健身气功八段锦功法初探

针对当今社会人们在学习、生活、工作等方面压力越来越大、无法长期坚持体育锻炼而造成体质下降等现象,本文向大家介绍八段锦健身气功新功法,旨在为大家缓解压力、解除疲劳、促进身心健康提供一些参考。     

Health-related fitness knowledge growth in middle school years: Individual- and school-level correlates

BackgroundHealth-related fitness knowledge (HRFK) has been an essential concept for many health and physical education programs. There has been limited understanding and longitudinal investigation on HRFK growth. This longitudinal study examined HRFK growth and its individual- and school-level correlates in middle school years under 1 curriculum condition: Five for Life.MethodsParticipants were 12,044 students from 47 middle schools. Data were collected at both individual/participant and school/institution levels. Individual-level variables included gender, grade, and HRFK test scores. School-level variables included percentage of students receiving free and reduced meals (FARM), student-to-faculty ratio for physical education, and school academic performance (SAP). We used hierarchical linear modeling to examine HRFK 3-year growth in relation to individual- and school-level correlates.ResultsThe average HRFK score at 6th grade for females was 42.81% ± 1.32%. The predicted HRFK growth was 17.06% ± 1.02% per year, holding other factors constant. A 1-standard deviation increase in FARM correlated with a 14.68%-point decrease in predicted test score (p = 0.02). A 1-standard deviation increase in SAP was associated with an 11.90%-point increase in HRFK score. Males had a significantly lower growth rate than females during the middle school years (0.78%/year, p = 0.02).ConclusionThe result showed that both individual- and school-level variables such as gender, FARM, and SAP influenced HRFK growth. Educators should heed gender differences in growth curves and recognize the correlates of school-level variables.     

Validity and reliability of a low-cost dynamometer to assess maximal isometric strength of upper limb

Muscle imbalance and deficit are key parameters for guiding rehabilitation and sports sessions and avoiding injuries. However, the high cost and non-portable nature of most instruments employed for muscle strength assessment frequently hamper an affordable evaluation in field conditions. This study evaluated the validity and reliability of a low-cost digital dynamometer to assess the maximal isometric strength of upper limb muscles. Fourteen physically active volunteers performed the main movements of the upper limb at maximal isometric strength: flexion-extension, internal-external rotation and abduction-adduction of the shoulder; and flexion-extension of both elbow and wrist. Validity was examined by comparing the strength values from the low-cost digital dynamometer and those measured by an isokinetic dynamometer, assumed as the gold standard. The correlation between both devices was perfect (r > 0.913), while Bland-Altman plots showed absolute agreement between both devices, the maximum range of the values of bias was ?0.99–1.00 N in wrist extension. Inter-tester and intra-tester reliability were excellent for all movements (ICC ≥ 0.855). The low-cost digital dynamometer showed strong validity and excellent reliability in assessing maximal isometric strength during the main movements of the upper limb. Professionals may use it for an affordable isometric muscle strength assessment in field situations.     

Static and dynamic accuracy of a magnetic-inertial measurement unit used to provide racket swing kinematics

Magnetic-inertial measurement units (MIMUs) are becoming more prevalent in sports biomechanics and may be a viable tool to evaluate kinematic parameters. This study examined the accuracy of a MIMU to estimate orientation angles under static conditions and dynamically from a squash racket during a forehand drive shot. A MIMU was mounted onto a goniometer and moved through 0–90°, with static data collected at 10° increments during 10 repetitions of all three axes. Typical error analyses showed the MIMU to be very reliable (TE ≤ 0.03°). MIMU accuracy was determined via intraclass correlation coefficients (ICC) (r > 0.999, p < 0.001). An ordinary least products regression showed no proportional bias and minimal fixed bias for all axes. Dynamic accuracy was assessed by comparing MIMU and optical motion capture data of squash racket swing kinematics. A MIMU was fixed onto a racket and 10 participants each hit 10 forehand shots. Mean orientation angle error at ball impact was <0.50° and ICC showed very high correlations (r ≥ 0.988, p < 0.001) for all orientations. Swing phase root mean squared errors were ≤2.20°. These results indicate that a MIMU could be used to accurately and reliably estimate selected racket swing kinematics.     

