从第27届奥运会体操比赛看世界男子跳马发展趋势

采用录像观察、查阅文献资料等方法，对第27届奥运会男子体操跳马决赛运动员的动作起评分与完成情况进行了研究，结合近2年世界体操大赛获跳马奖牌运动员的相关材料，分析了当今世界男子跳马的发展趋势。结果表明，掌握“双10分”起评动作是跳马比赛发展的明显趋向，提高动作成功率是跳马比赛取胜的条件，确保落地稳定是跳马比赛夺冠的关键。     

我国男子跳马运动的现状与存在的问题——析第八届全运会男子跳马比赛

采用现场观摩与统计相结合的方法,对第八届全运会男子跳马预赛情况进行分析。结果显示,跳马比赛中,运动员的动作难度大,欲取得好成绩,必须有拿手的10分起评动作;另外,动作类型单一,多集中在侧手翻类,这不利于跳马运动的发展。     

从第10 届全运会看我国男子跳马难新动作的发展趋势

采用调查访问、录像观察和文献资料等方法，对第10届全运会和第28届奥运会体操比赛男子跳马单项决赛前8名运动员的动作类型、动作难度及完成情况进行统计，分析我国男子跳马项目难度发展的现状，剖析我国男子跳马发展难新动作的有利条件，提出今后几年我国男子跳马难新动作的发展方向。     

我国男子跳马难度与创新的研究

<正> 我国第六届全运会体操比赛于1987年先后在上海和深圳进行了预赛和决赛,跳马在第六届全运会的体操比赛中是一个引人注目的精彩项目,在自选动作的跳马比赛中,楼云独得了全运会体操比赛仅有的两个10分。但纵观跳马比赛的全局,尚有不少问题有待进一步探讨,本文仅对我国男子跳马的难度与创新进行研究。     

当今世界男子跳马发展趋向的断想

采用录像跟踪与数理统计法 ,对’ 99世界体操锦标赛男子四个种类比赛中的跳马动作起评分与完成情况进行分析。结果表明 :运动员选择 10分起评动作呈集中化趋向。比赛中 ,努力完成高起评分动作并力求使完成情况少失分是运动员提高完成动作效能获取高分的直接思考点。跳马单项决赛中 ,跳“双 10分”起评动作 ,注重“保一争二”的训练策略是当今世界男子跳马夺牌或夺冠的必然选择。     

2000年全国体操锦标赛男子跳马比赛调研与分析

采用现场统计与文献资料法对2000年全国体操锦标赛参加跳马比赛运动员的动作类型、起评分与完成情况等相关指标进行了分析,并结合1999年天津世界体操锦标赛与1999年全国体操锦标赛跳马比赛情况进行了对比研究。结果表明,我国男子跳马的整体实力处于世界较高水平;李晓鹏与肖俊峰两名运动员的2跳动作都为10分起评,而且完成质量好,是目前我国乃至世界男子跳马最优秀的运动员。虽然我国有较多运动员能掌握10分起评,但完成前团2周这一“潮流动作”的人数不算太多,完成情况的姿态、高度与落地环节的整体规格不太高。建议今后训练中对动作姿态与高度应高要求,把落地环节作为高水平跳马运动员的训练重点。     

跳马运动员落地技术训练方法

解析跳马落地技术生物学原理,对比我国跳马运动员与国外优秀选手的动作差异。认为:难度和落地成功率是取得跳马佳绩的决定因素;应着重分析跳马项目落地缓冲动作;提出跳马运动员落地技术的训练举措;我国跳马项目在世界大赛上缺乏竞争力。     

从37届和40届世锦赛看男子体操跳马动作发展趋势

以40届体操世锦赛为资料对世界男子体操跳马比赛的发展趋势进行了研究,结果表明：近几年世界体操大赛国际男子跳马动作难度有极快的提高,跳马的难度还体现出跳马正在向着多类型和多轴转体的方向发展,但完成跳马动作的稳定性是一成不变的,在同等难度下跳马落地稳定性好的选手,还是一个当前男子跳马制胜的法宝。     

从37届和40届世锦赛看男子体操跳马动作发展趋势

以40届体操世锦赛为资料对世界男子体操跳马比赛的发展趋势进行了研究,结果表明:近几年世界体操大赛国际男子跳马动作难度有极快的提高,跳马的难度还体现出跳马正在向着多类型和多轴转体的方向发展,但完成跳马动作的稳定性是一成不变的,在同等难度下跳马落地稳定性好的选手,还是一个当前男子跳马制胜的法宝。     

第27届奥运会世界男子跳马运动发展态势分析

采用调查访问法、录像统计法和资料研究法对第33届、34届世界体操锦标赛和第27届奥运会男子跳马比赛前8名运动员的比赛成绩、动作难度及完成情况进行了统计并与中国队进行了对比与研究。结果表明：男子跳马高难动作的类型趋于多样性,前手翻团身前空翻两周半和冢原团身后空翻2周是当今跳马所采用的两个主要动作;要夺取跳马比赛的金牌,两跳的起评分均需达到10分起评。随着运动水平的提高,越来越多的运动员掌握了双10分起评的不同类型动作,但运动员落地的稳定性仍不高。     

