Coordination as a function of skill level in the gymnastics longswing

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.     

The biomechanical design of a training aid for a backward handspring in gymnastics

This study was carried out to design, construct and assess a training aid to assist in the learning of a backward handspring. A backward handspring is often the first backward dynamic skill gymnasts will learn and so its performance can be accompanied by anxiety. International high performance coaches were surveyed to establish the key coaching requirements of a backward handspring training aid. A video analysis of the skill was used to determine characteristic dimensions of the skill, and these were used in the design of the training aid. The aid was designed and manufactured in accordance with European Standards for safety. The device’s safety for use in supporting the backward handspring was confirmed through testing. The assessment of the training aid using 11 gymnasts showed that it permitted a safe dynamic performance; provided support; did not obstruct technically good performances; allowed progressive use by novices without additional coach support; and was adjustable for gymnasts of various size and ability. When assessed against other training aids, it was the only aid that fulfilled all of the key coaching requirements.     

Circles with a suspended aid: reducing pommel reaction forces

The aim of this study was to investigate the influence of a suspended aid on the reaction forces during a basic skill on pommel horse. Twenty gymnasts performed three sets of 10 circles with and without a suspended aid on a pommel horse under which two force plates were set. The results confirmed that the suspended aid could reduce the magnitude of the pommel reaction forces during circles while maintaining the general loading pattern. On the left hand, the average and peak forces were attenuated to 0.59 body weight (BW) and 0.85 BW from 0.76 BW and 1.13 BW, respectively. The right hand experienced slightly larger forces with no-aid trials, but the asymmetry between the hands decreased with the aid. Despite a relatively large variability, all gymnasts experienced smaller impact peak forces with the aid. A suspended aid is most commonly used for a beginner gymnast as an introduction to pommel horse exercises. However, this study confirmed that it can also be useful for all levels of gymnasts who would like to practice pommel horse exercises with reduced pommel reaction forces for a purpose such as a progression for learning a new skill, control of training volume, or rehabilitation.     

Circles with a suspended aid: reducing pommel reaction forces

The aim of this study was to investigate the influence of a suspended aid on the reaction forces during a basic skill on pommel horse. Twenty gymnasts performed three sets of 10 circles with and without a suspended aid on a pommel horse under which two force plates were set. The results confirmed that the suspended aid could reduce the magnitude of the pommel reaction forces during circles while maintaining the general loading pattern. On the left hand, the average and peak forces were attenuated to 0.59 body weight (BW) and 0.85 BW from 0.76 BW and 1.13 BW, respectively. The right hand experienced slightly larger forces with no-aid trials, but the asymmetry between the hands decreased with the aid. Despite a relatively large variability, all gymnasts experienced smaller impact peak forces with the aid. A suspended aid is most commonly used for a beginner gymnast as an introduction to pommel horse exercises. However, this study confirmed that it can also be useful for all levels of gymnasts who would like to practice pommel horse exercises with reduced pommel reaction forces for a purpose such as a progression for learning a new skill, control of training volume, or rehabilitation.     

Musculoskeletal work preceding the outward and inward Tkachev on uneven bars in artistic gymnastics

Outward facing Tkachevs on uneven bars have been the traditional technique employed by artistic gymnasts. Changes in bar spacing and judging have increased the popularity of the inward version of the skill, in which the gymnast faces towards the low bar as she straddles over the high bar. The purpose of this study was to compare these two variants of the women's Tkachev to examine the influence of the positioning of the low bar on the musculoskeletal demands placed on the gymnast. 3-D DLT reconstructed data sets from digitised video images of straddle Tkachevs performed at the 2000 Sydney Olympics were analysed. Five performances of each variant were compared using kinematics and inverse dynamics. Mean hip and shoulder kinematics were similar for both variants of the Tkachev, but for the inward, gymnasts released later, travelled higher and re-grasped earlier than for the outward. Hip joint moments were similar for both variants while shoulder moments were different. Total musculoskeletal demands were similar for both variants, although the distribution was markedly different with the shoulders contributing positively for the outward and negatively for the inward. Implications for training specificity, along with potential future developments for the inward variant, have been highlighted.     

Biomechanical energetic analysis of technique during learning the longswing on the high bar

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.     

