The quantification of joint laxity in dancers and gymnasts.

The aim of this study was to determine the range of movement in gymnastic and dance populations. Sixty-five participants (41 females, 24 males; mean age 21.4 years) were assessed. The sample included dancers and gymnasts ranging from novice and club standard to international and professional status. Non-specialized physical education students acted as controls. Range of movement was measured at the shoulders, hips, lumbar spine and ankles using a Loebl hydrogoniometer, and inherent joint laxity was assessed using Beighton and coworkers' adaptation of the Carter and Wilkinson 9-point scale. The right and left sides of the body were assessed and measures of active and passive motion were recorded. A graded increase in laxity was observed from controls, through novice gymnasts, to dancers and finally international gymnasts. The greater laxity of females than males was also confirmed. Dancers and gymnasts had a greater passive range of movement in all joints, which was partly inherited and partly acquired. There was a large difference between their active and passive ranges, which appeared to render the joints unstable.     

Foot and ankle joint movements of dancers and non-dancers: a comparative study

Ballerinas use their ankle joints more extremely and sustain injuries on the ankle joint more frequently than non-dancers. Therefore, the ankle movement of dancers is important and should be studied to prevent injuries. Measuring ankle joint range of motion (ROM) using radiographs could demonstrate the contribution to motion of each joint. The aim of this study was to analyse and compare ankle joint movements and the ratio of each joint’s contribution during movement between dancers and non-dancers, using radiographic images. Dancers have lower dorsiflexion (26.7 ± 6.2°), higher plantarflexion (74.3 ± 7.1°) and higher total (101.1 ± 10.8°) ROMs than non-dancers (33.9 ± 7.0°, 57.2 ± 6.8° and 91.1 ± 9.3°, respectively) (p < 0.05). Although the ROMs were different between the two groups, the ratios of each joint movement were similar between these two groups, in all movements. Regarding total movement, the movement ratio of the talocrural joint was almost 70% and other joints accounted for almost 30% of the movement role in both dancers and non-dancers. Therefore, the differences in ROM between dancers and non-dancers were not a result of a specific joint movement but of all the relevant joints’ collaborative movement.     

Sleep,training load and performance in elite female gymnasts

Training load (TL) and recovery should be in optimal balance to obtain maximal performance gains. We aimed to study sleep as a recovery technique and its relationship with TL and performance in elite athletes. Twenty-six elite female artistic gymnasts were divided into an under 13 (n?=?6), an under 14 (n?=?6), a junior (n?=?7; 14–15y) and a senior (=World Championship (WC) competitors, n?=?7; ≥16y) category. Sleep, through sleep logs, and training parameters, using the session Rate of Perceived Exertion (sRPE) scale, were monitored to calculate total sleep time (TST), sleep efficiency (SE), TL, monotony and strain. Performance of WC competitors was evaluated through coach and WC qualification ranking. For the entire group, TST (effect sizes (ES)?=??1.12, confidence intervals (CI)?=??60:?47, P?P?=?.022) were shorter during week than weekend nights. TST and SE were highest in youngest gymnasts (P?P?P?P?P?=?.030). TST correlated with coach ranking (r?=??0.857, P?=?.014). Higher TL correlated with worse WC (r?=?0.829, P?=?.042) and coach (r?=?0.893, P?=?.007) ranking. This research in elite gymnasts indicated associations between decreased TST, augmented TL and inferior performance. Optimizing sleep and TL may therefore represent strategies to enhance performance.     

运动员在不同运动特征中人格差异性研究综述

本文运用文献资料法和逻辑分析法,对在不同项目、不同运动等级以及不同性别中的运动员人格差异性进行研究综述,旨在为今后运动员的选材与训练提供参考。     

Effect of verbal instructions and image size on visual search strategies in basketball free throw shooting

We assessed the effects on basketball free throw performance of two types of verbal directions with an external attentional focus. Novices ( n = 16) were pre-tested on free throw performance and assigned to two groups of similar ability ( n = 8 in each). Both groups received verbal instructions with an external focus on either movement dynamics (movement form) or movement effects (e.g. ball trajectory relative to basket). The participants also observed a skilled model performing the task on either a small or large screen monitor, to ascertain the effects of visual presentation mode on task performance. After observation of six videotaped trials, all participants were given a post-test. Visual search patterns were monitored during observation and cross-referenced with performance on the pre- and post-test. Group effects were noted for verbal instructions and image size on visual search strategies and free throw performance. The 'movement effects' group saw a significant improvement in outcome scores between the pre-test and post-test. These results supported evidence that this group spent more viewing time on information outside the body than the 'movement dynamics' group. Image size affected both groups equally with more fixations of shorter duration when viewing the small screen. The results support the benefits of instructions when observing a model with an external focus on movement effects, not dynamics.     

