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Most assessments of segmental sequencing in throwing, striking or kicking have indicated a proximal-to-distal sequencing of end-point linear speeds, joint angular velocities, segment angular velocities and resultant joint moments. However, the role of long-axis rotations has not been adequately quantified and located in the proximal-to-distal sequence. The timing and importance of pronation-supination in the development of racquet head speed have been examined in the tennis serve and squash forehand drive and considered in relation to conventional concepts of proximal-to-distal sequencing. Both long-axis rotations reached their peak angular speeds late in both strokes, typically after shoulder flexion-extension, shoulder abduction-adduction and elbow extension. These results clarify and confirm the importance of upper limb long-axis rotations in the production of racquet head speed. It appears that traditional proximal-to-distal sequencing concepts are inadequate to describe accurately the complexity of the tennis serve or squash forehand drive. It is essential to consider upper arm and forearm longitudinal axis rotations in explaining the mechanics of these movements and in developing coaching emphases, strength training schedules and injury prevention programmes. 相似文献
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Kristensen LB Andersen TB Sørensen H 《Sports biomechanics / International Society of Biomechanics in Sports》2004,3(2):195-208
This study looks at segmental movements in the jumping header from an optimization viewpoint. Investigations on the header so far have focused on head restriction in the movement but have not clarified how and to what extent body segments influence the performance of the skill. In the present study a biomechanical model was used to analyze the jumping header in simulated competition to give a clear picture of an optimized header. Skilled soccer players headed balls at speeds of 13 m x s(-1) the results indicated that the head moves as a free non-restricted segment in the jumping header and should be allowed to do so, even though much soccer literature says otherwise to prevent injuries. The arm movement showed individual characteristics and gave no general advantages in optimizing ball speed after impact in the header The movement of the legs was, on the other hand, the single most important factor in the skill. Therefore, coaches and players shouldfocus on developing muscle strength in the stomach, back and pelvis and should put no restrictions on head and arm movement to optimize the jumping header. 相似文献
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体育消息是体育新闻的基本体式。但报纸体育新闻写作消息头缺失现象却十分严重,从某种程度上说,不仅影响了消息结构的完整性和规范性,甚至还会使人对消息来源的真实性和权威性产生疑问。从体育报纸消息头使用的必要性与缺失的危害、消息头缺失的原因探析及防止消息头缺失的建议等几个方面进行初步的探讨。 相似文献
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叶玮玮 《上海体育学院学报》1989,(3)
我国篮球训练理论在现有基础上应有新的突破,并提出“环节论”观点:(一)“环节论”的定义;(二)“环节论”体现了篮球对抗的整体规律;(三)“环节论”的核心——积极转化;(四)狠抓“两头”,关键在“转化”。 相似文献
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对现代奥林匹克运动中运动员主体缺失的哲学思考 总被引:1,自引:1,他引:1
研究认为现代奥林匹克运动是随着科技的发展而不断发展,在这一过程中,科技帮助人在奥林匹克运动中彰显了自己作为主体的地位,但由于人们越来越依赖于科技,使得科技与人共同承担了运动过程与结果,造成运动员的主体地位的缺失。 相似文献
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我国体育赞助市场诚信缺失的原因及维护对策 总被引:1,自引:0,他引:1
从体育赞助市场诚信缺失的原因入手,全面分析我国体育赞助市场诚信缺失的表现,并对我国体育赞助市场诚信缺失的行为进行剖析,在此基础上针对我国体育赞助市场中的诚信缺失行为提出针对性的措施.研究认为我国体育赞助市场法制建设落后于发展需求,体育赞助市场各关联方对诚信重要性认识不足.目前,需完善法律法规,建设强有力的道德约束机制,才能有效改进我国体育赞助市场的诚信环境,不断促进我国体育赞助市场的健康有序发展. 相似文献
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The role of upper torso and pelvis rotation in driving performance during the golf swing 总被引:1,自引:2,他引:1
While the role of the upper torso and pelvis in driving performance is anecdotally appreciated by golf instructors, their actual biomechanical role is unclear. The aims of this study were to describe upper torso and pelvis rotation and velocity during the golf swing and determine their role in ball velocity. One hundred recreational golfers underwent a biomechanical golf swing analysis using their own driver. Upper torso and pelvic rotation and velocity, and torso-pelvic separation and velocity, were measured for each swing. Ball velocity was assessed with a golf launch monitor. Group differences (groups based on ball velocity) and moderate relationships (r > or = 0.50; P < 0.001) were observed between an increase in ball velocity and the following variables: increased torso-pelvic separation at the top of the swing, maximum torso-pelvic separation, maximum upper torso rotation velocity, upper torso rotational velocity at lead arm parallel and last 40 ms before impact, maximum torso-pelvic separation velocity and torso-pelvic separation velocity at both lead arm parallel and at the last 40 ms before impact. Torso-pelvic separation contributes to greater upper torso rotation velocity and torso-pelvic separation velocity during the downswing, ultimately contributing to greater ball velocity. Golf instructors can consider increasing ball velocity by maximizing separation between the upper torso and pelvis at the top of and initiation of the downswing. 相似文献
