Cycling shoe aerodynamics

The present paper describes the activity carried out to investigate the aerodynamic effects of cycling shoes for time trial competitions. This subject has not been widely studied but can be important for an accurate aerodynamic optimisation of a time trial cyclist. The study was carried out by means of wind tunnel testing: an appropriate test setup and an appropriate test procedure (based on “effective angle of attack approach”) were developed in order to produce realistic test conditions. The developed testing procedure was applied to two different shoe models, differently fastened. Furthermore, an important point was the investigation of the overshoe effect. The results showed that the power required to overcome the shoe’s drag is almost a tenth of the total power and that differences between the shoes can affect the cyclist’s performance.     

大学生羽毛球运动员的应激现状与分析

运用文献资料、专家访谈、问卷调查、心理测量和数理统计等方法,对我国259名大学生羽毛球运动员运动心理应激与运动成绩的关系进行研究。研究结果表明：（1）男运动员比女运动员的运动应激多,男女运动员的应激多数都集中在比赛中的突发事件这一应激源中;（2）在人际关系和环境因素中女运动员比男运动员的应激多;（3）除健将级和一级运动员外,其他运动员等级越高应激刺激越大。     

我国高校羽毛球的实力布局

运用文献资料法和数理统计法等方法,分析第9～12届全国大学生羽毛球锦标赛参赛队及成绩,了解目前我国高校羽毛球的发展及其布局动态,以期提高我国大学生羽毛球的水平、推动高校羽毛球运动的发展.结果表明:在各单项成绩上,在男子、女子项目上,都出现男女实力不均的现象;各等级区域间存在漂移规律,第一区域比较稳定,第二、三区域漂移明显.     

羽毛球教学中的步法移动技术

羽毛球步法是羽毛球运动各项技术的基础，是羽毛球正确击球手法的前提和保证。结合多年的教学实践，分析了羽毛球步法的组成、结构、分类、教学手段和方法等。     

青少年羽毛球运动员体能训练

从力量、速度、耐力、灵敏和柔韧等素质训练方面,探讨青少年羽毛球运动员体能训练方法及应注意的问题.认为:青少年羽毛球运动员处在体能训练和储备的最佳时期,需抓住各项素质发展的窗口期着力提升综合能力.     

Physiological characteristics of elite and sub-elite badminton players

Abstract

The aims of this study were to establish the physical and physiological attributes of elite and sub-elite Malaysian male badminton players and to determine whether these attributes discriminate elite players from sub-elite players. Measurements and tests of basic anthropometry, explosive power, anaerobic recovery capacity, badminton-specific movement agility, maximum strength, and aerobic capacity were conducted on two occasions, separated by at least one day. The elite (n = 12) and sub-elite (n = 12) players' characteristics were, respectively: mean age 24.6 years (s = 3.7) and 20.5 years (s = 0.7); mass 73.2 kg (s = 7.6) and 62.7 kg (s = 4.2); stature 1.76 m (s = 0.07) and 1.71 m (s = 0.05); body fat 12.5% (s = 4.8) and 9.5% (s = 3.4); estimated VO_2max 56.9 ml · kg^?1 · min^?1 (s = 3.7) and 59.5 ml · kg^?1 · min^?1 (s = 5.2). The elite players had greater maximum absolute strength in one-repetition maximum bench press (P = 0.015) compared with the sub-elite players. There were significant differences in instantaneous lower body power estimated from vertical jump height between the elite and sub-elite groups (P < 0.01). However, there was no significant difference between groups in shuttle run tests and on-court badminton-specific movement agility tests. Our results show that elite Malaysian male badminton players are taller, heavier, and stronger than their sub-elite counterparts. The test battery, however, did not allow us to discriminate between the elite and sub-elite players, suggesting that at the elite level tactical knowledge, technical skills, and psychological readiness could be of greater importance.     

Measurement of badminton racket deflection during a stroke

The compliance of a badminton racket is an important design consideration, which can be better understood by studying the deflection behaviour of the racket during a stroke. Deflection can be measured using direct methods, such as motion capture or high speed video, or by indirect methods, which then require a mathematical model in order to calculate the deflections from indirect measures. Indirect methods include strain gauges and accelerometers. Here, racket deflection is measured directly using motion capture and compared with deflections calculated from strain gauge data using a beam model. While the elastic behaviour is better calculated from strains than measured by motion capture, it is not possible to extract the whole motion of the racket from strain data. Motion capture is therefore also necessary to determine the rigid body velocity, in order to put the elastic velocity (as calculated from strains) in perspective.     

