The biomechanical characteristics of high-performance endurance running     

Stephen J. Preece  Christopher Bramah  Duncan Mason 《European Journal of Sport Science》2019,19(6):784-792

The biomechanical profile of high-level endurance runners may represent a useful model that could be used for developing training programmes designed to improve running style. This study, therefore, sought to compare the biomechanical characteristics of high-performance and recreational runners. Kinematic and kinetic measurements were taken during overground running from a cohort of 14 high-performance (8 male) and 14 recreational (8 male) runners, at four speeds ranging from 3.3 to 5.6?m?s^?1. Two-way ANOVA analysis was then used to explore group and speed effects and principal component analysis used to explore the interdependence of the tested variables. The data showed the high-performance runners to have a gait style characterised by an increased vertical velocity of the centre of mass and a flight time that was 11% longer than the recreational group. The high-performance group were also observed to adopt a forefoot strike pattern, to contact the ground with their foot closer to their body and to have a larger ankle moment. Importantly, although observed group differences were mostly independent of speed, the tested variables showed a high degree of interdependence suggesting an underlying unitary phenomenon. This is the first study to compare high-performance and recreational runners across a full range of kinematic and kinetic variables. The results suggest that high-performance runners maintain stride length with a prolonged aerial phase, rather than by landing with a more extended knee. These findings motivate future intervention studies that should investigate whether recreational runners could benefit from instruction to decrease shank inclination at foot contact.  相似文献   

Where are all the males? Gender-specific typologies of childhood adversity based on a large community sample     

《Child abuse & neglect》2019

BackgroundMethodological issues have been identified when quantifying exposure to adversity and abuse. To address a single type may obscure covarying effects. To sum multiple exposures gives equal weight to each. Latent class analysis (LCA) addresses this by identifying homogenous subpopulations. Most studies using LCA have pooled gender data in spite of evidence that the nature and frequency of exposure differs by gender. Males report more interpersonal abuse, females report more of other exposures, particularly sexual.ObjectiveThis study aimed to identify if stratifying data by gender resulted in different profiles of adversity/abuseParticipants and setting: The National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) wave II, a large community-based survey, nationally representative of the US population.MethodThis study used 14 indicators of childhood adversity as the basis for LCA.ResultsThe number and nature of classes differed by gender. The best solution for females was 4-class: a low risk class; a class at higher risk of sexual abuse; a class at higher risk of physical abuse; a class at higher risk of combined physical and sexual abuse. The best solution for males had only 3-classes; a low risk class, a class at higher risk of sexual abuse; a class at higher risk of physical abuse. The combined dataset resulted in a solution similar to the female solution.ConclusionThe importance of developing models for males and females separately was evidenced by the male and female classes being differentially associated with mental health variables.  相似文献   

Ethical and political dimensions of action research and lesson study: reflections from a research project on a controversial issue in Cyprus     

Polyxeni Stylianou  Michalinos Zembylas 《Educational Action Research》2019,27(4):581-594

ABSTRACT

As educational interventions that integrate death issues in the school curriculum are rarely designed, implemented and evaluated, our action research (AR) project aimed at investigating the complexities of integrating the concepts of loss and grief in the primary school curriculum of Cyprus. The purpose of this paper is to identify and analyze convergences and divergences between AR and lesson study (LS), as they emerged in our project. We particularly focus on the ways that AR served to legitimate ethically and politically those aspects of the project that constituted the experimentation of lesson plans on loss and grief. The AR and LS elements of our project functioned differently and served different purposes, and we speculate that this is not irrelevant to the controversial aspects of the lesson plans’ topic, namely loss and grief. The paper argues that it may be strategically important, for ethical and political reasons, to both demarcate and associate AR and LS, navigating between them, particularly if a controversial issue is involved.  相似文献   

我国校园足球可持续发展的若干问题研究          下载免费PDF全文

黄山 《河北体育学院学报》2019,33(2):66-69

发展校园足球是推进我国校园体育活动的重要力量，亦是提升我国足球运动水平的必然选择。虽然在相关政策的支持下，我国校园足球发展迅速，但依然面临经费短缺、师资不足、发展不均衡、学训矛盾突出、体制机制不完善、社会认可度不高、医疗保障体系不健全等问题。指出，学校应密切联系俱乐部、企业，多渠道获取发展资源；从内部培养与外部引进两方面充实师资力量；坚持全面发展原则，妥善解决学训矛盾，提升学生综合素质；加强足球文化建设，营造良好氛围，提升足球参与者的荣誉感；强化校园足球风险防范意识，加强风险管理。旨在促进我国校园足球健康可持续发展。  相似文献   

Investigating Identity: Gender,Overseas Experience,and Japanese Youth     

Erina Ogawa 《Journal of Intercultural Communication Research》2019,48(3):185-202

Identity is prominent in academia, despite it being difficult to define and measure due to its dynamic and multifaceted nature. In Japan, awareness of the make-up of Japanese youth is increasingly crucial as Japan becomes a more internationalized and ageing society. This paper examines, by identity mapping and discriminant analysis, the cultural identities of 94 Japanese youth. While strong Global identities separated the respondents with from without overseas experience, ties to National identities and Relationships were found respectively for males and females. This paper suggests that regarding the study of cultural identities, gender does matter – at least in Japan.  相似文献   

