth abrasion and irritation to lip mucosa. The embouchure aid not only prevent tooth damage but also diminish the discomfort of tight embouchure.

  6. Surrounding information consideration promotes cooperation in Prisoner’s dilemma game

    Shu, Gang; Du, Xia; Li, Ya

    2016-01-01

    Highlights: • A new method of strategy updating is proposed in the Prisoner’s dilemma game. • The stochastic players only consider their neighbor’s payoff and update strategy by classical Fermi rule. • The advanced player would consider not only the neighbor’s payoff but also the neighbors’ local surrounding information. • The simulation result illustrates that with the increase of advanced players in the network, the fraction of cooperation increases. - Abstract: Evolutionary game theory provides a useful, integrative framework for studying the evolution of cooperation. A new strategy updating method is proposed in our model. Due to people with diversified thinking, players are divided into two categories based on their different strategy updating method: ordinary players and advanced players. The former players only consider their neighbor’s payoff and updating strategy by classical Fermi rule, while the latter players take both the neighbors’ surrounding information and payoff into account. The results show that the neighbors surrounding information consideration contributes to the evolution of cooperation and finds the fraction of cooperation grows evidently with the increase of advanced players numbers. Our model may provide a pragmatic approach to the research of cooperation in social network.

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

    Li, Lichun; Feron, Eric; Shamma, Jeff S.

    2017-01-01

    the opponents' corresponding best responses depends only on the informed player's history action sequences. Moreover, efficient LP formulations to compute both player's security strategies are provided.

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

    Li, Lichun

    2017-01-05

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

  9. Executive Functioning in Highly Talented Soccer Players

    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

  10. Executive functioning in highly talented soccer players.

    Lot Verburgh

    Full Text Available 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.

  11. Female adolescent elite handball players are more susceptible to shoulder problems than their male counterparts.

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

    2018-02-10

    Shoulder problems are frequent among senior elite handball players. The objective of this study was to assess the prevalence of shoulder problems among adolescent elite handball players and to investigate potential differences in gender, school grade, playing position and playing level. During the 2014 and 2015 pre-season periods, 471 players (age 15-18 years, 54% female) completed a comprehensive baseline questionnaire regarding history of any shoulder pain and shoulder problems experienced during the past season. The players were monitored weekly for one competition season (September-April) regarding shoulder problems and the amount of match and training. Generalised linear models with a binomial link function were used to calculate a prevalence ratio (PR) with 95% confidence interval (CI) to compare the subgroups of players. In total, 110 players (23%) reported having substantial shoulder problems (defined as moderate/severe reduction in training volume, or moderate/severe reduction in performance, or complete inability to participate) at some point during the follow-up season, of which almost half reported complete inability to participate. Of those players reporting substantial problems, 43% (95% CI 39-48) did so for at least 3 consecutive weeks during the season. The prevalence was significantly higher in female players (PR 1.46, 95% 1.04-2.06) and in backcourt players (PR 1.58, 95% CI 1.08-2.32), but no differences were found for school grade (PR 1.21 95% CI 0.88-1.67) or playing level (PR 1.09 95% CI 0.76-1.56). The prevalence of substantial shoulder problems in adolescent elite handball players is high, especially among females, and this warrants further studies on risk factors for shoulder injury and the development of prevention strategies in handball players already before the age of 15. These findings also highlight the importance of introducing a clinical monitoring programme on a routine basis and improving the medical support, taking gender

  12. Public participation: Picking the players

    McNeill, L.; Jernigan, G.

    1995-01-01

    When citizens become involved in the public policy decision-making process, who picks the players? Are there any criteria for determining which members of the public should sit at the table? These are questions frequently asked by new participants and observers of the public involvement process. In the interest of trust and credibility, the process must be one of self-selection. Any exclusion on the part of the sponsoring organization would probably be interpreted by the public and the press as manipulative self-interest. Clearly, at times there are irrational people attending public meetings or submitting written comments. But if an organization begins excluding participants, the risk increases that the process will be perceived as a travesty

  13. A Change in Team Culture Towards an Autonomy Supportive Working Environment - A Case Study of the Finnish Women’s National Ice Hockey Team

    Andler, Martin

    2017-01-01

    This study presents how the change in team culture has impacted the Finnish Women’s National Ice Hockey Team. The structure of the study is based on the self-determination theory, autonomy supportive coaching and change in team culture. The sub chapters’ focus on motivation, the coaches' and athletes' role within the autonomy supportive team working environment, autonomous goal setting and transformational leadership. The subchapter for cultural change is focused on the complex on-going proce...

  14. Incidence of Stingers in Young Rugby Players.

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

    2015-11-01

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

  15. Three-dimensional kinematics of the knee and ankle joints for three consecutive push-offs during ice hockey skating starts.

    Lafontaine, Dany

    2007-09-01

    Little biomechanical research has been conducted recently on hockey skating despite the sport's worldwide appeal. One reason for this lack of biomechanical knowledge stems from the difficulty of collecting data. The lack of accuracy, the disputable realism of treadmills, and the large field of view required are some of the technical challenges that have to be overcome. The main objective of the current study was to improve our knowledge of the joint kinematics during the skating stroke. A second objective was to improve the data collection system we developed and the third was to establish if a kinematic progression exists in the hockey skating stroke similar to that in speed skating. Relative motions at the knee and ankle joints were computed using a joint coordinate system approach. The differences at the knee joints in push-offs indicated that the skating skill was progressively changing with each push-off. The relative stability of the ankle angles can be attributed to the design of the skate boots, which have recently become very rigid. Further research on ice hockey skating is warranted and should include more skaters and investigate the effect various starting strategies and variations in equipment have on skaters' performance.

  16. Protective equipment use among female rugby players.

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

    2005-07-01

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

  17. Musculoskeletal injuries among Malaysian badminton players.

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

    2009-11-01

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

  18. Towards Player-Driven Procedural Content Generation

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

    2012-01-01

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

  19. Validation of the FASH (Functional Assessment Scale for Acute Hamstring Injuries) questionnaire for German-speaking football players.

    Lohrer, Heinz; Nauck, Tanja; Korakakis, Vasileios; Malliaropoulos, Nikos

    2016-10-24

    The FASH (Functional Assessment Scale for Acute Hamstring Injuries) questionnaire has been recently developed as a disease-specific self-administered questionnaire for use in Greek, English, and German languages. Its psychometric qualities (validity and reliability) were tested only in Greek-speaking patients mainly representing track and field athletes. As hamstring injuries represent the most common football injury, we tested the validity and reliability of the FASH-G (G = German version) questionnaire in German-speaking footballers suffering from acute hamstring injuries. The FASH-G questionnaire was tested for reliability and validity, in 16 footballers with hamstring injuries (patients' group), 77 asymptomatic footballers (healthy group), and 19 field hockey players (at-risk group). Known-group validity was tested by comparing the total FASH-G scores of the injured and non-injured groups. Reliability of the FASH-G questionnaire was analysed in 18 asymptomatic footballers using the intra-class coefficient. Known-group validity was demonstrated by significant differences between injured and non-injured participants (p hamstring injuries in German footballers.

  20. The Anthropometric Characteristics of Futsal Players Compared with Professional Soccer Players

    Burdukiewicz Anna

    2014-08-01

    Full Text Available Purpose. The aim of the study was to compare the morphological characteristics of experienced futsal players with professional soccer players. Methods. The research sample included 22 university futsal players and 22 professional soccer players. Parameters including body height and mass, skinfold thicknesses of the trunk and extremities, lower limb length, trunk width, humerus and femur bone breadths, and the circumferences of the chest, hips, thighs, and calves were used to calculate various somatic indices. Somatotyping was performed using the Heath–carter method. Differences in the characteristics between the futsal and soccer players were analyzed using Student’s t test. Intragroup analysis was also performed on futsal players depending on player position and compared with the arithmetic means and standard deviations of all variables of the entire sample. Results. compared with their soccer-playing peers, the futsal players were shorter, weighed less, had shorter lower limbs, narrower hips, and smaller hip circumference and bone breadth values. In contrast, higher levels of body fat and endomorphy were noted in this group. The proportion of mesomorphs and ectomorphs were similar in both groups. Futsal goalkeepers were differentiated by greater subcutaneous adiposity and body mass. Defenders had the slimmest body shape, with relatively narrower shoulders and hips, smaller bone breadths, and lower levels of adiposity. The body build of wingers was slightly larger. Pivoters were characterized by greater body height and larger values for the characteristics measuring the lateral trunk dimensions. Conclusions. The observed morphological differences between futsal and soccer players were mainly in body height and height-associated characteristics. This indicates that no specialized approach in futsal recruitment is currently used. This points to the need to develop a specialized approach in the player recruitment stage, as the tactical and

  1. Menstrual cycle disorders in female volleyball players.

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

    2013-07-01

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

  2. Are squash players protecting their eyes?

    Eime, R; Finch, C; Sherman, C; Garnham, A

    2002-01-01

    Methods: A survey of 303 players (aged ≥18 years) was conducted at three squash venues in Melbourne, Australia over a three week period in June 2000 to obtain information about protective eyewear use.

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

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

    2017-03-01

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

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

    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.

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

    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.

  6. Increased Complexities in Visual Search Behavior in Skilled Players for a Self-Paced Aiming Task

    Jingyi S. Chia

    2017-06-01

    Full Text Available The badminton serve is an important shot for winning a rally in a match. It combines good technique with the ability to accurately integrate visual information from the shuttle, racket, opponent, and intended landing point. Despite its importance and repercussive nature, to date no study has looked at the visual search behaviors during badminton service in the singles discipline. Unlike anticipatory tasks (e.g., shot returns, the serve presents an opportunity to explore the role of visual search behaviors in movement control for self-paced tasks. Accordingly, this study examined skill-related differences in visual behavior during the badminton singles serve. Skilled (n = 12 and less skilled (n = 12 participants performed 30 serves to a live opponent, while real-time eye movements were captured using a mobile gaze registration system. Frame-by-frame analyses of 662 serves were made and the skilled players took a longer preparatory time before serving. Visual behavior of the skilled players was characterized by significantly greater number of fixations on more areas of interest per trial than the less skilled. In addition, the skilled players spent a significantly longer time fixating on the court and net, whereas the less skilled players found the shuttle to be more informative. Quiet eye (QE duration (indicative of superior sports performance however, did not differ significantly between groups which has implications on the perceived importance of QE in the badminton serve. Moreover, while visual behavior differed by skill level, considerable individual differences were also observed especially within the skilled players. This augments the need for not just group-level analyses, but individualized analysis for a more accurate representation of visual behavior. Findings from this study thus provide an insight to the possible visual search strategies as players serve in net-barrier games. Moreover, this study highlighted an important aspect of

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

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

    2008-01-01

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

  8. Shoulder instability in professional football players.

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

    2013-09-01

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

  9. Understanding gaming floor influences on player behaviour

    Griffiths, MD

    2009-01-01

    Efforts to entice and retain player activity within a casino gaming environment require bringing to bear a range of sensory and physical influences. The challenge is to accomplish the operators’ objectives while at the same time ensuring any potential negative effects on the player are minimised. How casinos keep this in balance is at the heart of how the gaming floor works, and assessing such matters is becoming a necessary part of social responsibility.

  10. Decomposition of Multi-player Games

    Zhao, Dengji; Schiffel, Stephan; Thielscher, Michael

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

  11. Brain damage in former association football players

    Sortland, O.; Tysvaer, A.T.

    1989-01-01

    Thirty-three former football players from the National Football Team of Norway were examined by cerebral computer tomography (CT). The CT studies, evaluated for brain atrophy, visually and by linear measurements compared two different normal materials. One third of the players were found to have central cerebral atrophy. It is concluded that the atrophy probably was caused by repeated small head injuries during the football play, mainly in connection with heading the ball. (orig.)

  12. Clustering Professional Basketball Players by Performance

    Patel, Riki

    2017-01-01

    Basketball players are traditionally grouped into five distinct positions, but these designationsare quickly becoming outdated. We attempt to reclassify players into new groupsbased on personal performance in the 2016-2017 NBA regular season. Two dimensionalityreduction techniques, t-Distributed Stochastic Neighbor Embedding (t-SNE) and principalcomponent analysis (PCA), were employed to reduce 18 classic metrics down to two dimensionsfor visualization. k-means clustering discovered four grou...

  13. Relative age effect in FIFA U17 Emirates 2013 World Cup: analysis of players who effectively participated in the matches

    Victor Amorim Andrade-Souza

    2015-12-01

    Full Text Available Abstract The purpose of this study was to verify the date of birth is a decisive factor for the success of players selected by the coaches to participate in the FIFA U-17 World Cup Emirates 2013. The players' date of birth were classified into four quartiles of three months each (Q1 to Q4. In the qualifying round, 46.5% of the selected players born in Q1, while 12.5% in Q4. This significantly different distribution occurred until the semi-finals. However, in the final match, there were no significant differences between Q1 and Q4. A similar relative age effect also occurred when analyzed only players who actually participated to the matches. Interestingly, despite there was birth date effect on performance in all World Cup stages except in the final, other issues should take into consideration for a team became champion.

  14. Variations in Star Excursion Balance Test Performance Between High School and Collegiate Football Players.

    McCann, Ryan S; Kosik, Kyle B; Beard, Megan Q; Terada, Masafumi; Pietrosimone, Brian G; Gribble, Phillip A

    2015-10-01

    The Star Excursion Balance Test (SEBT) is a reliable inexpensive tool used to assess dynamic postural control deficits and efficacy in the prediction of musculoskeletal injuries, but with little previous consideration for performance differences across age and skill levels. The purpose of this study was to examine differences in SEBT scores between high school and collegiate football players. Three-hundred eighteen high school football players and 180 National Collegiate Athletic Association Division I collegiate football players volunteered to participate. Star Excursion Balance Test scores were obtained bilaterally for anterior (ANT), posterolateral (PL), and posteromedial (PM) directions, and for an overall composite (COMP) score. The mean of 3 trials from each leg was normalized to stance leg length and presented as a percentage score. Bilaterally averaged scores were compared between high school and collegiate football players using separate independent t-tests. A multiple linear backward regression determined the amount of variance in SEBT scores explained by age, mass, and height. Compared with collegiate athletes, high school athletes had lower PL (72.8 ± 11.4% vs. 77.1 ± 10.2%; p football players.

  15. Bridging Media with the Help of Players

    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.

  16. The audiological health of horn players.

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

    2013-01-01

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

  17. Player Skill Decomposition in Multiplayer Online Battle Arenas

    Chen, Zhengxing; Sun, Yizhou; El-nasr, Magy Seif; Nguyen, Truong-Huy D.

    2017-01-01

    Successful analysis of player skills in video games has important impacts on the process of enhancing player experience without undermining their continuous skill development. Moreover, player skill analysis becomes more intriguing in team-based video games because such form of study can help discover useful factors in effective team formation. In this paper, we consider the problem of skill decomposition in MOBA (MultiPlayer Online Battle Arena) games, with the goal to understand what player...

