Hayward-Ellis, Julie; Alexander, Marion J L; Glazebrook, Cheryl M; Leiter, Jeff
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.
Mike R. Hellyer
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
Uzun, Ahmet; Metin KAYA; AYDOS, Latif; Kanatli, Ulunay; Esen, Erdinç
The aim of the present study was to compare the pedobarographic parameters of contact areas and maximal forces for 11 contact areas of foot-soles in professional male Ice hockey players and healthy people and to investigate the effect of Ice hockey on the foot-sole. The study consisted of 22 Ice hockey players without any foot-related complaints and as the control group, 25 male volunteers. EMED-SF plantar pressure analysis system was used in the study. Any statistically significant differen...
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.
Buckeridge, Erica; LeVangie, Marc C; Stetter, Bernd; Nigg, Sandro R; Nigg, Benno M
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 (pice mobile measurement approach offers potential for athlete monitoring, biofeedback and training advice.
Shell, Jaymee R; Robbins, Shawn M K; Dixon, Philippe C; Renaud, Philippe J; Turcotte, René A; Wu, Tom; Pearsall, David J
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.
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.
Allisse, Maxime; Sercia, Pierre; Comtois, Alain-Steve; Leone, Mario
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 hockey season, but not during the off-season where some degradation was observed. Finally, weak observed variances (generally 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.
Gilenstam, Kajsa M; Thorsen, Kim; Henriksson-Larsén, Karin B
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 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.
Chaze, Brian; McDonald, Patrick
Winter sports are often associated with high speed, which carries with it the potential for collision. As such, head injuries are among the more commonly encountered injuries in winter-related sporting activities. This article focuses on popular winter sports such as downhill skiing and snowboarding, sledding, snowmobiling, ice skating, and hockey. In virtually all of these activities, the incidence and severity of head injuries can be reduced by the use of appropriate protective headgear.
Stetter, Bernd J; Buckeridge, Erica; von Tscharner, Vinzenz; Nigg, Sandro R; Nigg, Benno M
This study presents a new approach for automated identification of ice hockey skating strides and a method to detect ice contact and swing phases of individual strides by quantifying vibrations in 3D acceleration data during the blade-ice interaction. The strides of a 30-m forward sprinting task, performed by 6 ice hockey players, were evaluated using a 3D accelerometer fixed to a hockey skate. Synchronized plantar pressure data were recorded as reference data. To determine the accuracy of the new method on a range of forward stride patterns for temporal skating events, estimated contact times and stride times for a sequence of 5 consecutive strides was validated. Bland-Altman limits of agreement (95%) between accelerometer and plantar pressure derived data were less than 0.019 s. Mean differences between the 2 capture methods were shown to be less than 1 ms for contact and stride time. These results demonstrate the validity of the novel approach to determine strides, ice contact, and swing phases during ice hockey skating. This technology is accurate, simple, effective, and allows for in-field ice hockey testing.
Henriksson, Tommy; Vescovi, Jason D; Fjellman-Wiklund, Anncristine; Gilenstam, Kajsa
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
Lignell, Erik; Fransson, Dan; Krustrup, Peter; Mohr, Magni
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 NHL 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-h 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 4606±219 m (2260-6749 m), of which high-intensity distance was 2042±97 m (757-3026 m). Sprint-skating speed was 5-8% higher (Pice 47% longer. However, F performed 54% more (Pice 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 to 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 specific physical match performance.
Boland, Michelle; Miele, Emily M; Delude, Katie
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.
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
effrey M. Janot, Nicholas M. Beltz, Lance D. Dalleck
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.
Lamoureux, Nicholas R; Tomkinson, Grant R; Peterson, Benjamin J; Fitzgerald, John S
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 eight 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% CI]: V[Combining Dot Above]O2, 0.46 [0.09, 0.72]; 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.
In this paper I use auto-ethnography to illuminate how the sporting space of hockey can construct understandings of race and masculinity. Through personal vignettes I carve out the ways I am read as a black male within the space of hockey, while at the same time re-constructing my own identity as a black male through the writing process. Thus this paper uses evocative forms of writing to engage the reader and open up a dialogue about the ways race and gender structure the space of sport.
Power, Allan; Faught, Brent E.; Przysucha, Eryk; McPherson, Moira; Montelpare, William
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…
Hache, A. [Moncton Univ., NB (Canada). Dept. of Physics and Astronomy
A new hockey skate using a heated blade, called the Therma Blade, cuts ice friction by half, thereby improving skating performance but has created questions about melting and damage of the ice surface. This paper discussed the effect of the heated skate blade on the ice surface. The paper discussed the thermal power produced by the Therma Blade skate, the ice melting capacity of the therma blade, and the ice temperature profile around the heated blade. It also examined the power dissipation by friction comparing the cold versus the heated blade. Units and definitions as well as conversion factors were also presented in appendix format. Constants and technical specifications were listed in an appendix. It was concluded that the maximum melting capacity of the therma blade is 0.7 grams of ice per skate per minute. This is the upper limit as set by the laws of physics, and this requires the skate to be completely static over ice at 0 degrees Celsius and all the power drawn by the battery to reach the ice friction force. 5 refs., 1 tab., 2 figs.
Jaime Segundo Cuesta Pérez
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 depor...
Jaime Segundo Cuesta Pérez
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.
Gagnon, Micheline; And Others
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)
Koga, Yuzo; Nishimura, Tetsu; Watanabe, Naoki; Okamoto, Kousuke; Wada, Yuhei
A motion on sports has been studied by many researchers from the view of the medical, psychological and mechanical fields. Here, we try to analyze a speed skating motion dynamically for an aim of performing the best record. As an official competition of speed skating is performed on the round rink, the skating motion must be studied on the three phases, that is, starting phase, straight and curved course skating phase. It is indispensable to have a visual data of a skating motion in order to analyze kinematically. So we took a several subject's skating motion by 8 mm video cameras in order to obtain three dimensional data. As the first step, the movement of the center of gravity of skater (abbreviate to C. G.) is discussed in this paper, because a skating motion is very complicated. The movement of C. G. will give an information of the reaction force to a skate blade from the surface of ice. We discuss the discrepancy of several skating motion by studied subjects. Our final goal is to suggest the best skating form for getting the finest record.
van der Kruk, E.
Speed skating is a rather special form of locomotion. While in most types of human locomotion, humans generate forces by pushing against the environment in the opposite direction of motion, in speed skating the skater pushes sideward to propel himself forward; Insight in the details of the technique
J. M. J. van Leeuwen
Full Text Available The friction of a stationary moving skate on smooth ice is investigated, in particular in relation to the formation of a thin layer of water between skate and ice. It is found that the combination of ploughing and sliding gives a friction force that is rather insensitive for parameters such as velocity and temperature. The weak dependence originates from the pressure adjustment inside the water layer. For instance, high velocities, which would give rise to high friction, also lead to large pressures, which, in turn, decrease the contact zone and so lower the friction. The theory is a combination and completion of two existing but conflicting theories on the formation of the water layer.
Runner, Aaron R; Lehnhard, Robert A; Butterfield, Stephen A; Tu, Shihfen; OʼNeill, Terrence
The purpose of this study was to examine the relationship between commonly employed dry-land performance tests and skating speed in male collegiate ice hockey players. Forty male National Collegiate Athletic Association Division I hockey players were tested on the following performance variables: vertical jump (VJ), standing broad jump, 40-yard dash, and maximal back squat (SQT). The subjects also performed 3 skating tests: the 90-ft forward acceleration test, the 90-ft backward acceleration test, and the 50-ft flying top speed test (F50). Pearson correlation coefficients were applied to compare the strength of association between each selected off-ice measure and each on-ice measure. Three multiple regression equations were then used to compare the weighted strengths of association between predictor and criterion variables. Only VJ showed significance in relation to skating speed (p = 0.011). These results suggest that meaningful performance testing in ice hockey players should occur mainly on the ice.
Peterson, Ben J; Fitzgerald, John S; Dietz, Calvin C; Ziegler, Kevin S; Ingraham, Stacy J; Baker, Sarah E; Snyder, Eric M
Current research has found anthropometric and physiological characteristics of hockey players that are correlated to performance. These characteristics, however, have never been examined to see whether significant differences exist between on- and off-ice performance markers at different levels of play; Division I, Elite Junior, and Division III. The purpose of this study was to examine the differences that may exist between these characteristics in Division I (24), Elite Junior (10), and Division III hockey (11) players. Forty-five (age: 18-24 years) hockey players completed anthropometric, on-ice, and off-ice tests to ascertain average measures for each division of play. On-ice testing was conducted in full hockey gear and consisted of acceleration, top-speed, and on-ice repeated shift test (RST). Off-ice tests included vertical jump, Wingate, grip strength, and a graded exercise test performed on a skating treadmill to ascertain their (Equation is included in full-text article.). Division I players had significantly lower body fat than their Division III peers (p = 0.004). Division I players also scored significantly better on measures of anaerobic power; vertical jump (p = 0.001), Wingate peak power (p = 0.05), grip strength (p = 0.008), top speed (p = 0.001), and fastest RST course time (p = 0.001) than their Division III counterparts. There was no significant difference between Division I and Elite Junior players for any on- or off-ice performance variable. The results of this study indicate that performance differences between Division I and Division III hockey players seem to be primarily because of the rate of force production.
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.
van der Eb, J.W.; Zandee, Willem; van der Bogaard, Timo; Veeger, H.E.J.; Beek, Peter
The force produced to propel a body forward in speed skating is directed almost perpendicular to the forward motion, because a skate moves nearly frictionless in the for-aft direction and more or less fixed (against the ice) in sideways lateral direction, resulting in a sliding point to push off
van der Eb, J.W.; Zandee, Willem; van der Bogaard, Timo; Veeger, H.E.J.; Beek, P.J.
The force produced to propel a body forward in speed skating is directed almost perpendicular to the forward motion, because a skate moves nearly frictionless in the for-aft direction and more or less fixed (against the ice) in sideways lateral direction, resulting in a sliding point to push off
Nathan J Washington
Full Text Available Background: Australia’s interest and participation in ice hockey is increasing, however a lack of access to facilities means familiarity with this sport is limited, and so too is the facilitation of skill development within an ecologically valid context. Objective: While numerous methods may be employed to address this, one resource which remains relatively unexplored is the StrideDeck Treadmill, therefore the purpose of this study was to investigate the effectiveness of this equipment with specific reference to the biomechanical changes for skating ability. Methods: N = 16 male athletes (Mage = 15.0 ± 0.76 yrs from a junior league competition participated in this intervention based study. n = 9 were assigned to the training intervention (StrideDeck once a week, while the control group (n = 7 continued their normal training routines. Further, monthly sprint tests both on the StrideDeck and an on-ice protocol were conducted to track progress via kinematic analysis. Results: Data analysis revealed no significant overall effects for on-ice sprint skating performance after StrideDeck training; however there were significant kinematic differences between StrideDeck and ice conditions. Conclusions: Therefore while the StrideDeck may have merit in regard to physiological paramters, the results of this study do not support its use as a skill acquisition tool in regard to increasing skating ability. Keywords: Simulation training, skill acquisition, treadmill, ice skating, ice hockey skating, ice skating stride
van Hilst, Jony; Hilgersom, Nick F J; Kuilman, Miriam C; Kuijer, P Paul F M; Frings-Dresen, Monique H W
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 performed among 236 young elite athletes aged between 14–25 years in field hockey, football and speed skating. One hundred and eighty one (n = 181) athletes responded (response rate 77%). The overall, 12-month prevalence of LBP for the three sports was 60%: field hockey 56%, football 64% and speed skating 60%. Satisfaction with their own performance (OR = 0.5 95%CI:0.3–0.9) and with the coaching staff (OR = 0.5, 95%CI:0.4–0.8) were associated with a lower occurrence of LBP in field hockey. No sport-related risk factors were found in football. In speed skating more training hours (OR = 1.1, 95%CI:1.0–1.2), performance of Pilates (OR = 4.1, 95%CI:1.1–15.7) and more time spent on warming up (OR = 1.1, 95%CI:1.0–1.1) were associated with the occurrence of LBP. Prevalence of LBP among young elite athletes compared to the general age-related population was 3–5 times higher. Sport-related risk factors of LBP were found in field hockey and in speed skating.
Simard, Clermont; And Others
Study of the effect of a supplemental carbohydrate intake for seven elite ice hockey players before and during a game demonstrated that the supplement could result in less glycogen usage per distance skated, which had important implications for athletes who may participate in more than one game a day. (Author/CB)
Sim, Franklin H.; Simonet, William T.
The article describes the mechanisms, management, and prevention of each type of injury to which hockey players are prone. It surveys the injuries sustained by ice hockey players and discusses treatment of specific injuries, including those injuries to the head, eye, shoulder, hand, thigh, scalp, and face. (JL)
Abbott, Kristin; Hecht, Suzanne
Synchronized skating is a unique sport of team skating and currently represents the largest competitive discipline in U.S. Figure Skating. Synchronized skating allows skaters to compete as part of a team with opportunities to represent their country in international competitions. As the popularity of the sport continues to grow, more of these athletes will present to sports medicine clinics with injuries and illnesses related to participation in synchronized skating. The purpose of this article is to review the common injuries and medical conditions affecting synchronized skaters.
Van Der Kruk, E.; Schwab, A. L.; Van Der Helm, F. C.T.; Veeger, H. E.J.
To assist speed skaters in improving their skating performance, we would like to provide them with real time feedback on the orientation of the skate within a single stroke. While of course the forces generated by the skater on the ice determine the acceleration of the skater, the orientation of the
van der Kruk, E.; Schwab, A.L.; van der Helm, F.C.T.; Veeger, H.E.J.; van der Helm, FCT; Jansen, AJ
To assist speed skaters in improving their skating performance, we would like to provide them with real time feedback on the orientation of the skate within a single stroke. While of course the forces generated by the skater on the ice determine the acceleration of the skater, the orientation of
Kim, Hyeyoung; Hwang, Sujin; Lee, Byoung-Hee
[Purpose] To investigate sports injuries in Korean national ice hockey players by surveying parts, times, types, frequency, cure, and prevention types of sports injuries and provide basic data for injury prevention and performance improvement of ice hockey players. Another purpose of this study was to evaluate the incidence of ice hockey injuries according to age and the relationship between etiological factors and injuries in high school students. [Subjects and Methods] This was a cross-sectional study. Eighteen female ice hockey players in Korean elite athletes were recruited for this study. This study was conducted by a self-administered questionnaire survey using Knee Injury and Osteoarthritis Outcome Score (KOOS) of national ice hockey players. [Results] Participants were injured mainly during training. Injuries were caused by skate, puck-contact, and body check. Five subscales of KOOS were significantly correlated with each other except that the correlation between activities of daily living and quality of life was insignificant. [Conclusion] For injury prevention in national team ice hockey players, full gear is recommended. In addition, therapist in the field needs to conduct injury prevention through consistent observations and counseling in order to prevent injury and improve performance. Ice hockey players also need sufficient rest with systematic and scientific training for injury prevention and performance improvement.
Hegge, Ann Magdalen; Ettema, Gertjan; de Koning, Jos J; Rognstad, Asgeir Bakken; Hoset, Martin; Sandbakk, Øyvind
This study analyzed the biomechanical and physiological effects of the arm swing in roller ski skating, and compared leg-skating (i.e. ski skating without poles) using a pronounced arm swing (SWING) with leg-skating using locked arms (LOCKED). Sixteen elite male cross-country skiers performed submaximal stages at 10, 15 and 20kmh(-1) on a 2% inclined treadmill in the two techniques. SWING demonstrated higher peak push-off forces and a higher force impulse at all speeds, but a longer cycle length only at the highest speed (all Pski skating increases the ski forces and aerobic energy cost at low and moderate speeds, whereas the greater forces at high speed lead to a longer cycle length and smaller anaerobic contribution. Copyright © 2014 Elsevier B.V. All rights reserved.
Bonfield, Christopher M; Wecht, Daniel A; Lunsford, L Dade
Ice hockey is an aggressive and fast-paced sport which has a high risk of injury, concussions in particular. Although serious head injury has been recognized for nearly 50 years, an increase in mainstream media attention in recent years has led to unprecedented public awareness. As a result, the National Hockey League (NHL) and other professional leagues around the world have initiated concussion protocols in order to better prevent, recognize, and treat concussions. With over 1,000,000 youth hockey participants in Canada and the USA combined, concussion is an issue that reaches beyond the professional level. In this report we review the incidence, evaluation, treatment, return-to-play protocol, and prevention efforts related to concussion in ice hockey. © 2014 S. Karger AG, Basel.
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.
Benson, Brian W; Meeuwisse, Willem H
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.
Capin, Jacob J; Behrns, William; Thatcher, Karen; Arundale, Amelia; Smith, Angela Hutchinson; Snyder-Mackler, Lynn
Synopsis The literature pertaining to the rehabilitation of ice hockey players seeking to return to sport after anterior cruciate ligament reconstruction (ACLR) is currently limited. The purpose of this clinical commentary was to present a criterion-based progression for return to ice hockey for athletes after ACLR. First, we review pertinent literature and provide previously published guidelines on general rehabilitation after ACLR. Then, we present a 4-phase, on-ice skating progression with objective criteria to initiate each phase. During the early on-ice phase, the athlete is reintroduced to specific demands, including graded exposure to forward, backward, and crossover skating. In the intermediate on-ice phase, the emphasis shifts to developing power and introducing anticipated changes of direction within a controlled environment. During the late on-ice phase, the focus progresses to developing anaerobic endurance and introducing unanticipated changes of direction, but still without other players or contact. Finally, once objective return-to-sport criteria are met, noncontact team drills, outnumbered and even-numbered drills, practices, scrimmages, and games are progressively reintroduced during the return-to-sport phase. Recommendations for off-ice strength and conditioning exercises complement the on-ice progression. Additionally, we apply the return-to-hockey progression framework to a case report of a female collegiate defensive ice hockey player who returned to sport successfully after ACLR. This criterion-based return-to-hockey progression may guide rehabilitation specialists managing athletes returning to ice hockey after ACLR. J Orthop Sports Phys Ther 2017;47(5):324-333. Epub 29 Mar 2017. doi:10.2519/jospt.2017.7245.
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.
van der Kruk, E.; den Braver, O.; Schwab, A.L.; van der Helm, F.C.T.; Veeger, H.E.J.
In the current project, we aim to provide speed skaters with real-time feedback on how to improve their skating performance within an individual stroke. The elite skaters and their coaches wish for a system that determines the mechanical power per stroke. The push-off force of the skater is a
van der Kruk, E.; den Braver, O.; Schwab, Arend L.; van der Helm, Frans C T; Veeger, H. E J
In the current project, we aim to provide speed skaters with real-time feedback on how to improve their skating performance within an individual stroke. The elite skaters and their coaches wish for a system that determines the mechanical power per stroke. The push-off force of the skater is a
Wall, W. A., Jr.
New welding skate concept for automatic TIG welding of contoured or double-contoured parts combines lightweight welding apparatus with electrical circuitry which computes the desired torch angle and positions a torch and cold-wire guide angle manipulator.
MacIntyre, Kyle; Gomes, Brendan; MacKenzie, Steven; D'Angelo, Kevin
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. 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. 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.
... United States; Northeast Skate Complex Fishery; Reduction of Skate Wing Fishery Possession Limit AGENCY.... ACTION: Temporary rule; inseason adjustment. SUMMARY: NMFS announces the reduction of the skate wing fishery possession limit for the Skate Management Unit for the remainder of the 2010 fishing year...
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
P. L. Diachek
Full Text Available The paper considers design variants and requirements to temperature regime of an ice field which is used for organization of ice-hockey, figure skating and skating competitions. The purpose of the presented paper is to ensure the conditions which make it possible to obtain high sports results owing to preparation of an ice-field with the required characteristics. A heat-conductivity differential equation with due account of heat-exchange convective processes on the surface of an ice-field and radiation heat-exchange with surrounding structures has been solved with the help of numerical methods as applied to conditions of the problem.
Noordhof, Dionne A; Tok, Elmy van; Joosten, Florentine S J G M; Hettinga, Florentina J; Hoozemans, Marco J M; Foster Jr., Carl; Koning, Jos J de
Half the improvement in 1500-m speed-skating world records can be explained by technological innovations and the other half by athletic improvement. It is hypothesized that improved skating economy is accountable for much of the athletic improvement. PURPOSE: To determine skating economy in
Inkelis, S H; Stroberg, A J; Keller, E L; Christenson, P D
Many children who roller skate sustain injuries. To determine the type and severity of these mishaps, the medical records of 76 children less than 16 years of age with roller skating injuries presenting to two pediatric emergency departments were reviewed. Seventy-five percent were girls, and 25% were boys. The upper extremity was the most common body part injured (74%) (P less than 0.0001). Lower extremity injuries occurred in 12%, head and face injuries in 10%, and chest injuries in 4%. The most common type of injury was a fracture (69%), with the wrist and forearm being most frequently fractured (53%). Hospitalization and long-term sequelae were infrequent. Younger children (less than or equal to 9) had an increased frequency of fracture injury (P less than 0.02). This is most likely because maturation of lower and upper extremity speed, strength, agility, coordination, balance, and reaction time and morphologically stronger bones combine to afford relative protection to the older child. Physicians and parents need to be aware of a child's skill level before the child is encouraged to roller skate. Measures which may decrease the likelihood of injury include protective gear, instruction in roller skating technique, learning to skate in an uncongested area on level, familiar terrain, and learning to fall properly.
Stull, Justin D; Philippon, Marc J; LaPrade, Robert F
Femoroacetabular impingement (FAI) is becoming a prevalent overuse injury diagnosis among hockey players. In the adult ice hockey stride, the "at-risk" hip position, defined by internal rotation during flexion and external rotation during abduction, reportedly increases hip vulnerability to labral injury as a result of FAI. Peewee youth ice hockey players display the kinematics for both described at-risk hip positions (internal rotation during flexion and external rotation during abduction) in the ice hockey sprint start. Descriptive laboratory study. Twelve healthy male Peewee ice hockey players (mean age, 10.8 ± 0.6 years) participated in this study. Thirty-five anatomic landmarks were used to analyze the 3-dimensional kinematic and kinetic variables of the hip associated with the ice hockey sprint start. Ten high-speed (120-Hz) infrared cameras recorded the trials, which were subsequently analyzed with Motion Monitor software. The sprint start was recorded over 4 defined periods of motion: start, push, swing, and even. In the "push" period, 11.5° of external rotation was observed concurrently with 13.2° of abduction in the push leg, and 6.8° of internal rotation occurred with 33.8° of flexion in the lead leg. During the recovery phase of the "swing" period, maximum internal rotation was 5.6° with concurrent hip flexion of 44.2° in the push leg, while lead leg internal rotation reached a maximum of 10.8° with hip flexion of 35.1° during the "even" period. During the sprint start, youth ice hockey players externally rotate in abduction during the push-off phase and internally rotate through increasing hip flexion during the recovery phase, displaying the at-risk hip positions of the ice hockey skating stride. During the sprint start, youth ice hockey players position their hips in a manner that can cause impingement of the femoral neck against the acetabulum and potentially lead to labral tears and/or articular cartilage damage. This knowledge could be
van der Kruk, E.; van der Helm, F.C.T.; Schwab, A.L.; Veeger, H.E.J.
Pushoff in speed skating requires an extensive motion strategy. During speed skating the skater continuously changes the lean and steering angle of the skate and therewith the direction of push-off, The forces in an inertial coordinate system can give insight into what amount of the push-off force
... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Skate FMP review and monitoring. 648.320... Measures for the NE Skate Complex Fisheries § 648.320 Skate FMP review and monitoring. (a) Annual review and specifications process. The Council, its Skate Plan Development Team (PDT), and its Skate Advisory...
Full Text Available Background: Biological motion affords the observer a significant amount of relative information that allows the recognition of various features specific to an individual. These include; movement signatures based on locomotion, and gender, in addition to deception and intention. Recent research has also demonstrated it is possible to discriminate teammates from non-teammates when viewing brief (<500msec video footage of locomotion specific movement signatures. Further, correlations between recognition, familiarity, liking, reaction time, and movement time were present when observing familiar gait types (swimming and running. However it is not known whether these trends are also present for less common forms of gait such as ice-skating. Objective: The purpose of the present study was to investigate if; 1 ice hockey players could recognize teammates vs non-teammates from brief visual displays within sport relevant time and, 2 ice hockey players were influenced by factors such as familiarity and liking when making decisions associated with accuracy and latencies (RT, MT. Methodology: Participants (N=13 were required to determine the affiliation of skaters in a randomised video sequence of 23 skaters by indicating teammate or not using a latency device. The device captured choice accuracy, reaction time (RT and movement time (MT. They were then asked to complete two ranking tasks based on level of liking for each skater (social liking and pass choice liking. Results: Data analysis demonstrated that MT was significantly (p<0.05 longer when players perceived the skater as a non-teammate, regardless of decision accuracy, however no other analyses were significant. Conclusion: The results suggest that the perception of a less familiar (non-teammate individual presents a level of hesitation that affects MT. While this is less problematic within existing teams, newly formed representative teams may be more vulnerable to factors of familiarity or liking
Kuhn, Andrew W; Noonan, Benjamin C; Kelly, Bryan T; Larson, Christopher M; Bedi, Asheesh
Ice hockey is a fast, physical sport with unique associated biomechanical demands often placing the hip in forced and repetitive supraphysiological ranges of motion. Ice hockey players commonly endure and are sidelined by nebulous groin injury or hip pain. Underlying causes can be chronic or acute and extra-articular, intra-articular, or "hip-mimicking." This article serves to review common hip-related injuries in ice hockey. For each, we define the particular condition; comment on risk factors and preventive strategies; discuss key historical, physical examination, and imaging findings; and finally, suggest nonoperative and/or operative treatment plans. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.
Meyer, Ernst; Gnecco, Enrico
Simulations of nanoscale sharp tips sliding on a salt surface predict vanishing friction at temperatures close to the melting temperature, as the tip skates on a layer of liquefied salt. This insight opens the way to applications in MEMS, NEMS and auto/aerospace engines.
Noordhof, Dionne A; van Tok, Elmy; Joosten, Florentine S J G M; Hettinga, Florentina J; Hoozemans, Marco J M; Foster, Carl; de Koning, Jos J
Half the improvement in 1500-m speed-skating world records can be explained by technological innovations and the other half by athletic improvement. It is hypothesized that improved skating economy is accountable for much of the athletic improvement. To determine skating economy in contemporary athletes and to evaluate the change in economy over the years. Contemporary skaters of the Dutch national junior team (n = 8) skated 3 bouts of 6 laps at submaximal velocity, from which skating economy was calculated (in mL O 2 ・ kg -1 ・ km -1 ). A literature search provided historic data on skating velocity and submaximal V̇O 2 (in mL ・ kg -1 ・ min -1 ), from which skating economy was determined. The association between year and skating economy was determined using linear-regression analysis. Correcting the change in economy for technological innovations resulted in an estimate of the association between year and economy due to athletic improvement. A mean (± SD) skating economy of 73.4 ± 6.4 mL O 2 ・ kg -1 ・ km -1 was found in contemporary athletes. Skating economy improved significantly over the historical time frame (-0.57 mL O 2 ・ kg -1 ・ km -1 ・ y -1 , 95% confidence interval [-0.84, -0.31]). In the final regression model for the klapskate era, with altitude as confounder, skating economy improved with a nonsignificant -0.58 mL O 2 ・ kg -1 ・ km -1 ・ y -1 ([-1.19, 0.035]). Skating economy was 73.4 ± 6.4 mL O 2 ・ kg -1 ・ km -1 in contemporary athletes and improved over the past ~50 y. The association between year and skating economy due to athletic improvement, for the klapskate era, approached significance, suggesting a possible improvement in economy over these years.
Machado, Giancarlo Marques Carraro
Apesar da existência de dezenas de pistas de skate na cidade de São Paulo – espaços considerados “próprios” para o skate -, a maioria dos skatistas da modalidade street skate confere maior importância à prática feita nas ruas, onde, para muitos, se “anda de skate de verdade”. A atração que elas exercem é a possibilidade de encontrar diferentes tipos de picos, ou seja, equipamentos urbanos (bancos, corrimãos, escadas, canteiros) obstáculos onde se realizam as manobras. Este artigo busca analis...
Leuppi, J D; Kuhn, M; Comminot, C; Reinhart, W H
The prevalence of asthma was studied in a ice hockey team compared with both a floor ball team and the Swiss population. Lung function, bronchial hyperresponsiveness to methacholine, asthma symptoms and exercise-induced asthma were measured in a cross-sectional prospective study. A positive response to the methacholine bronchial provocation test was found in 34.6% of the ice hockey players and 20.8% of the floor ball players (Swiss population 16.4%). The provocative dose causing a 20% fall in the forced expiratory volume in one second (PD20) was significantly lower in ice hockey players than in floor ball players, but there was no significant difference in the dose-response slopes between the two groups. Asthma was diagnosed in 19.2% of the ice hockey players and in 4.2% of the floor ball players (Swiss population 6.8%), whereas exercise-induced asthma was found in 11.5% of the ice hockey players and in 4.2% of the floor ball players. In conclusion, asthma and bronchial hyperresponsiveness seemed to be more common in ice hockey players than in floor ball players and in the Swiss population. Strenuous exercise at lower temperatures may be a risk factor for the higher prevalence of asthma and bronchial hyperresponsiveness, as well as the increased severity of bronchial hyperresponsiveness, particularly in ice hockey players.
Geithner, Christina A; Lee, Amanda M; Bracko, Michael R
Positional differences have been examined in women's basketball, field hockey, netball, and volleyball, but not in elite women's ice hockey. Our purpose was to describe and compare physical, fitness, and skating performance characteristics of forwards (F), defensemen (D), and goalies (G). Subjects were 112 University of Alberta women players (21.4 +/- 2.9 years of age). A full anthropometric battery was conducted on each player. Heath-Carter anthropometric somatotypes were calculated. Percent body fat (%fat) was estimated from both general and population-specific equations. Subjects performed off-ice fitness tests (vertical jump, 40-yd dash, Leger test for predicting .V(O2)max) and on-ice fitness (Modified 3-Repeat Sprint Skate Test-MRSS, blood lactate after sprint test) and skating performance tests (6.10-m acceleration test, Cornering S-Turn Agility Test). Descriptive statistics and multivariate analyses of variance were run using SPSS (Version 10.0) for the MacIntosh, with a significance level set a priori at p G, F > G); relaxed arm circumference (D > F, G > F); supraspinale and biceps skinfolds (G > D, G > F); and endomorphy (G > F). Significant differences among positions were also found for the MRSS (G > D > F) and agility tests (G > D, G > F). D tended to have the most robust build overall. F were leaner than D and G, and their smaller relaxed arm circumference measurements most likely reflect less subcutaneous fat on the upper arm. F had greater anaerobic power than D, followed by G, and they tended to have greater aerobic capacity. F and D were more agile than G. Performance demands appear to be position specific. F need to be the most versatile and fit because of a greater amount and variety of work performed both during practices and games; their required degrees of versatility and fitness are followed by those required of D and G.
Whiteside, David; Deneweth, Jessica M; Bedi, Asheesh; Zernicke, Ronald F; Goulet, Grant C
Femoroacetabular impingement (FAI) is particularly prevalent in ice hockey. The butterfly goalie technique is thought to involve extreme ranges of hip motion that may predispose goaltenders to FAI. To quantify hip mechanics during 3 common goaltender movements and interpret their relevance to the development of FAI. Descriptive laboratory study. Fourteen collegiate and professional goaltenders performed skating, butterfly save, and recovery movements on the ice. Hip mechanics were compared across the 3 movements. The butterfly did not exhibit the greatest range of hip motion in any of the 3 planes. Internal rotation was the only hip motion that appeared close to terminal in this study. When subjects decelerated during skating—shaving the blade of their skate across the surface of the ice—the magnitude of peak hip internal rotation was 54% greater than in the butterfly and 265% greater than in the recovery. No movement involved levels of concomitant flexion, adduction, and internal rotation that resembled the traditional impingement (FADIR) test. The magnitude of internal rotation was the most extreme planar hip motion (relative to end-range) recorded in this study (namely during decelerating) and appeared to differentiate this cohort from other athletic populations. Consequently, repetitive end-range hip internal rotation may be the primary precursor to symptomatic FAI in hockey goaltenders and provides the most plausible account for the high incidence of FAI in these athletes. Resection techniques should, therefore, focus on enhancing internal rotation in goaltenders, compared with flexion and adduction. While the butterfly posture can require significant levels of hip motion, recovering from a save and, in particular, decelerating during skating are also demanding on goaltenders' hip joints. Therefore, it appears critical to consider and accommodate a variety of sport-specific hip postures to comprehensively diagnose, treat, and rehabilitate FAI. © 2015 The
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.
Poly Hockey is featured in this manual of instructions for coaches and teachers to use with mentally retarded boys and girls of all ages and ability levels. It is noted that the sport has been supported by the Board of Directors of the Special Olympics and has been used in Massachusetts for over 7 years. Explained is use of the game indoors, and…
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.
Coulson, M W; Denti, D; Van Guelpen, L; Miri, C; Kenchington, E; Bentzen, P
DNA-based identifications have been employed across broad taxonomic ranges and provide an especially useful tool in cases where external identification may be problematic. This study explored the utility of DNA barcoding in resolving skate species found in Atlantic Canadian waters. Most species were clearly resolved, expanding the utility for such identification on a taxonomically problematic group. Notably, one genus (Amblyraja) contained three of four species whose distributions do not overlap that could not be readily identified with this method. On the other hand, two common and partially sympatric species (Little and Winter skates) were readily identifiable. There were several instances of inconsistency between the voucher identification and the DNA sequence data. In some cases, these were at the intrageneric level among species acknowledged to be prone to misidentification. However, several instances of intergeneric discrepancies were also identified, suggesting either evidence of past introgressive hybridization or misidentification of vouchered specimens across broader taxonomic ranges. Such occurrences highlight the importance of retaining vouchered specimens for subsequent re-examination in the light of conflicting DNA evidence. © 2011 Blackwell Publishing Ltd.
Aalto, Akseli; Räihä, Tuukka
The main objective was to create an effective scouting tool to evaluate technical skills of an ice hockey player. The purpose was to provide an useful product for the Northern Hockey Experience Ltd. to be utilized in their services. A major factor with this project was to clarify the technical skills of ice hockey. In addition, other matters were to determine a skill, scouting in ice hoskey and feedback, without forgetting the evaluation of human performance. The product includes ...
Gachnang, F. [Eta Energietechnik GmbH, Winterthur (Switzerland); Mayer, H. [Gabathuler AG, Diessenhofen (Switzerland); Schweizer, A. [Baumgartner und Partner AG, Duebendorf (Switzerland); Krieg, J. [Zuercher Hochschule Winterthur, Winterthur (Switzerland)
This report for the Swiss Federal Office of Energy (SFOE) presents the results of three measurement projects that examined the effect of low-emission materials mounted under the roofing in three different ice rinks on the energy consumption for the refrigeration and air-conditioning installations. In the first object, an indoor ice-hockey rink in Duebendorf, Switzerland, the effect of an aluminium cladding installed and the measurements made concerning the reduction of energy consumption are discussed. Their relevance to further covered ice rinks is examined. The second part takes a look at the effect of soiling and oxidation examined at a further skating rink in Kreuzlingen, Switzerland. The third part of the report examines three different roofing constructions newly installed over an outdoor rink. The findings of the three projects are discussed and recommendations are made.
Larsen, Carsten H.
This article describes my experiences of working in Danish national junior ice hockey. I will describe the professional philosophy underpinning my services in ice hockey and I will outline the psychological services provided for the Danish junior national team that are derived from the context....... 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...
Dasiewicz, Patricia J; Conlon, J Michael; Anderson, W Gary
The vasoconstrictive and cardiovascular actions of a recently identified bradykinin (BK)-related peptide (Gly-Ile-Thr-Ser-Trp-Leu-Pro-Phe) from the little skate, Leucoraja erinacea were examined in the unanesthetised little skate. Intra-arterial administration of a skate BK (0.1-1 nmolkg(-1)) produced a hypertensive response with a rise in blood pressure reaching a maximum elevation of 28.7±4.8% over baseline (Pskate BK. Further, in vivo administration of 1 nmolkg(-1) skate BK induced a significant delayed increase in stroke volume (reaching a maximum of 54.4±14.7% above baseline) without significant effect on either cardiac output or heart rate. In vitro, skate BK constricted the 1st branchial, mesenteric (EC(50) 2.7×10(-9)M) and coeliac (EC(50) 3.1×10(-9)M) arterial preparations of the skate. In contrast, skate [Arg(9)]BK, the mammalian B(1) receptor agonist des-[Arg(9)]BK, and the mammalian B(2) receptor antagonist HOE-140 failed to induce vasoconstriction in these isolated arterial preparations. The vasoconstrictor actions of skate BK in the isolated mesenteric, coeliac and branchial arterial preparations were significantly inhibited when co-administrated with esculetin and phentolamine. Indomethacin also inhibited the vasoconstrictor actions of skate BK in the isolated branchial artery. We conclude that, as in mammals and teleost fish, multiple pathways involving at least the alpha adrenergic and leukotriene synthesis pathway are involved in mediating the vasoconstrictive actions of BK in vascular smooth muscle of the little skate. Copyright © 2011 Elsevier Inc. All rights reserved.
Natalia L Ruocco
Full Text Available Competition for food could be a major force driving changes in the community structure of skates (Rajidae subjected to fishing exploitation. Under this hypothesis, small skates are released from competition with larger skates after fishing has depleted the larger species. Here, we compare the abundance patterns of two sympatric skates with similar niches but different life histories, Bathyraja albomaculata (larger and slow-reproducing and Bathyraja macloviana (smaller and faster-reproducing, before (1971, 1978 and after (1998-2004 a 108% increase in industrial bottom trawling on the southeastern South American shelf in order to test the prediction that B. macloviana should competitively exclude B. albomaculata after the increase in fishing mortality. In 1971 and 1978, there was no relationship between the abundance of both species, indicating that they coexisted over large scales. In 1998-2004, the relationship between the abundances of these skates was bell-shaped, indicating that both species increased in abundance at low densities until peaking, after which B. albomaculata decreased when B. macloviana became more abundant, consistent with resource competition. We tested whether food may be a potential limiting resource by comparing the diet of both species. The two species consumed mostly polychaetes, differing only in the consumption of polychaetes from the family Nephthyidae, which was much higher for B. macloviana. Bathyraja macloviana could replace B. albomaculata at high densities when food resources may become scarce. These results support the hypothesis that competition release is an important factor explaining the changes in skate communities in overexploited areas.
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.
... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Use of roller skates, skateboards, roller skis, in-line skates, and similar devices. 13.916 Section 13.916 Parks, Forests, and... Special Regulations-Denali National Park and Preserve General Provisions § 13.916 Use of roller skates...
Wall, W. A.
This report summarizes progress of the automatic computerized weld skate development portion of the Computerized Weld Skate with Closed Circuit Television (CCTV) Arc Guidance Project. The main goal of the project is to develop an automatic welding skate demonstration model equipped with CCTV weld guidance. The three main goals of the overall project are to: (1) develop a demonstration model computerized weld skate system, (2) develop a demonstration model automatic CCTV guidance system, and (3) integrate the two systems into a demonstration model of computerized weld skate with CCTV weld guidance for welding contoured parts.
Castaldi, C R
Prior to 1975, craniofacial injuries were the most frequent of all ice hockey injuries. Through the cooperative efforts of hockey administrators, health professionals, sports standards organizations, and the introduction of mandatory protective equipment playing rules craniofacial injuries in youth, high school, and college hockey players in the United States have been almost eliminated. Blind eye injuries, once a major problem, no longer occur in players wearing certified full face protectors. The saving in health care costs for treating eye injuries alone is estimated to be upwards of $10 million annually. Despite the phenomenal success of amateur hockey organizations in eliminating most craniofacial injuries, such injuries continue to occur in recreational, "Old Timers," major junior, and professional hockey players because of failure to use the most effective types of protective equipment. The system established in the United States for preventing craniofacial injuries in the sports of ice hockey that involves youth, high school, and college hockey associations along with standards setting and certification procedures can serve as a model for all amateur sports throughout the world.
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
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
Nur, Sarah; Kendall, Marshall; Clark, J Michio; Hoshizaki, T Blaine
Goaltenders in ice hockey are the only players that are on the ice for the entire game. Their position exposes them to impacts from collisions with other players, falls to the ice, and puck impacts. In competitive ice hockey leagues, head injuries resulting from puck impacts have been reported with some cases resulting in ending the player's career. Considerable research has been conducted to assess the performance of hockey helmets; however, few have assessed the performance of goaltenders' masks. The purpose of this study was to compare the capacity of four goaltenders' masks for the protection from puck impact as measured by head acceleration and peak force. A Hybrid III headform was fitted with four different goaltender masks and impacted with a hockey puck in three locations at 25 m/s. The masks were found to vary in the level of protection they offered as the mask with the thickest liner resulted in lower forces than the thinnest mask for side impacts; however, the thinnest mask resulted in the lowest force for front impacts. Despite performance differences at specific locations, no one mask proved to be superior as peak acceleration and peak force values did not exceed the thresholds necessary for concussion.
Part of a series exploring how mathematics is used in the workplace. Software developers and statisticians record data of hockey games and players using statistics accessible to middle school students. (MM)
Grasaas, Erik; Hegge, Ann Magdalen; Ettema, Gertjan; Sandbakk, Øyvind
We investigated the effects of poling on physiological, kinematic and kinetic responses in the G4 skating technique where the poling movement is synchronized with the leg push-off on one side (strong side) followed by a forward arm swing during the leg push-off on the other side (weak side). G4 skating with (G4-P) and without (G4-NP) poling was compared in 17 elite male cross-country skiers during 4-min submaximal tests on a 2% inclined roller ski treadmill at 10, 15 and 20 km h(-1). G4-P demonstrated less ventilatory stress and higher gross efficiency compared to G4-NP at all velocities, and the blood lactate concentration was lower at the high velocity (all P ski forces, increased ski velocities and less angling and edging of the skis (all P ski forces on the strong side were lower than on the weak side with G4-P at all velocities (all P ski forces at a given work rate with G4-P demonstrate the effectiveness of poling in the G4 skating technique. Thus, poling provides possibilities to increase total propulsion, to reduce ski forces and to enhance skiing efficiency.
... Finding on Petition To List the Barndoor Skate, Winter Skate and Smooth Skate Under the Endangered Species... finding for a petition to list the ] barndoor skate (Dipturus laevis), winter skate (Leucoraja ocellata) and smooth skate (Malacoraja senta) under the Endangered Species Act (ESA). We find that the petition...
Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 5. Pressure Melting and Ice Skating / Bunsen Burner - Revisited. Classroom Volume 1 Issue 5 May 1996 pp 71-78. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/001/05/0071-0078. Resonance ...
Pesch, W. A.
Lightweight, portable, variable-speed routing skate is used on heavy metal subassemblies which are impractical to move to a stationary machine. The assembly, consisting of the housing with rollers, router, and driving mechanism with transmission, weighs about forty pounds. Both speed and depth of cut are adjustable.
In this podcast for kids, the Kidtastics talk about safety when outside, riding bikes or skating. Created: 2/2/2011 by National Center for Injury Prevention and Control (NCIPC). Date Released: 2/2/2011.
Stevenson , Duane E.; Lewis , Kristy A.
We analyzed skate catch data collected by observers in the North Pacific Groundfish Observer Program (NPGOP) from 1998 through 2008 to document recent changes in the identification of skates by observers and to examine the species composition of observed skate catch in Alaska’s groundfish fisheries as well as recent trends in skate retention by commercial fishermen. Historically, almost all skate bycatch has been reported by NPGOP observers as “skate unidentified.” However, since 2004 o...
The purpose of this thesis was to research and compare international ice hockey fans and domestic, Finnish ice hockey fans concerning the factors that motivate them to attend ice hockey events. The thesis was assigned by Sport Business School Finland. The thesis was completed as a quantitative study. The sample was gathered during 2013 and 2014. The first sample was gathered at the 2013 IIHF Ice Hockey World Championships held in Stockholm, Sweden. The respondents were spectators randomly...
Boyd, Jeffrey E.; Sayles, Maxwell; Olsen, Luke; Tarjan, Paul
We present a system for the broadcast of hockey games over the internet. The system allows users to experience the hockey game while it is in progress. Our system uses generic content description servers that acquire information from an external source, process it, and serve the processed data to client systems. Dynamic configuration of the servers allows us to use them in a variety of roles. For example, video information servers, like an MPEG-7 camera, produce XML documents that describe the motion of objects in the scene in addition to unprocessed video. Unlike an MPEG-7 camera, our video information servers interact with client systems, and can change their behavior through dynamic configuration. In an alternate configuration, a content description server acts as a game server in our hockey broadcast system. The game server forms an environment model that encapsulates the state of the hockey game and serves data from the model to clients. We developed and tested our system using a 1/32-scale model of a hockey rink. Early results using data acquired at a real rink indicate that the system performs as expected.
Wu, Wen-Lan; Hsu, Hsiu-Tao; Chu, I-Hua; Tsai, Feng-Hua; Liang, Jing-Min
In order to help coaches analyse the techniques of professional in-line speed skaters for making the required fine adjustments and corrections in their push-off work, this study analysed the specific plantar pressure characteristics during a 300-m time-trial test. Fourteen elite in-line speed skaters from the national team were recruited in this study. The total completion time of the 300-m time-trial test, duration of each skating phase, and plantar pressure distribution were measured. The correlation between plantar pressure distribution and skating performance was assessed using Pearson correlation analyses. The results showed that the contact time of the total foot and force-time integral (FTI) in the medial forefoot were significantly correlated with the duration of the start phase, and the FTIs in the medial forefoot of the gliding (left) leg and lateral forefoot of the pushing (right) leg were significantly correlated with the duration of the turning phase. The maximum force in the medial heel, medial forefoot, and median forefoot and the FTI in the medial heel and medial forefoot were significantly correlated with the duration of the linear acceleration phase. The results suggest that a correct plantar loading area and push-off strategy can enhance the skating performance.
Orenstein, J B
To determine the types of injuries sustained during the use of in-line skates and to compare them with injuries sustained during the use of roller skates and skateboards, which have similar riding mechanics; and to assess the protection afforded by wrist, elbow, and knee guards. The study population was a consecutive series of injured patients who presented to the emergency department of a Level 1 trauma center between May 1992 and October 1993. Of the 137 patients with skating injuries evaluated in the ED during the study period, 63 (46%) were in-line skaters, 36 (26%) were roller skaters, and 38 (28%) were skateboarders. Minor injuries (sprains, bruises, lacerations) were more common than fractures, and there was no statistical difference in the types of injury between skate groups (P=NS). The most common serious injury was fracture of the distal arm, which occurred in each of the three skater groups (43%, n=59). Of these patients 37% (n=21) required open or closed orthopedic reduction. More fractures of the distal forearm or elbow occurred among skaters who had not been wearing wrist guards (P=.013; risk ratio, 2.07; 95% confidence interval, 1.37 to 3.13). Only 25% of skaters used any protective equipment. In-line skaters owned and used protective equipment more often than did roller-skaters or skateboarders. Most injuries occurred while the patient was travelling in the street or on the sidewalk. Injuries occurred more commonly because the skater was going too fast (35%), because the skater struck an object in the pavement (20%), or because the skater was unable to brake (19%) than because of equipment failure (2%) or interference from motor vehicles (3%). Injuries sustained by in-line skaters were similar to those sustained by roller skaters and skateboarders. The risk of wrist or elbow fracture is greater when wrist guards are not worn.