我国女子体操运动员踝关节损伤的原因及对策

调查分析九运会女子体操预赛132名运动员的运动损伤情况，结果显示：踝关节损伤是最主要的损伤(占65％)，其原因有技术、生理、训练多重因素。分析认为，应重视蹦床弹网训练，发展下肢力量并根据少年女子生理特点进行训练。     

Technique selection in young female gymnasts: Elbow and wrist joint loading during the cartwheel and round-off

Biophysical loading of the elbow and wrist is a potential reason for chronic lesions in gymnastics and present a real concern for coaches, scientist and clinicians. Previous research has identified injury risk factors during round-off (RO) skills in elite female gymnasts. The aim of this study was to investigate key elbow and wrist joint injury risk factors during different techniques of fundamental cartwheel (CW) and RO skills performed by young female artistic gymnasts. Seventeen active young female gymnasts performed 30 successful trials of both CW and RO from a hurdle step with three different hand positions (parallel (10), T-shape (10) and reverse (10)). Synchronised kinematic (240?Hz) and kinetic (1200?Hz) data were collected for each trial. One-way repeated measures ANOVA and effect size (ES) were used for statistical analysis. The results showed statistically significant differences (P?0.8) among hand positions for peak vertical ground reaction force (VGRF), peak elbow compression force, peak wrist compression force, elbow internal adduction moment and wrist dorsiflexion angle. In conclusion, the parallel and reverse techniques increase peak VGRF, elbow and wrist compression forces, and elbow internal adduction moment. These differences indicate that the parallel and reverse techniques may increase the potential of elbow and wrist injuries in young gymnasts compared with the T-shape technique; this is of particular importance with the high frequency of the performance of these fundamental skills.     

A comparison of knee joint laxity among male and female collegiate soccer players and non-athletes

Female athletes are at least twice as likely to sustain an anterior cruciate ligament injury than male athletes. The underlying cause of ACL injury is multifactorial. However, several researchers have identified knee joint laxity as a possible contributing factor. The purpose of this study was to provide a comparison of knee joint laxity between male and female collegiate soccer players and male and female non-athletes. Thirty-nine (19 male, 20 female) apparently healthy, collegiate athletes from the University of Texas at El Paso's 2001-2002 women's intercollegiate soccer team and men's club soccer team, and forty (20 male, 20 female) non-athletic students volunteered to participate. All participants were tested bilaterally using the KT-1000 MEDmetric knee joint ligament arthrometer. Three tests were used to determine anterior laxity: passive displacement, active displacement, and the Lachman test. The mean passive displacement, mean active displacement, and Lachman (only for the left leg) were significantly lower for the athletic group than for the non-athletic group. There were no significant differences found between males and females for the passive and active drawer tests. However, females had significantly more laxity than males in the Lachman test. These findings suggest that strength and conditioning may play a more significant role in knee joint laxity than the sex of the individual.     

山西省7个地市青少年女运动员头发中6种微量元素的地区性差异研究

本文采用电感偶合等离子光谱法(ICP/AES),对山西省7个地市(大同、忻州、太原、榆次、临汾、离石和运城)体校的青少年女运动员头发中的6种元素(Ca、Fe、Zn、Cu、K、Mg)进行了对比分析,结果表明:(1)头发是一种可用来检测机体元素水平的理想材料(回收率:92.03％-103.35％;％RSD<3.08)。(2)在7个地市中,除Zn元素之外的5种元素含量都存在有地域性差异(P<0.05)。(3)分析结果提示应增力。青少年女运动员膳食中Fe、Cu、Zn的含量,其中又以Cu、Zn为主。(4)人体是一个复杂的有机体,身体中的元素变化不仅与基础膳食和生理状况有关,而且还与人文地理环境有着密切的相关关系。     