田径速度力量项群运动负荷控制特征的研究

运用文献资料法、特征解析法和数理统计等方法,对田径速度力量项群运动负荷控制特征进行研究。研究揭示,多年训练过程中一般身体素质和基本技术训练所占比重,随着训练年限和竞技能力增长而趋于递减,但专项身体素质和专项技术训练所占比重则趋于递增。年度训练过程中的准备期训练重点集中在发展绝对力量、速度力量和专项技术训练等方面,负荷变化表现为负荷量和负荷强度几乎平行发展并呈现出渐进性递增特征,其中负荷强度一般控制在80%-90%最高成绩水平上。比赛期的负荷量约下降20%,但负荷强度上升10%。而过渡期则表现出负荷量和负荷强度同时下降的特征。小周期训练过程中的赛前小周期负荷变化表现为负荷量有所降低但负荷强度却有所增加的特征,而且负荷强度在赛前2周左右达到最高水平,其中大强度训练的持续时间约为10.5天-21天,其比例约占赛前训练总负荷的10%-30%左右,最后一次大强度训练高峰出现的时间一般距离比赛日之前5天-12天。     

从十运会看我国男子体操运动的现状与发展——谈北京奥运会备战思路

通过现场观察、调查访问和文献资料等方法,对全国第10届运动会男子体操全能、单项前8名运动员的比赛成绩、动作难度及完成情况进行了统计分析和研究.结果表明:在各项目高起评分下的成功率将成为比赛的关键,全能比赛在6个项目均衡发展的前提下要求突出更多强项:单项比赛更加突出了"特长性".十运会也涌现出了一批具有潜力的体操新秀,为备战北京奥运会提供了人选思路.     

Engineering the race car wing: application of the vortex panel numerical method

This study examined aerodynamic properties and boundary layer stability in five cambered airfoils operating at the low Reynolds numbers encountered in motor racing. Numerical modelling was carried out in the flow regime characterised by Reynolds numbers 0.82–1.29 × 10⁶. The design Reynolds number of 3 × 10⁶ was used as a reference. Aerodynamics variables were computed using AeroFoil 2.2 software, which uses the vortex panel method and integral boundary layer equations. Validation of AeroFoil 2.2 software showed very good agreement between calculated aerodynamic coefficients and wind tunnel experimental data. Drag polars, lift/drag ratio, pitching moment coefficient, chordwise distributions (surface velocity ratio, pressure coefficient and boundary layer thickness), stagnation point, and boundary layer transition and separation were obtained at angles of attack from −4° to 12°. The NASA NLF(1)-0414F airfoil offers versatility for motor racing with a wide low-drag bucket, low minimum profile drag, high lift/drag ratio, laminar flow up to 0.7 chord, rapid concave pressure recovery, high resultant pressure coefficient and stall resistance at low Reynolds numbers. The findings have implications for the design of race car wings.     

Relationship of the AAHPER Youth Fitness Test to Total Dynamic Strength

Abstract

One hundred high school girls (N = 20 per group) were initially given 10 trials on the Bachman ladder-climb task; each group was given a different length of lay-off (10 min., or 1 day, or 1 week, or 4 weeks, or 13 weeks) before being retested with another 10 trials. Correlations between individual differences across the lay-off decreased as the length of the lay-off period increased (from r = .89 to r = .69). Correlations between adjacent trials remained relatively constant at r =.90 as practice progressed. As remoteness increased, the relation decreased regularly, from r =.92 to r =.68. Individuals became increasingly different from each other as a result of motor learning; intraindividual variance did not change appreciably.     

Consistency of performances in the Tkatchev release and re-grasp on high bar

The Tkatchev on the high bar is a release and re-grasp skill in which the gymnast rotates in a direction during flight opposite to that of the preceding swing. Since the release window is defined as the time during which the gymnast has appropriate linear and angular momentum to ensure the bar can be re-grasped, it was speculated that the release windows for this skill would be smaller than for dismounts that are less constrained. One senior male gymnast competing at national standard performed 60 Tkatchev trials. A four-segment planar simulation model of the gymnast and high bar was used to determine the release windows in 10 successful and 10 unsuccessful performances of the Tkatchev recorded using a Vicon motion analysis system. Model parameters were optimized to obtain a close match between simulations and recorded performances in terms of rotation angle (1 degree), bar displacements (0.01 m), and release velocities (1%). Each matched simulation was used to determine the time window around the actual point of release for which the model had appropriate release parameters to complete the Tkatchev successfully. The release windows for the successful trials were small compared with those of dismounts. The unsuccessful trials were associated with later release and later timing of the actions at the shoulders and hips.     

