共查询到20条相似文献，搜索用时 15 毫秒
1.
Reinoud J. Bootsma Marc H. J. Houbiers H. T. A. Whiting Pieter C. W. van Wieringen 《Research quarterly for exercise and sport》2013,84(3):276-284
Abstract Two groups of 10 novice subjects each were trained to perform attacking forehand drives in table tennis and land the balls as fast and as accurately as possible onto a target on the opposite side of the net under two different training conditions. Under the static training condition, the balls were to be struck from a constant position, and under the dynamic training condition, balls approached the subjects in a normal way. Both groups were tested under dynamic conditions prior to and after four days of training, during which they received 1,600 practice trials. Both groups of subjects were shown to increase the number of balls that landed on the target, and learning was also evident from an increased consistency of the direction of travel of the bat at the moment of ball/bat contact. However, no increase in consistency was found for the location of the bat at the moment of ball/bat contact and for the movement times. Thus, learning can occur in the absence of externally generated time-to-contact information, but this is not due to the establishment of a consistent movement form. Learning appears to progress from control at the moment of ball/bat contact backward, toward the moment of initiation. 相似文献
2.
Tabuchi N Matsuo T Hashizume K 《Sports biomechanics / International Society of Biomechanics in Sports》2007,6(1):17-30
The aims of this study were to examine whether batters hit stationary balls at the time of peak speed of the bat head and whether the impact occurs at the lowest point of the bat trajectory. Eight university baseball players hit three balls, each hung with a string; each ball was made of a different material and was different in weight. Bat movement was captured by four 240-Hz infrared cameras and analysed three-dimensionally. Time for peak speed of the bat head varied according to the conditions. When stationary balls of standard weight were used, the bat head was at maximum speed at impact with the ball; then, it decelerated drastically owing to the impact. In contrast, maximum speed was obtained after impact when lightweight stationary balls were used. The time-speed profile of the bat head before impact in the lightweight ball condition was identical with that in the standard weight ball condition. Regardless of conditions, the timing of the lowest point of the bat head was nearly identical for each batter and most participants hit the stationary balls at about the lowest point of the bat trajectory. 相似文献
3.
NORIYUKI TABUCHI TOMOYUKI MATSUO KEN HASHIZUME 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(1):17-30
The aims of this study were to examine whether batters hit stationary balls at the time of peak speed of the bat head and whether the impact occurs at the lowest point of the bat trajectory. Eight university baseball players hit three balls, each hung with a string; each ball was made of a different material and was different in weight. Bat movement was captured by four 240-Hz infrared cameras and analysed three-dimensionally. Time for peak speed of the bat head varied according to the conditions. When stationary balls of standard weight were used, the bat head was at maximum speed at impact with the ball; then, it decelerated drastically owing to the impact. In contrast, maximum speed was obtained after impact when lightweight stationary balls were used. The time–speed profile of the bat head before impact in the lightweight ball condition was identical with that in the standard weight ball condition. Regardless of conditions, the timing of the lowest point of the bat head was nearly identical for each batter and most participants hit the stationary balls at about the lowest point of the bat trajectory 相似文献
4.
Wulf G McNevin NH Fuchs T Ritter F Toole T 《Research quarterly for exercise and sport》2000,71(3):229-239
Experiment 1 examined whether it is more advantageous to direct learners' attention to the external effects of their movements relative to other external cues. Two groups of participants hit tennis balls at a target, with one group focusing on the ball coming toward them (antecedent) and the other group focusing on the ball leaving the racket (effect). The effect group demonstrated more effective learning. Experiment 2 examined whether it is more beneficial if the movement effect is related to the movement technique, relative to other movement effects (e.g., outcome). Two groups of participants hit golf balls at a target. The attention of these groups was directed to the club or the ball trajectory, respectively. The club group showed more effective learning than the target group, suggesting that focusing on technique-related effects is more effective. 相似文献
5.
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
6.
Hiromu Katsumata Keita Himi Tenpei Ino Kyohei Ogawa Takehiro Matsumoto 《Journal of sports sciences》2017,35(24):2468-2480
Baseball batters must react to pitches delivered to different locations within the strike zone by modulating their movements. In tee-batting practice, such batters place a ball on a tee stand at a location, where they intend to hit the ball, assuming a particular pitch’s trajectory. In the present study, we analysed three-dimensional movements in tee-batting to identify characteristics of the batters’ intended impact locations across the strike zone, thereby investigating spatiotemporal features of movement modulation. More specifically, 10 experienced baseball batters performed tee-batting at their preferred impact locations at nine different heights and courses within the strike zone. The distribution of impact locations showed regularity, i.e., the location shifted forward for balls placed high and inside, while it shifted backward for balls placed low and outside. Furthermore, trunk and arm movements showed systematic modulation as the impact locations changed. The duration of bat movement was also location dependent, i.e., hitting the inside ball took more time than hitting the outside ball. Our results indicate that even though movements among body segments were properly coordinated to adjust the bat swing for different impact locations, fine timing adjustments were also required to hit the ball at those preferred impact locations and therefore properly react to differences in flight paths. 相似文献
7.