Wall, W. A., Jr.
A real time, adaptive control, automatic welding system was developed. This system utilizes the general case geometrical relationships between a weldment and a weld skate to precisely maintain constant weld speed and torch angle along a contoured workplace. The system is compatible with the gas tungsten arc weld process or can be adapted to other weld processes. Heli-arc cutting and machine tool routing operations are possible applications.
Full Text Available Layback spin is considered as one of the most beautiful and elegant spins performed in figure skating. It is also one of the required spins in competitive short program in female category. Different techniques of executing layback spin with variations in changing the positions of free parts of the body, as well as the evaluation of layback spin in accordance with ISU rules and regulations, which have been used in all International Skating Federation competitions since 2004 (World and European championships, Olympic Games are presented in this paper. Due to very difficult position of the body while performing a layback spin, it is essential that the skaters who want to master it should have excellent agility (especially of the spinal column and shoulder and knee joints and balance. Layback spin performance requires significant skating knowledge, so it cannot be performed by beginners. Depending on the fl exibility and creativity, a skater can execute various positions of the head, arms, body and free leg while performing a layback spin. In some cases, these variations can increase the level of difficulty, and in others only the mark given for executing this spin.
Thesis explains general situation of ice hockey in Bosnia and Herzegovina, what is the current state of hockey and how did it came to the situation as well as how this situation could and should be resolved. This thesis should explain how the development of ice hockey in Bosnia should be done. Thesis main focus is on ice hockey programs and not on financial side of the development. Thesis covers all important areas of ice hockey sport such as: junior programs, junior league, men leag...
... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Skate allocation, possession, and landing... Management Measures for the NE Skate Complex Fisheries § 648.322 Skate allocation, possession, and landing provisions. (a) Allocation of TAL. (1) A total of 66.5 percent of the annual skate complex TAL shall be...
Looney, Marilyn A.
The purpose of this study was to determine if the 2010 Olympic figure skating judges had trouble scoring Plushenko and the transitions program component, and if the International Skating Union's (ISU) "corridor" method flagged the same judging anomalies as the Rasch analyses. A 3-facet (skater by program component by judge) Rasch rating…
Joseph J Bizzarro
Full Text Available Skates (Rajiformes: Rajoidei are common mesopredators in marine benthic communities. The spatial associations of individual species and the structure of assemblages are of considerable importance for effective monitoring and management of exploited skate populations. This study investigated the spatial associations of eastern North Pacific (ENP skates in continental shelf and upper continental slope waters of two regions: central California and the western Gulf of Alaska. Long-term survey data were analyzed using GIS/spatial analysis techniques and regression models to determine distribution (by depth, temperature, and latitude/longitude and relative abundance of the dominant species in each region. Submersible video data were incorporated for California to facilitate habitat association analysis. We addressed three main questions: 1 Are there regions of differential importance to skates?, 2 Are ENP skate assemblages spatially segregated?, and 3 When skates co-occur, do they differ in size? Skate populations were highly clustered in both regions, on scales of 10s of kilometers; however, high-density regions (i.e., hot spots were segregated among species. Skate densities and frequencies of occurrence were substantially lower in Alaska as compared to California. Although skates are generally found on soft sediment habitats, Raja rhina exhibited the strongest association with mixed substrates, and R. stellulata catches were greatest on rocky reefs. Size segregation was evident in regions where species overlapped substantially in geographic and depth distribution (e.g., R. rhina and Bathyraja kincaidii off California; B. aleutica and B. interrupta in the Gulf of Alaska. Spatial niche differentiation in skates appears to be more pronounced than previously reported.
Bizzarro, Joseph J; Broms, Kristin M; Logsdon, Miles G; Ebert, David A; Yoklavich, Mary M; Kuhnz, Linda A; Summers, Adam P
Skates (Rajiformes: Rajoidei) are common mesopredators in marine benthic communities. The spatial associations of individual species and the structure of assemblages are of considerable importance for effective monitoring and management of exploited skate populations. This study investigated the spatial associations of eastern North Pacific (ENP) skates in continental shelf and upper continental slope waters of two regions: central California and the western Gulf of Alaska. Long-term survey data were analyzed using GIS/spatial analysis techniques and regression models to determine distribution (by depth, temperature, and latitude/longitude) and relative abundance of the dominant species in each region. Submersible video data were incorporated for California to facilitate habitat association analysis. We addressed three main questions: 1) Are there regions of differential importance to skates?, 2) Are ENP skate assemblages spatially segregated?, and 3) When skates co-occur, do they differ in size? Skate populations were highly clustered in both regions, on scales of 10s of kilometers; however, high-density regions (i.e., hot spots) were segregated among species. Skate densities and frequencies of occurrence were substantially lower in Alaska as compared to California. Although skates are generally found on soft sediment habitats, Raja rhina exhibited the strongest association with mixed substrates, and R. stellulata catches were greatest on rocky reefs. Size segregation was evident in regions where species overlapped substantially in geographic and depth distribution (e.g., R. rhina and Bathyraja kincaidii off California; B. aleutica and B. interrupta in the Gulf of Alaska). Spatial niche differentiation in skates appears to be more pronounced than previously reported.
Cusimano, Michael D
In Canada and the USA, ice hockey is a cause of traumatic brain injury. Post-concussive symptoms are the most important feature of the diagnosis of concussion in sports and it is recommended that athletes not return to play while still symptomatic. Lack of knowledge of concussions could therefore be one of the main detriments to concussion prevention in hockey. The purpose of this research is to describe what minor league hockey players, coaches, parents and trainers know about concussion and its management. A questionnaire to assess concussion knowledge and return to play guidelines was developed and administered to players at different competitive levels (n = 267), coaches, trainers and parents (total adults n = 142) from the Greater Toronto Area. Although a majority of adults and players could identify mechanisms responsible for concussion, about one-quarter of adults and about a quarter to a half of children could not recall any symptoms or recalled only one symptom of a concussion. A significant number of players and some adults did not know what a concussion was or how it occurred. Almost half of the players and a fifth of the adults incorrectly stated that concussion was treated with medication or physical therapy. Nearly one quarter of all players did not know if an athlete experiencing symptoms of concussion should continue playing. This study demonstrated that a significant number of people held misconceptions about concussion in hockey which could lead to serious health consequences and creates a need for better preventive and educational strategies.
Carbonari, Patricia; Perrone, Raúl
Raúl Perrone muestra una vez más que no se cansa de explorar otros mundos. Como en su cine de siempre, pero sumando nuevas ideas, los pibes-adolescentes de Pendejos vagabundean en sus skates en medio de una atmósfera hostil que no los contiene. Con los protagonistas transmitiendo sus angustias en algunos pocos intertítulos, y en blanco y negro, vuelve a formas de principios del siglo XX generando un quiebre en este cine siempre personal, sin ataduras y que privilegia el camino sensorial para ...
Kelm, J; Bambach, S; Seil, R; Anagnostakos, K; Pitsch, W
Inline skating is becoming more and more popular all over the world. This results in a rapid increase in sports injuries. The aim of our study was to analyse injury patterns and injury causes as well as the influence of the social status on possessing and using protective equipment. We recorded and evaluated 76 accidents in our outpatient department by means of standardised questionnaires over a period of 18 months. We checked the direct circumstances of the accident, social situation and aspects of the family's social status. The average age of the injured person was 12.5 years. The most common injury localisations were the distal forearm (39.5 %) and the wrist (9.2 %), the most common types of injuries were fractures (51.9 %, especially upper extremity) and distortions (17.6 %). Most injuries happened in easy driving situations, like gliding, turning and braking. The injured children did not differ significantly from the general population. The willingness of children to wear special safety gear increased with the social status of their family. Learning the fundamental techniques can improve driving skills and reduce the number of injuries. Integration of skating lessons in physical education at school is desirable, especially regarding the injured person's age and would improve their willingness to wear protectors, independent of the social status.
Watura, Christopher; Harries, William
A 42-year-old female nurse presented in March 2008 with a left proximal hamstring tendon injury sustained while playing hockey. At surgery, the proximal biceps femoris tendon and semitendonosus were found to be ruptured and were repaired. The patient made a good recovery but sustained a further hockey injury in January 2010 involving a complete tear and rupture of the biceps femoris tendon distally. This was managed conservatively and the patient was able to return to playing hockey 10 months...
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 l...
Full Text Available The subject of this work was to investigate the early failure, which occurred in the chassis of a roller skate for figure skating. The paper deals with the preliminary analysis of the crack and with the integrated approach, which had to be followed to overcome the problem. Literature in the fields of physiology and biomechanics was studied to correctly simulate the load distribution on the chassis. Finite element simulation, experimental stress analysis and analytical modeling of impact phenomena had to be combined together to estimate the entity of dynamic loads and the corresponding state of stress. The analysis led to the determination of the primary cause of failure, bending fatigue, and to the suggestion of a simple solution to improve and optimize the project.
Cross, Rod; Lindsey, Crawford
An ice hockey player can strike a puck at speeds up to about 45 m/s (100 mph) using a technique known as the slap shot. There is nothing unusual about the speed, since golf balls, tennis balls, and baseballs can also be projected at that speed or even higher. The unusual part is that the player strikes the ice before striking the puck, causing the stick to slow down and to bend. If a tennis player or a golfer did something like that, by hitting the ground before hitting the ball, it would be classed as a miss-hit and the ball would probably dribble away at low speed. Nevertheless, there appears to be a significant advantage in hitting the ice before hitting the puck, otherwise hockey players would have learned from experience not to do that.
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.
Topps, David; Ellaway, Rachel; Kupsh, Christine
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.
Atwal, Sanita; Porter, Jack; MacDonald, Paul
More than 500,000 men play "gentlemen's" recreational hockey in Canada, but the safety of this exercise has not been studied. Exercising at extremes of intensity has been associated with an increased risk of cardiac events. Our objective was therefore to determine baseline cardiac risk factors among adult recreational hockey players and to measure any cardiac abnormalities they experienced while playing hockey. We assessed baseline cardiac risk factors in 113 male volunteers recruited from a recreational hockey league. Each subject underwent holter electrocardiographic monitoring before, during and after at least one hockey game (maximum of 115 holter data sets). We used the data to assess exercise heart rate, arrhythmias and ST-segment changes and for correlation with symptoms and other predictors of fitness. For all participants, maximum heart rate (HRmax) (mean 184 [standard deviation 11] beats/min) was greater than target exercise heart rate (calculated as 55% to 85% of age-predicted HRmax), and in 87 (75.6%) of the 115 holter data sets, the heart rate exceeded the age-predicted HRmax. The mean period for which heart rate exceeded 85% of the age-predicted HRmax was 30 (SD 13) min. For 80 (70.1%) of 114 data sets, heart rate recovery was poor. Nonsustained ventricular tachycardia was seen in data from 2 holter monitoring sessions and ST-segment depression in data from 15 sessions. The physical activity pattern that occurred during recreational hockey caused cardiac responses that might be dangerous to players' health. More specifically, the players exceeded target and maximum heart rates, had poor heart rate recovery after exercise, and had episodes of nonsustained ventricular tachycardia and ST-segment depression of uncertain clinical significance.
Jang, Gwang Il; Kim, Gahee; Hwang, Chung Yeon; Cho, Byung Cheol
Prokaryotes were extracted from skates and fermented skates purchased from fish markets and a local manufacturer in South Korea. The prokaryotic community composition of skates and fermented skates was investigated using 16S rRNA pyrosequencing. The ranges for pH and salinity of the grinded tissue extract from fermented skates were 8.4-8.9 and 1.6-6.6%, respectively. Urea and ammonia concentrations were markedly low and high, respectively, in fermented skates compared to skates. Species richness was increased in fermented skates compared to skates. Dominant and predominant bacterial groups present in the fermented skates belonged to the phylum Firmicutes, whereas those in skates belonged to Gammaproteobacteria. The major taxa found in Firmicutes were Atopostipes (Carnobacteriaceae, Lactobacillales) and/or Tissierella (Tissierellaceae, Tissierellales). A combination of RT-PCR and pyrosequencing for active bacterial composition showed that the dominant taxa i.e., Atopostipes and Tissierella, were active in fermented skate. Those dominant taxa are possibly marine lactic acid bacteria. Marine bacteria of the taxa Lactobacillales and/or Clostridia seem to be important in alkaline fermentation of skates. Copyright © 2016 Elsevier Ltd. All rights reserved.
López de Subijana Hernández, Cristina; Juarez Santos-Garcia, Daniel; Mallo Sainz, Javier; Navarro Cabello, Enrique
The aim of this study was to analyse the kinematic sequencing in the penalty-corner drag-flicks of elite male and female field hockey players of international calibre. Thirteen participants (one skilled male drag-flicker and six male and six female elite players) participated in the study. An optoelectronic motion analysis system was used to capture the drag-flicks with six cameras, sampling at 250 Hz. Select ground reaction force parameters were obtained from a force platform which registere...
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
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/m2) 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 optimization
Dawn P. Gill
Full Text Available Abstract Background 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. Methods 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/m2 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
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 ...
A high school hockey team is playing the last of three games in one day. The game gets rough, and the star player is slammed against the boards. Injured, he is escorted off the ice. This case follows his health as it deteriorates over the next several hours. Students are presented with the hockey player's symptoms, and they use their knowledge of…
Full Text Available The article estimates age-specific indexes of nervous system, responsible for juveniles’ speed qualities, training in Children and Youth Ice Hockey School. The received data justifies the necessity for individual approach to each hockey player, considering his age peculiarities and, respectively the functioning of the nervous system in the course of training organization.
Berlage, Gai Ingham
A survey was made of 107 fathers of boys aged 11 and 12 competing in the Pee Wee Level Division III of the Connecticut State Ice Hockey Tournament. The questionnaire was designed to examine the career aspirations of the fathers for their sons in ice hockey, and to determine their attitudes toward their son's participation in the sport as it…
Jansen, P. L.; Arias, I. M.
1. The main bilirubin conjugate in bile of spiny dogfish (Squalus Acanthias) and small skate (Raja Erinacea) is bilirubin monoglucuronide. 2. Microsomal preparations from dogfish and small skate liver have similar bilirubin UDPglucuronyltransferase (UDPGT) activity and catalyze the conjugation of
Full Text Available The purpose of this paper is to offer a conceptualization of leisure that can help us understand what constitutes as leisure and how leisure is attained in a highly regimented context such as elite hockey. Leisure researchers are unable to agree on a definition of leisure that best represents the field, which is perhaps why leisure has lost its significance within contemporary academia. In this paper, a conceptualization is provided that was developed through research on Junior level ice hockey players. Junior level hockey has a highly structured and professionalized regiment but yet, leisure is still attainable for players despite having little control over their involvement. Traditional definitions of leisure do not capture what it means to be in leisure even though theoretically Junior level hockey players are considered to be in serious leisure as amateurs. Thus, this paper can help justify and lets us understand how leisure is attained in Junior level hockey.
Lemmink, K.A.; Elferink-Gemser, M.T.; Visscher, C.
OBJECTIVES: To determine the reliability of two field hockey specific tests: the shuttle sprint and dribble test (ShuttleSDT) and the slalom sprint and dribble test (SlalomSDT). METHODS: The shuttle sprint and dribble performances of 22 young male and 12 young female field hockey players were
... United States; Northeast Skate Complex Fishery; Secretarial Emergency Action AGENCY: National Marine...: Temporary rule; emergency action. SUMMARY: This final rule increases catch limits in the Northeast skate... information that shows significant increases in the abundance of skates, and are intended to provide a...
Skates have recently become a small commercial fishery in Alaska and along the western United States coast. Most of the skate byproduct is discarded or made into meal; therefore, there is opportunity to enhance the utilization for skate byproducts. The objective of this research project was to chemi...
... United States; 2012-2013 Northeast Skate Complex Fishery Specifications AGENCY: National Marine Fisheries.... SUMMARY: This rule implements catch limits and associated measures for the Northeast skate complex fishery... Council pursuant to the provisions of the Northeast Skate Complex Fishery Management Plan. The catch...
... Economic Zone Off Alaska; Skates Management in the Groundfish Fisheries of the Bering Sea and Aleutian... skates from the ``other species'' category to the ``target species'' category in the FMP. Amendments 96... would add skate species to the reporting codes for the BSAI groundfish fisheries. This proposed action...
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.
Til Pérez, Lluís; Barceló Peiró, Oriol; Pomés Díes, Teresa; Martínez Navas, Roberto; Galilea Ballarini, Pedro; Bellver Vives, Montserrat
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....
Hoff, G R
Predation on skate eggs by snails was examined for three skate species at seven nursery sites in three regions (north, middle and south) of the eastern Bering Sea. Mean predation levels were 6.46% for the Alaska skate Bathyraja parmifera, 2.65% for the Aleutian skate Bathyraja aleutica and 22.25% for the Bering skate Bathyraja interrupta. Predation levels were significantly higher at the middle and north sites than the south sites for all species combined. Predation levels decreased with increasing egg-case densities at all nursery sites, and the highest predation levels occurred where egg-case densities were very low. Predated egg-case density increased with increasing snail densities across all nursery sites examined. The Oregon triton Fusitriton oregonensis was the most abundant snail species at all nursery sites and displayed ability to drill holes in the egg case of B. parmifera. Holes left by predatory snails in egg cases of B. parmifera were significantly larger, and of different shape at the middle site compared to the south site. Holes in B. parmifera were also significantly larger than those in egg cases of B. interrupta across all sites examined. Egg cases of B. aleutica possess surface spines that cover the egg case and may inhibit predation by snails at a greater rate than that of the B. parmifera and B. interrupta, which have a smoother egg-case surface.
Clark, J Michio; Post, Andrew; Hoshizaki, T Blaine; Gilchrist, Michael D
In ice hockey, concussions can occur as a result of many different types of impact events, however hockey helmets are certified using a single injury scenario, involving drop tests to a rigid surface. The purpose of this study is to measure the protective capacity of ice hockey helmets for different impact events in ice hockey. A helmeted and unhelmeted Hybrid III headform were impacted simulating falls, elbow, shoulder and puck impacts in ice hockey. Linear and rotational acceleration and maximum principal strain (MPS) were measured. A comparison of helmeted and unhelmeted impacts found significant differences existed in most conditions (p 0.05). Impacts to the ice hockey helmet tested resulted in acceleration levels below reported ranges of concussion and TBI for falls up to 5 m/s, elbow collisions, and low velocity puck impacts but not for shoulder collisions or high velocity puck impacts and falls. The helmet tested reduced MPS below reported ranges of concussion and TBI for falls up to 5 m/s but not for the other impact events across all velocities and locations. This suggests that the ice hockey helmet tested is unable to reduce engineering parameters below reported ranges of concussion and TBI for impact conditions which do not represent a drop against a rigid surface.
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.
This project-oriented thesis is based on the fact, that Naerbo Idrettslag has not had any guidelines or a manual on how the club wants to develop the ice hockey players. The basic idea and aim of the manual is to collect all the essential information about ice hockey and coaching in one manual. This manual is targeted for ice hockey coaches and players’ parents working around the Naerbo Idrettslag, Norway. Since the club is hobby-based, the purpose is to provide an easy to read manua...
Coaching in hockey has changed in direction from coach-centered coaching to player-centered coaching. Nowadays it is more holistic; it is not just coaching tactics and trying to win games at all costs. The way of thinking has changed; instead of the former “what does a team need” way of thinking, nowadays it is more important to ask, “What does an individual need?” This thesis has been written for EPS Hockey E2-C2 juniors and E2-C2 coaches. The Executive Manager of EPS Hockey requested...
Pitkänen, Krista; Turunen, Tuuli
The purpose of the research conducted at the World Championships in Helsinki 2012 and in Stock-holm 2013 was to explore the values of ice hockey fans and their image of ice hockey. This thesis was assigned by the Sport Business School Finland. Another purpose was to find out if there are dif-ferences or similarities between the values and ice hockey image of the Finnish and foreign re-spondents, and between the Finnish and Swedish respondents. Quantitative and qualitative research methods...
Buchheit, Martin; Lefebvre, Benjamin; Laursen, Paul B; Ahmaidi, Said
The purpose of this study was to examine the reliability, usefulness, and validity of the 30-15 Intermittent Ice Test (30-15(IIT)) in 17 young elite ice hockey players. For the reliability and usefulness study, players performed the 30-15(IIT) 7 days apart. For the validity study, data derived from the first 30-15(IIT) were compared with those obtained from the 30-15 Intermittent Fitness Test (30-15(IFT), the running version of this test used as a reference marker for its ability to assess cardiovascular fitness in the field, that is, VO₂peak). Maximal speed, heart rate at exhaustion (HR(peak)) and postexercise blood-lactate levels ([La](b)) were collected for all tests, whereas submaximal HR was taken at stages 4 and 8 (HR(stage4) and HR(stage8)) during the 30-15(IIT). All intra-class correlation coefficients were >0.94. Coefficients of variation were 1.6% (90% CI, 1.3-2.3), 1.7% (1.3-2.8), 1.4% (1.0-2.2), and 0.7% (0.5-1.1) for maximal skating speed, HR(stage4), HR(stage8), and HR(peak), respectively. Correlations between maximal velocities and HR(peak) obtained for the 30-15(IIT) vs. 30-15(IFT) were very large (r = 0.72) and large (r = 0.61), respectively. Maximal skating speed was also largely correlated to estimated VO₂peak (r = 0.71). There was however no correlation for [La](b) values between both tests (r = 0.42). These results highlight the specificity of the on-ice 30-15(IIT) and show it to be a reliable and valid test for assessing cardiorespiratory fitness in young elite players. Coaches could interpret a change in performance of at least 2 stages, or a change in submaximal HR of more than 8% (≈8 b·min⁻¹) during the eighth stage to be a meaningful change in skating fitness.
Linzmeier, Kathleen A.; LaBella, Cynthia R.
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.
Kontos, Anthony P; Elbin, R J; Sufrinko, Alicia; Dakan, Scott; Bookwalter, Kylie; Price, Ali; Meehan, William P; Collins, Michael W
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.
Macnow, Theodore; Mannix, Rebekah; Meehan, William P
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 electric group (2.8% vs 1%, P = 0.01). There were no significant differences in symptom scores. Players at arenas operating IC resurfacers had significantly higher SpCO levels. Youth hockey players in arenas with IC resurfacers have an increase in 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.
van der Eb, Jeroen; Zandee, Willem; van den Bogaard, Timo; Geraets, Sjoerd; Veeger, H.E.J.; Beek, Peter; Potthast, Wolfgang; Niehoff, Anja; David, Sina
The aim of the current study is to evaluate several performance indicators to be used as real-time feedback in the coming experiments to enhance performance of elite speeds skaters. Six speed skaters, wearing one IMU per skate, collected data over one full training season to evaluate and pinpoint
Bradley, Graham L.
All people influence, and are influenced by, the contexts they inhabit. Leisure contexts are no exception. The current research comprised three studies investigating the links between one leisure context, skate parks, and adolescent development. Using interview, observation, and questionnaire methods, the research shed light on several of the…
Forces are at work all around us. Discover what a force is, and different kinds of forces that work on contact and at a distance. We use simple language and vocabulary to make this invisible world easy for students to ""see"" and understand. Examine how forces ""add up"" to create the total force on an object, and reinforce concepts and extend learning with sample problems.
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...
Examines the construction of community on a women's ice hockey team, using data from fieldwork and interviews with one Canadian team. Results indicated that the locker room provided a space where players came together as hockey players and women. A common focus on hockey united the diverse group. (SM)
Woodcock, Amy Terhaar
Reports a study that compared the newspaper coverage of girls' and boys' high school hockey teams in Minnesota from November 1994 to March 1995. Researchers coded each newspaper article for sex, length, and photo types. Results indicated that boys' high school hockey received much more newspaper coverage than girls' high school hockey. (SM)
Biasca, N; Simmen, H P; Bartolozzi, A R; Trentz, O
Ice hockey is considered to be one of the fastest and roughest of all sports. Prospective injury reports of the North American National Hockey League, the Canadian Amateur Hockey Association and of several European teams (UdSSR, CSSR, Sweden and Switzerland) are reviewed to evaluate the patterns, anatomic locations, circumstances and sequelae of ice hockey-related injuries. Although different injury reporting systems are used in North America and Europe, knee injuries (sprains of the collateral ligaments) accounted for the majority of games missed (40%), followed by injuries to the shoulder (dislocation, acromio-clavicular joint separation, rotator cuff strain and tears, 20%), the groin (15%), and the back (10%). Mandatory helmets and face masks reduced the number of facial and eye injuries to a quarter from 1972 to 1983. The frequency of only concussion but also cervical spine lesions is increasing. The prevention of head, face, eye and neck injuries should mainly be accomplished by enforcement of current rules (mandatory helmets with face masks) and institution of new rules. Improvement in protective equipment would also have the effect of decreasing the frequency of injuries. Ice hockey is the fastest team sport and involves both finesse and controlled aggression. It is also considered to be one of the roughest of all sports. In recent years, ice hockey has grown tremendously in popularity, not only in the United States and in Canada but also in many European countries . The number of both professional and amateur hockey players has increased with the expanding interest in the sport around the world .(ABSTRACT TRUNCATED AT 250 WORDS)
Home advantage is a well-documented phenomenon in many sports. Home advantage has been shown to exist for team sports (soccer, hockey, football, baseball, basketball) and for countries organizing sports tournaments like the Olympics and World Cup Soccer. There is also some evidence for home
Pitkin, M; Shcherbina, K; Smirnova, L; Suslyaev, V; Zvonareva, E; Kurdibaylo, S
The first ever ice hockey team of transtibial amputees playing in a standing position was established in St. Petersburg in 1999 under the program "US-Russian Prosthetic Rehabilitation Bridge" . Nowadays, Canada, Russia, USA, Finland, Czech Republic and Latvia have their national associations, two World Championships were conducted (2003 - Kiisakalio, Finland; 2004 - Prague, Czech Republic), and the International Standing Ice Hockey Federation (ISIHF) was formed. Players from the former Yugoslav states, Estonia, Sweden, Israel, and Australia are very active in attempts to form the teams in their countries. Beyond the tournaments, players have participated in many professional conventions and other public events in support of international assistance to landmine victims and rehabilitation of children worldwide. The ISPO has been supportive in disseminating information and knowledge in amputee hockey, providing an opportunity for a demonstration game at the 2004 World Congress in Hong Kong (Figure 1).
Muehlbauer, Thomas; Schindler, Christian; Panzer, Stefan
Data from speed skating during World Cup 1,500-m middle-distance races were analyzed to (a) determine the time/velocity distribution during the race and (b) assess the impact of time spent in several race sectors on performance outcome. Absolute and relative sector times for the first 300 m (S1) and the following three 400-m laps (S2-S4) and their…
MacCormick, Lauren; Best, Thomas M.
Background: Men’s ice hockey allows for body checking, and women’s ice hockey prohibits it. Studies have reported injury data on both sexes, but no systematic reviews have compared the injury patterns between male and female ice hockey players. Hypothesis: Men’s and women’s ice hockey would have different types of injuries, and this difference would extend across the different age groups and levels of play. Study Design: Systematic review; Level of evidence, 4. Methods: Three databases, 3 scientific journals, and selected bibliographies were searched to identify articles relevant to this study. Articles were further screened by the use of predetermined inclusion and exclusion criteria. Twenty-two studies met these criteria and were subsequently reviewed. Results: Men sustained higher rates of injuries than women at all age levels, and both sexes sustained at least twice as many injuries in games than practices. Both sexes sustained most of their injuries from player contact. Men and women in college sustained most injuries to the head and face, and women suffered from higher percentages of concussion. At all ages and levels of play, men had higher rates of upper extremity injuries (shoulder), while women were found to sustain more injuries to the lower extremity (thigh, knee). Conclusion: Although findings showed men sustaining higher rates of injuries than women, the predominant mechanism of player contact was the same. The most common locations and types of injuries in female ice hockey players are comparable to other sports played by women, and similar interventions could offer protection against injury. Clinical Relevance: Further studies that report injury data for women playing ice hockey at all levels will assist in understanding what prevention strategies should be implemented. PMID:26535265
Brian P. Tierney
Full Text Available A surgical technique using local tissue skate flaps combined with cylinders made from a naturally derived biomaterial has been used effectively for nipple reconstruction. A retrospective review of patients who underwent nipple reconstruction using this technique was performed. Comorbidities and type of breast reconstruction were collected. Outcome evaluation included complications, surgical revisions, and nipple projection. There were 115 skate flap reconstructions performed in 83 patients between July 2009 and January 2013. Patients ranged from 32 to 73 years old. Average body mass index was 28.0. The most common comorbidities were hypertension (39.8% and smoking (16.9%. After breast reconstruction, 68.7% of the patients underwent chemotherapy and 20.5% underwent radiation. Seventy-one patients had immediate breast reconstruction with expanders and 12 had delayed reconstruction. The only reported complications were extrusions (3.5%. Six nipples (5.2% in 5 patients required surgical revision due to loss of projection; two patients had minor loss of projection but did not require surgical revision. Nipple projection at time of surgery ranged from 6 to 7 mm and average projection at 6 months was 3–5 mm. A surgical technique for nipple reconstruction using a skate flap with a graft material is described. Complications are infrequent and short-term projection measurements are encouraging.
... Economic Zone Off Alaska; Skates in the Bering Sea and Aleutian Islands Management Area AGENCY: National...: Temporary rule; closure. SUMMARY: NMFS is prohibiting retention of skates in the Bering Sea and Aleutian... skates in the BSAI has been reached. DATES: Effective 1200 hrs, Alaska local time (A.l.t.), September 24...
... Economic Zone Off Alaska; Skate Management in the Groundfish Fisheries of the Bering Sea and Aleutian... referred to as ``the FMPs''). Amendment 95 moves skates from the ``other species'' category to the ``target... specifications and adds skate species to the reporting codes for the BSAI groundfish fisheries. This action is...
... Economic Zone Off Alaska; Big Skate in the Central Regulatory Area of the Gulf of Alaska AGENCY: National...: Temporary rule; closure. SUMMARY: NMFS is prohibiting retention of big skate in the Central Regulatory Area... skate in the Central Regulatory Area of the GOA has been reached. DATES: Effective 1200 hrs, Alaska...
... Economic Zone Off Alaska; Longnose Skate in the Western Regulatory Area of the Gulf of Alaska AGENCY.... ACTION: Temporary rule; closure. SUMMARY: NMFS is prohibiting retention of longnose skate in the Western... (TAC) of longnose skate in the Western Regulatory Area of the GOA has been reached. DATES: Effective...
... Economic Zone Off Alaska; Big Skate in the Central Regulatory Area of the Gulf of Alaska AGENCY: National...: Temporary rule; closure. SUMMARY: NMFS is prohibiting retention of big skate in the Central Regulatory Area... big skate in the Central Regulatory Area of the GOA has been reached. DATES: Effective 1200 hrs...
... Economic Zone Off Alaska; Skates Management in the Bering Sea and Aleutian Islands Management Area..., Amendment 95 would move skates from the other species category to the target species category in the FMP for... the Secretary, this amendment would move the skates group from the ``other species'' category to the...
... Economic Zone Off Alaska; Big Skate in the Central Regulatory Area of the Gulf of Alaska AGENCY: National...: Temporary rule; closure. SUMMARY: NMFS is prohibiting retention of big skate in the Central Regulatory Area... skate in the Central Regulatory Area of the GOA has been reached. DATES: Effective 1200 hrs, Alaska...
Fogel Curtis A.
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.
Full Text Available Postural stability is one of latent factors affecting game performance of an individual to a certain extent. The presented study deals with monitoring changes of postural stability in ice hockey players after eight week’s balance training. The screened sample consisted of junior category ice hockey players divided into experimental (n = 8 and reference groups (n = 8. Postural stability was measured using a stabilographic method on the AMTI AccuSwayPLUS force platform. The level of postural stability was assessed in three tests, namely bipedal stance with and without sight control and bipedal stance with reduced proprioception using the parameters of 95% confidence ellipse, path of CoP and mean velocity of CoP. The level of monitored stability parameters did not indicate any significant differences between the groups in any of the tests at the level of significance α = 0.05. Comparing postural stability of the experimental group between pre-test and post-test showed significant differences in the test without sight control and the test with reduced proprioception in lCoP and vCoP parameters (Z = 2.1004; α ˂ 0.05. Regarding the reference group, no significant changes of the level of postural stability between the pre-test and post-test were found in any of the parameters (Z = 0.3652 to 1.8257; α ˃ 0.05.
... based on abundance indices in the NMFS Northeast Fisheries Science Center bottom trawl survey. Amendment... skate wings (11,350 lb (5,148 kg) whole weight) per trip for the skate wing fishery, and an AM that... (1,135 lb (515 kg) whole weight) when 80 percent of the TAL for the wing fishery is reached. In FY...
... indices in the NMFS Northeast Fisheries Science Center bottom trawl survey. Amendment 3 to the Skate FMP...,350 lb (5,148 kg) whole weight) per trip for the skate wing fishery, and an AM that further reduces... (515 kg) whole weight) when 80 percent of the TAL for the wing fishery is reached. In FY 2010, the...
Kamst, Richard; Kuper, Gerard H.; Sierksma, Gerard; Talsma, Bertus G.
During the Olympic Games and the World Championships Single Distances the 1000m is skated by every skater only one time. However, there may be a difference in skating a 1000m race with a start in the inner and the outer lane that introduces an externality that introduces unfairness. We show that
Skates have recently become a small commercial fishery in Alaska and along the western United States coast, but have long been associated with bycatch. The fins are marketed as "skate wings" and mainly sold fresh, frozen, and dried or salted and dehydrated for Asian markets. Byproducts generated inc...
Kamst, Richard; Kuper, Gerard H.; Sierksma, Gerard
In 1998, the International Skating Union and the International Olympic Committee decided to skate the 500-m twice during World Single Distances Championships, Olympic Games, and World Cups. The decision was based on a study by the Norwegian statistician N. L. Hjort, who showed that in the period
Camperi, Marcelo; Tricas, Timothy C; Brown, Brandon R
Morphology typically enhances the fidelity of sensory systems. Sharks, skates, and rays have a well-developed electrosense that presents strikingly unique morphologies. Here, we model the dynamics of the peripheral electrosensory system of the skate, a dorsally flattened batoid, moving near an electric dipole source (e.g., a prey organism). We compute the coincident electric signals that develop across an array of the skate's electrosensors, using electrodynamics married to precise morphological measurements of sensor location, infrastructure, and vector projection. Our results demonstrate that skate morphology enhances electrosensory information. Not only could the skate locate prey using a simple population vector algorithm, but its morphology also specifically leads to quick shifts in firing rates that are well-suited to the demonstrated bandwidth of the electrosensory system. Finally, we propose electrophysiology trials to test the modeling scheme. PMID:17571918
Lyons, Kady; Adams, Douglas H
Although exploited populations of elasmobranchs may be able to recover from fishing pressure, there is little information regarding the Barndoor Skate's ability to cope with other anthropogenic stressors such as organic contaminants (OCs). Legacy OCs were measured in liver, muscle and ova from fourteen Barndoor Skates with mature skates having significantly greater mean concentrations of OCs than immature skates, demonstrating bioaccumulation with age. Using Toxic Equivalency Factors, skates were found to have levels of PCBs that have been shown to elicit negative physiological responses in other fishes and these results highlight the need for future studies to investigate the potential impacts that bioaccumulated organic contaminants have on the recovery and conservation of this vulnerable species. Copyright © 2017 Elsevier Ltd. All rights reserved.
Full Text Available Morphology typically enhances the fidelity of sensory systems. Sharks, skates, and rays have a well-developed electrosense that presents strikingly unique morphologies. Here, we model the dynamics of the peripheral electrosensory system of the skate, a dorsally flattened batoid, moving near an electric dipole source (e.g., a prey organism. We compute the coincident electric signals that develop across an array of the skate's electrosensors, using electrodynamics married to precise morphological measurements of sensor location, infrastructure, and vector projection. Our results demonstrate that skate morphology enhances electrosensory information. Not only could the skate locate prey using a simple population vector algorithm, but its morphology also specifically leads to quick shifts in firing rates that are well-suited to the demonstrated bandwidth of the electrosensory system. Finally, we propose electrophysiology trials to test the modeling scheme.
Our walking and running movement patterns require friction between shoes and ground. The surface of ice is characterised by low friction in several naturally occurring conditions, and compromises our typical locomotion pattern. Ice skates take advantage of this slippery nature of ice; the first ice skates were made more than 4000 years ago, and afforded the development of a very efficient form of human locomotion. This review presents an overview of the physics of ice surface friction, and discusses the most relevant factors that can influence ice skates' dynamic friction coefficient. It also presents the main stages in the development of ice skating, describes the associated implications for exercise physiology, and shows the extent to which ice skating performance improved through history. This article illustrates how technical and materials' development, together with empirical understanding of muscle biomechanics and energetics, led to one of the fastest forms of human powered locomotion.
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…
Gilenstam, K; Karp, S; Henriksson-Larsén, K
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.
Blanchard, Bradford M.; Castaldi, Cosmo R.
Reviews the nature and frequency of injuries in youth hockey (which range from musculoskeletal injuries to life-threatening emergencies). Overall injury rates have decreased, but there is an increase in head, neck, and spine injuries. Those injuries that are serious demand prompt, skillful attention. A comprehensive format for on-ice management is…
Coelho-E-Silva, Manuel J.; Vaz, Vasco; Simoes, Filipe; Carvalho, Humberto M.; Valente-Dos-Santos, Joao; Figueiredo, Antonio J.; Pereira, Vanildo; Vaeyens, Roel; Philippaerts, Renaat; Elferink-Gemser, Marije T.; Malina, Robert M.
Characteristics of 32 international and 41 local under-17 (U-17) (14.516.5 years) roller hockey players were considered in the context of discrimination by competitive level using training history, anthropometry, skeletal maturation, and several laboratory and field performance tests. More
Kea, J; Kramer, J; Forwell, L; Birmingham, T
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.
Wimshurst, Z L; Sowden, P T; Wright, M
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.
Juhn, Mark S; Brolinson, Per Gunnar; Duffey, Timothy; Stockard, Alan; Vangelos, Zenos A; Emaus, Erik; Maddox, Matthew; Boyajian, Lori; Henehan, Michael
Ice hockey is a sport enjoyed by many men and women at the spectator and participant level. It is played with high intensity and often involves body contact. Although the women's games is far from injury free, it is the men's game that has drawn criticism for excessive violence. Much attention has been drawn to the serious injuries that have occurred in ice hockey, specifically spinal injuries, concussions, and eye injuries. Many such injuries are the result of illegal and violent acts such as checking from behind or a deliberate high stick. Because of this, some medical organizations have called for changes in the sport, such as minimum age requirements for body-checking. As a practical matter such changes are unlikely to be accepted by hockey governing boards. Many of those involved in the sport consider body-checking a fundamental component of the game. Furthermore, a distinction needs to be made between any kind of injury and a serious, catastrophic injury. For example, although a recent study found that body-checking accounted for up to 38% of ice hockey injuries, none were of the catastrophic type. With respect to catastrophic injuries such as spinal cord trauma or a blinded eye, legal body-checking accounts for significantly less than illegal body-checking (e.g., checking from behind) or violent stick work. To reduce serious injury in ice hockey, we offer 10 recommendations, key among them automatic game suspensions for certain rules violations, and recognition of the coach as the most important figure in promoting a clean, safe game.
Zayed, Mohamed A; McDonald, Joey; Tittley, Jacques G
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.
Winter, A; Pompert, J; Arkhipkin, A; Brewin, P E
Observer data from the commercial fishery on the Patagonian shelf and slope around the Falkland Islands (home to an assemblage of >16 skate species (Rajiformes), for which commercial catches have been recorded since 1987), as well as survey data from an area closed to skate target fishing after exploitation, were summarized by species to examine changes in the population status of individual skate species. Total skate catch per unit effort increased significantly in the target fishery since 1994, and four species have made up >85% of all skate catch. Bathyraja brachyurops and Zearaja chilensis increased significantly in catch proportions and abundance from 1994 to 2013. Bathyraja albomaculata and Bathyraja griseocauda decreased significantly before rebounding with trends of increasing abundance. Concurrently, B. brachyurops and Z. chilensis showed decreasing trends in size at 50% maturity in areas where skates continue to be targeted commercially. The increasing abundances and concomitant reductions in size at maturity of B. brachyurops and Z. chilensis suggest either plasticity in life-history traits or a density-dependent growth response to fishing pressure. Bathyraja griseocauda decreased in size at 50% maturity in the area that was closed to skate target fishing, where it was initially larger, but only decreased to the same average size as in the commercially targeted areas. Bathyraja albomaculata and Z. chilensis are IUCN-listed as vulnerable and B. griseocauda is listed as endangered, but their abundance trends since 1994 indicate that these populations are not declining in Falkland waters. © 2015 The Fisheries Society of the British Isles.
Zeglinksi, C M; Swanson, S C; Self, B P; Greenwald, R M
The electromyographic (EMG) activity of seven muscles of the trunk and lower extremity in five male masters level ski racers during a slalom turn in both alpine skiing and in-line skating was recorded using a telemetry system. Measurements were made on separate testing days using slopes commonly used in each activity (24 slope alpine skiing, 5 in-line skating). Qualitative video recorded at 60 Hz was analyzed to partition the turning cycle in both slalom skiing and in-line skating into initiation and turning phases. The EMG data from each turning cycle were normalized to standard isometric contractions (SIC's) for each muscle in order to quantitatively compare the amplitude characteristics of each phase of the turning cycle in both slalom skiing and in-line skating. The turning phase of in-line skating was found to be significantly longer (55%) than in slalom skiing, most likely due to significantly lower subject velocities recorded during in-line skating (8.5 m/s vs 10.2 m/s). All muscles were active at moderate to high levels (48-172% of SIC) during each phase of the turning cycle in both slalom skiing and in-line skating. The EMG amplitude characteristics were similar for six of the muscles in both slalom skiing and in-line skating for each of the turning phases. Only the erector spinae displayed significantly higher average and peak amplitudes in slalom skiing for both phases. It is concluded that the muscle activity patterns associated with the slalom turn of in-line skating are similar but notably more quasi-static than in slalom skiing.
Leiter, Jeff R; Cordingley, Dean M; MacDonald, Peter B
Ice hockey is a physiologically complex sport requiring aerobic and anaerobic energy metabolism. College and professional teams often test aerobic fitness; however, there is a paucity of information regarding aerobic fitness of elite youth players. Without this knowledge, training of youth athletes to meet the standards of older age groups and higher levels of hockey may be random, inefficient, and or effective. Therefore, the purpose of this study was to determine the aerobic fitness of elite youth hockey players. A retrospective database review was performed for 200 male AAA hockey players between the ages of 13 and 17 (age, 14.4 ± 1.2 years; height, 174.3 ± 8.5 cm; body mass, 67.2 ± 11.5 kg; body fat, 9.8 ± 3.5%) before the 2012-13 season. All subjects performed a graded exercise test on a cycle ergometer, whereas expired air was collected by either a Parvo Medics TrueOne 2400 or a CareFusion Oxycon Mobile metabolic cart to determine maximal oxygen consumption (V[Combining Dot Above]O2max). Body mass, absolute V[Combining Dot Above]O2max, and the power output achieved during the last completed stage increased in successive age groups from age 13 to 15 years (p ≤ 0.05). Ventilatory threshold (VT) expressed as a percentage of V[Combining Dot Above]O2max and the heart rate (HR) at which VT occurred decreased between the ages of 13 and 14 years (p ≤ 0.05), whereas the V[Combining Dot Above]O2 at which VT occurred increased from the age of 14-15 years. There were no changes in relative V[Combining Dot Above]O2max or HRmax between any successive age groups. The aerobic fitness levels of elite youth ice hockey players increased as players age and mature physically and physiologically. However, aerobic fitness increased to a lesser extent at older ages. This information has the potential to influence off-season training and maximize the aerobic fitness of elite amateur hockey players, so that these players can meet standards set by advanced elite age groups.
Ross, James R; Bedi, Asheesh; Stone, Rebecca M; Sibilsky Enselman, Elizabeth; Kelly, Bryan T; Larson, Christopher M
This study aimed to characterize the radiographic deformity observed in a consecutive series of butterfly goalies with symptomatic mechanical hip pain and to use computer-based software analysis to identify the location of impingement and terminal range of motion. We also compared these analyses to a matched group of positional hockey players with symptomatic femoroacetabular impingement (FAI). A consecutive series of 68 hips in 44 butterfly-style hockey goalies and a matched group of 34 hips in 26 positional hockey players who underwent arthroscopic correction for symptomatic FAI were retrospectively analyzed. Each patient underwent preoperative anteroposterior (AP) and modified Dunn lateral radiographs and computed tomography (CT) of the affected hips. Common FAI measurements were assessed on plain radiographs. Patient-specific, CT-based 3-dimensional (3D) models of the hip joint were developed, and the femoral version, alpha angles at each radial clock face position, and femoral head coverage were calculated. Maximum hip flexion, abduction, internal rotation in 90° flexion (IRF), flexion/adduction/internal rotation (FADIR), and butterfly position were determined, and the areas of bony collision were defined. Butterfly goalies had an elevated mean alpha angle on both AP (61.3°) and lateral radiographs (63.4°) and a diminished beta angle (26.0°). The mean lateral center-edge angle (LCEA) measured 27.3° and acetabular inclination was 6.1°. A crossover sign was present in 59% of the hips. The maximum alpha angle on the radial reformatted computed tomographic scan was significantly higher among the butterfly goalies (80.9° v 68.6°; P hockey goalies have a high prevalence of FAI, characterized by a unique femoral cam-type deformity and noted by an elevated alpha angle and loss of offset, which is greater in magnitude and more lateral when compared with that in positional hockey players. Associated acetabular dysplasia is also common among hockey goalies. Level
Kim, Hyeyoung; Hwang, SuJin; Lee, Byoung-Hee
[Purpose] To investigate sports injuries in Korean national ice hockey players by surveying parts, times, types, frequency, cure, and prevention types of sports injuries and provide basic data for injury prevention and performance improvement of ice hockey players. Another purpose of this study was to evaluate the incidence of ice hockey injuries according to age and the relationship between etiological factors and injuries in high school students. [Subjects and Methods] This was a cross-sect...
Berglind, Aku; Niss, David
Ice hockey is a heavily male dominated sport generally considered rough and demanding. The purpose of this quantitative study is to examine and describe the residing attitudes and norms amongst young ice hockey players utilizing the social constructivism theory and a univariate method of analysis. This has been done through the distribution of surveys consisting of a number of questions aimed to investigate the residing attitudes and expectations of young ice hockey players. To do this, we ha...
