Comparing the magnitude and direction of asymmetry during the squat,countermovement and drop jump tests in elite youth female soccer players     

Chris Bishop  Lucas A. Pereira  Valter P. Reis  Paul Read  Anthony N. Turner  Irineu Loturco 《Journal of sports sciences》2020,38(11-12):1296-1303

ABSTRACT

The aims of the present study were to provide an in-depth comparison of inter-limb asymmetry and determine how consistently asymmetry favours the same limb during different vertical jump tests. Eighteen elite female under-17 soccer players conducted unilateral squat jumps (SJ), countermovement jumps (CMJ) and drop jumps (DJ) on a portable force platform, with jump height, peak force, concentric impulse and peak power as common metrics across tests. For the magnitude of asymmetry, concentric impulse was significantly greater during the SJ test compared to CMJ (p = 0.019) and DJ (p = 0.003). No other significant differences in magnitude were present. For the direction of asymmetry, Kappa coefficients revealed fair to substantial levels of agreement between the SJ and CMJ (Kappa = 0.35 to 0.61) tests, but only slight to fair levels of agreement between the SJ and DJ (Kappa = ?0.26 to 0.18) and CMJ and DJ (Kappa = ?0.13 to 0.26) tests. These results highlight that the mean asymmetry value may be a poor indicator of true variability of between-limb differences in healthy athletes. The direction of asymmetry may provide a useful monitoring tool for practitioners in healthy athletes, when no obvious between-limb deficit exists.  相似文献   

False-performance feedback does not affect punching forces and pacing of elite boxers     

Israel Halperin  Dale W. Chapman  Kevin G. Thompson  Chris Abbiss 《Journal of sports sciences》2019,37(1):59-66

Prior research indicates that providing participants with positive augmented feedback tends to enhance motor learning and performance, whereas the opposite occurs with negative feedback. However, the majority of studies were conducted with untrained participants performing unfamiliar motor tasks and so it remains unclear if elite athletes completing familiar tasks respond in a similar fashion. Thus, this study investigated the effects of three different versions of false-performance feedback on punching force (N), pacing (force over time) and ratings of perceived exertion (RPE) in 15 elite amateur male boxers. Athletes completed a simulated boxing bout consisting of three rounds with 84 maximal effort punches delivered to a punching integrator on four separate days. Day one was a familiarisation session in which no feedback was provided. In the following three days athletes randomly received false-positive, false-negative and false-neutral feedback on their punching performance between each round. No statistical or meaningful differences were observed in punching forces, pacing or RPE between conditions (P > 0.05; ≤ 2%). These null results could stem from the elite status of the athletes involved, the focus on performance rather than learning, or they may indicate that false feedback has a less potent effect on performance than previously thought.  相似文献   

The morning after the millennium: building the long-haul learning university     

Chris Duke 《International Journal of Lifelong Education》2013,32(1):24-36

Lifelong learning remains a powerful and valid concept important for the evolution of higher education and the university in the changing context of globalization, 30 years after its first popularization around 1970. Like the related concept of the learning society, it suffers trivializing fashion and reductionism. As we move into a phase of universal tertiary education, it is all the more necessary to understand how to enable universities to become learning organizations playing a distinct role in a fast-changing world. Enterprise is an essential associated characteristic, rather than a betrayal of the essentially academic. Universities need to function as open systems, building partnerships and sharing networks in and beyond their localities, and playing leading roles in the creation of learning regions and in new modes of knowledge protection. A grasp of these issues points the way for universities to survive as valued and unique social institutions adapted to and playing an active part in the making of knowledge societies.  相似文献   

Does Bradford's Law of Scattering predict the size of the literature in Cochrane Reviews?     

