乒乓球运动员膝关节损伤机制研究——对3种常用步法的膝关节负荷特征分析     

周星栋  肖丹丹  郭文霞  黄习梅  张晓栋 《中国体育科技》2020,(6):62-67

目的:了解不同性别乒乓球运动员完成并步、跳步、跨步3种常用步法时膝关节的负荷特征,并探析乒乓球运动员膝关节的损伤机制。方法:对乒乓球男、女各10名运动员完成3种常用步法动作时的下肢运动学、动力学数据进行采集和处理,并运用方差分析法比较不同性别、不同技术之间的差异。结果:受试者在完成3种步法过程中,膝关节屈角大致范围在20°~60°。当地面反作用力最大时,女运动员比男运动员表现出更小的外展角(P<0.05),跳步比并步和跨步表现出更小的外展角(P<0.05);在三维受力方面,膝关节受到垂直方向上的力最大,水平向后和向左的力次之,未表现出显著的性别差异和技术差异;在三维力矩方面,膝关节受到的伸膝力矩较大,也未表现出显著的性别差异和技术差异。结论:膝关节屈曲状态下,较大的地面反作用力和膝关节外展角易导致乒乓球运动员前交叉韧带损伤,女运动员的损伤风险小于男运动员,跳步的损伤风险小于并步和跨步;水平向后和向左的力易造成乒乓球运动员软骨和半月板损伤;过大的伸膝力矩易导致乒乓球运动员髌腱末端病和髌骨软化。  相似文献   

Longitudinal relationships between syntactic skills and Chinese written composition in Grades 3 to 6     

Pui-sze Yeung  Connie Suk-han Ho  David Wai-ock Chan  Kevin Kien-hoa Chung 《Journal of Research in Reading》2020,43(2):201-228

  相似文献   

The effect of number of siblings and birth order on educational attainment: Empirical Evidence from Chinese General Social Survey     

《International Journal of Educational Development》2020

Data from China demonstrate that the effect of the number of siblings on education is restricted by many factors, such as children’s gender, urban or rural household registration, whether there is only one child, the birth order of children within the family, and parents’ status. Chinese families have significant preferences for the eldest son and the youngest son. Moreover, research based on the natural experiment and instrumental variable approach suggests that market-oriented reform of education has increased the cost of family education expenditures since China’s reform and opening up, which further aggravates the negative impact on education of having many siblings in an urban setting.  相似文献   

小学生《“阅读·探究·体验”手册》开发研究--以《绿山墙的安妮》手册开发为例     

屈春玉 《教育教学论坛》2020,(17):96-97

该文认为,《"阅读·探究·体验"手册》是学生阅读的助手,设计时考虑到整体构建章节与整本书阅读相结合。同时,明确主线,整本书阅读的探究要围绕主线展开,在构建手册时,明确整本书阅读探究的核心要点。在开发《"阅读·探究·体验"手册》时,充分考虑到语文学科的核心素养,通过编制手册,提升学生的语文核心素养。  相似文献   

中国武术功夫论的身体素养意蕴与价值     

张震 《武汉体育学院学报》2020,54(10):58-64

运用文献资料法和中国哲学诠释学方法，在"技道并进""德艺双馨"的优秀文化传统和"功夫所至即是本体"的哲学范式下，提出：武术功夫是一个三维合一的概念，其既涵摄本体与主体，亦包纳才艺与能力，还囊括了方法与规则。从"功力"角度看，功夫具备本体的性质，指的是类似禅、太极等理念在长时间实践中的现身性表达；从"功用"的角度看，功夫就是一种高级的搏击竞技能力或表演才艺；从"功法"的角度看，功夫表征了方法运用的得当。其蕴藏了：（1）神形共建；（2）在人伦日用中寻求终身技能的发展；（3）身体技艺与情感意志共同成长三层"元实践"哲学意蕴。功夫旨在塑造整体的人、具体的人和自我超越的人，这无疑与身体素养所强调的"身体锻炼与人格培养并举"的整体论哲学在逻辑上相贯通。武术功夫在语义和哲学内涵两个层面上与身体素养有着极强的互释性，属于中国本有的身体素养思想，这就使得功夫修炼具备了提升当代人身体素养和助推当今武术发挥更广义的教育价值之重要意义。  相似文献   

习惯行为、执行意向与青少年身体活动意向与行为:基于计划行为理论的扩展模型     

王丽娟  郑丹蘅 《上海体育学院学报》2020,(2):22-32

在计划行为理论(TPB)的基础上,引入身体活动习惯行为与执行意向,构建扩展TPB(METPB)模型,检验该模型对9~19岁青少年群体的中高强度身体活动(MVPA)的适用性,探讨该模型对小学、初中及高中阶段青少年MVPA影响的差异。结果显示:假设模型的拟合度可以接受,纳入习惯行为与执行意向后,METPB显著地提高了其对身体活动行为的解释力。态度和感知行为控制对MVPA行为意向有显著性影响,解释了31.4%的行为意向方差;行为意向和习惯行为对MVPA行为有显著性影响,解释了18.7%的行为方差;执行意向加强了行为意向朝实际行为的转换。METPB模型对于不同学习阶段青少年MVPA意向及行为的影响有显著性差异。其中:主观规范对小学生与初中生MVPA意向产生了显著性影响,而对高中生的MVPA意向并无显著性影响;感知行为控制对3个阶段学生的MVPA意向产生的影响随着学习阶段的上升不断增强。建议:在对于青少年身体活动的干预中,政府、家庭、学校应重视培养学生对于身体活动参与的正确态度,提高其参与身体活动的意愿,培养其参与身体活动的行为习惯,且在对青少年身体活动干预时考虑学习阶段的差异。  相似文献   

