Ice friction of flared ice hockey skate blades

In ice hockey, skating performance depends on the skill and physical conditioning of the players and on the characteristics of their equipment. CT Edge have recently designed a new skate blade that angles outward near the bottom of the blade. The objective of this study was to compare the frictional characteristics of three CT Edge blades (with blade angles of 4 degrees, 60, and 8 degrees, respectively) with the frictional characteristics of a standard skate blade. The friction coefficients of the blades were determined by measuring the deceleration of an aluminium test sled equipped with three test blades. The measurements were conducted with an initial sled speed of 1.8 m s(-1) and with a load of 53 kg on each blade. The friction coefficient of the standard blades was 0.0071 (s = 0.0005). For the CT Edge blades with blade angles of 4 degrees, 6 degrees, and 8 degrees, friction coefficients were lower by about 13%, 21%, and 22%, respectively. Furthermore, the friction coefficients decreased with increasing load. The results of this study show that widely accepted paradigms such as "thinner blades cause less friction" need to be revisited. New blade designs might also be able to reduce friction in speed skating, figure skating, bobsledding, and luge.     

Clap冰刀与传统冰刀蹬冰机制比较

通过对clap式冰刀与传统冰刀蹬冰机制的比较得出，clap式冰刀蹬冰技术原理体现在两个方面：一是通过提高踝关节的灵活性来改变下肢各关节的发力性质；二是通过冰刀结构的改变来揭示速滑蹬冰技术动作加速理论的适用条件。其核心是提高踝关节的灵活性。     

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

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

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

Ice hockey requires rapid transitions between skating trajectories to effectively navigate about the ice surface. Player performance relates in large part to effective change-of-direction manoeuvres, but little is known about how those skills are performed mechanically and the effect of equipment design on them. The purpose of this study was to observe the kinetics involved in those manoeuvres as well as to compare whether kinetic differences may result between two skate models of varying ankle mobility. Eight subjects with competitive ice hockey playing experience performed rapid lateral (90°) left and right change-of-direction manoeuvres. Kinetic data were collected using force strain gauge transducers on the blade holders of the skates. Significantly greater forces were applied by the outside skate (50–70% body weight, %BW) in comparison to the inside skate (12–24%BW, p < 0.05). Skate model and turn direction had no main effect, though significant mixed interactions between leg side (inside/outside) with skate model or turn direction (p < 0.05) were observed, with a trend for left-turn dominance. This study demonstrates the asymmetric dynamic behaviour inherent in skating change-of-direction tasks.     

Forecheck,backcheck, health check: the benefits of playing recreational ice hockey for adults in Canada

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.     

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

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

金属研磨平板消除冰刀卷刃的实验研究

研究目的：通过剖析传统研磨冰刀出现卷刃的原因及消除卷刃过程中存在的问题，寻求解决该问题的途径。研究方法：借鉴工业生产中金属研磨平板精研磨理论与实践，运用比较的方法，找出油石研磨冰刀存在的卷刃问题，确定出解决该问题的实验方案。主要结果和结论：设计制造出速滑刀金属研磨平板、勾刃冰刀金属研磨棒。通过实验证明，运用该方法、研磨冰刀刃间面可直接切断卷刃，获得良好的锋刃及滑度，取代传统油石研磨卷刃做法具有可行性。     

我国冰球运动发展对策探讨

分析制约我国冰球发展的相关因素,针对我国冰球运动发展中存在的问题,提出了促进我国冰球运动发展的对策。     

中国冰球运动60年发展历程的回顾、审视与展望

运用文献资料法、分析法、比较研究法对新中国成立以来冰球运动发展的60年历程分阶段进行回顾与分析,总结了冰球发展历经的＂初兴＂、＂曲折＂、＂恢复＂、＂黄金＂、＂衰落＂几个阶段,并指出了现阶段冰球运动发展的问题所在,在此基础上对中国冰球未来发展进行了积极规划与展望。     

