Quantitative assessment of developmental levels in overarm throwing using wearable inertial sensing technology

Motor proficiency in childhood has been recently recognised as a public health determinant, having a potential impact on the physical activity level and possible sedentary behaviour of the child later in life. Among fundamental motor skills, ballistic skills assessment based on in-field quantitative observations is progressively needed in the motor development community. The aim of this study was to propose an in-field quantitative approach to identify different developmental levels in overarm throwing. Fifty-eight children aged 5–10 years performed an overarm throwing task while wearing three inertial sensors located at the wrist, trunk and pelvis level and were then categorised using a developmental sequence of overarm throwing. A set of biomechanical parameters were defined and analysed using multivariate statistics to evaluate whether they can be used as developmental indicators. Trunk and pelvis angular velocities and time durations before the ball release showed increasing/decreasing trends with increasing developmental level. Significant differences between developmental level pairs were observed for selected biomechanical parameters. The results support the suitability and feasibility of objective developmental measures in ecological learning contexts, suggesting their potential supportiveness to motor learning experiences in educational and youth sports training settings.     

武术搏击训练的运动反应能力研究

武术搏击对运动员的身体素质要求较高,为确保运动反应能力的有效提升,增强武术搏击训练的质效,促进完善武术搏击运动体系的形成。在武术搏击比赛中,运动员的身体反应能力将直接关系到武术搏击比赛的结果,因此在日常的武术搏击训练中,加强对运动员反应能力的培训以此来提高其搏击的水平至关重要,具有探究分析的价值意义。本文着眼于实际,从多个维度出发,系统探讨武术搏击训练过程中运动员反应能力的提升方法,以期逐步构建起完备的武术搏击训练体系,全面提升现阶段武术搏击训练体系,切实满足现阶段武术搏击训练的相关要求,不断增强运动反应能力。     

From the field of play to the laboratory: Recreating the demands of competition with augmented reality simulated sport

ABSTRACT

Biomechanical analysis has typically been confined to a laboratory setting. While attempts have been made to take laboratory testing into the field, this study was designed to assess whether augmented reality (AR) could be used to bring the field into the laboratory. This study aimed to measure knee load in volleyball players through a jump task incorporating AR while maintaining the perception-action couplings by replicating the visual features of a volleyball court. Twelve male volleyball athletes completed four tasks: drop landing, hop jump, spike jump, and spike jump while wearing AR smart glasses. Biomechanical variables included patellar tendon force, knee moment and kinematics of the ankle, knee, hip, pelvis and thorax. The drop landing showed differences in patellar tendon force and knee moment when compared to the other conditions. The hop jump did not present differences in kinetics when compared to the spike conditions, instead of displaying the greatest kinematic differences. As a measure of patellar tendon loading the AR condition showed a close approximation to the spike jump, with no differences present when comparing landing forces and mechanics. Thus, AR may be used in a clinical assessment to better replicate information from the competitive environment.     

高职高专电机与拖动课程教学改革探讨

随着高职高专教学改革的深入,电机与拖动课程教学学时将大幅度减少,要达到预期的教学效果,必须从多方面进行教学改革。在教学实践和调研的基础上提出了一些具体的教改措施。     

素质教育与新课程体育考试的改革

体育课的考试是体育课教学的重要环节之一,看似简单的技评,实为蕴含着对技术动作质量高标准的要求。文中论述了技评考核对素质教育的显性作用,全面反映学生掌握运动技能的情况,并结合体育教学实际情况提出了具体的操作方法,这种多元综合评价的方式,对推进体育素质教育具有积极的意义。     

Parental writing support and preschoolers’ early literacy,language, and fine motor skills

The current study examines the nature and variability of parents’ aid to preschoolers in the context of a shared writing task, as well as the relations between this support and children's literacy, vocabulary, and fine motor skills. In total, 135 preschool children (72 girls) and their parents (primarily mothers) in an ethnically diverse, middle-income community were observed while writing a semi-structured invitation for a pretend birthday party together. Children's phonological awareness, alphabet knowledge, word decoding, vocabulary, and fine motor skills were also assessed. Results revealed that parents provided variable, but generally low-level, support for children's approximation of sound-symbol correspondence in their writing (i.e., graphophonemic support), as well as for their production of letter forms (i.e., print support). Parents frequently accepted errors rather than asking for corrections (i.e., demand for precision). Further analysis of the parent–child dyads (n = 103) who wrote the child's name on the invitation showed that parents provided higher graphophonemic, but not print, support when writing the child's name than other words. Overall parental graphophonemic support was positively linked to children's decoding and fine motor skills, whereas print support and demand for precision were not related to any of the child outcomes. In sum, this study indicates that while parental support for preschoolers’ writing may be minimal, it is uniquely linked to key literacy-related outcomes in preschool.     

Motor Development: Exploring the motor competence of 4-year-old Norwegian children

This study set out to explore motor competence in 4-year-old children. This age group has not been previously tested in Norway. Ninety-one 4-year-old children from ten nursery schools were tested using the Movement ABC test. The most striking finding was that only one out of 91 children would be classified as clumsy within the fifth percentile of the USA norms, with seven children being 'borderline'. The study also showed that out of the eight children failing in the motor impaired and borderline groups, seven were boys. Clear sex differences were also apparent in the development of motor skills. On the total scores and in the two of three sections (manual dexterity and balance) boys were significantly worse than girls. There were no significant differences between the sexes with respect to ball skills competence.     

基于单片机直流电机控制系统设计

本文设计了以单片机AT89S52为控制核心,以L298作为驱动的PWM直流调速系统。系统采用数字PID控制算法,实现了转速的闭环控制。系统可通过键盘设定电机的状态和期望转速,同时实时数码显示转速。