A New Perspective on Motor Skill Automation

Abstract

The article by Richard A. Schmidt is directed to the locus of movement control. The paper's major goal is to describe a reconciliation between the peripheralists and the centralists. Schmidt describes major research issues for the future, along with current thinking about the central control of action in various theoretical conceptualizations of the structure of central motor programs. In the presentation on motor skill automation George E. Stelmach and Douglas D. Larish introduce the concept of attention and review research findings concerning attention, automation, and movement. They recommend automatic sequencing as a more viable theoretical position. Empirical support is given for the stance taken by these authors, followed by examples of potential approaches to research in motor behavior.     

Ecological correlates of sport and exercise participation among Thai adolescents: A hierarchical examination of a cross-sectional population survey

BackgroundUnderstanding factors influencing adolescents’ sport/exercise participation (S/EP) is vital to developing effective interventions, but currently, evidence from less developed countries is limited. The purpose of this study was to examine correlates of S/EP across individual, interpersonal, and environmental levels in a nationally representative sample of Thai adolescents.MethodsData from 4617 Thai adolescents aged 14–17 years old were obtained from recruited schools across Thailand. Data on S/EP (outcome variable), and psychosocial, home, and community environment covariates were collected from individual adolescents using the Thailand Physical Activity Children Survey, Student Questionnaire. School environmental data were collected at the school level using a School Built Environment Audit. Hierarchical regressions taking into account school clustering effects were applied for data analysis.ResultsAt the individual level, age and body mass index were independently and strongly correlated with S/EP. Adolescents with high preference for physical activity (PA) (odd ratio (OR) = 1.71, p < 0.001) and at least a moderate level of self-efficacy (OR = 1.33, p = 0.001) were more likely to have high S/EP. At the interpersonal level, adolescents whose parents joined their sports/exercise at least 1–2 times/week (OR = 1.36, p = 0.003) received ≥3 types of parental support (OR = 1.43, p = 0.005) and who received siblings’ (OR = 1.26, p = 0.004) and friends’ (OR = 1.99, p < 0.001) support had a greater chance of high S/EP. At the environmental level, adolescents’ S/EP was greater when there were at least 3–4 pieces of home sport/exercise equipment (OR = 2.77, p = 0.003), grass areas at school (OR = 1.56, p < 0.001), and at least 1–2 PA facilities in the community (OR = 1.30, p = 0.009).ConclusionMultiple factors at different levels within an ecological framework influencing Thai adolescents’ S/EP were generally similar to those found in developed countries, despite some differences. For those interested in promoting and supporting Thai adolescents’ engagement in sports/exercise, further exploration of the influence of self-efficacy and attitude toward PA is required at the individual level; parental and peer support at the interpersonal level; and home sport equipment, school grass areas, and neighborhood PA facilities at the environment level.     

The influence of pitch dimensions on performance during small-sided and conditioned soccer games

Abstract

This study examined the influence of pitch dimensions in small-sided soccer games in shaping opportunities for performers to maintain ball possession, pass to teammates and shoot at goal. Fifteen amateur standard male participants (M = 21.87, σ = 1.96 years) played 5 v 5 small-sided soccer games in three varying pitch conditions (28 m × 14 m, 40 m × 20 m and 52 m × 26 m). Thirty sequences of play in each condition were selected for digitisation using TACTO software, allowing the capture of bi-dimensional displacement coordinate data of all players and the ball. The values of interpersonal distance between all attackers and immediate defenders and the relative distances of defenders to intercept a shot and a pass were computed as dependent variables. Results showed existence of fewer opportunities to maintain ball possession on smaller pitches, compared to medium and larger pitches. Conversely, the different dimensions set to the pitch did not influence opportunities for players to shoot at goal, or to perform passes to other teammates. By examining the specific spatial–temporal relationships of players and key-task constraints, the data from this study explain how effects of manipulating pitch dimensions of small-sided games might enhance opportunities for acquiring specific movement and decision-making skills.     

Gymnastics

Abstract

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#fr1/4> straddle‐piked front somersault and the swing prior to a 1#fr1/4> straddle‐piked front somersault from support to bent arm support on the parallel bars (5/4S). Mitja Petkov?ek, 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 ?uk, 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.     

