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1.
Abstract

A test of motor stage theory was conducted to screen cross-sectionally for the existence of “horizontal structure” among motor sequences within four movement components of overarm throwing and overarm striking for force. A total of 58 male subjects were filmed performing five trials of each task. Comparisons were made between movement component sequence levels as assessed by Roberton's Component Category Checklist for the Overarm Throw and Langendorfer's Component Category Checklist for Overarm Striking. Results indicated that longitudinal study of sequences within the components of trunk, humerus, forearm-racquet actions was warranted and that intertask comparisons of motor sequences were best represented by combinations of stage models proposed by Wohlwill (1973). The observed movement commonalities in the present data were consistent with constructs in both Piagetian developmental stage theory and Schmidt's schema theory in motor control and learning.  相似文献   

2.
The purposes of this study were to: (a) examine the differences within 11 specific kinematic variables and an outcome measure (ball velocity) associated with component developmental levels of humerus and forearm action (Roberton & Halverson, 1984), and (b) if the differences in kinematic variables were significantly associated with the differences in component levels, determine potential kinematic constraints associated with skilled throwing acquisition. Significant differences among component levels in five of six humerus kinematic variables (p <.01) and all five forearm kinematic variables (p < .01) were identified using multivariate analysis of variance. These kinematic variables represent potential control parameters and, therefore, constraints on overarm throwing acquisition.  相似文献   

3.
The purposes of this study were to: (a) examine differences within specific kinematic variables and ball velocity associated with developmental component levels of step and trunk action (Roberton & Halverson, 1984), and (b) if the differences in kinematic variables were significantly associated with the differences in component levels, determine potential kinematic constraints associated with skilled throwing acquisition. Results indicated stride length (69.3 %) and time from stride foot contact to ball release (39. 7%) provided substantial contributions to ball velocity (p < .001). All trunk kinematic measures increased significantly with increasing component levels (p < .001). Results suggest that trunk linear and rotational velocities, degree of trunk tilt, time from stride foot contact to ball release, and ball velocity represented potential control parameters and, therefore, constraints on overarm throwing acquisition.  相似文献   

4.
The purposes of this study were to: (a) examine the differences within 11 specific kinematic variables and an outcome measure (ball velocity) associated with component developmental levels of humerus and forearm action (Roberton & Halverson, 1984), and (b) if the differences in kinematic variables were significantly associated with the differences in component levels, determine potential kinematic constraints associated with skilled throwing acquisition. Significant differences among component levels in five of six humerus kinematic variables (p < .01) and all five forearm kinematic variables (p < .01) were identified using multivariate analysis of variance. These kinematic variables represent potential control parameters and, therefore, constraints on overarm throwing acquisition.  相似文献   

5.
The purposes of this study were to: (a) examine differences within specific kinematic variables and ball velocity associated with developmental component levels of step and trunk action (Roberton & Halverson, 1984), and (b) if the differences in kinematic variables were significantly associated with the differences in component levels, determine potential kinematic constraints associated with skilled throwing acquisition. Results indicated stride length (69.3%) and time from stride foot contact to ball release (39.7%) provided substantial contributions to ball velocity (p < .001). All trunk kinematic measures increased significantly with increasing component levels (p < .001). Results suggest that trunk linear and rotational velocities, degree of trunk tilt, time from stride foot contact to ball release, and ball velocity represented potential control parameters and, therefore, constraints on overarm throwing acquisition.  相似文献   

6.
According to recent motor control studies, it is important to know probabilistic structure of his/her own motor errors to choose an optimal motor plan (i.e., where you aim at) to maximise the expected gain. In this study, we questioned if pitching form determines the probabilistic structure of pitching errors in baseball pitchers. Eighteen collegiate baseball pitchers with various pitching forms including right- and left-handed overarm, sidearm and underarm throwers threw 100 pitches aiming at a target located 90 cm above the ground. Two dimensional distribution of pitch location was fitted by using bivariate normal distribution and 95% confidence ellipse was calculated. In order to quantify the pitching form, the direction of the throwing arm trajectory in frontal plane was calculated. The direction of the long axis was dependent on each participant’s pitching form (e.g., right overarm pitchers pitched along a right-up–left-down ellipse and left overarm pitchers pitched along a left-up–right-down ellipse). This was confirmed by circular correlation analysis (P = 0.98). These results suggest that different mechanisms, potentially errors in pitching mechanics and errors in ball release timing, might contribute to errors along the long axis and those along the short axis.  相似文献   

