Neuromuscular and technical abilities related to age in water-polo players

Testing is one of the important tasks in any multi-step sport programme. In most ball games, coaches assess motor, physical and technical skills on a regular basis in early stages of talent identification in order to further athletes’ development. The purpose of the study was to investigate anthropometric variables and vertical jump heights as a free throw effectiveness predictor in water-polo players of different age groups. Two hundred and thirty-six young (10–18 years) male water-polo players partitioned into three age groups underwent anthropometric variables’ measures and squat- and countermovement-jump tests, and performed water-polo free throws. Anthropometric variables, vertical jump heights and throw speed – as a proxy for free throw effectiveness – resulted different over age groups. Particularly, throw speed changed from 9.28 to 13.70 m · s^?1 (+48%) from younger to older players. A multiple-regression model indicated that body height, squat-jump height and throw time together explain 52% of variance of throw speed. In conclusion, tall height, high lower limb power and throwing quickness appeared to be relevant determinants for effective free throws. Such indications can help coaches during talent identification and development processes, even by means of novel training strategies. Further research is needed over different maturity statuses.     

Enhancing the practice of social work

This account of practice focuses on my learning and development as a new Action Learning Facilitator. It reflects on my thoughts and feelings as I began to facilitate my own sets a year or so ago. It will discuss and reflect on topics such as communication, feedback, expectations (both mine, the set members and the organisations), values, ethics, power and confidentiality. It opens with a personal reflection on my experience of becoming a set facilitator and then explores other aspects of my learning. It draws out, in particular, the links between Action Learning and social work and the ways in which the principles that underpin each of these are complementary and mutually enhancing.     

Enhancing the facilitation of online groups in higher education: a review of the literature on face-to-face and online group-facilitation

There still appears to be a gap between what online learning promises and what it can deliver in terms of student learning. Developments in online pedagogies and professional learning appear to lag behind the developments in technology and the promised benefits of technological transformation may not be realised. In this paper, we bring together perspectives that highlight vital aspects of online group-learning by reviewing the group-facilitation literature and the latest online learning literature to interrogate the pedagogical theories and practices currently used in online group-learning in higher education. We specifically focus on the interpersonal interactions between teachers and students, which are described in the online learning literature using the terms instructor immediacy, teaching presence, and social presence. We note differences in the literature regarding how teacher presence is interpreted and enacted and we expound the importance of the personal characteristics of the online teacher. Finally, we provide some signposts that might help course designers and teachers to improve online group learning: the intentional use of effective online learning pedagogies; a deeper understanding of what constitutes teacher presence; and strategies to enact that teacher presence with online groups. Recommendations for further research in online group facilitation are provided.     

教学即促进——厘清中学数学促进式教学中的几种关系

教学即促进。在中学数学教学中实施＂促进式教学＂,必须厘清五种关系,即师生促进、生生促进、媒介促进、自我促进、评价促进等五种促进关系。     

4~6岁幼儿移动性动作发展及神经肌肉控制研究

目的:研究4~6岁幼儿移动性动作发展的外在表现和神经肌肉控制的内在机制。方法:通过粗大动作发展测试(Test of Gross Motor Development-3,TGMD-3)对跑、蹦跳和单脚跳进行评价,用BTS表面肌电测试系统时域分析的方法对完成动作时肌肉的积分肌电(Integrated EMG,IEMG)和时序进行研究。采用方差分析探讨不同年龄移动性动作发展水平的差异,计算年龄组×不同肌肉对标准化iEMG的影响,年龄组×动作类型对标准化共收缩指数的影响,结果:4~6岁幼儿移动性动作发展水平和下肢肌群iEMG值存在年龄之间的差异性,其中单脚跳的差异性最为明显(P<0.05)。标准化iEMG值股直肌最大、胫骨前肌其次。随着年龄的增长和动作复杂程度的降低,股直肌/股二头肌和胫骨前肌/腓肠肌的共收缩指数峰值越来越大。结论:TGMD-3作为幼儿动作发展评价工具具有可行性,其中单脚跳可优先作为移动性动作技能定性评价指标,该动作下肢肌群iEMG值可作为定量评价的代表性指标。幼儿在跑、蹦跳和单脚跳动作时,主要用力肌肉为股直肌和胫骨前肌。随着年龄增长,完成移动性动作时,iEMG值逐渐增大,膝关节和踝关节周围肌群协调性逐渐增强。     