Whole-body predictors of wrist shot accuracy in ice hockey: a kinematic analysis

The purpose of this study was to identify joint angular kinematics that corresponds to shooting accuracy in the stationary ice hockey wrist shot. Twenty-four subjects participated in this study, each performing 10 successful shots on four shooting targets. An eight-camera infra-red motion capture system (240 Hz), along with passive reflective markers, was used to record motion of the joints, hockey stick, and puck throughout the performance of the wrist shot. A multiple regression analysis was carried out to examine whole-body kinematic variables with accuracy scores as the dependent variable. Significant accuracy predictors were identified in the lower limbs, torso and upper limbs. Interpretation of the kinematics suggests that characteristics such as a better stability of the base of support, momentum cancellation, proper trunk orientation and a more dynamic control of the lead arm throughout the wrist shot movement are presented as predictors for the accuracy outcome. These findings are substantial as they not only provide a framework for further analysis of motor control strategies using tools for accurate projection of objects, but more tangibly they may provide a comprehensive evidence-based guide to coaches and athletes for planned training to improve performance.     

Assessment of ice hockey performance in real-game conditions

Abstract

The aim of this study was to adapt a performance measurement tool, the Team Sport Assessment Procedure (TSAP), to ice hockey during match-play. In addition to the six categories included in the original observational procedure, the ice hockey TSAP contained four new categories. Twelve Pee-Wee ice hockey matches were video-recorded during a regional championship tournament. The game play of 103 of the 11- to 12-year-old players was then analysed on video by three trained observers, based on all 10 ice hockey TSAP categories. The observational data were thereafter used to compute, for each player, a “volume of play per minute” and an efficiency index. Finally, volume of play per minute and the efficiency index were combined to obtain a composite score, the TSAP performance score. Additional measurements for each player were playing time during the observed matches, coaches’ assessments (dominant, good, less decisive), and player tournament statistics (number of points, based on assists and goals). The mean TSAP performance score was substantially higher for players rated by their coaches as dominant and for players who accumulated more than one tournament point, findings that provide evidence of the validity of the TSAP measure. In inter-observer reliability analyses of TSAP observational data provided by the trained observersfrom video recordings, the level of agreement between each pair of observers was 80–82%. Reliability correlations over a series of three matches (r=0.26, 0.59, and 0.16 respectively) showed that the TSAP performance score was relatively unstable. Ice hockey coaches may use this adapted Team Sport Assessment Procedure to better understand the offensive implication of each player in a given match, since the 10 observational variables provide more extensive information on performance than traditional statistical measures. Due to low performance stability of the TSAP performance score, coaches ought to use the observational assessment data for the formative rather than the summative assessment of their players unless they cumulate information over a series of several matches. Formative assessment can be conducted either during training camps or even during the regular season.     

冰球“自动结束处罚”规则的运用

冰球比赛新规则中对比赛中在队员犯规后的处理上和解除的顺序等方面都有很大的变化,这对冰球运动的技战术发展有着重要的影响,促进着训练方法与手段的改进,并对运动员的技战术的全面性提出更高的要求。通过查阅相关文献,对“自动结束处罚”的概念进行剖析,并采用归纳法将其分成6种类型,并结合实例对每种类型进行深入研究,为教练员、运动员和裁判员能切实把握规则变化的实质,改进训练工作和裁判工作,提供理论依据与参考。     

冰球赛事对齐齐哈尔城市影响及发展研究

运用文献资料法、逻辑分析法,研究冰球赛事对齐齐哈尔的城市影响,针对冰球赛事在齐齐哈尔的发展形势,提出相应的冰球赛事发展策略,旨在推动齐齐哈尔市冰球体育赛事开展的同时,依托冰球赛事提升齐齐哈尔城市形象,促进城市发展。     

从2014年世界女子冰球锦标赛看中国女冰现状

通过对2014年世界女子冰球锦标赛B组各队比赛成绩、技战术进行统计,对目前中国女子冰球队的状态进行分析,深刻总结训练和比赛中存在的问题。中国女冰在技战术的综合能力上与世界强队相比具有较大差距,尤其是在攻区抢断、回追阻截、射门得分、防守反击等方面的问题较为突出。提出加强个人技战术的培养,结合比赛提高对抗能力,培养多变的战术体系,形成自己的技战术风格等对策和建议,旨在提高女冰的技战术水平,对中国女冰重返世界强队取得冬奥会参赛资格显得尤为重要。     