7.
This paper considers the kinematic characteristics of overarm throwing with particular emphasis on the techniques of throwing and pitching in baseball. The technique is subdivided into: (1) sequential pattern of throwing, (2) lead foot contact, (3) preparatory phase, (4) arm acceleration and (5) instant of ball release. Specific biomechanical principles that underpin throwing and their application within baseball are identified. The paper also presents a case study of the three-dimensional characteristics of throwing technique in cricket. The aim was to compare the skill in cricket to that previously researched in baseball. The findings for throwing in cricket are similar to those reported for baseball, indicating that there is a definite crossover in the rationale of how an individual should throw specific to the demands of cricket and baseball. The differences noted--greater elbow flexion at lead foot contact and less external rotation during the preparation phase--can be attributed to the demands placed on the fielder and pitcher specific to their respective sports.  相似文献   

8.
Abstract

Children studied longitudinally from kindergarten through second grade were refilmed in seventh grade as they performed 10 trials of the forceful overarm throw. The horizontal ball velocities of the 22 boys and the 17 girls were compared with predictions made when the children were in second grade. The original estimate of an annual rate of change (a “developmental year”) of 5–8 feet/sec/year (1.52–2.44m) remained accurate for the boys; the original estimate for the girls had to be increased to 2–4.5 feet/sec/year (.61–1.37m). While the gap between the sexes increased throughout elementary school, it increased at a slower rate from second to seventh grade than it had during the primary years. By seventh grade, however, the girls were 5 developmental years behind the boys. The data also suggested a difference in the degree to which the sexes maintained their relative positions within their groups: girls appeared more stable than boys across the elementary years. Change was also assessed in the developmental levels exhibited by the children as they threw. The girls' rate of development was 5–6 years behind the boys' rate. Few boys, however, had reached an advanced level in all movement components by seventh grade. Self-reports suggested that the boys had participated in more overarm throwing than had the girls.  相似文献   

9.
10.
Biomechanical energetic analysis of technique can be performed to identify limits or constraints to performance outcome at the level of joint work, and to assess the mechanical efficiency of techniques. The aim of this study was to investigate the biomechanical energetic processes during learning the longswing on the high bar. Twelve male, novice participants took part in a training study. Kinematic and kinetics data were collected during swing attempts in eight weekly testing sessions. Inverse dynamics analysis was performed from known zero forces at the toes. Joint work, total energy, and bar energy were calculated. Biomechanical constraints to action, that is, limits to novice performance, were identified as “total work” and “shoulder work”. The most biomechanically efficient technique was associated with an onset of the hip functional phase and joint work that occurred between 10–45° before the bottom of the swing. The learning of gross motor skills is realised through the establishment of a set of techniques with task specific biomechanical constraints. Knowledge of the biomechanical constraints to action associated with more effective and efficient techniques will be useful for both assessing learning and establishing effective learning interventions.  相似文献   

11.
The purpose of this study was to investigate joint kinetics of the throwing arms and role of trunk motion in skilled elementary school boys during an overarm distance throw. Throwing motions of 42 boys from second, fourth, and sixth grade were videotaped with three high-speed cameras operating at 300 fps. Seven skilled boys from each grade were selected on the basis of throwing distance for three-dimensional kinetic analysis. Joint forces, torques, and torque powers of the throwing arm joints were calculated from reconstructed three-dimensional coordinate data smoothed at cut-off frequencies of 10.5–15 Hz and by the inverse dynamics method. Throwing distance and ball velocity significantly increased with school grade. The angular velocity of elbow extension before ball release increased with school grade, although no significant increase between the grades was observed in peak extension torque of elbow joint. The joint torque power of shoulder internal/external rotation tended to increase with school grade. When teaching the overarm throw, elementary school teachers should observe large backward twisting of trunk during the striding phase and should keep in mind that young children, such as second graders (age 8 years), will be unable to effectively utilise shoulder external/internal rotation during the throwing phase.  相似文献   

12.
We examined the role of rotation axes during an overarm throwing task. Participants performed such task and were asked to throw a ball at maximal velocity at a target. The purpose of this study was to examine whether the minimum inertia axis would be exploited during the throwing phases, a time when internal–external rotations of the shoulder are particularly important. A motion capture system was used to evaluate the performance and to compute the potential axes of rotation (minimum inertia axis, shoulder–centre of mass axis and the shoulder–elbow axis). More specifically, we investigated whether a velocity-dependent change in rotational axes can be observed in the different throwing phases and whether the control obeys the principle of minimum inertia resistance. Our results showed that the limbs’ rotational axis mainly coincides with the minimum inertia axis during the cocking phase and with the shoulder–elbow axis during the acceleration phase. Besides these rotation axes changes, the use of interaction torque is also sequence-dependent. The sequence-dependent rotation axes changes associated with the use of interaction torque during the acceleration phase could be a key factor in the production of hand velocity at ball release.  相似文献   