建设体育强国背景下体育经济重要地位及其发展策略

加快体育强国建设已成为一项国策,研究如何提高和建设可持续发展性的体育产业经济以解决人民日益增长的美好体育生活需要和不平衡不充分的发展之间的矛盾对建设体育强国具有重要意义。采用哲学辩证理论分析体育产业经济对体育强国构建的重要性,统计分析目前我国体育产业经济发展现状及其与发达国家的差距,结合十九大新时代背景下给出未来体育产业经济发展策略以期寻求为构建体育强国给出一些指导意见。认为：体育经济是体育强国的重要基石;开展全民健身运动、优化体育产业结构、政府政策导向市场化、跨产业融合增加与其他产业的结合度对构建体育强国具有重要的意义。     

Temporal trends in 6-minute walking distance for older Japanese adults between 1998 and 2017

BackgroundThe 6-minute walking distance (6MWD) is an excellent measure of both functional endurance and health. The primary aim of this study was to estimate temporal trends in 6MWD for older Japanese adults between 1998 and 2017; the secondary aim was to estimate concurrent trends in body size (i.e., height and mass) and self-reported participation in exercise/sport.MethodsAdults aged 65–79 years were included. Annual nationally representative 6MWD data (n = 103,505) for the entire period were obtained from the Japanese Ministry of Education, Culture, Sports, Science and Technology. Temporal trends in means (and relative frequencies) were estimated at the gender–age level by best-fitting sample-weighted linear/polynomial regression models, with national trends estimated by a post-stratified population-weighting procedure. Temporal trends in distributional variability were estimated as the ratio of coefficients of variation.ResultsBetween 1998 and 2017 there was a steady, moderate improvement in mean 6MWD (absolute = 45 m (95% confidence interval (95%CI): 43–47); percent = 8.0% (95%CI: 7.6%–8.4%); effect size = 0.51 (95%CI: 0.48–0.54)). Gender- and age-related temporal differences in means were negligible. Variability in 6MWD declined substantially (ratio of coefficients of variation = 0.89, 95%CI: 0.87–0.92), with declines larger for women compared to men, and for 75–79-year-olds compared to 65–74-year-olds. Correspondingly, there were moderate and negligible increases in mean height and mass, respectively, and negligible increases in the percentage who participated in exercise/sport at least 3 days per week and at least 30 min per session.ConclusionThere has been a steady, moderate improvement in mean 6MWD for older Japanese adults since 1998, which is suggestive of corresponding improvements in both functional endurance and health. The substantial decline in variability indicates that the temporal improvement in mean 6MWD was not uniform across the distribution. Trends in 6MWD are probably influenced by corresponding trends in body size and/or participation in exercise/sport.     

模拟智能BIT测试微处理机系统板

机内测试技术(Built-inTest,简称BIT)是一种能显著改善装备或系统测试性与诊断能力的重要技术手段。智能机内测试模拟系统是运用智能BIT技术的理论,开发出的一个对硬件设备在线测试的模拟系统。它是在Windows操作系统下,利用嵌入式C语言开发出来的,嵌入式C语言现广泛应用于各种硬件测试及开发环境中。智能机内测试模拟系统在对智能的模拟方面运用数组、随机函数等方法来实现,从而体现出智能机内测试的特点。本文描述了系统中对微处理机系统板部分的测试过程。     

经典测量理论与项目反应理论的比较研究

文章通过对经典测量理论和项目反应理论的模型及其假设、主要概念和参数、测量水平等方面进行比较,廓清了两种理论的联系和区别,明确了两种理论的优势和不足,从而为研究者根据测验实践的要求和各个理论的适用条件选择恰当的分析框架提供思路。     

不同年龄段女子足球运动员 Yo － Yo间歇恢复性测试与有氧、无氧能力的关联研究

本研究以中国国家女子足球队 U －12、U －15、U －19集训队伍的52名运动员为实验对象,分别进行了 Yo － Yo IR1、Yo － Yo IR2、最大摄氧量、平均无氧功率测试,以分析 Yo － Yo 间歇恢复性测试与不同年龄段女子足球运动员有氧、无氧能力的关系。相关性分析表明：（1）U －12年龄组女子足球运动员 Yo － Yo IR1、Yo － Yo IR2测试与最大摄氧量测试结果之间低度相关,而与平均无氧功率结果间呈高度相关;（2）U －15年龄组运动员 Yo － Yo IR1、Yo － Yo IR2和平均无氧功率结果间中度相关,而2者和运动员的最大摄氧量没有明显的相关关系;（3）U －19年龄组运动员 Yo － Yo IR1、Yo － Yo IR2测试成绩和最大摄氧量结果间显著相关,而与平均无氧功率间关联程度很弱。结论：Yo － Yo间歇恢复性测试可较好地评价处于青春期女子足球运动员的无氧能力,以及成年女子足球运动员的有氧能力。     

儿童青少年体能发展敏感期相关热点问题

近年来,旨在提高儿童青少年体质健康的研究众多,其中儿童青少年体能发展敏感期问题的研究正成为热点研究。通过文献资料法和逻辑分析法等,对近30年来“敏感期”相关文献进行梳理。研究表明：国内外“敏感期”的界定标准不统一,难以形成科学成果;“敏感期”干预方法单一,缺乏综合干预方法;“敏感期”与“非敏感期”干预效果的研究还存在争议。研究认为：“敏感期”不仅受儿童青少年生理、心理因素的影响,同时遗传、环境、社会经济等对“敏感期”也具有重要作用。因此,未来应深入研究“敏感期”的构成因素,重视理论研究与实践研究相结合,强化“敏感期”的综合研究。