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1.
The purpose of this study is to provide evidence of technique changes during learning a sports-specific skill, the looped bar longswing (LLS). Thirteen male participants with no previous high bar experience took part in a training study. Kinematic data were collected using a CODA motion analysis system (200 Hz) during eight weekly testing sessions. Analyses focused on the amplitude of swing and the functional phase (FP) actions, defined by the rapid flexion to extension of the shoulders and extension to flexion of the hips as the performer passed through the lower vertical. Three groups were identified based on the number of sessions it took each participant to perform the LLS (G1: most successful, G2: intermediate, and G3: least successful). All participants were able to significantly increase swing amplitude over the training period (p < 0.05). For each participant the hip FP started significantly: later for G1, earlier for G2, and did not change for G3. Extension actions at the shoulders were dissimilar to those reported for elite gymnasts performing the longswing. The FP of the hips provides a mechanism to distinguish between the learners of different skill levels. The study has provided support for a single-subject design when investigating technique changes during learning.  相似文献   

2.
Biomechanics helps us understand the association between technique changes and performance improvement during learning. The aim of this research was to investigate joint kinetic characteristics of technique during learning of the longswing on the high bar. Twelve male, novice participants took part in the learning study. During swing attempts in 8 weekly testing sessions, kinematic data were collected. Inverse dynamics analysis was performed from known zero forces at the toes to quantify joint moments and power at the hips and shoulders. Key biomechanical constraints that limited performance outcome were identified based on changes in joint kinetics during learning. These constraints were the ability to perform a large shoulder power and to overcome passive kinetics acting during the downswing. Constraints to action at the level of joint kinetics differentially challenge learners and therefore could underpin more individual, specific learning interventions. Functional phases, defined by maximum hyperextension to flexion of the hips and maximum flexion to extension of the shoulders, did not describe the key joint kinetics of the hip and shoulder for novices. The functional phases may serve however to identify novices that were unable to overcome the passive kinetic constraint.  相似文献   

3.
Kinetic analyses of the chalked bar longswing on high bar and its associated progressions were used to explain musculoskeletal contributions during the performance of these skills. Data on four international male gymnasts performing three series of chalked bar longswings and eight progressions were recorded. Customized body segment inertia parameters, two-dimensional kinematics (50 Hz), and bar forces (1000 Hz) were used as input to inverse dynamic modelling. The analysis focused on the relative contributions of the knees, hips, and shoulders with root mean squared differences between the chalked bar longswing and the progressions being used to rank the progressions. Seventy per cent of the total work occurred between 200 degrees and 240 degrees of angular rotation in the longswing, 67% of which was contributed by the shoulders. The shoulders were also dominant in all progressions, with the largest such contribution occurring in the looped bar longswing with "no action". The least similar progression was the looped bar pendulum swing, while the most similar was the chalked bar bent knee longswing. This study provides a useful means for ranking progressions based on their kinetic similarity to the chalked bar longswing and builds on earlier research in identifying that progressions can be classified into those similar in physical demand (kinetics) and those similar in geometry (kinematics).  相似文献   

4.
Kinetic analyses of the chalked bar longswing on high bar and its associated progressions were used to explain musculoskeletal contributions during the performance of these skills. Data on four international male gymnasts performing three series of chalked bar longswings and eight progressions were recorded. Customized body segment inertia parameters, two-dimensional kinematics (50 Hz), and bar forces (1000 Hz) were used as input to inverse dynamic modelling. The analysis focused on the relative contributions of the knees, hips, and shoulders with root mean squared differences between the chalked bar longswing and the progressions being used to rank the progressions. Seventy per cent of the total work occurred between 200° and 240° of angular rotation in the longswing, 67% of which was contributed by the shoulders. The shoulders were also dominant in all progressions, with the largest such contribution occurring in the looped bar longswing with “no action”. The least similar progression was the looped bar pendulum swing, while the most similar was the chalked bar bent knee longswing. This study provides a useful means for ranking progressions based on their kinetic similarity to the chalked bar longswing and builds on earlier research in identifying that progressions can be classified into those similar in physical demand (kinetics) and those similar in geometry (kinematics).  相似文献   

5.