论提升优秀游泳运动员运动寿命的策略

随着体育全球化的推进,各种体育赛事层出不穷。游泳是奥运会的重要比赛项目,奖牌多,影响力大。新形势下,世界泳坛百花争艳,各国选手都极具竞争力,而我国游冰运动员的运动寿命短暂,平均年龄低于国外选手,忽视了许多大器晚成的优秀运动员。因此,本文通过介绍“运动寿命”的定义,分析我国优秀游泳运动员的培养现状,讨论造成优秀游泳运动员运动寿命短暂的因素,寻找延长优秀游泳运动员运动寿命的策略。     

The measurement of competitive anxiety during balance beam performance in gymnasts

Abstract

The purpose of the present study was to investigate competitive anxiety during balance beam performance in gymnasts. Competitive anxiety was assessed continuously by heart rate monitoring and by retrospective self-report of nervousness in eight female national level gymnasts during their balance beam routine during one competition and two training sessions. A significant negative correlation was found between the score of the retrospective self-report of nervousness and performance during the routine. There were no significant differences in performance score by the judges between the three test sessions. There were also no differences in the retrospective self-report of nervousness. However, heart rate was significantly higher during the competition session than during the training sessions. The potential value of the retrospective report of nervousness for the study of critical events during gymnastic performance is illustrated. The results are discussed in the light of catastrophe theory.     

The measurement of competitive anxiety during balance beam performance in gymnasts

The purpose of the present study was to investigate competitive anxiety during balance beam performance in gymnasts. Competitive anxiety was assessed continuously by heart rate monitoring and by retrospective self-report of nervousness in eight female national level gymnasts during their balance beam routine during one competition and two training sessions. A significant negative correlation was found between the score of the retrospective self-report of nervousness and performance during the routine. There were no significant differences in performance score by the judges between the three test sessions. There were also no differences in the retrospective self-report of nervousness. However, heart rate was significantly higher during the competition session than during the training sessions. The potential value of the retrospective report of nervousness for the study of critical events during gymnastic performance is illustrated. The results are discussed in the light of catastrophe theory.     

Acute and residual effects of vibratory stimulation on explosive strength in elite and amateur athletes

Fourteen elite and 14 amateur athletes were subjected to vibratory stimulation during bilateral biceps curl exercises of explosive strength exertion. The athletes performed two separate series of three sets of exercises in random order. The second set of one series was administered with superimposed vibration of 44 Hz and an acceleration of about 30 m .s-2 transmitted through the two-arms handle to the arm muscles. The mechanical power of each repetition was measured by the ‘Power Teach’ instrument. The maximal and mean power values for each set were automatically recorded and shown on the screen. The acute effect was evaluated as the difference between the mean and peak power output in the second (with vibratory stimulation) and first (without vibratory stimulation) sets. Similarly, the residual effect was taken to be the difference between the power values of the third (after vibratory stimulation) and the first (before vibratory stimulation) sets. The results were subjected to a repeated-measures analysis of variance with group as a between-participants factor. The results showed that exercise mode (with vs without vibratory stimulation) resulted in a significant immediate effect for mean power and for maximal power. The factor group (elite vs amateurs) resulted in a significant effect for maximal power only. The increase in explosive strength exertion attributed to vibratory stimulation was 30.1 and 29.8 W (10.4% and 10.2%) for maximal and mean power respectively in the elite group, and 20.0 and 25.9 W (7.9% and 10.7%) respectively in the amateur athletes. Vibratory stimulation resulted in an insignificant residual effect.     

Sex differences in elbow and wrist joint loading during the cartwheel and round off with different hand positions performed by young gymnasts

The aim of the study was to determine if sex differences exist in the key elbow and wrist joint injury risk factors during different cartwheel (CW) and round-off (RO) techniques performed by young male and female artistic gymnasts. Sixteen active young gymnasts (8 males and 8 females) performed 30 successful trials of CW and RO with three different hand positions (parallel (10), T-shape (10) and reverse (10)). Synchronised kinematic and kinetic data were collected for each trial. Two-way repeated measures ANOVA (3 × 2, technique × sex) and effect-sizes (ES) were used for statistical analysis. In conclusion, female gymnasts exhibited greater normalised peak vertical ground reaction forces (VGRF), elbow and wrist compression forces and elbow internal adduction moments during CW and RO skills compared with male gymnasts. In both sexes, the parallel and reverse techniques increased peak VGRF, elbow and wrist compression forces and the elbow internal adduction moment. Increased elbow flexion resulted in decreased peak VGRF, elbow compression forces and elbow internal adduction moment. Injury risk factors including elbow extension and internal adduction moment with axial compression force suggest that a CW and RO in reverse and parallel techniques can be hazardous especially for young female gymnasts.     