M. SHARHIDD TALIEP USHMA GALAL CHRISTOPHER L. VAUGHAN 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(3):345-360
The aim of this study was to compare selected kinematic variables of the front foot off-drive in skilled and less-skilled cricket batsmen. High-speed digital cameras were used to record the three-dimensional kinematics of 10 skilled and 10 less-skilled right-handed batsmen when playing a shadow front foot off-drive to realistic projected video footage. Skilled batsmen were more likely to identify the type of delivery bowled. Seventy percent of skilled batsmen had preparatory feet or foot movement before committing to play forward, while only 20% of the less-skilled batsmen utilized this trigger movement. Throughout the drive, the head of the skilled batsmen was further forward of the centre base point than that of the less-skilled batsmen. This forward head position was associated with the tendency for the skilled batsmen's centre of mass to be further forward during the predicted bat–ball contact. There were no significant differences between groups in the shoulder angle, bat angle or bat speed during the different phases of the stroke. There was a tendency for the less-skilled batsmen to have a larger hip angle at contact. This study provides further understanding of the factors associated with skilled performance in cricket batting, which coaches should consider when training less-skilled performers. 相似文献
8.
Rob Gray 《Research quarterly for exercise and sport》2013,84(3):491-501
Bat/ball contact produces visual (the ball leaving the bat), auditory ( the “crack” of the bat), and tactile (bat vibration) feedback about the success of the swing. We used a batting simulation to investigate how college baseball players use visual, tactile, and auditory feedback. In Experiment 1, swing accuracy (i.e., the lateral separation between the point of contact and “sweet spot”) was compared for no feedback (N), visual alone, auditory alone, and tactile alone. Swings were more accurate for all single-modality combinations as compared to no feedback, and visual produced the greatest accuracy. In Experiment 2, the congruency between visual, tactile, and auditory was varied so that in some trials, the different modalities indicated that the simulated ball contacted the bat at different points. Results indicated that batters combined information but gave more weight to visual. Batting training manuals, which typically only discuss visual cues, should emphasize the importance of auditory and tactile feedback in baseball batting. 相似文献
9.
Hitting a cricket ball: what components of the interceptive action are most linked to expertise? 总被引：1，自引：0，他引：1
Weissensteiner JR Abernethy B Farrow D 《Sports biomechanics / International Society of Biomechanics in Sports》2011,10(4):324-338
Differences in interceptive skill between highly skilled and lesser skilled cricket batsmen were examined using a batting task that required participants to strike front-foot drive strokes from a machine-projected ball to a specified target. Task difficulty was manipulated by varying the width of the bat (normal, half, and third width) and target accuracy, and quality of bat-ball contact was monitored along with temporal and sequential elements of the hitting action. Analyses revealed that the highly skilled batsmen were distinguishable from less skilled counterparts by their higher accuracy under the normal and half-width bat conditions, significantly earlier initiation and completion of the front-foot stride, greater synchronization of the completion of the front-foot stride with the commencement of the downswing of the bat, and consistent timing of downswing relative to ball bounce and impact. In keeping with studies of other hitting sports, temporal and spatial coupling of the downswing to ball bounce to help minimize temporo-spatial error at the point of interception appeared critical to skilled performance. Implications for the understanding of interception and for coaching practice are briefly discussed. 相似文献
10.
The dynamic properties of six types of tennis balls were measured using a force platform and high-speed digital video images of ball impacts on rigidly clamped tennis rackets. It was found that the coefficient of restitution reduced with velocity for impacts on a rigid surface or with a rigidly clamped tennis racket. Pressurized balls had the highest coefficient of restitution, which decreased by 20% when punctured. Pressureless balls had a coefficient of restitution approaching that of a punctured ball at high speeds. The dynamic stiffness of the ball or the ball-racket system increased with velocity and pressurized balls had the highest stiffness, which decreased by 35% when punctured. The characteristics of pressureless balls were shown to be similar to those of punctured balls at high velocity and it was found that lowering the string tension produced a smaller range of stiffness or coefficient of restitution. It was hypothesized that players might consider high ball stiffness to imply a high coefficient of restitution. Plots of coefficient of restitution versus stiffness confirmed the relationship and it was found that, generally, pressurized balls had a higher coefficient of restitution and stiffness than pressureless balls. The players might perceive these parameters through a combination of sound, vibration and perception of ball speed off the racket. 相似文献
11.
