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1.
Hemispheric asymmetry, cardiac response, and performance in elite archers   总被引:4,自引:0,他引:4  
Previous sport research on elite athletes has shown systematic changes in psychophysiological measures, such as heart rate (HR) deceleration and hemispheric asymmetries in EEG activity, in the few seconds prior to executing a motor response. These changes are believed to be due to a more focused attention on the external environment. Using archery (an attentive state), this investigation was designed to examine: (a) whether hemispheric asymmetry and HR deceleration would occur during the aiming period, and (b) if they did, whether this would affect performance. HR and left and right temporal EEG were recorded from 28 right-handed elite archers for 16 shots. The results indicated that (a) there was no HR deceleration; (b) during the aiming period, EEG alpha activity formed the dominant frequency and this was significantly greater in the left than in the right hemisphere; (c) there were no significant right hemisphere EEG changes in spectral power from 3 s before the shot to arrow release, but there were significant left hemisphere increases at 10, 12, and 24 Hz; and (d) at 1 s prior to the shot, there were no significant right hemisphere spectral power differences between best and worst shots, but there were significant left hemisphere differences at 6, 12, and 28 Hz. The relationships among hemispheric asymmetry, HR deceleration, attentional processes, and shooting performance are discussed.  相似文献   

2.
通过脑电相干性分析,探讨运动员射击中击发和收枪两种不同运动表现时各脑区间的沟通差异。采用64导脑电测试系统记录12名女子气手枪运动员击发与收枪时的脑电,将两种不同表现击发前的脑电分为4个时间段(每段1 000 ms),分别计算低-alpha频段(8~10 Hz)、高-alpha频段(11~13 Hz)、低-beta频段(14~22 Hz )中前额区(Fz)与其他脑区间(额区、中央区、顶区、枕区和颞区)的相干性。结果发现,在低-alpha频段,与收枪时相比,运动员击发时大脑信息沟通较少,表明击发时运动员只需要较低的皮层唤醒和注意努力。左脑脑波相干性显著低于右脑,表明大脑半球不同功能体现在了运动员射击过程中,运动员射击时右半球交流多,注意力转移以视觉空间为主。不同表现过程中不同时间点显示了不同高低的脑波相干性,故推断稳定的大脑皮质活动与较好的运动表现有关。  相似文献   

3.
Abstract

The effects of stance angle on postural stability and shooting processes were studied using eight national-standard male air-pistol shooters. Each shooter performed 60 shots each in four stance angles (0°, 15°, 30° and 45° from the line of fire). Postural stability was determined by measuring change in centre of pressure with a dual-force platform system assessing centre-of-pressure (COP) excursion (average difference of the centre of pressure from the mean) and COP speed (total COP path divided by time). Shooting process measures were determined by using a NOPTEL ST-2000 optoelectronic system. Score was assessed with a Sius Ascor S10 electronic scoring system. The results revealed no significant difference among the various stance angles; COP excursion or COP speed, p>0.05. Results indicated a significant stance angle effect with the shooting process measure, hit fine (percentage of hold within an area the size of the 10-ring when centred over the actual shot; p = 0.025) and the shooting performance measure adjusted score (raw score adjusted for true zero; p=0.008). Moreover, best overall performance was with a stance angle of 15°. These findings suggest that stance angle may affect pistol stability and performance in air-pistol athletes.  相似文献   

4.
This study examined the influence of physical exercise on the relation between shooting accuracy and the phase of the cardiac cycle in which the shot is fired. Thirteen experienced biathletes (8 females, mean age 17 years) fired from the standing position at rest and right after a submaximal exercise on a bicycle ergometer. Shooting accuracy and the timing of each shot relative to the R-waves of the electrocardiogram (ECG) were recorded. Best shots (with greatest accuracy) and worst shots (with lowest accuracy) were fired prevalently in different phases of the cardiac cycle. In the rest condition, best shots were fired less frequently from 200 to 300?ms and more frequently from 500 to 600?ms after the R-wave, compared to worst shots. In the exercise condition, best shots were fired less frequently from 100 to 200?ms after the R-wave and from 20% to 30% of the R-R interval, compared to worst shots. These findings support the hypothesis that shooting accuracy is influenced by the cardiac cycle phase due to the ballistocardiac recoil generated at each heartbeat. To achieve best results athletes could be trained (e.g. through biofeedback) to fire within a specific phase of the cardiac cycle.  相似文献   