Purpose: Improvements in motor performance and coordination may be impacted by the interaction of practice and organismic constraints. It has been proposed that these aspects of motor learning are achieved at a different time rate: first, during placement of the events (performance), and second, segmental spatiotemporal relationships (coordination). We focused on the acquisition of the longswing in high bar as one basic skill in gymnastics. The aim of this study was to determine how longswing performance and coordination change to increase swing amplitude as age and expertise increase. Method: One hundred and thirteen male gymnasts were classified into 5 distinct age groups (G1, G2, G3, G4, and G5) on the basis of the national competition rules. Longswing performance (swing amplitude and event placements) and coordination (positive and negative areas in the continuous relative phase) were measured for each group. Results: Analyses of variance revealed that the adequate placement and coordination of the earlier events were achieved in younger groups (G1, G2), while later events and their coordination were accomplished by the older groups (G3 through G5). Conclusion: Our results suggested that the process of longswing acquisition, as age and expertise increase, follows a progression parallel to the temporal occurrence of the task events, instead of the proposed learning sequence of event placement first and then coordination.  相似文献   

6.
The Tkatchev on the high bar is a release and re-grasp skill in which the gymnast rotates in a direction during flight opposite to that of the preceding swing. Since the release window is defined as the time during which the gymnast has appropriate linear and angular momentum to ensure the bar can be re-grasped, it was speculated that the release windows for this skill would be smaller than for dismounts that are less constrained. One senior male gymnast competing at national standard performed 60 Tkatchev trials. A four-segment planar simulation model of the gymnast and high bar was used to determine the release windows in 10 successful and 10 unsuccessful performances of the Tkatchev recorded using a Vicon motion analysis system. Model parameters were optimized to obtain a close match between simulations and recorded performances in terms of rotation angle (1 degree), bar displacements (0.01 m), and release velocities (1%). Each matched simulation was used to determine the time window around the actual point of release for which the model had appropriate release parameters to complete the Tkatchev successfully. The release windows for the successful trials were small compared with those of dismounts. The unsuccessful trials were associated with later release and later timing of the actions at the shoulders and hips.  相似文献   

7.
This study focused on identifying the most effective skill progression for developing the longswing on high bar in men's artistic gymnastics. Building on previous work by Irwin and Kerwin, in which a method to rank progressions based on their angular kinematics was developed, this study aimed to use the method to quantify similarities in inter-segmental coordination between selected progressions and the longswing on high bar. Video images of four members of the UK men's national gymnastics squad performing three series of five longswings and eight progressions were recorded at 50Hz. Two-dimensional direct linear transformation techniques were used to determine the real-world coordinates from the digitized data. Inter-segmental coordination of the hip and shoulder joints during the functional phases of the longswing was assessed using continuous relative phase. Similarity between the longswing and each progression was represented by a "specificity score", which was also used to rank the progressions. Each progression's specificity score was calculated by combining a "difference score" (root mean squared difference between the continuous relative phase profiles of the longswing and the progression) and a "variability score" (standard deviation of the continuous relative phase profiles for each progression). The progressions that were most similar to the longswing included the looped bar longswing and layaway swing down (ranked 1st and 2nd), with specificity scores of 9% and 10% respectively. In contrast, the least similar progressions were the looped bar "no action" longswing (51%) and pendulum swing (63%) (ranked 7th and 8th). Establishing effective skill learning pathways is recognized as a key component of the coaching process and ranking progressions based on their specificity score provided a mechanism to identify progressions with similar inter-segmental coordination profiles to the key skill on the high bar, the longswing.  相似文献   