  18. A simple video-based timing system for on-ice team testing in ice hockey: a technical report.

    Larson, David P; Noonan, Benjamin C

    2014-09-01

    The purpose of this study was to describe and evaluate a newly developed on-ice timing system for team evaluation in the sport of ice hockey. We hypothesized that this new, simple, inexpensive, timing system would prove to be highly accurate and reliable. Six adult subjects (age 30.4 ± 6.2 years) performed on ice tests of acceleration and conditioning. The performance times of the subjects were recorded using a handheld stopwatch, photocell, and high-speed (240 frames per second) video. These results were then compared to allow for accuracy calculations of the stopwatch and video as compared with filtered photocell timing that was used as the "gold standard." Accuracy was evaluated using maximal differences, typical error/coefficient of variation (CV), and intraclass correlation coefficients (ICCs) between the timing methods. The reliability of the video method was evaluated using the same variables in a test-retest analysis both within and between evaluators. The video timing method proved to be both highly accurate (ICC: 0.96-0.99 and CV: 0.1-0.6% as compared with the photocell method) and reliable (ICC and CV within and between evaluators: 0.99 and 0.08%, respectively). This video-based timing method provides a very rapid means of collecting a high volume of very accurate and reliable on-ice measures of skating speed and conditioning, and can easily be adapted to other testing surfaces and parameters.

  19. Rules of engagement : influence of co-player presence on player involvement in digital games

    Gajadhar, B.J.; Kort, de Y.A.W.; IJsselsteijn, W.A.

    2009-01-01

    This article presents an empirical study of social setting as a determinant of player involvement in competitive play. We conceptualize player experience as comprising of components of involvement and enjoyment. Involvement relates to the attentional pull of games encompassing feelings of immersion,

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

    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 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).

  1. Sports injuries in Plus League volleyball players.

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

    2015-06-01

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

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

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

    2014-09-01

    , and competitive level of the teams influence physical and temporal characteristics, and they may be taken into consideration during the training by strength and conditioning coaches and coaches.More experienced players adopt strategies to better manage their effort and rest time between rallies.The game strategy affects the physical actions done by players (e.g. tendency to serve more to one player of the team affects the number of jumps performed by this player).

  3. Injuries in Spanish female soccer players

    Juan Del Coso

    2018-04-01

    Full Text Available Background: Epidemiologic research to learn the incidence, type, location, and severity of female soccer injuries and the risk factors for sustaining a sport injury is the first step in developing preventive policies. The aim of this study was to analyze the incidence of injuries in the population of female soccer players in Spain. Methods: The injuries incurred by 25,397 female soccer players were registered by the medical staff of the Spanish Football Federation during 1 season. A standardized medical questionnaire was used to classify the injury according to type, severity, location, and injury mechanism. A total of 2108 injuries was reported with an incidence of 0.083 injuries per player per season. Most injuries were in the lower limbs (74.0%, mainly affecting knee (30.4% and ankle joints (17.9%. Results: The proportion of injuries derived from contact with another player was higher during matches (33.7% than during training (11.4%; p  0.05. Conclusion: Most female soccer injuries were located at the knee and ankle; the injury mechanism determined the playing time lost; and the player's age did not affect injury characteristics. Keywords: Ankle, Epidemiology, Knee, Sport injuries, Women

  4. Player Modeling for Intelligent Difficulty Adjustment

    Missura, Olana; Gärtner, Thomas

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

  5. Game Performance Evaluation in Male Goalball Players

    Molik, Bartosz; Morgulec-Adamowicz, Natalia; Kosmol, Andrzej; Perkowski, Krzysztof; Bednarczuk, Grzegorz; Skowroński, Waldemar; Gomez, Miguel Angel; Koc, Krzysztof; Rutkowska, Izabela; Szyman, Robert J

    2015-01-01

    Goalball is a Paralympic sport exclusively for athletes who are visually impaired and blind. The aims of this study were twofold: to describe game performance of elite male goalball players based upon the degree of visual impairment, and to determine if game performance was related to anthropometric characteristics of elite male goalball players. The study sample consisted of 44 male goalball athletes. A total of 38 games were recorded during the Summer Paralympic Games in London 2012. Observations were reported using the Game Efficiency Sheet for Goalball. Additional anthropometric measurements included body mass (kg), body height (cm), the arm span (cm) and length of the body in the defensive position (cm). The results differentiating both groups showed that the players with total blindness obtained higher means than the players with visual impairment for game indicators such as the sum of defense (p = 0.03) and the sum of good defense (p = 0.04). The players with visual impairment obtained higher results than those with total blindness for attack efficiency (p = 0.04), the sum of penalty defenses (p = 0.01), and fouls (p = 0.01). The study showed that athletes with blindness demonstrated higher game performance in defence. However, athletes with visual impairment presented higher efficiency in offensive actions. The analyses confirmed that body mass, body height, the arm span and length of the body in the defensive position did not differentiate players’ performance at the elite level. PMID:26834872

  6. Game Performance Evaluation in Male Goalball Players

    Molik Bartosz

    2015-12-01

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

  7. Greater circadian disadvantage during evening games for the National Basketball Association (NBA), National Hockey League (NHL) and National Football League (NFL) teams travelling westward.

    Roy, Jonathan; Forest, Geneviève

    2018-02-01

    We investigated the effects of a circadian disadvantage (i.e. playing in a different time zone) on the winning percentages in three major sport leagues in North America: the National Basketball Association, the National Hockey League and the National Football League. We reviewed 5 years of regular season games in the National Basketball Association, National Hockey League and National Football League, and noted the winning percentage of the visiting team depending on the direction of travel (west, east, and same time zone) and game time (day and evening games). T-tests and analysis of variance were performed to evaluate the effects of the circadian disadvantage, its direction, the number of time zones travelled, and the game time on winning percentages in each major league. The results showed an association between the winning percentages and the number of time zones traveled for the away evening games, with a clear disadvantage for the teams travelling westward. There was a significant difference in the teams' winning percentages depending on the travelling direction in the National Basketball Association (F 2,5908  = 16.12, P < 0.0001) and the National Hockey League (F 2,5639  = 4.48, P = 0.011), and a trend was found in the National Football League (F 2,1279  = 2.86, P = 0.058). The effect of the circadian disadvantage transcends the type of sport and needs to be addressed for greater equity among the western and eastern teams in professional sports. These results also highlight the importance of circadian rhythms in sport performance and athletic competitions. © 2017 European Sleep Research Society.

  8. "Strategic" and "tactical" chess differentiate in their hippocampal and precuneus requirements in expert chess players

    Wallentin, Mikkel; Roepstorff, Andreas; Vestergaard-Poulsen, Peter

    Introduction Expert chess players have been a popular population for research in acquired expertise. The putative cognitive underpinnings of chess-expertise (eg. IQ and memory) have been sought for with mixed results. We suggest that this may be partly due to a lack of detail in the analysis...... of the game itself. We investigated whether different types of chess positions, known as "tactical" and "strategic", activates different neurocognitive structures. In a tactical position the choice of move determines the game, whereas strategic moves are based on long term considerations and do not imply...... an immediate determination. We therefore hypothesised that tactical considerations rely more on working memory (WM) brain structures, such as the precuneus , while strategic rely on long term memory (LTM), i.e. hippocampus. Methods 22 chess-players participated, 9 during fMRI scanning in a 3T scanner while...

  9. Cold power creates artificial ice for the ice hockey championship. Football arena is used as an ice stadium; Kaeltepower schafft Kunsteis fuer Eishockey-WM. Fussballarena wird zum Eisstadion

    Hoffmann, Franz

    2010-11-15

    On 7th May 2010, the Veltins arena in Gelsenkirchen (Federal Republic of Germany) became the greatest ice hockey stadium of the world. There, the opening play of the world championship between the host Germany and the USA took place. Germany as a clear outsider won 2:1 against the US-Boys. However, before this historical victory extensive building operations had to be realized 'Auf Schalke' in order to convert the lawn into a complete ice hockey court.

  10. Motivation and Sport Injuries in Handball Players

    Laguna, María

    2010-12-01

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

  11. Cricket club looking for new players

    Cricket Club

    2016-01-01

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

  12. There is no game without a player

    Larsen, Lasse Juel

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

  13. Modelling Virtual Camera Behaviour Through Player Gaze

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

    2012-01-01

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

  14. Mean Field Games with a Dominating Player

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

    2016-08-15

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

  15. Towards Player-Driven Procedural Content Generation

    Shaker, Noor

    Generating immersive game content is one of the ultimate goals for a game designer. This goal can be achieved taken into account that players’ perceptions of the same game differ according to a number of factors including: players’ personality, playing styles, expertise and cultural background. One...... promising avenue towards optimizing the gameplay experience for individual game players - and thereby attempt to close the affective loop in games - is to automatically tailor the game content in real-time. To realize player-driven procedural content generation one needs to specify the aspects of the game...... that have a key influence on the gameplay experience, identify the relationship between these aspects and player experience and define a mechanism for tailoring the game content to each individual needs. In this dissertation we attempt to address the following research questions towards the aim...

  16. Big Data for Business Ecosystem Players

    Perko Igor

    2016-06-01

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

  17. Relationship between anthropometric measures and sagittal spinal curvatures in adult male handball players

    Ameer Mariam Abdul-Moneem

    2017-12-01

    Full Text Available Purpose. Increasing anthropometric measures bring considerable spinal loads during sports practice, which inversely affects the adaptation abilities of the spinal structures; this in turn influences the spinal curvatures. The study was conducted to explore the relationship between anthropometric measures and sagittal spinal curvatures in handball players. Method. The total of 83 male handball players were divided into 2 groups, depending on their body height: group 1 (age, 23.62 ± 2.07 years consisted of 40 handball players with height above average, group 2 (age, 24.63 ± 2.58 years consisted of 43 handball players with height below average. The thoracic and lumbar curvatures and trunk height were measured with the Formetric III 4D spine and posture analysis system. Results. The thoracic kyphosis of group 1 was significantly higher than that of group 2 (p = 0.038, without a significant difference in lumbar lordosis (p = 0.312, and significant difference in the coefficient of compensation between thoracic kyphosis and lumbar lordosis (p = 0.026. Group 1 showed strong positive correlation between body height and kyphotic angle (r = 0.897, and moderate positive correlation with lordosis angle (r = 0.496. In group 2, there was weak positive correlation with kyphotic angle (r = 0.381, and weak negative correlation with lumbar lordosis angle (r = -0.355. Conclusions. Increasing body height of handball players is associated with bigger kyphotic and lordotic angles. Owing to frequent sagittal asymmetric overloading of the spine during handball training, exercises that help maintain good posture and correct the thoracic kyphosis are required, especially for taller players.

  18. Short-term Outcomes Following Concussion in the NFL: A Study of Player Longevity, Performance, and Financial Loss.

    Navarro, Sergio M; Sokunbi, Olumide F; Haeberle, Heather S; Schickendantz, Mark S; Mont, Michael A; Figler, Richard A; Ramkumar, Prem N

    2017-11-01

    A short-term protocol for evaluation of National Football League (NFL) athletes incurring concussion has yet to be fully defined and framed in the context of the short-term potential team and career longevity, financial risk, and performance. To compare the short-term career outcomes for NFL players with concussions by analyzing the effect of concussions on (1) franchise release rate, (2) career length, (3) salary, and (4) performance. Cohort study; Level of evidence, 3. NFL player transaction records and publicly available injury reports from August 2005 to January 2016 were analyzed. All players sustaining documented concussions were evaluated for a change to inactive or DNP ("did not participate") status. A case-control design compared franchise release rates and remaining NFL career span. Career length was analyzed via survival analysis. Salary and performance differences were analyzed with publicly available contract data and a performance-scoring algorithm based on position/player level. Of the 5894 eligible NFL players over the 11-year period, 307 sustained publicly reported concussions resulting in the DNP injury protocol. Analysis of the probability of remaining in the league demonstrated a statistically significantly shorter career length for the concussion group at 3 and 5 years after concussion. The year-over-year change in contract value for the concussion group resulted in a mean overall salary reduction of $300,000 ± $1,300,000 per year (interquartile range, -$723,000 to $450,000 per year). The performance score reduction for all offensive scoring players sustaining concussions was statistically significant. This retrospective study demonstrated that NFL players who sustain a concussion face a higher overall franchise release rate and shorter career span. Players who sustained concussions may incur significant salary reductions and perform worse after concussion. Short-term reductions in longevity, performance, and salary after concussion exist and

  19. Self-determined motivation in rehabilitating professional rugby union players

    Carson, F.; Polman, Remco C.J.

    2017-01-01

    Background The aim of the present study was to explore the views of professional rugby union players during the early rehabilitation, late rehabilitation and return to play stages, following anterior cruciate ligament (ACL) injury. Methods A qualitative dominant, mixed methodological approach was utilized with five players who had suffered an ACL injury requiring reconstructive surgery. A longitudinal approach, concurrent with each player?s rehabilitation, consisting of twice monthly intervie...

  20. Effect of coach change on professional tennis players

    Nekolová, Barbora

    2014-01-01

    Title: Effect of coach change on professional tennis players Objectives of work: The aim of the thesis is to analyze the impact of coach change on professional tennis players from the psychology perspective, social relationship and player's attitude to the sport itself. The impact of the coach change on player's approach to tennis, game results, personal life and interpersonal relationships will be examined. Method: The methods that will be used are narrative interviews - annotated transcript...

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

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

    2010-01-01

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

  2. Coping strategies of soccer players | Plaatjie | South African Journal ...

    This study focused on coping strategies used by soccer (football) players by exploring the role of the environment, ethnicity and culture in players' response to stressful situations. An interpretive-qualitative research methodology was applied with a sample of 33 professional soccer players. The subjects were representative ...

  3. Exploring Online Game Players' Flow Experiences and Positive Affect

    Chiang, Yu-Tzu; Lin, Sunny S. J.; Cheng, Chao-Yang; Liu, Eric Zhi-Feng

    2011-01-01

    The authors conducted two studies to explore online game players' flow experiences and positive affect. Our findings indicated that online game are capable of evoking flow experiences and positive affect, and games of violent or nonviolent type may not arouse players' aggression. The players could be placed into four flow conditions: flow,…

  4. High School Rugby Players' Perception of Coaching Effectiveness

    Broodryk, Retief; van den Berg, Pieter Hendrick

    2011-01-01

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

  5. Morphological evolution of Springbok rugby players: Implications for ...

    The physique of rugby players has evolved over the course of the Twentieth Century. A novel morphological dataset was constructed of all Springbok rugby players until 2014. Although most of the change in body structure, particularly body weight, occurs during the era of professionalism, white Springbok rugby players ...

  6. Training Patterns of Wheelchair Basketball Players in Turkey

    Tatar, Yasar

    2008-01-01

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

  7. Foot morphology of Turkish football players according to foot ...

    Football is the most popular sport in the world. Foot morphology and foot preference are important factors in football player's performance. The aim of this cross-sectional study was to evaluate the foot morphology of elite football players with different foot preferences. 407 male football players participated in this study. 328 of ...

  8. Injury prevention for adult male soccer players

    van Beijsterveldt, A.M.C.

    2013-01-01

    Soccer causes the largest number of injuries each year (18% of all sports injuries) in the Netherlands. The aim of this dissertation is to contribute to the body of evidence on injury prevention for adult male soccer players. Chapter 1 is a general introduction and presents the “sequence of

  9. The players in the French photovoltaic sector

    Houot, G.

    2011-01-01

    This article reviews all the players of the photovoltaic industry in France (silicon producers, electrical component manufacturers, solar system manufacturers, design offices, solar system wholesalers, installers, and solar farm operators). For each company the following is reported: name, activity sector, historical background, staff, turnover, achievement and projects. (A.C.)

