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本文通过对我国部分优秀棒球选手的挥击动作运动学和动力学的分析，力图描述出我国棒球选手目前挥击动作中髋、肩、腕等关节的运动状态和它们与甜点之间协调制约的关系，以及挥击技术动作中上述有关环节及时制动的生物力学原理及其应用价值。 相似文献
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通过观察上海女子垒球队的训练以及全国垒球联赛,再结合自身的经验,在挥击直线快球和变化球的下肢及转体动作,有许多相同点也有它们之间的区别。下面我们就具体进行分析它们的共同点与区别以及容易出现的错误动作。1、挥击内角直线快球的下肢及转体动作在挥击内角直线快球的动作中,主要强调的是一个＂快＂字。是指腰部及下肢的蹬地转体动作要快。 相似文献
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2.挥击幅度变化大幅度的挥击在菲律宾武技流派中通常称为长弧线攻击(图60～64)。其特点是挥击动作的幅度(半径)一直以最大值的形式贯穿于整个动作的始终,常见于较长或较重武器的使用中,其幅度的增大是由于持械手臂受到挥击动作时产生的离心力或武器重量过大造成的。一般来说,长弧线攻击只用于攻防训练中,以放慢速度的形式给练习者提供更多的反 相似文献
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击球时充分利用下身的力量 阿加西的击球动作特点就是快而有力地挥拍以及较大的随挥动作。无论是对慢速球还是对快速球,阿加西的随挥动作都比较大。此外,他的击球瞬间的向内翻手腕对控制球也很有好处。 大的随挥动作可以有利于将击出的球压住。如果有意识地提高挥拍的速度,随挥动作自然也就比较大。此外,还要注意将下身力量作用到击球瞬间,在挥拍时利用身体的转动可以增加击球的力量。 相似文献
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正手上旋球的随挥，它是击球后的一个结束动作，也称跟进。在实践中，多有初学者和一般水平的人认为击球时的随挥不重要，从而产生各种错误动作。那么对随挥的错误见解及错误动作究竟有哪些?产生原因如何?随挥在击正手上旋球时的主要作用及注意问题何在呢?本文拟就上述问题发表一点掘见，愿与同行进行讨论。 相似文献
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挥击击球是垒球运动中难度较大的基本技术之一,也是垒球比赛中进攻得分,主动制胜对方的重要手段。挥击击球的效果如何,在很大程度上反映全队进攻实力的强弱,在一些重大比赛中,它往往对全队战绩的高低起着相当重要的作用。因此,掌握好击球技术,提高击球效果,对每个垒球运动员来说都是非常必要 相似文献
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张昌亨 《武汉体育学院学报》1989,(1)
棒、垒球运动员击球的好坏,除了与挥击动作技术有关外,还与棒击球的打击点有密切关系。若动作正确,打击点不好,则会产生震手的感觉,击出的球沉而不远。本文就棒击球的打击点,从理论和实验上作了系统分析,阐明产生震手的原因和危害,消除震手作用的力学条件,并用实例说明消除震手的原因。本文还以日制金属棒为对象,实验测得各种棒、垒球最佳打击点,为运动员使用球棒击球提供了可靠依据。 相似文献
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郭坚 《体育科技文献通报》2009,17(12):53-55
从生物力学的角度,对网球正手击球的动作效果进行分析与评价。通过对正手击球动作的上肢引拍、躯干转动、下肢蹬伸肌群工作特点的分析,认为网球正手击球效果与动作速度、动作方向、动作时间、动作幅度有直接的关系。 相似文献
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The speed at which a player can swing a bat is central to the games of baseball and softball, determining, to a large extent,
the hit speed of the ball. Experimental and analytical studies of bat swing speed were conducted with particular emphasis
on the influence of bat moment of inertia on swing speed. Two distinct sets of experiments measured the swing speed of colege
baseball and fast-pitch softball players using weighted rods and modified bats. The swing targets included flexible targets,
balls on a tee and machine pitched balls. Internal mass alterations provided a range of inertial properties. The average measured
speeds, from 22 to 31 m s−1, are consistent with previous studies. Bat speed approximately correlates with the moment of inertia of the bat about a vertical
axis of rotation through the batter's body, the speed generally decreasing as this moment of inertia increases. The analytical
model assumes pure rotation of the batter/bat system about a vertical axis through the batter's body. Aerodynamic drag of
the batter's arms and the bat is included in the model. The independent variable is bat moment of inertia about the rotation
axis. There is reasonable agreement between the model and the measured speeds. Detailed differences between the two suggest
the importance of additional degrees of freedom in determining swing speed. 相似文献
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Field and laboratory measurements of softball player swing speed and bat performance 总被引：1，自引：1，他引：0
The swing speed of the bat is one of the most important factors affecting the hit-ball speed. Most field studies tend to focus on measuring ball speed, which is easier to measure and quantify than bat speed. For this reason, relatively little data exist describing bat motion in field conditions. The following describes a relatively large swing speed field study involving bats of the same model with nearly constant weight and varying inertia. The study was conducted using right-handed batters on a regulation outdoor field with a live pitcher. Swing speed was measured by tracking markers on the bat with two high-speed video cameras so that the bat markers could be traced in three-dimensional space. The ball motion was tracked using the same high-speed video cameras and a three-dimensional Doppler radar system. Bat swing speed was observed to be proportional to the batter skill level and the normalised swing speed increased with decreasing bat inertia. The bat centre of rotation during impact was close to the knob of the bat. The bats were tested under controlled laboratory conditions using a standardised performance test. The field and laboratory results showed good agreement including the hit-ball speed and the subtle effect of bat inertia on the maximum performance location. The vibrational response of the bats was considered using modal analysis. The maximum performance location was correlated with the node of the first vibrational mode. 相似文献