Lenamar Fiorese Vieira
Full Text Available Este estudo teve como objetivo investigar a prevalência do estado de fluxo em praticantes de escalada e skate downhill. Foram sujeitos 37 praticantes. Como instrumentos foram utilizadas a Escala de Motivação para o Esporte (SMS e a Ficha de Percepção de Capacidade de Realização da Tarefa. A coleta foi realizada nos locais de prática das atividades. Para análise dos dados foram utilizados Shapiro-Wilk, Mann-Whitney e Anova one-way. Os resultados demonstraram: 4,54% dos praticantes de escalada e 13,33% de skate downhill atingiram os elementos do estado de fluxo; a maioria dos praticantes situou-se entre a fase de fluxo estados de ansiedade ou relaxamento e exaltação ou controle; o tempo de prática contribuiu para atingir metas e estado de fluxo. Concluiu-se: o estado de Fluxo teve baixa incidência nos praticantes, havendo interferência da falta de equilíbrio entre percepção das metas, habilidades e desafios nas atividades de aventura.This study aimed to investigate the prevalence of Flow state in climbing and skate downhill practitioners. The subjects were 37 practitioners. The instruments used were the Sport Motivations Scale (SMS and Perception Capacity Achievement Task Form. Data collection was performed at the locations of these practice activities. For data analysis it was used the Shapiro-Wilk, Mann-Whitney and Anova one-way. The results showed: 4,54% of climbing practitioners and 13,33% of skate-downhill reached flow state elements; most of practitioners prevailed between the flow phase of anxiety or relaxation and phase of exaltation or control; and the practice time contributed to reach goals and Flow State. It was concluded that the Flow State had low prevalence in practitioners with interference of lack of balance between the perception of the goals, skills and challenges in the adventure activities.
Dowdall, M J; Ellis, J M; Nguyen thi Man; Morris, G E
Monoclonal antibodies against human dystrophin have been used to demonstrate the existence of a dystrophin-like protein in the electrocytes of skate electric organ. This protein is also present in skate muscle and resembles that found in Torpedo electric organ. Monoclonal antibodies against a human autosomal homologue of dystrophin (DMDL protein) did not detect a similar protein in skate or Torpedo. Immunocytochemical staining of the innervated and non-innervated faces of the electrocyte membrane was obtained using the anti-dystrophin antibodies only.
Bord, Stacey; Sidener, Tina M; Reeve, Kenneth F; Sidener, David W
The present study used a multi-component intervention package to teach on-task rollerblading and ice-skating to a boy with autism. Intervention consisted of response prompts, stimulus prompts, multiple-exemplar training, and a conditioned reinforcement system. The participant learned to remain on-task while rollerblading in a circular route marked by cones for up to 26 min. Both stimulus and response generalization of skating were demonstrated in a variety of non-training settings, including ice-skating at a rink.
Wong, Chee Kit; Jordan, Kimberlee; King, Marcus
Upper limb paresis after stroke greatly affects the performance of Activities of Daily Living (ADL). Unfortunately, rehabilitation for upper limb impairment can have poor results. The current robot-assisted devices are expensive and not readily accessible for homecare. This paper presents the development of a low-cost tabletop robotic device for upper limb rehabilitation. Conceptually, patients perform computer-based goal-directed tasks using the robotic platform. Their progress is monitored and intervention, in the form of assistance or resistance, is introduced accordingly. A prototype platform is described. Experiments demonstrate the ability of the device to provide the necessary forces during movement exercises, in relation to task completion progress, device and target location. Appropriate exercises need to be developed before clinical trials can proceed. © 2011 CROWN
Di Santo, Valentina; Tran, Anna H.; Svendsen, Jon C.
Although fish population size is strongly affected by survival during embryonic stages, our understanding of physiological responses to environmental stressors is based primarily on studies of post-hatch fishes. Embryonic responses to acute exposure to changes in abiotic conditions, including increase in hypoxia, could be particularly important in species exhibiting long developmental time, as embryos are unable to select a different environment behaviourally. Given that oxygen is key to metabolic processes in fishes and aquatic hypoxia is becoming more severe and frequent worldwide, organisms are expected to reduce their aerobic performance. Here, we examined the metabolic and behavioural responses of embryos of a benthic elasmobranch fish, the little skate (Leucoraja erinacea), to acute progressive hypoxia, by measuring oxygen consumption and movement (tail-beat) rates inside the egg case. Oxygen consumption rates were not significantly affected by ambient oxygen levels until reaching 45% air saturation (critical oxygen saturation, Scrit). Below Scrit, oxygen consumption rates declined rapidly, revealing an oxygen conformity response. Surprisingly, we observed a decoupling of aerobic performance and activity, as tail-beat rates increased, rather than matching the declining metabolic rates, at air saturation levels of 55% and below. These results suggest a significantly divergent response at the physiological and behavioural levels. While skate embryos depressed their metabolic rates in response to progressive hypoxia, they increased water circulation inside the egg case, presumably to restore normoxic conditions, until activity ceased abruptly around 9.8% air saturation. PMID:27293746
Caron, Jeffrey G; Bloom, Gordon A; Johnston, Karen M; Sabiston, Catherine M
The purpose of this study was to understand the meanings and lived experiences of multiple concussions in professional hockey players using hermeneutic, idiographic, and inductive approaches within an interpretative phenomenological analysis. The interviewer was an athlete who had suffered multiple concussions, and the interviewees were five former National Hockey League athletes who had retired due to medically diagnosed concussions suffered during their careers. The men discussed the physical and psychological symptoms they experienced as a result of their concussions and how the symptoms affected their professional careers, personal relationships, and quality of life. The former professional athletes related these symptoms to the turmoil that is ever present in their lives. These findings are of interest to athletes, coaches, sport administrators, family members, sport psychology practitioners, and medical professionals, as they highlight the severity of short- and long-term effects of concussions.
Blome, Jamie; Waldron, Jennifer J; Mack, Mick G
The present study examined the relationship between aggression and players' names on uniforms in collegiate women's ice hockey. Aggression was defined as mean penalty minutes per game. Information, i.e., win/loss record, penalties, and names on uniforms, about the 2002-2003 season women's ice hockey team was obtained via e-mail from 53 of 72 (74% return rate) sports information directors (Division I = 23, Division II = 2, Division III = 28). Analysis indicated that teams with personalized jerseys had significantly more penalty minutes per game than teams without personalized jerseys. However, as the majority of the teams with personalized jerseys were Division I teams and the majority of the teams without personalized jerseys were Division III teams, it is unclear whether results were due to personalized jersey or competition level of play.
Vucic, S.; Drost, R.W.; Ongkosuwito, E.M.; Wolvius, E.B.
BACKGROUND: Dentofacial injuries are a risk while playing field hockey. Wearing mouthguards is recommended. OBJECTIVE: To synthesise findings on the prevalence and characteristics of dentofacial injuries sustained by field hockey players. We also investigated the prevalence of regular mouthguard use
Pileggi, H; Stolper, C D; Boyle, J M; Stasko, J T
Sports analysts live in a world of dynamic games flattened into tables of numbers, divorced from the rinks, pitches, and courts where they were generated. Currently, these professional analysts use R, Stata, SAS, and other statistical software packages for uncovering insights from game data. Quantitative sports consultants seek a competitive advantage both for their clients and for themselves as analytics becomes increasingly valued by teams, clubs, and squads. In order for the information visualization community to support the members of this blossoming industry, it must recognize where and how visualization can enhance the existing analytical workflow. In this paper, we identify three primary stages of today's sports analyst's routine where visualization can be beneficially integrated: 1) exploring a dataspace; 2) sharing hypotheses with internal colleagues; and 3) communicating findings to stakeholders.Working closely with professional ice hockey analysts, we designed and built SnapShot, a system to integrate visualization into the hockey intelligence gathering process. SnapShot employs a variety of information visualization techniques to display shot data, yet given the importance of a specific hockey statistic, shot length, we introduce a technique, the radial heat map. Through a user study, we received encouraging feedback from several professional analysts, both independent consultants and professional team personnel.
Lars Meyer Sanches
Full Text Available The objective of this study is to investigate a phenomenon that occurs in Brazil, specifically the spike in demand at the end of the sales period, known as the hockey stick phenomenon. This analysis will encompass the causes as well as the impacts of this phenomenon, in a way that allows alternative policies to be evaluated. Data was collected from a Brazilian branch of a large multinational in the non-durable consumer goods industry and in semi-structured interviews conducted face-to-face with executives of 26 clients. The data was used to generate a continuous simulation model based on the methods of systems dynamics. The findings showed that the phenomenon negatively impacted the manufacturer’s financial performance in the long term and indicated required changes necessary to remediate the phenomenon. This is an empirical study on the hockey stick phenomenon, a problem that affects diverse companies in Brazil. The study showed that companies should not assume the hockey stick phenomenon to be an exogenous problem; it showed that there are policies able to improve financial performance; and it provided ideas regarding ways to carry out the change process.
... comments in Microsoft Word, Excel, WordPerfect, or Adobe PDF file formats only. FOR FURTHER INFORMATION... dead discards would be subtracted from the ACT to generate the TAL for the skate fisheries. After...
Full Text Available Klasifikasi pemain hockey dilakukan untuk mengklasifikasi pemain yang dapat lolos masuk tim utama dan gagal masuk tim utama. Klasifikasi dilakukan menggunakan data mining algoritma C4.5. Data yang digunakan untuk penelitian meliputi data multilevel pemain, data sprint, data tembakan push, data control bola, dan data game pemain. Proses data mining pada data training akan menghasilkan sebuah pohon keputusan atau rule. Metode evaluasi yang dilakukan dalam penelitian ini menggunakan confusion matrik dimana nilai akurasi untuk tiga kali pengujian mengalami kenaikan yaitu untuk prosentase data training dan data testing sebesar 70%:30% menghasilkan nilai akurasi sebesar 70%, prosentase data 80%:20% menghasilkan nilai akurasi sebesar 75%, dan untuk prosentase data 90%:10% menghasilkan nilai akurasi sebesar 80%. Ini membuktikan bahwa semakin besar data training maka semakin besar pula nilai akurasi yang didapat. Kata kunci : Hockey, klasifikasi, C4.5, data mining, confusion matrix
Ronkainen, Noora J; Ryba, Tatiana V
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. Emergent narratives surrounding existential themes of loss of meaning and loneliness in the face of injury were analysed in connection with players' search for authenticity and realignment with self-concept. Each player developed resistant narratives to the dominant ethos of professional sport in order to restore well-being and sense of self. The relational aspects of injury are highlighted in practical recommendations.
Amsler, M O; Smith, K E; McClintock, J B; Singh, H; Thatje, S; Vos, S C; Brothers, C J; Brown, A; Ellis, D; Anderson, J; Aronson, R B
A dense aggregation of skate egg cases was imaged during a photographic survey of the sea floor along the western Antarctic Peninsula in November 2013. Egg cases were noted in a narrow band between 394 and 443 m depth. Although some skate species in other oceans are known to utilize restricted areas to deposit eggs in great numbers, such nurseries have not been described in the Southern Ocean. © 2015 The Fisheries Society of the British Isles.
Goodman, Zack A; Thomas, Scott G; Wald, Robert C; Goodman, Jack M
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 <0.05). Both systolic and diastolic blood pressures decreased significantly throughout the duration of the 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 <0.05). In conclusion, recreational pick-up hockey in middle-aged 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
drs. T. Verstappen; drs. José Wichers-Bots
Een groot aantal hockeyclubs in Nederland biedt aangepaste hockeyfaciliteiten aan voor kinderen, jongeren en volwassenen met een verstandelijke beperking (G-hockey) of een lichamelijke beperking ( LG-hockey). Het doel van het aangepast hockey is mensen met een verstandelijke of lichamelijke
Huang, Wei; Hongjamrassilp, Watcharapong; Jung, Jae-Young; Hastings, Philip A; Lubarda, Vlado A; McKittrick, Joanna
Animal propulsion systems are believed to show high energy and mechanical efficiency in assisting movement compared to artificial designs. As an example, batoid fishes have very light cartilaginous skeletons that facilitate their elegant swimming via enlarged wing-like pectoral fins. The aim of this work is to illustrate the hierarchical structure of the pectoral fin of a representative batoid, the Longnose Skate (Raja rhina), and explain the mechanical implications of its structural design. At the macro level, the pectoral fins are comprised of radially oriented fin rays, formed by staggered mineralized skeletal elements stacked end-to-end. At the micro level, the midsection of each radial element is composed of three mineralized components, which consist of discrete segments (tesserae) that are mineralized cartilage and embedded in unmineralized cartilage. The radial elements are wrapped with aligned, unmineralized collagen fibers. This is the first report of the detailed structure of the ray elements, including the observation of a 3-chain mineralized tesserae. Structural analyses demonstrate that this configuration enhances stiffness in multiple directions. A two-dimensional numerical model based on the morphological analysis demonstrated that the tessera structure helps distributing shear, tensile and compressive stress more ideally, which can better support both lift and thrust forces when swimming without losing flexibility. Batoid fishes have very light cartilaginous skeletons that facilitate their elegant swimming by applying their enlarged wing-like pectoral fins. Previous studies have shown structural features and mechanical properties of the mineralized cartilage skeleton in various batoid fishes. However, the details of the pectoral fin structure at different length scales, as well as the relationship between the mechanical properties and structural design remains unknown. The present work illustrates the hierarchical structure of the pectoral fin of
Arkhipkin, A; Brickle, P; Laptikhovsky, V; Pompert, J; Winter, A
The eastern Patagonian Shelf and continental slope of the south-west Atlantic Ocean support a high biodiversity and abundance of skates. In this study, meso-scale differences in the assemblages, spatial and seasonal distributions of skates are revealed among six habitat zones of the eastern Patagonian Shelf characterized by distinctive oceanographic conditions. Most skates belonged to temperate fauna, and their abundance was much greater in habitats occupied by temperate waters (north-western outer shelf) or mixed waters (northern slope) than in habitats occupied by sub-Antarctic waters (SASW) (south-eastern outer shelf and southern slope). Sub-Antarctic skates were not abundant on the shelf even in habitats occupied by SASW, occurring mainly in deep areas of the lower continental slope. The majority of temperate skates migrated seasonally, shifting northward in winter and spreading southward with warming waters in summer. Most temperate species had two peaks in female maturity (mainly spring and autumn) and spawned in the same habitats where they fed. It is hypothesized that the high biodiversity and abundance of skates on the Patagonian Shelf and Slope are due to the practical absence of their natural competitors, flatfishes, which occupy similar eco-niches elsewhere. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.
Jiang, Chaozhe; Xu, Yibo; Wen, Chao; Chen, Dilin
Anti-runaway prevention of rolling stocks at a railway station is essential in railway safety management. The traditional track skates for anti-runaway prevention of rolling stocks have some disadvantages since they are operated and monitored completely manually. This paper describes an anti-runaway prevention system (ARPS) based on intelligent track skates equipped with sensors and real-time monitoring and management system. This system, which has been updated from the traditional track skates, comprises four parts: intelligent track skates, a signal reader, a database station, and a monitoring system. This system can monitor the real-time situation of track skates without changing their workflow for anti-runaway prevention, and thus realize the integration of anti-runaway prevention information management. This system was successfully tested and practiced at Sunjia station in Harbin Railway Bureau in 2014, and the results confirmed that the system showed 100% accuracy in reflecting the usage status of the track skates. The system could meet practical demands, as it is highly reliable and supports long-distance communication.
Full Text Available Anti-runaway prevention of rolling stocks at a railway station is essential in railway safety management. The traditional track skates for anti-runaway prevention of rolling stocks have some disadvantages since they are operated and monitored completely manually. This paper describes an anti-runaway prevention system (ARPS based on intelligent track skates equipped with sensors and real-time monitoring and management system. This system, which has been updated from the traditional track skates, comprises four parts: intelligent track skates, a signal reader, a database station, and a monitoring system. This system can monitor the real-time situation of track skates without changing their workflow for anti-runaway prevention, and thus realize the integration of anti-runaway prevention information management. This system was successfully tested and practiced at Sunjia station in Harbin Railway Bureau in 2014, and the results confirmed that the system showed 100% accuracy in reflecting the usage status of the track skates. The system could meet practical demands, as it is highly reliable and supports long-distance communication.
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
The study investigated the incidence and mechanism of ankle injuries amongst male adolescent hockey players in the Kwa-Zulu Natal. A descriptive survey was conducted amongst 53 male hockey players aged 16-18 years old, who by informed voluntary consent participated in the study. Data were collected by the use of ...
Vucic, S.; Drost, R.W.; van Wijk, A.J.; Wesselink, P.R.; Wolvius, E.B.
Background Orodental injuries in field hockey are a growing cause of concern that requires attention. Objective The objective of this cross-sectional study was to investigate the patterns of orodental injury, and the use of mouthguards in Dutch national field hockey. Materials and methods In the
Guillem Trabal Tañá
... 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...
Krotee, March L.; La Point, James D.
This paper presents the results of research conducted to investigate the relationship of various psychosocial variables on the positioning of college ice hockey players. The California Personality Inventory (CPI) was administered to the NCAA Championship ice hockey team at the University of Minnesota, and a separate subjective psychosocial rating…
Deits, Jeff; Yard, Ellen E; Collins, Christy L; Fields, Sarah K; Comstock, R Dawn
Although the number of US ice hockey participants doubled from 1990 to 2006, no nationally representative studies have examined US ice hockey injuries among participants of all ages during this period. To describe patients with ice hockey injuries presenting to a representative sample of US emergency departments (EDs) from 1990 through 2006. Prospective injury surveillance study. The US Consumer Product Safety Commission collects data from 100 nationally representative EDs via the National Electronic Injury Surveillance System (NEISS). Individuals injured while playing ice hockey and presenting to a NEISS-affiliated ED from 1990 through 2006. Incidence and patterns of ice hockey-related injuries. From 1990 through 2006, 8228 patients with ice hockey-related injuries presented to NEISS-affiliated EDs, representing an estimated 302 368 ice hockey-related injuries sustained nationally during this time. Injuries occurred predominantly among males (93.5%). More than half of the injured were aged 9 to 14 years (28.9%) or 15 to 18 years (30.1%), and injury incidence in these age groups increased over the study period (P = .009 and P Ice hockey injury patterns vary by age and sex. Our findings indicate that many trips to the ED might be prevented by using protective equipment appropriately.
Examined the relationship between gender, physicality, and embodiment among Canadian adolescent girls who played ice hockey. Interview data indicated that the girls emphasized the importance of being aggressive (fearless in use of the body). Players understood that contrasts between men's hockey (more physical and aggressive) and women's hockey…
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
Ackery, Alun D; Tator, Charles H; Snider, Carolyn
To determine the perceptions and roles of referees about violence and injury in hockey games. Questionnaire. Web-based survey. We contacted referees across Canada from various leagues and all levels of play, with the majority of respondents from Ontario (92%). We gathered demographic information anonymously and posed questions on aggression and experience in hockey games. The majority of referees (n = 632) indicated that violence is a serious concern to both players and referees at all levels of hockey. More than 90% of referees responded that they were the recipients of aggression and anger (92.1%, 95% confidence interval, 90.0-94.2), 55% had been involved in hockey games where aggressive behavior resulted in the referee losing control of the game, and 71% said that this increased aggression leads to injury. Referees' opinions are that the coach is the most responsible for managing on-ice safety (63%). To improve hockey safety, referees suggest education and more rigorous enforcement of discipline for all participants. Referees are important for hockey safety and need to be appropriately supported. Referees believe that increased aggression can lead to injury and that rules need to be enforced more diligently. Referees recommend that increased education about safety is needed to guide parents, coaches, and players to make hockey safer.
Wolfinger, Christopher R; Davenport, Todd E
The increasing number of athletes playing hockey compels rehabilitation professionals working in orthopedic and sports settings to understand the unique functional demands of ice hockey and the patterns of injuries they may promote. The purpose of this clinical perspective is to: (1) discuss the functional implications of different positions and age levels on injury prevalence within the sport; (2) summarize the seven most common injuries sustained by ice hockey athletes; and (3) present a conceptual model for the clinical management and prevention of these injuries by rehabilitation professionals. A narrative review and synthesis was conducted of currently available literature on prevalence, etiology, rehabilitative intervention, prognosis, and prevention of ice hockey injuries. Research evidence is available to support the prevalence of injuries sustained while participating in ice hockey, as well as the most effective clinical treatment protocols to treat them. Most of the existing protocols are based on clinical and sports experience with incorporation of scientific data. This clinical commentary reviews the current concepts of ice hockey injury care and prevention, based on scientific information regarding the incidence, mechanism, rehabilitation protocols, prognosis, and prevention of injuries. Science-based, patient-centered reasoning is integral to provide the highest quality of rehabilitative and preventative care for ice hockey athletes by physical therapists. 5.
Kuzuhara, Kenji; Shimamoto, Hideki; Mase, Yasuyoshi
Context: As the Asian Ice Hockey League gradually expands and becomes more competitive, ice hockey-related injuries may increase. However, no reports have been published on ice hockey injuries in Japan, including the method of injury and the daily supervision of the players during the regular season. Objective: To prospectively study the incidence, types, and mechanisms of ice hockey injuries in an elite Japanese ice hockey team. Design: Prospective observational cohort study design. Setting: An elite ice hockey team, Tokyo, Japan. Patients or Other Participants: Ninety-four players during the 2002–2005 seasons. Main Outcome Measure(s): Data were collected for 3 consecutive seasons using an injury reporting form. Results: The overall game injury rate was 74.3 per 1000 player-game hours and 11.7 per 1000 player-game hours for injuries resulting in any time loss. The overall practice injury rates were 11.2 per 1000 player-practice hours and 1.1 per 1000 player-practice hours for injuries resulting in any time loss. Forwards had the highest rate of injury, followed by defensemen and then goalkeepers. Contusions were the most common injury, followed by strains, lacerations, and sprains. Conclusions: Most injuries among Japanese ice hockey players occurred during games. Game or play intensity may influence the injury rate during games. PMID:19295967
Popkin, Charles A; Schulz, Brian M; Park, Caroline N; Bottiglieri, Thomas S; Lynch, T Sean
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.
Broekstra, Dieuwke C; van den Heuvel, Edwin R; Lanting, Rosanne; Harder, Tom; Smits, Inge; Werker, Paul M N
Dupuytren disease is a fibroproliferative hand condition. The role of exposure to vibration as a risk factor has been studied with contradictory results. Since field hockey is expected to be a strong source of hand-arm vibration, we hypothesised that long-term exposure to field hockey is associated with Dupuytren disease. In this cross-sectional cohort study, the hands of 169 male field hockey players (IQR: 65-71 years) and 156 male controls (IQR: 59-71 years) were examined for signs of Dupuytren disease. Details about their age, lifestyle factors, medical history, employment history and leisure activities were gathered. Prior to the analyses, the groups were balanced in risk factors using propensity score matching. The association between field hockey and Dupuytren disease was determined using a subject-specific generalised linear mixed model with a binomial distribution and logit link function (matched pairs analysis). Dupuytren disease was observed in 51.7% of the field hockey players, and in 13.8% of the controls. After propensity score matching, field hockey playing as dichotomous variable, was associated with Dupuytren disease (OR=9.42, 95% CI 3.01 to 29.53). A linear dose-response effect of field hockey (hours/week x years) within the field hockey players could not be demonstrated (OR=1.03, 95% CI 0.68 to 1.56). We found that field hockey playing has a strong association with the presence of Dupuytren disease. Clinicians in sports medicine should be alert to this less common diagnosis in this sport. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
Wilcox C, R J; Osgood, Chad T; White H, S F; Vince, Rebecca V
Ice hockey athletes frequently injure the hip complex via a noncontact mechanism. The authors investigated patterns of strength and range of motion (ROM) to establish major differences compared with soccer athletes. Soccer athletes were compared with ice hockey athletes due to similarities between the 2 sports with regard to the intermittent nature and high number of lower-limb injuries. To compare the differences in ROM and strength of the hip for both the dominant (Dom) and nondominant (Ndom) limbs in ice hockey and soccer athletes. Case-control study. Bilateral ROM in hip flexion in sitting (FS) and lying (FL), extension, abduction, adduction, and internal rotation (IR) and external rotation (ER) were measured using a goniometer and assessed for strength using a handheld dynamometer on both the Dom and Ndom limbs. 24 male, active, uninjured NCAA Division III ice hockey (16) and soccer (8) athletes. ROM and strength for hip FS, FL, extension, abduction, adduction, IR, and ER. A mixed-model ANOVA was used to investigate interactions and main effects. Ice hockey athletes exhibited greater hip-adduction ROM than soccer athletes in the Dom leg (both P = .002) and when both limbs were combined (P = .010). Ice hockey athletes had less ROM in ER (P = .042) than soccer athletes. Ice hockey athletes displayed less strength in adduction in their Ndom leg than in their Dom leg (P = .02), along with less adduction than soccer players in their Ndom leg (P = .40). Ice hockey athletes displayed less strength in hip adduction (P = .030), FS (P = .023) and FL (P = .030) than soccer athletes. The findings suggest that ice hockey athletes may present an at-risk profile for noncontact hip injuries in comparison with soccer athletes with regard to strength and ROM of the hip.
MacDonald, Erin E; Volkoff, Hélène
A 815 base pairs (bp) cDNA encoding for preproorexin (preproOX) was cloned in winter skate, a cartilaginous fish. Winter skate preproOX is 159 amino acids (aa) long and contains a 34 aa orexin A and 28 aa orexin B. The amino acid sequence of winter skate preproOX is more similar to tetrapod preproOXs (36-40% identity) than teleost preproOXs (23-33% identity). Whereas orexin B appears relatively well conserved among vertebrates, orexin A displays more variability, in particular due to an "insertion sequence" that is present in teleost fish, but not in skate and tetrapods. RT-PCR studies show that preproOX mRNA has a widespread distribution within the brain and is present in several peripheral tissues, including gastrointestinal tract, heart and testes. Fasting induced increases in preproOX expression in the hypothalamus, suggesting that orexin might play a role in the regulation of food intake in winter skate. Copyright © 2010 Elsevier Inc. All rights reserved.
Randhawa, Haseeb S
Host-parasite interactions generally involve communities of parasites. Within these communities, species will co-exist and/or interact with one another in a manner either benefiting the species involved or to the detriment of one or more of the species. At the level of helminth infracommunities, evidence for intra- and inter-specific competition includes numerical responses, i.e. those regulating helminth intensity of infection, and functional responses, i.e. where the presence of competitors modifies the realised niche of infrapopulations. The objectives of this study are to assess the numerical and functional responses of helminths in infracommunities from 3 rajid skates using general linear models. Despite a lack of numerical responses, functional responses to intra- and inter-specific interactions were observed. A positive correlation between the number of individuals in an infrapopulation and its niche breadth (functional response) was observed for the tapeworms Pseudanthobothrium spp. and Echeneibothrium spp., in all their respective hosts, and for the nematode Pseudanisakis sp. in the little skate. Evidence for inter-specific competition includes niche shifts in Pseudanthobothrium purtoni (ex little skate) and Pseudanisakis sp. (ex thorny skate) in the presence of Pseudanisakis sp. and the tapeworm Grillotia sp., respectively. These results are consistent with other studies in providing evidence for competition between helminths of skates.
Kroshus, Emily; Daneshvar, Daniel H; Baugh, Christine M; Nowinski, Christopher J; Cantu, Robert C
Despite concussion education being increasingly mandated by states and sports leagues, there has been limited evaluation of what education is in fact effective. The National Collegiate Athletic Association (NCAA) currently mandates that institutions provide concussion education, without specifying content or delivery. The present study evaluated the effectiveness of this general mandate, as enacted for male collegiate ice hockey teams within one conference of competition. In a prospective cohort design, 146 players from 6 male collegiate ice hockey teams in one Division 1 conference completed written surveys before and after receiving their institution-determined concussion education. Knowledge, attitudes, perceived norms and behavioural intention were assessed using validated measures. Education content and delivery was assessed by open-ended responses and consultation with team athletic trainers. All teams received concussion education material; however, content and delivery varied. Rates of material recall differed by delivery format. Considering all teams together, there were no significant improvements in knowledge and only a very small decrease in intention to continue playing while experiencing symptoms of a concussion. Pre-education and post-education, there were significant between-team differences in attitudes towards concussion reporting and behavioural intention. The NCAA's general education mandate was divergently enacted; it did not significantly change the constructs of interest nor did it mitigate the pre-education team differences in these constructs. Existing educational materials should be evaluated, theory and evidence-driven materials developed, and mandates extended to, at a minimum, recommend materials found to be effective in changing concussion-reporting behaviour.
Clark, J Michio; Hoshizaki, T Blaine; Gilchrist, Michael D
The purpose of this study was to assess the protective capacity of an ice hockey goaltender helmet for three concussive impact events. A helmeted and unhelmeted headform was used to test three common impact events in ice hockey (fall, puck impacts and shoulder collisions). Peak linear acceleration, rotational acceleration and rotational velocity as well as maximum principal strain and von Mises stress were measured for each impact condition. The results demonstrated the tested ice hockey goaltender helmet was well designed to manage fall and puck impacts but does not consistently protect against shoulder collisions and an opportunity may exist to improve helmet designs to better protect goaltenders from shoulder collisions.
Philippon, Marc J; Ho, Charles P; Briggs, Karen K; Stull, Justin; LaPrade, Robert F
It has been reported that relative to other sports participants, ice hockey players suffer from cam-type femoroacetabular impingement (FAI) in higher numbers. α angles have been reported to increase with the likelihood of symptomatic FAI. It is unclear how prevalent increased α angles, commonly associated with cam FAI, are in asymptomatic young ice hockey players. There would be a higher prevalence of α angles associated with cam FAI in youth ice hockey players than in a non-hockey-playing (skier) youth control group. Cohort study; Level of evidence, 3. A total of 61 asymptomatic youth ice hockey players (aged 10-18 years) and 27 youth skiers (controls) (aged 10-18 years) underwent a clinical hip examination consisting of the flexion/abduction/external rotation (FABER) distance test, impingement testing, and measurement of hip internal rotation. The hip α angle was measured by magnetic resonance imaging, and labral tears and articular cartilage lesions were documented. Hockey players were grouped according to their USA Hockey classification as peewees (ages 10-12 years), bantams (ages 13-15 years), and midgets (ages 16-19 years). Overall, ice hockey players had significantly higher α angles than did the control group, and hockey players had a significant correlation between increased age and increased α angles, while the control group did not. In the ice hockey group, 75% had an α angle of ≥55°, while in the skier group, 42% had an α angle of ≥55° (P Hockey players were 4.5 times more likely to have an α angle commonly associated with cam impingement than skiers. Midget players had the highest risk of increased α angles. Even at young ages, ice hockey players have a greater prevalence of α angles associated with cam FAI than do skier-matched controls. Properties inherent to ice hockey likely enhance the development of a bony overgrowth on the femoral neck, leading to cam FAI.
Forman, J S; Dunn, M R
The diet of smooth skate Dipturus innominatus was determined from examination of stomach contents of 321 specimens of 29·3-152·0 cm pelvic length, sampled from research and commercial trawlers at depths of 231-789 m on Chatham Rise, New Zealand. The diet was dominated by the benthic decapods Metanephrops challengeri and Munida gracilis, the natant decapod Campylonotus rathbunae and fishes from 17 families, of which hoki Macruronus novaezelandiae, sea perch Helicolenus barathri, various Macrouridae and a variety of discarded fishes were the most important. Multivariate analyses indicated the best predictors of diet variability were D. innominatus length and a spatial model. The diet of small D. innominatus was predominantly small crustaceans, with larger crustaceans, fishes and then scavenged discarded fishes increasing in importance as D. innominatus got larger. Scavenged discards were obvious as fish heads or tails only, or skeletal remains after filleting, often from pelagic species. Demersal fish prey were most frequent on the south and west Chatham Rise, in areas where commercial fishing was most active. Dipturus innominatus are highly vulnerable to overfishing, but discarding practices by commercial fishing vessels may provide a positive feedback to populations through improved scavenging opportunities. © 2012 NIWA. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.
Cusimano, Michael D; Nastis, Sofia; Zuccaro, Laura
..., 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...
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
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.
Vitiello Andrew L
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
Julian, Chris; Hoskins, Wayne; Vitiello, Andrew L
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. 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. 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. This study documented the injury profile of ice hockey at an international level of competition. It documented the conditions presenting to a chiropractor for
Saraví, Jorge Ricardo
El objetivo general que nos hemos planteado fue analizar la práctica del skate que llevan adelante los y las jóvenes en la ciudad. Por otro lado, nuestros objetivos específicos fueron: 1) relevar y describir acciones, características, particularidades, lugares, que asumen las diferentes prácticas del skate en la ciudad; 2) conocer las representaciones que acerca de esa práctica tienen los propios jóvenes y la sociedad; 3) profundizar en las implicancias sociales que tiene una práctica corpora...
Byrkjedal, I; Christiansen, J S; Karamushko, O V; Langhelle, G; Lynghammar, A
During scientific surveys on the continental slopes north-west of Spitsbergen and off north-east Greenland (c. 600 and 1000 m depths), two female Arctic skates Amblyraja hyperborea were caught while swallowing extraordinary large individuals of glacial eelpout Lycodes frigidus. The total length (LT) of the prey constituted 50 and 80% of the LT of the skates, which reveal that A. hyperborea are capable predators of fishes of surprisingly large relative size. © 2014 The Fisheries Society of the British Isles.
Full Text Available On the basis factors analysis of development methodical and organizational bases sporting preparation conformities to conformity and prospects of development of ice-hockey are shown. The system of competitions in hockey in the different regions of the world has distinctions on meaningfulness of sporting result. It influences on the structure of training process and function of his direction - system of planning, design, control, selection. Presented foundation for the prospect perfection sport game in Ukraine.
Reed, Nick; Taha, Tim; Greenwald, Richard; Keightley, Michelle
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.
Rousseau, Philippe; Hoshizaki, Thomas B
Reconstruction of real-life events can be used to investigate the relationship between the mechanical parameters of the impact and concussion risk. Striking mass has typically been approximated as being the mass of the body part coming into contact with the head without accounting for the force applied by the striking athlete. Thus, the purpose of this study was to measure the effective impact mass of three common striking techniques in ice hockey. Fifteen participants were instructed to strike a suspended 50th percentile Hybrid III headform at least three times with their elbow or shoulder. Effective impact mass was calculated by measuring the change in velocity of the player and the headform. Mean effective impact mass for the extended elbow, tucked-in elbow, and shoulder check conditions were 4.8, 3.0, and 12.9 kg, respectively. Peak linear accelerations were lower than the values associated with concussion in American football which could be a reflection of the methodology used in this study as well as inherent differences between both sports.
Degen, Ryan M; Fink, Matthew E; Callahan, Lisa; Fibel, Kenton H; Ramsay, Jim; Kelly, Bryan T
Head injuries are relatively common in ice hockey, with the majority represented by concussions, a form of mild traumatic brain injury. More severe head injuries are rare since the implementation of mandatory helmet use in the 1960s. We present a case of a 27 year-old male who sustained a traumatic intraparenchymal hemorrhage with an associated subdural hematoma resulting after being struck by a puck shot at high velocity. The patient presented with expressive aphasia, with no other apparent neurologic deficits. Acutely, he was successfully treated with observation and serial neuroimaging studies ensuring an absence of hematoma expansion. After a stable clinical picture following 24 hours of observation, the patient was discharged and managed with outpatient speech therapy with full resolution of symptoms and return to play 3 months later. We will outline the patient presentation and pertinent points in the management of acute head injuries in athletes.
Smith, Aynsley M; Stuart, Michael J; Dodick, David W; Roberts, William O; Alford, Patrick W; Ashare, Alan B; Aubrey, Mark; Benson, Brian W; Burke, Chip J; Dick, Randall; Eickhoff, Chad; Emery, Carolyn A; Flashman, Laura A; Gaz, Daniel V; Giza, Chris C; Greenwald, Richard M; Herring, Stanley A; Hoshizaki, T Blaine; Hudziak, James J; Huston, John; Krause, David; LaVoi, Nicole; Leaf, Matt; Leddy, John J; MacPherson, Alison; McKee, Ann C; Mihalik, Jason P; Moessner, Anne M; Montelpare, William J; Putukian, Margot; Schneider, Kathryn J; Szalkowski, Ron; Tabrum, Mark; Whitehead, James R; Wiese-Bjornstal, Diane M
This study aimed to present currently known basic science and on-ice influences of sport-related concussion (SRC) in hockey, building upon the Ice Hockey Summit I action plan (2011) to reduce SRC. The prior summit proceedings included an action plan intended to reduce SRC. As such, the proceedings from Summit I served as a point of departure for the science and discussion held during Summit II (Mayo Clinic, Rochester, MN, October 2013). Summit II focused on (1) Basic Science of Concussions in Ice Hockey: Taking Science Forward, (2) Acute and Chronic Concussion Care: Making a Difference, (3) Preventing Concussions via Behavior, Rules, Education, and Measuring Effectiveness, (4) Updates in Equipment: Their Relationship to Industry Standards, and (5) Policies and Plans at State, National, and Federal Levels To Reduce SRC. Action strategies derived from the presentations and discussion described in these sectors were voted on subsequently for purposes of prioritization. The following proceedings include the knowledge and research shared by invited faculty, many of whom are health care providers and clinical investigators. The Summit II evidence-based action plan emphasizes the rapidly evolving scientific content of hockey SRC. It includes the most highly prioritized strategies voted on for implementation to decrease concussion. The highest-priority action items identified from the Summit include the following: (1) eliminate head hits from all levels of ice hockey, (2) change body checking policies, and (3) eliminate fighting in all amateur and professional hockey.
Williamson, I J S; Goodman, D
Background Concussions are potentially serious injuries. The few investigations of prevalence or incidence in youth ice hockey have typically relied on prospective reports from physicians or trainers and did not survey players, despite the knowledge that many athletes do not report probable concussions. Objective This study sought to compare concussion rates in youth ice hockey that were estimated from a variety of reporting strategies. Methods Rates were calculated from British Columbia Amateur Hockey Association (BCAHA) official injury reports, from direct game observation by minor hockey volunteers (such as coaches and managers), as well as from retrospective surveys of both elite and non‐elite youth players. All research was conducted within the BCAHA. Results Estimates from official injury reports for male players were between 0.25 and 0.61 concussions per 1000 player game hours (PGH). Concussion estimates from volunteer reports were between 4.44 and 7.94 per 1000 PGH. Player survey estimates were between 6.65 and 8.32 per 1000 PGH, and 9.72 and 24.30 per 1000 PGH for elite and non‐elite male youth hockey, respectively. Conclusion It was found that concussions are considerably under‐reported to the BCAHA by youth hockey players and team personnel. PMID:16431999
Lutton, B V; Callard, I P
In elasmobranchs, the epigonal organ, a unique leukopoietic immune tissue, is associated with the gonads. As the ovaries increase in size during reproductive activity, the overall mass of the epigonal organ does not change. However, immunohistochemistry (proliferating cell nuclear antigen Ab) demonstrated more proliferative activity and extravasation of epigonal leukocytes from blood vessels in reproductively active (RA) skates (Leucoraja erinacea) than in non-reproductively active (NRA) skates. In addition, [(3)H]thymidine incorporation was greater in epigonal leukocytes from RA skates than in leukocytes from NRA skates. Plasma from RA skates, but not from NRA skates, increased proliferation of epigonal leukocytes in vitro, an effect that was not seen using steroid-free plasma. In contrast to the stimulatory effect of plasma on leukocyte proliferation, addition of steroids (estrogen, progesterone, testosterone, and dexamethasone) in vitro decreased [(3)H]thymidine incorporation. While the inhibitory response to steroids was seasonally variable, (3)[H]thymidine incorporation was always highest in RA animals, in which plasma steroid levels were also consistently highest. These studies suggest functional interactions between reproductive and immune tissues in the skate, and that cellular turnover in epigonal tissue may be influenced by gonadal activity.
Ong, Géraldine; Connelly, Kim Alexander; Goodman, Jack; Leong-Poi, Howard; Evangelista, Vene; Levitt, Kevin; Gledhill, Norman; Jamnik, Veronica; Gledhill, Scott; Yan, Andrew Tze-Kay; Chan, Kwan-Leung; Chow, Chi-Ming
The "athletic heart" is characterized by hypertrophy and dilation of the heart, in addition to functional and electrical remodeling. The aim of this study was to provide reference 2-dimensional (2DE) and 3-dimensional (3DE) echocardiographic measurements in a large database on draft-eligible elite ice hockey players and to determine the frequency of occult cardiac anomalies in this cohort of athletes. In this prospective cohort study, we performed a comprehensive cardiac assessment of the 100 top draft picks selected by the National Hockey League. Complete 2DE and 3DE examinations were performed to obtain comprehensive measurements of cardiac structure and function at rest, which were compared with nonathlete controls. A total of 592 athletes were evaluated (mean age 18 ± 0.5 years) from 2009 to 2014 at the National Hockey League combine. 2DE and 3DE ventricular, atrial dimensions, and left ventricular mass were significantly greater in the athletes compared with controls. Abnormalities were identified in 15 hockey players (2.5%) consisting of a bicuspid aortic valve in 10 (1.7%), patent ductus arteriosus in 1 (0.2%), low normal left ventricular systolic function in 2 (0.3%), an idiopathic pericardial effusion in 1 (0.2%), and posterior mitral valve prolapse in 1 (0.2%). In conclusion, intense ice hockey training is associated with typical myocardial adaptations and the frequency of cardiac anomalies found in this cohort of young elite hockey players is low and does not differ significantly from the reported incidences in the general population. Copyright © 2017 Elsevier Inc. All rights reserved.
Mulas, A; Bellodi, A; Cannas, R; Cau, Al; Cuccu, D; Marongiu, M F; Porcu, C; Follesa, M C
A total of 255 longnosed skate Dipturus oxyrinchus caught in Sardinian waters (central-western Mediterranean Sea), was analysed with respect to fish total length (LT ), season and depth, in order to provide information on diet and feeding behaviour. Specimens ranging from 93 to 1153 mm LT , were collected at depths between 121 and 671 m, during experimental trawl surveys carried out from 2005 to 2010. The diet comprised crustaceans [prey specific index of relative importance (%IPSRI ) = 72·69], teleosts (%IPSRI = 10·28) and molluscs (%IPSRI = 10·94). Levins' index (Bi ) showed a narrow niche breadth (Bi = 0·35). The mean ± s.e. trophic level (TL ) was 3·63 ± 0·50. The analysis showed major ontogenetic changes in the feeding behaviour. Early life stages were characterized by a benthic diet, which changed to benthopelagic during growth. Mysids, particularly Lophogaster typicus (%IPSRI = 34·51), were the main prey items of immature individuals, replaced by euphausiids, mainly Meganyctiphanes norvegica (%IPSRI = 13·19), in maturing fish. Crustaceans became less important in mature specimens, being replaced by molluscs (%IPSRI = 28·99) and teleosts (%IPSRI = 24·56). A concomitant increase of the TL was recorded (mean ± s.e. = 3·41 ± 0·44, 3·75 ± 0·54 and 4·28 ± 0·61 for immature, maturing and mature individuals). These feeding patterns ensured low levels of intraspecific competition. This study provides new information about the role that the D. oxyrinchus plays in the marine food chain and data now essential to formulate new and effective management plans for this species. © 2014 The Fisheries Society of the British Isles.
Irigoitia, Manuel Marcial; Braicovich, Paola Elizabeth; Lanfranchi, Ana Laura; Farber, Marisa Diana; Timi, Juan Tomás
In order to evaluate the infestation by anisakids present in elasmobranchs and their distribution in the Argentine Sea, this study was carried at a regional scale with the following aims: 1) to identify those anisakid species present in skates under exploitation; 2) to characterize quantitatively these infestations and 3) to determine those factors driving the variability in parasite burdens across skate species. A total of 351 skates, belonging to 3 species (218 Sympterygia bonapartii, 86 Zearaja chilensis and 47 Atlantoraja castelnaui) and from different localities of the Argentine Sea were examined for anisakids. Parasites were found in the stomach wall at high prevalence in some samples. Based on morphology and mtDNA cox2 sequences analyses (from 24 larval worms), specimens were identified as Anisakis berlandi, A. pegreffii and Pseudoterranova cattani; the last two known as potentially pathogenic for humans. Differential distribution patterns were observed across parasite and hosts species. In general, fish caught in southern and deeper waters exhibited higher loads of Anisakis spp., whereas infestation levels by P. cattani increase in larger skates. Taking into account that the mere presence of worms or their antigens in fish meat can provoke allergic responses, information on distribution of parasites and their variability is essential for the implementation of food safety practices. Copyright © 2017 Elsevier B.V. All rights reserved.
Collections of chondrichthyan egg-cases cast ashore at two sites along the South African coastline were identified and examined for cause of mortality. A total of 574 egg-cases collected from False Bay could be attributed to five species of scyliorhinid shark. two skates and the elephantfish or chimaera, while the 538 ...
Collections of chondrichthyan egg-cases cast ashore at two sites along the South African coastline were identi- fied and examined for cause of mortality. A total of 574 egg-cases collected from False Bay could be attributed to five species of scyliorhinid shark. two skates and the elephantfish or chimaera, while the 538 ...
Bolger, Conor M; Kocbach, Jan; Hegge, Ann Magdalen; Sandbakk, Øyvind
To compare the speed and heart-rate profiles during international skating and classical competitions in male and female world-class cross-country skiers. Four male and 5 female skiers performed individual time trials of 15 km (men) and 10 km (women) in the skating and classical techniques on 2 consecutive days. Races were performed on the same 5-km course. The course was mapped with GPS and a barometer to provide a valid course and elevation profile. Time, speed, and heart rate were determined for uphill, flat, and downhill terrains throughout the entire competition by wearing a GPS and a heart-rate monitor. Times in uphill, flat, and downhill terrain were ~55%, 15-20%, and 25-30%, respectively, of the total race time for both techniques and genders. The average speed differences between skating and classical skiing were 9% and 11% for men and women, respectively, and these values were 12% and 15% for uphill, 8% and 13% for flat (all P profiles were relatively independent of technique and gender. The greatest performance differences between the skating and classical techniques and between the 2 genders were found on uphill terrain. Therefore, these speed differences could not be explained by variations in exercise intensity.
Chevolot, Malia; Wolfs, Peter H. J.; Palsson, Jonbjorn; Rijnsdorp, Adriaan D.; Stam, Wytze T.; Olsen, Jeanine L.; Palson, J.
Population genetic structure of the thorny skate (Amblyraja radiata) was surveyed in > 300 individuals sampled from Newfoundland, Iceland, Norway, the Kattegat and the central North Sea. A 290-bp fragment of the mt cytochrome-b gene was first screened by SSCP. Sequences of SSCP haplotypes revealed
Wang, Qinghua; Arighi, Cecilia N; King, Benjamin L; Polson, Shawn W; Vincent, James; Chen, Chuming; Huang, Hongzhan; Kingham, Brewster F; Page, Shallee T; Rendino, Marc Farnum; Thomas, William Kelley; Udwary, Daniel W; Wu, Cathy H
Recent advances in high-throughput DNA sequencing technologies have equipped biologists with a powerful new set of tools for advancing research goals. The resulting flood of sequence data has made it critically important to train the next generation of scientists to handle the inherent bioinformatic challenges. The North East Bioinformatics Collaborative (NEBC) is undertaking the genome sequencing and annotation of the little skate (Leucoraja erinacea) to promote advancement of bioinformatics infrastructure in our region, with an emphasis on practical education to create a critical mass of informatically savvy life scientists. In support of the Little Skate Genome Project, the NEBC members have developed several annotation workshops and jamborees to provide training in genome sequencing, annotation and analysis. Acting as a nexus for both curation activities and dissemination of project data, a project web portal, SkateBase (http://skatebase.org) has been developed. As a case study to illustrate effective coupling of community annotation with workforce development, we report the results of the Mitochondrial Genome Annotation Jamborees organized to annotate the first completely assembled element of the Little Skate Genome Project, as a culminating experience for participants from our three prior annotation workshops. We are applying the physical/virtual infrastructure and lessons learned from these activities to enhance and streamline the genome annotation workflow, as we look toward our continuing efforts for larger-scale functional and structural community annotation of the L. erinacea genome.