13.
Some studies have reported that overarm baseball pitching shows a proximal to distal sequential joint motion including a rapid extension of the elbow. It has been suggested that the rapid elbow extension just before ball release is not due to the action of the elbow extensor muscles, but the underlying mechanisms are not so clear. The purpose of this study was to determine the contributions of each joint muscular- and motion-dependent torques, including the upper trunk and throwing arm joints to generate the rapid elbow extension during baseball pitching. The right handed throwing motions of three baseball pitchers were recorded using five high-speed video cameras and the positional data were calculated using the direct linear transformation method. A throwing arm dynamic model of the upper trunk and throwing arm joints was then used, including 10 degrees of freedom, to calculate the throwing arm joint muscular-, throwing arm and upper trunk joint motion-, gravity-, and external force-dependent components that contribute to the maximum elbow extension angular velocity. The results showed that the rapid elbow extension was primarily due to the upper trunk counterclockwise rotation and shoulder horizontal adduction angular velocity-dependent torques. This study implied that the trunk counterclockwise rotators and shoulder horizontal adductors generate positive torques to maintain the angular velocities of the upper trunk counterclockwise rotation and shoulder horizontal adduction may play a key role in producing the rapid elbow extension.  相似文献   

14.
When characterising typical human movement profiles, the optimal number of trials analysed for each participant should ensure a stable mean. Sequential analysis is one method able to establish the number of trials to stability by assessing a moving point mean against a set bandwidth. As the total trial number determining this bandwidth is selected arbitrarily, the effect of applying different total trial numbers on the results of sequential analysis was investigated. Twenty participants performed 30 trials of overarm throwing, and sequential analyses were applied to three dimensional (3-D) kinematic data over 10, 20 and 30 trial numbers. We found a total of 20 to be the preferred trial number for sequential analyses. Erroneous results were produced consistently by 10 trial number groups, while moving point means were statistically unchanged after the 10th trial. Subsequently, sequential analyses were applied to 20 trials to establish trials to stability in discrete and time series elements of the 3-D kinematic data. The results suggest that a trial size between 13 and 17 provides stable means for overarm throwing kinematics.  相似文献   

15.
Abstract

The study had two aspects: To determine the effect of warm-up throwing drills (employing “systematic overload”) upon subsequent speed and accuracy of the overarm throw in subjects with widely differing maximum velocities, and to determine the effect of a 6-week overload training (in which the speed and accuracy emphases were systematically varied) upon the speed and accuracy of the overarm throw.

The 60 subjects in the short-range phase of the study, examining the immediate effect of overload warm-up, received experimental treatments consisting of 10-oz., 15-oz., and regulation ball warm-up. The 48 subjects who participated in the long-range or training phase of the study received progressive overload in conjunction with various speed and/or accuracy emphases.

Computer services for this study were granted by the University of Wisconsin Research Committee through funds provided by the National Science Foundation and the Wisconsin Alumni Research Foundation.

The results of the study indicated that performance differences in throwing speed and accuracy, of high and low velocity performers that take place immediately following overload warm-up were statistically not significant. The initial speed and/or accuracy emphasis that was given appeared to have little effect on subsequent performance. The results provided no evidence that the use of a weighted ball resulted in immediate or long-range improvements in throwing speed or in throwing accuracy.  相似文献   

16.
Abstract

Research examining the proximal-to-distal sequencing of segments of the body involved in overarm throwing has been equivocal: some studies have found support for the concept while others have not. The aim of the present study, therefore, was to determine if there is a proximal-to-distal sequence in the timing of the movements of joints and the distal endpoints of segments in overarm throwing. The three-dimensional kinematics of a penalty throw in experienced team handball players (n = 11) were recorded and analysed with regard to the timing of events. We analysed the timing of the maximal velocity of the distal endpoints of six segments and the maximal angular velocity in 11 joints, as well as the initiation of these joint movements. A temporal proximal-to-distal sequence was observed only for the initiation of the joint movements. No such sequence was found for maximal velocity of the joints and distal endpoints of segments.  相似文献   

