Peripheral vision and simple catching: The screen paradigm revisted

The importance of effector visual feedback has previously been indicated using an opaque screen to prevent sight of the catching hand for the final 150–200 ms of a flight path of 850 ms in total. Attention was drawn to the finding that the ability to position the arm correctly in the line of flight of the ball deteriorated as a consequence of the number of trials without visual feedback. However, the use of only 20 test trials allows a possibility that the proprioceptive system may be able to re‐establish predominant control under conditions of prolonged visual decrement. In order to verify this notion, the number of experimental trials was quadrupled for 24 subjects of mixed sex in a replication of the initial paradigm.

The results provided preliminary support for the view that the positioning of the catching arm is more seriously affected by visual occlusion than the timing of the grasp phase. However, increments in accuracy of limb orientation were evidenced in all screen conditions, as the number of trials increased. The grasp component of one‐handed catching appeared to remain unaffected by the increase in experimental trials. The relative influence of skill level on catching errors was next addressed by comparing the performance of the six best and worst catchers in the group.

The results did not support previous research which found a relation between skill level and error type. The number of position, but not grasp, errors decreased as a function of task practice for both subgroups. Future investigations should, perhaps, focus on the developmental nature of movement control in one‐handed catching to obtain a clearer picture of this relation.     

Influence of a baseball glove on the nature of errors produced in simple one-hand catching

The influence of a baseball glove on the positioning and grasping components of one-hand catching was studied under both vision impaired and unimpaired conditions. Skilled softball and baseball players (N = 20) caught tennis balls barehand and softballs with a fielder's glove. In half of the trials, a screen positioned alongside the subject's head blocked vision of the catching hand. All trials were videotaped and errors were categorized by type (position or grasp). Results indicated that with the glove performance was essentially perfect, regardless of the screen condition. Barehand grasping performance, however, was affected by the subject's inability to see his hand to a much greater extent than barehand positioning. We argue that the baseball glove functions to reduce both the positioning accuracy requirements and the grasp timing requirements in simple catching. Peripheral vision of the limb, however, is necessary for controlling the barehand grasp phase.     

Laterality differences in elite ice hockey: an investigation of shooting and catching orientations

Little is known about the implications of motor asymmetries for skilled performers in dynamic, time-constrained, team-based activities such as ice hockey. Three studies were conducted to examine laterality differences in ice hockey. Study 1 investigated laterality distributions across three leagues of increasing calibre. Among skating players, skill level was related to changes in laterality patterns based on position, while a significant increase in the proportion of left-catching goaltenders was found across the levels of competition. Study 2 examined laterality differences through a 90-year retrospective analysis of player performance measures within an evolving system. Regression analysis indicated right shot preferences were associated with scoring more goals, while left shot preferences were related to assisting more goals. Among goaltenders, right-catching preferences were associated with an increased save percentage compared with left-catching goaltenders. In Study 3, player-goaltender shootout interactions revealed left shooters to be less successful against right-catching goaltenders. Results suggest ice hockey supports models of skilled perception, and provide new information in the area of laterality and strategic frequency-dependent effects in ice hockey.     

Tackling femininity: the heterosexual paradigm and women's soccer in South Africa

Sport is a social institution that perpetuates gendered ideologies in the wider society through appealing to discourses of the naturalness of men's privilege and domination in society. Heteronormativity regulates the roles, behaviours, appearances and sexualities of, and relationships between and among, women and men. Moreover, heteronormative discourses normalise a particular relationship between sex, gender and sexuality that posits woman/feminine/heterosexual (and man/masculine/heterosexual) as a natural order from which variance is considered a punishable deviance. This paper outlines the effects of heteronormative discourses in the lives of women footballers in South Africa, through drawing on interviews with a wide range of women footballers. The paper shows how heteronormative discourses nurture homophobic attitudes that serve to regulate the appearances and performances of South African women.     

Quiet eye training aids the long-term learning of throwing and catching in children: Preliminary evidence for a predictive control strategy

Abstract

Quiet eye training (QET) may be a more effective method for teaching children to catch than traditional training (TT) methods, but it is unclear if the benefits accrued persist in the long term. Thirty children were randomly allocated into a QET or TT group and, while wearing a mobile eye tracker, underwent baseline testing, training and two retention tests over a period of eight weeks, using a validated throw and catch task. During training, movement-related information was provided to both groups, while the QET group received additional instruction to increase the duration of their targeting fixation (QE1) on the wall prior to the throw, and pursuit tracking (QE2) period on the ball prior to catching. In both immediate (R1) and delayed (R2, six weeks later) retention tests, the QET group had a significantly longer QE1 duration and an earlier and longer QE2 duration, compared to the TT group, who revealed no improvements. A performance advantage was also found for the QET compared to the TT group at both R1 and R2, revealing the relatively robust nature of the visuomotor alterations. Regression analyses suggested that only the duration of QE1 predicted variance in catch success post-training, pointing to the importance of a pre-programming visuomotor strategy for successful throw and catch performance.     

