Comparison of split double and triple twists in pair figure skating

In this study, we compared the kinematic variables of the split triple twist with those of the split double twist to help coaches and scientists understand these landmark pair skating skills. High-speed video was taken during the pair short and free programmes at the 2002 Salt Lake City Winter Olympics and the 2003 International Skating Union Grand Prix Finals. Three-dimensional analyses of 14 split double twists and 15 split triple twists from eleven pairs were completed. In spite of considerable variability in the performance variables among the pairs, the main difference between the split double twists and split triple twists was an increase in rotational rate. While eight of the eleven pairs relied primarily on an increased rotational rate to complete the split triple twist, three pairs employed a combined strategy of increased rotational rate and increased flight time due predominantly to delayed or lower catches. These results were similar to observations of jumps in singles skating for which the extra rotation is typically due to an increase in rotational velocity; increases in flight time come primarily from delayed landings as opposed to additional height during flight. Combining an increase in flight time and rotational rate may be a good strategy for completing the split triple twist in pair skating.     

Using Principal Components Analysis to Identify Individual Differences in Vertical Jump Performance

Purpose: The purpose of this study was to determine the reliability of cardiorespiratory and pelvic kinematic responses to simulated horseback riding (SHBR) and to characterize responses to SHBR relative to walking in apparently healthy children. Method: Fifteen healthy children (M_age = 9.5 ± 2.6 years) completed SHBR on a commercially available simulator at low intensity (0.27 Hz) and high intensity (0.65 Hz) during 3 sessions on different occasions. Heart rate (HR), blood pressure, and respiratory gases were measured at rest and during steady-state exercise at both intensities. Pelvic displacement was measured during steady-state exercise. Rate of energy expenditure, mean arterial pressure, and rate pressure product (RPP) were calculated. Participants also walked on a treadmill for 26.8 m/min to 80.5 m/min in 13.4-m/min increments at 0% grade during 1 session to compare cardiorespiratory responses with those of SHBR. Results: Physiological variables across all 3 SHBR sessions were similar at both intensities (p>.05 for all). Intraclass correlation coefficients (ICCs) and coefficients of variation indicate good to modest reliability of cardiorespiratory measures during SHBR (ICCs = .542–.996 for oxygen consumption, energy expenditure, and RPP). Cardiorespiratory variables, except for HR, were 2% to 19% greater, and pelvic displacement was up to 37% greater with high-intensity riding. Treadmill walking at all speeds elicited greater physiological responses compared with SHBR (p < .05). Conclusion: Cardiorespiratory responses and pelvic kinematics are reproducible with SHBR in young children, and these responses were lower than those elicited by slow treadmill walking.     

For Young Jumpers,Differences are in the Movement's Control,Not its Coordination

Abstract

Previous research on the development of jumping has indicated that the coordination of the jump is stable from its inception, but that individual differences lie in the control of the task. The purpose of this study was to examine control in the vertical jump as performed by novice jumpers. Two groups of children who varied in their ability to regulate the takeoff angle were compared on measures of coordination and control. The children's groups were also compared to a group of skilled adults. Both children's groups demonstrated temporal coordination patterns comparable to the adult pattern, though the children were distinguished from the adults on selected spatial (control) measures. The results indicate that a mature pattern of coordination for the jump exists at the earliest stages of the behavior's appearance in the movement repertoire. The novice, however, lacks the ability to precisely control, or tune, the movement to task demands.     

不同级别跳远运动员专项力量指标与专项成绩的相关研究

以我国不同级别男子跳远运动员48名为研究对象,运动员运动等级为健将级、一级、二级各16名,运用文献资料法、问卷调查法、因子分析法、逐步回归分析法、多元回归分析法、数学建模法建立预测专项成绩的专项力量指标方程.结果表明：我不同级别的运动员预测专项成绩的专项力量指标存在差异性,各预测模型均可作为预测该级别运动员的专项力量水平模型.     

三级跳远初学者核心力量的实验训练研究

以曲靖师范学院体育学院2008级田径专修班的8名三级跳远初学者为研究对象,进行4个单元16个周的核心力量训练。结论显示:受训者的助跑姿势、助跑速度、跳跃中的身体重心稳定性得到不同程度的有效提高,技术进一步完善,专项成绩提高明显。     

中国优秀女子三级跳远运动员跨步跳起跳着地瞬时的运动生物力学分析

运用运动学、动力学、肌电图学等,结合摄像解析法,分析中国优秀女子三级跳远运动员跨步跳起跳着地瞬时的动作。研究发现:着地角普遍偏小,与国外优秀女子选手相比差异具有高度显著性;半腱肌的用力程度始终最大;三个方向上有不同程度的力产生,垂直方向的分力最大。     

二胡柔弦的要素和练习作品《大车谣》

二胡演奏中的柔弦技法,是提升音乐美感,增强演奏表现力,促进音乐流动,活跃气氛的主要手段之一,也是演奏者的风格个人标签。柔弦是一个综合技术过程,与二胡基本功、音准、作品处理等关系密切,并不容易掌握好。文章从基本功与柔弦关系的剖析,从演奏姿势与柔弦技法、把位与柔弦的关系、长弓对柔弦的帮助以及柔弦练习作品《大车谣》的练习心得等几个方面阐述,对柔弦之奥秘进行有益的探索。     

高校学科交融应建立长效机制

学科交融是学科建设和发展新的增长点,多年来高校虽然重视和关注学科交融,但是缺少领导、组织、管理和保障等机制,使得学科交融工作不能有效地开展。在科技发展呈现速度加快、急剧变化的今天,我国高校加强学科交融工作已刻不容缓,应在学科交融的实现机制上下工夫,扎扎实实,才能将这项工作做出成效。     

汽车4S店推行8S管理的有效途径探析

分析了我国现阶段汽车4S店管理过程中普遍存在的问题,对汽车4S店推行8S现场管理的途径进行实证研究,并提出建立8S管理长效机制的可行性方案,以期提升企业竞争力.     

国外三级跳远项目研究热点与演进——基于知识图谱的可视化分析

运用CitespaceV软件,对Web of Science核心合集数据库收录的主题为“Triple Jump”的期刊文献,进行可视化分析。研究表明:在国际范围内,美国最为关注三级跳远项目的研究,而英格兰、意大利在三级跳远研究领域具有较高的影响力。国外三级跳远项目研究热点主要为提升运动表现、生物力学分析、运动损伤与康复等。2004-2020年期间,三级跳远项目没有出现明显的研究分支与阶段划分,研究始终围绕着提升运动表现、运动损伤康复等基本内容展开。