Effect of different velocity loss thresholds during a power-oriented resistance training program on the mechanical capacities of lower-body muscles

This study compared the effects of two velocity loss thresholds during a power-oriented resistance training program on the mechanical capacities of lower-body muscles. Twenty men were counterbalanced in two groups (VL10 and VL20) based on their maximum power capacity. Both groups used the same exercises, relative intensity and repetition volume, only differing in the velocity loss threshold of each set (VL10: 10% vs. VL20: 20%). Pre- and post-training assessments included an incremental loading test and a 15-m linear sprint to assess the force- and load-velocity relationships and athletic performance variables, respectively. No significant between-group differences (P > 0.05) were observed for the force-velocity relationship parameters (ES range = 0.15–0.42), the MPV attained against different external loads (ES range = 0.02–0.18) or the 15-m sprint time (ES = 0.09). A high between-participants variability was reported for the number of repetitions completed in each training set (CV = 30.3% for VL10 and 29.4% for VL20). These results suggest that both velocity loss thresholds induce similar changes on the lower-body function. The high and variable number of repetitions completed may compromise the velocity-based approach for prescribing and monitoring the repetition volume during a power-oriented resistance training program conducted with the countermovement jump exercise.     

Consistency of performances in the Tkatchev release and re-grasp on high bar

The Tkatchev on the high bar is a release and re-grasp skill in which the gymnast rotates in a direction during flight opposite to that of the preceding swing. Since the release window is defined as the time during which the gymnast has appropriate linear and angular momentum to ensure the bar can be re-grasped, it was speculated that the release windows for this skill would be smaller than for dismounts that are less constrained. One senior male gymnast competing at national standard performed 60 Tkatchev trials. A four-segment planar simulation model of the gymnast and high bar was used to determine the release windows in 10 successful and 10 unsuccessful performances of the Tkatchev recorded using a Vicon motion analysis system. Model parameters were optimized to obtain a close match between simulations and recorded performances in terms of rotation angle (1°), bar displacements (0.01 m), and release velocities (1%). Each matched simulation was used to determine the time window around the actual point of release for which the model had appropriate release parameters to complete the Tkatchev successfully. The release windows for the successful trials were small compared with those of dismounts. The unsuccessful trials were associated with later release and later timing of the actions at the shoulders and hips.     

第九、十届全运会奖牌榜前八名奖牌走向和项目分布特征研究

采用数理统计法和资料研究法，对第九、十届全运会前8名运动队获得的奖牌情况进行了对比分析。结果表明：前8名奖牌分布呈现出均衡性和优势项目覆盖的广泛性，金牌数和获得奖牌的项数具有高度的相关性，十运会奖牌数和奖牌项的比值均比九运会有所提升；优势项目和优势项目奖牌数的相关系数为0．711。奖牌的分布表现出项目的集中性和明显的地域性特征；奥运会奖牌带人全运会的记分办法对前8名排序的影响呈现出一定的规律性，但影响不明显。     

Growth influences biomechanical profile of talented swimmers during the summer break

This study aimed to analyse the effect of growth during a summer break on biomechanical profile of talented swimmers. Twenty-five young swimmers (12 boys and 13 girls) undertook several anthropometric and biomechanical tests at the end of the 2011–2012 season (pre-test) and 10 weeks later at the beginning of the 2012–2013 season (post-test). Height, arm span, hand surface area, and foot surface area were collected as anthropometric parameters, while stroke frequency, stroke length, stroke index, propelling efficiency, active drag, and active drag coefficient were considered as biomechanical variables. The mean swimming velocity during an all-out 25 m front crawl effort was used as the performance outcome. After the 10-week break, the swimmers were taller with an increased arm span, hand, and foot areas. Increases in stroke length, stroke index, propelling efficiency, and performance were also observed. Conversely, the stroke frequency, active drag, and drag coefficient remained unchanged. When controlling the effect of growth, no significant variation was determined on the biomechanical variables. The performance presented high associations with biomechanical and anthropometric parameters at pre-test and post-test, respectively. The results show that young talented swimmers still present biomechanical improvements after a 10-week break, which are mainly explained by their normal growth.     

力量训练对高中100米项目特长生专项成绩的影响分析——以滕州二中为例

高中生现阶段正处于身体的发育期,如何在这一阶段强化百米项目特长生的整体训练,提升整体成绩,成为高中短距离跑步项目教练员不断思考的问题。现阶段,在百米特长生专项训练中,整体过于关注成绩本身,忽视了专项力量训练对于特长生的意义。基于此,本文以滕州市第二中学30名体育特长生做为实验对象,以专项力量训练对100M跑中对成绩的影响因素为研究内容,将其分成实验组和对照组,每组各15人,进行为期10周内训练的成果进行测试,对测试的结果进行分析,发现力量训练与高中100米项目特长生专项成绩之间的关系。