我国优秀男子标枪运动员“交叉步”和最后用力投掷技术的生物力学探析

通过对高速摄影影片的解析获得大量有价值的参数。发现我国优秀男子标枪选手的“交叉步”中,左肩、左臂出现上翘和上体过早后仰或后倒是使“交叉步”的步幅过大、重心腾起过高的主要原因并由此而影响最后用力效果。     

我国优秀男子标枪运动员从交叉步到出手技术生物力学分析

采用高速摄影等方法,从生物力学角度对我国优秀男子标枪运动员交叉步、最后用力的技术和出手参数进行了分析,发现我国男子标枪运动员在进入交叉步时上体过早后仰或后倒、两腿“剪绞”动作存在不合理现象以及最后用力时自下而上各环节的发力和力的传递存在明显缺陷等,这是影响其运动成绩提高的主要因素。     

标枪交叉步技术教学规格的讨论

标枪的交叉步技术,是将助跑获得的最大速度传递至最后用力的一个重要环节。从投掷步(引枪开始)至最后用力,交叉步起着承前启后的作用,没有了它就不是标枪的完整技术。因此,交叉步又有着它的独立性。然而,正是由于交叉步技术的不正确、不纯熟,以及与前后动作的协调性不够,造成动作减速,技术错误,甚     

标枪最后用力时左腿动作分析

投掷标枪中,左腿在交叉步与最后用力的衔接中起到了引导、制动和支撑的作用。本文从交叉步和最后用力这两个紧密相连的环节中,对左腿的动作及其意义进行了探讨,旨在使我们充分认识左腿在投掷标枪中的作用。     

标枪最后用力时左腿动作生物力学分析

在标枪投掷技术中,左腿在交叉步及最后用力的衔接中起到引导、制动和支撑的作用.从交叉步和最后用力这两个紧密相连的环节中,对左腿的动作及其意义进行生物力学探讨,从而对左腿在投掷标枪中的作用有充分的认识.     

掷标枪“软步”技术的训练

通常把标枪完整技术按任务和动作形式分为握法、持枪助跑、最后用力、缓冲和标枪飞行五个部分。在这里主要对持枪助跑中的交叉步和“软步”进行分析、研究,以其为标枪运动员的“软步”训练提供指导。投掷步的倒     

投掷标枪中的“软步”

一、“软步”的概念及意义运动员做完交叉步,即右脚一落地,此时引枪臂留在后面并迅速地向前做左腿支撑动作,右腿以髋领先用力向前,膝曲前移,我们将这个落地后右髋迅速向前移动,右膝曲伸向前的动作称为投掷标枪中的“软步”或称跪膝姿势。这一动作的良好完成,在最后...     

标枪交叉步落地方法的力学分析

交叉步落地技术是从助跑转入最后用力的关键。交叉步落地方法的正确与否直接影响到最后用力的效果。为了最大限度地把助跑的动量转移到最后用力中去,运动员应采用“滚动式”落地技术。这种技术要求运动员以脚跟先落地,然后过渡到前脚掌。在落地过程中,踝关节始终保持伸位,充分利用惯性将身体重     

掷标枪最后用力过程中左腿技术的运动学分析

用高速摄影机现场拍摄,并通过用影片运动分析系统进行解析对掷标枪最后用力过程中左腿技术进行了运动学分析。研究结果认为,“交叉步”后加快左腿的前摆速度可以形成牢固的双支撑,对重心水平速度的保持与提高有重要作用,并能缩短最后用力的时间。左侧支撑技术是保证最后用力时动量传递和“鞭打”技术有效完成的重要技术环节,并影响着出手高度。     

对我国男子标枪运动员“交叉步”和最后用力技术的某些运动学特征的初探

本文运用影片分析的方法,通过对中外男子优秀标枪运动员掷标枪技术的分析,发现我国运动员“交叉步”腾空过高、过大现象与运动中左肩、左臂上翘有着密切关系,同时发现我国运动员最后用力顺序和最后用力程度存在明显不足。     

Carbohydrate ingestion improves endurance performance during a 1h simulated cycling time trial

This study examined the effect of carbohydrate ingestion on metabolic and performance-related responses during and after a simulated 1h cycling time trial. Eight trained male cyclists (VO 2 peak = 66.5ml kg -1 min -1 ) rode their own bicycles mounted on a windload simulator to imitate real riding conditions. At a self-selected maximal pace, the cyclists performed two 1h rides (separated by 7 days) and were fed either an 8% carbohydrate or placebo solution. The beverages were administered 25 min before (4.5ml kg -1 ) and at the end (4.5ml kg -1 ) of the ride. With carbohydrate feeding, plasma glucose tended (P = 0.21) to rise before the time trial. Compared with rest, the plasma glucose concentration decreased significantly (P < 0.05) at the end of both rides, with no statistically significant difference being observed between treatments. Thereafter, plasma glucose increased significantly (P < 0.05) at 15 and 30 min into recovery, and was significantly higher at 30 min during the carbohydrate trial compared with the placebo trial. No significant changes in plasma free fatty acids were observed during the ride. However, a significant increase (P < 0.05) in free fatty acids was found at 15 and 30 min into recovery, with no difference between trials. Mean power output was significantly (P < 0.05) greater during the carbohydrate compared with the placebo trial (mean - S.E.: 277-3 and 269-3W, respectively). The greater distance covered in the carbohydrate compared with the placebo trial (41.5-1.06 and 41.0–1.06km, respectively; P < 0.05) was equivalent to a 44s improvement. We conclude that pre-exercise carbohydrate ingestion significantly increases endurance performance in trained cyclists during a 1h simulated time trial. Although the mechanism for this enhancement in performance with carbohydrate ingestion cannot be surmised from the present results, it could be related to a higher rate of carbohydrate oxidation, or to favourable effects of carbohydrate ingestion on the central component of fatigue.     