陈德林 《沈阳体育学院学报》2006,25(4):109-110
在新规则背景下,探索出乒乓球战术训练的落点监控方法,即将球台划分为3个大区、15个小区,并做出标志,使学生根据不同的战术要求,将球击到相应的区域内,并进行了教学实验。实验结果显示:乒乓球战术训练的落点监控法便于直观教学及击球动作的动力定型,在提高战术训练质量、实战能力方面明显优于常规教法。 相似文献
12.
Abstract The dynamic properties of six types of tennis balls were measured using a force platform and high-speed digital video images of ball impacts on rigidly clamped tennis rackets. It was found that the coefficient of restitution reduced with velocity for impacts on a rigid surface or with a rigidly clamped tennis racket. Pressurized balls had the highest coefficient of restitution, which decreased by 20% when punctured. Pressureless balls had a coefficient of restitution approaching that of a punctured ball at high speeds. The dynamic stiffness of the ball or the ball-racket system increased with velocity and pressurized balls had the highest stiffness, which decreased by 35% when punctured. The characteristics of pressureless balls were shown to be similar to those of punctured balls at high velocity and it was found that lowering the string tension produced a smaller range of stiffness or coefficient of restitution. It was hypothesized that players might consider high ball stiffness to imply a high coefficient of restitution. Plots of coefficient of restitution versus stiffness confirmed the relationship and it was found that, generally, pressurized balls had a higher coefficient of restitution and stiffness than pressureless balls. The players might perceive these parameters through a combination of sound, vibration and perception of ball speed off the racket. 相似文献
13.
Lloyd V. Smith 《Sports Engineering》2014,17(3):123-130
This study considered the effect of temperature and relative humidity on the performance of softballs, baseballs and bats. The balls were conditioned in constant humidity and temperature environments and then impacted against a rigidly supported load cell from which the ball coefficient of restitution and stiffness were obtained. The balls reached steady state temperature on the order of a few minutes, while steady state humidity required upwards of 2 weeks. Ball stiffness and coefficient of restitution tended to decrease with increasing humidity. Increasing temperature generally caused ball stiffness to decrease and the coefficient of restitution to increase. Balls made from synthetic materials tended to resist the effects of moisture, but showed an increased sensitivity to temperature. The effect of temperature and humidity on bat performance (sign and magnitude) depended on the design of the ball and bat. The largest effect occurred in professional baseball, where for a long fly ball, decreasing the temperature by 33 °C and lowering the relative humidity from 90 to 10 % resulted in a 5 m decrease and a 15 m increase in hit distance, respectively. 相似文献
14.
Valerie Fayt Reinoud J. Bootsma Ronald G. Marteniuk Christine L. Mackenzie Michel Laurent 《Journal of sports sciences》2013,31(6):581-586
In the light of the intensity coupling effects reported in the literature, subjects' capacities for independently controlling the absolute velocity of their movement at the point of interception was evaluated by asking them to learn to propel orthogonally approaching balls, varying in their speed of approach, into target boxes placed at various distances from the interception point. As required for successful accomplishment of the task, movement velocity was found to be adapted to the distance to be covered, with the near target giving rise to lower velocities and the far target giving rise to higher velocities even when the conditions were presented in random order. Nevertheless, even though target distance accounted for a substantial proportion of the total variance, a small but significant effect of ball approach speed on movement velocity was found, suggesting that intensity coupling is a persistent but modulable phenomenon in interception tasks. 相似文献
15.
Daniel T. Bishop Neil Addington Giorgia D’Innocenzo 《European Journal of Sport Science》2017,17(2):160-167
Eye movements are essential for both predictive and reactive control of complex motor skills such as the golf swing. We examined the use of a visually guided learning protocol to retrain an experienced golfer’s point-of-gaze immediately prior to execution of the full golf swing; his swing, and his gaze behaviour, had become established over more than a decade of practice and competition. Performance and eye movement data were obtained, from baseline, through intervention, to retention, for a total of 159 shots struck at a target 200 yards away. Results show that, at baseline, not only was the golfer’s point-of-gaze not at the intended/predicted location, at the top-rear of the ball, but there was also high trial-to-trial variability. A bespoke visual guidance protocol improved his gaze behaviour considerably, in terms of accuracy and consistency – and this was reflected in accuracy and consistency of his shots. Implications of oculomotor interventions for the relearning of established motor skills are discussed. 相似文献
16.
