Coordination pattern of baseball pitching among young pitchers of various ages and velocity levels

This study compared the whole-body movement coordination of pitching among 72 baseball players of various ages and velocity levels. Participants were classified as senior, junior, and little according to their age, with each group comprising 24 players. The velocity levels of the high-velocity (the top eight) and low-velocity (the lowest eight) groups were classified according to their pitching velocity. During pitching, the coordinates of 15 markers attached to the major joints of the whole-body movement system were collected for analysis. Sixteen kinematic parameters were calculated to compare the groups and velocity levels. Principal component analysis (PCA) was conducted to quantify the coordination pattern of pitching movement. The results were as follows: (1) five position and two velocity parameters significantly differed among the age groups, and two position and one velocity parameters significantly differed between the high- and low-velocity groups. (2) The coordination patterns of pitching movement could be described using three components, of which the eigenvalues and contents varied according to age and velocity level. In conclusion, the senior and junior players showed greater elbow angular velocity, whereas the little players exhibited a wider shoulder angle only at the beginning of pitching. The players with high velocity exhibited higher trunk and shoulder rotation velocity. The variations among groups found using PCA and kinematics parameter analyses were consistent.     

高职教育汽车运用专业教材现状及改进建议

针对汽车运用专业教材存在的一些问题,应增加各科教师间的沟通和各科教材编审委员会之间的交流,树立基础课为专业课服务的思想;形成以企业需求为导向的思想,着力提高教师的实践能力;依托行业组织,加强教材建设和管理工作;考虑学生认知特点,合理表述知识;本着“必需“、“够用“、“管用“的原则,把握好教材的深度和广度.     

浅析台湾电子书平台的运营特色和创新实践--以台湾电子书店Readmoo平台为例

电子书产业是信息社会中涌现出来的新兴业态,近些年来展现出巨大的发展潜力,台湾地区由于市场规模小,资源紧缺,往往难以实现产业发展中的规模效应。针对这一现状,台湾电子书平台在运营中另辟蹊径,以“创新性”“体验性”和“社交性”为发展方向,致力于丰富电子出版物的内容,提升平台的服务质量,培养读者的阅读兴趣,在实践中不断壮大电子出版市场。本文以台湾地区电子书城Readmoo平台的经营经验为例,深入分析台湾电子书平台的创新实践和运营哲学。     

我国国有商业银行改革的利益主体分析

国有商业银行改革已成为决定我国整个经济能否健康发展的关键环节，以往的研究大多是从技术和体制上说明改革艰难的原因，章试图从一个新的角度来分析问题，即针对改革进程中涉及的各个利益主体改革前后的利益变化分析其改革艰难的因素，并提出协调利益主体之间冲突的方案，以推动改革的顺利进行。     

英语感叹句教学之我见

在英语句子中,有四大类句子,即陈述句、疑问句、祈使句和感叹句。在这四大类句子中,感叹句教学是比较困难的,本文揭示了关于如何让学生掌握好感叹句用法的一些教学方法。     

先秦儒家师生关系观及其启示

本文对先秦儒家师生关系观的特点、思想根源进行了论述和分析，针对当前我国一些学校中师生关系存在的问题。就如何借鉴先秦儒家师生关系观，构建21世纪新型师生关系提出了一些设想。     

李叔同教育思想的独特价值

李叔同是中国教育史上首屈一指的艺术教育大师。他学识渊博、多才多艺。在其早年的教育实践中 ,他一直倡导“不言之教”的教育思想 ,他这种德行结合、德才并重的教育思想时至今日 ,仍有其独特的社会价值。     

从一个Jigsaw活动看任务型教学

本文在介绍Jigsaw的有关信息的基础上，结合作者自己编写的Jigsaw来看它在任务型教学中的应用及与任务型教学的关系。     

住房贷款证券化法律问题初探

该介绍了住房贷款证券化的概念和特征，美国住房贷款证券化模式及其对我国的借鉴意义．对我国实行住房贷款证券化的前景进行分析，并对住房贷款证券化的相关法律问题进行初步的探讨。