Gender equality in the Olympic Movement: not a simple question,not a simple answer

This article explores the strategies followed by the International Olympic Committee for the achievement of gender equality. It is argued that this international body can go beyond simply adopting an equality of opportunities approach to gender equality. It suggests which other strategies can be incorporated for which it draws on the different ways of understanding gender equality in gender political theory.     

Estimation of the energy loss at the blades in rowing: Common assumptions revisited

Abstract

In rowing, power is inevitably lost as kinetic energy is imparted to the water during push-off with the blades. Power loss is estimated from reconstructed blade kinetics and kinematics. Traditionally, it is assumed that the oar is completely rigid and that force acts strictly perpendicular to the blade. The aim of the present study was to evaluate how reconstructed blade kinematics, kinetics, and average power loss are affected by these assumptions. A calibration experiment with instrumented oars and oarlocks was performed to establish relations between measured signals and oar deformation and blade force. Next, an on-water experiment was performed with a single female world-class rower rowing at constant racing pace in an instrumented scull. Blade kinematics, kinetics, and power loss under different assumptions (rigid versus deformable oars; absence or presence of a blade force component parallel to the oar) were reconstructed. Estimated power losses at the blades are 18% higher when parallel blade force is incorporated. Incorporating oar deformation affects reconstructed blade kinematics and instantaneous power loss, but has no effect on estimation of power losses at the blades. Assumptions on oar deformation and blade force direction have implications for the reconstructed blade kinetics and kinematics. Neglecting parallel blade forces leads to a substantial underestimation of power losses at the blades.     

Teacher versus peer models revisited: effects on motor performance and self-efficacy

This study reinvestigated and extended the findings of Landers and Landers (1973), which examined the influence of skilled and unskilled teacher and peer models on motor performance. Sixth grade females (N = 100) were randomly assigned to groups in a 2 x 2 (Model Type x Model Skill) factorial design or to a no-model group. In the treatment groups, subjects observed one of four unfamiliar models--(a) a skilled teacher, (b) an unskilled teacher, (c) a skilled peer, or (d) an unskilled peer--perform on the Bachman ladder task. Subjects performed 30 trials of the task and also completed self-efficacy questionnaires on three occasions. Results showed that subjects who watched a skilled model performed better than subjects who watched an unskilled model. Unlike the Landers and Landers study, no model type by model skill interaction was found. In addition, the skilled model group reported higher efficacy beliefs than the control group after performing and were more efficacious than the unskilled model subjects both after watching the model and after performing. These results suggest when students view unfamiliar models, the skill rather than the status of the model may be more salient.     

对“功能动作训练”之“功能动作筛查”的审视与思考

作为一种全新训练理念的代表——功能动作训练正逐渐被我国专家学者及教练员所接受.所谓“功能动作训练”是在对人体基本动作模式进行测试、诊断和纠正的基础上,采用某些特殊设计的动作练习手段,以最大限度地规避运动损伤风险,提高动作效率,促进运动水平提高的动作方法体系的总和.其核心内容包括功能动作筛查、伤病预防和动作准备等8个部分.作为整个功能动作训练体系的奠基石,功能动作筛查的重要性是不言而喻的.分别从原理、作用、操作、排序及纠正方法5个方面对功能动作筛查理论进行系统的研究,以期为后续研究功能动作训练体系其他方面的内容奠定基础.     

Sports vision training: A review of the state-of-the-art in digital training techniques

Athletes need excellent vision to perform well in their sports, and many athletes have turned to vision training programs as a way to augment their traditional training regimen. The growing practice of ‘sports vision training’ relies on the notion that practice with demanding visual perceptual, cognitive, or oculomotor tasks can improve the ability to process and respond to what is seen, thereby improving sport performance. This enterprise is not necessarily new, but has been advanced greatly in the past few years by new digital technology that can be deployed during natural training activities, by perceptual-learning-inspired training programs, and by virtual reality simulations that can recreate and augment sporting contexts to promote certain sports-specific visual and cognitive abilities. These improved abilities may, in turn, instill a competitive advantage on the playing field, underscoring the potential value of these approaches. This article reviews emerging approaches, technologies and trends in sports vision training. Where available, critical review of supporting research is provided.     