基于“立德树人”的我国青少年体育品德评价指标体系构建研究     

汤利军  蔡皓 《武汉体育学院学报》2019,53(10):75-80

运用文献资料法、问卷调查法、德尔菲法、层次分析法等研究方法，以人的全面发展理论、马斯洛的需要层次理论、道德认知发展心理学理论为基础，以国家出台的各类关于学生道德、品德发展的文件、中小学生手册和奥林匹克精神等为依据，构建出青少年体育品德评价指标体系。指标体系包括体育精神、体育品格、体育道德行为3个一级指标，爱国主义精神、集体主义精神、竞争开拓精神、拼搏进取精神、团队合作精神、创新精神、法制精神、爱、志、信、义、体育道德意应能力、体育道德创造能力和体育道德自我教育能力14个二级指标，并采用层次分析法分析出各指标的权重。青少年体育品德评价指标体系具有一定的科学性、适用性及操作性。  相似文献   

基于因子分析和曲线拟合的集装箱吞吐量预测     

贾飞跃  韩晓龙 《上海海事大学学报》2019,40(2):18-22

为提高集装箱吞吐量的预测精度,提出基于因子分析和曲线拟合的集装箱吞吐量预测模型。以上海港为例,通过因子分析,分析影响集装箱吞吐量的主要因素,筛选出主因子,得到不同年份的综合经济发展值;再运用曲线拟合方法,建立以综合经济发展值为自变量,以集装箱吞吐量为因变量的三次曲线模型;运用自回归积分移动平均(autoregressive integrated moving average,ARIMA)模型预测2016—2020年的综合经济发展值,进而求得2016—2020年上海港集装箱吞吐量预测值。结果表明:该模型的拟合效果和预测精度均较高,可以运用到集装箱吞吐量预测中。给出上海港在国内经济新常态下转型升级的建议。  相似文献   

Understanding the track and field sprint start through a functional analysis of the external force features which contribute to higher levels of block phase performance     

Neil Edward Bezodis  Sean Peter Walton  Ryu Nagahara 《Journal of sports sciences》2019,37(5):560-567

This study aimed to identify the continuous ground reaction force (GRF) features which contribute to higher levels of block phase performance. Twenty-three sprint-trained athletes completed starts from their preferred settings during which GRFs were recorded separately under each block. Continuous features of the magnitude and direction of the resultant GRF signals which explained 90% of the variation between the sprinters were identified. Each sprinter’s coefficient score for these continuous features was then input to a linear regression model to predict block phase performance (normalised external power). Four significant (p < 0.05) predictor features associated with GRF magnitude were identified; there were none associated with GRF direction. A feature associated with greater rear block GRF magnitudes from the onset of the push was the most important predictor (β = 1.185), followed by greater front block GRF magnitudes for the final three-quarters of the push (β = 0.791). Features which included a later rear block exit (β = 0.254) and greater front leg GRF magnitudes during the mid-push phase (β = 0.224) were also significant predictors. Sprint practitioners are encouraged, where possible, to consider the continuous magnitude of the GRFs produced throughout the block phase in addition to selected discrete values.  相似文献   

新时代中国武术传承发展的困境与消解     

李臣  郭桂村  张帆 《武汉体育学院学报》2019,53(7):65-70

采用文献资料、文本分析等研究方法，运用文化学、传播学和社会学等多学科理论知识，以建设社会主义文化强国国家意志为引领，对新时代中国武术传承发展的时代境遇、面临困境和应对策略进行了学理上分析与设计。认为，建设文化强国的国家意志，助推民族历史发展彰显的独特文化效益和深度国际传播多元势力透显的使命担当，为中国武术当代发展创造了新机遇和新空间。而新时期文化的现代话语体系挤压着中国武术传统的话语空间，文化全球化横向传播方式削减着中国武术纵向代际传承效益，文化发展的同质化趋势消解着中国武术异质化传承栖息地等现实困境，迫切需要有序开启从传统向现代转型尤应注重中国武术价值观传承，以内承外传实现代际传承与同辈横向交流效益，构建中国武术文化多样性推进其传承发展时代认同三位一体推进路径，进行精准施策与理性应对。  相似文献   

船舶靠泊过程中系缆作业仿真     

代广树 《上海海事大学学报》2019,40(4):17-21

为更加准确直观地模拟船舶靠泊过程中的系缆作业,将缆绳分为两部分进行建模。对缆机滚筒上的缆绳提出缠绕算法模型,计算出缆绳随着滚筒旋转的收放速度,实现使用滚筒收放缆绳的模拟。对缆机滚筒外的缆绳建立悬链线模型,计算出缆绳在不同工况下的形状和端点处的受力情况,并根据计算出的缆绳张力是否超出安全负荷对缆绳进行破断分析。根据船舶和码头形状确定碰撞检测区域,采用基于距离场的碰撞检测方法实现缆绳与船体、缆绳与码头之间的碰撞检测。通过模拟缆绳在系缆作业过程中的形状、位置和姿态变化,实现船舶靠泊过程中系缆作业的三维可视化。  相似文献