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1.
通过对我国优秀板球运动员快速投球中投掷步技术的运动学测量,并且与国外运动员在关键指标上进行比较发现:在我国运动员中存在着混合型快速投球方式,且我国运动员球出手速度较低,在投掷步开始时身体重心水平速度较低,在前脚着地至球出手期间前腿膝关节弯曲幅度较大,在球出手时前腿膝关节角较小,在投掷步中肘与腕关节的最大速度较低,投掷臂运动对球出手速度的贡献较低。因此,我国运动员成绩提高的有效途径:转变已有的混合型快速投球技术,根据自身特点选择其它合适的快速投球技术类型;注重助跑速度的适当地提高以及跳步与投掷步衔接技术的改善;在前脚着地时前腿膝关节屈曲至150°以上,然后维持这个角度直至球出手;适度地增加投掷步步长;加强投掷臂挥臂技术以及肩关节的力量训练。 相似文献
2.
为进一步明确影响棒球投手投球速度的关键因素,通过中国知网、Web of Science和PubMed等平台以棒球投手、投球速度、运动生物力学和鞭打动作等为关键词,检索并整理归纳20世纪90年代至今的相关文献资料。通过对比国内外优秀棒球投手投球速度和专项技术能力,发现投球时投掷臂肩关节外旋角度、肩关节水平外展角度、肘关节角度、躯干前倾幅度、前腿膝关节角度等运动学指标,投掷臂各环节受力峰值、前腿受到的最大地面反作用力等动力学指标均对投球速度起关键性影响作用。教练员和棒球投手可通过改善上下肢关节角度和角速度等指标参数的大小、增强肌肉力量和柔韧性等手段,完善投手投球技术动作,提高投球速度。 相似文献
3.
棒球运动是以击球跑垒、跑垒得分的进攻行为与投球、接传球的防守行为相对抗为特点的运动项目.在棒球比赛中,投手的球投得好,就能控制击球员的击球,全面控制对方的进攻.因此投手投球的技术战术和心理战术起着十分关键的作用,决定了全局的比赛.通过结合近年来国内、外学者对棒球投手的运动生物力学研究成果,探讨投手投球技术战术及技术战术... 相似文献
4.
邵年 《沈阳体育学院学报》1987,(3)
后摆式投球是垒球投手三种投球姿势中的一种,是掌握8字绕环投球动作的基础。它的特点是:动作幅度大、节奏强、伸踏大、出手点低、出球动作呈直线形、易控制球、可投出上升的直线球,具有一定的攻击能力。后摆式投球方法在我国曾被广泛采用,使用这种投法也曾出现过具有“快速投手”美称的李念敏和天津队的许桂香等垒球名手。她们把独特的风格、娴熟的技巧和丰富的垒球临场比赛经验融为一体,在多次重大国内外比赛中有良好的表现。但是近几年来, 相似文献
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浅析垒球项目中优秀投手的技术动作 总被引：1，自引：0，他引：1
文章探讨了垒球比赛中投手在防守体系中的重要作用.通过对美、日传统强队投手的投球技术动作进行分析,着重分析了投球腿部伸踏技术动作与上肢屈臂技术动作,为不断改进和提高我国投手的技术动作提供参考依据. 相似文献
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要学习棒球投手投球技术,首先要懂得球的握法。不同的握法产生不同性能的球。一个有训练的棒球投手,可以投出直线快球,各种变速球,还可以投出不同性质的曲线球。如常见的内曲线球、外曲线球,内外曲线下坠球,下坠球,上飘球,不旋转球等。一、球的握法: (一)直线球的握法:利用食指,中指和指拇的握法。食指和中指的指尖要压在线缝上,拇指在下面对准食指和中指的中间。握球时,手腕要放松,否则会影响手腕力量的发挥图1。 相似文献
9.
1、投球技术分析
投手的投球姿势可以分为高手、侧手及介于两个手位问的四分之三投球。每一种投球的方式都有其优缺点，如果了解其中优点和特点之后，就可以选择一种最适合自己的方式投球，对于训练两三年的业余青少年队员最好采用高压式和四分之三式投球。无论是正面投球和侧面投球技术，其动作结构都由一气呵成的连贯动作组成。 相似文献
10.