Specific muscle synergies in national elite female ice hockey players in response to unexpected external perturbation

This study aimed to investigate specific muscle synergies in elite ice hockey players indicating highly developed postural control strategies used to restore balance against unexpected external perturbations. Seven elite athletes (EA) on the women’s national ice hockey team and 7 non-athletes (NA) participated in this study. Based on trajectories of centre of mass (COM), analysis periods were divided into an initial phase (a balance disturbance after perturbation onset) and a reversal phase (a balance recovery response), respectively. Muscle synergies were extracted at each phase by using non-negative matrix factorization. k-means cluster analysis was performed to arrange similar muscle synergies in all participants. EA showed significantly shorter recovery period of COM and smaller body sway than NA. In the initial phase, we identified 2 EA-specific synergies related to ankle plantar flexors or neck extensors. In the case of an NA-specific synergy, co-activation of the ankle plantar flexors and dorsiflexors was found. In the reversal phase, no specific muscle synergies were identified. As the results, EA-specific muscle synergies showed low co-activation strategy of agonists and antagonists in ankle and neck extensors. Our results could provide critical information for rehabilitation strategies in athletes requiring high postural stability.     

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

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

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

Abstract

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 the players at the end of the first season was 14.2 years (s = 1.1). Repeated-measures analyses of covariance, with standard of performance and measurement occasion as factors and age as a covariate, showed that the elite players fared better than the sub-elite players on technical and tactical variables. Female elite youth players also scored better on interval endurance capacity, motivation, and confidence. Future elite players appear to have excellent tactical skills by the age of 14. They also have good specific technical skills and develop these together with interval endurance capacity better than sub-elite youth players in the subsequent 2 years. To verify our conclusions, we will be tracking these players into adulthood.     

Relation between multidimensional performance characteristics and level of performance in talented youth field hockey players

To determine the relationship between multidimensional performance characteristics and level of performance in talented youth field hockey players, elite youth players (n = 38, mean age 13.2 years, s = 1.26) were compared with sub-elite youth players (n = 88, mean age 14.2 years, s = 1.26) on anthropometric, physiological, technical, tactical and psychological characteristics. Multivariate analyses with performance level and gender as factors, and age as the covariate, showed that the elite youth players scored better than the sub-elite youth players on technical (dribble performance in a peak and repeated shuttle run), tactical (general tactics; tactics for possession and non-possession of the ball) and psychological variables (motivation) (P <?0.05). The most discriminating variables were tactics for possession of the ball, motivation and performance in a slalom dribble. Age discriminated between the two groups, indicating that the elite youth players were younger than the sub-elite players. In the guidance of young talented players to the top as well as in the detection of talented players, more attention has to be paid to tactical qualities, motivation and specific technical skills.     

Optimization of handheld gauge sizes for rocker measurements of skate blades and bobsleigh runners

This work uses numerical methods to investigate the feasibility of modifying an instrument used in speed skating to analyze blades from four different ice sports. The instrument, a handheld rocker gauge, is adapted to create a device that can effectively profile other types of skate blades and bobsleigh runners. Since there are significant differences between short and long-track blades one could expect a difference in the gauges used to study these blades. Despite this expectation, the same gauge is used in both disciplines. The usefulness of these gauges has been proven in speed skating so it is expected that they should also be useful to study hockey blades and bobsleigh runners. To optimize the gauge size for different blade types we digitize the profile of a blade, which we use to simulate gauge data. Then we use that gauge data to reconstruct the profile and compare it to the original digital profile. The result is compared for various gauge sizes and the gauge size is optimized for each of the four disciplines. The only commercially available device seems optimal for bobsleigh and long track speed skating. Smaller gauges are recommended for analyzing short track speed skates and hockey skates.