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   

Imagen especular e imagen antiespecular     

René Zazzo 《Infancia y Aprendizaje》2013,36(6):77-82

RESUMEN

Para afirmarse como sujeto el niño debe ser capaz de percibirse como objeto. El reconocimiento del otro precede a la identificación de sí mismo. La imagen de sí mismo en el espejo se identifica antes de que el niño se reconozca en foto o en filme. Hacia los 2,5 años se produce este reconocimiento en foto o en filme sin ambigüedad, mientras que la identificación de la imagen especular continúa siendo “frágil”, posiblemente debido a la perplejidad o incertidumbre que suscita. A partir de la observación de las reacciones de niños ante un espejo y en un video de sí mismos, se investiga cómo y cuándo el niño construye su propia imagen. Hasta el tercer año de vida, la reacción del niño ante la imagen especular es como si viera a otro niño, dándose intercambios sociales. La reacción de perplejidad desaparece cuando se consigue la plena apropiación de la imagen.  相似文献   

Can we dispense with mimesis in representation?     

José A. Díez 《Metascience》2012,21(1):105-110

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Multimedia and Training: Practice and Skills of European Producers,Results of the European Project ‘START‐UP’ (Part 2)     

Christine Gardiol Gutierrez  André Boder 《Educational Media International》2013,50(3):196-200

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Heather E. Douglas: Science, Policy, and the Value-Free Ideal     

José Luis Luján 《Science & Education》2013,22(4):873-875

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Conflict as a catalyst for learning     

Rashné R. Jehangir 《About Campus》2012,17(2):2-8

Rashné R. Jehangir challenges her students and herself to engage with tough issues like class, race, gender, disability, and homophobia. How does she help them learn from, and even embrace, the confict that inevitably arises? Read on to find out.  相似文献   

Effect of a Brazilian Jiu-jitsu-simulated tournament on strength parameters and perceptual responses     

Daniele Detanico  Rodolfo André Dellagrana  Marina Saldanha da Silva Athayde  Rafael Lima Kons  Angel Góes 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(1):115-126

This study aimed to analyse the effects of a simulated Brazilian jiu-jitsu (BJJ) tournament on vertical jump performance, grip strength test and perceived effort responses. 22 male BJJ athletes participated in a simulated tournament consisting of three 7 min matches separated by 14 min of rest. Kimono grip strength test (KGST), counter movement jump (CMJ) and rate of perceived exertion (RPE) were measured before and after each match, while RPE of specific areas was assessed after three matches. ANOVA for repeated measures was used to compare strength parameters after each match with the level of significance set at 5%. The key results showed a significant decrease of jump height (p = 0.001) and net vertical impulse in the CMJ (p = 0.031), as well as a reduction of the number of reps in the KGST (p < 0.001). A significant increase of RPE was found throughout the matches (p < 0.001). Considering the RPE in specific areas, no differences were observed between the upper and lower body (p = 0.743). We conclude that the BJJ simulated tournament generated a decrease of performance in both upper and lower limbs and provoked a progressive increase in the effort perception over the matches.  相似文献   

The Adoption of the Compact Disk Player: An Event History Analysis for the Netherlands     

Harrie Hansman  Clara H. Mulder  René Verhoeff 《Journal of Cultural Economics》1999,23(3):221-232

The compact disk (CD) player was one of the major audio innovations of the 1980s in the Netherlands. For studies of the temporal and social diffusion pattern of the CD player and the compact disks, both cultural and economic theories about innovations and music consumption are available. In this paper, these theories are combined in six working hypotheses concerning earlier adoption. The empirical analysis includes both time-invariant and time-varying variables and consumer characteristics. Event history analysis, the technique used in this article, enables one to incorporate these kinds of variables simultaneously in a dynamic model. Compared with the diffusion models usually employed by means of longitudinal analysis, event history analysis is a significant improvement in studying the development of the CD market in the Netherlands.  相似文献   

Learning from the experts: practice activities of expert decision makers in sport   总被引：3，自引：0，他引：3  

Baker J  Côté J  Abernethy B 《Research quarterly for exercise and sport》2003,74(3):342-347

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Un inventaire des notions impliquées dans un enseignement général de mathématique à l'école secondaire     

Théo Bernet  André Delessert 《Educational Studies in Mathematics》1972,4(4):450-465

Sans résumé  相似文献