Validity of an upper-body-mounted accelerometer to measure peak vertical and resultant force during running and change-of-direction tasks

This study assessed the validity of a tri-axial accelerometer worn on the upper body to estimate peak forces during running and change-of-direction tasks. Seventeen participants completed four different running and change-of-direction tasks (0°, 45°, 90°, and 180°; five trials per condition). Peak crania-caudal and resultant acceleration was converted to force and compared against peak force plate ground reaction force (GRF) in two formats (raw and smoothed). The resultant smoothed (10 Hz) and crania-caudal raw (except 180°) accelerometer values were not significantly different to resultant and vertical GRF for all running and change-of-direction tasks, respectively. Resultant accelerometer measures showed no to strong significant correlations (r = 0.00–0.76) and moderate to large measurement errors (coefficient of variation [CV] = 11.7–23.9%). Crania-caudal accelerometer measures showed small to moderate correlations (r = ? 0.26 to 0.39) and moderate to large measurement errors (CV = 15.0–20.6%). Accelerometers, within integrated micro-technology tracking devices and worn on the upper body, can provide a relative measure of peak impact force experienced during running and two change-of-direction tasks (45° and 90°) provided that resultant smoothed values are used.     

A distributional analysis of the effect of physical exercise on a choice reaction time task

Abstract

The aim of this study was to examine the facilitating effects of physical exercise on the reaction process. Eleven participants with specific expertise in decision-making sports performed a choice reaction time task during moderate sub-maximal exercise (90% of their ventilatory threshold power). Participants were tested at rest and while cycling. During exercise, the participants were faster, without being more variable. We suggest that the effect of exercise on cognitive performance was due to a major generalized improvement of the whole distribution of response time and, although the benefit effect was small, it was consistent throughout the entire range of reaction times.     

日本终身学习体系构建的保障及其启示

上世纪70年代左右,终身教育和终身学习理念的相继提出给世界各国发展教育提供了新的视野。日本终身教育在四十多年发展过程中积累了丰富的理论和实践经验,走在了亚洲甚至是世界的前列。因此,探讨日本终身学习体系构建的保障,从法律法规体系、机构设施体系和财政投入体系三方面进行解析,对我国构建和发展终身教育有借鉴作用。     

System Analysis for Oxygen Uptake Kinetics with Step and Pseudorandom Binary Sequence Exercise in Endurance Athletes

We examined whether the system analysis for step and pseudorandom binary sequence (PRBS) exercises could be useful to characterize oxygen uptake (VO₂) kinetics of female sedentary subjects and endurance athletes. Breath-by-breath VO₂ was determined during step- and PRBS-cycle ergometer exercises. The time course of the VO₂ kinetics was evaluated by the time constant of the second phase, which should reflect the adjustment of the oxidative metabolism at the skeletal muscle level. The VO₂ kinetics were significantly faster in long-distance runners than in sedentary subjects for both exercises. A significant relationship was observed in the VO₂ kinetics obtained from step and PRBS exercises. In each group, there was no significant difference in the VO₂ kinetics for step and PRBS exercises. These results indicated that the system analysis with PRBS exercises revealed the faster VO₂ kinetics in endurance athletes than in sedentary subjects.     

如何把握经济责任审计中的校长负责制

“党委领导下的校长负责制”是当前法定的高校管理体制,校长、书记这两个高校的“一把手”都是高校领导干部经济责任审计的审计对象,审计内容的侧重、问题责任的区分是高校领导干部经济责任审计的难点。“党委领导下的校长负责制”的法定含义,是解决这一审计难点的有效途径。     

开放教育教学资源共建共享——以现实困境与路径机制为中心的探讨

＂开放与共享＂是开放教育的本质,＂开放与共享＂的关键在于优质教学资源的供给。需求与供给的不平衡成为开放教育发展中的障碍,也成为开放教育的现实困境。教学资源的共建共享成为开放教育发展的必然选择,如何突破现有困境,找出开放教育共建共享的合理路径机制,是开放教育切实可行的发展之道。     

关于改革沈阳大学平时成绩考评体系的思考

以提高平时成绩为目标,在分析了沈阳大学平时成绩考核的现状及存在的问题,即评定方法简单、计分依据单调、评定程序缺失的基础上,针对性地提出了强化平时成绩在学生总成绩核算中的地位,实现评定方法的多样化和计分标准的明细化,以及规范平时成绩的程序。     

基于CBR的网球技战术信息系统研究——以双手反拍为例

近年来,学者对网球运动技术的研究越来越多,但是对于网球技战术信息系统的研究和开发较少。本文通过对CBR应用于计算机辅助处置网球比赛中技战术运用行为的分析,设计了一个基于案例推理的网球技战术信息系统模型,即通过对案例库中记忆的网球技战术进行相似性搜索,在分析网球技战术实施方案的各项内容及实施后收到的效果的基础上,对目标行为的预案进行决策支持。     

中国体育制度之伤--《李元伟篮坛风云路》和《忠诚无悔：我与中国足球》的对比思考

通过对中国篮坛和足坛前掌门人李元伟与阎世铎的传记(《李元伟篮坛风云路》和《忠诚无悔：我与中国足球》)从上任与卸任、与媒体打交道、外教及执教环境以及危机处理4个方面的对比分析,得出以下结论：1)“民间传言+私露口风+正式委任”的任命机制,存在太多主观因素,从长远看不利于篮球、足球发展;2)“管办不分”一定程度上阻碍了篮、足球职业化改革进程;3)篮、足球管理仍以“人治”为主,缺乏“法制”根基。我国足球、篮球运动发展的不同轨迹表明,在改革中谋求发展,在发展中推进改革,是中国体育体制改革必由之路。     

阳光体育视野下高校体育课程价值取向及构建

本文通过分析我国关于开展阳关体育运动的有关规定和政策,在高校体育课程设置和建构过程中,从强调个体兴趣和需要的满足,以及人的自我实现的达成,进而实现有较强的个人倾向的、稳固的价值取向,为构建全面、综合、发展的体育课程结构模式和过程规范化、管理科学化的课程体系和评价体系提供一些参考,也为高校学生的身体健康和参与体育锻炼的提供一些指导。