8.
The Tkatchev on the high bar is a release and re-grasp skill in which the gymnast rotates in a direction during flight opposite to that of the preceding swing. Since the release window is defined as the time during which the gymnast has appropriate linear and angular momentum to ensure the bar can be re-grasped, it was speculated that the release windows for this skill would be smaller than for dismounts that are less constrained. One senior male gymnast competing at national standard performed 60 Tkatchev trials. A four-segment planar simulation model of the gymnast and high bar was used to determine the release windows in 10 successful and 10 unsuccessful performances of the Tkatchev recorded using a Vicon motion analysis system. Model parameters were optimized to obtain a close match between simulations and recorded performances in terms of rotation angle (1°), bar displacements (0.01 m), and release velocities (1%). Each matched simulation was used to determine the time window around the actual point of release for which the model had appropriate release parameters to complete the Tkatchev successfully. The release windows for the successful trials were small compared with those of dismounts. The unsuccessful trials were associated with later release and later timing of the actions at the shoulders and hips.  相似文献   

9.
Based on specificity of training and biomechanical analysis, the aim of this study was to develop a method to rank selected progressions for learning the longswing on high bar. Four members of the Men's National Gymnastics Squad were recorded (50 Hz) performing three series of five longswings and eight progressions. Real world co-ordinates from the digitized data were determined using two-dimensional direct linear transformation. Biomechanical similarity between the functional phases of the longswing and the corresponding phases of the progressions were calculated. The functional phases were described as a hyperextension to flexion of the hip and hyperflexion to extension of the shoulder joints as the gymnast passed underneath the bar. Using a combined score of 'Difference' and movement 'Variability' a 'Specificity score' was calculated for hip and shoulder angular displacements and velocities. An overall score based on the average of the four scores provided a ranked list of progressions based on their similarity to the target skill. The progression that showed the greatest similarity to the biomechanics of the longswing, and was therefore ranked first, was the chalked bar pendulum swing. The least similar progression, and, therefore, eighth ranked, was the chalked bar bent knee longswing. The hip kinematics were found to contribute most to the overall differences because the performance requirements of these progressions emphasize an increase in hip flexion during the ascending phase. The method described provides a means to quantify and rank progressions based on their kinematic similarity to the longswing.  相似文献   

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.
Understanding the technical requirements and underlying biomechanics of complex release and re-grasp skills on high bar allows coaches and scientists to develop safe and effective training programmes. The aim of this study was to examine the differences in the functional phases between the Tkatchev and Kovacs skills and to explain how the angular momentum demands are addressed. Images of 18 gymnasts performing 10 Tkatchevs and 8 Kovacs at the Olympic Games were recorded (50 Hz), digitised and reconstructed (3D Direct Linear Transformation). Orientation of the functional phase action, defined by the rapid flexion to extension of the shoulders and extension to flexion of the hips as the performer passed through the lower vertical, along with shoulder and hip angular kinematics, angular momentum and key release parameters (body angle, mass centre velocity and angular momentum about the mass centre and bar) were compared between skills. Expected differences in the release parameters of angle, angular momentum and velocity were observed and the specific mechanical requirement of each skill were highlighted. Whilst there were no differences in joint kinematics, hip and shoulder functional phase were significantly earlier in the circle for the Tkatchev. These findings highlight the importance of the orientation of the functional phase in the preceding giant swing and provide coaches with further understanding of the critical timing in this key phase.  相似文献   

12.
The purpose of this study was to investigate the nature of inter-joint coordination at different levels of skilled performance to: (1) distinguish learners who were successful versus unsuccessful in terms of their task performance; (2) investigate the pathways of change during the learning of a new coordination pattern and (3) examine how the learner’s coordination patterns relate to those of experts in the longswing gymnastics skill. Continuous relative phase of hip and shoulder joint motions was examined for longswings performed by two groups of novices, successful (n = 4) and unsuccessful (n = 4) over five practice sessions, and two expert gymnasts. Principal component analysis showed that during longswing positions where least continuous relative phase variability occurred for expert gymnasts, high variability distinguished the successful from the unsuccessful novice group. Continuous relative phase profiles of successful novices became more out-of-phase over practice and less similar to the closely in-phase coupling of the expert gymnasts. Collectively, the findings support the proposition that at the level in inter-joint coordination a technique emerges that facilitates successful performance but is not more like an expert’s movement coordination. This finding questions the appropriateness of inferring development towards a “gold champion” movement coordination.  相似文献   