  10. Are squash players protecting their eyes?

    Eime, R M; Finch, C F; Sherman, C A; Garnham, A P

    2002-09-01

    To determine factors associated with adult squash players' protective eyewear behaviours. A survey of 303 players (aged >or =18 years) was conducted at three squash venues in Melbourne, Australia over a three week period in June 2000 to obtain information about protective eyewear use. Of 303 participants the response rate was 98.1%; 66.1% were males, with a mean age of 40.5 years. The majority (68.4%) had played squash for 10 years or more. Although 18.8% of players reported using protective eyewear, only 8.9% reported wearing approved eyewear. Both age group (peye injuries (50.0%) and knowledge of eye injury risk (33.9%). A commonly reported barrier was restriction of vision (34.2%). These findings demonstrate a low prevalence of voluntary use of appropriate protective eyewear. Future prevention strategies incorporating education campaigns should focus on increasing players' knowledge of risks. The barriers to use and misconceptions about which types of eyewear is most protective need to be addressed as a priority.

  11. Acromioclavicular disruption in first class rugby players.

    Webb, J; Bannister, G

    1992-01-01

    In a random sample of 105 first class rugby players, 45% gave a history of injury of the acromioclavicular joint. All continued to play at the highest level. The effects of the injury appeared to be minimal. Supraspinatus impingement syndrome commonly associated with acromioclavicular pathology was sought, but not found.

  12. Kinanthropometric characteristics in teenager basketball players

    Maria Abella del Campo

    2015-12-01

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

  13. Modeling attacking of high skills volleyball players

    Vladimir Gamaliy

    2014-12-01

    Full Text Available Purpose: to determine the model indicators of technical and tactical actions in the attack highly skilled volleyball players. Material and Methods: the study used statistical data of major international competitions: Olympic Games – 2012 World Championships – 2010, World League – 2010–2014 European Championship – 2010–2014. A total of 130 analyzed games. Methods were used: analysis and generalization of scientific and methodological literature, analysis of competitive activity highly skilled volleyball players, teacher observation, modeling technical and tactical actions in attacking highly skilled volleyball players. Results: it was found that the largest volume application of technical and tactical actions in the attack belongs to the group tactics «supple movement», whose indicator is 21,3%. The smallest amount of application belongs to the group tactics «flight level» model whose indicators is 5,4%, the efficiency of 3,4%, respectively. It is found that the power service in the jump from model parameters used in 51,6% of cases, the planning targets – 21,7% and 4,4% planning to reduce. Attacks performed with the back line, on model parameters used in the amount of 20,8% efficiency –13,7%. Conclusions: we prove that the performance of technical and tactical actions in the attack can be used as model in the control system of training and competitive process highly skilled volleyball players

  14. Comparative analysis of the physique of volleyball players selected from different volleyball clubs

    Adrian Sieroń

    2017-12-01

    Full Text Available In recent years we have seen a steady increase in interest in sport among the public. This is due primarily to the deepening of knowledge about the health-promoting aspects for people who practice it regularly. Considerable interest primarily characterized by team games, which due to their accessibility, clearly defined rules, the variety of forms of movement, or finally, the interaction between human are the most popular sport disciplines. In Poland, one of the most popular team sports of football is next to volleyball. From year to year, this form of recreation is more and more supporters.  For many years, extremely important for researchers from around the world was to find the factors that determine the achievement of high results volleyball. This problem is steadily gaining in importance, because modern training methods contribute to maximizing the potential of each player. Many researchers believe that making attempts to find factors that are of potential players is one of the few areas where you can find the reserves to increase results. The aim of this study is to compare intergroup somatic athletes practicing volleyball, playing and trainees in four different teams in Lower Silesia. The study enrolled 54 men aged 12-15 years with a group of four volleyball players representing the same level of sports preparation. The study used data measuring 17 somatic features. The results show that the somatic features of individual players in all four teams are similar and homogeneous.

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

    Cortsen, Kenneth

    2016-01-01

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

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

    Cortsen, Kenneth

    2014-01-01

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

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

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

    2014-09-01

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

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

    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.

  19. Body Image Amongst Elite Rugby Union Players.

    Gibson, Claire; Hindle, Chloe; McLay-Cooke, Rebecca; Slater, Joanne; Brown, Rachel; Smith, Brett; Baker, Dane; Healey, Philip; Black, Katherine

    2017-11-16

    There is limited information on the risk of eating disorders and body image of elite male athletes. However, research suggests there are some athletes who have poor body image and they may be at increased risk of developing eating disorders. Therefore, the current study investigated risk of eating disorders, body image, and the relationship with age, in elite rugby union players during their pre-season training period.This cross-sectional study was undertaken at the start of the pre-season amongst elite rugby union players in New Zealand. Twenty-six professional rugby union players completed a 49-item questionnaire on body image and disordered eating. A 'body image score' was calculated from questionnaire subscales including 'drive for thinness', 'bulimia' and 'body dissatisfaction', with total scores above twenty indicative of poor body image.Body image scores varied from 8-39 out of a possible 0-100. Disordered eating behaviours were reported, including binge eating at least once a week (15%, n=4/26), pathogenic weight control use (4%, n=1/26) and avoidance of certain foods (77%, n=20/26). There was a statistically significant inverse association between the bulimia subscale and age (P = 0.034).At the start of the pre-season training period, many elite rugby union players experience disturbances in body image. The prevalence of disordered eating behaviours is of concern, and needs to be minimised due to the negative impact on health and performance. A focus on assessment and education of younger male rugby players may be required in order to reduce disordered eating patterns.

  20. Physiological characteristics of elite soccer players.

    Tumilty, D

    1993-08-01

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

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

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

    2015-01-01

    Background: There is a scarcity of literature evaluating injuries in youth fast-pitch softball players. Purpose: To perform a descriptive analysis of player-reported injuries in youth fast-pitch softball position players and pitchers during a single select-level season. Study Design: Prospective observation cohort study. Level of Evidence: Level 3. Methods: Ninety-eight athletes (48 pitchers, 50 position players) were followed for a single select fast-pitch softball season. Study participants completed web-based surveys every 3 weeks reporting injuries related to participation in fast-pitch softball. Injury was defined as pain causing cessation of participation in the current game or practice that prevents the player’s return to that session or any pain that causes cessation of a player’s customary participation on the day after the day of onset. Results: The median age of the study participants was 14 years (range, 9-18 years). There were 49 reported injuries in 98 athletes. The average age was 13 years for those not injured and 14 years for those who were injured (P softball players. Better off-season and preseason conditioning may be a key factor for reducing pitching injuries. Clinical Relevance: Recognition of injury patterns in fast-pitch softball players is critical to developing strategies to keep these athletes competing safely. PMID:26502442

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

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

    2015-01-01

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

  3. I Fought the Law: Transgressive Play and The Implied Player

    Aarseth, Espen J.

    2007-01-01

    This paper is an attempt to understand Game Studies through the contested notion of the “player” both inside and outside “the game object” – that is the object that game users perceive and respond to when they play. Building on Hans-Georg Gadamer’s notion of games as a subject that “masters...... the players”, the paper will go beyond the traditional split between the social sciences’ real players and the aesthetics/humanities critical author-as-player, and present a theory of the player and player studies that incorporates the complex tensions between the real, historical player and the game’s human...... components. Since games are both aesthetic and social phenomena, a theory of the player must combine both social and aesthetic perspectives to be successful. The tension between the humanities and the social sciences over who controls the idea of the player can be found mirrored also in the struggle between...

  4. Does “Live High-Train Low (and High” Hypoxic Training Alter Running Mechanics In Elite Team-sport Players?

    Olivier Girard, Grégoire P. Millet, Jean-Benoit Morin, Franck Brocherie

    2017-09-01

    Full Text Available This study aimed to investigate if “Live High-Train Low (and High” hypoxic training alters constant-velocity running mechanics. While residing under normobaric hypoxia (≥14 h·d-1; FiO2 14.5-14.2% for 14 days, twenty field hockey players performed, in addition to their usual training in normoxia, six sessions (4 × 5 × 5-s maximal sprints; 25 s passive recovery; 5 min rest under either normobaric hypoxia (FiO2 ~14.5%, n = 9 or normoxia (FiO2 20.9%, n = 11. Before and immediately after the intervention, their running pattern was assessed at 10 and 15 km·h-1 as well as during six 30-s runs at ~20 km·h-1 with 30-s passive recovery on an instrumented motorised treadmill. No clear changes in running kinematics and spring-mass parameters occurred globally either at 10, 15 or ~20 km·h-1, with also no significant time × condition interaction for any parameters (p > 0.14. Independently of the condition, heart rate (all p < 0.05 and ratings of perceived exertion decreased post-intervention (only at 15 km·h-1, p < 0.05. Despite indirect signs for improved psycho-physiological responses, no forthright change in stride mechanical pattern occurred after “Live High-Train Low (and High” hypoxic training.

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

    Grgantov, Zoran; Milić, Mirjana; Katić, Ratko

    2013-05-01

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

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

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

    2009-03-01

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

  7. The isokinetic strength profile of elite soccer players according to playing position.

    Robert Śliwowski

    Full Text Available The aim of this study was to compare isokinetic strength performance profiles in elite soccer players across different field positions. A total of 111 elite international players of Polish Ekstraklasa (the top division in Poland were examined during the 2010-2015 seasons. The players were classified into six positional roles: central defenders (CD, external defenders (ED, central midfielders (CM, external midfielders (EM, forwards (F, and goalkeepers (G. The concentric isokinetic strength (peak torque [PT] of quadriceps and hamstrings, H/Q ratios was calculated for the dominant leg and the non-dominant leg at angular velocity of 1.05 rad ·s-1, whereas to assess isokinetic muscle endurance, the total work [TW] at angular velocity of 4.19 rad ·s-1, was taken into consideration. The results showed that isokinetic strength performance varies significantly among players in different playing positions. The analysis of PT for quadriceps (PT-Q and hamstrings (PT-H generally showed that the goalkeepers and central midfielders had lower strength levels compared to other playing positions. In the case of PT-H and hamstring/quadricep (H/Q peak torque ratios, statistically significant differences were also noted for the legs, where mean values noted for the dominant leg were higher than for the non-dominant leg. For TW for quadriceps (TW-Q and hamstrings (TW-H, statistically significant differences were noted only between playing positions. TW-Q values for goalkeepers were lower than for central defenders and external midfielders. TW-H values for goalkeepers were lower than for central midfielders, central defenders and external midfielders. This study showed that specific functional activity of players in individual positions on the field influences the varied profile of isokinetic strength performance.

  8. Operative shoulder instability injury management in Australian Football League players: A case series.

    Bonacci, Jason; Manson, Brent; Bowe, Steven J; Gill, Stephen; Seward, Hugh; Hoy, Greg; Page, Richard

    2017-11-27

    The purpose of this study was to review the surgical management procedures of shoulder instability injuries in Australian Football League (AFL) players, and determine outcomes regarding return to sport and injury recurrence. Retrospective cohort study. Elite AFL players with shoulder instability resulting in surgery were assessed in a retrospective cohort design (72 players/77 shoulders). Type of initial injury, surgical management, return to sport and injury recurrence were obtained. The mean follow-up period post-surgery was 2.9 years. Return to sport outcomes were compared between arthroscopic and open surgery using a Kaplan-Meier survival analysis. Logistic regression modelling was used to determine associations between injury recurrence, type of injury, participant age and method of surgery. Shoulder instability injuries occurred most frequently during tackling (40%). Arthroscopic surgery was preferred for primary shoulder instability. Nine (16%) recurrences occurred in those who underwent arthroscopic surgery compared to two (9%) following open surgery. Return to the elite level was slightly but significantly (2 weeks, p=0.049) longer for open compared to arthroscopic surgery. Recurrence was 5 times more likely if the primary injury was a dislocation and more likely in players who were younger at the time of surgery. Tackling was the predominant mechanism for shoulder instability injuries in AFL players and arthroscopic surgery was more commonly performed for primary injuries. Sustaining a dislocation as the primary injury and younger age increased the likelihood of recurrent instability. Careful consideration should be given to the operative management of these individuals. Copyright © 2017. Published by Elsevier Ltd.

  9. Does “Live High-Train Low (and High)” Hypoxic Training Alter Running Mechanics In Elite Team-sport Players?

    Girard, Olivier; Millet, Grégoire P.; Morin, Jean-Benoit; Brocherie, Franck

    2017-01-01

    This study aimed to investigate if “Live High-Train Low (and High)” hypoxic training alters constant-velocity running mechanics. While residing under normobaric hypoxia (≥14 h·d-1; FiO2 14.5-14.2%) for 14 days, twenty field hockey players performed, in addition to their usual training in normoxia, six sessions (4 × 5 × 5-s maximal sprints; 25 s passive recovery; 5 min rest) under either normobaric hypoxia (FiO2 ~14.5%, n = 9) or normoxia (FiO2 20.9%, n = 11). Before and immediately after the intervention, their running pattern was assessed at 10 and 15 km·h-1 as well as during six 30-s runs at ~20 km·h-1 with 30-s passive recovery on an instrumented motorised treadmill. No clear changes in running kinematics and spring-mass parameters occurred globally either at 10, 15 or ~20 km·h-1, with also no significant time × condition interaction for any parameters (p > 0.14). Independently of the condition, heart rate (all p < 0.05) and ratings of perceived exertion decreased post-intervention (only at 15 km·h-1, p < 0.05). Despite indirect signs for improved psycho-physiological responses, no forthright change in stride mechanical pattern occurred after “Live High-Train Low (and High)” hypoxic training. Key points There are indirect signs for improved psycho-physiological responses in responses to “Live High-Train Low (and High)” hypoxic training. This hypoxic training regimen, however, does not modify the running mechanics of elite team-sport players at low and high velocities. Coaches can be confident that this intervention, known for inducing significant metabolic benefits, is appropriate for athletes since their running kinetics and kinematics are not negatively affected by chronic hypoxic exposure. PMID:28912649

  10. Common Injuries of Collegiate Tennis Players

    Christian Wisdom Magtajas Valleser

    2017-09-01

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

  11. Evolutionary game theory: molecules as players.

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

    2014-12-01

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

  12. Predicting Player Churn In the Wild

    Hadiji, Fabian; Sifa, Rafet; Drachen, Anders

    2014-01-01

    Free-to-Play or "freemium" games represent a fundamental shift in the business models of the game industry, facilitated by the increasing use of online distribution platforms and the introduction of increasingly powerful mobile platforms. The ability of a game development company to analyze...... a crucial value, allowing developers to obtain data-driven insights to inform design, development and marketing strategies. One of the key challenges is modeling and predicting player churn. This paper presents the first cross-game study of churn prediction in Free-to-Play games. Churn in games is discussed...... and derive insights from behavioral telemetry is crucial to the success of these games which rely on in-game purchases and in-game advertising to generate revenue, and for the Company to remain competitive in a global marketplace. The ability to model, understand and predict future player behavior has...

  13. Player Transformation of Educational Multiplayer Games

    Magnussen, Rikke; Misfeldt, Morten

    2004-01-01

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

  14. Player-Specific Conflict Handling Ontology

    Charline Hondrou

    2014-09-01

    Full Text Available This paper presents an ontology that leads the player of a serious game - regarding conflict handling - to the educative experience from which they will benefit the most. It provides a clearly defined tree of axioms that maps the player’s visually manifested affective cues and emotional stimuli from the serious game to conflict handling styles and proposes interventions. The importance of this ontology lies in the fact that it promotes natural interaction (non-invasive methods and at the same time makes the game as player-specific as it can be for its educational goal. It is an ontology that can be adapted to different educational theories and serve various educational purposes.

