Reviewing the Variability-Overuse Injury Hypothesis: Does Movement Variability Relate to Landing Injuries?     

Andrew D. Nordin  Janet S. Dufek 《Research quarterly for exercise and sport》2019,90(2):190-205

Purpose: Overuse injuries are common in sport, but complete understanding of injury risk factors remains incomplete. Although biomechanical studies frequently examine musculoskeletal injury mechanisms, human movement variability studies aim to better understand neuromotor functioning, with proposed connections between overuse injury mechanisms and changes in motor variability. Method: In a narrative review, we discuss the variability-overuse injury hypothesis, which suggests repeated load application leads to mechanical tissue breakdown and subsequent injury when exceeding the rate of physiological adaptation. Due to the multidisciplinary nature of this hypothesis, we incorporate concepts from motor control, neurophysiology, biomechanics, as well as research design and data analysis. We therefore summarize multiple perspectives while proposing theoretical relationships between movement variability and lower extremity overuse injuries. Results: Experimental data are presented and summarized from published experiments examining interactions between experimental task demands and movement variability in the context of drop landing movements, along with comparisons to previous movement variability studies. Conclusion: We provide a conceptual framework for sports medicine researchers interested in predicting and preventing sports injuries. Under performance conditions with greater task demands, we predict reduced trial-to-trial movement variability that could increase the likelihood of overuse injuries.  相似文献   

我国优秀男子跳远运动员助跑最后两步速度变化特征的研究   总被引：2，自引：0，他引：2  

马俊明 《成都体育学院学报》2003,29(3):50-53

采用现场定点高速摄影、影片分析以及数理统计等方法,通过对助跑最后第三步和最后第二步速度的变化比较、助跑最后第二步摆动腿支撑阶段的速度变化及其动作结构的分析,得出以下结论:我国优秀男子跳远运动员助跑最后第三步至最后第二步摆动腿着地瞬间呈加速状态,助跑最后第二步摆动腿支撑阶段身体重心水平速度下降较小;助跑最后两步身体重心水平速度呈现出增大的趋势。  相似文献   

田径教科书中关于短跑途中跑存在问题商榷   总被引：1，自引：0，他引：1  

王吉夫 《体育学刊》2001,8(2):94-95

在短跑途中跑中，脚着地后髋关节并未弯曲，而是继续伸展：踝、膝关节是被动弯曲，而不是主动弯曲。此刻主动支撑会缩短制动时间，有利于制动冲量的减小。着地缓冲动作的细致划分，对全面正确地认识跑的原理是必要的，着地缓冲阶段应包括前蹬和后蹬的前一部分(垂直部位至最大缓冲)。摆动腿下压动作的作用有重要意义，应引起足够重视，在跑的划分中应有明确的界定。  相似文献   

试论农村初中辍学及其对策     

邱俊武 《黄冈职业技术学院学报》2002,4(1):38-40

目前农村初中辍学客观存在,困扰着农村的“双基”教育。本文分析了农村初中学生辍学的原因,提出了防止学生辍学的具体措施和新的办法。  相似文献   

论新课程改革的"软着陆"   总被引：4，自引：0，他引：4  

查有梁 《教育学报》2007,3(2):16-23

新课程改革需要"软着陆",是指课改的进程要减慢速度,课改的实施要稳步成功.钟启泉教授的一篇对新课程改革的总结性《对话》提出的一系列观点,都不利于课程改革的"软着陆",是对课程改革的误导.这些误导表现出了西方后现代理论在中国课程改革中的一种思潮.新课程改革如何"软着陆",这需要以"科学发展观"为指导.  相似文献   

河南省中长跑运动水平下滑的原因分析及对策研究     

岳新坡  耿雷 《河北体育学院学报》2007,21(2):65-67

运用文献资料法、问卷调查法、测试法和数理统计法,对河南省及我国部分省市的中长跑有关情况进行研究,分析河南省中长跑运动水平下滑的原因并提出相应的对策,为河南省中长跑运动水平的提高提供理论参考。  相似文献   

Increasing plantarflexion angle during landing reduces vertical ground reaction forces,loading rates and the hip’s contribution to support moment within participants     

K. Michael Rowley  James G. Richards 《Journal of sports sciences》2015,33(18):1922-1931

The ankle joint’s role in shock absorption during landing has been researched in many studies, which have found that landing with higher amounts of plantarflexion (PF) results in lower peak vertical ground reaction forces and loading rates. However, there has not yet been a study that compares drop landings within participants along a quantitative continuum of PF angles. Using a custom-written real-time feedback program, participants adjusted their ankles to an instructed PF angle and dropped onto two force platforms. For increasing PF, peak ground reaction force and peak loading rate during weight acceptance decreased significantly. The hip’s contribution to peak support moment decreased as PF at initial contact increased up to 30°. The ankle and knee contributions increased over this same continuum of PF angles. There appears to be no optimal PF angle based on peak ground reaction force and loading rate measurements, but there may be an optimum where joint contributions to peak support moment converge and the hip moment’s contribution is minimised.  相似文献   

应用非线性规划求解月球探测器着陆轨道最优控制     

肖刚 《韩山师范学院学报》2015,(3)

为了减少有限推力作用下月球探测器软着陆所需的燃料消耗,提出了应用非线性规划方法来求解该最优控制问题。首先,将有限推力作用下月球软着陆问题转化为数学上的两点边值问题;在考虑边界条件的前提下,利用拉格朗日原理将该两点边值问题转化为针对控制变量的优化问题;然后应用非线性规划方法求解所形成的参数优化问题。实验仿真结果显示,该方法能够成功实现月面软着陆,表明提出的设计方法简单有效。  相似文献   

基于复杂网络和粒子群算法的滤波与轨道优化模型     

杨凌  许铭 《丽水学院学报》2015,(2):14-21

嫦娥三号已成功完成软着陆,其着陆准备轨道的位置和着陆轨道及其控制策略是嫦娥三号月球着陆的关键问题。运用天体物理相关理论及智能优化算法构建了基于复杂网络的滤波模型和基于粒子群算法的着陆轨道优化模型,并通过matlab计算及matlab仿真,给出了着陆轨道及其控制策略。  相似文献   

飞机起落架系统简介     

陈永新 《大众科技》2014,(6):127-128,130

简单介绍飞机起落架的作用、配置形式、结构形式、组成、发展历史,使非起落架专业人士对起落架有所了解。  相似文献