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Experimental and theoretical research in archery 总被引：1，自引：0，他引：1
R Pekalski 《Journal of sports sciences》1990,8(3):259-279
The aim of this study was to introduce certain methods and research techniques and to present the results of experiments on parameters of archery equipment to optimize the interaction of the archer-bow-arrow system's elements. In order to achieve the research requirements, the following were devised: 1. A mathematical model of an arrow's movement during its interaction with a bow. 2. A mechanical model of an archer-bow-arrow system, which constitutes a device for mechanical loosing of an arrow from the bow strings (DMLA). 3. Three series of high-speed filming. The mathematical model and computer simulation were used to describe the arrow's movement for various initial conditions and various parameters of the equipment, based on which a nomogram was constructed of the optimum arrow parameters for bows of various draw forces. The device for the mechanical loosing of arrows from a bow was used to study the influence of selected parameters of the archer-bow-arrow system on the accuracy of shots. The film analysis was used to verify the mathematical and mechanical models constructed. 相似文献
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本文以新疆锡伯族传统弓箭文化的产业化为主要对象,通过阅读相关的书籍资料,得出锡伯族弓箭文化的发展历史及濒危现状,调查研究理清发展脉络,对存在的问题进行分析,并提出非物质文化遗产项目的顺利运作和政府推动民间组织的"三角模式"互动机制是弓箭文化产业化的重要发展对策。研究结果显示,弓箭文化产业化公司的成立在市场中占据很大的优势地位,建立弓箭文化产业化公司同时也在传承和保护锡伯族濒危的弓箭文化,对于国家级非物质遗产保护项目也有着重要的作用。 相似文献
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A predominant archery coaching tenet holds that the most effective means of releasing the bow string is by relaxation of the finger flexor muscles without activation of finger extensors. To evaluate the validity of this view, EMG patterns of the flexor digitorum superficialis and extensor digitorum muscles of the draw arm were examined using surface EMG electrodes in 15 highly skilled archers as each performed six shots. Each archer displayed consistent EMG patterns from shot-to-shot and two distinct flexor-extensor patterns were exhibited by the sample. The first, characterized by eight of the archers, supported the relaxation principle. For these archers, both flexor and extensor digitorum activity decreased markedly immediately prior to or at arrow release. The second pattern, characteristic of the remaining seven archers, contradicted the coaching tenet. While the flexor digitorum pattern was essentially the same as that described for the first pattern, the extensor digitorum displayed a marked increase in activity just prior to release, indicating that string release was facilitated by an active extension of the fingers. It was concluded that highly skilled archers do not predominantly reflect a release consistent with the coaching canon and that factors other than the string release mechanism discriminate the performances of skilled archers. 相似文献
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《European Journal of Sport Science》2013,13(4):213-222
Abstract At the end of the aiming phase, an archer pulls the arrow back a little bit before he releases the shot. This pulling back of the arrow is called the “final pull”. Simultaneous with the final pull, the archer has to hold the bow calm. The aim of this paper was to examine the motion of the bow and the final pull in highly skilled archers. From a technological point of view, we wished to develop a system to measure the draw-length in the final pull that could be used during archers’ normal training. Seven archers (two males, five females), all of whom were participants at the Junior World Championships and German National Championships, performed 66 shots indoors at a target 30 m away. Each archer shot the same bow as used in competition. On-target trajectories of the aim point movement were measured. Also, the alterations of the draw-length in the final pull were determined. The results suggest that irregularities in the final pull have a negative influence on archers’ scores. Intra-individually, a smaller range of motion of the bow in the last second before the shot appears to have a positive influence on archers’ scores. 相似文献
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Fine body movements and the cardiac cycle in archery 总被引：3，自引：1，他引：2
