Comparative analysis of selected biomechanic characteristics between a support backward swing and support swing for the 1 1/4 straddle-piked forward salto on the parallel bars

The aim of our research was to study the relationships between performance variables in a support backward swing (SBS), which was used as a progressive step in the learning procedure for a 1 1/4 straddle-piked front somersault and the swing prior to a 1 1/4 straddle-piked front somersault from support to bent arm support on the parallel bars (5/4S). Mitja Petkovsek, parallel bars gold medallist at the 2000 EC in Bremen, performed these elements. Kinematic analysis involved CMAS software (Praha, 1993), and the Suskana body segment model that has 17 points and 15 segments. Kinetic variables were estimated using 2D IMGIM software, which has 8 points and 6 segments (Colja and Cuk, 1994). The results indicated that some kinematic aspects of the two types of swings were similar but there were important differences in kinetic aspects of the motion. During the swing for the 5/4S, force and torque were higher than in the SBS.     

单杠“屈体前空翻一周半越杠再握”动作的运动生物力学分析

采用影片解析和生物力学分析法,对单杠“屈体前空翻一周半越杠再握”动作的振浪、撒手腾起、空中翻转及再握四个技术环节进行定量研究。     

双杠屈体后空翻两周成挂臂的技术特征及教法

以运动生物力学对双杠屈体后空翻（超E组的高难度动作）进行研究和技术分析，总结动作的技术规律和先进的教学方法。以此指导我国优秀运动员黄旭在短时间内高标准地掌握这一动作，于国内、外比赛获得成功。     

李娅高低杠反吊分腿前空翻再握杠的运动学分析

通过运动学分析揭示了李娅完成的高低杠反吊分腿前空翻再握杠的运动学规律和技术特点,为年轻运动员学习和改进此类动作提供理论依据和技术参考。     

双杠支撑摆动“钟摆式”保护方法探讨

运用常规保护法与“钟摆式”保护法等两种不同的方法，对双杠支撑摆动技术进行了研究和实践探索。实践表明：双杠支撑摆动的教学，教练员运用双手同时扶持运动员的躯干定点部位进行保护的方法(“钟摆式”保护法)，有助于运动员在短时间内掌握并提高双杠支撑摆动的技术。     

Whole-body and multi-joint kinematic control strategy variability during backward rotating dismounts from beam

The aim of this study was to develop insight into the whole-body and multi-joint kinematic control strategy variability associated with the execution of fundamental backward rotating dismounts from beam. Two-dimensional joint centre coordinate data were obtained for ten backward piked and backward tucked somersault dismount skills performed by four female gymnasts (N = 80 trials). Gymnast-specific and group variability in whole-body and multi-joint discrete kinematic measures were compared for the aerial and impact phase of backward piked and backward tucked skills. The backward tucked skill was executed using a more variable knee joint angular velocity at take-off (mean difference in standard deviation ± SD: -2.6 ± 1.0 rad · s(-1); P < 0.01) than the backward piked skill. The variability in the whole-body and multi-joint kinematic responses produced between the impact phases of each skill was gymnast-specific. The greater variability in the localized knee joint action at take-off was considered indicative of the diverse shape element demands and key performance outcomes of the two skills. Self-selected modulations to the multi-joint kinematic strategy used in the impact phase suggested customization of the joint loading adjustments in executing the fundamental dismount skills.     

世界蹦床运动动作现状及其发展

通过查阅相关资料和统计两次世界最高水平蹦床竞赛中使用的蹦床动作,确定了目前世界比赛中运动员所使用的动作情况。根据相关信息和对蹦床发展历史的回顾,分析了近期蹦床运动动作的发展形式。结果认为,蹦床预赛第1套动作中,主要采用1周空翻,男、女使用的1周空翻情况是相似的。非完整类空翻中,使用后空翻3/4周接腹弹的动作最多。蹦床预赛第2套动作和决赛套动作中,男子动作以2周高难度动作和3周动作为主体,以3周高难度动作为前沿动作。女子使用了12001o和12001<两个动作,其2周动作以2周空翻且转体在720°以下的难度动作为主。未来蹦床运动的发展趋势将促使运动员掌握更多的蹦床动作,比赛中对技术动作的评判将更加细致;在编排方面,预赛两套动作将结合更为紧密。     