5.
The aim of the present study was to determine whether changing stance width would result in a corresponding change in postural and/or pistol stability. Twelve national-standard male air pistol shooters performed 10 shots each at five stance widths (30 cm, 45 cm, 60 cm, 75 cm, and 90 cm). Postural stability was determined by measuring centre-of-pressure changes with a dual force-platform system. Shooting mechanics measures were determined by a NOPTEL ST-2000 optoelectronic training system. Medial-lateral centre-of-pressure excursion (F?,?? = 7.17, P < 0.001, effect size = 0.99) and speed (F?,?? = 77.03, P < 0.001, effect size = 3.88) were reduced as stance width decreased. Centre of gravity fine (the percentage of time held within an area the size of the ten-ring) improved during narrower stance widths (F?,?? = 12.49, P < 0.001, effect size = 0.71). Our findings suggest that stance width affects postural and pistol stability in national-standard air pistol athletes. Moreover, the current method of suggesting a wider stance to improve shooting performance should be reconsidered and perhaps air-pistol shooters should use a 30-cm stance width to improve postural stability and shooting performance.  相似文献   

6.
The purpose of this study was to examine the variability in cortical activation during physical air-rifle shooting and three different observation conditions. Elite air-rifle shooters performed a 40 shot individual match. Electroencephalograms were recorded from 11 active sites across the cortex during the final 6 s (3 x 2 s epochs) before shot release. Data collection was repeated while shooters watched a large-screen video of their worst shot performance from an internal-visual perspective when seated, standing and standing holding their rifle. The hypothesized differences between the three observation conditions and the physical shooting profile were not shown except at the left anterior temporal site, T5. This finding suggests that observation of performance cannot be differentiated clearly by posture or modified through kinetic and haptic afference, and that visual percepts predominate in observational functional equivalence. However, more functionally equivalent observation reduced the observation/execution variability over the temporal areas. Performer debriefs also identified different perceptions of physiological, psychological and behavioural functional equivalence associated with the different observation conditions. We conclude that elite performers' brains are accessed equally effectively during different observation conditions irrespective of some of the physical factors ascribed to the conditions. However, they may require more functionally matched conditions to attain greater equivalence in temporal areas.  相似文献   

7.
The purpose of this study was to investigate the temporal phases of the archery shot cycle that distinguish the arrows distance from centre, in an attempt to understand critical factors that affect performance. Fifteen archers of varying ability each performed 30 shots at 18 m. Fourteen potential predictor variables were measured for statistical modelling by stepwise multiple linear regression. The results show that pre-shot time (pre-performance routine), follow-through time (post-performance routine), aiming time, speed of the arrow and the %variation in clicker-release time, account for 7.7% of the variation in predicting shot performance. The results have implications for practice demonstrating factors that coaches should focus on to develop their athletes. Further work on pre-, but more importantly, post-performance routines are needed generally within sport research as they are lacking and have been shown to be important contributing factors in a number of sports.  相似文献   

8.
The ability to shoot an effective jump shot in the sport of basketball is critical to a player's success. In an attempt to better understand the aspects related to expert performance, researchers have investigated successful free throws and jump shots of various basketball players and identified movement variables that contribute to their success. The purpose of this study was to complete a systematic review of the scientific literature on the basketball free throw and jump shot for the purpose of revealing the critical components of shooting that coaches, teachers, and players should focus on when teaching, learning, practising, and performing a jump shot. The results of this review are presented in three sections: (a) variables that affect ball trajectory, (b) phases of the jump shot, and (c) additional variables that influence shooting.  相似文献   

9.
Abstract

The purpose of this study was to examine the variability in cortical activation during physical air-rifle shooting and three different observation conditions. Elite air-rifle shooters performed a 40 shot individual match. Electroencephalograms were recorded from 11 active sites across the cortex during the final 6 s (3 × 2 s epochs) before shot release. Data collection was repeated while shooters watched a large-screen video of their worst shot performance from an internal-visual perspective when seated, standing and standing holding their rifle. The hypothesized differences between the three observation conditions and the physical shooting profile were not shown except at the left anterior temporal site, T5. This finding suggests that observation of performance cannot be differentiated clearly by posture or modified through kinetic and haptic afference, and that visual percepts predominate in observational functional equivalence. However, more functionally equivalent observation reduced the observation/execution variability over the temporal areas. Performer debriefs also identified different perceptions of physiological, psychological and behavioural functional equivalence associated with the different observation conditions. We conclude that elite performers' brains are accessed equally effectively during different observation conditions irrespective of some of the physical factors ascribed to the conditions. However, they may require more functionally matched conditions to attain greater equivalence in temporal areas.  相似文献   