This study examined the relationships between postural sway, aiming time, the cardiac cycle time and the placement of the first finger movement within the electrocardiac cycle, with the quality of the arrow shot. A small group of elite male and female archers who shot either the recurve or the compound bow, freestyle or bare bow was used in this study. A total of 240 arrows were shot, classified as being of good, average or bad quality and analysed in detail. The analyses were undertaken over two occasions up to 100 days apart. The area of postural sway, as measured by the movement of the centre of pressure coordinates, varied significantly (P less than 0.05-0.001) both within and between trials for all archers and for all quality of arrows shot. There was a tendency for the area of postural sway to increase as the quality of the arrow shot decreased. This increase in postural sway exceeded, for arrows of bad quality, that exhibited as normal postural sway when standing relaxed and addressing the target with the hands at the side. Aiming time was variable within the quality of arrow shot, although it was consistent for each archer. In some cases the aiming time increased as the quality of the arrow decreased, whereas in the case of bare bow archery the aiming time tended to decrease as the quality of the arrow deteriorated. The cardiac cycle time increased significantly (P less than 0.05-0.01) as the archers approached the loose of the good quality arrows but there was no significant increase in cardiac cycle time when arrows of average or bad quality were shot. The most consistent parameter related to the quality of the shot was the placement of the first finger movement within the ST phase or the mid-cycle phase of the electrocardiogram for arrows of good quality (P less than 0.0001). 相似文献
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Masahide Murakami Masato Iwase Kazuya Seo Yuji Ohgi Reno Koyanagi 《Sports Engineering》2014,17(4):217-225
Ski jumping flight posture was analyzed for achieving large flight distance on the basis of high-speed video images of the initial 40 m part of 120-m ski jumping flight. The time variations of the forward leaning angle and the ski angle of attack were measured from the video images, and the aerodynamic forces were calculated from the kinematic data derived from the images. Some correlations were investigated between the initial-speed corrected flight distance and such parameters as the angles of jumper, the initial transition time and the aerodynamic force coefficients. The result indicated that small body angle of attack was a key for large flight distance in the initial phase of flight because of small drag force, and that the most distinctive fault of beginners was too large body angle of attack and ski angle of attack leading to aerodynamic stall. Too small drag force does not give an optimal condition for large flight distance because the lift force is also too small. The ratio of the lift to the drag was larger than 0.95 for advanced jumpers. 相似文献
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Postural consistency in skilled archers 总被引：2，自引：0，他引：2
The consistency of an archer's postural set at the moment of loose (arrow release) is commonly perceived to be an important determinant of success. The coach seeks, among other things, to provide the archer with information about postural consistency, details of which he acquires by eye or occasionally by video-recordings. The gains that might be achieved from more precise information are examined here. Nine skilled archers, classified into either skilled or elite groups according to their officially computed handicap, were continuously monitored and measured with a three-dimensional co-ordinate analyser (Charnwood Dynamics Coda-3 Scanner) while shooting two ends (series) of three arrows each. Considerable variability was observed in the precision with which the positions of head, elbow and bow at the moment of loose were replicated by archers of similar levels of skill. These results are interpreted to suggest that precise postural consistency may not be the primary feature distinguishing between the performance of archers at the higher skill levels. 相似文献
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To determine the flight of a ski jumper it is essential to know what aerodynamic forces are acting on the ski jumper. However,
few data on this are available, especially for a V-style ski jumping flight. We have measured the aerodynamic forces during
the free flight phase for a V-style, as well as a parallel-style, ski jump by employing a full-size model in a wind tunnel.