Chevolot, M.; Wolfs, P.H.J.; Palsson, J.; Rijnsdorp, A.D.; Stam, W.T.; Olsen, J.L.
Population genetic structure of the thorny skate (Amblyraja radiata) was surveyed in >300 individuals sampled from Newfoundland, Iceland, Norway, the Kattegat and the central North Sea. A 290-bp fragment of the mt cytochrome-b gene was first screened by SSCP. Sequences of SSCP haplotypes revealed
Barnett, Lewis A K; Winton, Megan V; Ainsley, Shaara M; Cailliet, Gregor M; Ebert, David A
Age-structured demographic models were constructed based on empirical estimates of longevity and maturity for five deepwater Bering Sea skates to investigate how observed differences in life history parameters affect population growth rates. Monte Carlo simulations were used to incorporate parameter uncertainty. Estimated population growth rates ranged from 1.045 to 1.129 yr(-1) and were lower than those reported for other Alaskan skates and most chondrichthyans. Population growth rates of these and other high-latitude skates increased with relative reproductive lifespan, but displayed no significant relationship with body size or depth distribution, suggesting that assemblage shifts may be difficult to predict for data-poor taxa. Elasticity analyses indicated that juvenile and adult survival had greater per-unit effects on population growth rates than did egg-case survival or fecundity. Population growth rate was affected more by uncertainty in age at maturity than maximum age. The results of this study indicate that if skates are deemed to be a management concern, gear modifications or depth-specific effort controls may be effective.
Wang, Qinghua; Arighi, Cecilia N.; King, Benjamin L.; Polson, Shawn W.; Vincent, James; Chen, Chuming; Huang, Hongzhan; Kingham, Brewster F.; Page, Shallee T.; Farnum Rendino, Marc; Thomas, William Kelley; Udwary, Daniel W.; Wu, Cathy H.
Recent advances in high-throughput DNA sequencing technologies have equipped biologists with a powerful new set of tools for advancing research goals. The resulting flood of sequence data has made it critically important to train the next generation of scientists to handle the inherent bioinformatic challenges. The North East Bioinformatics Collaborative (NEBC) is undertaking the genome sequencing and annotation of the little skate (Leucoraja erinacea) to promote advancement of bioinformatics infrastructure in our region, with an emphasis on practical education to create a critical mass of informatically savvy life scientists. In support of the Little Skate Genome Project, the NEBC members have developed several annotation workshops and jamborees to provide training in genome sequencing, annotation and analysis. Acting as a nexus for both curation activities and dissemination of project data, a project web portal, SkateBase (http://skatebase.org) has been developed. As a case study to illustrate effective coupling of community annotation with workforce development, we report the results of the Mitochondrial Genome Annotation Jamborees organized to annotate the first completely assembled element of the Little Skate Genome Project, as a culminating experience for participants from our three prior annotation workshops. We are applying the physical/virtual infrastructure and lessons learned from these activities to enhance and streamline the genome annotation workflow, as we look toward our continuing efforts for larger-scale functional and structural community annotation of the L. erinacea genome. PMID:22434832
... anonymous). Attachments to electronic comments will be accepted in Microsoft Word or Excel, WordPerfect, or... allowable landings (TALs) for the skate wing and bait fisheries (TAL = ACT - dead discards and state... the assumed discard mortality rate of 50 percent is too high, and that the dead discard portion of the...
Stoter, Inge K; MacIntosh, Brian R; Fletcher, Jared R; Pootz, Spencer; Zijdewind, Inge; Hettinga, Florentina J
PURPOSE: To evaluate pacing behavior and peripheral and central contributions to muscle fatigue in 1500m speed skating and cycling time-trials, when a faster or slower start is instructed. METHODS: Nine speed skaters and nine cyclists, all competing at regional or national level, performed two 1500m
Hettinga, F. J.; De Koning, J. J.; Schmidt, L. J. I.; Wind, N. A. C.; MacIntosh, B. R.; Foster, C.
Purpose Athletes are trained to choose the pace which is perceived to be correct during a specific effort, such as the 1500-m speed skating competition. The purpose of the present study was to "override" self-paced (SP) performance by instructing athletes to execute a theoretically optimal pacing
Hettinga, F.J.; de Koning, J.J.; Schmidt, L.J.I.; Wind, N.A.C.; McIntosh, B.; Foster, C.
Purpose: Athletes are trained to choose the pace which is perceived to be correct during a specific effort, such as the 1500-m speed skating competition. The purpose of the present study was to "override" self-paced (SP) performance by instructing athletes to execute a theoretically optimal pacing
Pantoja Patrícia Dias
Full Text Available This study aimed to describe the neuromuscular activity of elite athletes who performed various roller figure skating jumps, to determine whether the muscle activation is greater during jumps with more rotations and in which phase the muscles are more active. This study also aimed to analyze if there is any difference in the muscle activity pattern between female and male skaters. Four elite skaters were evaluated, and each participated in two experimental sessions. During the first session, anthropometric data were collected, and the consent forms were signed. For the second session, neuromuscular data were collected during jumps, which were performed with skates at a rink. The following four roller figure skating jumps were evaluated: single Axel, double Axel, double Mapes and triple Mapes. The neuromuscular activity of the following seven muscles was obtained with an electromyograph which was fixed to the waist of each skater with a strap: biceps femoris, lateral gastrocnemius, tibialis anterior, rectus femoris, vastus lateralis, vastus medialis and gluteus maximus. The signal was transmitted wirelessly to a laptop. During the roller figure skating jumps, the lateral gastrocnemius, rectus femoris, vastus lateralis, biceps femoris and gluteus maximus, showed more activation during the jumps with more rotations, and the activation mainly occurred during the propulsion and flight phases. Female skaters demonstrated higher muscle activities in tibialis anterior, vastus lateralis, vastus medialis and gluteus maximus during the landing phase of the triple Mapes, when compared to their male counterparts. The results obtained in this study should be considered when planning training programs with specific exercises that closely resemble the roller figure skating jumps. This may be important for the success of elite skaters in competitions.
The large receptive fields of retinal horizontal cells result primarily from extensive intercellular coupling via gap (electrical) junctions; thus, the extent of the receptive field provides an index of the degree to which the cells are electrically coupled. For rod-driven horizontal cells in the dark-adapted skate retina, a space constant of 1.18 +/- 0.15 mm (SD) was obtained from measurements with a moving slit stimulus, and a comparable value (1.43 +/- 0.55 mm) was obtained with variation in spot diameter. These values, and the extensive spread of a fluorescent dye (Lucifer Yellow) from the site of injection to neighboring cells, indicate that the horizontal cells of the all-rod retina of skate are well coupled electrically. Neither the receptive field properties nor the gap-junctional features of skate horizontal cells were influenced by the adaptive state of the retina: (a) the receptive field organization was unaffected by light adaptation, (b) similar dye coupling was seen in both dark- and light-adapted retinae, and (c) no significant differences were found in the gap-junctional particle densities measured in dark- and light-adapted retinas, i.e., 3,184 +/- 286/microns 2 (n = 8) and 3,073 +/- 494/microns 2 (n = 11), respectively. Moreover, the receptive fields of skate horizontal cells were not altered by either dopamine, glycine, GABA, or the GABAA receptor antagonists bicuculline and picrotoxin. We conclude that the rod-driven horizontal cells of the skate retina are tightly coupled to one another, and that the coupling is not affected by photic and pharmacological conditions that are known to modulate intercellular coupling between cone-driven horizontal cells in other species. PMID:1359000
Madejczyk, Michael S; Boyer, James L; Ballatori, Nazzareno
The liver is a major organ involved in regulating whole body manganese (Mn) homeostasis; however, the mechanisms of Mn transport across the hepatocyte basolateral and canalicular membranes remain poorly defined. To gain insight into these transport steps, the present study measured hepatic uptake and biliary excretion of Mn in an evolutionarily primitive marine vertebrate, the elasmobranch Leucoraja erinacea, the little skate. Mn was rapidly removed from the recirculating perfusate of isolated perfused skate livers in a dose-dependent fashion; however, only a small fraction was released into bile (skate hepatocytes in culture. Mn uptake was inhibited by a variety of divalent metals, but not by cesium. Analysis of the concentration-dependence of Mn uptake revealed of two components, with apparent K(m) values 1.1+/-0.1 microM and 112+/-29 microM. The K(m) value for the high-affinity component was similar to the measured skate blood Mn concentration, 1.9+/-0.5 microM. Mn uptake was reduced by nearly half when bicarbonate was removed from the culture medium, but was unaffected by a change in pH from 6.5 to 8.5, or by substitution of Na with Li or K. Mn efflux from the hepatocytes was also rapid, and was inhibited when cells were treated with 0.5 mM 2,4-dinitrophenol to deplete ATP levels. These data indicate that skate liver has efficient mechanisms for removing Mn from the sinusoidal circulation, whereas overall biliary excretion is low and appears to be mediated in part by an ATP-sensitive mechanism.
Reynisson, E; Thornór Marteinsson, V; Jónsdóttir, R; Magnússon, S H; Hreggvidsson, G O
To study the succession of cultivated and uncultivated microbes during the traditional curing process of skate. The microbial diversity was evaluated by sequencing 16Sr RNA clone libraries and cultivation in variety of media from skate samples taken periodically during a 9-day curing process. A pH shift was observed (pH 6·64-9·27) with increasing trimethylamine (2·6 up to 75·6 mg N per 100 g) and total volatile nitrogen (TVN) (from 58·5 to 705·8 mg N per 100 g) but with relatively slow bacterial growth. Uncured skate was dominated by Oceanisphaera and Pseudoalteromonas genera but was substituted after curing by Photobacterium and Aliivibrio in the flesh and Pseudomonas on the skin. Almost 50% of the clone library is derived from putative undiscovered species. Cultivation and enrichment strategies resulted in isolation of putatively new species belonging to the genera Idiomarina, Rheinheimera, Oceanisphaera, Providencia and Pseudomonas. The most abundant genera able to hydrolyse urea to ammonia were Oceanisphaera, Psychrobacter, Pseudoalteromonas and isolates within the Pseudomonas genus. The curing process of skate is controlled and achieved by a dynamic bacterial community where the key players belong to Oceanisphaera, Pseudoalteromonas, Photobacterium, Aliivibrio and Pseudomonas. For the first time, the bacterial population developments in the curing process of skate are presented and demonstrate a reservoir of many yet undiscovered bacterial species. No Claim to Norwegian Government works Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.
Matic, George T; Sommerfeldt, Mark F; Best, Thomas M; Collins, Christy L; Comstock, R Dawn; Flanigan, David C
The popularity of ice hockey has grown in recent years and injuries are a concern given the physical nature of the sport. We sought to report the rates, mechanisms, and severity of boys' US high school ice hockey injuries. We hypothesized that body checking would be a major source of injury and that concussions would be common. We also expected to find that competition would have a higher rate of injury than practice. Descriptive epidemiology study. Boys' US high school ice hockey injury data from 2008/2009 through 2012/2013 academic years were obtained from the National High School Sports-Related Injury Surveillance System, High School Reporting Information Online database. The primary outcome was rate of injury per 10,000 athlete exposures (AEs). Overall, 724 boys ice hockey injuries occurred during 311,817 AEs for an injury rate of 23.2 per 10,000 AEs. Injury rates were significantly higher during competition compared to practice (rate ratio = 7.8, 95% confidence interval: 6.5-9.4). Concussion was the most frequent injury reported at a rate of 6.4 per 10,000 AEs. Body checking was the mechanism of injury in over 46% of injuries. The head/face/neck region (33.8%) and upper arm/shoulder region (20.6%) were the most commonly injured body sites. Just over 6% of injuries resulted in surgical intervention. Injuries among high school ice hockey athletes are common. Increases in the number of high school ice hockey injuries will likely parallel the increase in high school ice hockey participation in the United States.
Brook, Emily M.; Kroshus, Emily; Hu, Caroline H.; Gedman, Marissa; Collins, Jamie E.; Matzkin, Elizabeth G.
Background: There are limited data on the incidence of concussion and concussion symptom nondisclosure among collegiate women’s ice hockey athletes. Purpose: To determine the incidence of sports-related concussion (SRC) in National Collegiate Athletic Association (NCAA) women’s ice hockey athletes. Study Design: Descriptive epidemiology study. Methods: An anonymous online survey was completed by 459 NCAA women’s ice hockey athletes. Players reported diagnosed concussions as well as incidents where they experienced an impact or blow to the head followed by symptoms associated with a concussion; reports spanned the duration of the 2014-2015 season and throughout players’ organized hockey career. Results: About half (n = 219, 47.7%) of respondents reported at least 1 diagnosed concussion over the duration of their entire organized ice hockey career. A total of 13.3% (n = 61) of respondents reported a diagnosed concussion during the 2014-2015 season. The incidence rate was 1.18 (95% CI, 0.92-1.51) per 1000 athlete-exposures to a game or practice and 0.58 (95% CI, 0.45-0.74) per 1000 hours of ice time. One-third (34.2%, n = 157) of players reported at least 1 impact where they experienced concussion-like symptoms during the 2014-2015 season; 82.8% of these players reported that they continued to play after at least 1 of these impacts, and 66.8% of players reported at least 1 impact where they never disclosed any symptoms. Conclusion: There is a high incidence of SRC in collegiate women’s ice hockey and a concerning level of symptom nondisclosure. Additional research is needed to understand the causes of concussion and reasons for the lack of symptom disclosure, including factors specific to female athletes and contextual issues specific to women’s collegiate ice hockey. PMID:28812036
The yearly cost of sports injuries, which affects Swedish society, is estimated to 3 billion SEK (460 million USD). Injuries in ice hockey represent at least 270 million SEK (42 million USD). Despite the high number of injuries, mouth and face guards are rarely used in Swedish ice hockey. The major aim of this study was to examine the attitudes of mouth and face guards in two ice hockey clubs in Sweden (one elite and one division 3 club). A second purpose was to determine why some players use mouth and face guards, while others do not. A third goal was to present a material that ice hockey clubs could use for further discussions. A phenomenographic analysis of focus groups interviews. The phenomenographic analysis of the data resulted in 12 categories. Within each category, issues, activities and engagement of the participants were described. Further, similarities and differences in the discussions between the elite club and the division 3 club were described. The following categories were found to engage the participants the most: 'Ice hockey is a high-velocity collision sport in which injuries are expected', 'Attitudes towards personal protection guards' and 'Suggested measures'. The participants were aware of the risk of playing ice hockey, but they know little about the consequences of a dental injury. Although ice hockey players wish to protect themselves, they refuse to accept just any mouth or face guard. Through the discussions about reducing dental and jaw injuries by routine use of protection devices, many reform proposals were presented that could be useful in future discussions. © 2013 John Wiley & Sons A/S.
Smith, Aynsley M; Stuart, Michael J; Greenwald, Richard M; Benson, Brian W; Dodick, David W; Emery, Carolyn; Finnoff, Jonathan T; Mihalik, Jason P; Roberts, William O; Sullivan, Carol-Anne; Meeuwisse, Willem H
: The objective of this proceeding was to integrate the concussion in sport literature and sport science research on safety in ice hockey to develop an action plan to reduce the risk, incidence, severity, and consequences of concussion in ice hockey. : A rationale paper outlining a collaborative action plan to address concussions in hockey was posted for review 2 mos before the "Ice Hockey Summit: Action on Concussion." Focused presentations devoted specifically to concussion in ice hockey were presented during the summit, and breakout sessions were used to develop strategies to reduce concussion in the sport. The proceedings and a detailed scientific review (a matrix of solutions) were written to disseminate the evidence-based information and resulting concussion reduction strategies. The manuscripts were reviewed by the authors, advisors, and contributors to ensure that the opinions and recommendations reflect the current level of knowledge on concussion in hockey. : Six components of a potential solution were articulated in the "Rationale" paper and became the topics for breakout groups that followed the professional scientific lectures. Topics that formed the core of the action plan were metrics and databases; recognizing, managing, and return to play; hockey equipment and ice arenas; prevention and education; rules and regulations; and expedient communication of the outcomes. The attendees in the breakout sessions identified the action items for each section. The most highly ranked action items were brought to a vote in the open assembly, using an Audience Response System. The strategic planning process was conducted to assess the following: "Where are we at?" "Where must we get to?" "What strategies are necessary to make progress on the prioritized action items?" : Three prioritized action items for each component of the solution and the percentage of the votes received are listed in the body of this proceeding.
Brook, Emily M; Kroshus, Emily; Hu, Caroline H; Gedman, Marissa; Collins, Jamie E; Matzkin, Elizabeth G
There are limited data on the incidence of concussion and concussion symptom nondisclosure among collegiate women's ice hockey athletes. To determine the incidence of sports-related concussion (SRC) in National Collegiate Athletic Association (NCAA) women's ice hockey athletes. Descriptive epidemiology study. An anonymous online survey was completed by 459 NCAA women's ice hockey athletes. Players reported diagnosed concussions as well as incidents where they experienced an impact or blow to the head followed by symptoms associated with a concussion; reports spanned the duration of the 2014-2015 season and throughout players' organized hockey career. About half (n = 219, 47.7%) of respondents reported at least 1 diagnosed concussion over the duration of their entire organized ice hockey career. A total of 13.3% (n = 61) of respondents reported a diagnosed concussion during the 2014-2015 season. The incidence rate was 1.18 (95% CI, 0.92-1.51) per 1000 athlete-exposures to a game or practice and 0.58 (95% CI, 0.45-0.74) per 1000 hours of ice time. One-third (34.2%, n = 157) of players reported at least 1 impact where they experienced concussion-like symptoms during the 2014-2015 season; 82.8% of these players reported that they continued to play after at least 1 of these impacts, and 66.8% of players reported at least 1 impact where they never disclosed any symptoms. There is a high incidence of SRC in collegiate women's ice hockey and a concerning level of symptom nondisclosure. Additional research is needed to understand the causes of concussion and reasons for the lack of symptom disclosure, including factors specific to female athletes and contextual issues specific to women's collegiate ice hockey.
Schmitt, Kai-Uwe; Muser, Markus H; Thueler, Hansjuerg; Bruegger, Othmar
One injury mechanism in ice hockey is impact with the boards. We investigated whether more flexible hockey boards would provide less biomechanical loading on impact than did existing (reference) boards. We conducted impact tests with a dynamic pendulum (mass 60 kg) and with crash test dummies (ES-2 dummy, 4.76 m/s impact speed). Outcomes were biomechanical loading experienced by a player in terms of head acceleration, impact force to the shoulder, spine, abdomen and pelvis as well as compression of the thorax. The more flexible board designs featured substantial displacement at impact. Some so-called flexible boards were displaced four times more than the reference board. The new boards possessed less stiffness and up to 90 kg less effective mass, reducing the portion of the board mass a player experienced on impact, compared with boards with a conventional design. Flexible boards resulted in a similar or reduced loading for all body regions, apart from the shoulder. The displacement of a board system did not correlate directly with the biomechanical loading. Flexible board systems can reduce the loading of a player on impact. However, we found no correlation between the displacement and the biomechanical loading; accordingly, displacement alone was insufficient to characterise the overall loading of a player and thus the risk of injury associated with board impact. Ideally, the performance of boards is assessed on the basis of parameters that show a good correlation to injury risk. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains the results of a tagging study being conducted on the Alaska skate (Bathyraja parmifera) in the eastern Bering Sea. The purpose of the study is...
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.
Stanula, Arkadiusz; Roczniok, Robert
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 (V̇O2max) 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.
King, Benjamin L.; Shi, Ling Fang; Kao, Peter; Clusin, William T.
Elasmobranchs detect small potentials using excitable cells of the ampulla of Lorenzini which have calcium-activated K+ channels, first described in l974. A distinctive feature of the outward current in voltage clamped ampullae is its apparent insensitivity to voltage. The sequence of a BK channel α isoform expressed in the ampulla of the skate was characterized. A signal peptide is present at the beginning of the gene. When compared to human isoform 1 (the canonical sequence), the largest difference was absence of a 59 amino acid region from the S8-S9 intracellular linker that contains the strex regulatory domain. The ampulla isoform was also compared with the isoform predicted˜ in late skate embryos where strex was also absent. The BK voltage sensors were conserved in both skate isoforms. Differences between the skate and human BK channel included alternative splicing. Alternative splicing occurs at seven previously defined sites that are characteristic for BK channels in general and hair cells in particular. Skate BK sequences were highly similar to the Australian ghost shark and several other vertebrate species. Based on alignment of known BK sequences with the skate genome and transcriptome, there are at least two isoforms of Kcnma1α expressed in the skate. One of the β subunits (β4), which is known to decrease voltage sensitivity, was also identified in the skate genome and transcriptome and in the ampulla. These studies advance our knowledge of BK channels and suggest further studies in the ampulla and other excitable tissues. PMID:26687710
King, Benjamin L; Shi, Ling Fang; Kao, Peter; Clusin, William T
Elasmobranchs detect small potentials using excitable cells of the ampulla of Lorenzini which have calcium-activated K(+) channels, first described in 1974. A distinctive feature of the outward current in voltage clamped ampullae is its apparent insensitivity to voltage. The sequence of a BK channel α isoform expressed in the ampulla of the skate was characterized. A signal peptide is present at the beginning of the gene. When compared to human isoform 1 (the canonical sequence), the largest difference was absence of a 59 amino acid region from the S8-S9 intra-cellular linker that contains the strex regulatory domain. The ampulla isoform was also compared with the isoform predicted in late skate embryos where strex was also absent. The BK voltage sensors were conserved in both skate isoforms. Differences between the skate and human BK channel included alternative splicing. Alternative splicing occurs at seven previously defined sites that are characteristic for BK channels in general and hair cells in particular. Skate BK sequences were highly similar to the Australian ghost shark and several other vertebrate species. Based on alignment of known BK sequences with the skate genome and transcriptome, there are at least two isoforms of Kcnma1α expressed in the skate. One of the β subunits (β4), which is known to decrease voltage sensitivity, was also identified in the skate genome and transcriptome and in the ampulla. These studies advance our knowledge of BK channels and suggest further studies in the ampulla and other excitable tissues. Copyright © 2015 Elsevier B.V. All rights reserved.
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.
Lee, Youn Young; Lee, Chang-Hyung; Lee, Sun Myung; Kim, Tae Gyu
Ice hockey is a competitive sport and ice hockey injuries can be influenced by many physical and psychological factors. Young ice hockey players are especially vulnerable to injury due to their relative lack of experience and rapid physical growth during their juvenile years. Up to now there has been no survey of the physical, psychological, and environmental etiological factors based on the Korean high school ice hockey players population. The purpose of our study was to evaluate, through a comprehensive survey, the incidence of ice hockey injuries according to age and the relationship between etiological factors and injuries in high school students. A cross-sectional study. One hundred nineteen ice hockey players in Korean high schools were recruited for this study. The study was conducted by a self-administered questionnaire survey. The researcher explained the purpose of the survey and how to fill it out. Individual questionnaires were distributed to participants. Chi-squared tests were used to evaluate the relationship between the independent and dependent values. There was a significant difference between a player's age and injury incidence (P = .018). The injury level of each position showed a significant tendency (P = .055). Age was highly correlated with the number of total injuries (P = .019). The average demographic characteristics of those surveyed were age (16.7 years), play line (2.2), height (174.8 cm), weight (69.6 kg), and body mass index (23.4). The shoulder was the most frequent injury area and the knee was the most common cause of hospital visits. There was a higher injury incidence in older groups; however, there was no correlation with body mass index, position, and play line. The causative factors were divided into physical factors, psychological factors, and environmental factors. Generally, 3 factors were not closely regarded as etiologic factors of ice hockey injury. However, deficiency of fitness in the physical factor, aggressiveness in
Roczniok, R; Stanula, A; Maszczyk, A; Mostowik, A; Kowalczyk, M; Fidos-Czuba, O; Zając, A
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.
Tuominen, Markku; Stuart, Michael J; Aubry, Mark; Kannus, Pekka; Parkkari, Jari
Information on ice hockey injuries at the international level is very limited. The aim of the study was to analyse the incidence, type, mechanism and severity of ice hockey injuries in men's international ice hockey tournaments. All the injuries in men's International Ice Hockey Federation World Championship tournaments over a 7-year period were analysed using a strict definition of injury, standardised reporting strategies and an injury diagnosis made by a team physician. 528 injuries were recorded in games resulting in an injury rate of 14.2 per 1000 player-games (52.1/1000 player-game hours). Additionally, 27 injuries occurred during practice. For WC A-pool Tournaments and Olympic Winter Games (OWG) the injury rate was 16.3/1000 player-games (59.6/1000 player-game hours). Body checking, and stick and puck contact caused 60.7% of the injuries. The most common types of injuries were lacerations, sprains, contusions and fractures. A laceration was the most common facial injury and was typically caused by a stick. The knee was the most frequently injured part of the lower body and the shoulder was the most common site of an upper body injury. Arenas with flexible boards and glass reduced the risk of injury by 29% (IRR 0.71, (95% CI 0.56 to 0.91)). The incidence of injury during international ice hockey competition is relatively high. Arena characteristics, such as flexible boards and glass, appeared to reduce the risk of injury. 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.
Hoppe, M W; Freiwald, J; Baumgart, C; Born, D P; Reed, J L; Sperlich, B
The aim of this study was to test the hypothesis that a significant relationship exists between the level of core strength-endurance and key variables of endurance, strength, power, speed, and agility performance in male elite rink hockey players. Ten male elite rink hockey players of the German national team were tested for 1) time to exhaustion, maximum oxygen uptake, and running economy, 2) one repetition maximum bench press and half squat, 3) counter movement jump height, 4) 5 m, 10 m, and 20 m speed, and 5) 22 m agility. The rink hockey players were also tested for 6) ventral, lateral-left, lateral-right, and dorsal core strength-endurance using concentric-eccentric muscle tests. The level of total and ventral core strength-endurance was very largely correlated with maximum oxygen uptake (r=0.74 and r=0.71, both Pcore strength-endurance and time to exhaustion (r=0.66, P0.05). The findings from this study suggest that the level of core strength-endurance is largely to very largely correlated with key variables of endurance performance, but not significantly with strength, power, speed, or agility indicators in male elite rink hockey players. These findings should be noted by coaches and scientists when testing physical fitness or planning strength and conditioning programs for male elite rink hockey players.
Deits, Jeff; Yard, Ellen E.; Collins, Christy L.; Fields, Sarah K.; Comstock, R. Dawn
Abstract Context: Although the number of US ice hockey participants doubled from 1990 to 2006, no nationally representative studies have examined US ice hockey injuries among participants of all ages during this period. Objective: To describe patients with ice hockey injuries presenting to a representative sample of US emergency departments (EDs) from 1990 through 2006. Design: Prospective injury surveillance study. Setting: The US Consumer Product Safety Commission collects data from 100 nationally representative EDs via the National Electronic Injury Surveillance System (NEISS). Patients or Other Participants: Individuals injured while playing ice hockey and presenting to a NEISS-affiliated ED from 1990 through 2006. Main Outcome Measure(s): Incidence and patterns of ice hockey–related injuries. Results: From 1990 through 2006, 8228 patients with ice hockey–related injuries presented to NEISS-affiliated EDs, representing an estimated 302 368 ice hockey–related injuries sustained nationally during this time. Injuries occurred predominantly among males (93.5%). More than half of the injured were aged 9 to 14 years (28.9%) or 15 to 18 years (30.1%), and injury incidence in these age groups increased over the study period (P = .009 and P Ice hockey injury patterns vary by age and sex. Our findings indicate that many trips to the ED might be prevented by using protective equipment appropriately. PMID:20831391
Pauelsen, Mascha; Nyberg, Gusten; Tegner, Cecilia; Tegner, Yelverton
The aim of this study was to analyze the concussion incidence rate ratios across 29 seasons in a Swedish Hockey League team. Cohort study over 29 seasons within one Swedish elite series ice hockey team. All players who were part of one Swedish elite ice hockey team during the research period gave consent for participation in the study. Exposure to top-level Swedish ice hockey. Incidence rate ratio for concussion and rehabilitation periods due to concussion were calculated and analyzed. During the research period, 267 players in total were part of the team. A total of 1638 traumatic injuries were registered, of which 162 were concussions. Incidence rates (IRs) ranged from 0/1000 games during the first season to 118/1000 games for the final recorded season. The incidence rate ratio was 1.06 (confidence interval, 1.03-1.10) for the entire research period. A shift toward longer rehabilitation periods was discovered. This study showed a significant increase of concussion IR and a trend toward longer rehabilitation periods due to concussion. Possible risk factors were discussed. Risk behavior and rehabilitation protocols should be prioritized areas in the research of concussion in ice hockey.
Delaney, J Scott; Al-Kashmiri, Ammar; Correa, José A
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.
Rowan, Chip P; Kuropkat, Christiane; Gumieniak, Robert J; Gledhill, Norman; Jamnik, Veronica K
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.
Losnegard, T; Hallén, J
Cross-country skiers' VO2max is often measured during treadmill running. However, VO2max during treadmill skiing with the diagonal stride technique is higher, whereas it is lower during double poling, another classical style technique. How these values compare to VO2max during ski skating in elite cross country skiers is not known. Therefore, this study compared VO2max during treadmill uphill running and treadmill roller ski skating. Twenty-two males (21±2 years, 182±6 cm, 77±7 kg, VO2max running; 72.4±4.4 mL·kg-1·min-1) elite cross-country skiers and biathlon athletes underwent testing in both running and roller ski skating before (May) and at the end (October) of the preseason training. From May to October VO2max increased during running (3.1±4.5%, P=0.003, Effect size; ES=0.44, small) but not during roller ski skating (1.8±5.6%, P=0.13, ES=0.24, small). In May the subjects' VO2max during running was 1.7±4.7% higher compared to during roller ski skating (P=0.08, ES=0.24, small) while in October this difference was 3.0±5.0 % (Pski skating than during running and this relationship does not change during the pre-season training period.
Full Text Available This paper reports findings derived from a study of the impacts of climate change on winter outdoor skating activities in the Chinese park of Bei Hai from 1989 to 2015. Based on field observation data and in-depth interviews, it was concluded that the outdoor skating activities, with a history of more than 1000 years, are being threatened by the warming climate. The opening dates and duration times of skating over the last 26 years showed periodic variations over three-year cycles. Increases of temperatures by 1 °C in December were associated with a 3.80-day delay in the skating-field opening dates and a 4.49-day decrease in the operation duration times. In particular, climate change has resulted in a loss of the skating field area and a reduction in the operation duration times, and tourists are moving north for skating-related recreation or conducting alternative activities. The current adaptive strategies are not very effective.
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.
Christie, Sommer; di Fronso, Selenia; Bertollo, Maurizio; Werthner, Penny
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.
Full Text Available The aim of the research was to know the physical condition of female Hockey athletes of Central Java especially in cardio capacity endurance to participate in PON XIX West Java, 2016. The type of this research was quantitative descriptive, with 22 female athtletes as the population. The technique in data collection used was population research that is all samples in this study were taken all. The sampling method used was quantitative technique with descriptive approach. The result of this research was the average physical condition especially in endurance was tested using the MFT in the degrees of being. It was proven that the average VO2max of female Hockey athletes of Central Java was 39.6 ml/kg/min or 8.5 in MSFT reverse. The conclusion was the physical condition of the female Hockey athletes of Central Java who would attend PON XIX 2016 in West Java was in moderate level.
Dursun, Onur Burak; Erhan, Süleyman Erim; Ibiş, Esra Özhan; Esin, Ibrahim Selcuk; Keleş, Sadullah; Şirinkan, Ahmet; Yörük, Özgür; Acar, Ethem; Beyhun, Nazim Ercument
Physical exercise and sports have a key role in preventing physical and psychiatric problems in children. However, children with a disability often experience difficulty participating in physical activity due to a lack of suitable opportunities. Participation in an accessible sport is particularly important for these children, but studies examining which sports are beneficial for which disability groups are rare. In this study, we assessed the effects of ice skating on the psychological well-being, self-concept, and sleep quality of children with hearing or visual impairment. Forty students (20 visually impaired and 20 hearing impaired) aged 8-16 were included in a regular ice skating programme for three months. We examined the sleep quality, self-concept, and behavioural and emotional states of the children before and after participating in the programme. There was a significant improvement in self-concept, behavioural and emotional problems, and sleep quality (p sport alternatives that gives children the opportunity to exercise and have fun together. The results of this study revealed that regular ice skating programmes may have positive effects on the psychological well-being of children with hearing impairment. Despite some positive effects, caution must be use when including visually impaired children in ice skating programmes. Generalization of the study's outcomes is limited as the study group were residential students enrolled in special education institutions for children who are blind or deaf. Ice skating is a community-based sport and a popular leisure activity that can also have benefits for people with disabilities. Ice skating and children with hearing impairment: Self-concept, behavioural and emotional problems, and sleep quality of the children with hearing impairment significantly improved after ice skating. Ice skating programmes may be considered as a rehabilitation alternative for children with hearing impairment. Ice skating and children with
Wilcox, Bethany J; Machan, Jason T; Beckwith, Jonathan G; Greenwald, Richard M; Burmeister, Emily; Crisco, Joseph J
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 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.
Brunner, Romana; Maffiuletti, Nicola A; Casartelli, Nicola C; Bizzini, Mario; Sutter, Reto; Pfirrmann, Christian W; Leunig, Michael
Femoroacetabular impingement (FAI), which is highly prevalent in adult ice hockey players, is often associated with negative clinical and functional outcomes. It is unclear, however, whether FAI-related bony deformities and symptoms may lead to functional alterations as reflected in hip muscle strength, range of motion (ROM), and on-ice physical performance in youth ice hockey players. Compared with players with neither structural signs nor symptoms related to FAI, players with symptomatic FAI would show hip muscle weakness and reduced hip ROM, which would in turn affect ice hockey physical performance. Controlled laboratory study. A total of 74 young male ice hockey players were evaluated bilaterally for passive hip internal rotation ROM by use of a hip examination chair. Only the side with less internal rotation ROM was further investigated. FAI-related bony deformities were evaluated with magnetic resonance imaging (MRI). The involved hip was classified as symptomatic or asymptomatic based on the presence of hip pain during exercise and results from the flexion/adduction/internal rotation (FADIR) provocation test. Hip muscle strength, passive hip ROM, and on-ice physical performance were compared between players with no FAI, players with asymptomatic MRI-positive FAI, and players with symptomatic FAI. Fifty of 74 players (68%) had FAI-related bony deformities, of whom 16 (22%) were symptomatic. Hip muscle strength, hip ROM, and on-ice physical performance did not differ significantly between players with no FAI and those with asymptomatic or symptomatic FAI. Despite a high prevalence of FAI-related bony deformities, youth ice hockey players with asymptomatic or symptomatic FAI did not show functional impairments in terms of hip muscle strength, hip ROM, or on-ice physical performance. Hip muscle strength, passive hip ROM, and on-ice physical performance do not seem to discriminate for FAI-related signs and symptoms in young male ice hockey players. © 2015 The
Brainard, Lindley L.; Beckwith, Jonathan G.; Chu, Jeffrey J.; Crisco, Joseph J.; McAllister, Thomas W.; Duhaime, Ann-Christine; Maerlender, Arthur C.; Greenwald, Richard M.
Purpose This study aims to quantify the frequency, magnitude, and location of head impacts sustained by male and female collegiate ice hockey players over two seasons of play. Methods Over two seasons, 88 collegiate athletes (51 female, 37 male) on two female and male NCAA varsity ice hockey teams wore instrumented helmets. Each helmet was equipped with 6 single-axis accelerometers and a miniature data acquisition system to capture and record head impacts sustained during play. Data collected from the helmets were post-processed to compute linear and rotational acceleration of the head as well as impact location. The head impact exposure data (frequency, location, and magnitude) were then compared across gender. Results Female hockey players experienced a significantly lower (p 0.278) for all locations except the right side of the head, where males received fewer impacts than females (p = 0.031). Female hockey players were 1.1 times more likely than males to sustain an impact less than 50 g while males were 1.3 times more likely to sustain an impact greater than 100 g. Similarly, males were 1.9 times more likely to sustain an impact with peak rotational acceleration greater than 5,000 rad/s2 and 3.5 times more likely to sustain an impact greater than 10,000 rad/s2. Conclusions Although the incidence of concussion has typically been higher for female hockey players than male hockey players, female players sustain fewer impacts and impacts resulting in lower head acceleration than males. Further study is required to better understand the intrinsic and extrinsic risk factors that lead to higher rates of concussion for females that have been previously reported. PMID:21716150
Ángel Cartés, Miguel
En este artículo queremos presentar un deporte nacido de la adaptación del hockey sobre hielo, hecha a propuesta de S.O. Canadá para mejorar el nivel de participación en los campeonatos de invierno de Special Olympics. Con la adaptación del suelo (cualquier pista deportiva), del material (stick y disco), proceso de aprendizaje, normativa técnica, reglamentación y la exclusión de los patines, nació el hockey interior como un deporte colectivo de 6 jugadores en el campo con un mínimo de 8 jugad...
Guillem Trabal Tañá
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 entrev...
Branfield, A S
In the tough, competitive environment of international ice hockey, it is vital that a player who sustains a minor facial laceration is returned to play as soon as possible. A method of wound closure that is fast to apply, water resistant, and effective was sought. Dermabond, a cyanoacrylate tissue adhesive, was selected for use during the 2002 International Ice Hockey Federation World Championships for the closure of selected facial wounds. The wounds were all closed using prescribed aseptic techniques. The results are presented and discussed. The tissue adhesive met the criteria set out.
Hechter, Richard P.
With the increased availability of modern technology and handheld probeware for classrooms, the iPad1 and the Video Physics2 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 phenomena using modern technologies to complement theoretical plots. This activity acknowledges hockey players' implicit understanding of the launch angle and initial velocity of a saucer pass as basic projectile motion while engaging students in authentic physics-based problem solving.
Rousseau, Philippe; Hoshizaki, Thomas Blaine; Gilchrist, M. D.
Many studies have assessed the ability of hockey helmets to protect against falls and collisions, yet none have addressed the injury risk associated with puck impacts. Thus, the purpose of this study was to document the capacity of a typical vinyl nitrile ice hockey helmet to reduce head accelerations and brain deformation caused by a puck impact. A bare and a helmeted Hybrid III male 50th percentile headform was struck with a puck three times to the forehead at 17, 23, 29, 35, and 41 m/s usi...
Tomana, Mitsuru; Parton, Angela; Barnes, David W.
Cartilaginous fish, especially sharks, rays and skates (elasmobranchs) hold interest as comparative models in immunology because they are thought to be among the organisms most closely related to the ancestor animal that first developed acquired immunity. The aim of this study was to improve methods used for the purification of viable leucocytes from peripheral blood of elasmobranchs. Here we describe modifications of density gradient centrifugation and medium formulation that improve isolation and analysis of highly-purified leucocytes from peripheral blood of a model elasmobranch, Leucoraja erinacea, the little skate. These techniques contribute to the preparation of elasmobranch immune cells that can be reliably analyzed by a variety of means, including the study of immune function. PMID:18474431
Maxwell, Erin E; Fröbisch, Nadia B; Heppleston, Audrey C
The ontogeny of the northwestern Atlantic batoid, Leucoraja ocellata, is described with special focus on the development of skate specific morphologies and the development of the fins. The results show that the sequence of events involving the early outgrowth of the paired fins and the initial development of the pharyngeal region is remarkably constant in skates, holocephalians, and sharks. However, differences exist in timing of the reshaping of the mandibular arch region, development of branchial filaments, median fins, denticles, and the order of branchial cleft formation. Despite the similarities of early events related to development of the branchial region and initial outgrowth of the fins, later stages are increasingly characterized by taxon-specific morphologies making a universal staging table for chondrichthyans less applicable. The staging table presented in this study represents an important resource for future studies on batoid embryology.
Vargas-Caro, Carolina; Bustamante, Carlos; Bennett, Michael B; Ovenden, Jennifer R
The yellownose skate Zearaja chilensis is endemic to South America. The species is the target of a valuable commercial fishery in Chile, but is highly susceptible to over-exploitation. The complete mitochondrial genome was described from 694,593 sequences obtained using Ion Torrent Next Generation Sequencing. The total length of the mitogenome was 16,909 bp, comprising 2 rRNAs, 13 protein-coding genes, 22 tRNAs and 2 non-coding regions. Comparison between the proposed mitogenome and one previously described from "raw fish fillets from a skate speciality restaurant in Seoul, Korea" resulted in 97.4% similarity, rather than approaching 100% similarity as might be expected. The 2.6% dissimilarity may indicate the presence of two separate stocks or two different species of, ostensibly, Z. chilensis in South America and highlights the need for caution when using genetic resources without a taxonomic reference or a voucher specimen.
Ricci, Francesco; Frosali, Giovanni
Multibody systems usually give rise to complex nonlinear dynamics, and the bicycle is not an exception. Even a simple model as the Two-Mass-Skate presents a long expression of the kinetic energy, making difficult to write explicitly the equations of motion. Instead of linearising or approximating the model, we will overcome this issue by using a functional expression of the kinetic energy. With introduction of appropriate nonlinear functions, the equations of motion are written in a form that...
Duckett, Drew J L; Naylor, Gavin J P
Chondrichthyes are a highly threatened class of organisms, largely due to overfishing and other human activities. The present study describes the complete mitochondrial genome (16,750 bp) of the endangered spotback skate, Atlantoraja castelnaui. The mitogenome is arranged in a typical vertebrate fashion, containing 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and 1 control region.
Anderson, W Gary; Leprince, Jérôme; Conlon, J Michael
A bradykinin (BK)-related peptide was isolated from heat-denaturated plasma from an elasmobranch fish, the little skate, Leucoraja erinacea after incubation with porcine pancreatic kallikrein. The primary structure of the peptide (H-Gly-Ile-Thr-Ser-Trp-Leu-Pro-Phe-OH; skate BK) shows limited structural similarity to the mammalian B1 receptor agonist, des-Arg(9)-BK. The myotropic activities of synthetic skate BK, and the analog skate [Arg(9)]BK, were examined in isolated skate vascular and intestinal smooth muscle preparations. Skate BK produced a concentration-dependent constriction of the mesenteric artery (EC(50)=4.37x10(-8)M; maximum response=103.4+/-10.23% of the response to 60mM KCl) but the response to skate [Arg(9)]BK was appreciably weaker (response to 10(-6)M=73.0+/-23.4% of the response to 60mM KCl). Neither the first branchial gill arch nor the ventral aorta responded to either purified peptide. Skate BK also produced a concentration-dependent constriction of intestinal smooth muscle preparations (EC(50)=2.74x10(-7)M; maximum response 31.0+/-12.2% of the response to 10(-5)M acetylcholine). Skate [Arg(9)]BK was without effect on the intestinal preparation. The data provide evidence for the existence of the kallikrein-kinin system in a phylogenetically ancient vertebrate group and the greater potency of skate BK compared with the analog skate [Arg(9)]BK suggests that the receptor mediating vascular responses resembles the mammalian B1 receptor more closely than the B2 receptor.
Mcphie, R P; Campana, S E
Four of the most common species of skate (Rajidae) were studied off eastern Canada to determine if their reproductive characteristics were linked to their population trajectories. The fecundity of the winter skate Leucoraja ocellata, the little skate Leucoraja erinacea, the thorny skate Amblyraja radiata and the smooth skate Malacoraja senta averaged between 41 and 56 egg cases per year for each species. For all species but L. ocellata, males matured at larger sizes and at later ages than females. Theoretical rates of population increase for non-equilibrium populations of L. ocellata (c. 0.07), M. senta (c. 0.14) and L. erinacea and A. radiata (c. 0.20) were low compared to most fishes, indicating that north-west Atlantic skates are intrinsically unproductive, yet are theoretically capable of supporting low-level fisheries. Nevertheless, the results of 36 years of research surveys indicate that the abundance of mature L. ocellata, A. radiata and M. senta all decreased by >90% since 1970, indicating that past fishing mortality (both directed and undirected) has outstripped the net productivity of the skate populations on the eastern Scotian Shelf. The relationship between maximum age (t(max)) and age of maturity (t(mat)) was a better predictor of population growth rate than was body size, with the species exhibiting the highest ratios of t(mat) :t(max) (L. ocellata = 0.68, M. senta = 0.66) having the lowest predicted population growth rates. L. ocellata appears to have the lowest productivity and has experienced the greatest population decline, thus raising concerns over its future status.
Henry, L-A; Stehmann, M F W; De Clippele, L; Findlay, H S; Golding, N; Roberts, J M
Highly localized concentrations of elasmobranch egg capsules of the deep-water skate Bathyraja richardsoni were discovered during the first remotely operated vehicle (ROV) survey of the Hebrides Terrace Seamount in the Rockall Trough, north-east Atlantic Ocean. Conductivity-temperature-depth profiling indicated that the eggs were bathed in a specific environmental niche of well-oxygenated waters between 4·20 and 4·55° C, and salinity 34·95-35·06, on a coarse to fine-grained sandy seabed on the seamount's eastern flank, whereas a second type of egg capsule (possibly belonging to the skate Dipturus sp.) was recorded exclusively amongst the reef-building stony coral Solenosmilia variabilis. The depths of both egg-laying habitats (1489-1580 m) provide a de facto refuge from fisheries mortality for younger life stages of these skates. © 2016 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.
Myklebust, Håvard; Gløersen, Øyvind; Hallén, Jostein
In regard to simplifying motion analysis and estimating center of mass (COM) in ski skating, this study addressed 3 main questions concerning the use of inertial measurement units (IMU): (1) How accurately can a single IMU estimate displacement of os sacrum (S1) on a person during ski skating? (2) Does incorporating gyroscope and accelerometer data increase accuracy and precision? (3) Moreover, how accurately does S1 determine COM displacement? Six world-class skiers roller-ski skated on a treadmill using 2 different subtechniques. An IMU including accelerometers alone (IMU-A) or in combination with gyroscopes (IMU-G) were mounted on the S1. A reflective marker at S1, and COM calculated from 3D full-body optical analysis, were used to provide reference values. IMU-A provided an accurate and precise estimate of vertical S1 displacement, but IMU-G was required to attain accuracy and precision of < 8 mm (root-mean-squared error and range of displacement deviation) in all directions and with both subtechniques. Further, arm and torso movements affected COM, but not the S1. Hence, S1 displacement was valid for estimating sideways COM displacement, but the systematic amplitude and timing difference between S1 and COM displacement in the anteroposterior and vertical directions inhibits exact calculation of energy fluctuations.
Panchuk, Derek; Vickers, Joan N; Hopkins, Will G
In interceptive timing tasks, long quiet eye (QE) durations at the release point, along with early tracking on the object, allow performers to couple their actions to the kinematics of their opponent and regulate their movements based on emergent information from the object's trajectory. We used a mobile eye tracker to record the QE of eight university-level ice hockey goaltenders of an equivalent skill level as they responded to shots that deflected off a board placed to their left or right, resulting in a trajectory with low predictability. QE behaviour was assessed using logistic regression and magnitude-based inference. We found that when QE onset occurred later in the shot (950 ± 580 ms, mean ± SD) there was an increase in the proportion of goals allowed (41% vs. 22%) compared to when QE onset occurred earlier. A shorter QE duration (1260 ± 630 ms) predicted a large increase in the proportion of goals scored (38% vs. 14%). More saves occurred when QE duration (2074 ± 47 ms) was longer. An earlier QE offset (2004 ± 66 ms) also resulted in a large increase in the number of goals allowed (37% vs. 11%) compared to a later offset (2132 ± 41 ms). Since an early, sustained QE duration contributed to a higher percentage of saves, it is important that coaches develop practice activities that challenge the goaltender's ability to fixate the puck early, as well as sustain a long QE fixation on the puck until after it is released from the stick.