Factor Analysis of Selected Basketball Skill Tests

Abstract

The purpose of this study was to investigate the factor structure of the sports skill domain of basketball and to identify test items to measure in this skill domain. A theoretical model of the hypothesized dimensions of basketball playing ability was developed based on a review of literature concerning basketball skill testing from 1906 to the present day. These dimensions were: (a) shooting, (b) passing, (c) jumping, (d) movement without the ball and (e) movement with the ball. Twenty-one items, including the nine items in the AAHPER basketball skill test for boys, were selected to sample these hypothesized dimensions. The tests were administered to 70 male junior high and high school students enrolled in the University of Minnesota, Duluth basketball camp during the summer of 1975. The hypothesized dimensions were analyzed by use of the following: (a) alpha factor analysis; (b) canonical factor analysis; (c) image analysis; and (d) principal components analysis. Both oblique and orthogonal rotations were performed with each of the four analyses. The hypothesized model was partially substantiated in that the results confirmed three of the factors: (a) shooting, (b) passing and (c) jumping with the only difference being that the factors of movement with the ball and movement without the ball combined into one. Since the following test items best represented the dimensions, it appeared that a battery comprised of these items would provide a quick and objective measure of basketball skill: (a) jump and reach, (b) dribble, (c) speed pass, and (d) front shot.     

对我国优秀女子铁饼选手最后用力技术的运动学分析

掷铁饼技术的最后用力是整个技术过程的关键环节。采用高速同步摄影与影片三妥析的方法,对我国部分优秀女子铁饼选手的投掷技术进行测试,取得所需技术参数原始数据,运用解析的最后用力技术单腿支撑和双腿支撑阶段时间、人体与器械质心速度变化,以及器械质心高、低点出现时机等多种技术参数,揭示掷铁饼最后用力技术中人体－器械系统的运动学特征,并提出相关结论和建议,为教学、训练和科学提供定量化参考依据。     

梁琼高低杠反吊屈体分腿前空翻450°越杠再握的运动学分析

梁琼高低杠反吊屈体分腿前空翻450°越杠再握动作是我国首创"莫氏空翻"之后的又一 次重要的创新。研究中,较完整地提供了该动作各技术阶段的运动学参数并进行了分析。结果显 示,该项技术具有"晚顶伸"、"晚鞭打"、"早撒手"等特点。同时指出,跟肩速度不快,导致再握杠 时肩角、髋角过小,身体重心离杠轴太近,是影响该动作的主要问题。     

Bodies,Meanings and Movement: A Comparison of the Language of a Physical Education Lesson and a Feldenkrais Movement Class

In Western societies since (and probably before) Descartes, the human body has been objectified and alienated from the self, something to be subdued, managed and more recently worked upon as symbol of self-value. Sport and exercise are sites where the objectification of the body has been traditionally promoted. In recent times with the scientisation of elite sport and the commodification of bodies in sport, the objectification of the body has taken new forms and achieved greater prominence. Physical education as the school site for body work has been implicated in the process of objectification and alienation. The traditional practices of physical education, including choices in teacher language, position bodies as objects, and movement as an instrumental outcome of practice. Not all movement practices, however, subscribe to this approach. This paper will compare the language practices of teachers in a physical education lesson and a Feldenkrais movement class as these constitute different forms of embodiment, different selves. Its purpose is to provide further resources for critical reflection on the ways in which pedagogical practices position students and contribute to the shaping of particular forms of subjectivity.     

Effects of Movement Context on the Encoding of Kinesthetic Spatial Information

Abstract

Effects of movement context upon the encoding of kinesthetic spatial location information were examined in a series of experiments using a motor learning paradigm. A cross-modal, kinesthetic to kinesthetic plus visual feedback procedure was used in each experiment to determine the encoding characteristics of spatial information within a variety of movement conditions. Following knowledge of results trials, subjects performing in cross-modal conditions had significant directional errors (overshooting of the target) for spatial locations associated with specific and non-specific body-referents (Experiment 1), for different movement directions to the same target (Experiment 2), and for long (40 cm) movements (Experiments 2, 3) and short (15 cm) movements (Experiment 4). However, subjects in both intermodal and intramodal conditions who switched movement direction had significant undershooting of the spatial targets (Experiment 3). Movement context in terms of response endpoint location or movement length did not have an apparent effect on directional errors. Performances in all experimental conditions were biased in the direction of the movement during learning. The context provided by movement direction did influence the encoding of kinesthetic spatial information.     

