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

Jaymee R. Shell  Shawn M. K. Robbins  Philippe C. Dixon  Philippe J. Renaud  René A. Turcotte  Tom Wu 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(3):313-324

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.  相似文献   

The comparative advantage of international education: Different places, different lenses, different voices     

Simon McGrath 《International Journal of Educational Development》2012,32(1):1-2

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Effect of gear ratio on peak power and time to peak power in BMX cyclists     

Lee P. Rylands  Simon J. Roberts  Howard T. Hurst 《European Journal of Sport Science》2017,17(2):127-131

The aim of this study was to ascertain if gear ratio selection would have an effect on peak power and time to peak power production in elite Bicycle Motocross (BMX) cyclists. Eight male elite BMX riders volunteered for the study. Each rider performed three, 10-s maximal sprints on an Olympic standard indoor BMX track. The riders’ bicycles were fitted with a portable SRM power meter. Each rider performed the three sprints using gear ratios of 41/16, 43/16 and 45/16 tooth. The results from the 41/16 and 45/16 gear ratios were compared to the current standard 43/16 gear ratio. Statistically, significant differences were found between the gear ratios for peak power (F(2,14)?=?6.448; p?=?.010) and peak torque (F(2,14)?=?4.777; p?=?.026), but no significant difference was found for time to peak power (F(2,14)?=?0.200; p?=?.821). When comparing gear ratios, the results showed a 45/16 gear ratio elicited the highest peak power,1658?±?221?W, compared to 1436?±?129?W and 1380?±?56?W, for the 43/16 and 41/16 ratios, respectively. The time to peak power showed a 41/16 tooth gear ratio attained peak power in ?0.01?s and a 45/16 in 0.22?s compared to the 43/16. The findings of this study suggest that gear ratio choice has a significant effect on peak power production, though time to peak power output is not significantly affected. Therefore, selecting a higher gear ratio results in riders attaining higher power outputs without reducing their start time.  相似文献   

Annual review of work in newspaper and periodical history 1996–1998     

Diana Dixon 《Media History》2013,19(2):201-221

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Altering the “Inner Life of the Culture”: Monstrous Memory and the Persistence of 9/11     

Roger I. Simon 《Review of Education, Pedagogy & Cultural Studies》2013,35(3-4):352-374

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Education in small states: policies and priorities     

Simon McGrath 《比较教育学》2014,50(4):509-510

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The role of fantasy figures in the regulation of young children's behavior: Santa Claus,the Easter Bunny,and donations     

David J. Dixon  Harry L. Hom 《Contemporary educational psychology》1984,9(1):14-18

The present study examined the influence of Santa Claus and the Easter Bunny on children's donations near the Easter season. Kindergarten and first-grade children were asked to tell stories about Santa Claus, the Easter Bunny, or pets, for which they received nine pieces of gum. They were then encouraged to donate any amount of their gum to handicapped children. Main effects were found only for grade, with first-grade children donating significantly more than kindergarten children. In addition, a significant interaction was obtained between grade and type of story elicited from the child. This interaction revealed that for kindergarten children, the type of story failed to influence donations, whereas for first-grade children, stories referring to Santa Claus increased donations relative to stories told about the Easter Bunny or pets.  相似文献   

Effect of verbal instructions and image size on visual search strategies in basketball free throw shooting     

Al-Abood SA  Bennett SJ  Hernandez FM  Ashford D  Davids K 《Journal of sports sciences》2002,20(3):271-278

We assessed the effects on basketball free throw performance of two types of verbal directions with an external attentional focus. Novices (n = 16) were pre-tested on free throw performance and assigned to two groups of similar ability (n = 8 in each). Both groups received verbal instructions with an external focus on either movement dynamics (movement form) or movement effects (e.g. ball trajectory relative to basket). The participants also observed a skilled model performing the task on either a small or large screen monitor, to ascertain the effects of visual presentation mode on task performance. After observation of six videotaped trials, all participants were given a post-test. Visual search patterns were monitored during observation and cross-referenced with performance on the pre- and post-test. Group effects were noted for verbal instructions and image size on visual search strategies and free throw performance. The 'movement effects' group saw a significant improvement in outcome scores between the pre-test and post-test. These results supported evidence that this group spent more viewing time on information outside the body than the 'movement dynamics' group. Image size affected both groups equally with more fixations of shorter duration when viewing the small screen. The results support the benefits of instructions when observing a model with an external focus on movement effects, not dynamics.  相似文献   

Visual search and biological motion perception in tennis   总被引：1，自引：0，他引：1  

Ward P  Williams AM  Bennett SJ 《Research quarterly for exercise and sport》2002,73(1):107-112

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A quiver full of arrows: recommended Web-based tutorials for PubMed,PowerPoint, Ovid MEDLINE,and FrontPage     

Dixon LA 《Medical reference services quarterly》2002,21(2):55-64

Librarians often are responsible for instructing their patrons in the use of various databases and popular software packages. When this instruction can't be provided through face-to-face contact, Web-based tutorials can be useful tools to bridge the information gap. This article recommends Web-based tutorials for PubMed, Ovid MEDLINE, PowerPoint, and FrontPage.  相似文献