Koerte, Inga K.; Kaufmann, David; Hartl, Elisabeth; Bouix, Sylvain; Pasternak, Ofer; Kubicki, Marek; Rauscher, Alexander; Li, David K. B.; Dadachanji, Shiroy B.; Taunton, Jack A.; Forwell, Lorie A.; Johnson, Andrew M.; Echlin, Paul S.; Shenton, Martha E.
Object The aim of this study was to investigate the effect of repetitive head impacts on white matter integrity that were sustained during 1 Canadian Interuniversity Sports (CIS) ice hockey season, using advanced diffusion tensor imaging (DTI). Methods Twenty-five male ice hockey players between 20 and 26 years of age (mean age 22.24 ± 1.59 years) participated in this study. Participants underwent pre- and postseason 3-T MRI, including DTI. Group analyses were performed using paired-group tract-based spatial statistics to test for differences between preseason and postseason changes. Results Tract-based spatial statistics revealed an increase in trace, radial diffusivity (RD), and axial diffusivity (AD) over the course of 1 season. Compared with preseason data, postseason images showed higher trace, AD, and RD values in the right precentral region, the right corona radiata, and the anterior and posterior limb of the internal capsule. These regions involve parts of the corticospinal tract, the corpus callosum, and the superior longitudinal fasciculus. No significant differences were observed between preseason and postseason for fractional anisotropy. Conclusions Diffusion tensor imaging revealed changes in white matter diffusivity in male ice hockey players over the course of 1 season. The origin of these findings needs to be elucidated. PMID:23199426
Sasaki, Takeshi; Pasternak, Ofer; Mayinger, Michael; Muehlmann, Marc; Savadjiev, Peter; Bouix, Sylvain; Kubicki, Marek; Fredman, Eli; Dahlben, Brian; Helmer, Karl G; Johnson, Andrew M; Holmes, Jeffrey D; Forwell, Lorie A; Skopelja, Elaine N; Shenton, Martha E; Echlin, Paul S; Koerte, Inga K
The aim of this study was to examine the brain's white matter microstructure by using MR diffusion tensor imaging (DTI) in ice hockey players with a history of clinically symptomatic concussion compared with players without a history of concussion. Sixteen players with a history of concussion (concussed group; mean age 21.7 ± 1.5 years; 6 female) and 18 players without a history of concussion (nonconcussed group; mean age 21.3 ± 1.8 years, 10 female) underwent 3-T DTI at the end of the 2011-2012 Canadian Interuniversity Sports ice hockey season. Tract-based spatial statistics (TBSS) was used to test for group differences in fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and the measure "trace," or mean diffusivity. Cognitive evaluation was performed using the Immediate Postconcussion Assessment and Cognitive Test (ImPACT) and the Sport Concussion Assessment Tool-2 (SCAT2). TBSS revealed a significant increase in FA and AD, and a significant decrease in RD and trace in several brain regions in the concussed group, compared with the nonconcussed group (p concussion may result in alterations of the brain's white matter microstructure in ice hockey players. Increased FA based on decreased RD may reflect neuroinflammatory or neuroplastic processes of the brain responding to brain trauma. Future studies are needed that include a longitudinal analysis of the brain's structure and function following a concussion to elucidate further the complex time course of DTI changes and their clinical meaning.
Stuart, M J; Smith, A
This 3-year prospective cohort observational analysis of elite amateur hockey players ranging in age from 17 to 20 years on a United States Hockey League team describes ice hockey injuries using a strict definition of injury, standardized reporting strategies, and diagnosis by a team physician. One hundred forty-two injuries were recorded for an on-ice injury rate of 9.4 per 1000 player hours. A player was 25 times more likely to be injured in a game (96.1 per 1000 player-game hours) than in practice (3.9 per 1000 player-practice hours). Game-related injuries were more frequent in the third period, and practice-related injuries occurred more often in the first third of the season. Collisions represented 51% of the total injuries. The most common types of injuries were strains, lacerations, contusions, and sprains. The face and the shoulder were most frequently injured. A facial laceration was the most common injury; acromioclavicular joint sprain was the second most common injury. Facial lacerations typically occurred in games and were stick related. Further research is necessary to determine if injuries in Junior A amateur ice hockey can be reduced by mandatory full facial protection, enforcement of existing rules, improvement in shoulder pad design, and by focusing more attention on stretching programs.
Elferink-Gemser, Marije Titia
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
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
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
Elferink-Gemser, Marije T.; Visscher, Chris; Lemmink, Koen A. P. M.; Mulder, Theo
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
Hancock, David J.; Ste-Marie, Diane M.
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…
Full Text Available Purpose. Motor coordination is proposed to be a relatively stable age-related construct, unlikely to be influenced by aligned experiential factors such as intensive sport-specific training. The purpose of the study is to investigate if there are differences in motor coordination abilities among young artistic gymnasts, swimmers, and ice hockey players.
Kitchen, Peter; Chowhan, James
More than 1 million Canadian adults play recreational ice hockey. Compared to elite players, very little is known about the physical and health characteristics of people who play the game for fun. Analyzing data from Statistics Canada's 2011/12 Canadian Community Health Survey, the paper found that there is an association between physically active males age 35 or over who play ice hockey regularly (at least once a week) and enhanced health more so than other physically active males. While these players are larger in body size, they have significantly lower rates of diabetes, high blood pressure and heart disease and report significantly higher rates of self-assessed health. Given the potential health benefits associated with this high intensity sport, the paper discusses ways in which participation can be promoted among less physically active adults and people who are new to the game or who have historically lower levels of participation including women and recent immigrants. Finally, the paper argues that compared to the very high costs associated with child and youth hockey, participation in adult recreational ice hockey is quite affordable.
Polites, Stephanie F; Sebastian, Arjun S; Habermann, Elizabeth B; Iqbal, Corey W; Stuart, Michael J; Ishitani, Michael B
Youth ice hockey is an exciting sport with growing participation in the United States. Updated assessment of injury patterns is needed to determine risk factors for severe injury and develop preventive efforts. The purpose of this study was to evaluate our experience as a level 1 pediatric trauma center in Minnesota treating injured youth ice hockey players. Children #18 years old who presented to our institution from July 1997 to July 2013 with an injury sustained while participating in ice hockey were identified. Patient demographic information, injury characteristics, and outcomes including use of computed tomography, hospital admission, and procedures were obtained. Age and gender-specific patterns were determined for injuries and outcomes. Over 16 years, 168 injuries in 155 children occurred, including 26 (15.5%) injuries in girls. Extremity injuries were most common, followed by traumatic brain injury. Injuries to the spine, face, and trunk were less common. Traumatic brain injury and injuries to the spine were most common in younger children (#14 years old) and girls, whereas injuries to the face were most common in older players ($15 years old). Most injuries resulted from intentional contact. Admission to the hospital was needed in 65 patients, including 14 (8.3%) who needed intensive care. A major procedure was needed by 23.2% of patients because of their injuries. Youth ice hockey trauma can be severe, necessitating a thorough evaluation of injured children. Injury patterns are influenced by age and gender, providing an opportunity for targeted preventive efforts.
Stark, Timothy W.; Tvoric, Bojan; Walker, Bruce; Noonan, Dom; Sibla, Janeene
The purpose of this study was to investigate the potential for improving hockey players' performance using a weighted implement on the ice. Forty-eight players were tested using a grip strength dynamometer. They also were assessed on their abilities to stick-handle. The participants were randomly placed into a control or research group. The…
Weaving, Charlene; Roberts, Samuel
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…
Skovereng, Knut; Ettema, Gertjan; Welde, Boye; Sandbakk, Øyvind
Ice sledge hockey is a popular paralympic team sport where players rely entirely on their upper body to propel themselves rapidly across the ice surface. The isolated and repetitive poling movements provide a good model for examining upper-body sprint ability and the related movement and strength characteristics. Therefore, the purpose of the present study was to investigate the relationship between upper-body maximal strength, power, and sprint performance in ice sledge hockey. Thirteen male ice sledge hockey players from the Norwegian national team performed three 30-m maximal sprint tests recorded by fixed light sensors. The best 30-m time for each subject was used for further analyses, and the sprint was analyzed more in detail for the first and last 10-m split times and kinematics (cycle length and rate) using photocells and 2-dimensional video analysis. One repetition maximum (1RM) strength and peak power were assessed in the bench press, bench pull, and pull-down exercises using a barbell and a linear encoder. Both 1RM strength and peak power for all the 3 strength exercises correlated significantly with the total sprint time (-0.75 ice sledge hockey.
Nelson, Lee J.; Potrac, Paul; Groom, Ryan
The aim of this paper was to provide some rich insights into how an elite ice-hockey player responded to his coaches' pedagogical delivery of video-based feedback sessions. Data for this study were gathered through a series of in-depth, semi-structured interviews and a reflective log relating to those interviews. The interviews were transcribed…
Darrah, Shaun D; Dicianno, Brad E; Berthold, Justin; McCoy, Andrew; Haas, Matthew; Cooper, Rory A
To determine whether sledge hockey players with physical disability have higher average seated pressures compared to non-disabled controls. Fifteen age-matched controls without physical disability and 15 experimental participants with physical disability were studied using a pressure mapping device to determine risk for skin pressure ulceration and the impact of cushioning and knee angle positioning on seated pressure distributions. Regardless of participant group, cushioning, or knee angle, average seated pressures exceeded clinically acceptable seated pressures. Controls had significantly higher average seated pressures than the disability group when knees were flexed, both with the cushion (p = 0.013) and without (p = 0.015). Knee extension showed significantly lower average pressures in controls, both with the cushion (p hockey players utilize positioning with larger knee flexion angles. Implications for Rehabilitation Ice sledge hockey is a fast growing adaptive sport. Adaptive sports have been associated with several positive improvements in overall health and quality of life, though may be putting players at risk for skin ulceration. Measured static seated pressure in sledges greatly exceeds current clinically accepted clinical guidelines. With modern improvements in wheelchair pressure relief/cushioning there are potential methods for improvement of elevated seated pressure in ice hockey sledges.
Cohn, Randy M; Strauss, Eric J; Jazrawi, Laith M; Feldman, Andrew J
Ice hockey is a fast paced sport with unique injury potential. There are no studies in the literature that examine the shoulder strength and range of motion in this population. Players on a single professional ice hockey team underwent a comprehensive examination of shoulder motion and strength. Shoulder motion and strength between right and left extremities were compared within athletes. Comparisons were made between right and left handed players, players that shoot right versus left handed, and by position. Within individual athletes, there was no difference in motion or strength between right and left shoulders. There was no difference in motion or strength between the dominant and non-dominant shoulder and players that shoot right versus left handed. Defensemen had a statistically significant increase in external rotation with the arm at the side for the left shoulder (66° versus 55°, p = 0.02) and a trend towards increased external rotation with the arm at the side for the right shoulder (65° versus 56°, p = 0.07). In professional ice hockey players, there is no difference in shoulder motion and strength between the right and left upper extremity. Ice hockey defensemen may have more external rotation with the arm at the side than forward.
Bhat, Rashi; Moiz, Jamal Ali
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.
Hechter, Richard P.
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…
Full Text Available O objetivo deste estudo foi apresentar elementos da esportivização da prática cultural skate (1960-1990, como conhecimento para o entendimento da relação entre o micro e o macro processo sócio-histórico do skate. Como fonte de pesquisa histórica para a esportivização do skate no Brasil, dimensão macro, utilizamos a Revista Tribo Skate e para a de Piracicaba/SP, dimensão micro, entrevistamos dois colaboradores a partir do método da história oral. Os resultados evidenciaram que o skate surgiu para gerar fortes tensões agradáveis, suas formas de lazer precedem as formas esportivas e, guardadas as particularidades, os seus processos macro e micro-históricos são interdependentes.
O objetivo deste estudo foi apresentar elementos da esportivização da prática cultural skate (1960-1990), como conhecimento para o entendimento da relação entre o micro e o macro processo sócio-histórico do skate. Como fonte de pesquisa histórica para a esportivização do skate no Brasil, dimensão macro, utilizamos a Revista Tribo Skate e para a de Piracicaba/SP, dimensão micro, entrevistamos dois colaboradores a partir do método da história oral. Os resultados evidenciaram que o skate surgiu ...
Pasternak, Ofer; Koerte, Inga K; Bouix, Sylvain; Fredman, Eli; Sasaki, Takeshi; Mayinger, Michael; Helmer, Karl G; Johnson, Andrew M; Holmes, Jeffrey D; Forwell, Lorie A; Skopelja, Elaine N; Shenton, Martha E; Echlin, Paul S
Concussion is a common injury in ice hockey and a health problem for the general population. Traumatic axonal injury has been associated with concussions (also referred to as mild traumatic brain injuries), yet the pathological course that leads from injury to recovery or to long-term sequelae is still not known. This study investigated the longitudinal course of concussion by comparing diffusion MRI (dMRI) scans of the brains of ice hockey players before and after a concussion. The 2011-2012 Hockey Concussion Education Project followed 45 university-level ice hockey players (both male and female) during a single Canadian Interuniversity Sports season. Of these, 38 players had usable dMRI scans obtained in the preseason. During the season, 11 players suffered a concussion, and 7 of these 11 players had usable dMRI scans that were taken within 72 hours of injury. To analyze the data, the authors performed free-water imaging, which reflects an increase in specificity over other dMRI analysis methods by identifying alterations that occur in the extracellular space compared with those that occur in proximity to cellular tissue in the white matter. They used an individualized approach to identify alterations that are spatially heterogeneous, as is expected in concussions. Paired comparison of the concussed players before and after injury revealed a statistically significant (p brain tissue. Fractional anisotropy was significantly increased, but this change was no longer significant following the free-water elimination. Concussion during ice hockey games results in microstructural alterations that are detectable using dMRI. The alterations that the authors found suggest decreased extracellular space and decreased diffusivities in white matter tissue. This finding might be explained by swelling and/or by increased cellularity of glia cells. Even though these findings in and of themselves cannot determine whether the observed microstructural alterations are related to long
Cusimano, Michael D; Topolovec-Vranic, Jane; Zhang, Stanley; Mullen, Sarah J; Wong, Mattew; Ilie, Gabriela
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.
Guillem Trabal Tañá
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.
Del Coso, Juan; Portillo, Javier; Salinero, Juan José; Lara, Beatriz; Abian-Vicen, Javier; Areces, Francisco
The aim of this investigation was to determine the efficacy of a caffeine-containing energy drink to improve physical performance of elite field hockey players during a game. On 2 days separated by a week, 13 elite field hockey players (age and body mass = 23.2 ± 3.9 years and 76.1 ± 6.1 kg) ingested 3 mg of caffeine per kg of body mass in the form of an energy drink or the same drink without caffeine (placebo drink). After 60 min for caffeine absorption, participants played a simulated field hockey game (2 × 25 min). Individual running pace and instantaneous speed during the game were assessed using GPS devices. The total number of accelerations and decelerations was determined by accelerometry. Compared with the placebo drink, the caffeinated energy drink did not modify the total distance covered during the game (6,035 ± 451 m and 6,055 ± 499 m, respectively; p = .87), average heart rate (155 ± 13 beats per min and 158 ± 18 beats per min, respectively; p = .46), or the number of accelerations and decelerations (697 ± 285 and 618 ± 221, respectively; p = .15). However, the caffeinated energy drink reduced the distance covered at moderate-intensity running (793 ± 135 and 712 ± 116, respectively; p = .03) and increased the distance covered at high-intensity running (303 ± 67 m and 358 ± 117 m; p = .05) and sprinting (85 ± 41 m and 117 ± 55 m, respectively; p = .02). Elite field hockey players can benefit from ingesting caffeinated energy drinks because they increase the running distance covered at high-intensity running and sprinting. Increased running distance at high speed might represent a meaningful advantage for field hockey performance.
Cusimano, Michael D; Ilie, Gabriela; Mullen, Sarah J; Pauley, Christopher R; Stulberg, Jennifer R; Topolovec-Vranic, Jane; Zhang, Stanley
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.
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.
Decloe, Melissa D; Meeuwisse, Willem H; Hagel, Brent E; Emery, Carolyn A
The objectives of this cohort study were to examine the rate, types, mechanisms and risk factors for injury in female youth (ages 9-17) ice hockey players in the Girls Hockey Calgary Association. The main outcome was ice hockey injury, defined as any injury occurring during the 2008/2009 season that required medical attention, and/or removal from a session and/or missing a subsequent session. Potential risk factors included age group, level of play, previous injury, ice hockey experience, physical activity level, weight, height, position of play and menarche. Incidence rate ratios (IRR) were estimated with Poisson Regression adjusted for cluster (team). Exposure data were collected for every session for each participating player. Twenty-eight teams (n=324) from Atom (ages 9-10), PeeWee (11-12), Bantam (13-14) and Midget (15-17) participated with 53 reported injuries. The overall injury rate was 1.9 injuries/1000 player-hours (95% CI 1.4 to 2.7). Previous injury (IRR=2.7, 95% CI 1.7 to 4.3), games (IRR=2.1, 95% CI 1.1 to 4.2), menarche (PeeWee) (IRR=4.1, 95% CI 1.0 to 16.8) were significant risk factors. In Midget, the more elite divisions were associated with a lower injury risk (A-IRR=0.2, 95% CI 0.1 to 0.5) (AAA-IRR=0.5, 95% CI 0.2 to 0.9). Injury rates were lower in this study than previously found in male youth and women's ice hockey populations. Previous injury and game play as risk factors are consistent with the literature. Menarche as a risk factor is a new finding in this study. This research will inform future studies of the development of injury prevention strategies in this population.
Cusimano, Michael D; Nastis, Sofia; Zuccaro, Laura
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. 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. 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. 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.
Peterson, Ben J; Fitzgerald, John S; Dietz, Calvin C; Ziegler, Kevin S; Baker, Sarah E; Snyder, Eric M
Peterson, BJ, Fitzgerald, JS, Dietz, CC, Ziegler, KS, Baker, SE, and Snyder, EM. Off-ice anaerobic power does not predict on-ice repeated shift performance in hockey. J Strength Cond Res 30(9): 2375-2381, 2016-Anaerobic power is a significant predictor of acceleration and top speed in team sport athletes. Historically, these findings have been applied to ice hockey although recent research has brought their validity for this sport into question. As ice hockey emphasizes the ability to repeatedly produce power, single bout anaerobic power tests should be examined to determine their ability to predict on-ice performance. We tested whether conventional off-ice anaerobic power tests could predict on-ice acceleration, top speed, and repeated shift performance. Forty-five hockey players, aged 18-24 years, completed anthropometric, off-ice, and on-ice tests. Anthropometric and off-ice testing included height, weight, body composition, vertical jump, and Wingate tests. On-ice testing consisted of acceleration, top speed, and repeated shift fatigue tests. Vertical jump (VJ) (r = -0.42; r = -0.58), Wingate relative peak power (WRPP) (r = -0.32; r = -0.43), and relative mean power (WRMP) (r = -0.34; r = -0.48) were significantly correlated (p ≤ 0.05) to on-ice acceleration and top speed, respectively. Conversely, none of the off-ice tests correlated with on-ice repeated shift performance, as measured by first gate, second gate, or total course fatigue; VJ (r = 0.06; r = 0.13; r = 0.09), WRPP (r = 0.06; r = 0.14; r = 0.10), or WRMP (r = -0.10; r = -0.01; r = -0.01). Although conventional off-ice anaerobic power tests predict single bout on-ice acceleration and top speed, they neither predict the repeated shift ability of the player, nor are good markers for performance in ice hockey.
Characterization of the functional and anatomical differences in the atrial and ventricular myocardium from three species of elasmobranch fishes: smooth dogfish (Mustelus canis), sandbar shark (Carcharhinus plumbeus), and clearnose skate (Raja eglanteria).
Larsen, Julie; Bushnell, Peter; Steffensen, John; Pedersen, Morten; Qvortrup, Klaus; Brill, Richard
We assessed the functional properties in atrial and ventricular myocardium (using isolated cardiac strips) of smooth dogfish (Mustelus canis), clearnose skate (Raja eglanteria), and sandbar shark (Carcharhinus plumbeus) by blocking Ca 2+ release from the sarcoplasmic reticulum (SR) with ryanodine and thapsigargin and measuring the resultant changes in contraction-relaxation parameters and the force-frequency relationship at 20 °C and 30 °C. We also examined ultrastructural differences with electron microscopy. In tissues from smooth dogfish, net force (per cross-sectional area) and measures of the speeds of contraction and relaxation were all higher in atrial than ventricular myocardium at both temperatures. Atrial-ventricular differences were evident in the other two species primarily in measures of the rates of contraction and relaxation. Ryanodine-thapsigargin treatment reduced net force and its maximum positive first derivative (i.e., contractility), and increased time to 50 % relaxation in atrial tissue from smooth dogfish at 30 °C. It also increased times to peak force and half relaxation in clearnose skate atrial and ventricular tissue at both temperatures, but only in atrial tissue from sandbar shark at 30 °C; indicating that SR involvement in excitation-contraction (EC) coupling is species- and temperature-specific in elasmobranch fishes, as it is in teleost fishes. Atrial and ventricular myocardium from all three species displayed a negative force-frequency relationship, but there was no evidence that SR involvement in EC coupling was influenced by heart rate. SR was evident in electron micrographs, generally located in proximity to mitochondria and intercalated discs, and to a lesser extent between the myofibrils; with mitochondria being more numerous in ventricular than atrial myocardium in all three species.
Last, Peter R; Stewart, Andrew L; Séret, Bernard
A single specimen of a new Bathyraja skate was collected by the authors in 2003 during a survey of the deepwater biota of the northern Tasman Sea by the New Zealand FRV Tangaroa. This skate, labelled the 'blonde skate' by voyage participants, is uniformly white on all surfaces of the body and the skin is partly translucent. It belongs to a subgroup of Bathyraja with a large, almost smooth, quadrangular disc and well-developed and equally spaced median tail thorns. Other similar and probably closely related Bathyraja specimens have been caught in seas to the south of New Zealand since the discovery of this species, but their identity is yet to be confirmed.
... : 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...
Full Text Available Purpose: determination of correlation’s degree between speed, power and speed-power abilities of professional hockey players on ice and out of ice. Material: 65 professional hockey players of age from 16 to 33 years old were tested. 75 highly qualified coaches were questioned. Results: The found out interconnections between 11 indicators of speed, power and speed power qualities supplement knowledge about transfer physical qualities. We detected high interconnection between speed and speed-power abilities, manifested by sportsmen in exercises on ice and on land. We registered moderate level of interconnection between static (absolute power and speed abilities of hockey players. We proved hypothesis about possibility of start speed (power transfer in different conditions of its manifestation. Conclusions: the received data permit to correct hockey players’ training program, considering new knowledge about transfer of one or the other physical qualities on sportsmen’s training.
Suzuki, Shunsuke; Kasai, Kentaro; Yamauchi, Kiyoshi
Transthyretin (TTR) diverged from an ancestral 5-hydroxyisourate hydrolase (HIUHase) by gene duplication at some early stage of chordate evolution. To clarify how TTR had participated in the thyroid system as an extracellular thyroid hormone (TH) binding protein, TH binding properties of recombinant little skate Leucoraja erinacea TTR was investigated. At the amino acid level, skate TTR showed 37-46% identities with the other vertebrate TTRs. Because the skate TTR had a unique histidine-rich segment in the N-terminal region, it could be purified by Ni-affinity chromatography. The skate TTR was a 46-kDa homotetramer of 14.5kDa subunits, and had one order of magnitude higher affinity for 3,3',5-triiodo-l-thyronine (T3) and some halogenated phenols than for l-thyroxine. However, the skate TTR had no HIUHase activity. Ethylenediaminetetraacetic acid (EDTA) treatment inhibited [(125)I]T3 binding activity whereas the addition of Zn(2+) to the EDTA-treated TTR recovered [(125)I]T3 binding activity in a Zn(2+) concentration-dependent manner. Scatchard analysis revealed the presence of two classes of binding site for T3, with dissociation constants of 0.24 and 17nM. However, the high-affinity sites were completely abolished with 1mM EDTA, whereas the remaining low-affinity sites decreased binding capacity. The number of zinc per TTR was quantified to be 4.5-6.3. Our results suggest that skate TTR has tight Zn(2+)-binding sites, which are essential for T3 binding to at least the high-affinity sites. Zn(2+) binding to the N-terminal histidine-rich segment may play an important role in acquisition or reinforcement of TH binding ability during early evolution of TTR. Copyright © 2015 Elsevier Inc. All rights reserved.
Van Iterson, Erik H; Fitzgerald, John S; Dietz, Calvin C; Snyder, Eric M; Peterson, Ben J
Van Iterson, EH, Fitzgerald, JS, Dietz, CC, Snyder, EM, and Peterson, BJ. Reliability of triaxial accelerometry for measuring load in men's collegiate ice hockey. J Strength Cond Res 31(5): 1305-1312, 2017-Wearable microsensor technology incorporating triaxial accelerometry is used to quantify an index of mechanical stress associated with sport-specific movements termed PlayerLoad. The test-retest reliability of PlayerLoad in the environmental setting of ice hockey is unknown. The primary aim of this study was to quantify the test-retest reliability of PlayerLoad in ice hockey players during performance of tasks simulating game conditions. Division I collegiate male ice hockey players (N = 8) wore Catapult Optimeye S5 monitors during repeat performance of 9 ice hockey tasks simulating game conditions. Ordered ice hockey tasks during repeated bouts included acceleration (forward or backward), 60% top-speed, top-speed (forward or backward), repeated shift circuit, ice coasting, slap shot, and bench sitting. Coefficient of variation (CV), intraclass correlation coefficient (ICC), and minimum difference (MD) were used to assess PlayerLoad reliability. Test-retest CVs and ICCs of PlayerLoad were as follows: 8.6% and 0.54 for forward acceleration, 13.8% and 0.78 for backward acceleration, 2.2% and 0.96 for 60% top-speed, 7.5% and 0.79 for forward top-speed, 2.8% and 0.96 for backward top-speed, 26.6% and 0.95 for repeated shift test, 3.9% and 0.68 for slap shot, 3.7% and 0.98 for coasting, and 4.1% and 0.98 for bench sitting, respectively. Raw differences between bouts were not significant for ice hockey tasks (p > 0.05). For each task, between-bout raw differences were lower vs. MD: 0.06 vs. 0.35 (forward acceleration), 0.07 vs. 0.36 (backward acceleration), 0.00 vs. 0.06 (60% top-speed), 0.03 vs. 0.20 (forward top-speed), 0.02 vs. 0.09 (backward top-speed), 0.18 vs. 0.64 (repeated shift test), 0.02 vs. 0.10 (slap shot), 0.00 vs. 0.10 (coasting), and 0.01 vs. 0
Educating and training children in ice hockey is a responsible task. Coaches of youth players have to be mature people with well-developed values, sport-specific knowl-edge and an understanding in the development of children. This thesis gathers and presents both scientific data and practical experiences from ice hockey and sports in general with the purpose to help coaches to manage children more effectively. Three periods of child development are described. Early childhood (2-6 years of ...
Vargas-Caro, Carolina; Bustamante, Carlos; Lamilla, Julio; Bennett, Michael B; Ovenden, Jennifer R
The complete mitochondrial genome of the roughskin skate Dipturus trachyderma is described from 1 455 724 sequences obtained using Illumina NGS technology. Total length of the mitogenome was 16 909 base pairs, comprising 2 rRNAs, 13 protein-coding genes, 22 tRNAs and 2 non-coding regions. Phylogenetic analysis based on mtDNA revealed low genetic divergence among longnose skates, in particular, those dwelling the continental shelf and slope off the coasts of Chile and Argentina.
Full Text Available Methodology of competition activity of skilled fgure skaters is reasonable. The model of the special preparedness of future teachers is worked out. Maintenance and principles of process of teaching of students is worked out. Methodical bases of technology of teaching students to the construction of competition compositions are reasonable. The pedagogical departmental of students teaching is presented taking into account modern features and progress of fgure-skating trends on skates. Conception is based on a capture students professional knowledge, abilities and skills.
Full Text Available Purpose: to define the level of stress-stability of hockey players of high class and expose his influence on efficiency of competition activity of sportsmen. Materials and Methods: sixteen sportsmen of high class, taking part in the matches of the Kontinental hockey league (KXL for a club «Atlas» (Moscow obl. in a season 2013–2014, took part in researches The level of stress-stability of hockey players and his influence was analysed on efficiency of competition activity of sportsmen. Methods were used: pedagogical supervisions and analysis of competition activity, psychological testing, analysis of data of the special scientific-methodical literature, an analysis of data is the Internet, methods of mathematical statistics. Results: it is set in researches, that the hockey players of high class have a moderate level of personality and situation anxiety, high motivation to success and propensity to the risk. Correlation analysis showed that the level of stress resistance affects the efficiency of hockey players technical and tactical actions in the game. What below for sportsmen the level of stress was marked, the higher there were indexes of the neglected pucks and effective transmissions in a match (r=–0,583, –0,542. Conclusions: the level of stress-stability of hockey players of high class influences on efficiency of competition activity of sportsmen. Can be drawn on the exposed results for the correction of psychological preparedness of sportsman.
Serra-Pereira, Bárbara; Erzini, Karim; Maia, Catarina; Figueiredo, Ivone
Understanding of spatio-temporal patterns of sensitive fish species such as skates (Rajidae) is essential for implementation of conservation measures. With insufficient survey data available for these species in Portuguese Continental waters, this study shows that fishery-dependent data associated with fishers' knowledge can be used to identify potential Essential Fish Habitats (EFH) for seven skate species. Sites with similar geomorphology were associated with the occurrence of juveniles and/or adults of the same group of species. For example, sites deeper than 100 m with soft sediment include predominantly adults of Raja clavata, and are the habitat for egg deposition of this species. Raja undulata and R. microocellata are the more coastal species, preferring sand or gravel habitats, while coastal areas with rocks and sand seabed are potential nursery areas for R. brachyura, R. montagui and R. clavata. The main output of this study is the identification of preferential fishing sites enclosing potential EFH for some species, associated with egg-laying and nursery grounds. The location of these areas will be considered for future seasonal closures, and studies will be conducted to evaluate the biological and socio-economic impacts of such measures. As in the past, fishermen will collaborate in the process of evaluating those impacts, since they have practical and applied knowledge that is extremely valuable for evaluating the advantages and disadvantages of such closures. In conclusion, this study is a first contribution to the understanding and identification of EFH for skate species, associated with nursery and egg deposition sites, with direct application to management.
Shahim, Pashtun; Tegner, Yelverton; Wilson, David H; Randall, Jeffrey; Skillbäck, Tobias; Pazooki, David; Kallberg, Birgitta; Blennow, Kaj; Zetterberg, Henrik
Lack of objective biomarkers for brain damage hampers acute diagnosis and clinical decision making about return to play after sports-related concussion. To determine whether sports-related concussion is associated with elevated levels of blood biochemical markers of injury to the central nervous system and to assess whether plasma levels of these biomarkers predict return to play in professional ice hockey players with sports-related concussion. Multicenter prospective cohort study involving all 12 teams of the top professional ice hockey league in Sweden, the Swedish Hockey League. Two hundred eighty-eight professional ice hockey players from 12 teams contesting during the 2012-2013 season consented to participate. All players underwent clinical preseason baseline testing regarding concussion assessment measures. Forty-seven players from 2 of the 12 ice hockey teams underwent blood sampling prior to the start of the season. Thirty-five players had a concussion from September 13, 2012, to January 31, 2013; of these players, 28 underwent repeated blood sampling at 1, 12, 36, and 144 hours and when the players returned to play. Total tau, S-100 calcium-binding protein B, and neuron-specific enolase concentrations in plasma and serum were measured. Concussed players had increased levels of the axonal injury biomarker total tau(median, 10.0 pg/mL; range, 2.0-102 pg/mL) compared with preseason values (median, 4.5pg/mL; range, 0.06-22.7 pg/mL) (P concussion(median, 0.075 μg/L; range, 0.037-0.24 μg/L) compared with preseason values (median,0.045 μg/L; range, 0.005-0.45 μg/L) (P concussion, and they decreased during rehabilitation. No significant changes were detected in the levels of neuron-specific enolase from preseason values (median, 6.5 μg/L; range,3.45-18.0 μg/L) to postconcussion values (median, 6.1 μg/L; range, 3.6-12.8 μg/L) (P = .10). Sports-related concussion in professional ice hockey players is associated with acute axonal and astroglial injury. This
Conrad, G. W.; Luer, C. A.; Paulsen, A. Q.; Funderburgh, J. L.; Spooner, B. S. (Principal Investigator)
Morphogenesis of the clearnose skate, Raja eglanteria, was not significantly inhibited as a result of 7 days of exposure to 1-2 mM selenate in the sea water during Days 59-69 of embryonic development (hatching would normally have occurred at 82 +/- 4 days of incubation). Although corneal transparency appeared normal in the eye, preliminary measurements of the thickness of Bowman's layer of the cornea suggested that it was significantly thinner in the corneas of embryos exposed to 1-2 mM selenate. Selenate is an ion reported to inhibit sulfation of glycosaminoglycans in connective tissue.
Kim B. Ritchie
Full Text Available Elasmobranchs represent a distinct group of cartilaginous fishes that harbor a remarkable ability to heal wounds rapidly and without infection. To date very little work has addressed this phenomenon although it is suggested that antibiotic capabilities associated with epidermal surfaces may be a factor. The study of benefits derived from mutualistic interactions between unicellular and multicellular organisms is a rapidly growing area of research. Here we survey and identify bacterial associates of three ray and one skate species in order to assess the potential for antibiotic production from elasmobranch associated bacteria as a novel source for new antibiotics.
Black, Amanda M; Hagel, Brent E; Palacios-Derflingher, Luz; Schneider, Kathryn J; Emery, Carolyn A
In 2013, Hockey Canada introduced an evidence-informed policy change delaying the earliest age of introduction to body checking in ice hockey until Bantam (ages 13-14) nationwide. To determine if the risk of injury, including concussions, changes for Pee Wee (11-12 years) ice hockey players in the season following a national policy change disallowing body checking. In a historical cohort study, Pee Wee players were recruited from teams in all divisions of play in 2011-2012 prior to the rule change and in 2013-2014 following the change. Baseline information, injury and exposure data for both cohorts were collected using validated injury surveillance. Pee Wee players were recruited from 59 teams in Calgary, Alberta (n=883) in 2011-2012 and from 73 teams in 2013-2014 (n=618). There were 163 game-related injuries (incidence rate (IR)=4.37/1000 game-hours) and 104 concussions (IR=2.79/1000 game-hours) in Alberta prior to the rule change, and 48 injuries (IR=2.16/1000 game-hours) and 25 concussions (IR=1.12/1000 game-hours) after the rule change. Based on multivariable Poisson regression with exposure hours as an offset, the adjusted incidence rate ratio associated with the national policy change disallowing body checking was 0.50 for all game-related injuries (95% CI 0.33 to 0.75) and 0.36 for concussion specifically (95% CI 0.22 to 0.58). Introduction of the 2013 national body checking policy change disallowing body checking in Pee Wee resulted in a 50% relative reduction in injury rate and a 64% reduction in concussion rate in 11-year-old and 12-year-old hockey players in Alberta. © 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.
Ballestero García, Enrique
El hockey sobre patins és un esport col•lectiu de col•laboració i oposició en el qual l’objectiu principal és marcar a porteria. Per això, s’utilitzen distintes tècniques de dispar: Pala i cullera. Els objectius d’aquesta tesi doctoral són contextualitzar i descriure la utilitat del dispar de Pala en el hockey sobre patins així com analitzar els factors que influeixen en la velocitat de la bolla durant la seva realització. Els resultats d’aquest treball suggereixen que la tècnica més utilitza...
Hensley, Craig P; Dirschl, Douglas R
Isolated cuneiform fractures are rare and are often missed on plain radiographs, leading to delayed diagnosis and delayed return to sport. The authors of this study present a 32-year-old male ice hockey player who sustained trauma to his dorsal midfoot from a slap shot. Radiographs were negative for fracture. After inability to wean out of the controlled ankle movement boot, magnetic resonance imaging was ordered, demonstrating a middle cuneiform fracture. The patient was seen in physical therapy, where aquatic therapy, strength training, and cardiovascular conditioning were progressed. He was able to wean out of the controlled ankle movement boot at 7 weeks after injury and return to playing ice hockey. Here, we outline rehabilitation and a diagnostic and rehabilitative algorithm for those who sustain trauma to the dorsal midfoot with suspected fracture.
ADRIANO ALBUQUERQUE BARRETO
As Skate Plazas surgem no início dos anos 2000 como um modelo possível na construção de pistas de skate. Este modelo surgiu na perspectiva de uma construção cada vez mais semelhante dos lugares que se encontram nas ruas das cidades. Até então além dos obstáculos mais comuns encontrados nas ruas, como os caixotes, os trilhos e as escadas, as rampas faziam parte das pistas que vinham sendo construídas. Nos modelos mais recentes de Skate Plaza vemos com menor intensidade a este tipo de obs...
Perrotta, Andrew S; Taunton, Jack E; Koehle, Michael S; White, Matthew D; Warburton, Darren E R
This study examined the congruence between the prescribed and experienced heart rate derived training loads over a five week periodized mesocycle. Twenty-four elite female field hockey players training as part of a national team were monitored prior to an (FIH) Hockey World League tournament. Three on-field training sessions per week were prospectively designed focusing on technical, tactical, and physiologically-oriented hockey drills. A training load value, modelling the periodized weekly loading scheme, was prescribed for each training session and was calculated using normative training load responses from performing on-field hockey drills. Magnitude based inferences focusing on the effect size (ES) and a Pearson Correlation Coefficient (r) were utilized to examine the degree of difference and the strength of correlation between the prescribed and experienced training loads. A significant correlation was observed between the experienced and prescribed training loads over the five-week mesocycle [r = 0.92, 90% CL (0.84:0.96)]. The percentage difference and the effect size between the achieved and prescribed training loads were as follows, Week1 demonstrated a 2.0% difference [ES = 0.10, 90% CL (-0.22:0.41)], Week 2 a -5.4% difference [ES = -0.41, 90% CL (-0.75:-0.07)], Week3 a -1.5% difference [ES = -0.09, 90% CL (-0.37:0.20)], Week4 a 7.1% difference [ES = 0.46, 90% CL (0.14:0.78)] and Week5 a 3.5% difference [ES = 0.18, 90% CL (-0.17:0.53)]. This investigation demonstrates the efficacy for coaches to prospectively design on-field training sessions utilizing normative training load data to enhance the congruence between the prescribed and experienced training loads over a periodized mesocycle.
Moran, Jason; Sandercock, Gavin R H; Ramírez-Campillo, Rodrigo; Todd, Oliver; Collison, Jay; Parry, Dave A
The purpose of this intervention study was to investigate if a low-dose of plyometric training (PT) could improve sprint and jump performance in groups of different maturity status. Male youth field hockey players were divided into Pre-PHV (from -1 to -1.9 from PHV; Experimental: n = 9; Control = 12) and Mid-PHV (0 to +0.9 from PHV; Experimental: n = 8; Control = 9) groups. Participants in the experimental groups completed 60 foot contacts, twice-weekly for 6 weeks. PT exerted a positive effect (effect size: 0.4 [-0.4-1.2]) on 10 m sprint time in the experimental Mid-PHV group but this was less pronounced in the Pre-PHV group (0.1 [-0.6-0.9]). Sprint time over 30 m (Mid-PHV: 0.1 [-0.8-0.9]; Pre-PHV: 0.1 [-0.7-0.9]) and CMJ (Mid-PHV: 0.1 [-0.8-0.9]; Pre-PHV: 0.0 [-0.7-0.8]) was maintained across both experimental groups. Conversely, the control groups showed decreased performance in most tests at follow up. Between-group analysis showed positive effect sizes across all performance tests in the Mid-PHV group, contrasting with all negative effect sizes in the Pre-PHV group. These results indicate that more mature hockey players may benefit to a greater extent than less mature hockey players from a low-dose PT stimulus. Sixty foot contacts, twice per week, seems effective in improving short sprint performance in Mid-PHV hockey players.
Kujala, U M; Taimela, S; Antti-Poika, I.; Orava, S; Tuominen, R; Myllynen, P. (Päivi)
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...
Michael D Cusimano
Full Text Available The frequency and potential long-term effects of sport-related traumatic brain injuries (TBI make it a major public health concern. The culture within contact sports, such as ice hockey, encourages aggression that puts youth at risk of TBI such as concussion. Newspaper reports play an important role in conveying and shaping the culture around health-related behaviors. We qualitatively studied reports about sport-related TBI in four major North American newspapers over the last quarter-century. We used the grounded-theory approach to identify major themes and then did a content analysis to compare the frequency of key themes between 1998-2000 and 2009-2011. The major themes were: perceptions of brain injury, aggression, equipment, rules and regulations, and youth hockey. Across the full study period, newspaper articles from Canada and America portrayed violence and aggression that leads to TBI both as integral to hockey and as an unavoidable risk associated with playing the game. They also condemned violence in ice hockey, criticized the administrative response to TBI, and recognized the significance of TBI. In Canada, aggression was reported more often recently and there was a distinctive shift in portraying protective equipment as a solution to TBI in earlier years to a potential contributing factor to TBI later in the study period. American newspapers gave a greater attention to 'perception of risks' and the role of protective equipment, and discussed TBI in a broader context in the recent time period. Newspapers from both countries showed similar recent trends in regards to a need for rule changes to curb youth sport-related TBI. This study provides a rich description of the reporting around TBI in contact sport. Understanding this reporting is important for evaluating whether the dangers of sport-related TBI are being appropriately communicated by the media.
Cusimano, Michael D; Sharma, Bhanu; Lawrence, David W; Ilie, Gabriela; Silverberg, Sarah; Jones, Rochelle
The frequency and potential long-term effects of sport-related traumatic brain injuries (TBI) make it a major public health concern. The culture within contact sports, such as ice hockey, encourages aggression that puts youth at risk of TBI such as concussion. Newspaper reports play an important role in conveying and shaping the culture around health-related behaviors. We qualitatively studied reports about sport-related TBI in four major North American newspapers over the last quarter-century. We used the grounded-theory approach to identify major themes and then did a content analysis to compare the frequency of key themes between 1998-2000 and 2009-2011. The major themes were: perceptions of brain injury, aggression, equipment, rules and regulations, and youth hockey. Across the full study period, newspaper articles from Canada and America portrayed violence and aggression that leads to TBI both as integral to hockey and as an unavoidable risk associated with playing the game. They also condemned violence in ice hockey, criticized the administrative response to TBI, and recognized the significance of TBI. In Canada, aggression was reported more often recently and there was a distinctive shift in portraying protective equipment as a solution to TBI in earlier years to a potential contributing factor to TBI later in the study period. American newspapers gave a greater attention to 'perception of risks' and the role of protective equipment, and discussed TBI in a broader context in the recent time period. Newspapers from both countries showed similar recent trends in regards to a need for rule changes to curb youth sport-related TBI. This study provides a rich description of the reporting around TBI in contact sport. Understanding this reporting is important for evaluating whether the dangers of sport-related TBI are being appropriately communicated by the media.
Jeff R. Leiter
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
Cusimano, Michael D.; Sharma, Bhanu; Lawrence, David W.; Ilie, Gabriela; Silverberg, Sarah; Jones, Rochelle
The frequency and potential long-term effects of sport-related traumatic brain injuries (TBI) make it a major public health concern. The culture within contact sports, such as ice hockey, encourages aggression that puts youth at risk of TBI such as concussion. Newspaper reports play an important role in conveying and shaping the culture around health-related behaviors. We qualitatively studied reports about sport-related TBI in four major North American newspapers over the last quarter-century. We used the grounded-theory approach to identify major themes and then did a content analysis to compare the frequency of key themes between 1998–2000 and 2009–2011. The major themes were: perceptions of brain injury, aggression, equipment, rules and regulations, and youth hockey. Across the full study period, newspaper articles from Canada and America portrayed violence and aggression that leads to TBI both as integral to hockey and as an unavoidable risk associated with playing the game. They also condemned violence in ice hockey, criticized the administrative response to TBI, and recognized the significance of TBI. In Canada, aggression was reported more often recently and there was a distinctive shift in portraying protective equipment as a solution to TBI in earlier years to a potential contributing factor to TBI later in the study period. American newspapers gave a greater attention to ‘perception of risks’ and the role of protective equipment, and discussed TBI in a broader context in the recent time period. Newspapers from both countries showed similar recent trends in regards to a need for rule changes to curb youth sport-related TBI. This study provides a rich description of the reporting around TBI in contact sport. Understanding this reporting is important for evaluating whether the dangers of sport-related TBI are being appropriately communicated by the media. PMID:23613957
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; Menon, Ravi S.
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 ...
Full Text Available The ability to efficiently utilize metabolic energy to produce work is a key factor for endurance performance. The present study investigated the effects of incline, performance level and gender on the gross mechanical efficiency during roller ski skating. Thirty-one male and nineteen female elite cross-country skiers performed a 5-min submaximal session at approximately 75% of VO2peak on a 5% inclined treadmill using the G3 skating technique. Thereafter, a 5-min session on a 12% incline using the G2 skating technique was performed at a similar work rate. Gross efficiency was calculated as the external work rate against rolling friction and gravity divided by the metabolic rate using gas exchange. Performance level was determined by the amount of skating FIS points (the Federation of International Skiing approved scoring system for ski racing where fewer points indicate a higher performance level. Strong significant correlations between work rate and metabolic rate within both inclines and gender were revealed (r=-0.89-0.98 and P
The objectives of this study were to investigate the nutritional value of skate meal (SM) and black cod viscera meal (BCVM) from Alaska and to ascertain their suitability as replacements for commercial pollock fishmeal in diets for Pacific threadfin (Polydactylus sexfilis). Test diets were made by r...
School Kids Access to Treats to Eat (SKATE) was a fruit and vegetable snack feeding study that assessed food recognition, food experience, and willingness to try specific fruits and vegetables of 186 elementary school children in grades 4-6 at high risk for obesity. This rural school had a 100% free...
Kelley, Catherine A; Decker, Sarah E; Silva, Patricio; Forrest, John N
Since the discovery of the rectal gland of the dogfish shark 50 years ago, experiments with this tissue have greatly aided our understanding of secondary active chloride secretion and the secretagogues responsible for this function. In contrast, very little is known about the rectal gland of skates. In the present experiments, we performed the first studies in the perfused rectal gland of the little skate (Leucoraja erinacea), an organ weighing less than one-tenth of the shark rectal gland. Our results indicate that the skate gland can be studied by modified perfusion techniques and in primary culture monolayers, and that secretion is blocked by the inhibitors of membrane proteins required for secondary active chloride secretion. Our major finding is that three G protein-coupled receptor agonists, the incretin gastric inhibitory polypeptide (GIP), also known as glucose-dependent insulinotropic peptide, as well as glucagon and serotonin, are unexpected potent chloride secretagogues in the skate but not the shark. Glucagon stimulated chloride secretion to a mean value of 1,661 ± 587 μeq·h(-1)·g(-1) and serotonin stimulated to 2,893 ± 699 μeq·h(-1)·g(-1). GIP stimulated chloride secretion to 3,733 ± 679 μeq·h(-1)·g(-1) and significantly increased tissue cAMP content compared with basal conditions. This is the first report of GIP functioning as a chloride secretagogue in any species or tissue.