Charlotte E Nash-Stewart  Lisa M Kruesi  Chris B Del Mar 《Journal of the Medical Library Association》2012,100(2):135-138

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A Publisher Perspective: How One Publisher is Responding to the Changing World of Scholarly Communication     

Jayne Marks  Chris Bulock 《期刊图书馆员》2016,70(1-4):7-13

For this talk, Marks was tasked with summarizing the important trends in scholarly publishing in 45 minutes. The speaker reflected on the rapid changes that have occurred in journal publishing, which followed more than 300 years of relatively slow progress. Marks discussed key technology trends such as data curation, Open Access (OA) mandates, and the changes occurring in the global landscape of scholarly communications and library budgets. Wolters Kluwer Health has been responding to these trends with new publishing experiments including a Platinum OA model in emerging markets. Marks discussed the ways that publishers and libraries need to alter their traditional practices and instill a focus on their customers and communities.  相似文献   

Tier-specific evolution of match performance characteristics in the English Premier League: it’s getting tougher at the top     

Paul S. Bradley  David T. Archer  Bob Hogg  Gabor Schuth  Michael Bush  Chris Carling 《Journal of sports sciences》2016,34(10):980-987

This study investigated the evolution of physical and technical performances in the English Premier League (EPL), with special reference to league ranking. Match performance observations (n = 14,700) were collected using a multiple-camera computerised tracking system across seven consecutive EPL seasons (2006–07 to 2012–13). Final league rankings were classified into Tiers: (A) 1st–4th ranking (n = 2519), (B) 5th–8th ranking (n = 2965), (C) 9th–14th ranking (n = 4448) and (D) 15th–20th ranking (n = 4768). Teams in Tier B demonstrated moderate increases in high-intensity running distance while in ball possession from the 2006–07 to 2012–13 season (P < 0.001; effect size [ES]: 0.68), with Tiers A, C and D producing less pronounced increases across the same period (P < 0.005; ES: 0.26, 0.41 and 0.33, respectively). Large increases in sprint distance were observed from the 2006–07 to 2012–13 season for Tier B (P < 0.001; ES: 1.21), while only moderate increases were evident for Tiers A, C and D (P < 0.001; ES: 0.75, 0.97 and 0.84, respectively). Tier B demonstrated large increases in the number of passes performed and received in 2012–13 compared to 2006–07 (P < 0.001; ES: 1.32–1.53) with small-to-moderate increases in Tier A (P < 0.001; ES: 0.30–0.38), Tier C (P < 0.001; ES: 0.46–0.54) and Tier D (P < 0.001; ES: 0.69–0.87). The demarcation line between 4th (bottom of Tier A) and 5th ranking (top of Tier B) in the 2006–07 season was 8 points, but this decreased to just a single point in the 2012–13 season. The data demonstrate that physical and technical performances have evolved more in Tier B than any other Tier in the EPL and could indicate a narrowing of the performance gap between the top two Tiers.  相似文献   

Optical engineering for children – a structured approach     

John McCarthy  R. A. Moore 《European Journal of Engineering Education》2006,31(6):741-746

The present paper focuses on the application of a structured template, maximum impact flow (MIF), in order to encourage young students in the area of optics and optical engineering. MIF introduces a template in terms of individual steps and linked functionality and is shown to fuse separate learning tools together into a cohesive unit. Prioritization and teaching structures are also discussed with the promotion of technology identified as a key factor.  相似文献   

Pupils’ Perceptions of Technology in the Secondary School Curriculum: a case study     

Alun C. McCarthy  Dennis Moss 《Educational studies》1990,16(3):207-216

This paper reports a study of pupils attitudes to Craft Design Technology (CDT), Technology (GCSE) and Technology A level in a Mid Glamorgan secondary school. Technology is regarded by the pupils as being intellectually demandng and having a high ‘employment value’. This seems to attract more able pupils (of both sexes) than would be the case for other CDT subject areas. Pupils perceive CDT: Technology to have the characteristics of Science subjects rather than those of Arts or Crafts. A significant proportion of female students in this case study are attracted to study A level Technology and investigations are continuing to identify the underlying reasons for this.  相似文献   

Editorial     

Chris Curran 《European Journal of Education》2001,36(2):109-112

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Critical pedagogy,ecoliteracy & planetary crisis: the ecopedagogy movement     

Chris Francis 《Environmental Education Research》2011,17(5):705-708

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