The influence of the vaulting table on the handspring front somersault

The traditional “horse” was replaced by a new vaulting “table” in artistic gymnastics competitions in 2001.The aim of this study was to determine whether the table led to a change in vaulting technique. This was achieved by comparing three-dimensional video-based analyses (50 Hz) of selected biomechanical discrete and continuous variables across four elite male gymnasts performing a series of handspring front somersault vaults on the traditional horse and the new table. Individual joint and inter-segment coupling (continuous relative phase) were used to quantify techniques used on the two apparatuses. Differences were attributed in part to the design and construction of the new table. No differences were observed for the approach and take-off from the board. Significant differences in hip flexion at board take-off and strike angle on the table were observed. One of the effects of the latter was an increase in vertical take-off velocity compared with the horse. Individual strategies were observed in hip and shoulder coordination patterns that were obscured when group data were considered. Close monitoring of the evolution of skill on this new apparatus is paramount for gymnastics coaching, and further studies of current elite competitive vaulting techniques are required.     

Skill level changes the coordination and variability of standing posture and movement in a pistol-aiming task

The study investigated the coordination and variability of posture and pistol motion for skilled pistol shooters and novices in a pistol-aiming task. The participants stood on a force platform and held a pistol with the preferred arm to aim for accuracy to a target on 30 s trials. The results revealed that the amount of the centre of pressure (COP) and pistol motion was lower for the expert than novice group. The time–varying structure of COP as indexed by multiscale entropy (MSE) and detrended fluctuation analysis (DFA) was also lower for the expert than the novice group. The relative phase between the COP in the anterior–posterior (AP) and pistol in the AP and between the COP in the medial–lateral (ML) and pistol in AP was close to inphase for the both groups. However, for the novice group the coordination patterns of posture and pistol motion were more variable with the pistol motion leading the posture motion while it was lagging in the skilled group. The findings show different qualitative and quantitative dynamics in pistol-aiming as a function of skill level with postural control foundational to supporting the reduced dispersion and complexity of the skilled arm-pistol motion.     

The Association between Physical Activity Behavior and Commonly Reported Barriers in a Worksite Population

Recent experiments on the ski simulator produced ambiguous results and raised unanswered questions concerning the true nature of “novice” behavior and the occurrence of behavioral changes during learning. The aim of the present experiment was to analyze the evolving behavior of three beginners during six practice sessions on a ski simulator. The position of the apparatus platform was recorded as time series and used for constructing dynamical models, including stiffness and damping functions. The results showed that novices tended to exploit a Rayleigh damping behavior during the first trials and then transition toward a van der Pol damping. These results replicate previous observations by Nourrit, Delignières, Caillou, Deschamps, and Lauriot (2003) and suggest the transition to the expert behavior could arise early in practice, when the task is of moderate difficulty. The discussion focuses on the properties of the observed learning dynamics and proposes a global conceptualization for acquiring complex motor skills.     

Learning from the experts: gaining insights into best practice during the acquisition of three novel motor skills

The amount and quality of practice predicts expertise, yet optimal conditions of practice have primarily been explored with novice learners. Ten expert musicians and ten novices practiced disc-throwing skills under self-regulated conditions. A third novice group practiced with the same schedule as the music experts (yoked). The groups did not differ in terms of the amount of contextual interference, only in terms of when in-practice interference was introduced. The music experts progressed from a more blocked to random schedule which was opposite to the novices. This resulted in more accurate performance in retention for the experts in comparison to both novice groups (self-scheduled and yoked). The music expert and yoked groups showed higher form scores than the novice self-scheduled group, which might be related to the greater frequency of augmented information for these groups. There was no evidence that non-task-domain experts choose a more random practice schedule than novices, but in accord with good practice principles, they gradually introduced high amounts of interference into their practice. This strategy was associated with less error in retention for the experts. Because the yoked group showed more error than the music experts, the advantage of this schedule was also performance dependent.     

Optimization of the felge on parallel bars

The felge, or undersomersault, on parallel bars has become an important skill in men's artistic gymnastics as it forms the basis of many complex variations. To receive no deductions from the judges, the felge must be performed without demonstrating the use of strength to achieve the final handstand position. Two male gymnasts each performed nine trials of the felge from handstand to handstand while data were recorded using an automatic motion capture system. The highest and lowest scoring trials of each gymnast, as determined by four international judges, were chosen for further analysis. The technique used by each gymnast was optimized using a computer simulation model so that the final handstand position could be achieved with straight arms. Two separate optimizations found different techniques identified in the coaching literature that are used by gymnasts. Optimum simulations resulted in improved performances through a combination of increased vertical velocity and height of the mass centre at release. Although the optimum technique found close to the gymnasts' own technique was more demanding in terms of the strength required, it offered the potential for more consistent performance and future developments in skill complexity.     