Abstract The purpose of this study was to examine the mechanics of hitting a baseball to the same and opposite fields. Twenty male subjects were assigned to one of two groups according to their baseball hitting abilities. Each subject performed as many trials as were necessary to successfully hit a pitched ball three times to both the same and opposite fields. Each trial was filmed from above. No significant interactions (p < 0.05) were found between subject groups and field hits with selected temporal and kinematic parameters entered as dependent variables. Significant differences (p < 0.05) were found between body landmark and segment component displacements and velocities at the instant prior to ball contact. The maximum resultant linear and angular speed of the examined body and bat landmarks were found to occur prior to ball contact. Based on the results of the study it was concluded that no interactions exist between hitting ability and hitting technique when hitting to defined field areas and that differences in the mechanics of hitting to defined areas are due in part to: (1) differences in the angular displacements of the left wrist and left elbow joints and (2) differences in the temporal characteristics of the swings. 相似文献
17.
Handling errors are often seen in professional rugby games and even more so in amateur rugby. This paper analyses the problem
of ball mishandling using high-speed video footage of passes and a bespoke finger friction rig. The high-speed video analysis
showed that when the ball is caught, often there is a fluctuating movement of the fingers over the surface of the ball. It
also showed that the fingers move over the surface of the ball when the ball is thrown, confirming that the dynamic friction
is a good measure of how easily a ball can be handled. Rugby ball surface samples were used, on a finger friction rig, to
assess the coefficient of friction between the finger and the balls. The currently manufactured balls displaying the highest
coefficients of friction in clean, dry conditions were the design with square, ‘sharp’ pimples and also the design with a
mixture of small and large pimples. The most consistent ball across wet and dry conditions was the ball with round, large,
densely populated pimples. It was also shown that when water is added to the surface of the ball or finger, there was little
variation in performance between the ball varieties. 相似文献
18.
In rapid interceptive actions such as hitting a baseball, cricket ball or tennis ball, ball speed varies between trials, and players have to compensate the time lag by controlling the moment of movement onset and movement duration. Previous studies have found that these two variables can flexibly co-vary and are robustly influenced by target speed (i.e. velocity-coupling effect: faster movement for faster target). However, some studies reported an interpersonal variability in the timing control strategy and the relationship between the strategy and temporal accuracy in rapid interception is unclear. We used a baseball-simulated rapid interceptive task to assess this issue. Under relatively easy time constraints, there was a large interpersonal variability, and participants were distinctively divided into two groups: those who mainly modulated their movement duration and those who mainly controlled their movement onset. When the time constraint became severe, the second strategy shifted to the first strategy in most of the second group participants. In the both cases, being able to mainly control movement onset resulted in higher temporal accuracy. These results suggest that minimising the velocity-coupling effect is an important factor to achieve high temporal accuracy in rapid interception. 相似文献
19.
运用实验、数理统计和文献资料等研究方法,通过测试心率、血乳酸、血尿素、尿蛋白等生理生化指标,对两种网球多球训练效果进行比较,阐述了多球训练在网球运动中的具体应用,旨在为网球教学提供参考与借鉴。结果表明:4球×12组的网球多球练习,着重发展运动员的糖酵解供能系统,时间结构与网球比赛实际运用一致,训练更有实用性。16球×3组的网球多球训练,着重发展运动员糖酵解供能系统,有助于提高运动员的乳酸耐受力,促使运动员在大强度比赛中保持技术动作的完整性。 相似文献
20.
Head, eye and arm coordination in table tennis 总被引：1，自引：0，他引：1
The aim of this study was to determine the role of head, eye and arm movements during the execution of a table tennis forehand stroke. Three-dimensional kinematic analysis of line-of-gaze, arm and ball was used to describe visual and motor behaviour. Skilled and less skilled participants returned the ball to cued right or left target areas under three levels of temporal constraint: pre-, early- and late-cue conditions. In the pre- and early-cue conditions, both high and low skill participants tracked the ball early in flight and kept gaze stable on a location in advance of the ball before ball-bat contact. Skilled participants demonstrated an earlier onset of ball tracking and recorded higher performance accuracy than less skilled counterparts. The manipulation of cue condition showed the limits of adaptation to maintain accuracy on the target. Participants were able to accommodate the constraints imposed by the early-cue condition by using a shorter quiet eye duration, earlier quiet eye offset and reduced arm velocity at contact. In the late-cue condition, modifications to gaze, head and arm movements were not sufficient to preserve accuracy. The findings highlight the functional coupling between perception and action during time-constrained, goal-directed actions. 相似文献