Factor structure,stability, and congruence in the functional movement screen

The scoring scheme for the functional movement screen implicitly assumes that the factor structure is consistent, stable, and congruent across different populations. To determine if this is the case, we compared principal components analyses of three samples: a healthy, general population (n = 100), a group of varsity athletes (n = 101), and a group of firefighters (n = 397). The congruence of the principal components derived through these analyses were evaluated across all of the samples, using Tucker’s congruence coefficient. Factor extraction was guided by parallel analyses, and interpretation was facilitated by Varimax rotation. We observed factor instability, low factor congruence, and inconsistent factor structure. Additionally, we observed a two-factor structure of the functional movement screen in all of our sample groups. These analyses suggest that, although the independent elements of the functional movement screen may continue to be used, use of the composite score is not supported by the factor structure of the measure.     

Teachers as agents of change in curricular reform: the position of dance revisited

This paper reports findings from a recent large-scale survey of Physical Education (PE) teachers’ perceptions of teaching dance and compares them to results of a study completed 10 years previously [MacLean, J. (2007). A longitudinal study to ascertain the factors that impact on the confidence of undergraduate physical education student teachers to teach dance in Scottish schools. European Physical Education Review, 13(1), 99–116]. The current position of dance is examined in light of the introduction of Curriculum for Excellence (CfE) in 2010, a national initiative in Scottish schools that provides a unified flexible curricular framework for children aged 3–18. Dance remains part of the PE curriculum but also for the first time in Scotland occupies an additional position within the Expressive Arts (EA). Teachers are positioned as agents of change tasked with greater autonomy, flexibility and responsibility in curriculum design. The inclusion of dance in both PE and EA provides potential for teachers to design curricula that excludes dance from the PE curriculum or alternatively use the opportunity to increase dance provision. Currently, little is known about the impact CfE has on the provision and position of dance or the factors that impinge on teachers’ decisions regarding the inclusion of dance in the curriculum. To further such understanding, 85 secondary school PE teachers responded to a questionnaire concerning dance opportunities within the current school context. In addition, the original participants from MacLean (2007) research were re-interviewed to identify and explore the factors that enable teachers to achieve agency when teaching dance. The results indicated that collaborative planning, united goals and collective action had enabled teachers to significantly increase dance provision in schools. Teacher attention had shifted from concerns about individual capacity to a focus on the level of social, cultural and material support in providing valuable educational experiences in dance for all pupils.     

Age-related differences in vision and proprioception in a lower limb interceptive task: the effects of skill level and practice

This study examined age-related differences in the role of visual proprioception during a lower limb interceptive action and how this varies as a function of skill and practice. In Experiment 1, skilled and less-skilled 8-, 10-, and 12-year-old boys controlled a soccer ball using their preferred foot under full vision and when sight of the effector was occluded. With the exception of the high-skilled 12-year-olds and low-skilled 8-year-olds, participants showed a decrement in peformance when denied access to visual proprioception. In Experiment 2, the effect of practicing under different informational constraints was examined for 12 year-old boys. Children performed varying amounts of practice under full vision, or in a condition where sight of the foot was occluded, before being transferred to the alternative viewing condition. Participants who practiced under occluded viewing conditions showed greater relative improvement in performance over practice and transfer sessions compared with a full vision control group. Some support is provided for the manipulation of visual informational constraints as an effective pedagogical approach to motor learning.     

Information source utilization and teachers' attributes in physical education: a preliminary test of a rational paradigm

This study sought to provide empirical evidence concerning physical education information-seeking patterns of elementary teachers at the primary level. It also investigated the relationship between information use patterns and teachers' attributes. A model based on simple utilitarian concepts explaining information use patterns was developed and tested. The basic assumption of the model was that the use of information sources would increase as the perceived benefits of the information derived increased, and the costs of retrieving and using the information decreased. Subjects for the study were elementary school teachers from the Vancouver school system in British Columbia, Canada (N = 86). Simultaneous equation procedures employing limited information likelihood estimators were used to test the model. The results of the study indicated that sources of information internal to the school system dominated utilization patterns. Among these, curriculum support material and discussion with colleagues were highly favored, suggesting that teachers at these grade levels rely heavily upon the experience of others in the same system and the support of very specific resource materials about physical education activities. The research also showed that those who felt they knew more and claimed to enjoy teaching actively sought to acquire more knowledge from more sources than those who knew less. Finally, the study demonstrated that models based on simple assumptions of rationality can predict decisions concerning information utilization.     