篮球比赛以得分多的一方获胜。投篮成功才能得分。成功决定因素主要是投篮技术正确与否。应用抛体运动物理解释;与投球的高度、出手的角度、出球的速率密切相关。另外同球的旋转关系极大。 投篮精确性随着投篮距离变化。不同距离同样高度和同样距离不同高度的投球都具有不同的投球角度,不同的用力和不同的出手速率。任何投球动作,入篮角度大,出手角度和出手速率也越大。 相似文献
11.
In order to get bounce and movement seam bowlers need to bowl the ball “into” the pitch. Standard deliveries by elite players are typically projected at around 7° below horizontal. In contrast, young players currently often need to release the ball almost horizontally in an effort to get the ball to bounce close enough to the batter. We anticipated that shortening the pitch could be a simple way to help young bowlers to release the ball at a better angle and with more consistency. Twenty county or best in club age group under 10 and under 11 seam bowlers were analysed bowling indoors on two different pitch lengths. They were found to project the ball on average 3.4° further below horizontal on a 16 yard pitch compared with a 19 yard pitch, while ball speed and position at release changed negligibly. Pitch length did not affect the consistency of the release parameters. The shorter pitch led to a ball release angle closer to that of elite bowlers without changing release speed, and this should enable players to achieve greater success and develop more variety in their bowling. 相似文献
12.
ABSTRACT When executed correctly, swing bowling has the potential to influence the outcome of a cricket match, yet little is known about the required bowling action and ball flight characteristics. This study aimed to describe the bowling action and initial ball flight characteristics as well as to identify variables that may be associated with increased swing in pathway and high-performance medium and fast pace bowlers. A 17-camera Vicon motion analysis system captured retro-reflective markers placed on the upper-body of participants and new cricket balls to quantify bowling action and initial ball flight kinematics. Bowlers delivered the ball with their forearm and hand angled in the direction of intended swing with an extended wrist flexing through the point of ball release. Bowlers who produced more swing had increased seam stability, possibly linked to a lower wrist and ball angular velocity. It is believed that swing increases with seam stability, however, optimal ranges may exist for seam azimuth angle, ball angular velocity and release speed. These findings may assist coaches to optimise the performance of bowlers, however, future research should use bowlers who play at higher levels to investigate swing bowling at greater speeds. 相似文献
13.
René E.D. Ferdinands Uwe G. Kersting 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(3):315-333
Cricket bowling is traditionally thought to be a rigid-arm motion, allowing no elbow straightening during the delivery phase. Conversely, research has shown that a perfectly rigid arm through delivery is practically unattainable, which has led to rule changes over the past years. The current rule requires a bowler not to increase the elbow angle by more than 15°, thus requiring a measurement to confirm legality in “suspect” bowlers. The aims of this study were to evaluate whether the current rule is maintained over a range of bowlers and bowling styles, and to ascertain whether other kinematics measures may better differentiate between legal and suspect bowling actions. Eighty-three bowlers of varying pace were analysed using reflective markers and a high-speed (240 Hz) eight-camera motion analysis system in a laboratory. The change in elbow segment angle (minimum angle between the arm and forearm), the change in elbow extension angle with respect to the flexion–extension axis of a joint coordinate system, and the elbow extension angular velocity at ball release were measured. We found that bowlers generally bowled within a change in elbow extension angle of 15°. However, this limit was unable to differentiate groups of bowlers from those who were suspected of throwing in the past. Improved differentiation was attained using the elbow extension angular velocity at ball release. The elbow extension angular velocity at ball release may be conceptually more valid than the elbow extension angle in determining which bowlers use the velocity-contributing mechanisms of a throw. Also, a high value of elbow extension angular velocity at ball release may be related to the visual impression of throwing. Therefore, it is recommended that researchers and cricket legislators examine the feasibility of specifying a limit to the elbow extension angular velocity at ball release to determine bowling legality. 相似文献
14.