13.
ABSTRACT

When learning swinging skills on a bar there has been conflicting advice in the research literature regarding whether to coach the “gold standard” technique to novices. The present study aimed to determine how technique (joint angle time histories) and (inter-limb) coordination changed as novice gymnasts learned a fundamental gymnastics skill (the upstart). It was hypothesised that both technique and coordination would become more like an expert as learning progressed. Eight novice gymnasts, unable to perform an upstart, underwent four months of training, with the number of successful upstarts out of 10 recorded at the start and then every month subsequently. In the first and last sessions motion capture was used to determine joint kinematics. Root mean squared differences for the joint angle time histories and continuous relative phase at the shoulder and hip were calculated between the novices and an expert gymnast. As training progressed technique and coordination became more like the expert gymnast. The more successful novices were better able to time their actions within the swing than the less successful novices. Gymnastics coaches teach towards a “gold standard” technique since being successful at the skill is not the only goal, as considerations for future skill development are made.  相似文献   

14.
An individual's a priori talent can affect movement performance during learning. Also, task requirements and motor-perceptual factors are critical to the learning process. This study describes changes in high bar swing performance after a 2-month practice period. Twenty-five novice participants were divided by a priori talent level (spontaneous-talented [ST] and nonspontaneous-talented [NST]) and compared to experienced gymnasts. Additionally, we assessed their perception of their performance level before and after practice. We defined three events independently for hip (H) and shoulder (S) angle joints and for the lag between consecutive events (phases [P]): the smallest angle during downswing (P1H, P1S), the largest angle after P1 (P2H, P2S), and the smaller angle during upswing (P3H, P3S). Movement performance variables were the maximum elevation on the downswing (Pi) and the upswing (Pf), and the total path between both (swing amplitude). Data were collected during pre- and postpractice sessions by two video cameras. At the end of both sessions, participants drew a sketch to represent their perception of their performance level relative to the Pi, Pf and the hip events. Results showed a similar practice effect in the swing amplitude in both novice groups. However the ST group 's performance and perception variables on the downswing improved more than the NST group due to practice. This study suggests that (a) downswing improvements were easier than in the upswing, possibly due to familiarity of the visual reference in combination with proprioceptive feedback; and (b) being ST may involve a better orfaster gain in perception of self-action compared to NST.  相似文献   

15.
Tkachev on uneven bars is a release and re-grasp skill performed using variations of preparatory longswing techniques; the reasons why different techniques are chosen remains unclear. This study examined kinematic and key release parameters specific to three distinct techniques with the aim of understanding the relative benefits of each. During two international artistic gymnastics competitions six arch, straddle and pike longswings preceding the straddle Tkachev were recorded using twin video cameras. Calibration and movement images were digitised and reconstructed using 3D DLT. Shoulder and hip angular kinematics, angular momentum and key release parameters were compared between techniques. In the arch longswing, the first and second hip functional phases began significantly earlier than the straddle or pike. No significant differences were established for release parameters although large effect sizes for horizontal release velocity and angular momenta about the mass centre and bar were reported between the arch and other two variants. Therefore, the arch variant may provide the opportunity to develop more complex combinations following the Tkachev. Providing insight into mechanical advantages of specific longswing techniques, and highlighting those that elicit desirable characteristics offers the potential to provide coaches with objective data on technique selection and ultimately skill development.  相似文献   

16.
Most previous research on golf swing mechanics has focused on the driver club. The aim of this study was to identify the kinematic factors that contribute to greater hitting distance when using the 5 iron club. Three-dimensional marker coordinate data were collected (250 Hz) to calculate joint kinematics at eight key swing events, while a swing analyser measured club swing and ball launch characteristics. Thirty male participants were assigned to one of two groups, based on their ball launch speed (high: 52.9 ± 2.1 m · s(-1); low: 39.9 ± 5.2 m · s(-1)). Statistical analyses were used to identify variables that differed significantly between the two groups. Results showed significant differences were evident between the two groups for club face impact point and a number of joint angles and angular velocities, with greater shoulder flexion and less left shoulder internal rotation in the backswing, greater extension angular velocity in both shoulders at early downswing, greater left shoulder adduction angular velocity at ball contact, greater hip joint movement and X Factor angle during the downswing, and greater left elbow extension early in the downswing appearing to contribute to greater hitting distance with the 5 iron club.  相似文献   

