优秀散打运动员膝/肘关节等速测试与站位攻防技术分析

采用ISOMED2000等速系统检测优秀散打运动员膝、肘关节肌群的生物力学特征,分析优秀散打运动员站位攻防动作技术.在进攻训练中伸膝关节速度达到300°/s,能充分发挥运动员小腿伸肌群的爆发能力;采用300°/s的速度可以快速屈小腿,有利于运动员快速回防,为再次打击对方在时间上创造了条件;在站位时,膝关节角度保持157.3°～160.1°,小腿屈肌群离心爆发能力强,有利于运动员调整自身的身体姿势,避开对方的快速进攻.在进攻训练中应使肘关节速度达到300°/s,能充分发挥运动员前臂伸肌群的爆发能力.肘关节角度在81°～86°的范围,有利于运动员快速出拳,打击对方.以240°/s的速度屈肘,能充分发挥运动员前臂屈肌群的爆发能力,有利于运动员快速回防.在防守训练中,肘关节角度在78°～85°的范围内,对运动员快速回防,抵御时方快速、重拳的进攻是有利的;肘关节角度在128°～137°的范围内,可远距离隔挡对方,阻击对方的快速进攻.     

竞技武术套路运动员表现力的培养方法研究

竞技武术套路比赛中运动员的表现力起着越来越关键的作用。文章运用文献资料法、问卷调查法等研究方法,对影响竞技武术套路运动员表现力的各种因素进行了研究分析。研究结果表明：影响竞技武术套路运动员表现力的因素主要包括气质和性格、赛前心理准备、兴趣、表情和乐感,并针对这些因素对武术套路运动员表现力培养的方法进行了探讨,以指导训练工作。     

关于人类运动极限的哲学思考

北京奥运会上,博尔特以令人难以置信的速度打破了人类100 m世界纪录,又一次引发了关于人类运动极限的大讨论.在此背景下,在分析人类运动极限的两个相反观点基础上,认为:生理极限是人类运动极限有限论的理论基础;社会因素的时代性是人类运动极限无限论的理论基础;自然外力是制约运动极限的偶然性因素,只有在自然外力最大的基础上讨论人类运动极限才有实际意义;测不准原理决定了人们用数量方法预测人类运动极限的局限性;人类运动极限是有限性和无限性的统一.     

A method of providing accurate velocity feedback of performance on an instrumented kayak ergometer

On a kayak ergometer, an accurate simulation of the athlete-paddle-kayak system kinematics is essential for analysing the relationship between technique and performance. The purpose of this study was to establish a strong relationship between performances on flatwater and performances on an ergometer by means of propulsive force measurement and drag models. Two trials were performed by 12 kayakers in which they were first timed over 250 m of flatwater kayaking (the reference test) and were then asked to perform a trial of the same duration on the ergometer with the same perceived physical exertion. Three techniques for measuring propulsive force and three drag models generated nine combinations, which were all evaluated for their ability to estimate kayak velocity. For each combination, the distance covered by the athlete on the ergometer was simulated. A kayakers’ ergometer ranking was based on the average velocity in the ergometer trial. Both distance and ranking were compared to the on-water results. The simulation with the best combination of force measurement and drag model gave an accurate estimate of distance (253 ± 10.5 vs. 250 m) and ranking compared to the reference test.     

《费尔巴哈》中的"需要"思想解析

<费尔巴哈>是<德意志意识形态>第一章手稿的新编译本,"需要"是这部著作中的重要范畴.需要既受生产实践的制约,又推动生产实践的不断发展;需要推动分工的出现和发展又和分工一起推动了所有制形式的演变.需要是人的本性,是历史发展的原发驱动力.     

理性和意志碰撞的体育动力论

在进一步研究体育的本质问题时发现：理性制约意志驱动体育动力来源发生着碰撞,理性不是唯一的,意志也不是唯一的,彼此之间超越一方达到极至,将产生一种失衡状态,客观地存在着控制与反控制的动力平衡点,这个过程被人类社会秩序完整地掌握和调控。表现在：体育意志试图超越理性的界碑,但总是被限制;理性试图超越意志的体育灵魂,也经受到有力的打击;当理性制约意志的体育动力时,也发生着因果关系的转换。     

我国花样滑冰后备人才培养的途径

在对现阶段我国花样滑冰后备人才培养现状进行研究的基础上,分析花样滑冰后备人才培养的重要性,并对我国花样滑冰的运动员、教练员、科研人员后备人才的培养提出：加大宣传力度,改变观念;建立完善的业余训练体制;进一步发展“北冰南展”策略;建立有偿输送体制;体教结合,建立后备人才培养基地;建立完善的选拔、培养、考核机制;大力实施“送出去、引进来”等相关培养途径。     

影响我国男子甲级排球队团队凝聚力水平的因素研究

以卡伦提出的凝聚力概念模式理论为依据,对参加2006年全国男子排球锦标赛的16支甲级运动队的运动员进行问卷调查,分析影响男子排球运动队凝聚力问题的各种因素,为教练员与俱乐部管理人员对球队管理及运动员心理整合与共溶性提出相应的理论参考。研究结果表明,影响我国男子甲级排球运动队凝聚力水平的主要因素依次为协调因子、团结因子、素质因子、个体因子、稳定性因子、巩固性因子。     

Effects of oncoming target velocities on rapid force production and accuracy of force production intensity and timing

The present study aimed to clarify the effects of oncoming target velocities on the ability of rapid force production and accuracy and variability of simultaneous control of both force production intensity and timing. Twenty male participants (age: 21.0 ± 1.4 years) performed rapid gripping with a handgrip dynamometer to coincide with the arrival of an oncoming target by using a horizontal electronic trackway. The oncoming target velocities were 4, 8, and 12 m · s^?1, which were randomly produced. The grip force required was 30% of the maximal voluntary contraction. Although the peak force (Pf) and rate of force development (RFD) increased with increasing target velocity, the value of the RFD to Pf ratio was constant across the 3 target velocities. The accuracy of both force production intensity and timing decreased at higher target velocities. Moreover, the intrapersonal variability in temporal parameters was lower in the fast target velocity condition, but constant variability in 3 target velocities was observed in force intensity parameters. These results suggest that oncoming target velocity does not intrinsically affect the ability for rapid force production. However, the oncoming target velocity affects accuracy and variability of force production intensity and timing during rapid force production.     

Kinematic and kinetic analysis of overhand,sidearm and underhand lacrosse shot techniques

Lacrosse requires the coordinated performance of many complex skills. One of these skills is shooting on the opponents’ net using one of three techniques: overhand, sidearm or underhand. The purpose of this study was to (i) determine which technique generated the highest ball velocity and greatest shot accuracy and (ii) identify kinematic and kinetic variables that contribute to a high velocity and high accuracy shot. Twelve elite male lacrosse players participated in this study. Kinematic data were sampled at 250 Hz, while two-dimensional force plates collected ground reaction force data (1000 Hz). Statistical analysis showed significantly greater ball velocity for the sidearm technique than overhand (P < 0.001) and underhand (P < 0.001) techniques. No statistical difference was found for shot accuracy (P > 0.05). Kinematic and kinetic variables were not significantly correlated to shot accuracy or velocity across all shot types; however, when analysed independently, the lead foot horizontal impulse showed a negative correlation with underhand ball velocity (P = 0.042). This study identifies the technique with the highest ball velocity, defines kinematic and kinetic predictors related to ball velocity and provides information to coaches and athletes concerned with improving lacrosse shot performance.