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抛跳技术是我国双人滑的优势技术,通过对中外选手抛后外结环3周跳的技术进行对比,找出我国抛跳技术的特殊性,为双人滑选手提供技术参考. 相似文献
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通过对两种扣球动作击球瞬时速度的定量化研究和公式推导,从理论上说明在排球扣球中,抡臂扣球动作的击球速度快于屈臂动作。 相似文献
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Jolly S 《Journal of sports sciences》2010,28(14):1625; author reply 1627-1625; author reply 1630
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郑友训 《徐州教育学院学报》2006,21(2):1-3
研究性学习是以培养学生自主探索精神为特征的一种教学方式,其主阵地在课堂。只有课堂的学习方式发生变革,才能有效地促进学生研究能力的发展。 相似文献
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Exercise in the heat poses a formidable challenge to the body's ability to control its internal environment due to the high rates of metabolic heat production and heat gain by physical transfer from the environment. In an attempt to restrict the rise in core temperature, an increased rate of sweat secretion onto the skin is invoked. This may limit the rise in core temperature, and can prolong the time before a limiting temperature is attained, but it does so at the cost of a loss of body water and electrolytes. The effects of the diminished blood volume are offset to some extent by cardiovascular adaptations, including an increased heart rate and an increased peripheral resistance, but these are insufficient to maintain functional capacity when blood volume is reduced. Prior dehydration will impair performance in both prolonged exercise and short-term high-intensity exercise. Athletes living and training in the heat may experience chronic hypohydration due to inadequate replacement of fluid losses. The negative consequences of exercise in the heat are attenuated to some extent by a period of adaptation, and by the ingestion of water or other appropriate fluids. Optimum fluid replacement strategies will depend on the exercise task, the environmental conditions and the individual physiological characteristics of the athlete. Manipulation of pre-exercise body temperature can also influence exercise performance and may be a strategy that can be used by athletes competing in stressful environments. 相似文献
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Stuart ME 《Research quarterly for exercise and sport》2003,74(4):445-454
Sport offers opportunities for children to identify and resolve moral issues. Moral issues in sport have primarily been studied from the researcher's perspective, with the child's perspective relatively ignored. Thus, the purpose of this study was to explore the nature and content of the issues children experienced in sport. Interview participants consisted of 7 boys and 8 girls ranging in age from 10 to 12 years (M = 11.6 years, SD = 1.7) who had competitive youth sport experience. An inductive content analysis revealed that children identified issues surrounding three overall dimensions concerning fairness of adult's actions, negative game behaviors, and negative team behaviors. Specific examples of issues included unfair actions by coaches, disrespecting opponents, and selfish behavior in practice. The self-identified issues both confirmed and expanded upon the content found in hypothetical moral dilemmas in sport. 相似文献
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Vallerand et al. (2003) developed a dualistic model of passion, wherein two types of passion are proposed: harmonious (HP) and obsessive (OP) passion that predict adaptive and less adaptive interpersonal outcomes, respectively. In the present research, we were interested in understanding the role of passion in the quality of coach-athlete relationships. Results of Study 1, conducted with athletes (N=157), revealed that HP positively predicts a high-quality coach-athlete relationship, whereas OP was largely unrelated to such relationships. Study 2 was conducted with coaches (N=106) and showed that only HP positively predicted the quality of the coach-athlete relationship. Furthermore, these effects were fully mediated by positive emotions. Finally, the quality of the coach-athlete relationship positively predicted coaches' subjective well-being. Future research directions are discussed in light of the dualistic model of passion. 相似文献
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近代中国文化的发展是在西方近代文化的参照系统下,对传统中国文化的一种离异,呈现出向西方近代文化靠近的趋向,这在某种程度上就导致了我们民族文化呈现出不断的流失.以中国武术的传统文化特性为研究对象,通过大量的文献资料的查阅,在文化学理论的指导下,首先对"文化先锋"这一文化学概念进行论述;其次围绕中国武术所具备文化先锋特质展开研究,分析中国武术文化的独创性、区域特性以及动态性的文化特征;最后指出中国武术文化作为中国传统文化的典型代表,其中蕴藏着深厚的传统文化的精髓和气质,因此,中国武术对于传统文化的回归,有着文化先锋的作用. 相似文献
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视力健康:大学健康教育的薄弱环节 总被引:2,自引:0,他引:2
分析了现代大学生视力健康的状况及影响因素,并有针对性的提出了增强大学生视力健康的对策,为有关部门制定政策、学校制定健康教育计划以及学生进行自我视力保健提供参考。 相似文献