金光淑高低杠特卡切夫接肖空翻技术的运动生物力学分析

本文通过对朝鲜女运动员金光淑在北京亚运会高低杠比赛中完成的特卡切夫接肖空翻动作的运动生物力学分析,结果发现:(1)在振浪下沉过程中,身体总重心最快速度在杠下垂面以前,这从理论上对传统的最快速度在杠下垂直面的观点提出了新的见解;(2)在特卡切夫类动作的制动动作过程中,通过振臂压腿,使踝关节速度降到最低点,形成以脚为中心的瞬时转动中心时,能获得最佳的反向旋转,为腾越后的再握创造了有利条件。     

Examination of the Validity of the Social Support Survey Using Confirmatory Factor Analysis

Abstract

The Social Support Survey (SSS), validated by Richman, Rosenfeld, and Hardy (1993), is a multidimensional self-report measure of social support tested with student athletes. The SSS contains eight dimensions of support. For each dimension of support the same four questions are posed. The SSS could, therefore, be scored in two ways: (a) to derive a score for the support dimensions; (b) to derive a score for the questions posed across all eight support dimensions. Confirmatory factor analyses of the SSS on 416 university athletes revealed poor fits to models for both the eight support dimensions and the four questions across all eight dimensions. This problem was clarified by using a multitrait-multimethod model, which led to improved model fit but revealed that most of the SSS items were two-dimensional. Caution should, therefore, be exercised in using the SSS as a measure of multidimensional social support.     

高低杠支撑后摆分腿屈体经手倒立转体180°动作的技术特点与教法

运用生物学及教学观察等方法,探讨了高低杠支撑后摆分腿屈体经手倒立转体180°动作的技术特点,并提出了掌握该技术动作的教学训练方法。     

Calculating upper limb inertial parameters

Abstract

In the kinematic and kinetic analysis of human movement, an accurate assessment of the inertial properties of the body segments under investigation is often essential. Statistical and geometric models of the segments of the upper limb were examined to determine their ability to predict the moments of inertia of these segments. The cadaver data of Chandler et al. (1975) were used as the criteria with which computed values were compared. The regression equations of Hinrichs (1985) gave the most accurate results; the geometric models appeared to offer the greatest flexibility.     

北京奥运周期世界男子双杠比赛特点的研究

以北京奥运周期三次世界大赛男子双杠决赛运动员成套动作为研究对象,对世界双杠比赛特点进行研究.结果表明:成套动作的平均A分从39届世锦赛的6.427分迅速升至北京奥运会的6.888分,最高达到7.1分,选手之间的差距越来越小,继续提高动作难度的空间较小;成套动作的结构仍以支撑摆动组为主,悬垂大摆和短半径回环动作迅速增长,两组接近占总数的1/2;挂臂摆动组动作数量逐渐减少,下法类型有多元化发展的趋势;今后应在既定动作难度基础上,努力提高完成动作的质量.     

Effects of age,maturity and body dimensions on match running performance in highly trained under-15 soccer players

Abstract

The aim of the present study was to compare, in 36 highly trained under-15 soccer players, the respective effects of age, maturity and body dimensions on match running performance. Maximal sprinting (MSS) and aerobic speeds were estimated. Match running performance was analysed with GPS (GPSport, 1 Hz) during 19 international friendly games (n = 115 player-files). Total distance and distance covered >16 km h^–1 (D > 16 km h^?1) were collected. Players advanced in age and/or maturation, or having larger body dimensions presented greater locomotor (Cohen’s d for MSS: 0.5–1.0, likely to almost certain) and match running performances (D > 16 km h^?1: 0.2–0.5, possibly to likely) than their younger, less mature and/or smaller teammates. These age-, maturation- and body size-related differences were of larger magnitude for field test measures versus match running performance. Compared with age and body size (unclear to likely), maturation (likely to almost certainly for all match variables) had the greatest impact on match running performance. The magnitude of the relationships between age, maturation and body dimensions and match running performance were position-dependent. Within a single age-group in the present player sample, maturation had a substantial impact on match running performance, especially in attacking players. Coaches may need to consider players’ maturity status when assessing their on-field playing performance.     

