Assessment of three-dimensional joint kinematics of the upper limb during simulated swimming using wearable inertial-magnetic measurement units

The analysis of the joint kinematics during swimming plays a fundamental role both in sports conditioning and in clinical contexts. Contrary to the traditional video analysis, wearable inertial-magnetic measurements units (IMMUs) allow to analyse both the underwater and aerial phases of the swimming stroke over the whole length of the swimming pool. Furthermore, the rapid calibration and short data processing required by IMMUs provide coaches and athletes with an immediate feedback on swimming kinematics during training. This study aimed to develop a protocol to assess the three-dimensional kinematics of the upper limbs during swimming using IMMUs. Kinematics were evaluated during simulated dry-land swimming trials performed in the laboratory by eight swimmers. A stereo-photogrammetric system was used as the gold standard. The results showed high coefficient of multiple correlation (CMC) values, with median (first–third quartile) of 0.97 (0.93–0.95) and 0.99 (0.97–0.99) for simulated front-crawl and breaststroke, respectively. Furthermore, the joint angles were estimated with an accuracy increasing from distal to proximal joints, with wrist indices showing median CMC values always higher than 0.90. The present findings represent an important step towards the practical use of technology based on IMMUs for the kinematic analysis of swimming in applied contexts.     

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.     

Effects of tapering on physical match activities in professional soccer players

ABSTRACT

This study aimed to examine: (i) the effect of decreasing training load (TL) during taper weeks on physical match activities in professional soccer players, and (ii) to disclose the relationship between weekly TL and physical match activities. Rating of perceived exertion was collected after each training session and match to quantify the TL in 19 professional players over 17 standard and 7 taper weeks during the season. Physical match activities were quantified by a computerised match analysis system and compared between standard training and taper weeks. Compared to standard weeks, the duration and frequency of training sessions during the taper weeks decreased (?21.7% and ?18.8%, respectively; P < 0.01) with no change in intensity (?4.8%; P = 0.09). Consequently, the weekly TL decreased during the taper weeks (?25.5%; P < 0.01). Increases in distance covered by intense running (+15.1%; P < 0.05), high-intensity running (HIR) (+15.7%; P < 0.01), number of sprints (+17.8%; P < 0.05) and number of high-speed runs (+15.7%; P < 0.05) were observed during the seven matches played after the taper weeks. High relationships were observed between TL and HIR distance covered, number of HIR and number of sprints (r = ?0.53; r = ?0.55; r = ?0.65, respectively; P < 0.01). Decreasing TL during taper weeks by reducing training duration and frequency but maintaining intensity was associated with an increase in physical activities during matches. However, it needs to be determined whether tapering or other match factors led to the changes in match activity.     

黑龙江省冰雪装备制造业创新成长影响要素与战略研究

随着我国成功申办2022年冬奥会,我国将大力发展冰雪运动,并会随之带动旅游、经济和冰雪装备制造业的发展。而冰雪装备制造业的发展直接影响我国冰雪体育事业的开展。采用文献资料、调查、系统分析等研究方法,针对黑龙江省冰雪装备制造业的创新成长问题进行研究,并对黑龙江省的冰雪装备制造业创新成长影响要素以及企业创新成长存在的问题进行分析与总结,认为黑龙江省冰雪装备制造业创新成长的总体状况是良好的,但企业存在资金短缺,经营、管理、技术等方面人才匮乏,企业产品结构单一、产品科技创新意识和能力不强,欠缺可持续发展理念等问题。通过分析影响冰雪装备制造业创新成长的原因,提出引进与自我创新相结合、注重品牌质量、发扬政府主导优势等战略,旨为冰雪装备制造业在黑龙江省的发展提供理论依据。     

Are you a budding academic writer?

Academic writing can seem a daunting prospect although with the right support and information it can be more achievable than you think. In this first set of editorial comments of 2016, editors from all sections of the Health Information and Libraries Journal outline the origins of the individual section of the journal which they oversee and highlight some of the things you might want to consider when thinking of submitting your writing for publication.     

Big Data – What is it and why it matters

Big data, like MOOCs, altmetrics and open access, is a term that has been commonplace in the library community for some time yet, despite its prevalence, many in the library and information sector remain unsure of the relationship between big data and their roles. This editorial explores what big data could mean for the day‐to‐day practice of health library and information workers, presenting examples of big data in action, considering the ethics of accessing big data sets and the potential for new roles for library and information workers.     

陶行知"五解放"教育思想与大学生创新精神的培养

创新精神的培养是素质教育的核心内容之一，陶行知先生解放学生的大脑、双手、嘴巴、空间和时间的“五解放”教育思想是培养学生创新精神的重要手段，也是培养学生创新精神的前提，其实质就是真正把自主权交给学生。要培养大学生的创新精神，应该以“五解放”教育思想为指导，树立全新的创新教育观，努力培养大学生的创新意识和创造思维能力，全方位营造有利于培养创新精神的环境。通过创新精神的培养，造就更多与时俱进的创新型人才。     

Children’s emotional and behavioral responses to peer provocation and early school adjustment

ABSTRACT

Even very young children think about their own and others’ behavior, including emotions. Such cognitions and emotions about the self and others convey information that is crucial to social interactions and relationships. The current study based on an integrated model of emotion processes and cognition in social information processing (SIP) aimed to explore students’ emotional and behavioral responses in SIP choices, and their association with teacher-reported early school adjustment. Two-hundred and thirty pre-school and first-grade primary school students were interviewed using the Challenging Situations Task (CST). CST assessed students’ emotional and behavioral responses to 12 unambiguous hypothetical peer provocation situations. Children’s preschool and first-grade primary teachers rated children’s early school adjustment with the Social Competence and Behavior Evaluation (SCBE-30) measure. The results revealed that children chose mainly sad and angry emotions and socially competent and passive behaviors. We found a relationship both between sad emotions and socially competent behavior choices, and between angry emotion and aggressive behavior choices. Sad emotions and aggressive behavior choices were the main predictors of school adjustment. Children’s responses to peer provocation situations varied depending on how the children interpreted the situations. The results address the importance of children’s SIP and school adjustment.     

教育市场化刍议

本文对市场经济条件下教育能否实行市场化进行了探讨,认为教育可以实行市场化,但不能完全市场化,应该区别对待,并进一步提出相应的策略。