  15. Telemetry and Communication IP Video Player

    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.

  16. Management Of The Critically Injured Football Player

    Feld, Francis

    1993-01-01

    Evaluation and treatment of a football player who has sustained life-threatening injuries is a rare but significant challenge for the sports medicine team. Early recognition and intervention in these injuries is crucial. Helmets and shoulder pads complicate management of these patients. In this article, I present a rapid and simple assessment method used by paramedics for trauma patients. Treatment focuses on when football equipment should be removed and how the equipment complicates Advanced...

  17. Do economic players shape up fashion trends?

    Hasan, Syed Akif; Subhani, Muhammad Imtiaz; Osman, Ms. Amber

    2012-01-01

    The behavior of following the most in vogue and admired styles of dressing has been there since the ancient times. With time, people have moved on with the rapid change in the surroundings. Both the genders acknowledge fashion. Fashion is an extension of regular clothing. This paper investigates the role of economical players which includes per capita income and inflations in shaping up the various trends/ fashion trends/ trends in clothing and their consumptions for Pakistan, India, United S...

  18. Nutrition and Gaelic football: review, recommendations, and future considerations.

    Beasley, Kevin J

    2015-02-01

    Gaelic football is the second most popular team sport in Ireland in terms of participation. However, very little research exists on the nutritional considerations for elite male Gaelic footballers. Gaelic football is an intermittent type field game played by two teams of fifteen players. Although amateurs, elite players may train and compete 4-5 times per week and may play for several teams. Research suggests that elite footballers are similar anthropometrically and in fitness to professional soccer players. Work-rate analysis shows that footballers experience longer durations of high-intensity (HI) activity (5-7s) and shorter rest durations than soccer players. Recent data suggests that half-forward/backs perform a greater amount of HI work during games than players in other positions. Fatigue is apparent between the first and second halves and the first and fourth quarters. The limited amount of nutritional studies conducted implies that footballers may be deficient in energy intake and may be at the lower end of recommended carbohydrate intakes to support training. A wide variety of sweat rates have been measured during training, demonstrating the importance of individual hydration strategies. Ergogenic aids such as creatine and caffeine may prove beneficial to performance, although data are extrapolated from other sports. Due to the lack of research in Gaelic football, further population specific studies are required. Future areas of research on the impact of nutrition on Gaelic football performance are examined. In particular, the creation of a test protocol mimicking the activity patterns and intensity of a Gaelic football game is warranted.

  19. Preparation of reserve and player selection for the national basketball team

    Bezmylov Nikolay

    2016-06-01

    Full Text Available The model of selecting athletes to the national basketball team was substantiated taking into consideration the specific features of competitive activity and the age of athletes. The issue of the selection and training of basketball reserve for the national team of the country is discussed. The need was demonstrated for the use of multi-stage model of the selection of elite players for the national team, which includes: 1 preliminary selection; 2 intermediate selection; and 3 main selection. To evaluate athlete’s performance, the system of informative criteria and indicators was proposed. The features of the selection of the players of different age groups to club and national teams were described. The necessity for continuous and gradual upgrade of team roster was justified.

  20. The jumping action's indices of female volleyball players and their relation at some somatic characteristics

    Stech M.

    2010-02-01

    Full Text Available In the paper the results of correlation analysis between of most significance jumping action's indices of high performance polish female volleyball players and their some somatic characteristics (stature, weight and body composition indices: BMI, FATkg, FAT%, FFMkg,FFM%, TBWkg and TBW% are presented. It has been found close correlation between of height of attack jump and stature (r=0,98, weight (r=0,76, FFMkg(r=0,88 and TBWkg (r=0,88. But correlation of height of attack jump with FFM% and TBW% was nonessential. Statistical essential correlation between basic indices of plyometric factor and FAT%, FFM% and TBW% indices (accordingly r = -0,65; 0,65 and 0,66 has been found. The results of the study may be taking into consideration in order to elaboration of effective jumping methods for volleyball players.

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

    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

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

    Bon Marta

    2016-04-01

    Full Text Available 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.

  3. Resting ECG findings in elite football players.

    Bohm, Philipp; Ditzel, Roman; Ditzel, Heribert; Urhausen, Axel; Meyer, Tim

    2013-01-01

    The purpose of the study was to evaluate ECG abnormalities in a large sample of elite football players. Data from 566 elite male football players (57 of them of African origin) above 16 years of age were screened retrospectively (age: 20.9 ± 5.3 years; BMI: 22.9 ± 1.7 kg · m(-2), training history: 13.8 ± 4.7 years). The resting ECGs were analysed and classified according to the most current ECG categorisation of the European Society of Cardiology (ESC) (2010) and a classification of Pelliccia et al. (2000) in order to assess the impact of the new ESC-approach. According to the classification of Pelliccia, 52.5% showed mildly abnormal ECG patterns and 12% were classified as distinctly abnormal ECG patterns. According to the classification of the ESC, 33.7% showed 'uncommon ECG patterns'. Short-QT interval was the most frequent ECG pattern in this group (41.9%), followed by a shortened PR-interval (19.9%). When assessed with a QTc cut-off-point of 340 ms (instead of 360 ms), only 22.2% would have had 'uncommon ECG patterns'. Resting ECG changes amongst elite football players are common. Adjustment of the ESC criteria by adapting proposed time limits for the ECG (e.g. QTc, PR) should further reduce the rate of false-positive results.

  4. Hip and Groin Injuries in Baseball Players.

    Mlynarek, Ryan A; Coleman, Struan H

    2018-03-01

    To discuss the clinical significance of the most common hip and groin injuries in baseball players, as well as an algorithmic approach to diagnosis and treatment of these injuries. (a) Limitations in throwing velocity, pitch control, and bat swing speed may be secondary to decreased mobility and strength within the proximal kinetic chain, which must harness power from the lower extremities and core. (b) Approximately 5.5% of all baseball injuries per year involve the hip/groin and may lead to a significant amount of time spent on the disabled list. Injuries involving the hip and groin are relatively common in baseball players. Our knowledge of the mechanics of overhead throwing continues to evolve, as does our understanding of the contribution of power from the lower extremities and core. It is paramount that the team physician be able to accurately diagnose and treat injuries involving the hip/groin, as they may lead to significant disability and inability to return to elite levels of play. This review focuses on hip- and groin-related injuries in the baseball player, including femoroacetabular impingement, core muscle injury, and osteitis pubis.

  5. BODY POSTURES AND ASYMMETRIES IN FRONTAL AND TRANSVERSE PLANES IN THE TRUNK AREA IN TABLE TENNIS PLAYERS

    Katarzyna Barczyk-Pawelec

    2012-04-01

    Full Text Available The aim of this research was to assess the body posture within the trunk area in table tennis players and to estimate the correlations between the specific body posture types, their asymmetries and table tennis practice (training experience. To evaluate body posture the photogrammetric method based on the Moiré phenomenon with equipment by CQ Electronic was applied. Tests of significance of difference and correlation were used to estimate the correlation of the observed asymmetries with the training experience. 40 table tennis players and 43 subjects not practising sports participated in the research. The analysis of the results revealed that table tennis players, unlike non-players, are characterized by kyphotic body posture. It probably results from a specific trunk, head and limb position during table tennis matches. Thus, many asymmetries in frontal and transverse planes were observed in the examined table tennis players. Perhaps table tennis, which is characterized by intensive and one-sided trunk muscle work during its performance, is in favour of creating asymmetries. The majority of subjects did not reveal any statistically significant correlations between the observed body posture types, their asymmetries and training experience. However, it was observed that training experience is significantly related to the considerable asymmetry of the inclination angle of shoulder line (KLB. It may result from the negative influence of very intensive, one-sided work and constant work of the shoulder girdle muscles of the playing limb with negligence of exercises of the second limb.

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

    Jonathan Sargent

    2013-03-01

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

  7. Modificación en la composición corporal de jugadores de Hockey luego del período de preparación

    Perrice, Constanza

    2009-01-01

    El presente estudio tiene como objetivo determinar la relación entre el tipo de alimentación y el cambio en la composición corporal en jugadores de hockey sobre césped masculino que integran el Seleccionado Bonaerense de primera división, luego del período de preparación del año 2009 y si se ve influenciado por el grado de información en el campo de la nutrición deportiva. A través del mismo se establece la variación en el porcentaje de masa magra y masa grasa, mediante medi...

  8. Comparison of Angiotensin Converting Enzyme (ACE gene polymorphisms elite basketball players and volleyball players

    Emin Süel

    2015-09-01

    Full Text Available Aim: The purpose of this study is to research the differences of genotype polymorphism between the elite male and elite female basketball player, volleyball player and control group. Material and Methods: 58 basketball players (ages 24.25±4.99 years, height 188.22±12.31 cm and weight 80.62±16.34 kg, 64 volleyball players (ages 22.82±5.40 years, height 188.67±9.69 cm and weight 77.82±12.14 kg and 122 sedentary subjects (control group were participated randomly in the study. 5cc blood was taken control and control groups for measuring the ACE gene polymorphism. Chi-square and analysis of variance (ANOVA, Levene’s Tests, and frequencies of allele were used for statistical evaluation at significance level p0.05, basketball, volleyball and control group (p>0.05, male basketball, volleyball and control group (p>0.05, female basketball, volleyball and control group (p>0.05 and male and female athletes (p>0.05 respectively. There were no significance differences in male athletes between the genotype distribution and physical performance tests, such as 20m shuttle-run (F=1.31, vertical jump (F=0.22, and 20m sprint test (F=0.44. There were also no significance differences in female athletes between the genotype distribution and physical performance tests, such as 20m shuttle-run (F=2.03, vertical jump (F=0.10, and 20m sprint test (F=1.17. Conclusion: ACE polymorphism genotype distribution in terms of elite female and male volleyball players with elite female and male basketball players are the same.

  9. DOE handbook: Design considerations

    1999-04-01

    The Design Considerations Handbook includes information and suggestions for the design of systems typical to nuclear facilities, information specific to various types of special facilities, and information useful to various design disciplines. The handbook is presented in two parts. Part 1, which addresses design considerations, includes two sections. The first addresses the design of systems typically used in nuclear facilities to control radiation or radioactive materials. Specifically, this part addresses the design of confinement systems and radiation protection and effluent monitoring systems. The second section of Part 1 addresses the design of special facilities (i.e., specific types of nonreactor nuclear facilities). The specific design considerations provided in this section were developed from review of DOE 6430.1A and are supplemented with specific suggestions and considerations from designers with experience designing and operating such facilities. Part 2 of the Design Considerations Handbook describes good practices and design principles that should be considered in specific design disciplines, such as mechanical systems and electrical systems. These good practices are based on specific experiences in the design of nuclear facilities by design engineers with related experience. This part of the Design Considerations Handbook contains five sections, each of which applies to a particular engineering discipline

  10. DOE handbook: Design considerations

    NONE

    1999-04-01

    The Design Considerations Handbook includes information and suggestions for the design of systems typical to nuclear facilities, information specific to various types of special facilities, and information useful to various design disciplines. The handbook is presented in two parts. Part 1, which addresses design considerations, includes two sections. The first addresses the design of systems typically used in nuclear facilities to control radiation or radioactive materials. Specifically, this part addresses the design of confinement systems and radiation protection and effluent monitoring systems. The second section of Part 1 addresses the design of special facilities (i.e., specific types of nonreactor nuclear facilities). The specific design considerations provided in this section were developed from review of DOE 6430.1A and are supplemented with specific suggestions and considerations from designers with experience designing and operating such facilities. Part 2 of the Design Considerations Handbook describes good practices and design principles that should be considered in specific design disciplines, such as mechanical systems and electrical systems. These good practices are based on specific experiences in the design of nuclear facilities by design engineers with related experience. This part of the Design Considerations Handbook contains five sections, each of which applies to a particular engineering discipline.

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

    Deborah L. Feairheller

    2016-01-01

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

  12. How Players Lose Interest in Playing a Game

    Bauckhage, Christian; Kersting, Kristian; Sifa, Rafet

    2012-01-01

    introduce methods from random process theory into game data mining in order to draw inferences about player engagement. Given large samples (over 250,000 players) of behavioral telemetry data from five different action-adventure and shooter games, we extract information as to how long individual players......Analyzing telemetry data of player behavior in computer games is a topic of increasing interest for industry and research, alike. When applied to game telemetry data, pattern recognition and statistical analysis provide valuable business intelligence tools for game development. An important problem...... in this area is to characterize how player engagement in a game evolves over time. Reliable models are of pivotal interest since they allow for assessing the long-term success of game products and can provide estimates of how long players may be expected to keep actively playing a game. In this paper, we...

  13. Decreased shoulder function and pain common in recreational badminton players.

    Fahlström, M; Söderman, K

    2007-06-01

    The aim of this study was to describe the prevalence and consequences of painful conditions in the shoulder region in recreational badminton players. A questionnaire study was performed on 99 players, of whom 57 were also assessed with Constant score. Previous or present pain in the dominant shoulder was reported by 52% of the players. Sixteen percent of the players had on-going shoulder pain associated with badminton play. A majority of these players reported that their training habits were affected by the pain. Total Constant score was lower in the painful shoulders. Furthermore, range of active pain-free shoulder abduction was decreased. However, isometric shoulder strength test showed no differences when compared with pain-free shoulders. Even though the pain caused functional problems, the players were still playing with on-going symptoms. The diagnoses were mostly unknown, although history and clinical tests indicate problems resembling subacromial impingement.

  14. A Survey on Common Injuries in Recreational Badminton Players

    A Muttalib

    2009-11-01

    Full Text Available The aim of this descriptive study is to determine the incidence of injuries among recreational badminton players. We evaluated 86 recreational badminton players in the city of Malacca; 35 were excluded for fitting the exclusion criteria. The average recreational badminton player was 36.13 years old and had been playing badminton for the past 17.84 years at a frequency of 2.11 times per week. 39.21% of the recreational badminton players complained of recent injuries in relation to playing badminton. Our data showed that the most common injury sustained by recreational badminton players was pain and stiffness at the shoulder joint. None of the injuries sustained by the players in our data were serious enough to warrant any form of surgical intervention. We conclude that badminton is a sport of relatively low risk and that the majority of related injuries were chronic overuse injuries.

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

    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.

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

    Ito E; Iwamoto J; Azuma K; Matsumoto H

    2014-01-01

    Eri Ito, Jun Iwamoto, Koichiro Azuma, Hideo MatsumotoInstitute for Integrated Sports Medicine, Keio University School of Medicine, Tokyo, JapanAbstract: The purpose of the present study was to investigate sex-specific differences in injury types among basketball players. According to our database, during the 20-year period between October 1991 and June 2011, 1,219 basketball players (640 males and 579 females) consulted our sports medicine clinic; in total, 1,414 injuries in basketball player...

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

    Hale, Mallory

    2013-01-01

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

  18. Analyzing In-Game Movements of Soccer Players at Scale

    Gyarmati, Laszlo; Hefeeda, Mohamed

    2016-01-01

    It is challenging to get access to datasets related to the physical performance of soccer players. The teams consider such information highly confidential, especially if it covers in-game performance.Hence, most of the analysis and evaluation of the players' performance do not contain much information on the physical aspect of the game, creating a blindspot in performance analysis. We propose a novel method to solve this issue by deriving movement characteristics of soccer players. We use eve...