10.
Abstract

The aim of the present study was to determine whether changing stance width would result in a corresponding change in postural and/or pistol stability. Twelve national-standard male air pistol shooters performed 10 shots each at five stance widths (30 cm, 45 cm, 60 cm, 75 cm, and 90 cm). Postural stability was determined by measuring centre-of-pressure changes with a dual force-platform system. Shooting mechanics measures were determined by a NOPTEL ST-2000 optoelectronic training system. Medial-lateral centre-of-pressure excursion (F 4,44 = 7.17, P < 0.001, effect size = 0.99) and speed (F 4,44 = 77.03, P < 0.001, effect size = 3.88) were reduced as stance width decreased. Centre of gravity fine (the percentage of time held within an area the size of the ten-ring) improved during narrower stance widths (F 4,32 = 12.49, P < 0.001, effect size = 0.71). Our findings suggest that stance width affects postural and pistol stability in national-standard air pistol athletes. Moreover, the current method of suggesting a wider stance to improve shooting performance should be reconsidered and perhaps air-pistol shooters should use a 30-cm stance width to improve postural stability and shooting performance.  相似文献   

11.
结合教学训练的实践,就应急射击中快打的姿势和动作特点,右手握枪的位置及力量,枪支指向,预压与击发,注意转靶练习,集中注意力与抓住重点环节,关于第二发射击的问题等进行了分析。  相似文献   

12.
通过文献资料法、录像观察法、专家访谈法、问卷调查法、数理统计法等研究方法对第16届男篮世锦赛中国队与对手及前4强球队前锋队员个人投篮得分能力指标进行了统计与比较分析,研究结果表明:中国男篮前锋队员平均年龄相对较小,运动技能、心理状态、临场比赛意识、经验等都还没达到鼎盛的阶段;身高已达到或者接近世界优秀运动员的水平;体重方面明显低于国外其他球队。中国队得分能力远不如世界强队,总的投篮次数少。中国男篮前锋队员在近区、中区的投篮得分方面与国外前锋相比已经有一定的提高,远区投篮次数明显低于国外前锋队员,与前4强相比更是存在很大的差距。中国男篮前锋队员在比赛中投篮受到较大的干扰,受干扰下的投篮命中率低。投篮方式过于单一,以原地跳投、贴身投篮、突破投篮为主,其中原地跳投最多;对手也是原地跳投为主,其次是突破投篮和贴身投篮,投篮方式运用的顺序上与世界强队存在一定差别。  相似文献   

13.
A rationale and geometric parameters for optimal basketball shooting are provided. The premise is that shots requiring the least energy are the easiest to control and thus have the greatest probability of success. The kinematics of the ball movement are modelled and simulated for the free throw, for the direct shot, and for the bank shot off the backboard (the ‘layup’). For the layup, the analysis includes the effects of friction, ball inertia, ball spin and impact restitution. The results provide a means for shot planning and for coaching to improve shooting technique. The advantage of the layup for close-in shooting is demonstrated. Results of numerical parameter studies are also presented, demonstrating the ranges of allowable shooting error for the various shots, and thus also identifying the shots with highest probability of success.  相似文献   

14.
安燕  郑樊慧 《浙江体育科学》2012,34(3):90-93,97
运动表象是运动员在训练和比赛中广泛使用的一种非常有效的心理训练方法,也是研究者十分关注的重要研究主题。研究采用EEG来对运动表象进行测量,从心理生理学的角度探索专家与新手之间的差别,研究得出:专家与新手之间安静状态下大脑的神经活跃程度相似,并未因训练不同而产生差异。在运动表象过程中大脑左右半球并没有出现大脑侧性优势。运动表象时专家与新手的差异性出现与运动相关的区域,δ波在左额极区(FP1)、左中央区(C3)、左顶区(P3);α波在左中央区(C3)和左顶区(P3)、右顶区(P4)和左枕区(O1);β波在右顶区(P4)存在显著性差异,其皮层激活在左侧区域分布广泛。运动表象过程中α波增加而不是受到抑制,在视觉表象中出现α波抑制。  相似文献   

15.
The effectiveness of pre-performance routines on skilled performance in a self-paced skill has yet to be verified. In this study, we examine the importance of temporal and behavioural consistency in these routines. The duration and specific pattern of behaviours exhibited before each free throw (n = 284) were observed during 14 National Basketball Association play-off games. An intra-individual standardized score was calculated for each shot's duration. Each player's dominant behavioural routine was identified and each shot was classified as "sequence followed" or "sequence not followed". No difference was observed in the success rates of shots associated with brief, long, and regular duration routines (P > 0.05). However, players were more successful when they followed their dominant behavioural sequence (83.77% success) than when they deviated from their specific behavioural pattern (71.43% success) (P < 0.05). The findings are interpreted in light of relevant theory and implications for practice are discussed.  相似文献   