Science and medicine of rowing: A review

The biology and medicine of rowing are briefly reviewed. Effort in a 2000 -m race is about 70% aerobic. Because the boat (and in some instances a cox) must be propelled, successful competitors are very tall, with a large lean mass and aerobic power. Large hearts may lead to erroneous diagnoses of a cardiomyopathy. Large respiratory minute volumes must be developed by chest muscles that are also involved in rowing. The vital capacity is typically large, and breathing becomes entrained. Expiration cannot be slowed relative to inspiration (as normally occurs at high rates of ventilation) and the limiting flow velocity may be reached, with the potential for airway collapse. Performance is strongly related to the power output at the ‘anaerobic threshold’, and lactate measures provide a guide to an appropriate intensity of endurance training. Peak blood lactate levels are higher in males (commonly 11–19 mmol·l -1 and occasionally as high as 25 mmol·l -1) than in females (9–11 mmol·l -1), probably because males have a greater muscle mass in relation to blood volume. The skeletal muscles are predominantly slow twitch in type, developing an unusual force and power at low contraction velocities. Many rowers have a suboptimal diet, eating excessive amounts of fat. Lightweight rowers also have problems of weight cycling. Aerobic power and muscle endurance often change by 10% over the season, but such fluctuations can be largely avoided by a well-designed winter training programme. Injuries include back and knee problems, tenosynovitis of the wrist and, since the introduction of large blades, fractures of the costae.     

我国体育市场管理法规研究

采用调查法和比较法对全国体育市场立法和管理现状进行调查,对部分较早出台并有一定代表性的省市的体育市场管理法规的立法和管理情况进行了研究,提出了体育市场管理立法和管理的原则、基本程序、措施及其一般模式,为规范全国体育市场管理提供参考依据。     

重新认识体育的社会关联

体育与政治之间存在一个悖论，体育的发展与经济实力之间没有直线相关，体育与教育部分重叠，体育与宗教最为近缘，体育可借用科学手段，体育的艺术禀性日益明显，体育与养生反映着两种人生观。     

上海社区体育竞赛参与者的特点探析

本文在专家访谈、问卷调查、数理统计和文献资料分析的基础上,探析了上海社区体育竞赛参与者的特点、参与者对社区体育赛事运作管理的看法等问题。在此基础上从引进社区体育赛事的志愿者、整合社区体育赛事的各种资源、开发社区体育竞赛的无形资产、组建非营利性的专业团队、规范社区体育赛事的服务管理等方面提出了进一步满足上海社区居民日益增长的体育竞赛参赛需求的对策与措施。     

对全面把握游泳训练环节的探讨

从系统观点出发,结合训练实践,对全面把握游泳训练环节进行探讨。认为应强化非智力因素在运动员多年训练中的作用,在育材全过程中不断选材,从整体上把握动态训练的全过程,把培养高水平运动员的整个过程置于一个严格的科学控制之下。     

我国优秀游泳运动员出发技术辅助训练的研究

为改进我国优秀游泳运动员的出发技术,采用观测和实验方法,通过拍摄运动员陆上和水下出发技术录像以及出发计时,对出发技术进行运动生物力学诊断和分析。在此基础上,根据运动员自身特点和不同泳姿提出相应的入水启动方式,并研制出发训练辅助器材,对出发预备姿势、腾起角度以及飞行远度和入水角进行控制。实践证明:这是一种快捷、有效的出发技术辅助训练方法。     

运动性呼吸肌疲劳与耐力性项目的运动能力

影响和限制耐力性运动项目的成绩的生理因素是复杂的和多方面的,取决于训练的强度和运动成绩.大强度持续性运动可导致呼吸肌疲劳.运动性呼吸疲劳可能在决定运动耐量方面起到关键的作用：一方面通过直接影响运动肌力量的生成（外周疲劳）,另一方面,通过肢体用力自感不安反馈引起工作肌运动单位输出功率下降（中枢疲劳）.对呼吸肌进行训练,可能有助于提高耐力性项目的运动成绩.     

Identifying home advantage in international tennis and golf tournaments

A regression analysis of competitors' tournament results in relation to their world rankings was proposed to identify the effect of home advantage in international ‘grand-slam’ tennis and ‘major’ golf tournaments. The results provided little evidence of home advantage in either the grand-slam tennis or the golf tournaments held in 1993. The only possible evidence of home advantage was found in the Wimbledon tennis and the US Open golf championships. Even these findings can be explained, at least partially, by (1) the availability of information concerning the low world rankings of the British tennis players competing at Wimbledon, and (2) selective entry, allowing only the world's top-ranked foreign golfers into the US open golf tournament. In both cases, the lower ranking home competitors have a greater opportunity to perform above their anticipated world rankings. Therefore, provided entry into tennis and golf tournaments is truly ‘open’ to both the host nation's representatives and foreign competitors alike, home advantage does not appear to be a major factor influencing the competitors' performance in such competitions. These findings may be explained by the relatively objective nature of the scoring systems used in tennis and golf, unlike the subjective influence of refereeing decisions on the results of team-games such as soccer.     

对欧洲足球技战术发展趋势的思考

结合欧洲足球技战术的发展特点,就鲁能泰山足球队的体能训练、技术训练、防守阵型、进攻方式、定位球、职业态度、球星培养等诸方面所存在的不足进行了分析,提出相应的改进意见。