Golf styles and centre of pressure patterns when using different golf clubs

Abstract

When using a driver, the centre of pressure of a golfer shows a pattern that is characteristic of one of two distinct swing styles: the “front foot” style or the “reverse” style. The aim of this study was to establish whether these two swing styles are also evident when using other clubs, and if so, to determine whether golfers use the same swing style when using different clubs. Forty-six professional, amateur, and recreational golfers performed swings to hit a ball into a net placed 3 m away. Ten swings were performed for each of the driver, 3-iron, and 7-iron while standing on two force plates. The position of the golfer's centre of pressure parallel with the line of shot and relative to the feet was quantified at eight swing events that were identified from 200-Hz video. Cluster analysis confirmed that the front foot and reverse styles were evident in all three clubs, and most of the golfers (96%) used the same swing style for all three clubs. Golfers that used the reverse swing positioned their centre of pressure nearer to their toes at ball contact compared with golfers that used the front foot swing.     

Understanding of Athletes' Nutritional Needs among Athletes,Coaches, and Athletic Trainers

Abstract

The electrogoniometer was used to study locomotion and some athletic movements. Motion patterns for the knee and ankle joint were established for walking and running on the horizontal and for walking up and downhill. Changing the inclination of the walking surface produced alterations of the knee and ankle goniograms which were consistent with body mechanics necessary to adjust to the respective grades. Knee and ankle goniograms are presented for the back handspring, front somersault, and back somersault. An electrogoniometer was waterproofed and used to obtain goniograms during the performance of three swimming strokes. Goniograms are also presented for throwing a baseball and putting the shot.     

体操运动中双杠悬垂前摆类动作技术的分类

根据文献资料,且结合当今体操比赛的实际,对双杠悬垂前摆类动作技术进行了分类,即前摆制动类、前摆腾空类,前摆转体类。在此基础上,对每一类动作技术的特点及发展趋势,进行了论述。     

Effect of Exertional Trend during Cycle Ergometry on Postexercise Affect

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.     

Selected Mechanical Factors Associated with Acceleration in Ice Skating

Abstract

The purpose of this study was to explore the techniques of ice skating acceleration through analysis of specific characteristics of the movement pattern during a “front start” skating task. Two Locam 16 mm cameras operating at 100 frames per second were used to record side and overhead views of the first 6.0m of the skating starts of 69 male subjects. Data were collected on three skating start criteria, three structural variables, and twelve performance variables measured over the first three strides of the start. Summary statistics were generated and Pearson product moment correlation analysis was used to assess relationships between the criteria and performance variables. In addition, stepwise multiple regression analysis was used to predict time to skate 6.0m from a combination of the structural and performance variables. Results revealed that the mean time taken to skate 6.0m was 1.95 sec; the mean instantaneous velocity at the 6.0 mark was 5.75 m/s; and the mean average acceleration over 6.0m was 2.96m/s². Evaluation of correlation coefficients, the regression model and summary statistics resulted in several conclusions: (1) There is a statistically significant positive relationship between velocity attained and the average rate of acceleration over a 6.0m distance in a front style skating start. (2) There are statistically significant negative relationships between both mean acceleration and final instantaneous velocity, and the time taken to skate 6.0m in a front style skating start. (3) In general, the stride pattern associated with a high rate of acceleration and a minimal skating time in a front style skating start includes: a high stride rate, significant forward lean at the point of touchdown of the recovery skate, short single support periods, and placement of the recovery foot below the hip of the recovery leg at the end of the single support period.     

Hip extension during the come-out of multiple forward and inward pike somersaulting dives is controlled by eccentric contraction of the hip flexors

Abstract

A modelling approach was used in the present study to investigate the role of the hip muscles during the come-out of forward and inward multiple somersaulting dives in a pike position. A planar two-segment model was used to simulate the somersault and come-out of three commonly performed dives from a 3-m springboard: forward two-and-one-half somersault pike dive (105B), forward three-and-one-half somersault pike dive (107B), and inward two-and-one-half somersault pike dive (405B). Three simulations were run for each dive: (1) hip angle was constrained to be constant, (2) hip torque was removed after 0.1 s, and (3) hip angle was constrained to a typical come-out time history used by elite divers. Simulation results indicated that hip flexion torque was required both to maintain a rigid pike position during somersault (range = 205.5–282.3 Nm) and to control the hip extension movement during the come-out (peak torque range = 355.8–548.1 Nm) in forward and inward multiple somersaulting dives. Coaches and divers should be aware that dry-land exercise drills producing hip extension movement by concentric actions of the hip extensor muscles do not replicate the neuromuscular control during the come-out of fast rotating dives.     