17.
Tkachev on uneven bars is a release and re-grasp skill performed using variations of preparatory longswing techniques; the reasons why different techniques are chosen remains unclear. This study examined kinematic and key release parameters specific to three distinct techniques with the aim of understanding the relative benefits of each. During two international artistic gymnastics competitions six arch, straddle and pike longswings preceding the straddle Tkachev were recorded using twin video cameras. Calibration and movement images were digitised and reconstructed using 3D DLT. Shoulder and hip angular kinematics, angular momentum and key release parameters were compared between techniques. In the arch longswing, the first and second hip functional phases began significantly earlier than the straddle or pike. No significant differences were established for release parameters although large effect sizes for horizontal release velocity and angular momenta about the mass centre and bar were reported between the arch and other two variants. Therefore, the arch variant may provide the opportunity to develop more complex combinations following the Tkachev. Providing insight into mechanical advantages of specific longswing techniques, and highlighting those that elicit desirable characteristics offers the potential to provide coaches with objective data on technique selection and ultimately skill development.  相似文献   

18.
肖春梅 《中国体育科技》2012,48(3):100-103,128
目的:研究不同平衡训练方法对提高老年人抗摔倒平衡能力影响.方法:通过对36名分为单项平衡训练组(ST)、固定双重任务训练组(FP)和不定双重任务训练组(VP)健康老年人(70.65±5.48岁),进行为期8周、每周3次、每次45min的不同方法的平衡训练.在训练前、后分别进行BBS、TUG、ABC、SOT、LOS指标测试,进行统计分析讨论.结果:在CDP标准测试条件下SOT、BBS、ABC测试,3组训练后都有显著提高,P＜0.05,FP、VP组比单项任务组明显高,FP组P＜0.05、VP组P＜0.001.LOS测试,3个对照组测试结果无统计学显著性差异.TUG测试,3组训练后都有显著降低,P＜0.05,FP、VP组比单项任务组明显降低,FP组P＜0.05、VP组P＜0.001.VP组比FP组测试指标表现出更好的平衡功能.结论:单项任务的平衡训练可以使老年人在双重任务条件下的表现部分提高,而双重任务条件下的平衡训练表现能更好地优化老年人在双重任务条件下的稳定性.VP条件下双重任务训练,注意力同时分配在认识与平衡任务上,是最佳化提高老年人平衡功能、防摔倒的训练方法.  相似文献   

19.
Abstract

Male volunteers (N=80) were randomly assigned to either a control or a mental practice group for the learning of three motor skills, the hock swing to a horizontal bar, jump-foot, and soccer hitch kick. All subjects were tested individually on each of the skills but one group engaged in five directed mental practice sessions spaced over a period of 5 days prior to being tested. Significant differences between groups in initial trial success were obtained for the hock swing but not for the other two skills. After physical practice was introduced, the mental practice group required fewer trials to achieve success in the hock swing and the jump-foot but not in the soccer hitch kick. It was concluded that the effectiveness of mental practice without prior physical practice is specific to the skill and is more pronounced for simpler skills.  相似文献   

20.
高低杠脱手再握类动作撒手技术研究   总被引：2，自引：2，他引：0  
运用摄像解析和数理统计的方法,对高低杠的叶格尔、特卡切夫、京格尔三种类型动作及其繁衍动作的技术特征进行分析。结果显示：肩、髋角缩小（向前为增大）,兜（鞭）腿动作的快速有力,适度留肩动作是上摆的共性特征;制动阶段特卡切夫类和叶格尔类动作的技术特征是髋角变化幅度大,重心远离杠水平,制振明显;撒手瞬时三种类型动作的特征为重心远离握点且位置有高有低,肩角顶开幅度有大有小;人体腾空后获得与回环方向相反翻转角速度大小不同。  相似文献   

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