  19. Arthroscopic rotator cuff repair in elite rugby players

    Tambe, Amol; Badge, Ravi; Funk, Lennard

    2009-01-01

    Background: Rugby is an increasingly popular collision sport. A wide spectrum of injuries can be sustained during training and match play. Rotator cuff injury is uncommon in contact sports and there is little published literature on the treatment of rotator cuff tears in rugby players. Aims: We therefore reviewed the results and functional outcomes of arthroscopic rotator cuff repair in elite rugby players. Materials and Methods: Eleven professional rugby players underwent arthroscopic ...

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

    Barbero Álvarez, José Carlos; Gómez López, Maite; Barbero Álvarez, Verónica; Granda Vera, Juan; Castagna, Carlo

    2008-01-01

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

  1. Online Game Elements, Players and the Bond Between Them

    Schweizer, Sandra

    2017-01-01

    The results are guidelines for game developers to improve their game design. Through using the guidelines of the paper, developers know how to implement appealing online game elements which appeal to the player and draw them in. The result of the thesis are socializing, achievements and immersion are motivated the player to play online games, as well as the way online games stimulate the player's brain.

  2. Energy and macronutrient intakes of professional football (soccer) players.

    Maughan, R J

    1997-01-01

    OBJECTIVE: To examine the dietary habits of professional soccer players at two Scottish Premier League clubs during the competitive season. METHODS: A study of the dietary intake of 51 professional soccer players with two different clubs was carried out by the seven day weighed intake method. RESULTS: Physical characteristics of the two groups of players were similar, with only small differences in age and body mass but no difference in height and body fat. Mean (SD) daily energy intake for c...

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

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

    2011-01-01

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

  4. Exploring Stereotypical Perceptions of Female Players in Digital Gaming Contexts.

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

    2017-12-01

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

  5. A dynamic game of a transboundary pollutant with asymmetric players

    Martin, W.E.; Patrick, R.H.; Tolwinski, B.

    1993-01-01

    Modeling transboundary pollutants in a dynamic game framework provides a foundation for analyzing the impact of various policy options. The focus of this analysis is on the results of a tax/subsidy scheme used to address the transboundary problem of global climate change. A nonzero-sum dynamic game with asymmetric players is used to evaluate the policy impact of the tax/subsidy scheme on the respective player's value functions and strategies as determined by a Nash equilibrium feedback solution. The asymmetry of the players is reflected in their respective attitudes toward global climate change with one player benefiting from the change and the other losing. 17 refs., 5 tabs

  6. Profiling in basketball: physical and physiological characteristics of elite players.

    Ostojic, Sergej M; Mazic, Sanja; Dikic, Nenad

    2006-11-01

    The purpose of this study was to describe structural and functional characteristics of elite Serbian basketball players and to evaluate whether players in different positional roles have different physical and physiological profiles. Five men's basketball teams participated in the study and competed in the professional First National League. Physiological measurements were taken of 60 players during the final week of their preparatory training for competition. According to positional roles, players were categorized as guards (n = 20), forwards (n = 20), and centers (n = 20). Guards were older (p Vertical jump power was significantly higher in centers (p basketball.

  7. Head Impact Exposure in Junior and Adult Australian Football Players

    Mark Hecimovich

    2018-01-01

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

  8. Racism in soccer? Perception of challenges of black and white players by white referees, soccer players, and fans.

    Wagner-Egger, Pascal; Gygax, Pascal; Ribordy, Farfalla

    2012-02-01

    This experiment investigated challenge evaluations in soccer and their relation to prejudice: more precisely, whether skin colour may influence judgments of soccer tackles. Three groups of participants (soccer players, referees,and soccer fans) were asked to evaluate challenges, featuring Black and White players as aggressors and victims in a mixed-design study. Results showed that participants made some differentiations between Black and White players in a challenge evaluation task. Participants were more likely to consider within-group challenges as fouls and were faster to consider challenges made by Black players as fouls. On the other hand, fouls made by White players were seen as more severe. There were no major differences between the participating groups, suggesting that the observed effects were independent of how good players were or whether the participants were referees or not.

  9. Making star teams out of star players.

    Mankins, Michael; Bird, Alan; Root, James

    2013-01-01

    Top talent is an invaluable asset: In highly specialized or creative work, for instance, "A" players are likely to be six times as productive as "B" players. So when your company has a crucial strategic project, why not multiply all that firepower and have a team of your best performers tackle it? Yet many companies hesitate to do this, believing that all-star teams don't work: Big egos will get in the way. The stars won't be able to work with one another. They'll drive the team Leader crazy. Mankins, Bird, and Root of Bain & Company believe it's time to set aside that thinking. They have seen all-star teams do extraordinary work. But there is a right way and a wrong way to organize them. Before you can even begin to assemble such a team, you need to have the right talent management practices, so you hire and develop the best people and know what they're capable of. You have to give the team appropriate incentives and leaders and support staffers who are stars in their own right. And projects that are ill-defined or small scale are not for all-star teams. Use them only for critical missions, and make sure their objectives are clear. Even with the right setup, things can still go wrong. The wise executive will take steps to manage egos, prune non-team-players, and prevent average coworkers from feeling completely undervalued. She will also invest a lot of time in choosing the right team Leader and will ask members for lots of feedback to monitor how that leader is doing.

  10. Does ovulation affect performance in tennis players?

    Otaka, Machiko; Chen, Shu-Man; Zhu, Yong; Tsai, Yung-Shen; Tseng, Ching-Yu; Fogt, Donovan L; Lim, Boon-Hooi; Huang, Chih-Yang; Kuo, Chia-Hua

    2018-01-01

    Scientific data on the performance of collegiate female tennis players during the menstrual phases are scarce. Double-blind, counter-balanced, crossover trials were conducted to examine whether tennis performance was affected during menstruation, with and without dehydroepiandrosterone sulfate (DHEA-S) supplementation. Ten Division 1 collegiate tennis players (aged 18-22 years) were evenly assigned into placebo-supplemented and DHEA-supplemented (25 mg/day) trials. Treatments were exchanged among the participants after a 28-day washout. Tennis serve performance was assessed on the first day of menstrual bleeding (day 0/28) and on days 7, 14 and 21. Mood state was unaltered during the menstrual cycles in both trials. The lowest tennis serve performance score (speed times accuracy) occurred on day 14 (P=0.06 vs day 0; P=0.01 vs day 21) in both placebo and DHEA trials. Decreased performance on day 14 was explained by decreased accuracy (P=0.03 vs day 0/28; P=0.01 vs day 21), but not velocity itself. Isometric hip strength, but not quadriceps strength, was moderately lower on day 14 (P=0.08). Increasing plasma DHEA-S (by ~65%) during the DHEA-supplemented trial had no effects on mood state, sleep quality or tennis serve performance. We have shown that menses does not affect serve performance of collegiate tennis players. However, the observed decrement in the accuracy of serve speed near ovulation warrants further investigation.

  11. The Importance of Vitaminsfor Soccer Players.

    Eskici, Günay

    2015-12-01

    Soccer is one of the most widely played and complex sports in the world, where success depends on technical, tactical and physical skills of the players. Studies to improve performance in soccer have often focused on technique and tactics. However, nutrition is one of the most important factors influencing athletic performance of the players. The duration of matches is long and the training is intense. This leads to increased requirements for energy and nutrients, as well as increased reactive oxygen radicals and hence increased muscle damage. Vitamins are micronutrients that a living organism requires in trace quantities for health. As these assume crucial functions in the body, the performance of the player is negatively affected particularly during long-term deficiency. Beta-carotene, C and E vitamins are antioxidants that protect against oxygen radicals. In case of their deficiency, oxidative stress and muscle fatigue increases. Vitamin D is involved in maintaining mineral balance, and it increases absorption of dietary calcium and phosphorus. In case of vitamin D deficiency, injuries resulting from the musculoskeletal system might increase. B Vitamins (B1, B2, niacin, B6, B12, biotin, folic acid and pantothenic acid) perform duties such as energy production, absorption and transport of iron and blood cell production. Athletes who follow an energy-restricted and imbalanced diet might develop vitamin deficiency. In such a case, supplements can be used as recommended by the doctor/dietician. It is further reported that supplement use by athletes who have an adequate and balanced nutrition does not increase performance.

  12. Payoff Shares in Two-Player Contests

    Samuel Häfner

    2016-09-01

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

  13. [International cooperation on aging: areas and players].

    Sidorenko, A V; Mikhaĭlova, O N

    2014-01-01

    This review article is devoted to the issues of international cooperation on ageing. It aims at describing the basic areas of cooperation and introducing its major players. Within the limited length of a journal article it is hardly possible to offer an exhaustive presentation of all available information; thus the article strives to provide a general orientation within the selected themes. The authors are hopeful that the presented materials will be of interest to the policy oriented researchers, policy makers and professionals working in the field of ageing and related areas such as social security, health and social services etc., as well as to the activists of non-governmental organizations.

  14. Intermittent claudication in a professional rugby player.

    Bray, A E; Lewis, W A

    1992-04-01

    Intermittent claudication in a professional rugby player is described. The typical features of a delayed and difficult diagnosis of an external iliac artery stenosis were found. The noninvasive diagnostic protocol used to investigate this young patient with a minimal arterial lesion enabled accurate localization and angioplasty to be performed at the same time as diagnostic angiography. The patient was symptom free with normal arterial pressures on follow-up. It is suggested that appropriate noninvasive investigations should be performed before angiography in young people with minimal lesions.

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

    Franja Fratrić

    2009-11-01

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

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

    Wong Zhen Feng

    2017-06-01

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

  17. Comparative characteristics of psychophysiological features skilled basketball players-women with hearing and skilled basketball players healthy

    Kozina Zh.L.

    2013-06-01

    Full Text Available A comparative analysis of the psychophysiological features of skilled basketball players with normal hearing and impaired hearing aid. The study involved two women's basketball team to 12 people each. The study used a complex computer psychodiagnosis. The complex includes 20 psychophysiological and 18 personal psychological tests. The indicators of the time simple and complex reaction and average tapping test healthy skilled basketball players and basketball players are hearing impaired. There was a significant higher rates of visual-motor speed and reaction-tapping test in basketball players with hearing compared to healthy athletes. This is explained by compensatory mechanisms that occur in connection with the violation of the audition.

  18. Comparative characteristics of psychophysiological features skilled basketball players-women with hearing and skilled basketball players healthy

    Zh.L. Kozina

    2013-07-01

    Full Text Available A comparative analysis of the psychophysiological features of skilled basketball players with normal hearing and impaired hearing aid. The study involved two women's basketball team to 12 people each. The study used a complex computer psychodiagnosis. The complex includes 20 psychophysiological and 18 personal psychological tests. The indicators of the time simple and complex reaction and average tapping test healthy skilled basketball players and basketball players are hearing impaired. There was a significant higher rates of visual-motor speed and reaction-tapping test in basketball players with hearing compared to healthy athletes. This is explained by compensatory mechanisms that occur in connection with the violation of the audition.

  19. ANALYSIS AND COMPARISON OF ADOLESCENT ATHLETES' MOTIVATION: BASKETBALL PLAYERS VS. FOOTBALL PLAYERS

    Bartolom\\u00E9 J. Almagro

    2009-01-01

    Full Text Available The motivation of an athlete is determinant for the athletic engagement of the adolescent. The present study attempts to analyze the motivation of adolescent basketball and football players from the perspectives of Achievement Goal Theory (Nicholls, 1989 and Self-Determination Theory (Deci & Ryan, 1985. The study's sample was composed of 248 athletes from 12 to 17 years of age. Half were from basketball and half were from football. The instruments that were utilized were: the Spanish version of the Sport Motivation Scale (SMS (Núñez, Martín-Albo, Navarro, & González, 2006, the Spanish version of the Perceived Motivational Climate in Sport Questionnaire-2 (PMSCQ-2 (Balaguer, Mayo, Atienza, & Duda, 1997, and the adapted Spanish translation (Moreno, Moreno, & Cervelló, 2007 of the Intention to be Physically Active Scale (IPAS by Hein, Müür, and Koka (2004. The comparison of the means of the variables between football and basketball players was done utilizing the student t-test for independent samples. Significant differences were found for variables such as: intrinsic motivation (IM toward accomplishment, external regulation, amotivation, task, ego, and Self-Determination Index (SDI. Basketball players obtained higher values in the SDI, in task, and in IM toward accomplishment than football players. The search for premature performance in football and coaches' educations can help to explain these differences. The importance of these differences reside in the relationship between these motivational variables and the adherence to athletic practice. In conclusion, basketball demonstrated better values in motivational variables, which demonstrates that training sessions are more oriented toward task than ego, that players have more intrinsic and self-determined motivation, and therefore, the adherence of the young athletes will be greater in this sport.

  20. Has player development in men's tennis really changed? An historical rankings perspective.

    Bane, Michael Kenneth; Reid, Machar; Morgan, Stuart

    2014-01-01

    Tennis federations are regularly faced with decisions regarding which athletes should be supported in financial terms, and for how long. The financial investments can be considerable, given the cost of competing on tour has been estimated at a minimum $121,000 per year and only the top 130 professionally ranked athletes earned enough prize money to cover this cost in 2012. This study investigates key points of progression in tennis players' careers, to determine how these have changed over time and how that evolution may inform talent development. Approximately 400,000 weekly rankings for 273 male professional tennis players between 1985 and 2010 were compiled, and historical trends in the time taken to reach career milestones were investigated by least-squares regression. The time between earning a first professional ranking point and entry into the Top 100 significantly increased over time for all considered athletes. This was at the detriment of time spent within the Top 100 for some athletes. Career peak Top 50-100 athletes have shown an increase in longevity. These results assist tennis federations in assessing the progress of developing athletes and highlight the evolving nature of the competition for top players.

  1. Factors That Influence Running Intensity in Interchange Players in Professional Rugby League.

    Delaney, Jace A; Thornton, Heidi R; Duthie, Grant M; Dascombe, Ben J

    2016-11-01

    Rugby league coaches adopt replacement strategies for their interchange players to maximize running intensity; however, it is important to understand the factors that may influence match performance. To assess the independent factors affecting running intensity sustained by interchange players during professional rugby league. Global positioning system (GPS) data were collected from all interchanged players (starters and nonstarters) in a professional rugby league squad across 24 matches of a National Rugby League season. A multilevel mixed-model approach was employed to establish the effect of various technical (attacking and defensive involvements), temporal (bout duration, time in possession, etc), and situational (season phase, recovery cycle, etc) factors on the relative distance covered and average metabolic power (P met ) during competition. Significant effects were standardized using correlation coefficients, and the likelihood of the effect was described using magnitude-based inferences. Superior intermittent running ability resulted in very likely large increases in both relative distance and P met . As the length of a bout increased, both measures of running intensity exhibited a small decrease. There were at least likely small increases in running intensity for matches played after short recovery cycles and against strong opposition. During a bout, the number of collision-based involvements increased running intensity, whereas time in possession and ball time out of play decreased demands. These data demonstrate a complex interaction of individual- and match-based factors that require consideration when developing interchange strategies, and the manipulation of training loads during shorter recovery periods and against stronger opponents may be beneficial.