16.
牛晓雷 《浙江体育科学》2005,27(2):45-47,79
运用文献资料法、观察法、数理统计法等研究方法,以2004年欧洲足球锦标赛的31场比赛为研究对象,对所有比赛中运用远射的情况进行统计.通过对远射的数量、效果、时机、脚法和区域进行分析,结果发现:远射在比赛中运用有一定的规律性,是射门中一项关键技术,也是破门得分的良好手段之一.中路3区是远射得分的最佳区域,尤其是罚球弧附近.远射的脚法一般以脚背正面或脚背内侧为主.远射的时机决定射门效果.  相似文献   

17.
Abstract

A postural tremor appears whenever someone attempts to maintain a steady position against gravity. We examined the postural tremor that occurred while air pistol shooters were taking aim so as to compare the coordinative control of the shooters and to identify the features critical to successful shooting. Ten elite and ten pre-elite athletes participated in pistol shooting at 10 m, and the postural tremors in the pistol and upper limb were recorded with lightweight accelerometers. Exploratory analysis showed that the elite shooters had smaller tremor amplitudes than the pre-elite shooters in the pistol and distal arm segments. Compared with the pre-elite shooters, the elite shooters had a smaller tremor amplitude in the lateral direction relative to that in the vertical direction, together with weaker tremor coupling in the lateral direction and stronger vertical coupling of the pistol–hand complex. The resulting shot performance was inversely related to the amplitude of the tremor and to the 8–12 Hz spectral peak of the lateral tremor in the pistol–hand complex. We conclude that the postural tremors of air pistol shooters are associated with the skill of the shooters, and that the elite shooters could optimize the control of the pistol–hand complex, which strongly determined success in shooting.  相似文献   

18.
Postural tremor and control of the upper limb in air pistol shooters   总被引:2,自引:1,他引:1  
A postural tremor appears whenever someone attempts to maintain a steady position against gravity. We examined the postural tremor that occurred while air pistol shooters were taking aim so as to compare the coordinative control of the shooters and to identify the features critical to successful shooting. Ten elite and ten pre-elite athletes participated in pistol shooting at 10 m, and the postural tremors in the pistol and upper limb were recorded with lightweight accelerometers. Exploratory analysis showed that the elite shooters had smaller tremor amplitudes than the pre-elite shooters in the pistol and distal arm segments. Compared with the pre-elite shooters, the elite shooters had a smaller tremor amplitude in the lateral direction relative to that in the vertical direction, together with weaker tremor coupling in the lateral direction and stronger vertical coupling of the pistol-hand complex. The resulting shot performance was inversely related to the amplitude of the tremor and to the 8-12 Hz spectral peak of the lateral tremor in the pistol-hand complex. We conclude that the postural tremors of air pistol shooters are associated with the skill of the shooters, and that the elite shooters could optimize the control of the pistol-hand complex, which strongly determined success in shooting.  相似文献   

19.
通过对第5届女足世界杯32场比赛的962次射门统计,结果表明:本届世界杯射门次数增多,但是进球率显著下降;总射门的97.3%在E、B区完成,超过28的射门是由中前场发动进攻形成;定位球和抢断球发动进攻形成的射门最多;总射门的47.8%在完成前只有2次以下的传球,29.0%的射门形成时间在4s以下等等;形成射门的进攻战术模型有中后场发动逐步进攻射门模型,前场定位球进攻射门模型苘场发动阵地进攻射门模型,底传中、边路长传中进攻射门模型,中后场定位球、长传快攻进攻射门模型,边路射门、门前补射进攻射门模型。  相似文献   

20.
In golf, unlike most other sports, individual performance is not the result of direct interactions between players. Instead decision-making and performance is influenced by numerous constraining factors affecting each shot. This study looked at the performance of PGA TOUR golfers in 2011 in terms of stability and variability on a shot-by-shot basis. Stability and variability were assessed using Recurrence Quantification Analysis (RQA) and standard deviation, respectively. About 10% of all shots comprised short stable phases of performance (3.7 ± 1.1 shots per stable phase). Stable phases tended to consist of shots of typical performance, rather than poor or exceptional shots; this finding was consistent for all shot categories. Overall, stability measures were not correlated with tournament performance. Variability across all shots was not related to tournament performance; however, variability in tee shots and short approach shots was higher than for other shot categories. Furthermore, tee shot variability was related to tournament standing: decreased variability was associated with better tournament ranking. The findings in this study showed that PGA TOUR golf performance is chaotic. Further research on amateur golf performance is required to determine whether the structure of amateur golf performance is universal.  相似文献   

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