Physical fitness normative values for 6–18-year-old Greek boys and girls,using the empirical distribution and the lambda,mu, and sigma statistical method     

Konstantinos D. Tambalis  Demosthenes B. Panagiotakos  Glykeria Psarra  Stelios Daskalakis  Stavros A. Kavouras  Nickos Geladas 《European Journal of Sport Science》2016,16(6):736-746

The aim of the this study was to establish age- and gender-specific physical fitness normative values and to compare percentiles and Z scores values in a large, nationwide sample of Greek children aged 6–18 years. From March 2014 to May 2014, a total of 424,328 boys and girls aged 6–18 years who attended school in Greece were enrolled. The studied sample was representative, in terms of age–sex distribution and geographical region. Physical fitness tests (i.e. 20?m shuttle run test (SRT), standing long jump, sit and reach, sit-ups, and 10?×?5?m SRT) were performed and used to calculate normative values, using the percentiles of the empirical distributions and the lambda, mu, and sigma statistical method. Normative values were presented as tabulated percentiles for five health-related fitness tests based on a large data set comprising 424,328 test performances. Boys typically scored higher than girls on cardiovascular endurance, muscular strength, muscular endurance, and speed/agility, but lower on flexibility (all p values <0.001). Older boys and girls had better performances than younger ones (p?相似文献   

How much does lower body strength impact Paralympic running performance?     

E. M. Beckman  M. J. Connick  S. M. Tweedy 《European Journal of Sport Science》2016,16(6):669-676

Objectives: Development of evidence-based methods of Paralympic classification requires research quantifying the relative strength of association between ratio-scaled measures of impairment and athletic performance. The purpose of this study was to quantify the extent to which muscle strength affects running performance in runners with and without brain impairment. Design: Cross-sectional study. Methods: Participants were 41 male runners: 13 with brain impairments (RBI) and 28 non-disabled (NDR). All participants completed a maximal 60-m sprint and a novel battery of three lower limb isometric strength tests. Results: RBI showed significantly lower strength scores compared with NDR on the more affected side in leg flexion (176 vs. 243?N), leg extension (993 vs. 1661?N) and plantarflexion (824 vs. 1457?N). Significant differences were also seen on the less affected side in plantarflexion (1072 vs. 1508?N). RBI were significantly slower in the acceleration phase (0–15?m) (3.2?s?±?0.3?vs. 2.8?s?±?0.2) and top speed phase (30?60?m) (4.3?s?±?0.6?vs. 3.8?s?±?0.3). Correlation analysis showed stronger relationships between strength and running performance in RBI than NDR; however, the correlations were not significant. Conclusions: This study evaluated measures to assess strength for the purposes of classification and found that the measures were significantly different in RBI compared with NDR indicating the tests were able to capture strength impairment in this population. This study indicates that strength may be an important impairment type to assess in this population, as impairments of muscle strength may influence the outcome of running performance in athletes with more severe impairments.  相似文献   

Ground reaction forces of Olympic and World Championship race walkers     

Brian Hanley  Athanassios Bissas 《European Journal of Sport Science》2016,16(1):50-56

Race walking is an Olympic event where no visible loss of contact should occur and the knee must be straightened until midstance. The purpose of this study was to analyse ground reaction forces of world-class race walkers and associate them with key spatiotemporal variables. Nineteen athletes race walked along an indoor track and made contact with two force plates (1000 Hz) while being filmed using high-speed videography (100 Hz). Race walking speed was correlated with flight time (r = .46, p = .049) and flight distance (r = .69, p = .001). The knee's movement from hyperextension to flexion during late stance meant the vertical push-off force that followed midstance was smaller than the earlier loading peak (p < .001), resulting in a flattened profile. Athletes with narrower stride widths experienced reduced peak braking forces (r = .49, p = .046), peak propulsive forces (r = .54, p = .027), peak medial forces (r = .63, p = .007) and peak vertical push-off forces (r = .60, p = .011). Lower fluctuations in speed during stance were associated with higher stride frequencies (r = .69, p = .001), and highlighted the importance of avoiding too much braking in early stance. The flattened trajectory and consequential decrease in vertical propulsion might help the race walker avoid visible loss of contact (although non-visible flight times were useful in increasing stride length), while a narrow stride width was important in reducing peak forces in all three directions and could improve movement efficiency.  相似文献   

Talent identification and selection in elite youth football: An Australian context     

Donna O'Connor  Paul Larkin  A. Mark Williams 《European Journal of Sport Science》2016,16(7):837-844