Golf styles and centre of pressure patterns when using different golf clubs

When using a driver, the centre of pressure of a golfer shows a pattern that is characteristic of one of two distinct swing styles: the "front foot" style or the "reverse" style. The aim of this study was to establish whether these two swing styles are also evident when using other clubs, and if so, to determine whether golfers use the same swing style when using different clubs. Forty-six professional, amateur, and recreational golfers performed swings to hit a ball into a net placed 3 m away. Ten swings were performed for each of the driver, 3-iron, and 7-iron while standing on two force plates. The position of the golfer's centre of pressure parallel with the line of shot and relative to the feet was quantified at eight swing events that were identified from 200-Hz video. Cluster analysis confirmed that the front foot and reverse styles were evident in all three clubs, and most of the golfers (96%) used the same swing style for all three clubs. Golfers that used the reverse swing positioned their centre of pressure nearer to their toes at ball contact compared with golfers that used the front foot swing.     

The biomechanics of twisting somersaults Part III: Aerial twist

A simulation model and a rigid body model are used to evaluate aerial twisting techniques. It is found that when somersault is not present, a number of cycles of segment counter‐rotation are required to produce one twist. When somersault is present, twist may be introduced by producing tilt using asymmetrical movements of the arms, chest or hips about the sagittal plane. The same asymmetrical movements may be used to remove tilt, although the effectiveness of these techniques is dependent upon body configuration and the direction of somersault.     

中学体操教学中双杠摆动手倒立技术与教学分析

在中学体操教学中,双杠摆动手倒立是个难度系数比较大的动作,掌握和运用这一动作技术要领,对于完成正确动作有很大的帮助。采用文献资料法、现场调查法,运用运动生物力学对该技术动作的要领进行了分析,并试图通过研究聊城市莘县一中中学体操的教学和训练,发现教学和训练中存在的问题,对体操教学中存在的各种常见问题如技术、心理、身体姿态等进行了探讨,并研究部分需要特别注意的技术环节,希望能为中学体操教学提供理论依据。     

体育院系体操普修双杠"短振屈伸上"动作的程序教学研究

通过教学实验,对程序教学方法和常规教学方法,在体育院系男子体操普修课双杠“短振屈伸上”技术课教学中的教学效果进行了比较研究。结果表明,程序教学方法能够提高学生的学习兴趣和学习积极性,在提高整体和不同层次学生成绩,以及降低学生学习后的遗忘率方面都优于常规教学方法。     

从涅莫夫雅典奥运会体操单杠飞行动作看振浪技术与肌肉用力感觉方法的训练

单杠正握向后大摆振浪动作是发展单杠高难度下法型、大回环型、空翻再握型和空翻越杠再握型的基础.文章对4种类型振浪技术动作中出现的9种肌肉用力感觉的方法,通过参考文献,经验的传授,进行归纳与总结,得出不同类型振浪技术动作中的各种肌肉用力感觉的方法,并对它们的相同之处与不同之处的重点部位找出有效的训练手段.     

中外优秀男子竞走运动员技术参数的对比分析

通过对一个竞走复步的分析，发现中外优秀男子运动员在后摆、前摆、前支撑、后支撑阶段中的运动学参数存在一定差异，找出我国运动员在技术方面存在的不足，为提高和完善我国男子运动员竞走技术提供理论支持。     

我国优秀蹦床运动员网上非技术性位移的初步研究

采用文献资料、现场观察、专家访谈、数理统计等研究方法 ,对我国高水平蹦床运动员网上水平位移现象进行初步研究。认为位移过大是影响成套动作稳定性及动作质量的重要因素之一 ;位移过大与起跳技术和连接技术不合理有关 ,也与运动员原有项目技能的负迁移影响有关 ;网上位移表现为一定的方向性 ,向前空翻类动作的水平位移略小于向后空翻类动作的位移。