Outevsky, David; Martin, Blake Cw
Dancesport, the competitive branch of ballroom dancing, places high physiological and psychological demands on its practitioners, but pedagogical resources in these areas for this dance form are limited. Dancesport competitors could benefit from strategies used in other aesthetic sports. In this review, we identify conditioning methodologies from gymnastics, figure skating, and contemporary, modern, and ballet dance forms that could have relevance and suitability for dancesport training, and propose several strategies for inclusion in the current dancesport curriculum. We reviewed articles derived from Google Scholar, PubMed, ScienceDirect, Taylor & Francis Online, and Web of Science search engines and databases, with publication dates from 1979 to 2013. The keywords included MeSH terms: dancing, gymnastics, physiology, energy metabolism, physical endurance, and range of motion. Out of 47 papers examined, 41 papers met the inclusion criteria (validity of scientific methods, topic relevance, transferability to dancesport, publication date). Quality and validity of the data were assessed by examining the methodologies in each study and comparing studies on similar populations as well as across time using the PRISMA 2009 checklist and flowchart. The relevant research suggests that macro-cycle periodization planning, aerobic and anaerobic conditioning, range of motion and muscular endurance training, and performance psychology methods have potential for adaptation for dancesport training. Dancesport coaches may help their students fulfill their ambitions as competitive athletes and dance artists by adapting the relevant performance enhancement strategies from gymnastics, figure skating, and concert dance forms presented in this paper.
Hwang, In Kwan; Lee, Hae Young; Kim, Min-Hee; Jo, Hyun-Su; Choi, Dong-Ho; Kang, Pil-Won; Lee, Yang-Han; Cho, Nam-Soo; Park, Ki-Won; Chae, Ho Zoon
The mottled skate, Beringraja pulchra is one of the commercially important fishes in the market today. However, B. pulchra identification methods have not been well developed. The current study reports a novel real-time PCR method based on TaqMan technology developed for the genetic identification of B. pulchra. The mitochondrial cytochrome oxidase subunit 1 (COI) nucleotide sequences of 29 B. pulchra, 157 skates and rays reported in GenBank DNA database were comparatively analyzed and the COI sequences specific to B. pulchra was identified. Based on this information, a system of specific primers and Minor Groove Binding (MGB) TaqMan probe were designed. The assay successfully discriminated in 29 specimens of B. pulchra and 27 commercial samples with unknown species identity. For B. pulchra DNA, an average Threshold Cycle (Ct) value of 19.1±0.1 was obtained. Among 27 commercial samples, two samples showed average Ct values 19.1±0.0 and 26.7±0.1, respectively and were confirmed to be B. pulchra based on sequencing. The other samples tested showed undetectable or extremely weak signals for the target fragment, which was also consistent with the sequencing results. These results reveal that the method developed is a rapid and efficient tool to identify B. pulchra and might prevent fraud or mislabeling during the distribution of B. pulchra products. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Di Santo, Valentina; Blevins, Erin L; Lauder, George V
Most batoids have a unique swimming mode in which thrust is generated by either oscillating or undulating expanded pectoral fins that form a disc. Only one previous study of the freshwater stingray has quantified three-dimensional motions of the wing, and no comparable data are available for marine batoid species that may differ considerably in their mode of locomotion. Here, we investigate three-dimensional kinematics of the pectoral wing of the little skate, Leucoraja erinacea , swimming steadily at two speeds [1 and 2 body lengths (BL) s -1 ]. We measured the motion of nine points in three dimensions during wing oscillation and determined that there are significant differences in movement amplitude among wing locations, as well as significant differences as speed increases in body angle, wing beat frequency and speed of the traveling wave on the wing. In addition, we analyzed differences in wing curvature with swimming speed. At 1 BL s -1 , the pectoral wing is convex in shape during the downstroke along the medio-lateral fin midline, but at 2 BL s -1 the pectoral fin at this location cups into the flow, indicating active curvature control and fin stiffening. Wing kinematics of the little skate differed considerably from previous work on the freshwater stingray, which does not show active cupping of the whole fin on the downstroke. © 2017. Published by The Company of Biologists Ltd.
Aschliman, Neil C; Nishida, Mutsumi; Miya, Masaki; Inoue, Jun G; Rosana, Kerri M; Naylor, Gavin J P
Skates, rays and allies (Batoidea) comprise more than half of the species diversity and much of the morphological disparity among chondrichthyan fishes, the sister group to all other jawed vertebrates. While batoids are morphologically well characterized and have an excellent fossil record, there is currently no consensus on the interrelationships of family-level taxa. Here we construct a resolved, robust and time-calibrated batoid phylogeny using mitochondrial genomes, nuclear genes, and fossils, sampling densely across taxa. Data partitioning schemes, biases in the sequence data, and the relative informativeness of each fossil are explored. The molecular phylogeny is largely congruent with morphology crownward in the tree, but the branching orders of major batoid groups are mostly novel. Body plan convergence appears to be widespread in batoids. A depressed, rounded pectoral disk supported to the snout tip by fin radials, common to skates and stingrays, is indicated to have been derived independently by each group, while the long, spiny rostrum of sawfishes similarly appears to be convergent with that of sawsharks, which are not batoids. The major extant batoid lineages are inferred to have arisen relatively rapidly from the Late Triassic into the Jurassic, with long stems followed by subsequent radiations in each group around the Cretaceous/Tertiary boundary. The fossil record indicates that batoids were affected with disproportionate severity by the end-Cretaceous extinction event. Copyright Â© 2011 Elsevier Inc. All rights reserved.
Ferrando, Sara; Bottaro, Massimiliano; Pedemonte, Federico; De Lorenzo, Simone; Gallus, Lorenzo; Tagliafierro, Grazia
Crypt neurons are olfactory receptor cells located in the olfactory epithelium of fishes. They exhibit a peculiar and well-recognizable morphology, although their odorant specificity is still unknown. Data on their appearance during development are few and far between. This study set out to identify the time at which crypt neurons appeared in the skate, Raja clavata, using histological and immunohistochemical methods. For this purpose, embryos and juveniles at different stages of development, from 13 weeks after laying (11 weeks before hatching) to 24 weeks after hatching, were examined. The crypt neurons were identified on a morphological basis. An anti-alpha-tubulin antibody and two lectins (wheat germ agglutinin and peanut agglutinin) were used to highlight morphological details. The olfactory marker protein was detected by immunohistochemistry, because this protein is a marker of neuronal maturity in vertebrates. The crypt neurons could be detected by their morphology at 15 weeks after laying and became strongly olfactory marker protein immunoreactive 22 weeks after laying. Although involvement of crypt neurons in reproductive behavior has been inferred in various studies on bony fishes, their early presence in skate embryos and juveniles may suggest that they are not exclusively involved in sexual behavior. (c) 2007 Wiley-Liss, Inc.
Song, Yeong Ok; Kim, Mijeong; Woo, Minji; Baek, Jang-Mi; Kang, Keon-Hee; Kim, Sang-Ho; Roh, Seong-Soo; Park, Chan Hum; Jeong, Kap-Seop; Noh, Jeong-Sook
The protective effects of a chondroitin sulfate-rich extract (CSE) from skate cartilage against lipopolysaccharide (LPS)-induced hepatic damage were investigated, and its mechanism of action was compared with that of chondroitin sulfate (CS) from shark cartilage. ICR mice were orally administrated 200 mg/kg body weight (BW) of CS or 400 mg/kg BW of CSE for 3 consecutive days, followed by a one-time intraperitoneal injection of LPS (20 mg/kg BW). The experimental groups were vehicle treatment without LPS injection (NC group), vehicle treatment with LPS injection (LPS group), CS pretreatment with LPS injection (CS group), and CSE pretreatment with LPS injection (CSE group). Hepatic antioxidant enzyme expression levels in the CS and CSE groups were increased relative to those in the LPS group. In LPS-insulted hepatic tissue, inflammatory factors were augmented relative to those in the NC group, but were significantly suppressed by pretreatment with CS or CSE. Moreover, CS and CSE alleviated the LPS-induced apoptotic factors and mitogen-activated protein kinase (MAPK). In addition, CS and CSE effectively decreased the serum lipid concentrations and downregulated hepatic sterol regulatory element-binding proteins expression. In conclusion, the skate CSE could protect against LPS-induced hepatic dyslipidemia, oxidative stress, inflammation, and apoptosis, probably through the regulation of MAPK signaling. PMID:28617322
Motta, N S; Della-Fina, N; Souza, C C A; Rodrigues, E S; Amorim, A F
Catches and exports of skate Rioraja agassizii place this species as "vulnerable to extinction" on the IUCN Red List; therefore, biological and ecological knowledge becomes an important instrument for its conservation control. This study described and quantified the diet composition of R. agassizii by means of stomach analysis contents in the periods 2005-2006 and 2012-2013. We analyzed and quantified stomach contents in terms of abundance (%N), weight (%M), frequency of occurrence (% FO), and index of relative importance (IRI). The results showed differences in the food rates between the periods. However, the groups of food items were the same: Teleostei fish, decapods, and mollusks. In 2005-2006, the diet consisted mainly of shrimp, however, in 2012-2013 it consisted of fish, followed by decapods, especially shrimps. The differences in diets may be attributed to shrimp abundance, which do not characterize a change in the eating habits in 2012-2013, because, in addition to fish, shrimps were also important food sources. The presence of a certain prey is more related to its availability rather than the feeding preference of skate. The amount of ingested items is associated to biological and environmental factors, so that further studies relating diet with capture area, seasonality, depth, and other factors should be conducted.
N. S. Motta
Full Text Available Abstract Catches and exports of skate Rioraja agassizii place this species as “vulnerable to extinction” on the IUCN Red List; therefore, biological and ecological knowledge becomes an important instrument for its conservation control. This study described and quantified the diet composition of R. agassizii by means of stomach analysis contents in the periods 2005-2006 and 2012-2013. We analyzed and quantified stomach contents in terms of abundance (%N, weight (%M, frequency of occurrence (% FO, and index of relative importance (IRI. The results showed differences in the food rates between the periods. However, the groups of food items were the same: Teleostei fish, decapods, and mollusks. In 2005-2006, the diet consisted mainly of shrimp, however, in 2012-2013 it consisted of fish, followed by decapods, especially shrimps. The differences in diets may be attributed to shrimp abundance, which do not characterize a change in the eating habits in 2012-2013, because, in addition to fish, shrimps were also important food sources. The presence of a certain prey is more related to its availability rather than the feeding preference of skate. The amount of ingested items is associated to biological and environmental factors, so that further studies relating diet with capture area, seasonality, depth, and other factors should be conducted.
Piucco, Tatiane; Bini, Rodrigo; Sakaguchi, Masanori; Diefenthaeler, Fernando; Stefanyshyn, Darren
This study investigated how the combination of workload and fatigue affected the frequency components of muscle activation and possible recruitment priority of motor units during skating to exhaustion. Ten male competitive speed skaters performed an incremental maximal test on a slide board. Activation of six muscles from the right leg was recorded throughout the test. A time-frequency analysis was performed to compute overall, high, and low frequency bands from the whole signal at 10, 40, 70, and 90% of total test time. Overall activation increased for all muscles throughout the test (p 0.80). There was an increase in low frequency (90 vs. 10%, p = 0.035, ES = 1.06) and a decrease in high frequency (90 vs. 10%, p = 0.009, ES = 1.38, and 90 vs. 40%, p = 0.025, ES = 1.12) components of gluteus maximus. Strong correlations were found between the maximal cadence and vastus lateralis, gluteus maximus and gluteus medius activation at the end of the test. In conclusion, the incremental skating test lead to an increase in activation of lower limb muscles, but only gluteus maximus was sensitive to changes in frequency components, probably caused by a pronounced fatigue.
Sulak, Kenneth J.; MacWhirter, P. D.; Luke, K.E.; Norem, A.D.; Miller, J.M.; Cooper, J.A.; Harris, L.E.
Ecosystem-based management requires sound information on the distribution and abundance of species both common and rare. Therefore, the accurate identification for all marine species has assumed a much greater importance. The identification of many skate species is difficult as several are easily confused and has been found to be problematic in both survey data and fisheries data collection. Identification guides, in combination with training and periodic validation of taxonomic information, improve our accuracy in monitoring data required for ecosystem-based management and monitoring of populations. This guide offers a comparative synthesis of skate species known to occur in Atlantic Canada and adjacent regions. The taxonomic nomenclature and descriptions of key morphological features are based on the most up-to-date understanding of diversity among these species. Although this information will aid the user in accurate identification, some features vary geographically (such as colour) and others with life stage (most notably the proportion of tail length to body length; the presence of spines either sharper in juveniles or in some cases not yet present; and also increases in the number of tooth rows as species grow into maturity). Additional information on juvenile features are needed to facilitate problematic identifications (e.g. L. erinacea vs. L. ocellata). Information on size at maturity is still required for many of these species throughout their geographic distribution.
Full Text Available This study aims to develop and validate an automated system for identifying skating-style cross-country subtechniques using inertial sensors. In the first experiment, the performance of a male cross-country skier was used to develop an automated identification system. In the second, eight male and seven female college cross-country skiers participated to validate the developed identification system. Each subject wore inertial sensors on both wrists and both roller skis, and a small video camera on a backpack. All subjects skied through a 3450 m roller ski course using a skating style at their maximum speed. The adopted subtechniques were identified by the automated method based on the data obtained from the sensors, as well as by visual observations from a video recording of the same ski run. The system correctly identified 6418 subtechniques from a total of 6768 cycles, which indicates an accuracy of 94.8%. The precisions of the automatic system for identifying the V1R, V1L, V2R, V2L, V2AR, and V2AL subtechniques were 87.6%, 87.0%, 97.5%, 97.8%, 92.1%, and 92.0%, respectively. Most incorrect identification cases occurred during a subtechnique identification that included a transition and turn event. Identification accuracy can be improved by separately identifying transition and turn events. This system could be used to evaluate each skier’s subtechniques in course conditions.
Sakurai, Yoshihisa; Fujita, Zenya; Ishige, Yusuke
This study aims to develop and validate an automated system for identifying skating-style cross-country subtechniques using inertial sensors. In the first experiment, the performance of a male cross-country skier was used to develop an automated identification system. In the second, eight male and seven female college cross-country skiers participated to validate the developed identification system. Each subject wore inertial sensors on both wrists and both roller skis, and a small video camera on a backpack. All subjects skied through a 3450 m roller ski course using a skating style at their maximum speed. The adopted subtechniques were identified by the automated method based on the data obtained from the sensors, as well as by visual observations from a video recording of the same ski run. The system correctly identified 6418 subtechniques from a total of 6768 cycles, which indicates an accuracy of 94.8%. The precisions of the automatic system for identifying the V1R, V1L, V2R, V2L, V2AR, and V2AL subtechniques were 87.6%, 87.0%, 97.5%, 97.8%, 92.1%, and 92.0%, respectively. Most incorrect identification cases occurred during a subtechnique identification that included a transition and turn event. Identification accuracy can be improved by separately identifying transition and turn events. This system could be used to evaluate each skier's subtechniques in course conditions.
Baker, Joseph; Janning, Christina; Wong, Harmonie; Cobley, Stephen; Schorer, Jörg
In many sports, policy-makers and administrators employ annual cohorts to reduce differences between athletes during childhood and youth. Although well-intended, unintended relative age effects (RAEs) usually occur. RAEs refer to the specific selection, participation and attainment disadvantages associated with participants' birthdates relative to an arbitrary 'cutoff' date used to group participants within annual age groups. To date, we have little understanding of RAEs in individual sports. In this article, Study 1 considered the presence of RAEs in 1474 ski jumping, 7501 cross-country skiing, 15,565 alpine skiing, 4179 snowboarders and 713 Nordic combined athletes. Chi-square analyses revealed significant RAEs for most of these contexts across sexes. In Study 2, RAEs in the aesthetic sports of figure skating (n=502) and female gymnastics (n=612) were considered. There was no effect for the figure skaters and an atypical effect for the gymnasts. The significant effects across most ski sports coupled with the null effects in figure skating and atypical effect in gymnastics suggest that sport-specific contextual factors are important elements in understanding the mechanisms of RAEs, although further work is necessary to validate these findings.
Dillon, J P
Since the opening of a temporary ice-rink in our hospital\\'s catchment area, we have observed an increase in patients requiring in-patient treatment for orthopaedic intervention. The authors performed a prospective analysis of all patients admitted to our unit over a one-month period. Epidemiological data, wearing of protective gear and skater experience were collected. Fracture type, treatment required, average length of hospital stay and number of days missed from work was also recorded. Ice-skating injuries accounted for 7.7% of our total admissions over the study period. There was a significant variation noted in the types of fracture sustained ranging from comminuted fractures of the radial head to spiral fractures of the tibia. The average length of hospital stay was 2.6 days and average time missed from work was 6.1 weeks. This paper highlights the potential serious injuries that can occur in ice-skating and their impact on admissions to our orthopaedic unit.
Bussey, Melanie D; Kennedy, James E; Kennedy, Gavin
To examine the effect of prolonged standing on gluteus medius coactivation and to observe whether the changes in gluteus medius coactivation over time were related to the development of low back pain in elite female field hockey players. Prospective cohort design. Participants were 39 elite female field hockey players (14 with a history of low back pain). Before the prolonged stand, maximal hip abduction strength, side bridge hold endurance and hip abduction range of motion were measured bilaterally. Surface electromyography was collected from the gluteus medius for coactivation analysis during a prolonged stand for 70 min. Low back pain was rated every 10 min on a visual analogue scale. Fourteen of 39 participants developed low back pain. The Time effect was significant for gluteus medius coactivation response (p = 0.003) and visual analogue scale score (p pain had higher coactivation for the majority of the stand task. While female field hockey players have high agonist-antagonist coactivation patterns during prolonged standing, stand task is a useful tool to predict low back pain occurrence in players with and without history of pain. Copyright © 2015 Elsevier Ltd. All rights reserved.
Kujala, U. M.; Taimela, S.; Antti-Poika, I.; Orava, S.; Tuominen, R.; Myllynen, P.
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
Parenteau-G, Elizabeth; Gaudreault, Nathaly; Chambers, Stéphane; Boisvert, Caroline; Grenier, Alexandre; Gagné, Geneviève; Balg, Frédéric
To determine inter-rater and intra-rater reliability of the Functional Movement Screen (FMS) test among young elite hockey players. Reliability study. Inter-rater reliability was evaluated by two raters in the field. All performances were videotaped. Two other raters evaluated the videos once and then again 6 weeks later to determine intra-rater reliability. A weighted kappa statistic was used to analyze intra-rater and inter-rater reliability of each FMS sub-test, while an intra-class correlation coefficient (ICC) was calculated for the total score. Twenty-eight male hockey players aged 13-16. FMS total and sub-tests scores. The video raters demonstrated excellent intra-rater reliability for the total score, with an ICC of 0.96 (95% CI; 0.92-0.98) and 0.96 (95% CI; 0.91-0.98). The field raters achieved excellent inter-rater reliability for the total score, with an ICC of 0.96 (95% CI; 0.92-0.98). Sub-test analysis showed good agreement among all four raters for five of the seven main sub-tests. FMS is a reliable test for young elite hockey players. Further research should be done to assess the predictive validity of the FMS test within this population so that physiotherapists may eventually use it as an injury prevention tool. Copyright © 2013 Elsevier Ltd. All rights reserved.
Full Text Available Background: Repeated sprint ability tests are today widely used to evaluate the performance capability in team sports. Objective: The aim of this study was to determine the reliability of a specific ice hockey test, which indicates the agility and repeated-sprint ability of the players. Methods: Twenty four highly trained junior ice hockey players (age = 17.68 ± 1.52 years; BMI = 23.8 ± 1.92 kg . m-2 participated in the study. Each participant was assessed for specific on-ice repeated-sprint ability test 12 × 54 m with 30 s rest. Intraclass correlation coefficient (association between two repeated measurements and coefficient of variation were calculated to assess the reliability of the test. Results: All intraclass correlation coefficients were .78 for sprint decrement and .98 for total time and the best time, the coefficient of variation was 1.52% for best sprint time, 1.31% for total time and 19.3% for sprint decrement variable. Conclusions: The results suggest the high reliability of the ice hockey agility test expressed by the best sprint time and repeated-sprint ability by the total time and less reliability of sprint decrement.
Bruner, Mark W; Macdonald, Dany J; Pickett, William; Côté, Jean
The present study investigated birthdate (known as the Relative Age Effect; RAE) and birthplace as determinants of expertise in an international sample of elite ice hockey players. The sample included 566 World Junior (WJR) ice hockey players from four countries (Canada, n = 153; USA, n = 136; Sweden, n = 140; Finland, n = 137). Participants competed in the International Ice Hockey Federation World U20 Championship between 2001 and 2009. A series of Poisson regression models were conducted to examine the consistency of direct then interactive relationships between both birthdate and birthplace and WJR membership across the four countries (Canada, USA, Sweden, and Finland). Findings revealed a consistent RAE across the four countries for World Junior participation from 2000 to 2009. WJR players from the four countries were also less likely to be from major cities. In addition, there was no evidence in any of the four countries of an interaction between RAE and birthplace. Future research should explore the contextual and cultural factors that influence elite athlete development in smaller towns, cities and communities.
Smith, Aynsley M; Stuart, Michael J; Roberts, William O; Dodick, David W; Finnoff, Jonathan T; Jorgensen, Janelle K; Krause, David A
This review provides an update on sport-related concussion (SRC) in ice hockey and makes a case for changes in clinical concussion evaluation. Standard practice should require that concussions be objectively diagnosed and provide quantitative measures of the concussion injury that will serve as a platform for future evidence-based treatment. The literature was surveyed to address several concussion-related topics: research in ice hockey-related head trauma, current subjective diagnosis, promising components of an objective diagnosis, and current and potential treatments. Sport-related head trauma has marked physiologic, pathologic, and psychological consequences for athletes. Although animal models have been used to simulate head trauma for pharmacologic testing, the current diagnosis and subsequent treatment in athletes still rely on an athlete's motivation to report or deny symptoms. Bias-free, objective diagnostic measures are needed to guide quantification of concussion severity and assessment of treatment effects. Most of the knowledge and management guidelines of concussion in ice hockey are generalizable to other contact sports. There is a need for an objective diagnosis of SRC that will quantify severity, establish a prognosis, and provide effective evidence-based treatment. Potential methods to improve concussion diagnosis by health care providers include a standardized concussion survey, the King-Devick test, a quantified electroencephalogram, and blood analysis for brain cell-specific biomarkers.
Andrew Mark Griffiths
Full Text Available Skates are widely consumed across the globe, but many large species are subject to considerable concern regarding their conservation and management. Within Europe such issues have recently driven policy changes so that, for the first time, reports of skate landings now have to be made under species-specific names. Total allowable catches have also been established for many groups, which have been set to zero for a number of the most vulnerable species (e.g., Dipturus batis, Raja undulata and Rostoraja alba. Whilst accurate species identification has become an important issue for landings, the sale of skates is still usually made under a blanket term of “skate” or “ray”. The matter of identifying species of skate is further complicated by their morphologically conservative nature and the fact that they are commercially valued for their wings. Thus, before sale their bodies are usually discarded (i.e., “winged” and often skinned, making morphological identification impossible. For the first time, DNA barcoding (of the mitochondrial COI gene was applied to samples of skate wings from retail outlets across the British Isles, providing insight into which species are sold for consumption. A total of 98 wing samples were analysed, revealing that six species were sold; blonde ray (Raja brachyura, spotted ray (Raja montagui, thornback ray (Raja clavata, cuckoo ray (Leucoraja naevus small-eyed ray (Raja microocellata and shagreen ray (Leucoraja fullonica. Statistical testing demonstrated that there were significant differences in the species sold in the distinct retail groups which suggests complex drivers behind the patterns of sale in skates. The results also indicate that endangered species are not commonly being passed on to consumers. In addition, the practice of selling skate wings under ambiguous labels is highlighted as it makes it extremely difficult for consumers to exercise a right to avoid species of conservation concern
Egan, Aaron; Fox, Jennifer; Greenfield, Adam; Mariani, Stefano
Skates are widely consumed across the globe, but many large species are subject to considerable concern regarding their conservation and management. Within Europe such issues have recently driven policy changes so that, for the first time, reports of skate landings now have to be made under species-specific names. Total allowable catches have also been established for many groups, which have been set to zero for a number of the most vulnerable species (e.g., Dipturus batis, Raja undulata and Rostoraja alba). Whilst accurate species identification has become an important issue for landings, the sale of skates is still usually made under a blanket term of “skate” or “ray”. The matter of identifying species of skate is further complicated by their morphologically conservative nature and the fact that they are commercially valued for their wings. Thus, before sale their bodies are usually discarded (i.e., “winged”) and often skinned, making morphological identification impossible. For the first time, DNA barcoding (of the mitochondrial COI gene) was applied to samples of skate wings from retail outlets across the British Isles, providing insight into which species are sold for consumption. A total of 98 wing samples were analysed, revealing that six species were sold; blonde ray (Raja brachyura), spotted ray (Raja montagui), thornback ray (Raja clavata), cuckoo ray (Leucoraja naevus) small-eyed ray (Raja microocellata) and shagreen ray (Leucoraja fullonica). Statistical testing demonstrated that there were significant differences in the species sold in the distinct retail groups which suggests complex drivers behind the patterns of sale in skates. The results also indicate that endangered species are not commonly being passed on to consumers. In addition, the practice of selling skate wings under ambiguous labels is highlighted as it makes it extremely difficult for consumers to exercise a right to avoid species of conservation concern. Interestingly, a
Gouttebarge, Vincent; Kerkhoffs, Gino M M J
Scientific knowledge about symptoms of common mental disorders in professional ice hockey is lacking. Consequently, the primary aims of the study were to (i) determine the prevalence, comorbidity and 6-month incidence of symptoms of common mental disorders (distress, anxiety/depression, sleep disturbance, adverse alcohol use, eating disorders) among current and retired professional ice hockey players and (ii) evaluate their potential relation with potential stressors (severe musculoskeletal injuries, surgeries, recent life events, career dissatisfaction). A prospective cohort study with a 6-month follow-up period was conducted. Using validated questionnaires to assess symptoms of common mental disorders (thus not clinically diagnosed) as well as several stressors, an electronic questionnaire was set up and distributed by the national ice hockey players' unions from Denmark, Finland, Norway and Switzerland. Prevalence ranged from 8% for adverse alcohol use to 24% for anxiety/depression among current professional ice hockey players, and from 12% for distress to 29% for adverse alcohol among retired professional ice hockey players. Six-month incidence reached up to 22% for eating disorders among current players and 25% for sleep disturbance among retired players. Especially a higher number of surgeries, a higher number of recent life events and higher level of career dissatisfaction was related to symptoms of common mental disorders. Our findings indicate that adequate interventions should be developed to improve not only awareness and psychological resilience of both current and retired ice hockey players but also their performance and quality-of-life. An interdisciplinary approach should be applied in the medical care of ice hockey players by including psychologists/psychiatrists who can provide psychotherapeutic or clinical interventions.
Tuominen, Markku; Hänninen, Timo; Parkkari, Jari; Stuart, Michael J; Luoto, Teemu; Kannus, Pekka; Aubry, Mark
Concussions in sports are a growing concern. This study describes the incidence, injury characteristics and time trends of concussions in international ice hockey. All concussions in the International Ice Hockey Federation (IIHF) World Championships (WC) and Olympic Winter Games were analysed over 9 ice hockey seasons between 2006 and 2015 using a standardised injury reporting system and diagnoses made by the team physicians. A total of 3293 games were played (169 tournaments, 1212 teams, 26 130 players) comprising 142 244 athletic game exposures. The average injury rate (IR) for concussion was 1.1 per 1000 ice hockey player-games for all IIHF WC tournaments. The IR was the highest in the men's WC A-pool tournaments and Olympic Games (IR 1.6). However, the annual IR for concussion in the men's tournaments has been lower than that in the World Junior tournaments since 2012. When a concussion occurred with contact to a flexible board, the IR was 0.2 per 1000 player games. In contrast, the IR was 1.1, if the board and glass were traditional (for the latter, RR 6.44 (95% CI 1.50 to 27.61)). In the men's tournaments, the trend of concussions caused by illegal hits decreased over the study period. After the 4th Consensus Statement on Concussion in Sport was published (2013), none of the concussed players in the men's WC returned to play on the day of injury. The annual risk of concussion in the men's WC has decreased during the study period. This was most likely due to a reduction in illegal hits. The risk of concussion was significantly lower if games were played on rinks with flexible boards and glass. Rink modifications, improved education and strict rule enforcement should be considered by policymakers in international ice hockey. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
McKann, Robert; Coffee, Claude W.; Abrabian, Donald D.
The take-off stability characteristics of a Consolidated Vultee Aircraft Corporation Skate 7 seaplane were determined in the Langley tank no. 2. Trim limits of stability, trim tracks, and elevator limits of stability are presented.
McKann, Robert E.; Coffee, Claude W.; Arabian, Donald D.
A model of a Consolidated Vultee Aircraft Corporation Skate 7 sea-plane:was tested in Langley tank no= 2. Resistance data, 'spray photographs, and underwater photographs,are given in this report without discussion.
Effects of exposure to coplanar polychlorinated biphenyls (PCBs) and other dioxin-like chemicals on developing vertebrates involve many organ systems, including the skeletal and cardiovascular systems. Apex predators, including those from the class Chondrichthyes (sharks, skates,...
Lerebours, Frantz; Robertson, William; Neri, Brian; Schulz, Brian; Youm, Thomas; Limpisvasti, Orr
Femoroacetabular impingement (FAI) has been increasingly recognized as a cause of hip pain in athletes at all levels of competition, specifically ice hockey players. The purpose of this study was to define the prevalence of cam and pincer radiographic deformity in elite ice hockey players. The hypothesis was that elite hockey players will have a higher prevalence of radiographic hip abnormalities compared with the general population. Cross-sectional study; Level of evidence, 3. Anteroposterior and frog-leg lateral radiographs on 137 elite ice hockey players were prospectively obtained during the 2014-2015 preseason entrance examinations. Study participants included National Hockey League roster players as well as the respective farm team members. Demographic data were collected, including age, position, shooting side, and any history of hip pain or hip surgery. Patients with a history of hip surgery were excluded from the analysis. A single sports medicine fellowship-trained orthopaedic surgeon used standard radiographic measurements to assess for the radiographic presence of cam or pincer deformity. Radiographs with an alpha angle ≥55° on a frog-leg lateral view were defined as cam-positive. Each participant underwent a preseason physical examination with an assessment of hip range of motion and impingement testing. A total of 130 elite ice hockey players were included in the analysis; 180 (69.4%) hips met radiographic criteria for cam-type deformity. The prevalence in right and left hips was 89 (69.5%) and 91 (70.0%), respectively; 70 (60.8%) players demonstrated bilateral involvement. Hips with cam deformity had a mean alpha angle of 67.7° ± 8.3° on the right and 68.9° ± 9.0° on the left. Of the patients with alpha angles ≥55°, 5.6% (5/89) had a positive anterior impingement test of the right hip, while 11% (10/91) had positive anterior impingement test of the left. Players with radiologic cam deformity had a statistically significant deficit in
Wahyu Putri Vembriana Dewi
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.
Orr, James W.; Stevenson , Duane E.; Hoff, Gerald R.; Spies, Ingrid; McEachran, John D.
We provide morphological and molecular evidence to recognize a new species of skate from the North Pacific, Bathyraja panthera. We also resurrect the skate subgenus Arctoraja Ishiyama, confirming its monophyly and the validity of the subgenus. Arctoraja was previously recognized as a distinct subgenus of Breviraja and later synonymized with Bathyraja (family Rajidae). Although the nominal species of Arctoraja have all been considered synonyms of Bathyraja parmifera by various authors, on t...
Ehlinger, Sally; Katz, Jennifer L.
Reports a study that analyzed high school girls' experiences as they established ice hockey as a competitive girls' sport. Surveys of the social, psychological, and skill aspects of their experiences indicated high enthusiasm and determination levels, with 80% of them definitely planning to continue playing ice hockey. (SM)
Irigoitia, Manuel M; Cantatore, Delfina M P; Delpiani, Gabriela E; Incorvaia, Inés S; Lanfranchi, Ana L; Timi, Juan T
A new species of Merizocotyle Cerfontaine, 1894 (Monogenea: Monocotylidae) is described from the nasal tissues of three deep sea rajid skates: the southern thorny skate, Amblyraja doellojuradoi (Pozzi), broadnose skate, Bathyraja brachyurops (Fowler), and yellownose skate, Zearaja chilensis (Guichenot), collected off Buenos Aires Province, Argentina, southwest Atlantic Ocean. Two additional species of sympatric rajid, the white-dotted skate, Bathyraja albomaculata (Norman), and the Patagonian skate, Bathyraja macloviana (Norman), were also examined but no merizocotylines were found. The taxonomy of the Merizocotylinae is not widely accepted and, as a result, the status of Thaumatocotyle and Mycteronastes, and their proposed synonymy with Merizocotyle are currently under discussion. The new species differs from its congeners by having a unique haptoral structure, 6 peripheral loculi that are asymmetrically arranged (one much smaller, indistinctly located in the left or right side of the haptor). The presence of the new species in three sympatric species of Rajidae belonging to distinct genera and subfamilies, as well as its absence in sympatric congenerics indicates the lack of phylogenetic host specificity. Host ecology and geographical distribution appear to be more important than host phylogeny in determining the distribution of this parasite across potential hosts in the region. This constitutes the first record of Merizocotyle in the southwestern Atlantic Ocean.
Florentina Johanna Hettinga
Full Text Available Due to the technical nature of speed skating, that is affecting physiological mechanisms such as oxygenation and blood flow, this sport provides a unique setting allowing us to uncover novel mechanistic insights of the physiological response to exercise in elite middle-distance and endurance sports. The present study aimed to examine the influence of skating mode (short-track vs. long-track on muscle oxygenation, perceived fatigue, and recovery in elite speed skating. Muscle oxygenation of twelve talented short-track speed skaters was continuously monitored during a long-track (LT and a short-track (ST skating time-trials of maximal effort using near-infrared spectroscopy (NIRS on the m. vastus lateralis for both legs. Video captures were made of each testing session for further interpretation of the muscle oxygenation. To determine recovery, perceived exertion was measured two and four hours after each testing sessions. Repeated measures ANOVA’s were used for statistical analysis (p<.05. After a rapid desaturation in both legs directly after the start, an asymmetry in muscle oxygenation between both legs was found during LT (tissue saturation-index (TSI%-slope: left=0.053±0.032; right=0.023±0.020, p<.05 and ST speed skating (TSI%-slope: left=0.050±0,052, right=0.001 ±0.053, p<.05. Re-Resaturation of the right leg was relatively lower in ST compared to LT. For the left leg, no difference was found between skating modes in muscle oxygenation. Respectively, two (ST=5.8±2.0; LT=4.2±1.5 and four hours (ST=4.6±1.9; LT=3.1±1.6 after the time-trials, a higher rate of perceived exertion was found for ST. Based on our results, ST seems more physiologically demanding, and longer periods of recovery are needed after training compared to LT. Technical aspects unique to the exercise mode seem to impact on oxygenation, affecting processes related to the regulation of exercise intensity such as fatigue and recovery.
Full Text Available The possibilities of improving sportsmanship hockey on grass-based modeling-based approach. The aim is to study the dynamics of technical preparedness of highly qualified hockey players on grass under the influence of experimental summer system of development a training process. The experiment involved 21 athlete (average age - 23.7 years. Installed speaker technical training of highly qualified hockey players on grass during the annual macrocycle. The identified model parameters of technical preparedness of the players on each of the main stages of the annual training cycle. Reserves in terms of technical training are seen in increasing performance testing exercises on speed. It is recommended to eliminate the imbalance in the use of specific and nonspecific means.
Lemez, S; Baker, J; Horton, S; Wattie, N; Weir, P
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 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.
Full Text Available Purpose: analysis of technique of skiing skating style of leading sportsmen of the world. Material and Methods: research was conducted by means of analysis of video data and кинограмм of of skilled racing cross-country ski and biathlon of leading countries of the world. Results: the analysis of dynamic descriptions of technique of the same name ski motions educed the row of factors, from that sportsmen, what applied «Double Push» in the technique of skiing, increase speed of passing of short segments on 4-6%. Conclusions: implementation of «Double Push» can useful for racing cross-country ski and biathlon on competitions on a sprint, on rollers-ski and at implementation of short accelerations on distance, and also on a finish
Matta, M E
A total of 1357 specimens of Alaska skate Bathyraja parmifera were collected in the eastern Bering Sea by fisheries observers and during scientific groundfish surveys from 2003 to 2005. Male and female gonads were examined for maturity stage and seasonal reproductive timing. Based on seasonal reproductive data, including the occurrence of egg cases, ovum size, ovum number, shell-gland width and gonado-somatic index, this species appears to reproduce continually throughout the year. Potential effects of maternal size upon the size and number of mature oocytes were also investigated, with total length having a significant, although weak, influence on both. Morphology of a single intersexual individual encountered during the collection period is also described. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.
Last, Peter R; Alava, Moonyeen
A new long-snouted skate, Dipturus amphispinus sp. nov., is formally described based on material caught in the Sulu Sea and later acquired from fish markets of the central and southern Philippines. It differs from its congeners in the western North Pacific, apart from D. wuhanlingi (East and South China Seas), in having a variably-defined, parallel row of posterolaterally directed lumbar thorns, and well-developed scapular thorns on each side of the disc. However, the paired rows of lumbar thorns are better defined in Dipturus amphispinus sp. nov. than in D. wuhanlingi, and these species also differ in some aspects of their morphometrics, meristics and squamation. Dipturus amphispinus sp. nov. displays marked sexual dimorphism with adult males having a relatively broader mouth, much longer teeth, a relatively shorter snout, head and disc, a taller first dorsal fin, and a proportionally longer posterior pelvic-fin lobe and tail, than adult-sized females.
Luciano Hermes da Silva
Full Text Available Este artigo pretende problematizar a prática do skate de rua como objeto de reflexão no âmbito do ensino de Geografia. Objetiva demonstrar como os skatistas protagonizam a ressignificação da cidade através de usos originais do mobiliário urbano. Trata-se de reforçar o movimento que articula as práticas espaciais dos jovens aos conteúdos e temas tradicionais da Geografia. A partir da referência ao conceito de espaço público, busca-se demonstrar que o recurso às práticas cotidianas da juventude permite problematizar conflitos, relações identitárias e processos relacionados à produção social do espaço.
Hu, Fa-Yuan; Chi, Chang-Feng; Wang, Bin; Deng, Shang-Gui
In the current study, the preparation conditions of neutrase hydrolysate (SMH) from skate (Raja porosa) muscle protein were optimized using orthogonal L9(3)4 tests, and R values indicated that pH was the most important factor affecting HO· scavenging activity of SMH. Under the optimum conditions of pH 7.0, enzymolysis temperature 60 °C, enzyme/substrate ratio (E/S) 2%, and enzymolysis time 5 h, EC50 of SMH on HO· was 2.14 ± 0.17 mg/mL. Using ultrafiltration, gel filtration chromatography, and RP-HPLC, two novel antioxidant nonapeptides (SP-A and SP-B) were isolated from SMH and their amino acid sequences were found to be APPTAYAQS (SP-A) and NWDMEKIWD (SP-B) with calculated molecular masses of 904.98 Da and 1236.38 Da, respectively. Both showed strong antioxidant activities. SP-A and SP-B exhibited good scavenging activities on HO· (EC50 0.390 and 0.176 mg/mL), DPPH· (EC50 0.614 and 0.289 mg/mL), and O2-· (EC50 0.215 and 0.132 mg/mL) in a dose-dependent manner. SP-B was also effective against lipid peroxidation in the model system. The aromatic (2Trp), acidic (2Asp and Glu), and basic (Lys) amino acid residues within the sequences of SP-B might account for its pronounced antioxidant activity. The results of this study suggested that protein hydrolysate and peptides from skate muscle might be effective as food additives for retarding lipid peroxidation occurring in foodstuffs.
Full Text Available In the current study, the preparation conditions of neutrase hydrolysate (SMH from skate (Raja porosa muscle protein were optimized using orthogonal L9(34 tests, and R values indicated that pH was the most important factor affecting HO· scavenging activity of SMH. Under the optimum conditions of pH 7.0, enzymolysis temperature 60 °C, enzyme/substrate ratio (E/S 2%, and enzymolysis time 5 h, EC50 of SMH on HO· was 2.14 ± 0.17 mg/mL. Using ultrafiltration, gel filtration chromatography, and RP-HPLC, two novel antioxidant nonapeptides (SP-A and SP-B were isolated from SMH and their amino acid sequences were found to be APPTAYAQS (SP-A and NWDMEKIWD (SP-B with calculated molecular masses of 904.98 Da and 1236.38 Da, respectively. Both showed strong antioxidant activities. SP-A and SP-B exhibited good scavenging activities on HO· (EC50 0.390 and 0.176 mg/mL, DPPH· (EC50 0.614 and 0.289 mg/mL, and O2−· (EC50 0.215 and 0.132 mg/mL in a dose-dependent manner. SP-B was also effective against lipid peroxidation in the model system. The aromatic (2Trp, acidic (2Asp and Glu, and basic (Lys amino acid residues within the sequences of SP-B might account for its pronounced antioxidant activity. The results of this study suggested that protein hydrolysate and peptides from skate muscle might be effective as food additives for retarding lipid peroxidation occurring in foodstuffs.
Alessandra da Fonseca Viana
Full Text Available The stomach contents of the eyespot skate, Atlantoraja cyclophora (Regan, 1903, were examined with the goal to provide information about the diet of the species. Samples were collected off the southern coast of Rio de Janeiro, Brazil, near Ilha Grande, between January 2006 and August 2007, at a depth of about 60 m. The diet was analyzed by sex, maturity stages and quarterly to verify differences in the importance of food items. The latter were analyzed by: frequency of occurrence, percentage of weight and in the Alimentary Index. The trophic niche width was determined to assess the degree of specialization in the diet. Additionally, the degree of dietary overlap between males and females; juveniles and adults and periods of the year were defined. A total of 59 individuals of A. cyclophora were captured. Females and adults were more abundant. The quarters with the highest concentrations of individuals were in the summer of the Southern Hemisphere: Jan-Feb-Mar 06 and Jan-Feb-Mar 07. Prey items were classed into five main groups: Crustacea, Teleosts, Elasmobranchs, Polychaeta, and Nematoda. The most important groups in the diet of the eyespot skate were Crustacea and Teleosts. The crab Achelous spinicarpus (Stimpson, 1871 was the most important item. The value of the niche width was small, indicating that a few food items are important. The comparison of the diet between males and females and juveniles and adults indicates a significant overlap between the sexes and stages of maturity; and according to quarters, the importance of prey groups differed (crustaceans were more important in the quarters of the summer and teleost in Jul-Aug-Sep and Oct-Nov-Dec 06, indicating seasonal differences in diet composition. Three groups with similar diets were formed in the cluster analysis: (Jan-Feb-Mar 06 and 07; (Apr-May-Jun 06 and Jul-Aug-Sep 07; (Jul-Aug-Sep 06 and Oct-Nov-Dec 06.
Schwab, Sebastian; Memmert, Daniel
The aim of this study was to investigate whether a sports vision training program improves the visual performance of youth male field hockey players, ages 12 to 16 years, after an intervention of six weeks compared to a control group with no specific sports vision training. The choice reaction time task at the D2 board (Learning Task I), the functional field of view task (Learning Task II) and the multiple object tracking (MOT) task (Transfer Task) were assessed before and after the intervention and again six weeks after the second test. Analyzes showed significant differences between the two groups for the choice reaction time task at the D2 board and the functional field of view task, with significant improvements for the intervention group and none for the control group. For the transfer task, we could not find statistically significant improvements for either group. The results of this study are discussed in terms of theoretical and practical implications. Key pointsPerceptual training with youth field hockey playersCan a sports vision training program improve the visual performance of youth male field hockey players, ages 12 to 16 years, after an intervention of six weeks compared to a control group with no specific sports vision training?The intervention was performed in the "VisuLab" as DynamicEye(®) SportsVision Training at the German Sport University Cologne.We ran a series of 3 two-factor univariate analysis of variance (ANOVA) with repeated measures on both within subject independent variables (group; measuring point) to examine the effects on central perception, peripheral perception and choice reaction time.The present study shows an improvement of certain visual abilities with the help of the sports vision training program.
McDonald, John E; Herzog, Mackenzie M; Philippon, Marc J
Previous studies report professional athletes return to play following arthroscopic microfracture of the hip for chondral defects. Our hypothesis is that professional hockey players undergoing arthroscopic microfracture for chondral defects of the hip achieve the same performance they had pre-injury and compared to matched controls. Seventeen professional hockey players underwent arthroscopic microfracture for an Outerbridge grade IV chondral lesion. Concomitant procedures for labral pathology or FAI were included. Performance data for the full season preceding and following index procedure were analysed, in addition to two matched control players per subject. Data were collected at two points, 2 years apart. Eighty-two per cent (14/17) of players who underwent arthroscopic microfracture returned to play. The year prior to injury for the 14 players who returned was compared to the average of their individual controls. There was no statistical difference between the groups for age, number of seasons in the league, games played, time on ice, points, save percentage, and shots against goal. Post-operatively, there was no statistical difference between the treatment and control groups regarding performance measures. There was a trend towards a decrease in games played and points post-operatively compared with controls. The treatment group decreased 11 games played, while the controls decreased five games. The treatment group also decreased 14 points, while the controls decreased three points for the season. Professional hockey players with a discrete, full-thickness chondral defect of the hip are able to return to elite performance level following an arthroscopic microfracture procedure when compared to pre-injury outcomes and controls.
Body impact or collision is the risk factor underlying all sports-related concussions. This study sought to determine whether collision rates in elite hockey differ between games played on North American size rinks as compared to games played on larger international size ice surfaces. Videotapes of games from the 2001 and 2002 National Hockey League Stanley Cup finals, World Junior championships and the 2002 Winter Olympics were analyzed, with all collisions counted and separated into various categories (player/player bodycheck, player/player into boards, player/boards, player/ice, head/stick, head/puck). Further subdivisions included collisions involving the head directly or indirectly. Twenty-two games were analyzed, 11 played on the small ice and 11 on the big ice. Significantly more collisions of all types (in all categories and subdivisions within categories) were found to occur on the smaller North American ice surface (P value differences from 0.01 to 0.00001). The results of this study showed significantly fewer collisions of all types in elite hockey games played on the international size ice surface. The comparison groups studied here did differ in some aspects other than ice size and so replication of the findings with even more closely matched groups will be needed before definitive conclusions can be drawn. However, if these findings are replicable, it would suggest that a change to uniform usage of the larger international rinks, with no rule changes or other alterations in the game, could provide direct primary prevention to reduce the number of collisions, and, by extension, concussions, that occur in the sport.
