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1.
The importance of effector visual feedback has previously been indicated using an opaque screen to prevent sight of the catching hand for the final 150-200 ms of a flight path of 850 ms in total. Attention was drawn to the finding that the ability to position the arm correctly in the line of flight of the ball deteriorated as a consequence of the number of trials without visual feedback. However, the use of only 20 test trials allows a possibility that the proprioceptive system may be able to re-establish predominant control under conditions of prolonged visual decrement. In order to verify this notion, the number of experimental trials was quadrupled for 24 subjects of mixed sex in a replication of the initial paradigm. The results provided preliminary support for the view that the positioning of the catching arm is more seriously affected by visual occlusion than the timing of the grasp phase. However, increments in accuracy of limb orientation were evidenced in all screen conditions, as the number of trials increased. The grasp component of one-handed catching appeared to remain unaffected by the increase in experimental trials. The relative influence of skill level on catching errors was next addressed by comparing the performance of the six best and worst catchers in the group. The results did not support previous research which found a relation between skill level and error type. The number of position, but not grasp, errors decreased as a function of task practice for both subgroups. Future investigations should, perhaps, focus on the developmental nature of movement control in one-handed catching to obtain a clearer picture of this relation. 相似文献
2.
The influence of a baseball glove on the positioning and grasping components of one-hand catching was studied under both vision impaired and unimpaired conditions. Skilled softball and baseball players (N = 20) caught tennis balls barehand and softballs with a fielder's glove. In half of the trials, a screen positioned alongside the subject's head blocked vision of the catching hand. All trials were videotaped and errors were categorized by type (position or grasp). Results indicated that with the glove performance was essentially perfect, regardless of the screen condition. Barehand grasping performance, however, was affected by the subject's inability to see his hand to a much greater extent than barehand positioning. We argue that the baseball glove functions to reduce both the positioning accuracy requirements and the grasp timing requirements in simple catching. Peripheral vision of the limb, however, is necessary for controlling the barehand grasp phase. 相似文献
3.
Hui-Ting Goh Shailesh S. Kantak Katherine J. Sullivan 《Research quarterly for exercise and sport》2013,84(2):346-352
Reduced feedback during practice has been shown to be detrimental to movement accuracy in children but not in young adults. We hypothesized that the reduced accuracy is attributable to reduced movement parameter learning, but not pattern learning, in children. A rapid arm movement task that required the acquisition of a motor pattern scaled to specific spatial and temporal parameters was used to investigate the effects of feedback (FB) frequency (100% vs. 62% faded) on motor learning differences between 19 school-age children and 19 young adults. Adults and children practiced the task for 200 trials under the 100% or faded FB condition on Day 1 and returned on Day 2 for a no-FB retention test. On the retention test, children who practiced with reduced feedback performed with greater temporal parameter errors, but not pattern error, than children who received frequent feedback. Motor skill learning in children is influenced by feedback frequency during practice that affects parameter learning but not pattern learning. 相似文献
4.
Abstract The purpose of this study was to determine the coding characteristics of kinesthetic location information acquired during learning trials. Forty-eight blindfolded subjects learned to make a linear response with the right hand to a criterion location during 13 trials. Upon completion of the learning trials, subjects performed 10 trials without knowledge of results (KR) under one of four treatment conditions which were defined by the limb used and the dominant source of feedback available. Specifically, the conditions were right-hand control with kinesthetic feedback, left-hand kinesthetic, right-hand visual, and left-hand visual. The results of the ANOVAs for absolute error (AE) and constant error (CE) from the no-KR trials revealed that the visual feedback groups made significantly greater response errors than did the kinesthetic feedback groups. The blocks main effect for CE was also significant. Analysis of variable error (VE) indicated that the visual feedback groups were significantly more consistent in their responses than were the kinesthetic feedback groups. Within a motor learning paradigm, the concept of a spatial-location coordinate system was supported by the similar performances of the right-handed and left-handed groups. A discrepancy in this system was identified when visual feedback was provided for controlling the response to a location previously learned with kinesthetic cues. 相似文献
5.