The aerodynamic force data, (drag, lift and pitching moment) were obtained to create an aerodynamic database. These forces
are given in polynomial form as functions of the angle of attack, the body-ski (forward leaning) angle and the ski-opening
(V-style) angle. Using the polynomial form database is a convenient way of obtaining the aerodynamic forces. Moreover, the
wind tunnel was equipped with a ground effect plate to measure the aerodynamic forces during the landing phase. It was found
that the difference between the lift with and without the ground effect plate increases with the ski-opening angle. The longitudinal
stability in the pitching motion of a body-ski combination is also discussed on the basis of the pitching moment data. This
indicates that a stable pitching oscillation of the body-ski combination may arise around an equilibrium point in the angle
of attack, the trim angle of attack, during flight. 相似文献
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采用文献资料、教学实验、数理统计等方法,对跳远起跳技术教学方法进行研究,提出了运用目标"俯角板起跳"练习的教学新方法.结果表明:运用目标"俯角板"起跳练习,能有效改进学生在跳远时的起跳技术及提高学生的起跳能力,在跳远教学中具有实际的可行性与推广性. 相似文献
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Recurve archery is an Olympic sport that requires extreme precision, upper body strength and endurance. The purpose of this research was to quantify how postural stability variables both pre- and post-arrow release, draw force, flight time, arrow length and clicker reaction time, collectively, impacted on the performance or scoring outcomes in elite recurve archery athletes. Thirty-nine elite-level recurve archers (23 male and 16 female; mean age?=?24.7?±?7.3 years) from four different countries volunteered to participate in this study prior to competing at a World Cup event. An AMTI force platform (1000Hz) was used to obtain centre of pressure (COP) measurements 1s prior to arrow release and 0.5s post-arrow release. High-speed footage (200Hz) allowed for calculation of arrow flight time and score. Results identified clicker reaction time, draw force and maximum sway speed as the variables that best predicted shot performance. Specifically, reduced clicker reaction time, greater bow draw force and reduced postural sway speed post-arrow release were predictors of higher scoring shots. It is suggested that future research should focus on investigating shoulder muscle tremors at full draw in relation to clicker reaction time, and the effect of upper body strength interventions (specifically targeting the musculature around the shoulder girdle) on performance in recurve archers. 相似文献
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研究目的:定量研究特定运动员某阶段射箭训练中各影响因素对中靶情况的作用,为改进训练提供依据。方法:用自行设计的射箭运动训练多参数实时同步检测系统对训练中的瞬时心率曲线、弓片应变、撒放时间、动作视频、靶视频、箭初速等参数进行实时同步检测,在非线性时变目标向量函数模型的一阶简化基础上,估算各影响因素的扰动量。结论:对两名运动员实测分析表明,撒放时间、心率等因素对不同运动员中靶的影响不同,为运动员个性化训练提供了参考方向。 相似文献
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Yong Ma Youhong Tang Nathan West Zhiyong Zhang Shijie Lin Qinzhen Zheng 《Sports Engineering》2016,19(2):81-90
In sailing regattas, the actions of sailboats are to meet, overlap, pursue, pass, anti-collide, and defend. The aerodynamic performance of a sail based on a numerical simulation method is reported in this study. The parameters affecting the sail’s aerodynamic force coefficients, namely sailing angle, attack angle, mast shape, pitch angle, and camber ratio, are analyzed. From the results, basic principles and corresponding tactics of sail trimming are discussed and recommended for the start, during the windward, running, and leeward legs, before the finish, and near the marks. Sailors in the regatta should decrease the interaction of air flows around the sail to increase the lift force. The sailing angle, attack angle, pitch angle, and camber ratio should be adjusted to the appropriate degree to speed the boat when it is balanced. Sail trimming tactics have been practiced by professional sailors in regattas during which they can be scientifically supervised to compete against each other at Olympic Games. 相似文献
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Marko Tiermas 《Sports Engineering》2017,20(2):155-162
An extended offset-eccentric model of an archery twin-round-wheel compound bow is derived. Varying some parameters of the model, the respective effects on the calculated force–draw curve are considered. Two static quality coefficients for the compound bow are introduced. It was found that the twin-round-wheel compound bow can be designed to be more energetic with the help of the model. For a bow with some modifications 18.5% increment of energy was calculated. Also a theoretical limit for the force–draw curve of the compound bow is concluded. 相似文献