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王金连 《哈尔滨体育学院学报》2012,(5):86-89
网球是一项技术性强,技术要求细腻、速度快、变化多、学习难度大的运动项目。传统的网球教学准备活动普遍采用热身锻炼操,但其在促进学生运动技能掌握方面意义不大,笔者通过多年实践摸索、检验发现＂空手挥拍＂作为准备活动在网球教学中具有独特的优势。本文采用对比分析法,将空挥拍动作与传统热身锻炼操进行比较,提炼各自优缺点及对教学效果的影响。认为以＂空手挥拍＂取代传统的热身操,有助于学生形成肌肉记忆,更快提高网球技术。 相似文献
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Batter swing speed is an important parameter in understanding the performance of baseball and softball players. A number of swing speed sensors have recently been introduced and are commercially available. The aim of this study was to compare three wireless swing sensors with high speed video. Swing speed from high speed video was measured by differentiating the position coordinates of tracking markers on the bat barrel. On average, the wireless bat swing sensors reported speeds 8% slower than that found from video tracking. The agreement was better at low swing speeds, suggesting that the current generation of wireless sensors is best suited for developing players. Spatial measures, such as swing angle, were not in good agreement with video tracking. 相似文献
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Walter A. Laughlin Kyle T. Aune Alek Z. Diffendaffer 《Sports biomechanics / International Society of Biomechanics in Sports》2016,15(1):36-47
Swing trajectory and ground reaction forces (GRF) of 30 collegiate baseball batters hitting a pitched ball were compared between a standard bat, a bat with extra weight about its barrel, and a bat with extra weight in its handle. It was hypothesised that when compared to a standard bat, only a handle-weighted bat would produce equivalent bat kinematics. It was also hypothesised that hitters would not produce equivalent GRFs for each weighted bat, but would maintain equivalent timing when compared to a standard bat. Data were collected utilising a 500 Hz motion capture system and 1,000 Hz force plate system. Data between bats were considered equivalent when the 95% confidence interval of the difference was contained entirely within ±5% of the standard bat mean value. The handle-weighted bat had equivalent kinematics, whereas the barrel-weighted bat did not. Both weighted bats had equivalent peak GRF variables. Neither weighted bat maintained equivalence in the timing of bat kinematics and some peak GRFs. The ability to maintain swing kinematics with a handle-weighted bat may have implications for swing training and warm-up. However, altered timings of kinematics and kinetics require further research to understand the implications on returning to a conventionally weighted bat. 相似文献
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Hitting a major league fastball, with approximately half a second to react, poses one of the greatest challenges in sports.
The ability to hit the ball derives from the dynamics of the bat swing which can be measured using video motion capture. However,
doing so necessitates swinging the bat within the confines of a motion capture laboratory, often with considerable time and
expense. This paper introduces an inexpensive and highly portable measurement method for use right on the field of play to
support player training, coaching, rehabilitation, and player-bat fitting. The method employs a highly miniaturized, wireless
MEMS inertial measurement unit (IMU) affixed to the knob of the bat. The IMU incorporates three-axis sensing of bat acceleration
and angular velocity with a low-power RF transceiver to transmit this data to a host computer. Analysis of this data yields
a near-instantaneous and highly resolved summary of three-dimensional bat dynamics. This paper describes this novel technology
for use in baseball and softball, presents example results, and reveals new features of bat motion overlooked in previous
studies. 相似文献
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The purpose of this study was to determine if warm-up with baseball bats of different moments of inertia has an effect on swing pattern and bat velocity. Ten experienced baseball players (ages 20-25 years) voluntarily participated in this study. Each participant was required to complete 10 dry swings (5 warm-up and 5 postwarm-up) at maximum effort within 3 different conditions. Post warm-up was always with a standard bat (I = .27 kgm2; 83.8 cm, 9.1 N). Warm-up for Condition 1 was with the standard bat. Condition 2 required participants to warm up with a standard bat plus a 6.1 N lead donut (I = .49 kgm2, 83.8 cm, 15.6 N). Condition 3 required participants to warm up with a hollow plastic bat (I = .08 kgm2; 83.8 cm, 3.34 N). Quantitative and qualitative analyses indicated that following warm-up with the weighted bat (largest moment of inertia), swing pattern was significantly altered, and post warm-up velocity was the lowest of the three conditions. 相似文献