Hänninen, Timo; Tuominen, Markku; Parkkari, Jari; Vartiainen, Matti; Öhman, Juha; Iverson, Grant L; Luoto, Teemu M
To determine normative reference values for the Sport Concussion Assessment Tool-3rd Edition (SCAT3) using a large sample of professional male ice hockey players. A descriptive cross-sectional study. Preseason baseline testing was administered individually to 304 professional male ice hockey players. The participants were aged between 16 and 40 with a mean (M) age of 25.3 years. Over 60% of the athletes reported previous concussion, almost 20% had been hospitalized or medically imaged following a head trauma. Of the players, 48% reported no symptoms. The symptom score median (Md) was 1.0 (M=1.5) and severity median was 1.0 (M=2.3). The median of the SAC score was 27.0 (M=27.0). The median of the M-BESS was 1.0 (M=2.0). The Tandem gait median was 10.9s (M=10.8s). The most common baseline symptom was neck pain (24%). Delayed recall was the most difficult component of the SAC (Md=4); only 24% performed it flawlessly. All athletes completed the double-leg stance of the M-BESS without errors, but there was performance variability in the tandem stance (Md=0, M=0.6, range=0-10) and single-leg stance (Md=1.0, M=1.4, range=0-10). Representative normative reference values for the SCAT3 among professional male ice hockey players are provided. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
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.
Blanco, Dr. Alfonso; Balagué, Dra. Natàlia
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...
Jakoi, Andre; O'Neill, Craig; Damsgaard, Christopher; Fehring, Keith; Tom, James
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
Tuominen, Markku; Stuart, Michael J; Aubry, Mark; Kannus, Pekka; Parkkari, Jari
Detailed injury data are not available for international ice hockey tournaments played by junior athletes. We report the incidence, type, mechanism and severity of injuries in males under ages 18 and 20 at junior ice hockey World Championships during 2006-2015. All injuries in the International Ice Hockey Federation World Junior under-20 (WJ U20) Championship and under-18 (WJ U18) Championship were collected over a 9-year period using a strict injury definition, a standardised injury reporting system and diagnoses made by a team physician. 633 injuries were recorded in 1326 games over a 9-year period, resulting in an injury rate (IR) of 11.0 per 1000 player-games and 39.8/1000 player-game hours. The IRs in all tournaments were 4.3/1000 player-games for the head and face, 3.2 for the upper body, 2.6 for the lower body and 1.0 for the spine and trunk. A laceration was the most common injury type followed by a sprain. Lacerations accounted for 80% (IR 3.6) of facial injuries in WJ U20 tournaments. The shoulder was the most common injury site (IR 2.0) in WJ U18 tournaments. Board contact was the mechanism for 59% of these shoulder injuries. Concussion was the most common head and face injury (46%; IR 1.2) in WJ U18 tournaments. The risk of injury among male junior ice hockey players was lower than the reported rates in adult men but higher than that in women. Facial lacerations were common in U20 junior players (WJ U20) since most wear only partial facial protection (visor). The IR for shoulder injuries was high in U18 junior players (WJ U18). Suggested strategies for injury prevention include full facial protection for all players and flexible board and glass for all junior tournaments. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
Hoch, Matthew C; Welsch, Lauren A; Hartley, Emily M; Powden, Cameron J; Hoch, Johanna M
The Y-Balance Test (YBT) is a dynamic balance assessment used as a preseason musculoskeletal screen to determine injury risk. While the YBT has demonstrated excellent test-retest reliability, it is unknown if YBT performance changes following participation in a competitive athletic season. Determine if a competitive athletic season affects YBT performance in field hockey players. Pretest-posttest. Laboratory. Twenty NCAA Division I women's field hockey players (age=19.55±1.30 years; height=165.10±5.277cm; mass=62.62±4.64kg) from a single team volunteered. Participants had to be free from injury throughout the entire study and participate in all athletic activities. Participants completed data collection sessions prior to (preseason) and following the athletic season (postseason). Between data collections, participants competed in the fall competitive field hockey season, which was ~3 months in duration. During data collection, participants completed the YBT bilaterally. The independent variable was time (preseason, postseason) and the dependent variables were normalized reach distances (anterior, posteromedial, posterolateral, composite) and between-limb symmetry for each reach direction. Differences between preseason and postseason were examined using paired t-tests (p≤0.05) as well as Bland-Altman limits of agreement. Four players sustained a lower extremity injury during the season and were excluded from analysis. There were no significant differences between preseason and postseason reach distances for any reach directions on either limb (p≥0.31) or in the between-limb symmetries (p≥0.52). The limits of agreement analyses determined there was a low mean bias across measurements (≤1.67%); however, the 95% confidence intervals indicated there was high variability within the posterior reach directions over time (±4.75-±14.83%). No changes in YBT performance were identified following a competitive field hockey season in Division I female athletes
Baker, Jonathan C; Hoover, Eric G; Hillen, Travis J; Smith, Matthew V; Wright, Rick W; Rubin, David A
In ice hockey players, serious bone injuries in the foot and ankle, especially those attributed to impact from the moving puck, may be radiographically occult and underrecognized. The purpose of this research was to study foot and ankle bone injuries detected with magnetic resonance imaging (MRI) that occurred in elite hockey players. The hypothesis was that these injuries predominate medially, especially when caused by the impact from the puck, and are associated with prolonged lost playing time. Case series; Level of evidence, 4. Three independent observers, blinded to the mechanism of injury, retrospectively reviewed foot and ankle MRI examinations acquired after 31 acute injuries that occurred in 27 elite ice hockey players who had no radiographically visible fractures. Bone abnormalities were classified as fractures or varying degrees of contusion based on predetermined definitions. Interobserver agreement was analyzed with kappa statistics. The association between the injury mechanism and the bones involved was examined with the Fisher exact test. A t test was applied to determine if MRI evidence of a severe bone injury (defined as either a fracture or a high-grade bone contusion) was associated with longer recovery times, when return-to-play information was available. The observers identified at least 1 bone injury in 27 of the 31 MRI examinations, including 10 with radiographically occult fractures. Agreement among the 3 observers for injury categorization was substantial (κ = 0.76). Seventeen injuries were caused by a direct blow (15 from a moving puck, 2 from an uncertain source), resulting in 6 fractures and 6 high-grade bone contusions, with 14 of the 17 involving a medial bone (medial malleolus, navicular, or first metatarsal base). Compared with other mechanisms, direct impaction was statistically more likely to result in a severe bone injury and to involve the medial foot and ankle. In 20 injuries where return-to-play information was available
Full Text Available The present paper analyses the diet, feeding strategy and niche width of B. macloviana in a sector of the Argentinean Continental Shelf (ACS. Individuals (n = 147 were collected from 43 sampling stations in late summer and autumn 2001. Thirty one alimentary items in the gut contents were found, with a clear dominance of polychaetes. Crustaceans were secondary alimentary items. The polychaete Travisia kerguelensis was the main food item ingested, followed by Nepthyidae, Sabellidae and Lumbrineridae, while Gammaridae and Cirolanidae were the main items among crustaceans. The niche width and feeding strategy displayed by B. macloviana support the specialisation towards polychaetes throughout this study. Slow motile and infaunal species constitute major preys. The results suggest that this skate actively selects worms, reflecting, in some sense, the composition of the polychaete assemblage, and allowing a low dietary overlap with other sympatric skates of the ACS.
Full Text Available Food habits of Bathyraja brachyurops were studied based on stomach content analyses of 346 specimens collected from research cruises carried out from 2003 to 2005 on the Argentinean continental shelf (36ºS-55ºS. A total of 265 stomachs (76.6% contained food, and thirty-five taxonomic levels of prey were identified. The most important prey were fishes followed by isopods. Trophic level analysis revealed that B. brachyurops is a tertiary consumer throughout its life history. There were no differences between sexes and regions in the diet composition, but dietary shifts with ontogeny were found. The Levins’ standardized index indicated wider niche breadth for small skates, whereas larger skate specimens showed a narrow niche breadth with a specialization in fishes.
Kim, Sungwoon; Kim, Jingu
To investigate the potential psychological benefits of brief exercise and sport activities on positive mood alterations, 45 Korean high school and 232 undergraduate students enrolled in physical education and stress management classes voluntarily participated and were randomly assigned to one of four activities: aerobic exercise, body conditioning, hip-hop dancing, and ice skating. Mood changes from before to after exercise (2 pm to 3 pm) were measured based on a Korean translation of the Subjective Exercise Experiences Scale. The findings suggested that the aerobics and hip-hop dancing groups rated positive well-being higher than the body conditioning and ice skating groups. Immediately after exercise, psychological distress was rated lower in the aerobics and hip-hop dancing groups, as was fatigue.
Hettinga, Florentina J; Konings, Marco J; Cooper, Chris E
Due to the technical nature of speed skating, that is affecting physiological mechanisms such as oxygenation and blood flow, this sport provides a unique setting allowing us to uncover novel mechanistic insights of the physiological response to exercise in elite middle-distance and endurance sports. The present study aimed to examine the influence of skating mode (short-track vs. long-track) on muscle oxygenation, perceived fatigue, and recovery in elite speed skating. Muscle oxygenation of 12 talented short-track speed skaters was continuously monitored during a long-track (LT) and a short-track (ST) skating time-trial of maximal effort using near-infrared spectroscopy (NIRS) on the m. vastus lateralis for both legs. Video captures were made of each testing session for further interpretation of the muscle oxygenation. To determine recovery, perceived exertion was measured 2 and 4 h after each testing sessions. Repeated measures ANOVA's were used for statistical analysis ( p muscle oxygenation between both legs was found during LT (tissue saturation-index (TSI%)-slope: left = 0.053 ± 0.032; right = 0.023 ± 0.020, p muscle oxygenation. Respectively, two ( ST = 5.8 ± 2.0; LT = 4.2 ± 1.5) and 4 h ( ST = 4.6 ± 1.9; LT = 3.1 ± 1.6) after the time-trials, a higher rate of perceived exertion was found for ST. Based on our results, ST seems more physiologically demanding, and longer periods of recovery are needed after training compared to LT. Technical aspects unique to the exercise mode seem to impact on oxygenation, affecting processes related to the regulation of exercise intensity such as fatigue and recovery.
King, Benjamin L.; Shi, Ling Fang; Kao, Peter; Clusin, William T.
Elasmobranchs detect small potentials using excitable cells of the ampulla of Lorenzini which have calcium-activated K+ channels, first described in l974. A distinctive feature of the outward current in voltage clamped ampullae is its apparent insensitivity to voltage. The sequence of a BK channel ? isoform expressed in the ampulla of the skate was characterized. A signal peptide is present at the beginning of the gene. When compared to human isoform 1 (the canonical sequence), the largest di...
Bustamante, Carlos; Lamilla, Julio; Concha, Francisco; Ebert, David A; Bennett, Michael B
Detailed descriptions of morphological features, morphometrics, neurocranium anatomy, clasper structure and egg case descriptions are provided for the thickbody skate Amblyraja frerichsi; a rare, deep-water species from Chile, Argentina and Falkland Islands. The species diagnosis is complemented from new observations and aspects such as colour, size and distribution are described. Geographic and bathymetric distributional ranges are discussed as relevant features of this taxońs biology. Additionally, the conservation status is assessed including bycatch records from Chilean fisheries.
Bustamante, Carlos; Lamilla, Julio; Concha, Francisco; Ebert, David A.; Bennett, Michael B.
Detailed descriptions of morphological features, morphometrics, neurocranium anatomy, clasper structure and egg case descriptions are provided for the thickbody skate Amblyraja frerichsi; a rare, deep-water species from Chile, Argentina and Falkland Islands. The species diagnosis is complemented from new observations and aspects such as colour, size and distribution are described. Geographic and bathymetric distributional ranges are discussed as relevant features of this taxońs biology. Additionally, the conservation status is assessed including bycatch records from Chilean fisheries. PMID:22768186
Foley, E C; Bird, H A
The interface between sports medicine and performing arts medicine is closest for "tariff" sports, where the sportsperson can select their own programme of varying difficulty with the more complex skills carrying potential for higher marks. Inevitably, some performers over-reach themselves. Examples of injuries and prevention strategies to avoid such injuries are discussed in a preliminary analysis of four sports: diving, cheerleading, gymnastics, and figure skating.
Nathanson, Brian H; Ribeiro, Kara; Henneman, Philip L
We analyzed the US incidence of emergency department (ED) visits and hospitalizations for falls from skiing, snowboarding, skateboarding, roller-skating, and nonmotorized scooters in 2011. The outcome was hospital admission from the ED. The primary analysis compared pediatric patients aged 1 to 17 years to adults aged 18 to 44 years. The analysis used ICD-9 E-codes E885.0 to E885.4 using discharge data from the Nationwide Emergency Department Sample, Healthcare Cost and Utilization Project, Agency for Healthcare Research and Quality. Approximately 214 000 ED visits met study criteria. Skiing injuries had the highest percentage of hospitalizations (3.30% in pediatric patients and 6.65% in adults 18-44 years old). Skateboard and snowboard injuries were more likely to require hospitalization than roller skating injuries in pediatric patients (odds ratio = 2.42; 95% CI = 2.14-2.75 and odds ratio = 1.83; 95% CI =1.55-2.15, respectively). In contrast, skateboard and snowboard injuries were less severe than roller-skating injuries in adults. © The Author(s) 2015.
Cicia, Angela M; Schlenker, Lela S; Sulikowski, James A; Mandelman, John W
Aerial exposure and acute thermal stress have been shown to elicit profound physiological disruptions in obligate water-breathing teleosts. However, no study has investigated these responses in an elasmobranch. To address this, venous blood samples were collected and evaluated from little skates (Leucoraja erinacea) subjected to discrete aerial exposure durations (0, 15, and 50 min) coupled with differing abrupt thermal changes (gradient between seawater and air; winter: ΔT=-3 °C; summer: ΔT=+9 °C) in two distinct laboratory studies. In general, blood acid-base properties (e.g. decline in pH; elevation in PCO(2)) and select metabolites (elevated whole-blood lactate) and electrolytes (elevated plasma K(+)) were significantly disrupted by aerial exposure, and were most disturbed after skates were exposed to air for 50 min. However, the magnitude of the blood acid-base perturbations, metabolic contribution to the resulting blood acidosis, elevations to ionic and metabolic parameters, and delayed mortality were more extreme during the summer study, suggesting that acute thermal stress exacerbates the physiological impairments associated with aerial exposure in little skates. Conversely, a reduced thermal gradient (from seawater to air) may attenuate the magnitude of metabolic and ionic perturbations, resulting in a high physiological threshold for coping with extended aerial exposure. Copyright © 2011 Elsevier Inc. All rights reserved.
White, William T; Last, Peter R; Mana, Ralph R
A new arhynchobatin skate, Notoraja sereti n. sp., is described based on three specimens collected from off Madang (Papua New Guinea) at depths of 800-980 m. This medium-size Notoraja skate shares with other velcro skates from the Western Pacific, N. alisae, N. fijiensis, N. inusitata and N. longiventralis, a ventral surface covering of fine denticles giving the skin a velvety feel. Notoraja sereti differs from all of these species in having a shorter snout (preorbital length 10.1-11.1 vs. 11.5-14.5% TL, prenasal length 8.2-8.9 vs, 9.8-12.1% TL), shorter head (dorsal head length 15.2-16.2 vs. 17.1-19.3% TL, ventral head length 21.6-22.9 vs. 22.9-25.9% TL), fewer pectoral-fin radials (total radials 58-60 vs. 61-74), and fewer vertebrae (predorsal diplospondylous centra 66-71 vs. 72-82, predorsal centra 90-95 vs. 98-107, total centra 126-131 vs. 135-152).
Fan, Tingjun; Jin, Lingyun; Wang, Xiaofeng
Effects of basic fibroblast growth factor (bFGF) and insulin-like growth factor II (IGF-II) on cartilage cells from proboscis of skate, Raja porasa Günther, were investigated in this study. The cartilage cells were cultured in 20% FBS-supplemented MEM medium at 24°C. Twelve hours after culture initiation, the cartilage cells were treated with bFGF and IGF-II at different concentration combinations. It was found that 20 ng/ml of bFGF or 80 ng/ml of IGF-II was enough to have obvious stimulating effect on the growth and division of skate cartilage cells. Test of bFGF and IGF-II together, revealed that 20 ng/ml of bFGF and 80 ng/ml of IGF-II together had the best stimulating effect on the growth and division of skate cartilage cells. The cartilage cells cultured could form a monolayer at day 7.
Griffiths, Andrew M; Sims, David W; Cotterell, Stephen P; El Nagar, Aliya; Ellis, Jim R; Lynghammar, Arve; McHugh, Matthew; Neat, Francis C; Pade, Nicolas G; Queiroz, Nuno; Serra-Pereira, Bárbara; Rapp, Toby; Wearmouth, Victoria J; Genner, Martin J
Many sharks and skates are particularly vulnerable to overfishing because of their large size, slow growth, late maturity and low fecundity. In Europe dramatic population declines have taken place in common skate (Dipturus batis L.), one of the largest demersal fish in regional shelf seas, leading to extirpations from substantial parts of its former range. Here we report the discovery of cryptic species in common skate collected from the northeast Atlantic continental shelf. Data from nuclear microsatellite markers indicated two clearly distinct clades and phylogenetic analysis of mitochondrial DNA sequences demonstrated monophyly of each one of them. Capture locations showed evidence of strong spatial segregation, with one taxon occurring mainly in waters off the southern British Isles and around Rockall, while the other was restricted to more northerly shelf waters. These apparently cryptic species showed overlapping substrate and depth preferences, but distributional limits were closely related to temperature gradients, potentially indicating thermal limits to their distributions. This discovery of hidden diversity within a large, critically endangered marine vertebrate demonstrates how marine biodiversity can be underestimated, even in such a relatively well-studied and heavily exploited region.
Tsutsui, Shigeyuki; Yamaguchi, Motoki; Hirasawa, Ai; Nakamura, Osamu; Watanabe, Tasuku
A lactose-specific lectin with a molecular mass of about 25 kDa was purified from the skin mucus of a cartilaginous fish-the common skate (Raja kenojei). The complementary DNA sequence of the lectin was 1540 bp long and contained a reading frame encoding 226 amino acids, which showed approximately 38% identity to pentraxins of mammals and teleosts. Gene expression was observed in the skin, gill, stomach and intestine in the healthy skate. We also identified an isotype gene from the liver whose deduced amino-acid sequence shared 69.0% identity with the skin type gene. The antiserum detected protein in the skin, where the lectin is localized in the epidermal cells, and in the blood plasma. The lectin genes are multicopied in the common skate genome. Although pentraxins are acute phase proteins, mRNAs of both the isotypes were not upregulated after the in vivo challenge with formalin-killed Escherichia coli, which suggests that they are constantly present in the skin mucus and blood plasma to protect against pathogenic invasion. This lectin is the fifth type of lectin found in the cutaneous secretions of fish, demonstrating that skin mucus lectins have evolved with marked molecular diversity in fish.
Griffiths, Andrew M.; Sims, David W.; Cotterell, Stephen P.; El Nagar, Aliya; Ellis, Jim R.; Lynghammar, Arve; McHugh, Matthew; Neat, Francis C.; Pade, Nicolas G.; Queiroz, Nuno; Serra-Pereira, Bárbara; Rapp, Toby; Wearmouth, Victoria J.; Genner, Martin J.
Many sharks and skates are particularly vulnerable to overfishing because of their large size, slow growth, late maturity and low fecundity. In Europe dramatic population declines have taken place in common skate (Dipturus batis L.), one of the largest demersal fish in regional shelf seas, leading to extirpations from substantial parts of its former range. Here we report the discovery of cryptic species in common skate collected from the northeast Atlantic continental shelf. Data from nuclear microsatellite markers indicated two clearly distinct clades and phylogenetic analysis of mitochondrial DNA sequences demonstrated monophyly of each one of them. Capture locations showed evidence of strong spatial segregation, with one taxon occurring mainly in waters off the southern British Isles and around Rockall, while the other was restricted to more northerly shelf waters. These apparently cryptic species showed overlapping substrate and depth preferences, but distributional limits were closely related to temperature gradients, potentially indicating thermal limits to their distributions. This discovery of hidden diversity within a large, critically endangered marine vertebrate demonstrates how marine biodiversity can be underestimated, even in such a relatively well-studied and heavily exploited region. PMID:20106849
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Laprade, Robert F; Surowiec, Rachel K; Sochanska, Ada N; Hentkowski, Brandon S; Martin, Brandie M; Engebretsen, Lars; Wijdicks, Coen A
Ice hockey is a high contact sport where players are inherently at an increased risk for traumatic and time-loss injury. With its increasing popularity and high incidence of injury, further research is necessary to understand the risks and injuries associated with the sport and to develop performance-based outcome measures to guide return to play. This review, tailored to the practicing sports medicine team physician, focuses on the stepwise identification, treatment, time loss, return to play and subsequent risk of injury for the most common areas of injury: the head, shoulder, hip and knee. Injuries were categorised into upper and lower extremity with an emphasis on glenohumeral and acromioclavicular joint injuries, femoroacetabular impingement, medial collateral ligament tears, and high ankle sprains. With return to play a primary goal for these high-level athletes, recovery in ice hockey becomes a complex issue with efficient protocols tailored to the requirements of the sport vital to the athlete and clinician alike. By reviewing the treatments and sport-specific care, athletes can be better managed with the ultimate goal of returning to their preinjury level of play. Level IV.
Harrison, Clive M
This paper generalizes 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' 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 Ph.D. 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.
García Tolosana, Carlos
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.
Jaakkola, T; Ntoumanis, N; Liukkonen, J
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.
Traclet, Alan; Moret, Orlan; Ohl, Fabien; Clémence, Alain
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.
Reed, N; Taha, T; Monette, G; Keightley, M
The objective of this study was to describe the effect of concussion on upper and lower body strength in children and youth athletes. The participant group was made up of 178 unique male and female ice hockey players (ages 8-14 years). Using a 3-year prospective longitudinal research design, baseline and post-concussion data on hand grip strength, jump tests, and leg maximal voluntary contraction were collected. Using a linear mixed-effects model, no significant differences were found when comparing the baseline strength performance of individuals who went on to experience a concussion and those who did not. When accounting for sex, multiple concussions, and ongoing changes in strength associated with age, weaker hand grip scores were found following concussion while participants were still symptomatic. Lower squat jump heights were achieved while participants were symptomatic as well as when they were no longer self-reporting symptoms associated with concussion. This study represents an initial step towards better understanding strength performance following concussion that may limit the on and off ice performance of youth ice hockey players, as well as predispose youth to subsequent injuries. © Georg Thieme Verlag KG Stuttgart · New York.
Douglas J. Mattson
Full Text Available The purpose of this study was to analyze injuries among adult recreational ice hockey players. This was an observational prospective cohort study with data collected on injuries sustained during one season in the adult recreational ice hockey leagues of Oneida County, NY. The injury incidence rate was found to be 12.2/1000 player-exposures. The most common anatomic region injured was the head/neck/face (35%. Collisions were most often reported as the mechanism of injury (44%. Fracture was the most common diagnosis. Of players wearing face protection (full cage or shield, or partial visor/half shield, none suffered facial injuries, while all facial injuries reported were to players not wearing facial protection. The concussion rate was 1.1/1000 player-exposures. A lack of protective equipment was associated with 38% of injuries and 24% of injuries involved penalties. A history of prior injuries was found in 89% of injured players with 28% re-injuring the same body part. This study's findings suggested various strategies to address player injuries such as mandatory full facial protection and shoulder pads, strict enforcement of game rules, and game rule modifications (no body checking. Further research is needed on the role of preventive rehabilitation in players with previous injury history.
Clive Maxwell Harrison
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.
Lax, Ilyse D; Paniccia, Melissa; Agnihotri, Sabrina; Reed, Nick; Garmaise, Evan; Azadbakhsh, Mahdis; Ng, Justin; Monette, Georges; Wiseman-Hakes, Catherine; Taha, Tim; Keightley, Michelle
Concussion is the most common athletic injury in youth who are simultaneously undergoing rapid developmental changes in the brain, specifically the development of executive functions (EF). The developing brain is more vulnerable to concussive injury with a protracted and different trajectory of recovery than that of adults. Thus, there is a critical need to enhance understanding of how concussion affects EF in youth. To investigate the effects of age, gender and concussion history (i.e. concussion incidence, recency, severity) on EF in youth hockey players. This 3-year cross-sectional and longitudinal multiple cohort study examined data from 211 hockey players of 8-15 years of age. Mixed-effects modelling was used to examine the influence of age, gender and concussion on EF in youth athletes. Baseline analyses revealed significant age and gender effects on measures of EF. Multiple effects of concussion history on measures of cognitive flexibility (F = 2.48, p = 0.03) and psychomotor speed (F = 2.59, p = 0.04) were found. This study highlights the impact of age, gender and concussion on EF in youth. These findings provide foundational knowledge to better manage cognitive sequelae following sports-related concussion.
Schneider, Ray; Harrington, Mike; Tobar, David
The purpose of this study was to examine goal orientation in college hockey players. Specifically, how a task or ego orientation can affect enjoyment. The Task and Ego Orientation Sport Questionnaire (TEOSQ) was used to determine goal orientation as either task or ego, and the Physical Activity Enjoyment Scales (PACES) measured how much…
This study was conducted for determining the effects of trainings, applied to athletes during short term camp period, on their aerobic and anaerobic performance. Measurements were made by the participation of 28 volunteer male ice hockey national team players. During the 15-day camp period, 10-minute running and stretching for warming and then…
Gouttebarge, Vincent; Kerkhoffs, Gino M. M. J.
Objectives: Scientific knowledge about symptoms of common mental disorders in professional ice hockey is lacking. Consequently, the primary aims of the study were to (i) determine the prevalence, comorbidity and 6-month incidence of symptoms of common mental disorders (distress, anxiety/ depression,
Agel, Julie; Harvey, Edward J.
Background Ice hockey is a high-speed collision sport with recognized injury potential. Body checking, identified as a primary cause of injury, is allowed in men’s hockey but is not allowed at any level for female players. The injury patterns in collegiate hockey should reflect this fundamental difference in how the game is played. In this study, we reviewed the injuries sustained by National Collegiate Athletic Association (NCAA) hockey players over a 7-year period. Methods We conducted a retrospective database review of injuries and exposures reported to the Injury Surveillance System to determine rates of injury or differences in the pattern of injury between the sexes. Results The rate of injury during games for men (18.69/1000 athlete-exposures [AEs]) and women (12.10/1000 AEs) was significantly higher than the rate of injury during practice. The rate of concussion was 0.72/1000 AEs for men and 0.82/1000 AEs for women, and the rate remained stable over the study period. Player contact was the cause of concussions in game situations for 41% of women and 72% of men. Conclusion Both men and women had increased rates of practice-related injuries that resulted in time loss during the study period. In addition, there were high rates of concussions from player contact. The concussion rate in women was higher than expected. A more detailed examination with focused data collection may impact these findings. PMID:20858376
Hawn, Kristen L.; Visser, Mary Frances; Sexton, Patrick J.
Investigated enforcement patterns and athlete compliance with the National Collegiate Athletic Association rule requiring the wearing of mouthguards in men's collegiate ice hockey games during one season. Surveys of athletic trainers indicated that the use of mouthguards in competition was not consistently enforced by athletic trainers, coaches,…
Linseman, Mark E; Palmer, Matthew S; Sprenger, Heather M; Spriet, Lawrence L
Research in "stop-and-go" sports has demonstrated that carbohydrate ingestion improves performance and fatigue, and that dehydration of ∼1.5%-2% body mass (BM) loss results in decreased performance, increased fatigue, and increased core temperature. The purpose of this investigation was to assess the physiological, performance, and fatigue-related effects of maintaining hydration with a carbohydrate-electrolyte solution (CES) versus dehydrating by ∼2% BM (no fluid; NF) during a 70-min ice hockey scrimmage. Skilled male hockey players (n = 14; age, 21.3 ± 0.2 years; BM, 80.1 ± 2.5 kg; height, 182.0 ± 1.2 cm) volunteered for the study. Subjects lost 1.94% ± 0.1% BM in NF, and 0.12% ± 0.1% BM in CES. Core temperature (Tc) throughout the scrimmage (10-50 min) and peak Tc (CES: 38.69 ± 0.10 vs. NF: 38.92 ± 0.11 °C; p hockey scrimmage resulted in improved hockey performance and thermoregulation, and decreased fatigue as compared with drinking no fluid and dehydrating by ∼2%.
Cheryl A. MacDonald
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.
Full Text Available Material about the level of development of training process in hockey is resulted. Directions of construction of training process of hockey players, applications of different facilities and methods of preparation are considered. Opinions of specialists in this type of sport are studied. The ways of optimization of training process are resulted. It is expounded information about the changes of indexes of D&K-test of testing of hockey players at the individual construction of seasonal preparation and in transition on the command training program. Loadings given about different influence are confirmed with one orientation on the sportsmen of different biotpower groups of D&K-test.
Full Text Available Olufemi R Ayeni,1 Marcin Kowalczuk,1 Jordan Farag,1 Forough Farrokhyar,1,2 Raymond Chu,1 Asheesh Bedi,3 Kevin Willits,4 Mohit Bhandari1,2 1Division of Orthopaedic Surgery, Department of Surgery, 2Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada; 3Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA; 4Department of Orthopaedic Surgery, University of Western Ontario, London, ON, Canada Background: There has been a noted increase in the diagnosis and reporting of sporting hip injuries and conditions in the medical literature but reporting at the minor hockey level is unknown. The purpose of this study is to investigate the trend of reporting hip injuries in amateur ice hockey players in Canada with a focus on injury type and mechanism. Methods: A retrospective review of the Hockey Canada insurance database was performed and data on ice hockey hip injuries reported between January 2005 and June 2011 were collected. The study population included all male hockey players from Peewee (aged 11–12 years to Senior (aged 20+ years participating in amateur level competition sanctioned by Hockey Canada. Reported cases of ice hockey hip injuries were analyzed according to age, mechanism of injury, and injury subtype. Annual injury reporting rates were determined and using a linear regression analysis trended to determine the change in ice hockey hip injury reporting rate over time. Results: One hundred and six cases of ice hockey-related hip injuries were reported in total. The majority of injuries (75.5% occurred in players aged 15–20 years playing at the Junior level. Most injuries were caused by a noncontact mechanism (40.6% and strains were the most common subtype (50.0%. From 2005 to 2010, the number of reported hip injuries increased by 5.31 cases per year and the rate of reported hip injury per 1,000 registered players increased by 0.02 cases annually. Conclusion: Reporting of
Echlin, Paul Sean; Tator, Charles H; Cusimano, Michael D; Cantu, Robert C; Taunton, Jack E; Upshur, Ross E G; Hall, Craig R; Johnson, Andrew M; Forwell, Lorie A; Skopelja, Elaine N
The objective of this study was to measure the incidence of concussion (scaled relative to number of athlete exposures) and recurrent concussion within 2 teams of fourth-tier junior ice hockey players (16-21 years old) during 1 regular season. A prospective cohort study called the Hockey Concussion Education Project was conducted during 1 junior ice hockey regular season (2009-2010) involving 67 male fourth-tier ice hockey players (mean age 18.2 ± 1.2 years, range 16-21 years) from 2 teams. Prior to the start of the season, every player underwent baseline assessments 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 baseline SCAT2 and ImPACT testing. If the protocol was not followed, the postinjury test results of a player without true baseline test results would be compared against previously established age and gender group normative levels. Each regular season game was observed by a qualified physician and at least 1 other neutral nonphysician observer. Players who suffered a suspected concussion were evaluated at the game. If a concussion diagnosis was made, the player was subsequently examined in the physician's office for a full clinical evaluation and the SCAT2 and ImPACT were repeated. Based on these evaluations, players were counseled on the decision of when to return to play. Athlete exposure was defined as 1 game played by 1 athlete. Twenty-one concussions occurred during the 52 physician-observed games (incidence 21.5 concussions per 1000 athlete exposures). Five players experienced repeat concussions. No concussions were reported during practice sessions. A concussion was diagnosed by the physician in 19 (36.5%) of the 52 observed games. One of the 5 individuals who suffered a repeat concussion sustained his initial concussion in a regular season game that was not observed by a
Full Text Available Jean-François Brunelle,1,2 Sébastien Blais-Coutu,1 Kenan Gouadec,3 Éric Bédard,3 Philippe Fait1,2 1Department of Human Kinetics Sciences, 2Research Group on Neuromusculoskeletal Dysfunctions, Université du Québec à Trois-Rivières, QC, Canada; 3Italian Ice Sports Federation, Rome, Italy Introduction: In preparation for a short track speed skating season, eight men and seven women were given yoga sessions during an 8-week high volume training cycle. The sessions were planned according to the postural aspects specific to short track speed skating technical requirements. Three specific goals were selected for the intervention: 1 to observe whether the practice of yoga as postural training could improve the efficiency and the athlete's repertoire along the muscular synergies solicited in the short track speed skating specific technique; 2 to enhance and diversify the motor time-on-task of athletes without changing the prescription of other training stimulus; and 3 to lower the risk of injury during periods with high volumes of training. Methods: A total of 36 sessions of yoga were given. Three postural tests were administered before and after the intervention with 14 angles analyzed. Non-parametric Wilcoxon test was used to compare angles' variations. Results: The 36 yoga sessions totalized 986 minutes of motor time-on-task, registering a proportion of 30% of the global motor time-on-task of the training cycle. Improvements were found in eleven of the 14 angles measured when comparing pre- and post-postural tests (P-value from 0.01 to 0.005. During the 8 weeks, excepting traumatic injuries due to short track speed skating accidents, no skaters suffered injuries linked to the high volume of training. Following the intervention, coaches noticed, following their on-ice feedbacks, an adjustment in the efficiency of the skating technique, in particular regarding hip dissociation. Conclusion: These results suggest that yoga could be inserted into
Tuominen, Markku; Stuart, Michael J; Aubry, Mark; Kannus, Pekka; Tokola, Kari; Parkkari, Jari
We report the incidence, type, mechanism and severity of ice hockey injuries in women's international ice hockey championships. All injuries in the International Ice Hockey Federation World Women's Championship, World Women's under-18 Championship and Olympic Winter Games tournaments were analysed over an 8-year period using a strict injury definition, standardised reporting and team physician diagnosis. 168 injuries were recorded in 637 games over an 8-year period resulting in an injury rate (IR) of 6.4 per 1000 player-games and 22.0/1000 player-game hours. The IRs were 2.7/1000 player-games for the lower body, 1.4 for the upper body, 1.3 for the head and face and 0.9 for the spine and trunk. Contusion was the most common injury followed by a sprain. The most commonly injured site was the knee (48.6% of lower body injuries; IR 1.3/1000 player-games). The Medial collateral ligament sprain occurred in 37.1% and ACL rupture in 11.4% of knee injuries. A concussion (74.3%; IR 1.0/1000 player-games) was the most common head injury. The risk of injury to female ice hockey players at World Championship and Olympic tournaments was about half of that observed in the men's Championships. Full facial protection decreases the risk of lacerations and should be continued in all future female tournaments. More effective prevention strategies for knee, ankle and shoulder injuries are needed in women's ice hockey. Improved concussion education is necessary to promote more consistent diagnosis and return to play protocols. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
Helmer, Karl G.; Pasternak, Ofer; Fredman, Eli; Preciado, Ronny I.; Koerte, Inga K.; Sasaki, Takeshi; Mayinger, Michael; Johnson, Andrew M.; Holmes, Jeffrey D.; Forwell, Lorie; Skopelja, Elaine N.; Shenton, Martha E.; Echlin, Paul S.
Object Concussion, or mild traumatic brain injury (mTBI), is a commonly occurring sports-related injury, especially in contact sports such as hockey. Cerebral microbleeds (CMBs), which are small, hypointense lesions on T2*-weighted images, can result from TBI. The authors use susceptibility-weighted imaging (SWI) to automatically detect small hypointensities that may be subtle signs of chronic and acute damage due to both subconcussive and concussive injury. The goal was to investigate how the burden of these hypointensities change over time, over a playing season, and postconcussion, compared with subjects who did not suffer a medically observed and diagnosed concussion. Methods Images were obtained in 45 university-level adult male and female ice hockey players before and after a single Canadian Interuniversity Sports season. In addition, 11 subjects (5 men and 6 women) underwent imaging at 72 hours, 2 weeks, and 2 months after concussion. To identify subtle changes in brain tissue and potential CMBs, nonvessel clusters of hypointensities on SWI were automatically identified and a hypointensity burden index was calculated for all subjects at the beginning of the season (BOS) and the end of the season (EOS), in addition to postconcussion time points (where applicable). Results A statistically significant increase in the hypointensity burden, relative to the BOS, was observed for male subjects at the 2-week postconcussion time point. A smaller, nonsignificant rise in the burden for all female subjects was also observed within the same time period. The difference in hypointensity burden was also statistically significant for men with concussions between the 2-week time point and the BOS. There were no significant changes in burden for nonconcussed subjects of either sex between the BOS and EOS time points. However, there was a statistically significant difference in the burden between male and female subjects in the nonconcussed group at both the BOS and EOS time
Helmer, Karl G; Pasternak, Ofer; Fredman, Eli; Preciado, Ronny I; Koerte, Inga K; Sasaki, Takeshi; Mayinger, Michael; Johnson, Andrew M; Holmes, Jeffrey D; Forwell, Lorie A; Skopelja, Elaine N; Shenton, Martha E; Echlin, Paul S
Concussion, or mild traumatic brain injury (mTBI), is a commonly occurring sports-related injury, especially in contact sports such as hockey. Cerebral microbleeds (CMBs), which appear as small, hypointense lesions on T₂*-weighted images, can result from TBI. The authors use susceptibility-weighted imaging (SWI) to automatically detect small hypointensities that may be subtle signs of chronic and acute damage due to both subconcussive and concussive injury. The goal was to investigate how the burden of these hypointensities changes over time, over a playing season, and postconcussion, in comparison with subjects who did not suffer a medically observed and diagnosed concussion. Images were obtained in 45 university-level adult male and female ice hockey players before and after a single Canadian Interuniversity Sports season. In addition, 11 subjects (5 men and 6 women) underwent imaging at 72 hours, 2 weeks, and 2 months after concussion. To identify subtle changes in brain tissue and potential CMBs, nonvessel clusters of hypointensities on SWI were automatically identified, and a hypointensity burden index was calculated for all subjects at the beginning of the season (BOS), the end of the season (EOS), and at postconcussion time points (where applicable). A statistically significant increase in the hypointensity burden, relative to the BOS, was observed for male subjects with concussions at the 2-week postconcussion time point. A smaller, nonsignificant rise in the burden for female subjects with concussions was also observed within the same time period. There were no significant changes in burden for nonconcussed subjects of either sex between the BOS and EOS time points. However, there was a statistically significant difference in the burden between male and female subjects in the nonconcussed group at both the BOS and EOS time points, with males having a higher burden. This method extends the utility of SWI from the enhancement and detection of larger (> 5
Full Text Available Os esportes radicais têm sido objetos de discussões, devido ao interesse de aplicabilidade de seus conteúdos relacionados ao lazer, ao esporte e a educação. Todavia, ainda há certo despreparo profissional para empreender essas atividades, o que dificulta implantar tais práticas nos âmbitos educacionais. Este estudo, de natureza qualitativa, teve como objetivo apresentar uma proposta metodológica para organização de um curso de extensão universitária para graduandos e professores de educação física, com a finalidade de promover reflexões sobre os processos de iniciação à prática do skate atrelados ao esporte educacional. O estudo constou de pesquisa bibliográfica, apoiada em levantamentos de artigos, teses, dissertações, livros e sites, em que se relacionavam a prática do skate e sua ação educativa. Além disso, houve uma proposição de implementar uma proposta metodológica, no sentido de complementar os elementos da cultura corporal a ser vivenciada em âmbito escolar e efetivamente contribuir no processo de desenvolvimento do ser humano nos aspectos biológico, psicológico, social e cultural.The radical sports have been discussions' objects due to the interest of applicability of its contents related to leisure, sport, and education. Nevertheless, there is still some professional unprepared to undertake these activities, which makes difficult to introduce these practices in the educational ambit. This study, which has a qualitative character, had the aim to present a methodological proposal of organizing a college extension course for undergraduate students and teachers of physical education with the goal of promoting reflections about the processes of starting in the skateboarding practice coupled to educational sport. The study was consisted of a bibliographic research supported by a survey of articles, thesis, dissertations, books and, websites related to the skateboarding practice and its educative action
Criswell, Katharine E; Coates, Michael I; Gillis, J Andrew
The morphological patterns and molecular mechanisms of vertebral column development are well understood in bony fishes (osteichthyans). However, vertebral column morphology in elasmobranch chondrichthyans (e.g., sharks and skates) differs from that of osteichthyans, and its development has not been extensively studied. Here, we characterize vertebral development in an elasmobranch fish, the little skate, Leucoraja erinacea, using microCT, paraffin histology, and whole-mount skeletal preparations. Vertebral development begins with the condensation of mesenchyme, first around the notochord, and subsequently around the neural tube and caudal artery and vein. Mesenchyme surrounding the notochord differentiates into a continuous sheath of spindle-shaped cells, which forms the precursor to the mineralized areolar calcification of the centrum. Mesenchyme around the neural tube and caudal artery/vein becomes united by a population of mesenchymal cells that condenses lateral to the sheath of spindle-shaped cells, with this mesenchymal complex eventually differentiating into the hyaline cartilage of the future neural arches, hemal arches, and outer centrum. The initially continuous layers of areolar tissue and outer hyaline cartilage eventually subdivide into discrete centra and arches, with the notochord constricted in the center of each vertebra by a late-forming "inner layer" of hyaline cartilage, and by a ring of areolar calcification located medial to the outer vertebral cartilage. The vertebrae of elasmobranchs are distinct among vertebrates, both in terms of their composition (i.e., with centra consisting of up to three tissues layers-an inner cartilage layer, a calcified areolar ring, and an outer layer of hyaline cartilage), and their mode of development (i.e., the subdivision of arch and outer centrum cartilage from an initially continuous layer of hyaline cartilage). Given the evident variation in patterns of vertebral construction, broad taxon sampling, and
From coexistence to competitive exclusion: can overfishing change the outcome of competition in skates (Chondrichthyes, Rajidae? De la coexistencia a la exclusión competitiva: ¿Puede la sobrepesca cambiar el resultado de la competencia en rayas (Chondrichthyes, Rajidae?
Natalia L Ruocco
Full Text Available Competition for food could be a major force driving changes in the community structure of skates (Rajidae subjected to fishing exploitation. Under this hypothesis, small skates are released from competition with larger skates after fishing has depleted the larger species. Here, we compare the abundance patterns of two sympatric skates with similar niches but different life histories, Bathyraja albomaculata (larger and slow-reproducing and Bathyraja macloviana (smaller and faster-reproducing, before (1971, 1978 and after (1998-2004 a 108% increase in industrial bottom trawling on the southeastern South American shelf in order to test the prediction that B. macloviana should competitively exclude B. albomaculata after the increase in fishing mortality. In 1971 and 1978, there was no relationship between the abundance of both species, indicating that they coexisted over large scales. In 1998-2004, the relationship between the abundances of these skates was bell-shaped, indicating that both species increased in abundance at low densities until peaking, after which B. albomaculata decreased when B. macloviana became more abundant, consistent with resource competition. We tested whether food may be a potential limiting resource by comparing the diet of both species. The two species consumed mostly polychaetes, differing only in the consumption of polychaetes from the family Nephthyidae, which was much higher for B. macloviana. Bathyraja macloviana could replace B. albomaculata at high densities when food resources may become scarce. These results support the hypothesis that competition release is an important factor explaining the changes in skate communities in overexploited areas.La competencia por el alimento podría ser una fuerza importante detrás de los cambios en la estructura de las comunidades de rayas (Rajidae bajo explotación pesquera. Según esta hipótesis, las rayas pequeñas son liberadas de la competencia por las rayas de mayor tama
A esportivização do skate (1960-1990: relações entre o macro e o micro La deportivización del skate (1960-1990: relaciones entre lo macro y micro The sportivization of skateboarding (1960-1990: relations between the macro and the micro
Full Text Available O objetivo deste estudo foi apresentar elementos da esportivização da prática cultural skate (1960-1990, como conhecimento para o entendimento da relação entre o micro e o macro processo sócio-histórico do skate. Como fonte de pesquisa histórica para a esportivização do skate no Brasil, dimensão macro, utilizamos a Revista Tribo Skate e para a de Piracicaba/SP, dimensão micro, entrevistamos dois colaboradores a partir do método da história oral. Os resultados evidenciaram que o skate surgiu para gerar fortes tensões agradáveis, suas formas de lazer precedem as formas esportivas e, guardadas as particularidades, os seus processos macro e micro-históricos são interdependentes.El objetivo del estudio fue presentar elementos de la deportivización de la práctica cultural skate (1960-1990, como conocimiento para el entendimiento de la relación entre el micro y macro proceso socio-histórico del mismo. Como fuente de investigación histórica para la deportivización del skate en Brasil, dimensión macro, utilizamos la Revista Tribo Skate y para la de Piracicaba/SP, dimensión micro, entrevistamos dos colaboradores a partir del método de historia oral. Los resultados evidenciaron que el skate surgió para generar fuertes tensiones agradables, sus formas de ocio preceden a sus formas deportivas y, salvando las particularidades, los procesos macro y micro-históricos son interdependientes.The objective of this study is to present the elements of the sportivization of the cultural practice of skateboarding (1960-1990, as knowledge for the understanding of the relation between the micro and the macro social and historical processes of skateboarding. We used the magazine Revista Tribo Skate as source of historical research for the sportivization of skateboarding in Brazil, the macro dimension, and for the micro dimension, the city of Piracicaba/SP, where we interviewed two collaborators based on the method of oral history. The results
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.
Naylor, Kyla L.; McKenzie, Susan; Cherry, Cindy; McArthur, Eric; Li, Alvin H.; McCallum, Megan K.; Kim, S. Joseph; Prakash, Versha; Knoll, Gregory A.; Garg, Amit X.