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Alexander Nicolaides Nathan Elliott John Kelley Mauro Pinaffo Tom Allen 《Sports Engineering》2013,16(3):181-188
Topspin has become a vital component of modern day tennis. Ball-to-string bed and inter-string friction coefficients can affect topspin generation from a racket. The aim of this research was to determine the effect of string bed pattern on topspin generation. Tennis balls were projected onto nine head-clamped rackets with different string bed patterns. The balls were fired at 24 m/s, at an angle of 26° to the string bed normal with a backspin rate of 218 rad/s and outbound velocity, spin and angle were measured. Outbound velocity was shown to be independent of string bed pattern. Outbound angle increased with the number of cross strings, while outbound topspin decreased. In the most extreme case, decreasing the number of cross strings from 19 to 13 increased rebound topspin from 117 to 170 rad/s. 相似文献
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This paper describes the use of Pareto-optimal solutions for the screw kick in rugby. We attempted to optimise the initial
conditions for a screw kick. The optimisation was carried out using an elitist non-dominated sorting genetic algorithm. Distance
achieved in flight is considered as an objective function, as well as the lateral deviation between the ball and the touchline,
or the flight time. Six initial conditions were defined as control parameters: the magnitude of the velocity vector, the flight
path angle, the azimuth angle, the spin rate, the pitch angle and the yaw angle. The results are summarised as follows: it
is impossible for both objective functions to be satisfied simultaneously, although the greatest distance achieved in flight
and the smallest value of the lateral deviation between the ball and the touchline, or the least flight time, is the ideal
situation. This kind of conflicting solution is called a ‘Pareto-optimal solution’. The optimal kick in Pareto-optimal solutions
made by the leg nearest the touchline produces a greater flight distance than the optimal kick in Pareto-optimal solutions
made using the leg furthest from the touchline. The initial pitch angle, which is the angle between the longitudinal axis
of the ball and the horizontal plane, should be comparable to or slightly greater than the initial flight path angle in order
to satisfy the Pareto-optimal solutions. 相似文献
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冉孟刚 《体育科技文献通报》2011,19(5):108-111
＂傩舞＂是我们的祖先创造出来的艺术形式之一。是古代百姓用以＂驱逐四方疫鬼＂的一种仪式。在长期的发展过程中,傩舞增加了许多娱乐的成分,其舞步许多都能与现代舞曲的节奏合拍。研究发现,如独舞《开天辟地》,可以用迪斯科伴奏到底;《后羿射日》是双人舞,可以用伦巴和探戈音乐伴奏始终;又如《八仙上寿》,则是迪斯科、伦巴、慢四、探戈、华尔兹舞等舞步之大成,头、手、足、臀、腰配合默契,随着＂嘭嚓嚓＂的不断变化,时而狂热、时而深情、时而奔放地展现在观众面前。所不同的是配舞的音乐,现代舞是＂嘭嚓嚓＂,傩舞用是＂咚咚锵＂,然而节拍基本上是一致的。从一定意义上可以说傩舞有着重要的健身价值。＂傩舞＂能使家庭和睦、邻居团结,对建设和谐社会有积极的推动作用。 相似文献
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标枪飞行轨迹的计算机仿真及实际应用 总被引：8，自引：0，他引：8
研究采用风洞实验和计算机仿真的方法，计算标枪在三维空间的飞行轨迹，对影响标枪飞行远度的各种因素，如出手速度、出手角度、初始攻角、初始俯仰角速度、初始偏航角等进行了定量分析，本文还根据标枪运动员投掷的实际情况提出了女子标枪运动员的最佳初始条件组合。 相似文献
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In this paper, the scientific literature and that on the sports sciences relevant to javelin throwing is critically reviewed. This is particularly timely because of the change in the specification of the javelin for the men's event, which was introduced by the IAAF in 1986. A full discussion of the aerodynamics of the javelin is presented with due consideration of the change in pitching moment characteristics that the rules change had brought about. The uses and limitations of current computer programs for simulating javelin flight, in order to estimate optimal release parameters, are profiled. Consideration is also given to the effects of wind velocity, air density, javelin weight and the flutter and spin of the javelin on its flight. The review further considers the optimization of release parameters, drawing upon computer simulations and field-based data. The effects of release speed, release height, release angle, release angle of attack and release pitch rate are assessed. The javelin throwing technique is discussed in relation to cinematographically derived data, including an evaluation of experimental procedures. The importance to successful performance of the grip, the run-up and transition phases, the cross over and delivery strides are each reviewed. Finally, some prognoses as to the direction of future research into this complex throwing skill are offered. 相似文献