Ferdinands RE Kersting UG 《Sports biomechanics / International Society of Biomechanics in Sports》2007,6(3):315-333
Cricket bowling is traditionally thought to be a rigid-arm motion, allowing no elbow straightening during the delivery phase. Conversely, research has shown that a perfectly rigid arm through delivery is practically unattainable, which has led to rule changes over the past years. The current rule requires a bowler not to increase the elbow angle by more than 15 degrees, thus requiring a measurement to confirm legality in "suspect" bowlers. The aims of this study were to evaluate whether the current rule is maintained over a range of bowlers and bowling styles, and to ascertain whether other kinematics measures may better differentiate between legal and suspect bowling actions. Eighty-three bowlers of varying pace were analysed using reflective markers and a high-speed (240 Hz) eight-camera motion analysis system in a laboratory. The change in elbow segment angle (minimum angle between the arm and forearm), the change in elbow extension angle with respect to the flexion-extension axis of a joint coordinate system, and the elbow extension angular velocity at ball release were measured. We found that bowlers generally bowled within a change in elbow extension angle of 15.5 degrees. However, this limit was unable to differentiate groups of bowlers from those who were suspected of throwing in the past. Improved differentiation was attained using the elbow extension angular velocity at ball release. The elbow extension angular velocity at ball release may be conceptually more valid than the elbow extension angle in determining which bowlers use the velocity-contributing mechanisms of a throw. Also, a high value of elbow extension angular velocity at ball release may be related to the visual impression of throwing. Therefore, it is recommended that researchers and cricket legislators examine the feasibility of specifying a limit to the elbow extension angular velocity at ball release to determine bowling legality. 相似文献
15.
Ferdinands R Marshall RN Kersting U 《Sports biomechanics / International Society of Biomechanics in Sports》2010,9(3):139-152
Kinematic studies have shown that fast bowlers have run-up velocities, based on centre of mass velocity calculations, which are comparable to elite javelin throwers. In this study, 34 fast bowlers (22.3 +/- 3.7 years) of premier grade level and above were tested using a three-dimensional (3-D) motion analysis system (240 Hz). Bowlers were divided into four speed groups: slow-medium, medium, medium-fast, and fast. The mean centre of mass velocity at back foot contact (run-up speed) was 5.3 +/- 0.6 m/s. Centre of mass velocity at back foot contact was significantly faster in the fastest two bowling groups compared to the slow-medium bowling group. In addition, stepwise multiple regression analysis showed that the centre of mass deceleration over the delivery stride phase was the strongest predictor of ball speed in the faster bowling groups. In conclusion, centre of mass kinematics are an important determinant of ball speed generation in fast bowlers. In particular, bowlers able to coordinate their bowling action with periods of centre of mass deceleration may be more likely to generate high ball speed. 相似文献
16.
Robert Marshall René Ferdinands 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(1):65-71
The laws of bowling in cricket state ‘a ball is fairly delivered in respect of the arm if, once the bowler's arm has reached the level of the shoulder in the delivery swing, the elbow joint is not straightened partially or completely from that point until the ball has left the hand’. Recently two prominent bowlers, under suspicion for transgressing this law, suggested that they are not ‘throwing’ but due to an elbow deformity are forced to bowl with a bent bowling arm. This study examined whether such bowlers can produce an additional contribution to wrist/ball release speed by internal rotation of the upper arm. The kinematics of a bowling arm were calculated using a simple two‐link model (upper arm and forearm). Using reported internal rotation speeds of the upper arm from baseball and waterpolo, and bowling arm kinematics from cricket, the change in wrist speed was calculated as a function of effective arm length, and wrist distance from the internal rotation axis. A significant increase in wrist speed was noted. This suggests that bowlers who can maintain a fixed elbow flexion during delivery can produce distinctly greater wrist/ball speeds by using upper arm internal rotation. 相似文献
17.
Rene Ferdinands Robert N. Marshall Uwe Kersting 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(3):139-152
Kinematic studies have shown that fast bowlers have run-up velocities, based on centre of mass velocity calculations, which are comparable to elite javelin throwers. In this study, 34 fast bowlers (22.3 ± 3.7 years) of premier grade level and above were tested using a three-dimensional (3-D) motion analysis system (240 Hz). Bowlers were divided into four speed groups: slow-medium, medium, medium-fast, and fast. The mean centre of mass velocity at back foot contact (run-up speed) was 5.3 ± 0.6 m/s. Centre of mass velocity at back foot contact was significantly faster in the fastest two bowling groups compared to the slow-medium bowling group. In addition, stepwise multiple regression analysis showed that the centre of mass deceleration over the delivery stride phase was the strongest predictor of ball speed in the faster bowling groups. In conclusion, centre of mass kinematics are an important determinant of ball speed generation in fast bowlers. In particular, bowlers able to coordinate their bowling action with periods of centre of mass deceleration may be more likely to generate high ball speed. 相似文献
18.