Raôul R. D. Oudejans Sjoerd Heubers Jean-René J. A. C. Ruitenbeek Thomas W. J. Janssen 《Research quarterly for exercise and sport》2013,84(3):464-469
We examined the effects of visual control training on expert wheelchair basketball shooting, a skill more difficult than in regular basketball, as players shoot from a seated position to the same rim height. The training consisted of shooting with a visual constraint that forced participants to use target information as late as possible. Participants drove under a large screen that initially blocked the basket. As soon as they saw the basket they shot. When training with the screen, shooting percentages increased. We conclude that visual control training is an effective method to improve wheelchair basketball shooting. The findings support the idea that perceptualmotor learning can be enhanced by manipulating relevant constraints in the training environment, even for expert athletes. 相似文献
6.
Reduced feedback during practice has been shown to be detrimental to movement accuracy in children but not in young adults. We hypothesized that the reduced accuracy is attributable to reduced movement parameter learning but not pattern learning in children. A rapid arm movement task that required the acquisition of a motorpattern scaled to specific spatial and temporal parameters was used to investigate the effects of feedback (FB) frequency (100% vs. 62% faded) on motor learning differences between 19 school-age children and 19 young adults. Adults and children practiced the task for 200 trials under the 100% or faded FB condition on day 1 and returned on day 2 for a no-FB retention test. On the retention test, children who practiced with reduced feedback performed with greater temporal parameter errors, but not pattern error than children who received frequent feedback. Motor skill learning in children is influenced byfeedback frequency during practice that affects parameter learning but not pattern learning. 相似文献
7.
Abstract The present study attempted to determine whether the nature of training experiences influences the development of coincident timing skill in young children. The task involved visual tracking of a moving light sequence and a 43 cm arm movement to a padded target. Subjects attempted to tap the target coincident with the completion of the light sequence. Sixty first grade children were randomly assigned to one of five groups, with an equal number of males and females in each group. Subjects assigned to the training groups received 48 trials on each of two days, with stimulus speeds that were either slow (179 cm/sec or 4 mph), fast (313 cm/sec or 7 mph), varied-random (179, 224, 268, 313 cm/sec or 4, 5, 6, 7 mph), or varied-blocked (i.e., 6 consecutive trials with one speed before changing to another). Control subjects performed a neutral coloring activity during the training phase of the experiment. All subjects were then given 10 trials on a third day with each of two stimulus speeds not experienced previously; one slow (134 cm/sec or 3 mph) and one fast (358 cm/sec or 8 mph). During transfer trials all groups were more accurate with the fast than with the slow speed stimulus. Training method mattered most during slow speed transfer trials, with the most accurate performance demonstrated by the group receiving varied-blocked speeds during training. The least effective methods were fast speed training, especially for males, and varied-random speed training. It was concluded that training sessions for the development of coincident timing skill in young children should emphasize slower speed stimuli and blocking of additional speeds which are more rapid. 相似文献
8.
Margaret Robb 《Research quarterly for exercise and sport》2013,84(1):175-184
Abstract This study was an investigation of the course of learning a specified arm movement pattern under conditions that varied as to the type and frequency of feedback information. After several days of practice, subjects performed a criterion test which was the same as the learning movement pattern, but explicit visual feedback was withdrawn. Forty undergraduate students were divided into five groups. Each group was randomly assigned a method of learning the task. The methods of receiving information about performance were as follows: (a) concurrent visual feedback, (b) concurrent proprioceptive feedback and terminal knowledge of graphs, (c) a combination of (a) and (b), (d) concurrent visual feedback interspersed with passive watching, and (e) concurrent visual feedback at two different speeds. The results indicated the following: (a) the most effective variable for learning the pattern was concurrent visual feedback, (b) performing the movement at a slower than normal rate was detrimental to performance on the criterion test, (c) sitting and watching was as effective a learning method as performing at two speeds, and (d) subjects in the slow-standard speed group were significantly poorer than subjects in other groups during performance of the criterion test. The other methods did not differ significantly from each other. 相似文献
9.