The association between environmental and psychosocial factors towards physical activity and screen time of children: an application of the Integrative Behavioural Model

Physical activity is beneficial at all stages of life, and has been linked as a protective factor from obesity, and other chronic health conditions. Despite the benefits of physical activity, less than half of US children meet the current recommendations, and activity levels decline with age. When planning physical activity interventions, behavioural theories should be utilised, given the inherent benefits theory-based approaches possess. The purpose of this study was to investigate how constructs of the Integrative Theoretical Model (IM) are associated with physical activity and screen time among children (9 years ±1.2; n = 264). Using structural equation modeling, a final model proved to have a good fit (CFI = 0.989; TLI = 0.975; RMSEA = 0.043), and results indicated intentions and perceived behavioural control (PBC) explained 19.4% of the variance for physical activity, and attitudes, perceived norms, and PBC accounted for 62% of the variance of intentions. Furthermore, attitudes and perceived norms were negatively associated with total screen time, and accounted for 10% of the variance. Results suggest that IM is a useful framework for explaining physical activity and screen time among children.     

场域视野下高校图书馆发展社会学分析——以北京体育大学图书馆为例

运用文献资料、专家访谈和逻辑分析等方法,以布迪厄场域理论为基础,以北京体育大学为例,对高校图书馆场域中行动者的资本和惯习等进行了详细分析。通过研究,得出以下结论,高校图书馆管理者的权力资本在高校图书馆场域中占据支配地位,管理者和工作人员技能资本的不足使高校图书馆的服务质量有待提升,作为经济资本持有者之一的大学生在师道尊严的惯习下知识学习和技能习得诉求未得到很好的满足。因此,高校图书馆要从弱化图书馆管理者的权力资本、构建新型的师生关系、提高图书馆管理者和工作人员的技能资本、激发大学生主观能动性的发挥等几个方面促进图书馆的建设与发展,真正体现“读者第一、服务至上”的图书馆管理理念,从而使高校图书馆真正成为学生知识学习、技能掌握、科研创新的第二课堂。     

Out with the old,in with the new: how changes in cricket helmet regulations affect the vision of batters

The International Cricket Council recently introduced new regulations for helmets in cricket. Amongst other changes, these regulations limit batters from adjusting the gap between the peak and the grille, resulting in some controversy over whether the new helmet design reduces visibility of the ball. This study compared the visual field of individuals when wearing an old helmet that does not conform to the new regulations, and the equivalent replacement which does. The visual field of 10 male participants was tested whilst wearing an old and new helmet. The new helmet resulted in a significant reduction in the visual field of the wearer (M = 66.1 out of 76 points seen in the new helmet vs. 74.8 seen with the old helmet), with the restriction predominantly confined to the superior visual field. The new regulations do appear to restrict the visual field of batters, confirming the anecdotal reports of players. However, the majority of this restriction occurs in the superior field, suggesting that the impact on batting performance may be limited. The importance of considering the impact that new helmet regulations can have on vision, batting performance, and player safety is discussed.     

"Show and tell" in the gymnasium revisited: developmental differences in modeling and verbal rehearsal effects on motor skill learning and performance.

Little research has investigated the observational learning process from a developmental perspective. The purpose of this study was to extend previous research by considering two factors: performance versus learning and sequencing versus form scores. Children (N = 60) comprising two age groups (5-0 to 6-11 and 8-0 to 9-11 years) were randomly assigned to verbal rehearsal only, model only, or model plus verbal rehearsal conditions. The task was a 6-part motor skill sequence in which proper sequencing and quality of form were assessed. A 2 x 3 x 4 (age group by model type by trial blocks) repeated measures MANOVA revealed a significant three-way interaction. Older children performed equally well under any of the model type conditions during both performance and learning. For younger children, a model plus rehearsal was superior to rehearsal only on sequence and form at performance and learning and superior to model only on sequence scores during the first two performance trial blocks. Model only and model plus rehearsal conditions were equally effective on form scores. These results suggest that age differences exist in the modeling of motor skills under conditions varying in model type, sequence and form scores, and performance and learning phases.