How information systems came to rule the world: Reflections on the information systems field

Abstract

Over some seven decades, a rather mundane transition that in its thoroughness and consequences has gone largely unacknowledged, has taken place, namely the revolution in modern information systems (IS) that guide organizations in their actions. Today, it is fair to say that IS have come to rule the world. They do this literally, by the rules they embody, which dictate how much of everyday life, as it relates to individuals and organizations and the transactions they engage in, takes place around the globe. In essence, IS have become important social and economic infrastructure. Seeking an understanding of how this has come about, I review historical developments in IS, focusing in particular on accounting systems, enterprise systems, retail automation, and electronic commerce. I argue that it is transactions and their facilitation that lie at the heart of IS and its development as a field of practice. I reflect on why this has gone mostly overlooked as such. I consider where we have now arrived with transaction facilitation as infrastructure and its importance in the light of current issues. I suggest how future studies might contribute to our learning more about where we should want to be with our transaction facilitation infrastructure.     

本体感受神经肌肉促进法（PNF）对提高机体平衡能力的研究

运用文献资料法、数理统计法、对比实验等方法研究本体感受神经肌肉促进法（PNF牵张法）对机体平衡能力的影响。结果显示：实验组和对照组在训练第8周和第16周后,动、静态平衡能力均有较大幅度提高。停训4周后,实验组学生动、静态平衡能力下降。说明运用PNF牵张法有助于改善机体的平衡能力。     

Taking a step back: learning without the facilitator on solo activities

The purpose of this study is to report on the nature of student learning resulting from an open facilitation approach to solo activities. Three key moments of facilitator intervention were identified at which the facilitator was encouraged to take a step back from directing the experience. They are the pre-activity brief, the mid-activity visit and the post-activity review. Findings suggest that participants' learning focused on their raised self-awareness and social relationships. Raised spiritual awareness was also identified and this was closely linked to a connection with the landscape and eco-system. Evidence was also identified for emergent learning to have occurred that is not normally identified in the solo discourse. The findings suggest that participants on solo activities do not require a facilitator to tell them what they should be learning and that they will identify for themselves outcomes that are personally meaningful and important.     

Resistance in action learning: struggling with self-efficacy and the social Self – and what about the set advisor?

This account of practice explores the concept of resistance in action learning. Resistance is conceptualized as an attempt of self-protection that is manifested in action learners' struggles with their sense of self-efficacy and their social Self. These struggles are an inherent part of the action learning process and may elicit defensive undercurrents that constrain learning. I contribute to debates on criticality in action learning by recognizing the centrality of resistance as a source of learning for participants and set advisors. The intended contribution of this paper is to illuminate the importance of engaging with these limiting processes which can spark a powerful learning experience that reverberates long after the action learning programme has finished. Furthermore, I reflect on the opportunities this alternative view on resistance may provide for us as action learning facilitators and discuss how we may incorporate these reflections in our practice.     

Corticospinal changes induced by fatiguing eccentric versus concentric exercise

The present study assessed neuromuscular and corticospinal changes during and after a fatiguing submaximal exercise of the knee extensors in different modes of muscle contraction. Twelve subjects performed two knee extensors exercises in a concentric or eccentric mode, at the same torque and with a similar total impulse. Exercises consisted of 10 sets of 10 repetitions at an intensity of 80% of the maximal voluntary isometric contraction torque (MVIC). MVIC, maximal voluntary activation level (VAL) and responses of electrically evoked contractions of the knee extensors were assessed before and after exercise. Motor evoked potential amplitude (MEP) and cortical silent period (CSP) of the vastus medialis (VM) and rectus femoris (RF) muscles were assessed before, during and after exercise. Similar reductions of the MVIC (?13%), VAL (?12%) and a decrease in the peak twitch (?12%) were observed after both exercises. For both VM and RF muscles, MEP amplitude remained unchanged during either concentric or eccentric exercises. No change of the MEP amplitude input–output curves was observed post-exercise. For the RF muscle, CSP increased during the concentric exercise and remained lengthened after this exercise. For the VM muscle, CSP was reduced after the eccentric exercise only. For a similar amount of total impulse, concentric and eccentric knee extensor contractions led to similar exercise-induced neuromuscular response changes. For the two muscles investigated, no modulation of corticospinal excitability was observed during or after either concentric or eccentric exercises. However, intracortical inhibition showed significant modulations during and after exercise.