We identified the perceptual–cognitive skills and player history variables that differentiate players selected or not selected into an elite youth football (i.e. soccer) programme in Australia. A sample of elite youth male football players (n?=?127) completed an adapted participation history questionnaire and video-based assessments of perceptual–cognitive skills. Following data collection, 22 of these players were offered a full-time scholarship for enrolment at an elite player residential programme. Participants selected for the scholarship programme recorded superior performance on the combined perceptual–cognitive skills tests compared to the non-selected group. There were no significant between group differences on the player history variables. Stepwise discriminant function analysis identified four predictor variables that resulted in the best categorization of selected and non-selected players (i.e. recent match-play performance, region, number of other sports participated, combined perceptual–cognitive performance). The effectiveness of the discriminant function is reflected by 93.7% of players being correctly classified, with the four variables accounting for 57.6% of the variance. Our discriminating model for selection may provide a greater understanding of the factors that influence elite youth talent selection and identification.  相似文献   

Effects of load mass carried in a backpack upon respiratory muscle fatigue     

Mark Faghy  Sam Blacker  Peter I. Brown 《European Journal of Sport Science》2016,16(8):1032-1038

Purpose: The purpose of this study was to investigate whether loads carried in a backpack, with a load mass ranging from 0 to 20?kg, causes respiratory muscle fatigue. Methods: Eight males performed four randomised load carriage (LC) trials comprising 60?min walking at 6.5?km?h^?1 wearing a backpack of either 0 (LC₀), 10 (LC₁₀), 15 (LC₁₅) or 20?kg (LC₂₀). Inspiratory (P_Imax) and expiratory (P_Emax) mouth pressures were assessed prior to and immediately following each trial. Pulmonary gas exchange, heart rate (HR), blood lactate and glucose concentration and perceptual responses were recorded during the first and final 60?s of each trial. Results: Group mean P_Imax and P_Emax were unchanged following 60-min load carriage in all conditions (p?>?.05). There was an increase over time in pulmonary gas exchange, HR and perceptions of effort relative to baseline measures during each trial (p?p?>?.05). Conclusions: These findings indicate that sub-maximal walking with no load or carrying 10, 15 or 20?kg in a backpack for up to 60?min does not cause respiratory muscle fatigue despite causing an increase in physiological, metabolic and perceptual parameters.  相似文献   

我院广告学系毕业设计指导刍议     

LI Dao-guo 《无锡教育学院学报》2007,(4)

从毕业设计选题、研究方法、研究原则等方面,阐述毕业设计教学要以问题研究为导向,面向事实本身,整合优化求知方式;以实战型策划、实证性研究为依托,从封闭式的单向度研究转向开放式的多向度研究,促进理论探索与广告实践相结合。同时,以创新教育为核心,拓展学生创造性研究能力,尊重创新研究的自主权,全面提升毕业设计质量。  相似文献   

Maximum Product,Even Less Process: Increasing Efficiencies in Archival Processing Using ArchivesSpace     

Kathryn Hujda  Amanda Wick 《Journal Of Archival Organization》2016,13(3-4):100-113

As the archival profession has adapted to new challenges and adopted modern practices like More Product, Less Process, the University of Minnesota has embraced these changes. Even so, implementing new practices can take time and effort. With the adoption of ArchivesSpace in 2016, the University found itself being fast-tracked to even more efficient methods for establishing physical and intellectual control over collections. This article will examine the case studies of two large collections that were in the midst of being processed when ArchivesSpace was implemented at the University of Minnesota. How did the switch to ArchivesSpace impact the processing of these collections, and how will these experiences impact the future of archival processing at the University?  相似文献   

全民健身工作的实践与思考     

周风祥  李向阳 《伊犁教育学院学报》2001,14(1):90-92

几年来，我国的全民健身事业，在各级政府领导的关怀和支持下，通过各界同仁的努力，取得了一定成效，全民健身活动的开展，不仅丰富了社会，家庭，个人的文化生活，而且促进了国民体质的增强。  相似文献   

浅谈生产实习与专业课和毕业设计的有机结合     

李宇鹏 《教学研究(河北)》2002,25(3):249-251

针对专业课学时少，内容多的矛盾，以及本科生毕业设计综合质量不稳定的情况，结合指导专业生产实习的累积的经验，提出把专业课的部分内容向生产实习移植，并在生产实习之前就把毕业设计题目落实到具体学生的观点。介绍了为实现专业课部分内容移植进行的一些探索和体会，阐述了让学生在专业生产实习中获取更多与毕业设计内容直接相关的感性知识的必要性。  相似文献   

绩效和财富：我国公司治理中的股价效应     

阳晓明 《四川师范大学学报(社会科学版)》2003,30(1):14-19

资本市场是公司外部治理机制的主导力量。股份水平既是管理绩效的显示，又具有巨大的财富效应。低估的股价可能引发代理权竞争和敌意接管。在我国，股价在公司治理中的约束机制和激励机制失效，其原因除了证券市场上股价形成机制的非理性因素外，更主要的原因在于我国公司治理结构中的先天性缺陷，其中关键是要解决公司股权结构中的国有股“一股独大”的问题。  相似文献