Ken Purcell 《Research quarterly for exercise and sport》2013,84(2):238-245
Abstract A tennis skill test for use in quantifying achievement in the forehand and backhand drive strokes was developed and then validated using 76 college women enrolled in beginning tennis classes. The test consisted of returning balls pitched by a pneumatic ball machine into target areas drawn in chalk on a regulation tennis court. Speed of the subjects' shots was assessed by measuring accumulated time in flight for rounds of 10 trials using a stopwatch. A time factor was then employed to correct the target value total for the trials to adjust for ball speed, thus rewarding the more skilled player who could stroke the ball more firmly while still retaining control. The test-retest reliability of the test was found to be .84, while the validity of the test, using judges' ratings as a criterion, was .83. It was concluded that the test was a valid and reliable test of skill which was closely related to the actual game situation. Percentile norms were developed on a limited number of subjects. 相似文献
10.
运动技能控制与学习领域中追加反馈的研究始终是国内外学者研究的重要课题,而追加反馈中的表现反馈更是学者们研究的焦点问题。运用文献资料法、实验法和数理统计法等,架构于乒乓球正手发下旋球这项运动技能,对参与该项运动技能的学习者施加100%相对频率的视觉方式表现反馈和33%相对频率的视觉方式表现反馈。结果表明:①在运动技能学习阶段采用视觉方式表现反馈指导运动技能,高频率视觉反馈组的绩效好于低频率视觉反馈组;②在运动技能3min保留阶段采用视觉方式表现反馈指导运动技能,视觉高频率反馈组的绩效好于视觉低频率反馈组;③在运动技能48h保留阶段采用视觉方式表现反馈指导运动技能,视觉高频率反馈组的绩效与视觉低频率反馈组的绩效无显著性差异。 相似文献
11.
Bruce Abernethy 《Journal of sports sciences》2013,31(1):17-34
The time of occurrence and spatial location of the advance cues used to anticipate the direction and force of an opponent's stroke in squash were examined using a film task. This task, designed to simulate the normal perceptual display of the defensive player, consisted of two discrete parts, each containing 160 individual stroke sequences (trials). In the first part of the film task, the display was occluded at different time intervals throughout the development of the opponent's stroke and the 16 expert and 20 novice subjects had to predict both the direction (down‐wall or cross‐court) and force (drive or drop shot) of the opponent's stroke. In the second part of the film task, visibility to selected advance cues was occluded by placing opaque mats on the film surface. Across all of the film task conditions experts were superior to novices in predicting the event outcome from the information available, highlighting the important contribution anticipatory skills make to expert performance in this sport. Analysis of lateral (direction) error showed that the most critical time periods for extracting information about stroke direction are the periods between 160–80 ms prior to racket‐ball contact and the period of extended ball flight arising at least 80 ms after contact. Whereas both groups were attuned to this ball flight information, only the experts were capable of picking up information from the early part of the opponent's actions. This early information appeared to be provided by the opposing player's arm action. Similar time periods were found to be also important for the prediction of stroke depth, but in this case both experts and novices were similar in their cue dependence. 相似文献
12.
Abstract This paper examines whether self-controlled feedback schedules enhance learning, because they are more tailored to the performers' needs than externally controlled feedback schedules. Participants practiced a sequential timing task. One group of learners (self-control) was provided with feedback whenever they requested it, whereas another group (yoked) had no influence on the feedback schedule. The self-control group showed learning benefits on a delayed transfer test. Questionnaire results revealed that self-control learners asked for feedback primarily after good trials andyoked learners preferred to receive feedback after good trials. Analyses demonstrated that errors were lower on feedback than no-feedback trials for the self-control group but not for the yoked group. Thus, self-control participants appeared to use a strategy for requesting feedback. This might explain learning advantages of self-controlled practice. 相似文献
13.
S Bennett C Button D Kingsbury K Davids 《Research quarterly for exercise and sport》1999,70(3):220-232
Previous motor learning studies examining the effects of practicing to catch one-handed under varying informational constraints on subsequent skill acquisition are equivocal, perhaps due to the use of relatively inexperienced adult participants. Ecological theory predicts that directing the learner's search for information in the perceptual-motor workspace can enhance skill acquisition. This study manipulated visual informational constraints on novice children (ages 9-10 years) learning to catch one-handed. A crossover transfer design was implemented in which one group acted as controls while two other groups practiced either without visual restrictions before transferring to full vision, or vice versa. The data indicated that learners forced to seek additional information sources under restricted viewing conditions demonstrated a greater positive, accumulative residual effect on acquiring a catching skill. The findings contradict current work on the specificity of practice hypothesis and suggest that varying visual informational constraints to encourage exploratory practice may represent a significant pedagogical approach to motor learning in sport. 相似文献
14.