Background: The Kidney Foundation of Canada developed a pilot campaign to educate persons attending junior hockey league games in London, Ontario, Canada, on deceased organ donation. Objective: To evaluate the impact of a hockey campaign on the number of new organ and tissue donor registrants. Design: Population-based retrospective cohort study. Setting: Residents of London, Ontario. Patients: We included 255 476 individuals eligible to register for organ donation with a London, Ontario postal code. Measurements: We compared the number of new deceased organ donor registrants in London, Ontario, during the campaign period (March 12 to April 16, 2015) with 3 different time periods (December 30, 2014 to February 3, 2015; February 4 to March 11, 2015; April 17 to May 22, 2015). We also compared registration rates in London with 2 Ontario cities (Kitchener-Waterloo and Hamilton) matching in a 1:1 ratio on age, sex, and income quintile. Methods: To compare registrations across time periods, we used binomial regression with an identity link function and generalized estimating equations with an independence correlation structure. We used modified Poisson regression to compare registration rates between cities. Results: During the campaign period, there were slightly more registrations (1218 registered of 252 832 unregistered individuals [0.48%]) compared with an earlier time period (risk difference: 0.09%; 95% confidence interval [CI]: 0.05%-0.12%). However, there was no significant difference compared with 2 time periods immediately before and after the campaign. London had slightly more registrations during the campaign period compared with the matched city of Hamilton (1180 registered of 236 582 unregistered individuals [0.50%] vs 490 registered of 236 582 unregistered individuals [0.21%]; risk ratio: 2.41; 95% CI: 2.17-2.68). The registration rate in London did not significantly differ from Kitchener-Waterloo. Limitations: Unable to conclude whether the minor increase
Tramer, Joseph S; Deneweth, Jessica M; Whiteside, David; Ross, James R; Bedi, Asheesh; Goulet, Grant C
Femoroacetabular impingement (FAI) is a major cause of performance inhibition in elite-level athletes. The condition is characterized by pain, osseous abnormalities such as an increased alpha angle, and decreased range of motion at the affected hip joint. Arthroscopic surgical decompression is useful in reshaping the joint to alleviate symptoms. Functional kinematic outcomes of sport-specific movements after surgery, however, are presently unknown. The ability of an ice hockey goaltender to execute sport-specific movements would improve after arthroscopic surgery. Clinical research. Level 5. An ice hockey goaltender was evaluated after arthroscopic correction of FAI on the symptomatic hip. Passive range of motion and radiographic parameters were assessed from a computed tomography-derived 3-dimensional model. An on-ice motion capture system was also used to determine peak femoral shock and concurrent hip joint postures during the butterfly and braking movements. Maximum alpha angles were 47° in the surgical and 61° in the nonsurgical hip. Internal rotation range of motion was, on average, 23° greater in the surgically corrected hip compared with contralateral. Peak shock was lower in the surgical hip by 1.39 g and 0.86 g during butterfly and braking, respectively. At peak shock, the surgical hip demonstrated increased flexion, adduction, and internal rotation for both tasks (butterfly, 6.1°, 12.3°, and 30.8°; braking, 14.8°, 19.2°, and 41.4°). On-ice motion capture revealed performance differences between hips after arthroscopic surgery in a hockey goaltender. Range of motion and the patient's subjective assessment of hip function were improved in the surgical hip. While presenting as asymptomatic, it was discovered that the contralateral hip displayed measurements consistent with FAI. Therefore, consideration of preemptive treatment in a presently painless hip may be deemed beneficial for young athletes seeking a long career in sport, and future work is
Lacny, Sarah; Marshall, Deborah A; Currie, Gillian; Kulin, Nathalie A; Meeuwisse, Willem H; Kang, Jian; Emery, Carolyn A
The risk of injury among Pee Wee (ages 11-12 years) ice hockey players in leagues that allow body checking is threefold greater than in leagues that do not allow body checking. We estimated the cost-effectiveness of a no body checking policy versus a policy that allows body checking in Pee Wee ice hockey. Cost-effectiveness analysis alongside a prospective cohort study during the 2007-2008 season, including players in Quebec (n=1046), where policy did not allow body checking, and in Alberta (n=1108), where body checking was allowed. Injury incidence rates (injuries/1000 player-hours) and incidence proportions (injuries/100 players), adjusted for cluster using Poisson regression, allowed for standardised comparisons and meaningful translation to community stakeholders. Based on Alberta fee schedules, direct healthcare costs (physician visits, imaging, procedures) were adjusted for cluster using bootstrapping. We examined uncertainty in our estimates using cost-effectiveness planes. Associated with significantly higher injury rates, healthcare costs where policy allowed body checking were over 2.5 times higher than where policy disallowed body checking ($C473/1000 player-hours (95% CI $C358 to $C603) vs $C184/1000 player-hours (95% CI $C120 to $C257)). The difference in costs between provinces was $C289/1000 player-hours (95% CI $C153 to $C432). Projecting results onto Alberta Pee Wee players registered in the 2011-2012 season, an estimated 1273 injuries and $C213 280 in healthcare costs would be avoided during just one season with the policy change. Our study suggests that a policy disallowing body checking in Pee Wee ice hockey is cost-saving (associated with fewer injuries and lower costs) compared to a policy allowing body checking. As we did not account for long-term outcomes, our results underestimate the economic impact of these injuries. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please
Schmidt, Julianne D; Pierce, Alice F; Guskiewicz, Kevin M; Register-Mihalik, Johna K; Pamukoff, Derek N; Mihalik, Jason P
Addressing safe-play knowledge and player aggression could potentially improve ice hockey sport safety. To compare (1) safe-play knowledge and aggression between male and female adolescent ice hockey players and (2) head-impact frequency and severity between players with high and low levels of safe-play knowledge and aggression during practices and games. Cohort study. On field. Forty-one male (n = 29) and female (n = 12) adolescent ice hockey players. Players completed the Safe Play Questionnaire (0 = less knowledge, 7 = most knowledge) and Competitive Aggressiveness and Anger Scale (12 = less aggressive, 60 = most aggressive) at midseason. Aggressive penalty minutes were recorded throughout the season. The Head Impact Telemetry System was used to capture head-impact frequency and severity (linear acceleration [g], rotational acceleration [rad/s(2)], Head Impact Technology severity profile) at practices and games. One-way analyses of variance were used to compare safe play knowledge and aggression between sexes. Players were categorized as having high or low safe-play knowledge and aggression using a median split. A 2 × 2 mixed-model analysis of variance was used to compare head-impact frequency, and random-intercept general linear models were used to compare head-impact severity between groups (high, low) and event types (practice, game). Boys (5.8 of 7 total; 95% confidence interval [CI] = 5.3, 6.3) had a trend toward better safe-play knowledge compared with girls (4.9 of 7 total; 95% CI = 3.9, 5.9; F1,36 = 3.40, P = .073). Less aggressive male players sustained significantly lower head rotational accelerations during practices (1512.8 rad/s (2) , 95% CI = 1397.3, 1637.6 rad/s(2)) versus games (1754.8 rad/s (2) , 95% CI = 1623.9, 1896.2 rad/s(2)) and versus high-aggression players during practices (1773.5 rad/s (2) , 95% CI = 1607.9, 1956.3 rad/s (2) ; F1,26 = 6.04, P = .021). Coaches and sports medicine professionals should ensure that athletes of all levels
Naylor, Kyla L; McKenzie, Susan; Cherry, Cindy; McArthur, Eric; Li, Alvin H; McCallum, Megan K; Kim, S Joseph; Prakash, Versha; Knoll, Gregory A; Garg, Amit X
The Kidney Foundation of Canada developed a pilot campaign to educate persons attending junior hockey league games in London, Ontario, Canada, on deceased organ donation. To evaluate the impact of a hockey campaign on the number of new organ and tissue donor registrants. Population-based retrospective cohort study. Residents of London, Ontario. We included 255 476 individuals eligible to register for organ donation with a London, Ontario postal code. We compared the number of new deceased organ donor registrants in London, Ontario, during the campaign period (March 12 to April 16, 2015) with 3 different time periods (December 30, 2014 to February 3, 2015; February 4 to March 11, 2015; April 17 to May 22, 2015). We also compared registration rates in London with 2 Ontario cities (Kitchener-Waterloo and Hamilton) matching in a 1:1 ratio on age, sex, and income quintile. To compare registrations across time periods, we used binomial regression with an identity link function and generalized estimating equations with an independence correlation structure. We used modified Poisson regression to compare registration rates between cities. During the campaign period, there were slightly more registrations (1218 registered of 252 832 unregistered individuals [0.48%]) compared with an earlier time period (risk difference: 0.09%; 95% confidence interval [CI]: 0.05%-0.12%). However, there was no significant difference compared with 2 time periods immediately before and after the campaign. London had slightly more registrations during the campaign period compared with the matched city of Hamilton (1180 registered of 236 582 unregistered individuals [0.50%] vs 490 registered of 236 582 unregistered individuals [0.21%]; risk ratio: 2.41; 95% CI: 2.17-2.68). The registration rate in London did not significantly differ from Kitchener-Waterloo. Unable to conclude whether the minor increase in deceased organ donor registration was the result of the campaign or other factors (e
Full Text Available Chondrichthyan fishes are a diverse class of gnathostomes that provide a valuable perspective on fundamental characteristics shared by all jawed and limbed vertebrates. Studies of phylogeny, species diversity, population structure, conservation, and physiology are accelerated by genomic, transcriptomic and protein sequence data. These data are widely available for many sarcopterygii (coelacanth, lungfish and tetrapods and actinoptergii (ray-finned fish including teleosts taxa, but limited for chondrichthyan fishes. In this study, we summarize available data for chondrichthyes and describe resources for one of the largest projects to characterize one of these fish, Leucoraja erinacea, the little skate. SkateBase (http://skatebase.org serves as the skate genome project portal linking data, research tools, and teaching resources.
Delpiani, G; Spath, M C; Deli Antoni, M; Delpiani, M
A description of the tooth morphology of 234 jaws from the southern thorny skate Amblyraja doellojuradoi in the south-west Atlantic Ocean is given. Seven rows of teeth were selected and length and width of each tooth in these rows were measured. It was found that functional series corresponds to the third teeth and the average width and length of these teeth were compared among jaws, maturity stages, sexes and rows. Generalized linear models were used to determine the subset of measures that most contribute to explain the variability between groups. It was observed that males have longer teeth than females, but the teeth of females are wider. These differences are attributed to reproductive behaviour, in which males bite females to hold them during copulation. This study provides a description of the teeth of A. doellojuradoi, supplying a valuable tool for identification of species. In addition, the establishment of the main variations observed in the dentition, improves the understanding of the species' biology. © 2017 The Fisheries Society of the British Isles.
Full Text Available Environmental DNA (eDNA techniques have only recently been applied in the marine environment to detect the presence of marine species. Species-specific primers and probes were designed to detect the eDNA of the endangered Maugean skate (Zearaja maugeana from as little as 1 L of water collected at depth (10-15 m in Macquarie Harbour (MH, Tasmania. The identity of the eDNA was confirmed as Z. maugeana by sequencing the qPCR products and aligning these with the target sequence for a 100% match. This result has validated the use of this eDNA technique for detecting a rare species, Z. maugeana, in the wild. Being able to investigate the presence, and possibly the abundance, of Z. maugeana in MH and Bathurst harbour (BH, would be addressing a conservation imperative for the endangered Z. maugeana. For future application of this technique in the field, the rate of decay was determined for Z. maugeana eDNA under ambient dissolved oxygen (DO levels (55% saturation and lower DO (20% saturation levels, revealing that the eDNA can be detected for 4 and 16 hours respectively, after which eDNA concentration drops below the detection threshold of the assay. With the rate of decay being influenced by starting eDNA concentrations, it is recommended that samples be filtered as soon as possible after collection to minimize further loss of eDNA prior to and during sample processing.
Li, Weidong; Chen, Xiao; Liu, Wenai; Sun, Renjie; Zhou, Haolang
The complete mitochondrial genome of the Yellow-spotted skate Okamejei hollandi was determined in this study. It is 16,974 bp in length and contains 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and one putative control region. The overall base composition is 30.5% A, 27.8% C, 14.0% G, and 27.8% T. There are 28 bp short intergenic spaces located in 12 gene junctions and 31 bp overlaps located in nine gene junctions in the whole mitogenome. Two start codons (ATG and GTG) and two stop codons (TAG and TAA/T) were used in the protein-coding genes. The lengths of 22 tRNA genes range from 68 (tRNA-Ser2) to 75 (tRNA-Leu1) bp. The origin of L-strand replication (OL) sequence (37 bp) was identified between the tRNA-Asn and tRNA-Cys genes. The control region is 1311 bp in length with high A + T and poor G content.
Colonello, J C; García, M L; Lasta, C A; Menni, R C
This study provides information on the reproduction of spotback skate Atlantoraja castelnaui. A total of 232 individuals (119 females and 113 males) were obtained from surveys carried out between 2003 and 2006, from the south-west Atlantic Ocean, between 34 and 42° S and <50 m deep; another 514 specimens (241 females and 273 males) were obtained between 2005 and 2007 from commercial fishery operations carried out in the same area and landings in the port of Mar del Plata, Argentina. Males ranged from 185 to 1250 mm total length (L(T) ) and females from 243 to 1368 mm L(T) . Length at maturity was estimated to be 980 mm for males and 1089 mm L(T) for females. Lack of variation of testis mass together with the continuous production of mature spermatocyst and spermatozoa in deferent ducts suggested that males can reproduce throughout the year. Females reproduced year-round with peaks of reproductive activity an integral part of a continuous cycle. This conclusion is corroborated by the seasonal variation of ovaries, oviducal gland and the occurrence of females with eggs in the uterus throughout the year. Results from this study indicate that A. castelnaui is very susceptible to fishery pressure. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.
Jeong, Dageum; Lee, Youn-Ho
The complete sequence of mitochondrial DNA of a longnose skate, Raja rhina was determined for the first time. It is 16,910 bp in length containing 2 rRNA, 22 tRNA and 13 protein coding genes with the same gene order and structure as those of other Rajidae species. The nucleotide of L-strand is composed of 30.1% A, 27.2% C, 28.5% T and 14.2% G, showing a slight A + T bias. The G is the least used base and markedly lower at the third codon position (5.4%). Twelve of the 13 protein coding genes use ATG as their start codon while the COX1 starts with GTG. As for stop codon, only ND4 shows incomplete stop codon TA. This mitogenome is the first report for a species of the genus Raja, and providing a valuable resource of genetic information for understanding the phylogenetic relationship and the evolution of the genus Raja as well as the family, Rajidae.
Weltz, Kay; Lyle, Jeremy M; Ovenden, Jennifer; Morgan, Jessica A T; Moreno, David A; Semmens, Jayson M
Environmental DNA (eDNA) techniques have only recently been applied in the marine environment to detect the presence of marine species. Species-specific primers and probes were designed to detect the eDNA of the endangered Maugean skate (Zearaja maugeana) from as little as 1 L of water collected at depth (10-15 m) in Macquarie Harbour (MH), Tasmania. The identity of the eDNA was confirmed as Z. maugeana by sequencing the qPCR products and aligning these with the target sequence for a 100% match. This result has validated the use of this eDNA technique for detecting a rare species, Z. maugeana, in the wild. Being able to investigate the presence, and possibly the abundance, of Z. maugeana in MH and Bathurst harbour (BH), would be addressing a conservation imperative for the endangered Z. maugeana. For future application of this technique in the field, the rate of decay was determined for Z. maugeana eDNA under ambient dissolved oxygen (DO) levels (55% saturation) and lower DO (20% saturation) levels, revealing that the eDNA can be detected for 4 and 16 hours respectively, after which eDNA concentration drops below the detection threshold of the assay. With the rate of decay being influenced by starting eDNA concentrations, it is recommended that samples be filtered as soon as possible after collection to minimize further loss of eDNA prior to and during sample processing.
Jeong, Dageum; Lee, Youn-Ho
The complete sequence of mitochondrial DNA of a Yellownose skate, Zearaja chilensis was determined for the first time. It is 16,909 bp in length covering 2 rRNA, 22 tRNA and 13 protein coding genes with the identical gene order and structure as those of other Rajidae species. The nucleotide of L-strand is composed of low G (14.3%), and slightly high A + T (58.9%) nucleotides. The strong codon usage bias against the use of G (6.0%) is found at the third codon positions. Twelve of the 13 protein coding genes use ATG as the start codon while COX1 starts with GTG. As for the stop codon, only ND4 shows an incomplete stop codon TA. This is the first report of the mitogenome for a species in the genus Zearaja, providing a valuable source of genetic information on the evolution of the family Rajidae and the genus Zearaja as well as for establishment of a sustainble fishery management plan of the species.
Jeong, Dageum; Kim, Sung; Kim, Choong-Gon; Lee, Youn-Ho
The complete mitochondrial genome of the Korean skate, Hongeo koreana, the sole member of its genus, is investigated for the first time. The genome consists of 16,906 bp in length including 2 rRNA, 22 tRNA and 13 protein coding genes with the same gene order and structure of the genome as those of other Rajidae species. The overall nucleotide composition of the L-strand is A = 29.8%, C = 27.9%, T = 27.9% and G = 14.3%, showing a high A + T bias. The anti-G bias (6.0%) is more significant in the third codon position. Twelve of the 13 protein-coding genes use ATG as their start codon while the COX1 gene starts with GTG. For stop codon, ND3 and ND4 genes show incomplete stop codon T. The mitogenome sequence of H. koreana will provide important information on the evolution and the phylogenetic relation of the genus Hongeo in relation to the other genera of the family Rajidae.
Jeong, Dageum; Kim, Sung; Kim, Choong-Gon; Lee, Youn-Ho
The complete sequence of mitochondrial DNA of a Kwangtung skate, Dipturus kwangtungensis, was determined as being circular molecules of 16,912 bp including 2 rRNA, 22 tRNA, 13 protein coding genes (PCGs) and a control region. The arrangement of the PCGs is the same as that found in other Rajidae species. The nucleotide of L-strand which encodes most of the proteins is composed of 30.2% A, 27.4% C, 28.2% T and 14.2% G with a bias toward A+T slightly. Twelve of 13 PCGs are initiated by the ATG codon while COX1 starts with GTG. Only ND4 harbors the incomplete termination codon, TA. All tRNA genes have a typical clover-leaf structure of mitochondrial tRNA with the exception of tRNA(Ser)AGY, which has a reduced DHU arm. This mitogenome is the first report for a species of the genus Dipturus, which will become an important source of information on the phylogenetic relationship and the evolution of the genus Dipturus within the family Rajidae.
Last, Peter R; Weigmann, Simon; Dumale, Don
Molecular analyses and information gleaned from an examination of the newly available adult male of the North-West Pacific skate, Okamejei jensenae Last & Lim, supported earlier concerns that the species might be mis-assigned. Morphological data based on this specimen supported its placement in a new genus Orbiraja that is assigned to the recently named Rostrorajini based on molecular evidence. This subgroup of the family Rajidae also includes Malacoraja, Neoraja, Rostroraja and an unresolved 'amphi-American Assemblage' (sensu McEachran & Dunn, 1998). Orbiraja is unique within the rajids in having the combination of three, very closely spaced median thorn rows on the tail, no dark-edged ventral pores, and a clasper skeleton with a prominent accessory terminal 3 cartilage formed by a medio-distal extension of the accessory terminal 2 cartilage. Its spiracle appears to be situated posteriorly with respect to the orbit. The group contains two other nominal species, Orbiraja powelli (Alcock) and O. philipi (Lloyd), and an un-named species from Indonesia that needs further investigation. Orbiraja jensenae is rediagnosed based on characteristics of the adult male.
Moreira, Renan A; Gomes, Ulisses L; de Carvalho, Marcelo R
Claspers of adult specimens of the skate tribe Riorajini, family Arhynchobatidae, comprising Atlantoraja and Rioraja, are described, compared, and systematically reinterpreted based on material collected off southeastern and southern Brazil. For the first time the external components and musculature of the clasper of members of this tribe are described and related to internal (skeletal) structures. The component pecten is present in all species of Atlantoraja but absent in Rioraja. The new external component grip, an autapomorphy of A. cyclophora fully developed in adults, is described. Rioraja presents dorsal terminals 1 and 2, ventral marginal distally extended and ventral terminal cartilages. Dorsal terminals 1 and 2, ventral marginal distally extended, accessory terminals 2 and 3, and ventral terminal cartilages occur in Atlantoraja. A new interpretation of the ventral marginal distally extended is discussed. The dorsal terminal 1 of Atlantoraja has an inverted U shape but is triangular in Rioraja. The accessory terminal 2 cartilage is reported for the first time in Atlantoraja cyclophora. The accessory terminal 3 is present only in A. platana and A. cyclophora, and absent in Rioraja and A. castelnaui. Many of our findings concerning the clasper skeleton do not agree with previous interpretations. The arrangement, distribution and systematic significance of many of the terminal clasper components are discussed among rajoids. © 2017 Wiley Periodicals, Inc.
Jeong, Dageum; Kim, Sung; Kim, Choong-Gon; Myoung, Jung-Goo; Lee, Youn-Ho
The complete sequence of mitochondrial DNA of a mottled skate, Raja pulchra was sequenced as being circular molecules of 16,907 bp including 2 rRNA, 22 tRNA, 13 protein-coding genes (PCGs), and an AT-rich control region. The organization of the PCGs is the same as those found in other Rajidae species. The nucleotide of L-strand is composed of 29.8% A, 28.0% C, 27.9% T, and 14.3% G with a bias toward A + T slightly. Twelve of 13 PCGs are initiated by the ATG codon while COX1 starts with GTG. Only ND4 harbors the incomplete termination codon, TA. All tRNA genes have a typical clover-leaf structure of mitochondrial tRNA with the exception of [Formula: see text] which has a reduced DHU arm. This mitogenome will provide essential information for better phylogenetic resolution and precision of the family Rajidae and the genus Raja as well as for establishment of a fish stock recovery plan of the species.
Kolinski, John M; Mandre, Shreyas; Brenner, Michael P; Weitz, David A; Mahadevan, L
Drops impacting on a surface are ubiquitous in our everyday experience. This impact is understood within a commonly accepted hydrodynamic picture: it is initiated by a rapid shock and a subsequent ejection of a sheet leading to beautiful splashing patterns. However, this picture ignores the essential role of the air that is trapped between the impacting drop and the surface. Here we describe a new imaging modality that is sensitive to the behavior right at the surface. We show that a very thin film of air, only a few tens of nanometers thick, remains trapped between the falling drop and the surface as the drop spreads. The thin film of air serves to lubricate the drop enabling the fluid to skate on the air film laterally outward at surprisingly high velocities, consistent with theoretical predictions. Eventually this thin film of air must break down as the fluid wets the surface. We suggest that this occurs in a spinodal-like fashion, and causes a very rapid spreading of a wetting front outwards; simultaneous...
Haug, William B; Drinkwater, Eric J; Cicero, Nicholas J; Barthell, J Anthony; Chapman, Dale W
This investigation sought to determine the effects of dry-land sprint start training on short track speed skating (STSS) start performance. Nine highly trained short track athletes completed a control period of normal STSS training followed by a four-week training intervention. Before and after the control and intervention periods, athletes performed three electronically timed dry-land and on-ice 14.43 m maximal sprint start efforts. The intervention consisted of two sprint sessions per week consisting of nine electronically timed 14.43 m dry-land sprint starts in addition to normal STSS training. The control period resulted in no substantial change in on-ice start performance (Mean Δ: -0.01 s, 95% Confidence Limits (CL): -0.08 to 0.05 s; Effect Size (ES): -0.05; Trivial) however, a small change was observed in dry-land start performance (Mean Δ: -0.07 s, 95% CL: -0.13 to -0.02 s; ES: -0.49). Following brief specific dry-land sprint start training a small improvement was observed in both on-ice (Mean Δ: -0.07 s, 95% CL: -0.13 to -0.01 s; ES: -0.33) and dry-land (Mean Δ: -0.04 s, 95% CL: -0.09 to 0.00 s; ES: -0.29) start performance. This investigation suggests STSS start performance can be improved through a brief dry-land sprint start training program.
1 Abstract Title: Analysis of sports agents activities in connection with identifying and developing sports talents (on the examples of football and ice hockey). Objectives: The goals of this study was to analyze the activities of sports agents in ice hockey and football. The actual research was conducted by comparing the information from 4 groups of probands - a) Sports agents, b) Coaches, c) sports managers, d) players. Methods: The main research methor chosen was a qualitative research app...
Clark, J. Michio; Post, Andrew; Hoshizaki, Thomas Blaine; Gilchrist, M. D.
Helmets have successfully decreased the incidence of traumatic brain injuries (TBI) in ice hockey, yet the incidence of concussions has essentially remained unchanged. Current ice hockey helmet certification standards use peak linear acceleration as the principal measuring helmet performance, however peak linear acceleration may not be an appropriate variable to evaluate risk at all magnitudes of brain injury. The purpose of this study is to determine the relationship between linear accelerat...
Raibulov S. P.
Full Text Available The paper presents the results of justifying the use of thorny skate in the technology of minced meat canned products of special purpose. The key criterion determined the specialized purpose of canned food is the high content of physiologically functional food ingredient of chondroitin sulfate in the cartilage of thorny skate wings. The high content of chondroitin sulfate in raw materials ensures that the content of the physiologically functional ingredient in the finished canned food will be at the level from 220 to 250 mg per 100 g of product. The method of IR blanching is presented for removing urea from the thorny skate muscle tissue. To confirm the efficiency of the developed method of urea removal, it has been proposed to use a modified photocolorimetric method for determination of mass fractions of urea in feed flour according to the governmental standard GOST R 50032–92 "Feed flour made of fish, marine mammals, crustaceans and invertebrates. Methods of determining the mass fraction of urea and calculation of the crude protein with a given mass fraction of carbamide". With the help of this technique, the efficiency of urea removal from the thorny skate tissue by the proposed method has been determined. The residual urea content in the meat of thorny skate after IR blanching is 0.76 %, which is two times lesser than border value of sensitivity of the person (approximated as 1.2 %. The paper presents the materials of experimental substantiation of optimum formulation of new canned meat based on the method of fuzzy modeling. The ratio of the main components of the meatballs recipe (thorny skate and Atlantic cod close to the optimum is 48 % by weight of meat for each component separately.
Full Text Available The aim of this study was to investigate whether a sports vision training program improves the visual performance of youth male field hockey players, ages 12 to 16 years, after an intervention of six weeks compared to a control group with no specific sports vision training. The choice reaction time task at the D2 board (Learning Task I, the functional field of view task (Learning Task II and the multiple object tracking (MOT task (Transfer Task were assessed before and after the intervention and again six weeks after the second test. Analyzes showed significant differences between the two groups for the choice reaction time task at the D2 board and the functional field of view task, with significant improvements for the intervention group and none for the control group. For the transfer task, we could not find statistically significant improvements for either group. The results of this study are discussed in terms of theoretical and practical implications
Tuff, Taylor; Chrobak, Karen
Septic bursitis (SB) is an important differential diagnosis in athletes presenting with an acute subcutaneous swelling of the elbow or knee. Prompt recognition is essential to minimize recovery time and prevent the spread of infection. Due to the significant overlap in clinical features, it is often difficult to differentiate SB from non-septic bursitis (NSB) without bursal aspirate analysis. SB is commonly not considered unless the bursitis is accompanied by a local skin lesion or fever. This study describes two cases of septic olecranon bursitis and one case of septic prepatellar bursitis in adult hockey players presenting to a sports medicine clinic. None of the cases presented with an observable skin lesion and only one case developed a fever. It is therefore essential that clinicians maintain a high index of suspicion and monitor for signs of progression when presented with an acute bursitis even in the absence of these features.
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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.
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
Full Text Available Purpose: to study the factor structure of technical and tactical actions of hockey players of high qualification of different playing line of business. Material and methods: for the leadthrough of analysis of competition activity information of technical and tactical actions of hockey players was used NHL. Competition activity was in general complication analysed more than 800 hockey players of different line of business. Methods were used: pedagogical supervisions and analysis of competition activity, analysis of data of the special scientific-methodical literature, an analysis of data is the Internet, methods of mathematical statistics. Results: information is presented in relation to the specific of competition activity of hockey players of high class of different line of business in a match. The factor structure of technical and tactical activity of hockey players, executing in the command of function of extreme forward, central forward, defender and goalkeeper is set. for the players of line of attack most meaningfulness was had factors, related to the attack of gate of competitor, for defenders are power single combats, defense of gate and selection of puck, for a goalkeeper the most meaningful factor is characterized by efficiency of reflection of throws on a gate. Conclusions: the exposed features are in realization of technical and tactical actions the hockey players of high class of different playing line of business, it is necessary certainly to take into account in the process of estimation and control.
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; Menon, Ravi S
To determine whether multiparametric MRI data can provide insight into the acute and long-lasting neuronal sequelae after a concussion in adolescent athletes. 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. 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. 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. Copyright © 2017 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.
Emerson, Dawn M; Torres-McGehee, Toni M; Emerson, Charles C; LaSalle, Teri L
Despite exercising in cool environments, ice hockey players exhibit several dehydration risk factors. Individualized fluid plans (IFPs) are designed to mitigate dehydration by matching an individual's sweat loss in order to optimize physiological systems and performance. A randomized control trial was used to examine IFP versus ad libitum fluid ingestion on hydration in 11 male minor professional ice hockey players (mean age = 24.4 ± 2.6 years, height = 183.0 ± 4.6 cm, weight = 92.9 ± 7.8 kg). Following baseline measures over 2 practices, participants were randomly assigned to either control (CON) or intervention (INT) for 10 additional practices. CON participants were provided water and/or carbohydrate electrolyte beverage to drink ad libitum. INT participants were instructed to consume water and an electrolyte-enhanced carbohydrate electrolyte beverage to match sweat and sodium losses. Urine specific gravity, urine color, and percent body mass change characterized hydration status. Total fluid consumed during practice was assessed. INT consumed significantly more fluid than CON (1180.8 ± 579.0 ml vs. 788.6 ± 399.7 ml, p = 0.002). However, CON participants replaced only 25.4 ± 12.9% of their fluid needs and INT 35.8 ± 17.5%. Mean percent body mass loss was not significantly different between groups and overall indicated minimal dehydration (hydration status. Based on urine measures, both methods were unsuccessful in preventing dehydration during practice, suggesting practice-only hydration is inadequate to maintain euhydration in this population when beginning hypohydrated.
Kriz, Peter K; Stein, Cynthia; Kent, Janet; Ruggieri, Danielle; Dolan, Emilie; O'Brien, Michael; Meehan, William P
To investigate the association between physical maturity and risk of prolonged concussion symptoms in adolescent ice hockey players. Prospective cohort study of 145 patients ages 13-18 years with concussion referred to 3 hospital-affiliated sports medicine clinics between September 1, 2012 and March 31, 2015. Concussion evaluations included Post Concussive Symptom Score, neurologic examination, and postinjury computerized neurocognitive testing. Pubertal development at initial visit was assessed by the Pubertal Developmental Scale. Duration of concussion symptoms (days) was the main outcome. Statistical comparisons were conducted using Student t test, Wilcoxon rank sum, and logistic regression. Mean symptom duration was 44.5 ± 48.7 days. Nearly one-half (48.3%) of all players enrolled had prolonged concussion symptoms (≥ 28 days); most (86.9%) had symptom resolution by 90 days. Among males, less physically mature adolescents took longer to recover than more physically mature players (54.5 days vs 33.4 days; P = .004). "Early" Pubertal Category Score was the strongest predictor of prolonged symptoms (OR = 4.29, 95% CI 1.24-14.85; P = .021) among males. Among females, heavier weight increased the odds of experiencing prolonged symptoms (OR 1.07, 95% CI 1.00-1.14; P = .039). Among adolescent ice hockey players, early-pubertal stage is independently associated with longer recovery from concussion in males, and heavier weight is associated with longer concussion recovery in females. Until further studies determine valid physical maturity indicators, peripubertal collision sport athletes should compete in leagues grouped by relative age and be discouraged from "playing up" on varsity teams. Copyright © 2016 Elsevier Inc. All rights reserved.
Kuhn, Andrew W; Zuckerman, Scott L; Totten, Douglas; Solomon, Gary S
Few studies have empirically examined outcomes of concussion in the National Hockey League (NHL) and whether these athletes return to games after concussion at a performance level comparable to preconcussion play. NHL players would not demonstrate changes in performance or style of play after returning from a concussion when compared with a group of control athletes. Cohort study; Level of evidence, 3. NHL players with a reported hockey-related concussion during the 2008-2009 through 2014-2015 seasons were identified utilizing secondary media sources. Players who missed games for non-injury related causes were selected as the control group. "Performance" was operationally defined as the statistics for goals, assists, points, plus-minus, and shots, and "style of play" was operationally defined as the statistics for penalty minutes, blocked shots, hits, giveaways, and time on ice. Each gameplay statistic was recorded and totaled for the 5 games before and after each player's injury or absence. After meeting strict inclusion criteria, the 2 groups were compared across each postconcussion/absence statistic by generalized linear models while incorporating the particular preconcussion/absence statistic, position played, games missed, and concussion history as covariates to control for intraplayer and between-group differences. A total of 287 players sustained a concussion; 130 missed time for non-injury related reasons and were identified as controls. After the exclusion criteria were applied, 94 concussed players were compared with 58 controls. None of the models reached statistical significance, indicating that the concussion and control groups did not differ across performance or style of play after returning from a concussion or non-injury related absence. When compared with a control group, players who returned to consistent play after concussion did not demonstrate changes in performance or style of play. © 2016 The Author(s).
Bruner, Mark W; Boardley, Ian D; Allan, Veronica; Root, Zach; Buckham, Sara; Forrest, Chris; Côté, Jean
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 (Mage = 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.
Full Text Available Robert Micieli,1 Jonathan A Micieli21Faculty of Science and Engineering, York University, 2Department of Ophthalmology and Vision Science, University of Toronto, Toronto, ON, CanadaAbstract: Eye, orbital, and facial injuries are significant risks to National Hockey League (NHL players, and can be mitigated by the use of a partial visor – currently optional for all non-rookie players. The goal of the current study was to determine the overall use of visors among non-rookie NHL players in the 2013–2014 season and assess factors influencing their uptake. This was an observational, cross-sectional study using active NHL rosters and demographic information obtained from the official NHL website. Visor use was determined based on in-game video or images at two different time points in the 2013–2014 season. The use of visors during the 2013–2014 season was 75.2% among non-rookie players. When rookies were included, the overall use of visors was 77.8%. Compared to Canadian-born players, European players were significantly more likely to choose to wear a visor (odds ratio [OR] 3.48, 95% confidence interval [CI] 1.96–6.17. Players in the younger age-groups, particularly those younger than 24 years (OR 5.67, 95% CI 2.52–5.76 and those between 24 and 28 years (OR 2.18, 95% CI 1.23–3.87, were more likely to wear a visor compared to older players. Overall, visor use continues to grow in the NHL independently of new legislation, and is more likely in younger players and those of European origin.Keywords: ice hockey, facial protection, professional sports, eye injuries, safety
McKay, Carly D; Tufts, Raymond J; Shaffer, Benjamin; Meeuwisse, Willem H
There is a paucity of literature examining injury and illness rates in men's professional ice hockey. This study aimed to determine injury and illness rates in the NHL over six seasons, and identify predictors of injury-related time loss in this population. This study involved an inclusive cohort of hockey players from all NHL teams competing in the 2006-2007 through 2011-2012 seasons. A standardised electronic injury surveillance system was used to report injury and illness events. The primary outcome was regular season and postseason time-loss injury/illness. The secondary outcome was man-games lost from the competition. On the basis of the estimated athlete exposures (AEs), the overall regular season incidence density was 15.6 injuries/1000 AEs and 0.7 illnesses/1000 AEs. Based on recorded time on ice, the injury rates were roughly threefold higher at 49.4 injuries/1000 player game-hours and 2.4 illnesses/1000 player game-hours. There was a reduction in injury rates over the 6-year period, with the greatest reduction between the 2007-2008 and 2008-2009 seasons. Multivariate predictors of time loss greater than 10 days were being a goalie (OR=1.68, 95% CI 1.18 to 2.38), being injured in a road game (OR=1.43, 95% CI 1.25 to 1.63) and the mechanism of injury being a body check (OR=2.21, 95% CI 1.86 to 2.62). There was an overall reduction in the time-loss injury and illness rates over six seasons. Being a goaltender, being injured on the road and being injured by a body check were the risk factors for time loss greater than five 'man games'.
Cristina López de Subijana Hernández
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.
Prokop, Neal W; Duncan, Lindsay R; Andersen, Ross E
Collegiate athletes often use nutritional programs and supplements to elicit body composition changes in muscle or fat. It is unknown if athletes can accurately perceive their fluctuations in body composition, yet their understanding may help them make more accurate interpretations regarding the success of potential nutrition or exercise regimens. The purpose of this study was to investigate if collegiate hockey players could accurately perceive a change in body composition during a 3-month period within their regular season, in which no predetermined nutritional or exercise program was provided. Twenty-four male Canadian collegiate hockey players completed preseason and midseason body composition assessments using dual-energy X-ray absorptiometry. Immediately before the midseason scan, players attempted to accurately match their perceived fluctuation in composition, with predetermined categorical ranges of relative body composition and strength. Two-thirds of players and one-half of players accurately perceived changes in arm-lean and arm-fat tissue, respectively. Approximately two-thirds of players did not accurately perceive gains or losses of lean or fat tissue within their leg and overall body. Although some athletes partially detected changes in the lean and fat tissue of particular regions, the vast majority of players cannot detect the type, or amount of tissue gained and lost across the overall body. Body composition assessments, rather than an athlete's perceptions, should be used to help interpret the success of a sport nutrition or exercise program. Athletes should be aware that physiologic adaptations might take place unnoticed, which could affect the acceptance and adherence of nutrition or exercise interventions.
Vescovi, Jason D; Frayne, Devon H
To examine locomotor demands and metabolic-power characteristics of National Collegiate Athletic Association (NCAA) field hockey matches. Using a cross-sectional design, global positioning system (GPS) technology tracked Division I field hockey players from 6 teams during 1 regular-season match (68 player observations). An ANOVA compared locomotor demands and metabolic-power characteristics among positions. Paired t tests compared dependent variables between halves. Defenders played 5-6 min more than midfielders, whereas midfielders played 6-7 min more than forwards. Defenders covered less relative distance (98 m/min) than forwards and midfielders (110-111 m/min), as well as more low-intensity running than forwards and less high-intensity running than midfielders. Lower mean metabolic power (9.3 W/kg) was observed for defenders than forwards and midfielders (10.4 W/kg). There was no difference in playing time between halves; however, all 3 positions had a reduction in relative distance (7-9%) and mean metabolic power (8-9%) during the second half. Despite more playing time, defenders covered less relative distance and had lower mean metabolic power than other positions. Moderate-intensity, high-intensity, and sprint distance were similar between positions, highlighting the greater relative demands on forwards because they tended to have the least amount of playing time. The reduction of key metrics during the second half was similar among positions and warrants further investigation. These initial results can be used to design position-specific drills or create small-sided games that replicate match demands for NCAA athletes, thus helping establish strategies for developing physiological ability of players at this level.
Kniffin, Kevin M; Howley, Thomas; Bardreau, Cole
Kniffin, KM, Howley, T, and Bardreau, C. Putting muscle into sports analytics: strength, conditioning, and ice hockey performance. J Strength Cond Res 31(12): 3253-3259, 2017-Sports analytics is best known as the field of research that focuses on discovering slight but significant improvements within competitions; however, broader sets of athlete- and team-level data from outside competitions (e.g., strength and conditioning metrics) have been typically left out from such analyses. Given that strength and conditioning programs are perhaps the most common avenue through which people expect extra-competition progress to translate into within-competition performance, it is clear that strength and conditioning metrics warrant closer analytic attention. To illustrate this approach, we present a study of National Collegiate Athletic Association (NCAA) Division 1 Men's Ice Hockey players that integrates both (a) strength and conditioning metrics and (b) in-game performance measurements. Bivariate analyses show a significant positive correlation between bench press performance and points scored (r = 0.15), although multivariate analyses point to positive relationships between strength and conditioning measures and playing time as the more important finding. Although within-competition data are increasingly accessible for analytics research, the basic approach that we develop highlights the importance of considering extra-competition variables such as strength and conditioning metrics for understanding both coaching decisions regarding playing time and within-competition performance. We also discuss ways in which the integrated approach that we present offers potential applications for strength and conditioning professionals as well as players, coaches, and team managers.
Hänninen, Timo; Parkkari, Jari; Tuominen, Markku; Iverson, Grant L; Öhman, Juha; Vartiainen, Matti; Luoto, Teemu M
To examine test-retest reliability of the SCAT3 for two consecutive seasons using a large sample of professional male ice hockey players, and to make recommendations for interpreting change on the test. A cross-sectional descriptive study. Preseason baseline testing was administered in the beginning of the seasons 2013-2014 and 2014-2015 to 179 professional male hockey players in rink side settings. The test-retest reliabilities of the SCAT3 components were uniformly low. However, the majority of athletes remained grossly within their own individual performance range when two pre-season SCAT3 baseline scores were compared to published normative reference values. Being tested by the same person or a different person did not influence the results. It was uncommon for the Symptom score to worsen by ≥3 points, the Symptom Severity score to worsen by ≥5 points, SAC total score to worsen by ≥3 points, M-BESS total error points to increase by ≥3, or the time to complete Tandem Gait to increase by ≥4s; each occurred in less than 10% of the sample. The SCAT3 has low test-retest reliability. Change scores should be interpreted with caution, and more research is needed to determine the clinical usefulness of the SCAT3 for diagnosing concussion and monitoring recovery. Careful examination of the natural distributions of difference scores provides clinicians with useful information on how to interpret change on the test. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Kluczynski, Melissa A; Kang, Jeansol V; Marzo, John M; Bisson, Leslie J
The prevalence of comorbid knee pathology has been examined for sports-related anterior cruciate ligament (ACL) injuries, but it has not been examined in ice hockey players. To compare concomitant bone bruising, collateral ligament injuries, and intra-articular injuries in ACL injuries suffered during ice hockey versus other sports. Cross-sectional study; Level of evidence, 3. A total of 20 patients with ACL injuries sustained during ice hockey were identified from a prospective registry, of which 95% were male and 90% had a contact mechanism of injury (MOI). Thirteen cases and 46 controls who sustained ACL injuries from ice hockey and other sports, respectively, were included. Inclusion criteria for cases and controls were male sex, contact MOI, no prior knee surgery, magnetic resonance imaging (MRI) within 6 weeks of injury, and surgery within 3 months of injury. Age, body mass index (BMI), MRI findings (bone bruising, medial and lateral collateral ligament [MCL, LCL] injuries), and arthroscopic findings (meniscus tears, chondral injuries) were compared for cases versus controls using t tests or exact chi-square tests. Age (22.9 ± 8.8 vs 23.4 ± 10.4 years, P = .88) and BMI ≥25 kg/m(2) (50% vs 65.9%, P = .66) did not differ between cases and controls. Cases had less lateral bone bruising (lateral femoral condyle: 54.6% vs 93%, P = .01; lateral tibial plateau: 72.7% vs 93%, P = .09) and no medial bone bruising (medial femoral condyle: 0% vs 7%, P = .06; medial tibial plateau: 0% vs 32.6%, P = .05) compared with controls. Cases had less frequent lateral meniscus tears than controls (23.1% vs 58.5%, P = .05). There were no significant differences in MCL (40% vs 31.2%, P = .77), LCL (0% vs 3.9%, P > .999), medial meniscus tears (7.7% vs 37%, P = .08), and chondral injuries (10% vs 9.4%, P > .999) for cases versus controls. Male ice hockey players with ACL injuries had less lateral femoral condyle and medial tibial plateau bone bruising compared with other sports
Martinez, Christopher M; Rohlf, F James; Frisk, Michael G
Instances of sexual dimorphism occur in a great variety of forms and manifestations. Most skates (Batoidea: Rajoidei) display some level of body shape dimorphism in which the pectoral fins of mature males develop to create a distinct bell-shaped body not found in females. This particular form of dimorphism is present in each of the sister species Leucoraja erinacea and Leucoraja ocellata, but differences between sexes are much greater in the former. In order to understand the nature and potential causes of pectoral dimorphism, we used geometric morphometrics to investigate allometry of fin shape in L. erinacea and L. ocellata and its relationship to the development of reproductive organs, based on previous work on the bonnethead shark, Sphyrna tiburo. We found that allometric trajectories of overall pectoral shape were different in both species of skate, but only L. erinacea varied significantly with respect to endoskeleton development. Male maturation was characterized by a number of sex-specific morphological changes, which appeared concurrently in developmental timing with elongation of cartilage-supported claspers. We suggest that external sexual dimorphism of pectoral fins in skates is a byproduct of skeletal growth needed for clasper development. Further, the magnitude of male shape change appears to be linked to the differential life histories of species. This work reports for the first time that pectoral dimorphism is a persistent feature in rajoid fishes, occurring in varying degrees across several genera. Lastly, our results suggest that pectoral morphology may be useful as a relative indicator of reproductive strategy in some species. © 2016 Wiley Periodicals, Inc.
Yang, Lei; Naylor, Gavin J P
We determined the complete mitochondrial genome sequence (16,760 bp) of the peacock skate Pavoraja nitida using a long-PCR based next generation sequencing method. It has 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 1 control region in the typical vertebrate arrangement. Primers, protocols, and procedures used to obtain this mitogenome are provided. We anticipate that this approach will facilitate rapid collection of mitogenome sequences for studies on phylogenetic relationships, population genetics, and conservation of cartilaginous fishes.
Full Text Available Detailed descriptions of morphological features, morphometrics, neurocranium anatomy, clasper structure and egg case descriptions are provided for the thickbody skate Amblyraja frerichsi; a rare, deep-water species from Chile, Argentina and Falkland Islands. The species diagnosis is complemented from new observations and aspects such as colour, size and distribution are described. Geographic and bathymetric distributional ranges are discussed as relevant features of this taxońs biology. Additionally, the conservation status is assessed including bycatch records from Chilean fisheries.
Weinstein, S.; Becker, N. C.; Wang, D.; Fryer, G. J.
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.
LaVoi, Nicole M; Stellino, Megan Babkes
The authors examined achievement goal orientation (J. L. Duda & J. G. Nicholls, 1992), parental influence (M. L. Babkes & M. R. Weiss, 1999), and the parent-initiated motivational climate (S. A. White, 1996, 1998) in combination to broaden understanding of competitive male youth hockey players' (N = 259) perceptions of the parent-created sport climate and its relation to their self-reported good and poor sport behaviors (GPSB). Exploratory factor analysis revealed a multidimensional measure of GPSB. Multiple regression analyses indicated that athletes' GPSB were significantly predicted by different forms of parental influence. Canonical correlations revealed a complex picture of the contributions of goal orientation and the parent-created sport climate on boys' GPSB in youth hockey. Results expand knowledge of the influence that parents have in youth sport and emphasize the importance of understanding how children's interpretations of parental beliefs and behaviors affect their choices to engage in good and poor sport behaviors.
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.
Li, Jing Xian; Xu, Dong Qing; Hoshizaki, Blaine
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 dancing on proprioception may be associated with their movement characteristics.
Brunelle, J P; Goulet, C; Arguin, H
To reduce the number of transgressions to the rule, the occurrence of violent acts and to prevent injuries, Hockey Québec adopted the Fair-Play Program (FPP). The objective of the present study was to evaluate the effectiveness of the FPP. 52 Bantam (14-15 years) teams participated in this cohort study. In total, 49 games (13 with the FPP, 36 without FPP) were systematically assessed for transgressions to the rule. Body checking was allowed in all games. Transgressions to the rule data were obtained using a real time observation system in a natural setting, while injury data were collected through a self-administered questionnaire. Data were analysed using generalised linear models with generalised estimating equations accounting for potential team effect. The number of penalties per game was significantly lower (p hockey world promote fair play values. Moreover, this project clearly showed the importance of program evaluation and the value of direct observation in a natural setting.
Kroshus, Emily; Kubzansky, Laura D; Goldman, Roberta E; Austin, S Bryn
Many athletes fail to report concussion symptoms to coaches or medical personnel, putting them at risk for potentially catastrophic neurologic consequences if additional brain trauma is sustained prior to full recovery. The purpose of this study was to determine whether concussion reporting norms prior to the start of the athletic season predicted reporting symptoms of a possible concussion during the season, and whether this association was moderated by athletic identity. Members of six National Collegiate Athletic Association Division 1 men's ice hockey teams (n = 116) completed written surveys before and after the 2012-2013 collegiate ice hockey season. Participants who at pre-season perceived that "most athletes" were likely to report symptoms of a concussion were themselves more likely to report symptoms during the season. Athletic identity weakly moderated this association. Perceived reporting norms may be an important target of interventions aimed at reducing symptom under-reporting among athletes.