伦敦奥运周期我国女子高低杠技术水平现状研究

运用文献资料、录像观察、数理统计等方法,对我国2010-2012年3次国内比赛高低杠决赛前8名选手以及30届伦敦奥运会高低杠决赛前8名选手所完成的成套动作进行研究。剖析伦敦奥运周期我国女子高低杠技术水平现状：上法以＂跳上高杠—屈伸上＂动作为主流;下法以＂团身后空翻两周转体360°下＂和＂直体后空翻两周下＂动作为主流;＂帕克空翻＂成为中国队员高换低动作的＂规定动作＂;＂低杠蹬杠弧形换握至高杠＂仍是我国队员低换高的主流动作,成为被裁判严格扣分的＂软肋＂;编排连接串以＂三连接＂为主流,其中又以＂林转—凌转—分腿叶格尔＂为主流连接,成套动作的连接价值与世界水平相比整体偏低;我国队员整体D分低于世界水平,而动作的完成质量则差距更大。建议中国女队尽快发展D组以上的低杠换握高杠动作,努力发展＂回环转体—飞行＂的二连接动作,提高＂大摆回环＂和＂近杠回环＂转体成倒立以及＂屈伸上—后摆成倒立＂的动作质量,尽快提高我国高低杠的整体竞技水平。     

Comparative analysis of sequentiality using SDIS-GSEQ and THEME: A concrete example in soccer

Abstract

Within an observational design aimed at studying what type of soccer is better adapted to the possibilities of the 11–12 year-old child, a comparison was made of the results obtained using two fully consolidated analysis techniques in observational methods, and which form the basis in the development of two respective software programs: SDIS-GSEQ and THEME, which allow one to detect the existence of sequential patterns hidden in a data set. This work is intended to shed light on the comparison of results obtained using these two analysis techniques. In particular, the data used for the analysis are multicode event data (using the lexicon of the sequential analysis), and do not incorporate the duration parameter. Accordingly, for the detection of regular structures using the THEME program (T-patterns), a constant duration has conventionally been assigned to each occurrence. Using THEME, among the greatest number of sequential structures detected, diachronic and synchronic correspondence was observed (T-patterns reflecting identical multi-events) with each and every one of the sequential patterns obtained using the lag technique, by the SDIS-GSEQ software. This coincidence strengthens the link between the algorithms that support SDIS-GSEQ and THEME. The results indicate that 7-a-side soccer and 9-a-side soccer types facilitate the spatial mastery of the game by the child, compared with the adult form, 11-a-side soccer.     

确定下肢肌肉附着点空间坐标的研究及其应用

采用近景摄影测量的先进技术,对人体(尸体)下肢肌肉的起止点进行量测;运用计算机进行编程解析,求得国人下肢肌肉附着点的三维坐标。建立下肢4个运动环节的独立坐标系;运用刚体方位广义坐标描述下肢环节运动;提供肌肉机能评定相关的定量参数资料。建立起止点坐标与有关的人体测量参数间的回归方程,为活体下肢肌肉起止点的推算提供依据。     

Relationship between the Perception and Reproduction of Body Postures

Abstract

One hundred and seven college women were tested in their ability to recognize a demonstrated body posture from among similar ones and to reproduce demonstrated body postures. Two original tests were devised for this purpose. A low but statistically significant correlation (- .34) was found between the two. In addition, the subjects completed a questionnaire regarding the extent and nature of their motor experience. The extent of the individual's motor experience had a significant role in each of these abilities. The direction to be taken in reproducing the postures was found to be a complicating factor.     

Interactions among Dietary Pattern,Physical Activity and Skinfold Thickness

Abstract

This study was designed to assess the effects of a specifically designed perceptual-motor training program on the level of perceptual-motor development, self-concept, and academic ability of kindergarten children. Subjects for the study were 40 kindergarten children randomly assigned to 1 of 2 groups. Each group received the same kindergarten program with one exception, the experimental group was exposed to a specifically designed perceptual-motor program 30 min daily for 5 mo, while the control group received a free play period for 30 min daily. Results of the study indicated that the data tended to support the specificity of training concept. The variables showing the greatest change were the perceptual-motor tests which measured changes on specific aspects of the training program. There appeared to be some immediate transfer to academic abilities but this was not pronounced enough to suggest that perceptual-motor training was of real benefit in developing academic abilities for normal kindergarten children. In addition the follow-up test indicated no long term effects on academic performance.