  2. Caffeine-containing energy drink improves physical performance of elite rugby players during a simulated match.

    Del Coso, Juan; Ramírez, Juan A; Muñoz, Gloria; Portillo, Javier; Gonzalez-Millán, Cristina; Muñoz, Víctor; Barbero-Álvarez, José C; Muñoz-Guerra, Jesús

    2013-04-01

    The purpose of this study was to investigate the effectiveness of a caffeine-containing energy drink in enhancing rugby players' physical performance during a simulated match. A second purpose was to determine the urinary caffeine excretion derived from the energy drink intake. In a randomized and counterbalanced order, 26 elite rugby players (mean ± SD for age and body mass, 25 ± 2 y and 93 ± 15 kg) played 2 simulated rugby games (2 × 30 min) 60 min after ingesting (i) 3 mg of caffeine per kilogram of body mass in the form of an energy drink (Fure, ProEnergetics) or (ii) the same drink without caffeine (placebo). During the matches, the individual running distance and the instantaneous speed were measured, and the number of running actions above 20 km·h(-1) (i.e., sprints) were determined, using global positioning system devices. The number of impacts above 5 g during the matches was determined by accelerometry. The ingestion of the energy drink, compared with the placebo, increased the total distance covered during the match (4749 ± 589 vs 5139 ± 475 m, p caffeine concentration (0.1 ± 0.1 vs 2.4 ± 0.9 μg·mL(-1), p caffeine dose equivalent to 3 mg·kg(-1) considerably enhanced the movement patterns of rugby players during a simulated match.

  3. Unseen players shape benthic competition on coral reefs.

    Barott, Katie L; Rohwer, Forest L

    2012-12-01

    Recent work has shown that hydrophilic and hydrophobic organic matter (OM) from algae disrupts the function of the coral holobiont and promotes the invasion of opportunistic pathogens, leading to coral morbidity and mortality. Here we refer to these dynamics as the (3)DAM [dissolved organic matter (DOM), direct contact, disease, algae and microbes] model. There is considerable complexity in coral-algae interactions; turf algae and macroalgae promote heterotrophic microbial overgrowth of coral, macroalgae also directly harm the corals via hydrophobic OM, whereas crustose coralline algae generally encourage benign microbial communities. In addition, complex flow patterns transport OM and pathogens from algae to downstream corals, and direct algal contact enhances their delivery. These invisible players (microbes, viruses, and OM) are important drivers of coral reefs because they have non-linear responses to disturbances and are the first to change in response to perturbations, providing near real-time trajectories for a coral reef, a vital metric for conservation and restoration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Altered resting brain function and structure in professional badminton players.

    Di, Xin; Zhu, Senhua; Jin, Hua; Wang, Pin; Ye, Zhuoer; Zhou, Ke; Zhuo, Yan; Rao, Hengyi

    2012-01-01

    Neuroimaging studies of professional athletic or musical training have demonstrated considerable practice-dependent plasticity in various brain structures, which may reflect distinct training demands. In the present study, structural and functional brain alterations were examined in professional badminton players and compared with healthy controls using magnetic resonance imaging (MRI) and resting-state functional MRI. Gray matter concentration (GMC) was assessed using voxel-based morphometry (VBM), and resting-brain functions were measured by amplitude of low-frequency fluctuation (ALFF) and seed-based functional connectivity. Results showed that the athlete group had greater GMC and ALFF in the right and medial cerebellar regions, respectively. The athlete group also demonstrated smaller ALFF in the left superior parietal lobule and altered functional connectivity between the left superior parietal and frontal regions. These findings indicate that badminton expertise is associated with not only plastic structural changes in terms of enlarged gray matter density in the cerebellum, but also functional alterations in fronto-parietal connectivity. Such structural and functional alterations may reflect specific experiences of badminton training and practice, including high-capacity visuo-spatial processing and hand-eye coordination in addition to refined motor skills.

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

    Ito, Eri; Iwamoto, Jun; Azuma, Koichiro; Matsumoto, Hideo

    2015-01-01

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

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

    Ito E

    2014-12-01

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

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

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

    2014-01-01

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

  8. N-player quantum games in an EPR setting.

    James M Chappell

    Full Text Available The N-player quantum games are analyzed that use an Einstein-Podolsky-Rosen (EPR experiment, as the underlying physical setup. In this setup, a player's strategies are not unitary transformations as in alternate quantum game-theoretic frameworks, but a classical choice between two directions along which spin or polarization measurements are made. The players' strategies thus remain identical to their strategies in the mixed-strategy version of the classical game. In the EPR setting the quantum game reduces itself to the corresponding classical game when the shared quantum state reaches zero entanglement. We find the relations for the probability distribution for N-qubit GHZ and W-type states, subject to general measurement directions, from which the expressions for the players' payoffs and mixed Nash equilibrium are determined. Players' N x N payoff matrices are then defined using linear functions so that common two-player games can be easily extended to the N-player case and permit analytic expressions for the Nash equilibrium. As a specific example, we solve the Prisoners' Dilemma game for general N ≥ 2. We find a new property for the game that for an even number of players the payoffs at the Nash equilibrium are equal, whereas for an odd number of players the cooperating players receive higher payoffs. By dispensing with the standard unitary transformations on state vectors in Hilbert space and using instead rotors and multivectors, based on Clifford's geometric algebra (GA, it is shown how the N-player case becomes tractable. The new mathematical approach presented here has wide implications in the areas of quantum information and quantum complexity, as it opens up a powerful way to tractably analyze N-partite qubit interactions.

  9. Leadership power perception of amateur and professional soccer coaches and players according to their belief in good luck or not.

    Konter, Erkut

    2010-09-01

    The purpose of this study was to analyze the leadership power perception of amateur and professional soccer coaches and players according to their belief in good luck or not. Data collected from 165 male soccer coaches and 870 male soccer players including professionals and amateurs. The coaches had a mean age of 40.24 years (SD = 8.40) and had been coaching for an average of 8.56 years (SD = 6.75). The players had a mean age of 18.40 years (SD = 4.00) and had been playing soccer for an average of 6.00 years (SD = 4.15) with license. Adapted Turkish version of Power in Soccer Questionnaire-Other (PSQ-O for soccer players), Power in Soccer Questionnaire-Self (PSQ-S for coaches) and an information form were used for the data collection. Cronbach Reliability Alphas of PSQ-O and PSQ-S range between 0.60 and 0.84. Players' and coaches' data were analyzed by Kruskal-Wallis and Mann Whitney Tests. Analysis of PSQ-O revealed significant differences related to Coersive Power-CP [chi2 (3) = 8.46, p Referent Power-RP [chi2 (3) = 14.84, p 0.05). Results of PSQ-O and PSQ-S indicated complex relationships related to belief in good luck or not. Overall, there are differences between coaches' and players'perception of CP, LP and EP related to belief in good luck or not. The only similarity appears to be in perception of RP. However, there is lack of research to make more certain conclusions. Future researchers should also take into consideration gender, sport experience, age, taking responsibility, self-confidence, attributions, expectations, superstitions, emotions, perception of achievement etc.

  10. Sport commitment in adolescent soccer players

    Noelia Belando Pedreño

    2016-03-01

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

  11. Somatotype and performance in female futsal players

    Marcos Roberto Queiroga

    2008-07-01

    Full Text Available http://dx.doi.org/10.5007/1980-0037.2008v10n1p56 The present study aimed to verify whether body somatotype was indicative of competitive success in female utsal (indoor soccer players. One hundred and twelve players (22.1 ± 5.4 years; 58.4 ± 6.9 kg; 161.8 ± 6.2 cm, from ten teams and seven different states, had participated in a national competition. The anthropometric date was analyzed using one-way ANOVA for repeated measures. The somatotype dispersion distance was applied to compare somatotypes between the champion team (reference and the other teams (from 2nd to 10th position. Anthropometric characteristics did not differ signifi cantly among teams. The results showed that the endomorphic component was predominant in relation to the mesomorphic and ectomorphic component, irrespective of a team’s ranking at the end of the competition. Therefore, the body somatotypes of female futsal teams cannot be considered as indicative of their competitive success.

  12. Scapula Kinematics of Youth Baseball Players

    Oliver Gretchen

    2015-12-01

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

  13. Badminton injuries in youth competitive players.

    Goh, S L; Mokhtar, A H; Mohamad Ali, M R

    2013-02-01

    The aim of the study was to examine sports injury pattern and establish cost of injuries in relation to training of 58 competitive badminton players in a Malaysian National Sports School. This one-year prospective observational study recruited all the 13-16 year old students after obtaining informed consent from their appointed guardian. All participants were requested to report any injuries, which were pain or disabilities that occur within the study period (September 1, 2008 to August 31, 2009) either during training or competition. Injured students were to seek treatment from the researcher(s) who made weekly visits and they were then followed up accordingly until they return to full training. Details and progress of the injuries were documented during each visit. Sixty-three injuries were recorded. Soft tissue sprains/strains were the commonest injury (64%). About one third of the injuries occurred in the lower limb especially the knees and was followed by back injuries; 38% of the injuries did not require training modification, half of these injuries resumed training within one week. Upon full training, half of them were still symptomatic. Injury risk was 57%; injury rate was 0.9 injuries/ player/1000 training hours. Badminton injuries mostly involved the lower limb and almost all overuse injuries occurred in the lower limb. However, badminton injuries as a whole were predominantly sprains and strains, and not overuse in nature as widely believed.

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

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

    2015-01-01

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

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

    Following the formation of a single body to govern rugby in South. Africa in 1992, the ... Players from across the country were identified and invited to various ... different levels of rugby cannot be evaluated because the players representing ..... programmes for youth and young adults is the disparity in body size and fitness of ...

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

    te Wierike, Simon; Lemmink, Koen; de Jong, M.C.; Tromp, E.J.; Vuijk, P.J.; Malina, R.M.; Elferink-Gemser, Marije; Visscher, Chris

    2013-01-01

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

  17. Physical fitness of elite female Rugby Union players | Hene | African ...

    Rugby union is a contact sport in which players require high levels of physical fitness, which is a composite of aerobic and anaerobic endurance, muscle strength and power, speed, agility and body composition. The aim of this study was to assess the physical fitness characteristics of elite female rugby union players.

  18. Physical and physiological profiles of Boland netball players | Venter ...

    The netball players were assessed for flexibility, speed, agility, power and aerobic endurance. Anthropometrical measurements were also taken. Descriptive statistics were calculated, after which Student s unpaired t-tests were used to compare results between the Boland and Australian under-21 netball players. Results.

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

    Wallace, Michael

    1988-01-01

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

  20. Player Collaboration in the Explorative Sound Environment ToneInk

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

    2016-01-01

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

  1. N-Player Stochastic Differential Games. [control theory

    Varaiya, P.

    1974-01-01

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

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

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

    2010-03-01

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

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

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

    2011-01-01

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

  4. Fitness profile of elite junior South African badminton players | van ...

    The purpose of this study was to establish the fitness profile of the elite junior badminton players in South Africa through the measurement and description of their body composition, aerobic power, muscular characteristics, speed, flexibility and agility. Eight elite male and seven elite female badminton players between the ...

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

    ... in prospective studies at the same schools. The players' knowledge of techniques known to prevent rugby injuries was inadequate and too little attention was paid at the start of the rugby season to training and coaching techniques to reduce injury risk. Coaching errors may therefore have predisposed players to injury.

  6. Detection of player learning curve in a car driving game

    Bontchev, Boyan; Vassileva, Dessislava

    2018-01-01

    Detection of learning curves of player metrics is very important for the serious (or so called applied) games, because it provides an indicator representing how players master the game tasks by acquiring cognitive abilities, knowledge, and necessary skills for solving the game challenges. Real

  7. Optimal development of rugby players: a case study | Rainsford ...

    An empirical study was conducted among 40 contracted Vodacom players from the Golden Lions Rugby Union who completed structured questionnaires prior to a physical testing. The majority of players were between 19 and 31 years. Ninety percent belonged to the white population group and 10% identified themselves ...

  8. Analysis of Bridge Player Profiles According to Their Intelligence Areas

    Bilir, Fatma Pervin; Sirin, Yeliz

    2017-01-01

    The aim of this study is to figure out profiles of bridge players and analyzing them according to their intelligence areas. The sample of the study is consist of 100 volunteers out of 200 bridge players who have attended "Çukurova open double bridge championship" in Adana, Turkey at February 2016. Data have been collected via…

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

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

    2013-01-01

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

  10. Little League Baseball and Players' Self-Esteem.

    Hawkins, Donna B.; Gruber, Joseph J.

    1982-01-01

    The effect of a season of little league baseball on the self-esteem of 94 pre-adolescent players was investigated. The Coopersmith Self-esteem Inventory and a newly devised Baseball-Self scale were administered. Significant improvements in players' total Self-esteem, Home-Parents and School-Academic scores were found. (Author/PN)

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

    Hubacek, Pavel; Park, Sunoo

    2014-01-01

    In this work we apply methods from cryptography to enable mutually distrusting players to implement broad classes of mediated equilibria of strategic games without trusted mediation. Our implementation uses a pre-play 'cheap talk' phase, consisting of non- binding communication between players...

  12. Translucent Players: Explaining Cooperative Behavior in Social Dilemmas

    Valerio Capraro

    2016-06-01

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

  13. Identification of Factors Determining Market Value of the Most Valuable Football Players

    Sebastian Majewski

    2016-03-01

    Full Text Available Purpose: The problem of identifying the most important determinants of the market value of football players is quite well described in the literature. There are many works that try to identify these factors. Some of them are focused on variables to make a set complete and others are on models and methods. The aim of this article is to present the variables influencing the valuation and to build an econometric model valuing footballers playing on the forward position, taking into consideration the assumptions of the econometric modelling. Such an approach indicates managers as other sources for obtaining information. Methodology: Econometric models were used to verify the hypothesis formulated in this research. The database was created on the basis of variables presented on the website www.transfermarkt. de that presents the values of the most valuable football players in the world playing on the forward position. The Gretl program was used in the research. Findings: The literature review showed that there are many independent variables having an impact on the value of the player. There are also many different models used to valuate footballers’ performance rights. The results of estimation of models in the research indicated that such factors as Canadian classification points adjusted the market value of the team and dummy variables describing “goodwill” (only for the best players had an impact on the market value of footballers’ performance rights. Limitations/implications: Information about different factors having an impact on football players’ market value could support the investment decision process of football managers. Originality/value: The results were part of a study concerning economics of sport, particularly processes of management of football clubs and valuation of intangible assets.

  14. Hamstring muscle strains in professional football players: a 10-year review.

    Elliott, Marcus C C W; Zarins, Bertram; Powell, John W; Kenyon, Charles D

    2011-04-01

    Investigations into hamstring strain injuries at the elite level exist in sports such as Australian Rules football, rugby, and soccer, but no large-scale study exists on the incidence and circumstances surrounding these injuries in the National Football League (NFL). Injury rates will vary between different player positions, times in the season, and across different playing situations. Descriptive epidemiology study. Between 1989 and 1998, injury data were prospectively collected by athletic trainers for every NFL team and recorded in the NFL's Injury Surveillance System. Data collected included team, date of injury, activity the player was engaged in at the time of injury, injury severity, position played, mechanism of injury, and history of previous injury. Injury rates were reported in injuries per athlete-exposure (A-E). An athlete-exposure was defined as 1 athlete participating in either 1 practice or 1 game. Over the 10-year study period 1716 hamstring strains were reported for an injury rate (IR) of 0.77 per 1000 A-E. More than half (51.3%) of hamstring strains occurred during the 7-week preseason. The preseason practice IR was significantly elevated compared with the regular-season practice IR (0.82/1000 A-E and 0.18/1000 A-E, respectively). The most commonly injured positions were the defensive secondary, accounting for 23.1% of the injuries; the wide receivers, accounting for 20.8%; and special teams, constituting 13.0% of the injuries in the study. Hamstring strains are a considerable cause of disability in football, with the majority of injuries occurring during the short preseason. In particular, the speed position players, such as the wide receivers and defensive secondary, as well as players on the special teams units, are at elevated risk for injury. These positions and situations with a higher risk of injury provide foci for preventative interventions.