Changes in joint kinetics during learning the longswing on high bar

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.     

An analysis of practice activities and instructional behaviours used by youth soccer coaches during practice: Exploring the link between science and application

Abstract

We examined the practice activities and instructional behaviours employed by 25 youth soccer coaches during 70 different practice sessions. We evaluated the extent to which these activities and behaviours differ from those shown in contemporary research to best facilitate skill acquisition. Nine coaches worked with the under-9 years age group and eight coaches each with the under-13 and under-16 years age groups; nine of those coaches were employed at the elite level, nine at the sub-elite level, and seven at the non-elite level. Coaches had players spend more time in activities that were deemed less relevant to soccer match performance, termed “training form” (e.g. physical training, technique and skills practices), than activities deemed more relevant, termed “playing form” (e.g. small-sided/conditioned games and phase of play activities). Coaches provided high levels of instruction, feedback, and management, irrespective of the activity in which players engaged. Few differences in practice activities and instructional behaviours were reported across skill and age groups, implying the absence of any notable age- or skill-related progression. Findings are discussed with reference to recent research in the areas of skill acquisition, motor learning, and expert performance.     

男子体操山羊全旋挺胯侧伸技术的训练方法

通过多年的教学实验和潜心研究,对山羊全旋教学进行了许多训练方法上的尝试,并获得了比较满意的效果。研究结果表明：从运动员身体素质、年龄的差异分别引导,寻找全旋的节奏感觉,能较快的掌握侧伸挺胯技术的要领,经过一段时间的强化、系统的训练,全旋弧度可达到明显的效果。     

Consistency of performances in the Tkatchev release and re-grasp on high bar

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.     

Gaze Behavior of Gymnastics Judges: Where Do Experienced Judges and Gymnasts Look While Judging?

Gymnastics judges and former gymnasts have been shown to be quite accurate in detecting errors and accurately judging performance. Purpose: The purpose of the current study was to examine if this superior judging performance is reflected in judges’ gaze behavior. Method: Thirty-five judges were asked to judge 21 gymnasts who performed a skill on the vault in a video-based test. Classifying 1 sample on 2 different criteria, judging performance and gaze behavior were compared between judges with a higher license level and judges with a lower license level and between judges who were able to perform the skill (specific motor experience [SME]) and those who were not. Results: The results revealed better judging performance among judges with a higher license level compared with judges with a lower license level and more fixations on the gymnast during the whole skill and the landing phase, specifically on the head and arms of the gymnast. Specific motor experience did not result in any differences in judging performance; however, judges with SME showed similar gaze patterns to those of judges with a high license level, with 1 difference in their increased focus on the gymnasts’ feet. Conclusion: Superior judging performance seems to be reflected in a specific gaze behavior. This gaze behavior appears to partly stem from judges’ own sensorimotor experiences for this skill and reflects the gymnasts’ perspective onto the skill.     

对我国优秀艺术体操运动员心理技能特征的研究

本文对七运会艺术体操团体冠军贵州省（成都体院）艺术体操代表队的运动员心理技能特征进行了测试研究，为教练员科学地掌握本专项运动员的心理特点，建立优秀艺体运动员的选材模式、运动训练的控制及运动竞赛的成功，提供了研究方法和参考依据。     

Consistency of performances in the Tkatchev release and re-grasp on high bar

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.     

世界体操冠军程菲少儿时期训练特点

程菲已成为闻名世界的优秀体操运动员,她在武汉体育学院从事过两年多的初中级体操训练。实践证明,重视思想教育,关心队员学习与生活,扎实抓好全面的、基础的训练内容是培养优秀体操运动员的成功之路。程菲少儿时期的训练特点可为少儿体操运动员的基础训练提供有益的启示。     

论艺术体操运动员的智力因素和非智力因素

艺术体操运动员的成功不仅决定于她们的技战术 ,还决定于智力水平 ,而非智力因素对她们能否取得优异成绩也举足轻重。既提高艺术体操运动员的操作思维 ,同时又提高她们的语言思维能力是提高艺术体操运动员智力的明智之举 ;兴趣、意志、情感、动机、性格等是影响艺术体操走向成功之路最重要的非智力因素