Effects of forefoot bending stiffness of badminton shoes on agility,comfort perception and lower leg kinematics during typical badminton movements

This study investigated whether an increase in the forefoot bending stiffness of a badminton shoe would positively affect agility, comfort and biomechanical variables during badminton-specific movements. Three shoe conditions with identical shoe upper and sole designs with different bending stiffness (Flexible, Regular and Stiff) were used. Elite male badminton players completed an agility test on a standard badminton court involving consecutive lunges in six directions, a comfort test performed by a pair of participants conducting a game-like practice trial and a biomechanics test involving a random assignment of consecutive right forward lunges. No significant differences were found in agility time and biomechanical variables among the three shoes. The players wearing the shoe with a flexible forefoot outsole demonstrated a decreased perception of comfort in the forefoot cushion compared to regular and stiffer conditions during the comfort test (p < 0.05). The results suggested that the modification of forefoot bending stiffness would influence individual perception of comfort but would not influence performance and lower extremity kinematics during the tested badminton-specific tasks. It was concluded that an optimisation of forefoot structure and materials in badminton shoes should consider the individual’s perception to maximise footwear comfort in performance.     

Fundamental aerodynamics of the soccer ball

When the boundary layer of a sports ball undergoes the transition from laminar to turbulent flow, a drag crisis occurs whereby the drag coefficient (C _d) rapidly decreases. However, the aerodynamic properties and boundary-layer dynamics of a soccer ball are not yet well understood. In this study we showed that the critical Reynolds number (Re _crit) of soccer balls ranged from 2.2 × 10⁵ to 3.0 × 10⁵. Wind-tunnel testing, along with visualisation of the dynamics of the boundary layer and the trailing vortex of a ball in flight, demonstrated that both non-spinning and spinning (curved) balls had lowC _d values in the super-critical region. In addition, theRe _crit values of the soccer balls were lower than those of smooth spheres, ranging from ∼ 3.5 × 10⁵ to 4.0 × 10⁵, due to the effects of their panels. This indicated that the aerodynamic properties of a soccer ball were intermediate between those of a smooth ball and a golf ball. In a flow visualisation experiment, the separation point retreated and theC _d decreased in a super-critical regime compared with those in a sub-critical regime, suggesting a phenomenon similar to that observed in other sports balls. With some non-spinning and spinning soccer balls, the wake varied over time. In general, the high-frequency component of an eddy dissipated, while the low-frequency component increased as the downstream vortex increased. The causes of the large-scale fluctuations in the vortex observed in the present study were unclear; however, it is possible that a ‘knuckle-ball effect’ of the non-rotating ball played a role in this phenomenon.     

多媒体技术在高校羽毛球教学中的应用

运用文献法、对比实验法、问卷调查法和数理统计法,对高校羽毛球选项课进行教学实验对比,创新多媒体技术在羽毛球教学中的应用。结果表明：多媒体组合教学法与单一的传统教学法相比,有其独特的优越性,符合高校羽毛球教学特点和教学目标,不仅更易激发学生的主观能动性,更快建立完整、正确的动作表象,更好掌握技术动作要领,提高教学效果;而...     

大学生羽毛球运动员赛前情绪与心理准备

羽毛球运动员成绩的优劣,不仅取决于临场技战术的发挥水平,而且取决于赛前情绪与心理准备的程度。对大学生羽毛球运动员赛前情绪状态及其产生的原因进行了分析,提出了运动员赛前心理准备的内容及赛前心理状态的调节方法,旨在对赛前运动员的心理指导提供帮助。     

国外羽毛球协会管理体制的历史演进与运行特征

在描述国外羽毛球协会制度变迁过程的基础上,分析了羽毛球协会管理效能的本质特征,认为世界各国羽毛球协会具有非营利特性,重视为会员提供服务,项目管理采取民主管理方式,组织之间强调互利合作关系。我国羽毛球协会管理体制改革应借鉴国外的普适性经验,处理好政府机构和协会之间的关系,进一步完善中国羽毛球协会的管理体制。     

湖南省业余羽毛球学校发展现状

运用文献资料、问卷调查及数理统计等方法,对湖南省业余羽毛球学校的分布情况、教师及教练员基本情况、学生的基本情况、教学基本情况以及与全民健身活动开展情况进行调查研究.并针对发展现状和存在的问题,提出相应的发展对策.     

Investigation of high-speed badminton racket kinematics by motion capture

The kinematics of a badminton racket during a smash stroke was observed in this study with the purpose of investigating stroke dynamics and racket behaviour. Motion capture measurements of the racket during several smash strokes performed by three players of different skill levels indicated a clear increase in racket velocity at impact with increasing skill level. Variations between translational and rotational contributions to the impact speed could also be seen between the players. The advanced player produced a much higher peak angular velocity and also relied much less on translation, with a translational velocity of only 8% of the total velocity versus the 20% for the recreational player. It is proposed that, as an alternative to shuttlecock speeds, racket head speed measurements can be used as an indicator of performance, and can also provide some insight into the interaction between the racket and player.     