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
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Abstract Effects of movement context upon the encoding of kinesthetic spatial location information were examined in a series of experiments using a motor learning paradigm. A cross-modal, kinesthetic to kinesthetic plus visual feedback procedure was used in each experiment to determine the encoding characteristics of spatial information within a variety of movement conditions. Following knowledge of results trials, subjects performing in cross-modal conditions had significant directional errors (overshooting of the target) for spatial locations associated with specific and non-specific body-referents (Experiment 1), for different movement directions to the same target (Experiment 2), and for long (40 cm) movements (Experiments 2, 3) and short (15 cm) movements (Experiment 4). However, subjects in both intermodal and intramodal conditions who switched movement direction had significant undershooting of the spatial targets (Experiment 3). Movement context in terms of response endpoint location or movement length did not have an apparent effect on directional errors. Performances in all experimental conditions were biased in the direction of the movement during learning. The context provided by movement direction did influence the encoding of kinesthetic spatial information. 相似文献
18.
Thomas Reilly 《Journal of sports sciences》2013,31(1):1-2
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
19.
Three-dimensional kinematic analysis of line of gaze, arm and ball was used to describe the visual and motor behaviour of male adolescents diagnosed with attention deficit hyperactivity disorder (ADHD). The ADHD participants were tested when both on (ADHD-On) and off (ADHD-Off) their medication and compared to age-matched normal controls in a modified table tennis task that required tracking the ball and hitting to cued right and left targets. Long-duration information was provided by a pre-cue, in which the target was illuminated approximately 2 s before the serve, and short-duration information by an early-cue illuminated about 350 ms after the serve, leaving approximately 500 ms to select the target and perform the action. The ADHD groups differed significantly from the control group in both the pre-cue and early-cue conditions in being less accurate, in having a later onset and duration of pursuit tracking, and a higher frequency of gaze on and off the ball. The use of medication significantly reduced the gaze frequency of the ADHD participants, but surprisingly this did not lead to an increase in pursuit tracking, suggesting a barrier was reached beyond which ball flight information could not be processed. The control and ADHD groups did not differ in arm movement onset, duration and velocity in the short-duration early-cue condition; in the long-duration pre-cue condition, however, the ADHD group's movement time onset and arm velocity differed significantly from controls. The results show that the ADHD groups were able to process short-duration information without experiencing adverse effects on their motor behaviour; however, long-duration information contributed to irregular movement control. 相似文献
20.
Chris Grant Tyson A. C. Beach Sheilah Hogg-Johnson Michael Chivers 《Measurement in physical education and exercise science》2020,24(1):81-92
ABSTRACTThis study evaluated whether real-time applied load feedback and a predefined applied load limit improved inter-session reliability and measurement error of passive glenohumeral rotation range-of-motion measurements. Twenty-one male recreational overhead athletes completed two data collection sessions, approximately 1-week apart. Measurements of internal and external rotation range-of-motion and clinician-applied loads were obtained and side-to-side differences were calculated. A load limit of 4 Nm was used for feedback trials. Perception of a capsular end-feel was used for no-feedback trials. Intraclass correlation coefficients (ICCs), standard errors of measurement (SEMs) and minimal detectable changes (MDCs) were derived. ICCs from single trials with and without feedback ranged from 0.72–0.93 and 0.63–0.89, respectively. SEMs ranged from 2.6°-6.1° with feedback and 3.3°-6.0° without feedback. MDCs from single trials with and without feedback ranged from 7.2°-16.8° and 9.1°-16.7°, respectively. Applied load feedback did not improve, already moderate to excellent, inter-session reliability and SEM for passive glenohumeral rotation range-of-motion measurements. 相似文献