Child maltreatment and adult depressive symptoms: Roles of self-compassion and gratitude     

《Child abuse & neglect》2018

Child maltreatment, including abuse (physical, emotional, and sexual) and neglect (physical and emotional), is positively associated with depressive symptoms in adulthood. However, most studies have been conducted within a psychopathological framework and focused on underlying dysfunctional processes (e.g., insecure attachment styles, maladaptive schemas, and negative attribution styles). Protective factors that affect the relationship between child maltreatment and adult depressive symptoms are underexplored. Guided by emotion regulation theory and the perspective of positive psychology, we examined the roles of self-compassion and gratitude as protective factors in the relationship between child maltreatment and adult depressive symptoms in a sample of 358 college students. Results showed that psychological maltreatment (emotional abuse and emotional neglect) was associated with adult depressive symptoms through decreased self-compassion. Neglect (emotional neglect and physical neglect) and sexual abuse were associated with adult depressive symptoms through decreased gratitude. There was no association between physical abuse and depressive symptoms through either self-compassion or gratitude. Our findings suggest that clinical practices focusing on self-compassion and gratitude might help prevent the development of adult depressive symptoms among clients with a history of maltreatment in childhood.  相似文献   

Exploring the complex and non-linear evolution of Chinese international students’ experiences in US colleges     

Tang T. Heng 《高等教育研究与发展》2018,37(6):1141-1155

This article contests the narrative of Chinese international students (internationals for short) as passive and problematic to reveal the complexity and fluidity of their experiences. Simultaneously, it troubles the overly linear approach of stage theory in understanding internationals’ adjustment. Following nine first- and nine second-year students in US colleges over a year and involving them in semi-structured interviews and journal prompts, this research examined how they evolved. Findings show that while participants grew on academic and personal fronts, their experiences remained multi-dimensional, with second years being less sanguine and reporting challenges different from first years. This article argues that seeing Chinese internationals’ evolution as an uneven ascent affords a more nuanced understanding compared to a U-shape stage theory as it recognizes that while internationals are evolving, new situations provide challenges which they learn to overcome. Consequently, Chinese internationals’ growth troubles the deficit discourse around them and departs from pre-existing research around postgraduates. Findings spell implications for how the college community should enhance transcultural understanding and how future research around internationals could develop.  相似文献   

Motivation counteracts fatigue-induced performance decrements in soccer passing performance     

Jeroen C.M. Barte  Arne Nieuwenhuys  Sabine A.E. Geurts  Michiel A.J. Kompier 《Journal of sports sciences》2019,37(10):1189-1196

Recent theories suggest that negative effects of fatigue on performance are determined by perception of effort and motivation rather than being directly caused by reaching physiological limits. In the current experiment, the influence of motivation on fatigue-induced decrements in soccer performance was experimentally investigated. Sixty amateur soccer players performed a validated soccer-passing test before and after a fatigue protocol. Results showed that players’ motivation and performance decreased after the fatigue protocol for players in the control group. In contrast, players in the motivation group (i.e., with motivation experimentally induced after the fatigue protocol) were able to uphold their motivation and increase their performance. These results indicate that motivation plays a crucial role in performance under fatigue, as fatigue-induced decrements in soccer passing performance can be counteracted by high levels of motivation. Future research may explore the limits of this counteracting effect and extend findings to other relevant performance aspects.  相似文献   

Differences between motion capture and video analysis systems in calculating knee angles in elite-standard race walking     

Brian Hanley  Catherine B. Tucker  Athanassios Bissas 《Journal of sports sciences》2018,36(11):1250-1255

Race walking is an event where the knee must be straightened from first contact with the ground until midstance. The aim of this study was to compare knee angle measurements between 2D videography and 3D optoelectronic systems. Passive retroreflective markers were placed on the right leg of 12 race walkers and 3D marker coordinate data captured (250 Hz), with 2D video data (100 Hz) recorded simultaneously. Knee angle data were first derived based on the markers’ coordinates, and separately by using a 3D model that also incorporated thigh and shank clusters; the video data were analysed using both automatic tracking and manual digitising, creating four conditions overall. Differences were calculated between conditions for stance (using root mean square values), and at discrete events. There were few differences between systems, although the 3D model produced larger angles at midstance than using automatic tracking and marker coordinates (by 3 – 6°, P < 0.05). These differences might have occurred because of how the 3D model locates the hip joint, and because of the addition of marker clusters. 2D videography gave similar results to the 3D model when using manual digitising, as it allowed for errors caused by skin movement to be corrected.  相似文献