运动预期与羽毛球运动水平的相关研究

运动专家的预期优势已被大量研究证实,然而在解释为何专家具有预期优势的问题上出现了分歧.主要原因是传统研究在概念上混淆了预期反应和动作选择反应,无法揭示运动预期与运动水平相关本质.运用图像定格技术,在实验技术上清晰分离预期反应和动作选择反应.并借鉴"专家-新手"研究范式,探讨羽毛球竞赛情景中运动预期与运动水平的相关本质.发现运动专家的预期优势主要表现在预期正确率上,预期反应时并无优势.正确预期显著缩短运动行为选择反应时,错误预期显著延长运动行为选择反应时.     

少儿羽毛球运动员的心理特征及其训练

注重少儿羽毛球运动员的心理训练,是培养高水平羽毛球运动员的必备条件之一.其重要性决不亚于任何技战术训练和身体素质训练.文章通过对少儿心理特点、个性心理特征、心理的一般概念进行研究,并以此为依据提出了一些有关提高羽毛球运动员心理能力的训练方法.     

南宁市羽毛球场馆体育消费的调查与分析

采用文献法、调查法、数理统计法,对南宁市羽毛球场馆的体育消费进行了研究.结果表明：场馆体育消费主要集中在青年人、中年人以及文化程度较高、职业稳定、中高收入水平的人群;其体育消费动机体现出趋同性,各年龄段的侧重点不同;大多数人了解羽毛球运动,有持久兴趣,但满足于业余爱好,接受专业指导的需求较弱;人群主要以随机方式到场馆进行消费为主,一半人每周到场馆消费2至3次;从消费的频率、规模等方面看,南宁市羽毛球运动的体育消费相对稳定且已具规模;消费结构以实物形式的消费资料为主,服务形式的消费资料比例较小,精神产品形式的消费资料有一定需求.     

3V3羽毛球赛事发展前景分析

3v3羽毛球赛事作为一种新兴的业余体育赛事,在我国已形成了广泛的群众基础和广阔的发展前景。本文以3v3羽毛球赛事发展的现状作为研究对象,通过文献、逻辑分析等方法对3v3羽毛球赛事发展现状进行简述,明晰其发展优势和困境,并提出适合3v3羽毛球赛事发展的亲民化、协同化和品牌化发展策略,为3v3羽毛球赛事发展提供参考。     

羽毛球竞赛女双项目的制胜规律

在羽毛球界传统观念中,没有正确认识技术风格与制胜规律的关系,因而推导出现代女双正朝着“拉开、调动突击”方向发展的论断。分析两对奥运会女双冠军的一场经典比赛的技术数据,并借鉴男双项目的发展规律,深入探讨女双项目的制胜规律：(1)中国特色的羽毛球技术风格,无论单打、双打,集中体现在“快、狠、准、活”4个字上。其中“快”字为核心,其它3个方面都是“快”的具体表现。对于不同的单项,“快”的具体表现不同。(2)1978年羽毛球训练工作会议所提出的“快、狠、平、近、压”的双打指导思想是对技术风格的一个不完整表述。(3)羽毛球项目制胜的核心因素是“快”,影响“快”的因素有“狠、准、活”。三者统一在“快”的基础上,在综合形成“快”的过程中,表现出总和律、突前律和更迭律。女双项目同样遵循这一规律。     

A biomechanical analysis of common lunge tasks in badminton

Abstract

The lunge is regularly used in badminton and is recognized for the high physical demands it places on the lower limbs. Despite its common occurrence, little information is available on the biomechanics of lunging in the singles game. A video-based pilot study confirmed the relatively high frequency of lunging, ～15% of all movements, in competitive singles games. The biomechanics and performance characteristics of three badminton-specific lunge tasks (kick, step-in, and hop lunge) were investigated in the laboratory with nine experienced male badminton players. Ground reaction forces and kinematic data were collected and lower limb joint kinetics calculated using an inverse dynamics approach. The step-in lunge was characterized by significantly lower mean horizontal reaction force at drive-off and lower mean peak hip joint power than the kick lunge. The hop lunge resulted in significantly larger mean reaction forces during loading and drive-off phases, as well as significantly larger mean peak ankle joint moments and knee and ankle joint powers than the kick or step-in lunges. These findings indicate that, within the setting of this investigation, the step-in lunge may be beneficial for reducing the muscular demands of lunge recovery and that the hop lunge allows for higher positive power output, thereby presenting an efficient lunging method.