P. J. Felton S. L. Lister P. J. Worthington M. A. King 《Journal of sports sciences》2019,37(6):665-670
This study investigated ball release speed and performance kinematics between elite male and female cricket fast bowlers. Fifty-five kinematic parameters were collected for 20 male and 20 female elite fast bowlers. Group means were analysed statistically using an independent samples approach to identify differences. Significant differences were found between: ball release speed; run-up speed; the kinematics at back foot contact (BFC), front foot contact (FFC), and ball release (BR); and the timings between these key instants. These results indicate that the female bowlers generated less whole body linear momentum during the run-up than the males. The male bowlers also utilised a technique between BFC and FFC which more efficiently maintained linear momentum compared to the females. As a consequence of this difference in linear momentum at FFC, the females typically adopted a technique more akin to throwing where ball release speed was contributed to by both the whole body angular momentum and the large rotator muscles used to rotate the pelvis and torso segments about the longitudinal axis. This knowledge is likely to be useful in the coaching of female fast bowlers although future studies are required to understand the effects of anthropometric and strength constraints on fast bowling performance. 相似文献
19.
The aim of this study was to assess the effect of pitch length (20.12 m [full length], 18 m and 16 m) on the fast bowling performance and technique of junior cricketers. Performance measures included ball release speed and accuracy, while technique variables evaluated were those shown to be related to the aetiology of lower back injury. Thirty-seven fast bowlers from the under-11 (n=14), under-13 (n=11) and under-15 (n=12) age groups were filmed bowling five deliveries at each of the above pitch lengths. Two synchronized NAC video cameras operating at 200 Hz permitted three-dimensional reconstruction of the hip and shoulder alignments, while a standard digital video camera operating at 50 Hz (positioned perpendicular to the bowling action) was used to measure front knee angle and ball release speed. Accuracy scores were taken from a zoned target at the batsman's stumps. A two-way analysis of variance with repeated measures (with age and pitch length as the between- and within-participant variables, respectively) was used to compare each age group at the 0.05 significance level. Results showed that accuracy improved in all age groups at shorter pitch lengths, although ball velocity remained constant throughout all trials. Shoulder counter-rotation increased significantly for the under-13 bowlers when bowling on the full-length pitch in comparison with the two shorter lengths. Counter-rotation also increased on the full-length pitch in the under-11 age group, although this increase was not significant. The under-15 bowlers' techniques did not change as pitch length increased. As under-11 and under-13 bowlers adopted a "safer" bowling action with superior accuracy on the 18?m compared with the full length pitch, it was concluded that these age groups should bowl on an 18?m pitch to reduce the likelihood of lower back injuries and improve accuracy. 相似文献
20.
Marshall R Ferdinands R 《Sports biomechanics / International Society of Biomechanics in Sports》2003,2(1):65-71
The laws of bowling in cricket state 'a ball is fairly delivered in respect of the arm if, once the bowler's arm has reached the level of the shoulder in the delivery swing, the elbow joint is not straightened partially or completely from that point until the ball has left the hand'. Recently two prominent bowlers, under suspicion for transgressing this law, suggested that they are not 'throwing' but due to an elbow deformity are forced to bowl with a bent bowling arm. This study examined whether such bowlers can produce an additional contribution to wrist/ball release speed by internal rotation of the upper arm. The kinematics of a bowling arm were calculated using a simple two-link model (upper arm and forearm). Using reported internal rotation speeds of the upper arm from baseball and waterpolo, and bowling arm kinematics from cricket, the change in wrist speed was calculated as a function of effective arm length, and wrist distance from the internal rotation axis. A significant increase in wrist speed was noted. This suggests that bowlers who can maintain a fixed elbow flexion during delivery can produce distinctly greater wrist/ball speeds by using upper arm internal rotation. 相似文献