  15. Return to sport after surgical treatment for pubalgia among professional soccer players.

    de Queiroz, Roberto Dantas; de Carvalho, Rogério Teixeira; de Queiroz Szeles, Paulo Roberto; Janovsky, César; Cohen, Moisés

    2014-01-01

    to evaluate the return to sport after surgical treatment for pubalgia among 30 professional soccer players and describe the surgical technique used. this case series was evaluated by means of a questionnaire and physical examination on 30 male professional soccer players of mean age 24.4 years (range: 18-30). The mean duration of the symptoms was 18.6 months (range: 13-28). The diagnosis was made through clinical investigation, special maneuvers and complementary examinations, by the same examiner. All the patients underwent surgical treatment after conservative treatment failed; all procedures were performed by the same surgeon using the same technique. Nonparametric comparisons were made to investigate the time taken to recover after the surgery, for the patients to return to their sport. five patients evolved with hematoma, with the need to remove the stitches three weeks after the operation because of a small dehiscence at the site of the operative wound. The wound healed completely in all these cases by five weeks after the surgery. Four patients presented dysuria in the first week, but improved in the second postoperative week. The mean time taken to return to training was around eight weeks (range: seven-nine). All the players returned to competitive soccer practice within 16 weeks. When asked about their degree of satisfaction after the operation (satisfied or dissatisfied), taking into consideration their return to the sport, there was 100% satisfaction, and they returned to professional practice at the same competitive level as before the injury. This degree of satisfaction continued to the last assessment, which was made after 36 months of postoperative follow-up. the surgical technique presented in this case series, with trapezoidal resection of the pubic symphysis in association with bilateral partial tenotomy of the long adductor, was a fast and effective procedure with a low rate of postoperative complications. It was shown to be an excellent

  16. Female Chess Players Outperform Expectations When Playing Men.

    Stafford, Tom

    2018-03-01

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

  17. Generative Agents for Player Decision Modeling in Games

    Holmgård, Christoffer; Liapis, Antonios; Togelius, Julian

    2014-01-01

    This paper presents a method for modeling player decision making through the use of agents as AI-driven personas. The paper argues that artificial agents, as generative player models, have properties that allow them to be used as psyhometrically valid, abstract simulations of a human player......’s internal decision making processes. Such agents can then be used to interpret human decision making, as personas and playtesting tools in the game design process, as baselines for adapting agents to mimic classes of human players, or as believable, human-like opponents. This argument is explored...... in a crowdsourced decision making experiment, in which the decisions of human players are recorded in a small-scale dungeon themed puzzle game. Human decisions are compared to the decisions of a number of a priori defined “archetypical” agent-personas, and the humans are characterized by their likeness...

  18. Evaluating and treating neurobehavioral symptoms in professional American football players

    Possin, Katherine L.; Hess, Christopher P.; Huang, Eric J.; Grinberg, Lea T.; Nolan, Amber L.; Cohn-Sheehy, Brendan I.; Ghosh, Pia M.; Lanata, Serggio; Merrilees, Jennifer; Kramer, Joel H.; Berger, Mitchel S.; Miller, Bruce L.; Yaffe, Kristine; Rabinovici, Gil D.

    2015-01-01

    Summary In the aftermath of multiple high-profile cases of chronic traumatic encephalopathy (CTE) in professional American football players, physicians in clinical practice are likely to face an increasing number of retired football players seeking evaluation for chronic neurobehavioral symptoms. Guidelines for the evaluation and treatment of these patients are sparse. Clinical criteria for a diagnosis of CTE are under development. The contribution of CTE vs other neuropathologies to neurobehavioral symptoms in these players remains unclear. Here we describe the experience of our academic memory clinic in evaluating and treating a series of 14 self-referred symptomatic players. Our aim is to raise awareness in the neurology community regarding the different clinical phenotypes, idiosyncratic but potentially treatable symptoms, and the spectrum of underlying neuropathologies in these players. PMID:26336629

  19. Entrepreneurship: Some Considerations

    V. Martinho

    2016-02-01

    Full Text Available In this work it is presented some considerations about entrepreneurship. Most of these questions are linked with Portuguese context. Portugal has some particularities, namely because the asymmetries between the littoral and the interior. This situation carried out some problems that complicate and prevent the appearance of new innovated business. In a situation of crisis like that we have today this context can become a really problem to solve some questions.

  20. Fusion facility siting considerations

    Bussell, G.T.

    1985-01-01

    Inherent in the fusion program's transition from hydrogen devices to commercial power machines is a general increase in the size and scope of succeeding projects. This growth will lead to increased emphasis on safety, environmental impact, and the external effects of fusion in general, and of each new device in particular. A critically important consideration in this regard is site selection. The purpose of this paper is to examine major siting issues that may affect the economics, safety, and environmental impact of fusion

  1. Storage array reflection considerations

    Haire, M.J.; Jordan, W.C.; Taylor, R.G.

    1997-01-01

    The assumptions used for reflection conditions of single containers are fairly well established and consistently applied throughout the industry in nuclear criticality safety evaluations. Containers are usually considered to be either fully water reflected (i.e., surrounded by 6 to 12 in. of water) for safety calculations or reflected by 1 in. of water for nominal (structural material and air) conditions. Tables and figures are usually available for performing comparative evaluations of containers under various loading conditions. Reflection considerations used for evaluating the safety of storage arrays of fissile material are not as well established. When evaluating arrays, it has become more common for analysts to use calculations to demonstrate the safety of the array configuration. In performing these calculations, the analyst has considerable freedom concerning the assumptions made for modeling the reflection of the array. Considerations are given for the physical layout of the array with little or no discussion (or demonstration) of what conditions are bounded by the assumed reflection conditions. For example, an array may be generically evaluated by placing it in a corner of a room in which the opposing walls are far away. Typically, it is believed that complete flooding of the room is incredible, so the array is evaluated for various levels of water mist interspersed among array containers. This paper discusses some assumptions that are made regarding storage array reflection

  2. Effect of Concussion on Performance of National Football League Players.

    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.

  3. Incidence of injuries in high school softball and baseball players.

    Shanley, Ellen; Rauh, Mitchell J; Michener, Lori A; Ellenbecker, Todd S

    2011-01-01

    Participation in high school sports has grown 16.1% over the last decade, but few studies have compared the overall injury risks in girls' softball and boys' baseball. To examine the incidence of injury in high school softball and baseball players. Cohort study. Greenville, South Carolina, high schools. Softball and baseball players (n = 247) from 11 high schools. Injury rates, locations, types; initial or subsequent injury; practice or game setting; positions played; seasonal trends. The overall incidence injury rate was 4.5/1000 athlete-exposures (AEs), with more injuries overall in softball players (5.6/1000 AEs) than in baseball players (4.0/1000 AEs). Baseball players had a higher initial injury rate (75.9/1000 AEs) than softball players (66.4/1000 AEs): rate ratio (RR) = 0.88, 95% confidence interval (CI) = 0.4, 1.7. The initial injury rate was higher than the subsequent injury rate for the overall sample (P softball (P Softball players were more likely to be injured in a game than were baseball players (RR = 1.92, 95% CI = 0.8, 4.3). Most injuries (77%) were mild (3.5/1000 AEs). The upper extremity accounted for the highest proportion of injuries (63.3%). The incidence of injury for pitchers was 37.3% and for position players was 15.3%. The rate of injury was highest during the first month of the season (7.96/1000 AEs). The incidence of injury was low for both softball and baseball. Most injuries were minor and affected the upper extremity. The injury rates were highest in the first month of the season, so prevention strategies should be focused on minimizing injuries and monitoring players early in the season.

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

    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.

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

    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.

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

    Brian Skinner

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

  7. Relative age effect and the re-selection of Danish male handball players for national teams

    Wrang, Christian Meedom; Rossing, Niels Nygaard; Lilholt, Rasmus Mølgaard

    2018-01-01

    The relationship between date of birth and expertise in various sports is well established, and known as the relative age effect (RAE). However, new results in e.g. Canadian Hockey (Gibbs et al., 2012) and British cricket and rugby (McCarthy & Collins, 2014; McCarthy, Collins, & Court, 2015) have...

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

    Kevser Ermin

    2012-01-01

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

  9. Invisible players: a family systems model.

    Hellstedt, Jon

    2005-10-01

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

  10. Morphological classification of novice female volleyball players

    José António Ribeiro Maia

    2003-12-01

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

  11. Gamification in Fostering Creativity: Player Type Approach

    Marius Kalinauskas

    2015-02-01

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

  12. Iliopsoas and Gluteal Muscles Are Asymmetric in Tennis Players but Not in Soccer Players

    Sanchis-Moysi, Joaquin; Idoate, Fernando; Izquierdo, Mikel; Calbet, Jose A. L.; Dorado, Cecilia

    2011-01-01

    Purpose To determine the volume and degree of asymmetry of iliopsoas (IL) and gluteal muscles (GL) in tennis and soccer players. Methods IL and GL volumes were determined using magnetic resonance imaging (MRI) in male professional tennis (TP) and soccer players (SP), and in non-active control subjects (CG) (n = 8, 15 and 6, respectively). Results The dominant and non-dominant IL were hypertrophied in TP (24 and 36%, respectively, Psoccer players had similar volumes in both sides (P = 0.87). The degree of side-to-side asymmetry decreased linearly from the first lumbar disc to the pubic symphysis in TP (r = −0.97, PSoccer and CG had similar GL volumes in both sides (P = 0.11 and P = 0.19, for the dominant and contralateral GL, respectively). GL was asymmetrically hypertrophied in TP. The non-dominant GL volume was 20% greater in TP than in CG (Psoccer is associated to a symmetric hypertrophy of IL. Gluteal muscles are asymmetrically hypertrophied in TP, while SP display a similar size to that observed in controls. It remains to be determined whether the different patterns of IL and GL hypertrophy may influence the risk of injury. PMID:21829539

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

    GOH PIN SIANG

    2013-12-01

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

  14. Part 8. Deployment considerations

    Dance, K.D.; Chang, Y.I.; Daly, T.A.

    1980-01-01

    This report addresses considerations of fast breeder reactor development and deployment from a national perspective. Nations vary greatly in their expertise and interest relative to nuclear power, and hence a single set of steps to be taken by a nation in decision-making on breeder development and deployment cannot be presented. The approach taken in this report is to present discussions on key factors influencing the breeder development and deployment decisions, especially in non-breeder nations, by drawing upon historical perspectives of the Light Water Reactor for comparison

  15. Geophysical considerations of geothermics

    Hayakawa, M

    1967-01-01

    The development and utilization of geothermal energy is described from the standpoint of geophysics. The internal temperature of the Earth and the history and composition of magmas are described. Methods of exploration such as gravity, magnetic, thermal and electrical surveys are discussed, as are geochemical and infrared photogrammetric techniques. Examples are provided of how these techniques have been used in Italy and at the Matsukawa geothermal field in Japan. Drilling considerations such as muds, casings and cementing materials are discussed. Solutions are proposed for problems of environmental pollution and plant expansion.

  16. Storage array reflection considerations

    Haire, M.J.; Jordan, W.C.; Taylor, R.G.

    1997-01-01

    The assumptions used for reflection conditions of single containers are fairly well established and consistently applied throughout the industry in nuclear criticality safety evaluations. Containers are usually considered to be either fully water-reflected (i.e. surrounded by 6 to 12 in. of water) for safety calculations or reflected by 1 in. of water for nominal (structural material and air) conditions. Tables and figures are usually available for performing comparative evaluations of containers under various loading conditions. Reflection considerations used for evaluating the safety of storage arrays of fissile material are not as well established

  17. Tracking of ball and players in beach volleyball videos.

    Gabriel Gomez

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

  18. Tracking of Ball and Players in Beach Volleyball Videos

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

    2014-01-01

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

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

    Novak, Dario; Vucetić, Vlatko; Zugaj, Sanja

    2013-05-01

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

  20. Linking performance decline to choking: players' perceptions in basketball.

    Fryer, Ashley Marie; Tenenbaum, Gershon; Chow, Graig M

    2018-02-01

    This study was aimed at examining how basketball players view unexpected performance errors in basketball, and under what conditions they perceive them as choking. Fifty-three basketball players were randomly assigned into 2 groups (game half) to evaluate the linkage between performance decline and choking as a function of game-time, score gap and game half. Within each group, players viewed 8 scenario clips, which featured a different player conducting an error, and subsequently rated the extent of performance decline, the instance of choking and the salience of various performance attributions regarding the error. The analysis revealed that choking was most salient in the 2nd half of the game, but an error was perceived as choking more saliently in the beginning of the 2nd half. This trend was also shown for players' perception of performance decline. Players' ratings of the attributions assigned to errors, however, revealed that during the end of the 2nd half, time pressure and lack of concentration were the causes of errors. Overall, the results provide evidence towards a conceptual framework linking performance decline to the perception of choking, and that errors conducted by players are perceived as choking when there is not a salient reason to suggest its occurrence.

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

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

    2016-12-01

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

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

    Govind B. Taware

    2013-07-01

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

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

    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

  4. The players of the photovoltaic sector in France

    Houot, G.

    2012-01-01

    This document reviews 338 players in the French photovoltaic industry. Each player can be the owner of a photovoltaic power plant, or its operator, or the manufacturer of photovoltaic systems, or the manufacturer of components involved in photovoltaic systems, or the equipment wholesaler, or the designer of photovoltaic projects, or the photovoltaic system installer. For each player some pieces of information are gathered: a brief history of the enterprise, the enterprise activity, its staff, its turnover, its main achievements and its prospects. (A.C.)

  5. Vitamin D profile in National Football League players.

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

    2015-05-01

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

  6. Design of a WAV audio player based on K20

    Xu Yu

    2016-01-01

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

  7. CAREER TRANSITION FROM JUNIOR TO SENIOR IN BASKETBALL PLAYERS

    Alberto Lorenzo

    2009-01-01

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

  8. Personality traits and life satisfaction among online game players.

    Chen, Lily Shui-Lien; Tu, Hill Hung-Jen; Wang, Edward Shih-Tse

    2008-04-01

    The DFC Intelligence predicts worldwide online game revenues will reach $9.8 billion by 2009, making online gaming a mainstream recreational activity. Understanding online game player personality traits is therefore important. This study researches the relationship between personality traits and life satisfaction in online game players. Taipei, Taiwan, is the study location, with questionnaire surveys conducted in cyber cafe shops. Multiple regression analysis studies the causal relationship between personality traits and life satisfaction in online game players. The result shows that neuroticism has significant negative influence on life satisfaction. Both openness and conscientiousness have significant positive influence on life satisfaction. Finally, implications for leisure practice and further research are discussed.