17.
自我谈话对动作表现的影响是体育运动领域中自我谈话研究的主流方向。以往围绕自我谈话与动作表现关系的研究主要考察自我谈话功能类型与动作技能类型之间的匹配关系,较少关注自我谈话表述形式对动作技能表现的影响。因此,本研究在任务匹配假说的基础上,引入自我谈话显隐性(表述形式)这一维度,探讨自我谈话功能类型和表述形式与动作技能类型之间的匹配关系。基于此,本研究设计了2个实验,实验1考察自我谈话功能类型与表述形式对精细类动作技能(飞镖投掷)表现的影响,实验2考察自我谈话功能类型与表述形式对粗放类动作技能(握力)表现的影响。2个实验均为2因素混合设计,实验对象为80名男性本科生。实验结果表明,不发声指导型自我谈话有利于飞镖投掷任务表现,而发声指导型自我谈话有利于握力测试任务表现。本研究表明,指导型自我谈话有利于精细类动作技能表现,尤其是新手;发声自我谈话有利于粗放类动作技能表现,不发声自我谈话有利于精细类动作技能表现。  相似文献   

18.
We examined the relationship between competence in three fundamental motor skills (throwing, kicking, and jumping) and six measures of health-related physical fitness in young adults (ages 18–25). We assessed motor skill competence using product scores of maximum kicking and throwing speed and maximum jumping distance. A factor analysis indicated the 12-min run/walk, percent body fat, curl-ups, grip strength, and maximum leg press strength all loaded on one factor defining the construct of “overall fitness.” Multiple regression analyses indicated that the product scores for jumping (74%), kicking (58%), and throwing (59%) predicted 79% of the variance in overall fitness. Gender was not a significant predictor of fitness. Results suggest that developing motor skill competence may be fundamental in developing and maintaining adequate physical fitness into adulthood. These data represent the strongest to date on the relationship between motor skill competence and physical fitness.  相似文献   

19.
Baseball     
Efficient, sequential timing is essential for upper level pitching. Interestingly, pitchers vary considerably in timing related elements of pitching style including pelvis rotation, arm cocking, stride leg behaviour, and pitch delivery time. The purpose of this study was to determine whether relationships exist among these elements by examining the overall style of pitchers exhibiting different pelvis rotation patterns. Pitching styles were defined by pelvis orientation at the instant of stride foot contact. Pitchers demonstrating a pelvis orientation greater than 30° were designated as ‘early rotators’, while pitchers demonstrating a pelvis orientation less than 30° were designated as ‘late rotators’. Kinematic and temporal differences were associated with the two styles. During the arm cocking phase, early rotators showed significantly greater shoulder external rotation at the instant of stride foot contact, earlier occurrence of maximum pelvis rotation angular velocity, and shorter time taken to complete the phase. However, by the instant of maximum shoulder external rotation, early and late rotators appeared remarkably similar as no significant difference occurred in pelvis and arm orientations. Therefore, it appears that early and late rotators used different methods to achieve similar results, including throwing velocity. Significant differences in throwing arm kinetics were also found for 10 of the 11 measures in the study. As the pelvis assumed a more open position at stride foot contact, maximum kinetic values were found to both decrease in magnitude and occur at an earlier time within the pitch.  相似文献   

20.
Influence of pelvis rotation styles on baseball pitching mechanics   总被引:1,自引:0,他引:1  
Efficient, sequential timing is essential for upper level pitching. Interestingly, pitchers vary considerably in timing related elements of pitching style including pelvis rotation, arm cocking, stride leg behaviour, and pitch delivery time. The purpose of this study was to determine whether relationships exist among these elements by examining the overall style of pitchers exhibiting different pelvis rotation patterns. Pitching styles were defined by pelvis orientation at the instant of stride foot contact. Pitchers demonstrating a pelvis orientation greater than 30 degrees were designated as 'early rotators', while pitchers demonstrating a pelvis orientation less than 30 degrees were designated as 'late rotators'. Kinematic and temporal differences were associated with the two styles. During the arm cocking phase, early rotators showed significantly greater shoulder external rotation at the instant of stride foot contact, earlier occurrence of maximum pelvis rotation angular velocity, and shorter time taken to complete the phase. However, by the instant of maximum shoulder external rotation, early and late rotators appeared remarkably similar as no significant difference occurred in pelvis and arm orientations. Therefore, it appears that early and late rotators used different methods to achieve similar results, including throwing velocity. Significant differences in throwing arm kinetics were also found for 10 of the 11 measures in the study. As the pelvis assumed a more open position at stride foot contact, maximum kinetic values were found to both decrease in magnitude and occur at an earlier time within the pitch.  相似文献   

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