Kinematic analysis of the drag flick in field hockey     

Rony Ibrahim  Gert S. Faber  Jaap H. van Dieën 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(1):45-57

Attaining high speed of the stick head and consequently of the ball is essential for successful performance of the drag flick in field hockey, but the coordination pattern used to maximise stick head speed is unknown. The kinematics of the drag flick was studied in ten elite hockey players who performed twenty shots each towards a target located 1.5 m high. A 150 Hz active marker motion analysis system was used, alongside two force plates to detect foot touchdown. Angular velocity and contribution to stick endpoint speed of upper body joints were analysed. Repeated measures ANOVA was used to compare timing of onset and peak angular velocities between joints. Participants used a kinematic pattern that was close to a proximal-to-distal sequence. Trunk axial rotation and lateral rotation towards the target, right wrist flexion and left wrist extension were the main contributors to stick endpoint speed. Coaches should emphasise trunk rotations and wrist flexion and extension movements for maximising stick head speed. Given the high level of the participants in this study, the coordination of joints motions, as reported here, can serve as a guideline for drag flick training.  相似文献   

档案馆信息生态链涵义、结构与类型探析     

康蠡  田彬 《北京档案》2016,(6):10-13

本文在定义档案馆信息生态链的基础上阐述其内涵,认为档案馆信息生态链包含信息人、信息和链接三个基本要素。其主要的结构形态是多链星型结构和多链网状结构。按照不同的分类标准,档案馆信息生态链又可以划分为多种类型。  相似文献   

Hip and upper extremity kinematics in youth baseball pitchers     

Taylor Holt 《Journal of sports sciences》2016,34(9):856-861

The purpose of this study was to examine the relationship between dynamic hip rotational range of motion and upper extremity kinematics during baseball pitching. Thirty-one youth baseball pitchers (10.87 ± 0.92 years; 150.03 ± 5.48 cm; 44.83 ± 8.04 kg) participated. A strong correlation was found between stance hip rotation and scapular upward rotation at maximum shoulder external rotation (r = 0.531, P = 0.002) and at ball release (r = 0.536, P = 0.002). No statistically significant correlations were found between dynamic hip rotational range of motion and passive hip range of motion. Hip range of motion deficits can constrain pelvis rotation and limit energy generation in the lower extremities. Shoulder pathomechanics can then develop as greater responsibility is placed on the shoulder to generate the energy lost from the proximal segments, increasing risk of upper extremity injury. Additionally, it appears that passive seated measurements of hip range of motion may not accurately reflect the dynamic range of motion of the hips through the progression of the pitch cycle.  相似文献   

重金属污染土壤的化学治理和修复     

杨秀丽  王学杰 《浙江教育学院学报》2002,(4)

综合国内外研究现状,简要介绍了各种治理和修复重金属污染土壤的化学方法。  相似文献   

英国超市消费现象分析及其启示     

宋涛 《新乡师范高等专科学校学报》2002,16(1):47-48

英国超市消费逐年增长 ,其经营方式更加灵活 ,销售领域更加广泛。中国是一个人口大国 ,随着居民收入水平的不断提高 ,消费水平也必然不断提高 ,如何使我国超市消费成为新的消费热点 ,引导超市经营向良性发展 ,我们可以透过英国超市消费现象 ,得到很好的启迪  相似文献   

EDGE技术在中国移动GSM网络中的应用前景     

左自刚 《教育技术导刊》2007,(3)

根据EDGE标准的发展、技术特点与优势,对EDGE在中国移动GSM网络中的应用进行了探讨,重点分析了目前的投资风险及价值链成长现状。  相似文献   

蔬菜供应链利益分配问题初探   总被引：2，自引：0，他引：2  

冷建飞 《江苏经贸职业技术学院学报》2006,(2)

蔬菜供应链中各节点企业的风险承担和利益分配不均衡。要合理解决上述问题,就必须规范蔬菜供应链运营环境,加速蔬菜供应链中各企业之间的信息流通,培育蔬菜龙头企业品牌,促进企业做大做强。  相似文献   

中国动漫产业的现状分析     

戎宁  陈彦许 《河北软件职业技术学院学报》2007,9(1):41-42,48

动漫产业是融艺术、科技、出版、玩具制造、商业、旅游、服装等于一体的综合性现代化大型产业.目前,中国社会需求结构和消费结构正在发生深刻的变化.人们开始追求一种精神文化含量更高的生活和消费,社会经济开始向精神--文化消费转型.从世界范围看.动漫早己成为满足人们精神文化生活的产品.动漫产业因此成为发达国家的重要支柱产业.因此有必要采取动态的研究方法,对动漫产业链的构造与互动问题加以研究.  相似文献   

感性设备同名端的判断     

万学斌 《孝感职业技术学院学报》2002,5(1):76-79

本文介绍了一些常见感性设备同名端判断的方法,对其正确使用和维护有重要的实际意义。  相似文献   

“尊重学生”的管理机制   总被引：3，自引：0，他引：3  

程凤春 《教育理论与实践》2003,(23)

为了使尊重学生的原则落到实处,需要教育管理制度的保证。为此,学校可以尝试在管理机制上进行改进,包括施行组织结构扁平化,内部顾客链和倒金字塔组织模式,双向闭合评价模式。为使这些管理机制有效发挥作用,学校应该从整个制度建设出发系统考虑。  相似文献