  9. “La deportista moderna”: género, clase y consumo en el fútbol, running y hockey argentinos

    Gabriela Garton

    2018-04-01

    Full Text Available The advances achieved by the feminist movement since the 1970s have also been reflected in athletics, evidenced by the exponential growth in the participation of women. This change has produced new ideals of the female body –one that is strong, athletic, independent, and at the same time sexually attractive– which have been constructed by Western society and fostered by its mercantilist logic through advertising, social networks and certain messages about caring for your body and leading a “healthy lifestyle” chosen by brands which exploit these ideals. We analyze the image of women in three sports where women have reached unprecedented levels of participation and visibility: field hockey, soccer and running. Our study is based on ethnographic field work, along with the analysis of a series of advertisements, videos and pictures on social networks, where such women are portrayed, or self-represented, as models/examples of the new ideal of the female body. In this way, we hope to throw light on the ideals found in the sports women choose to practice and ask whether individual freedom and agency still exist in these activities. We also wonder if the hegemonic ideals of femininity continue to operate there or if the truth lies somewhere between the two alternatives.

  10. Physical Fitness Qualities of Professional Rugby League Football Players: Determination of Positional Differences.

    Meir, Rudi; Newton, Robert; Curtis, Edgar; Fardell, Matthew; Butler, Benjamin

    2001-01-01

    Australian and English professional rugby players completed various physical fitness performance tests to determine differences when grouping players into three different rugby positional categories. Results found minimal differences in test scores on the basis of players' specific positions on a team, however, when players were grouped according…

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

    Michalsik, L B; Aagaard, Per; Madsen, K

    2013-01-01

    The purpose of this study was to determine the physical demands and match-induced impairments in physical performance in male elite Team Handball (TH) players in relation to playing position. Male elite TH field players were closely observed during 6 competitive seasons. Each player (wing players...

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

    De Jaegher, K.J.M.

    2015-01-01

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

  13. Somatotype and performance in female futsal players

    Gleber Pereira

    2008-01-01

    Full Text Available The present study aimed to verify whether body somatotype was indicative of competitive success in female utsal (indoor soccer players. One hundred and twelve players (22.1 ± 5.4 years; 58.4 ± 6.9 kg; 161.8 ± 6.2 cm, from ten teams and seven different states, had participated in a national competition. The anthropometric date was analyzed using one-way ANOVA for repeated measures. The somatotype dispersion distance was applied to compare somatotypes between the champion team (reference and the other teams (from 2nd to 10th position. Anthropometric characteristics didnot differ signifi cantly among teams. The results showed that the endomorphic component was predominant in relation to the mesomorphic and ectomorphic component, irrespective of a team’s ranking at the end of the competition. Therefore, the body somatotypes of female futsal teams cannot be considered as indicative of their competitive success. Resumo O presente estudo teve como objetivo verificar se o somatotipo corporal pode ser considerado um indicador de desempenho em atletas de futsal feminino, levando em consideração a classifi cação das equipes em uma competição ofi cial. A população foi constituída de 112 jogadoras (22,1 ± 5,4 anos; 58,4 ± 6,9 kg; 161,8 ± 6,2 cm, pertencentes a dez equipes de sete estados que disputavam a competição. Os dados antropométricos foram analisados mediante ANOVA one-way para medidas repetidas. Para comparar o somatotipo da campeã (referência com o das demais classificadas (2ª a 10ª colocação na competição, recorreu-se ao cálculo da distância de dispersão do somatotipo. As características antropométricas das equipes não diferiram estatisticamente. Os resultados revelaram que a endomorfia foi predominante em relação à mesomorfia e ectomorfia, independente da classificação das equipes na competição. Neste caso, a classifi cação somatotipológico apresentada pela equipe vencedora, ou qualquer outra neste

  14. Physical activity profile of 2014 FIFA World Cup players, with regard to different ranges of air temperature and relative humidity

    Chmura, Paweł; Konefał, Marek; Andrzejewski, Marcin; Kosowski, Jakub; Rokita, Andrzej; Chmura, Jan

    2017-04-01

    The present study attempts to assess changes in soccer players' physical activity profiles under the simultaneous influence of the different combinations of ambient temperature and relative humidity characterising matches of the 2014 FIFA World Cup hosted by Brazil. The study material consisted of observations of 340 players representing 32 national teams taking part in the tournament. The measured indices included total distances covered; distances covered with low, moderate, or high intensity; numbers of sprints performed, and peak running speeds achieved. The analysis was carried out using FIFA official match data from the Castrol Performance Index system. Ultimately, consideration was given to a combination of three air temperature ranges, i.e. below 22 °C, 22-28 °C, and above 28 °C; and two relative humidity ranges below 60 % and above 60 %. The greatest average distance recorded (10.54 ± 0.91 km) covered by players at an air temperature below 22 °C and a relative humidity below 60 %, while the shortest (9.83 ± 1.08 km) characterised the same air temperature range, but conditions of relative humidity above 60 % ( p ≤ 0.001). Two-way ANOVA revealed significant differences ( p ≤ 0.001) in numbers of sprints performed by players, depending on whether the air temperature range was below 22 °C (40.48 ± 11.17) or above 28 °C (30.72 ± 9.40), but only where the relative humidity was at the same time below 60 %. Results presented indicate that the conditions most comfortable for physical activity on the part of players occur at 22 °C, and with relative humidity under 60 %.

  15. Effects of jaw clenching wearing customized mouthguards on agility, power and vertical jump in male high-standard basketball players

    Bernat Buscà

    2018-04-01

    Full Text Available Background/Objective: Basketball players commonly use mouthguards for protecting their mouths from collisions with other players. Besides, literature reports that specific types of mouthguards may become an ergogenic device that facilitates a powerful jaw clenching, and a subsequent concurrent activation potentiation through this remote voluntary contraction of the mandible muscles. Methods: A randomized within-subjects design was used to study the effects of this mechanism on muscular performance (vertical jump, agility, bench press power and leg press power into two different conditions (mouthguard and no mouthguard in high-standard basketball players (n = 13. A mean differences analysis and a responder analysis were conducted. Results: Significant improvements were found (p < 0.05 in all vertical jump protocols using the mouthguard when compared to the no mouthguard conditions. However, no significant differences were found between the two conditions in agility and power (except in one load of bench press. Nevertheless, p-values were closer to statistical significance when analyzing the total time for the agility T-Test than when the first split time was under consideration (p = 0.111 and p = 0.944, respectively. Conclusion: This study demonstrated that the use of custom-made, bite-aligning mouthguard had an ergogenic effect on jump outcomes and inconclusive results in agility T-Test in professional basketball players. From the results obtained in the present study, the use of this type of mouthguards seems to be more justified in power actions on the court than in the strength and conditioning sessions at the gym in well-trained players. Keywords: Agility, Ergogenic effects, Jump ability, Mouthpiece, Power

  16. [PREVALENCE OF DEHYDRATION BEFORE TRAINING IN PROFESIONAL CHILEAN SOCCER PLAYERS].

    Castro-Sepúlveda, Mauricio; Astudillo, Sebastian; Álvarez, Cristian; Zapata-Lamana, Rafael; Zbinden-Foncea, Hermann; Ramírez-Campillo, Rodrigo; Jorquera, Carlos

    2015-07-01

    there is a lack of studies concerning hydration status before training in professional soccer player. to describe hydration status before regular training practices in professional soccer players. a total of 156 male soccer players (age 25.4 ± 5.2 y) from six professional Chilean clubs were included. No hydration or food intake recommendations were made before experiment, with the aim to assess hydration status under athlete's regular "real" conditions. Body mass, height and urine specific gravity (USG) measurements were performed before training practices. 98% of athletes showed dehydration (between moderate and severe) before regular training practices. dehydration is the most prevalent hydration status in professional Chilean soccer players before training, which may negatively affect athlete's performance and may increase their risk of heat-related injuries. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  17. Hypoconnectivity and Hyperfrontality in Retired American Football Players

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

    2013-10-01

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

  18. Psychological skills of provincial netball players in different playing ...

    South African Journal for Research in Sport, Physical Education and ... rugby union and American football players in different playing positions have been reported. These differences are believed to be the result of the specific demands of ...

  19. Psycho-social attributes of elite African women volleyball players ...

    Psycho-social attributes of elite African women volleyball players. ... 78% of them were influenced by family members to play volleyball, 81% continued to play the game due to success, and 64% envisaged that ... AJOL African Journals Online.

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

    Holmgård, Christoffer

    2016-01-01

    ." These methods for constructing procedural personas are then integrated with existing procedural content generation systems, acting as critics that shape the output of these systems, optimizing generated content for different personas and by extension, different kinds of players and their decision making styles......How can player models and artificially intelligent (AI) agents be useful in early-stage iterative game and simulation design? One answer may be as ways of generating synthetic play-test data, before a game or level has ever seen a player, or when the sampled amount of play test data is very low....... This thesis explores methods for creating low-complexity, easily interpretable, generative AI agents for use in game and simulation design. Based on insights from decision theory and behavioral economics, the thesis investigates how player decision making styles may be defined, operationalised, and measured...

  1. Training strategy of explosive strength in young female volleyball players

    Ana Pereira

    2015-01-01

    Conclusions: The 8-week combined jump and ball throwing training can significantly improve muscular performance in young female volleyball players. These findings may be useful for all physical education teachers and volleyball coaches.

  2. Real-Time Game Adaptation for Optimizing Player Satisfaction

    Yannakakis, Georgios; Hallam, John

    2009-01-01

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

  3. Epidemiology of injuries in female high school soccer players.

    ... commonly injured. Keywords: Epidemiology, soccer injuries, youth ... fun and enjoyment while burning up calories especially when electronic devices ... ture on female soccer players has also grown significant- ly9,10. In the last decade, ...

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

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

    2013-01-01

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

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

    Ostrovsky M.V.

    2010-02-01

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

  6. Physical and physiological profiles of Boland netball players

    Netball, as a team sport, is an interval- ... intensity, short bursts of movement and less intense recovery periods. ... tiveness of a training programme can be evaluated. Feedback ..... the Boland players also had a higher body fat percentage than.

  7. Preferred Leadership Behaviours of Male and Female Badminton Players

    Rajkumar S HARMA

    2015-06-01

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

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

    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

  9. Mental Toughness Attributes of Junior Level Medalist Badminton Players

    Varghese C. Antony

    2016-10-01

    Full Text Available The study aims to compare the mental toughness attributes between medalist and non-medalist badminton players and between male and female players. Participants were 15 male and 15 female badminton players aged between 13-19 years (M= 15.71, SD=2.82. Mental toughness questionnaire of Tiwari and Sharma was administered and the data were analyzed by using descriptive statistics and t-test. Medalist players have exhibited higher mean values on self-confidence, attention control, motivation and goal setting attributes. Overall mental toughness of medalists was higher 180.80±17.15 than non-medalists 170.25±20.10. Comparison analysis showed significant difference between medalists and non-medalists on mental toughness attributes: Self-confidence (SCO: p=0.001<0.05, medalists scored (M±SD=31.33±2.10 higher than non-medalists; motivation (MOT: p=0.006<0.05, medalist scored higher (M±SD=33.50±4.07; goal setting (GSE: p=0.044<0.05, medalists scored significantly higher (M±SD=33.55±4.11 than non-medalists. Other attributes did not show any significant difference between medalist and non-medalist players. When compared with gender, no significant difference was observed on mental toughness attributes except attention control (ATNCON: p=0.044<0.05, female players scored (M±SD=38.97±3.08 higher than male players. The findings confirm that mental toughness is a desired attribute which differentiates a medalist and non-medalist player. Connaughton et al., (2007 stated that elite competitive athletes possess better mental toughness. Medalist players displayed better self-confidence than the non-medalists as supported by Kuan and Roy (2007, Loehr (1986. Motivation helps players to achieve their best and enhance mental toughness (Connaughton et al., 2008; Mohammad et al., 2009. Goal setting determines successful performance Weinberg and Weigand (1993, Weinberg (2003. It was concluded that medalist badminton players showed better mental toughness

  10. Vulnerability Analysis of the Player Command and Control Protocol

    2012-06-14

    client plug-ins currentl:v only exist for C++, . Java . and Python. Player is designed a.’:i a. client-server architecture in which robots running Player...I 0.. double -1.0272 angular velocity ;.... ~ va t- <ll ~ 38 2D 73 65 * :>, ""’::!’ ell I 0, +’ 00 00 00 01 uint8 t state 1 motor state v .S 2.5

  11. The Player, the Controller and the amazing Avatar

    Sandvik, Kjetil

    Playing computer games consists of an interplay between the player's body movements in the physical world and the agency of game characters in the game's virtual environment with the controller as a mediator remediating the movements of the player in physical space into the actions of the avatar ...... both the avatars bodily movements, it also represents the very tool which the avatar is using when performing its actions, e.g. a sword or a tennis catcher....

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

    Chang, Ju-Hui; Zhang, Hongxia

    2008-12-01

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

  13. The strategy of players on the European gas market

    Lecarpentier, A.

    2006-01-01

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

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

    Andrzejewski Marcin

    2016-12-01

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

  15. Different injury pattern in goalkeepers compared to field players

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

    2014-01-01

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

  16. Differences in Energy Capacities between Tennis Players and Runners

    Novak, Dario; Vučetić, Vlatko; Žugaj, Sanja

    2013-01-01

    The primary purpose of this study was to determine differences between elite athletes and tennis players in order to provide a clearer picture regarding the energy demands in modern tennis. Forty-eight (48) athletes and 24 tennis players from Croatian national leagues were compared in morphological and physiological parameters of an all-out incremental treadmill test with gas exchange measurements. Tennis players’ HRmax (192.96±7.75 bpm) shows values that are most different to 400-meters spri...

  17. Resbuffling of the electric power industries: internationalization new players, diversification

    Chevalier, J.M.; Salaun, D.

    1995-01-01

    The changes that are being brought in the forms of organization of the power industry lead to a global restructuring of the industry. Traditional players are forced to redefine their strategies concerning vertical and horizontal integration and also diversification. They tend to internationalize their business but they are facing aggressive new-comers. The future structure of the industry is not yet determined but there will be a great number of very different corporate players. (authors). 1 fig

  18. Player Modeling Using HOSVD towards Dynamic Difficulty Adjustment in Videogames

    Anagnostou , Kostas; Maragoudakis , Manolis

    2012-01-01

    Part 3: Second International Workshop on Computational Intelligence in Software Engineering (CISE 2012); International audience; In this work, we propose and evaluate a Higher Order Singular Value Decomposition (HOSVD) of a tensor as a means to classify player behavior and adjust game difficulty dynamically. Applying this method to player data collected during a plethora of game sessions resulted in a reduction of the dimensionality of the classification problem and a robust classification of...

  19. Upper extremity sensorimotor control among collegiate football players.

    Laudner, Kevin G

    2012-03-01

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

  20. Morphological and physiological profile of elite basketball players in Belgium

    Boone, Jan; Bourgois, Jan

    2013-01-01

    PURPOSE: The present study aimed to gain insight into the physiological profile of elite basketball players in Belgium in relation to their position on the field. METHODS: The group consisted of 144 players, divided into 5 groups according to position (point guards [PG], shooting guards [SG], small forwards [SF], power forwards [PF] and centers [C]). The anthropometrics were measured and the subjects underwent fitness tests (incremental running test, 10m-sprint,5x10m,Squat and Counter Move...