我国体育舞蹈选手性格特征研究

采用文献资料法、专家访谈法、问卷调查法及数理统计法,从心理学角度探讨我国体育舞蹈选手的性别、年龄、舞种及训练水平与不同的性格结构的差异,从而总结出体育舞蹈选手的性格特征发展的一般规律.     

运动员选材智能评价系统的研究与设计

对传统运动选材法进行分析的基础上，结合人工神经网络的自学习特点，集成管理信息系统（MIS）和决策支持系统（DSS）的理论成果，在选材工作人员帮助下，设计并开发出运动员选材智能评价系统，该系统具有界面交互友好，功能强大等特点，是进行选材决策的有益助手。     

The measurement of shoulder alignment in cricket fast bowling

The aim of this study was to compare thoracic spine alignment with two-and three-dimensional calculations of shoulder alignment (defined as a line joining the acromion processes of the right and left scapula) when all measures were projected onto the transverse plane. A six-camera Vicon system was used to reconstruct three markers positioned on the plane of the thorax such that the orthogonal vector to the thoracic spine, projected onto the transverse plane, was used as a virtual shoulder alignment during cricket fast bowling. This same measurement system was used to calculate the three-dimensional line between the acromion processes projected onto the transverse plane. These acromion markers were also used to calculate the two-dimensional transverse plane alignment of the shoulders from images recorded by a video camera positioned above ball release. All cameras operated at 50 Hz. A significant association was recorded between thorax alignment and the three- (0.97) and two-dimensional (0.87) shoulder alignment estimations at back-foot impact. The strength of association remained at front-foot impact, when correlations of 0.89 (three-dimensional) and 0.84 (twodimensional) were recorded. However, at ball release, non-significant associations of 0.58 (three-dimensional) and 0.41 (two-dimensional), representing shoulder alignment differences of approximately 10°, were recorded. The 95% limits of agreement comparisons for shoulder alignment at back-foot impact, front-foot impact and ball release produced mean random errors for the two comparisons of 9.5°, 11.7° and 22.5° respectively. Three- and two-dimensional transverse plane projections of shoulder alignment are reasonable estimates of thorax alignment at back-foot impact and front-foot impact but not at ball release.     

散打运动员在比赛中不良心理现象及其调控

文章采用观察法、访谈法,并运用运动心理学的相关知识,简要分析散打运动员比赛中的几种不良心理现象及产生原因,并制订了一些克服不良心理现象的方法,为基层教练员对运动员心理训练提供一些可供参考的方法和依据。     

动作记忆规律对动作技术学习的影响--以再现法为研究范式

研究尝试从基础理论层面着手,以动作记忆为切入点,通过再现法来探究动作操作的记忆进程以及动作操作的记忆特点,为运动技能的学习提供心理方面的理论支持,进一步为体育教学内容改革提供理论依据。     

The value of a non-sport-specific motor test battery in predicting performance in young female gymnasts

Gymnastics talent identification focuses on the identification of young gymnasts who display characteristics for potential success in the future. The aim of this study was to identify which current performance characteristics are related to performance in competition 2 years later. Twenty-three female gymnasts aged 7-8 years completed a multidimensional test battery measuring anthropometric, physical, and coordinative characteristics and were technically evaluated by expert coaches. Two years later, the all-around competition results of those gymnasts now participating in elite (n = 12) and sub-elite (n = 11) competition were obtained. None of the initial measurements significantly correlated with the results of the sub-elite gymnasts 2 years later. For the elite gymnasts, a non-sport-specific motor test battery correlated strongly with the competition result, with more than 40% of the variation in competition performance being explained by the result on that test 2 years earlier. Neither the coaches' judgement nor the anthropometric and physical characteristics were sensitive enough to predict performance. A motor coordination test might be valuable in the early identification of gymnasts, as its discriminative and predictive qualities might be sufficiently powerful for selection within a relatively homogeneous population of gymnasts exhibiting similar anthropometric and physical profiles.