Joint work is not shifted proximally after a long run in rearfoot strike runners     

Jake A. Melaro  Allison H. Gruber 《Journal of sports sciences》2021,39(1):78-83

ABSTRACT

Distal-to-proximal redistribution of joint work occurs following exhaustive running in recreational but not competitive runners but the influence of a submaximal run on joint work is unknown. The purpose of this study was to assess if a long submaximal run produces a distal-to-proximal redistribution of positive joint work in well-trained runners. Thirteen rearfoot striking male runners (weekly distance: 72.6 ± 21.2 km) completed five running trials while three-dimensional kinematic and ground reaction force data were collected before and after a long submaximal treadmill run (19 ± 6 km). Joint kinetics were calculated from these data and percent contributions of joint work relative to total lower limb joint work were computed. Moderate reductions in absolute negative ankle work (p = 0.045, Cohen’s d = 0.31), peak plantarflexor torque (p = 0.004, d = 0.34) and, peak negative ankle power (p = 0.005, d = 0.32) were observed following the long run. Positive ankle, knee and hip joint work were unchanged (p < 0.05) following the long run. These findings suggest no proximal shift in positive joint work in well-trained runners after a prolonged run. Runner population, running pace, distance, and relative intensity should be considered when examining changes in joint work following prolonged running.  相似文献   

A biomechanical comparison of conventional classifications of bowling action-types in junior fast bowlers     

Andrew Schaefer  Rene E. D. Ferdinands  Nicholas O’Dwyer 《Journal of sports sciences》2020,38(10):1085-1095

ABSTRACT

Fast bowling is categorised into four action types: side-on, front-on, semi-open and mixed; however, little biomechanical comparison exists between action types in junior fast bowlers. This study investigated whether there are significant differences between action-type mechanics in junior fast bowlers. Three-dimensional kinematic and kinetic analyses were completed on 60 junior male fast bowlers bowling a five-over spell. Mixed-design factorial analyses of variance were used to test for differences between action-type groups across the phases of the bowling action. One kinetic difference was observed between groups, with a higher vertical ground reaction force loading rate during the front-foot contact phase in mixed and front-on compared to semi-open bowlers; no other significant group differences in joint loading occurred. Significant kinematic differences were observed between the front-on, semi-open and mixed action types during the front-foot contact phase for the elbow and trunk. Significant kinematic differences were also present for the ankle, T12-L1, elbow, trunk and pelvis during the back-foot phase. Overall, most differences in action types for junior fast bowlers occurred during the back-foot contact phase, particularly trunk rotation and T12-L1 joint angles/ranges of motion, where after similar movement patterns were utilized across groups during the front-foot contact phase.  相似文献   

Scapular motion adaptations in junior overhead athletes: a three-dimensional kinematic analysis in tennis players and non-overhead athletes     

Elif Turgut  Filiz Fatma Colakoglu  Gul Baltaci 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(3):308-316

Adult overhead athletes without a history of shoulder injury show scapular adaptations. There is a lack of detailed assessment of scapular kinematics in junior overhead athletes. This study aims to investigate three-dimensional scapular kinematics in junior overhead athletes. We recruited a total of 20 junior tennis players and 20 healthy children without participation in any overhead sports in this study. Bilateral scapular kinematic data were recorded using an electromagnetic tracking device for scapular plane glenohumeral elevation. The data were further analysed at 30°, 45°, 60°, 90° and 120° during glenohumeral elevation and lowering. Statistical comparisons of the data between groups (junior overhead athletes and non-overhead athletes) and sides (serve dominant and non-dominant shoulders of the overhead athletes) were analysed with the ANOVA. Comparisons showed that, in general, the scapula was more upwardly rotated and anteriorly tilted in overhead athletes when compared to non-overhead athletes, however there was no side-to-side differences when serve dominant and non-dominant shoulders compared in junior overhead athletes. The serve dominant arm of junior overhead athletes had alternations in scapular kinematics when compared with the non-overhead athletes. These findings provide clinical evaluation implications and the need for clinicians to assess for potential adaptations in junior overhead athletes.  相似文献   

民国前期绥远地区汉族妇女由缠足到放足的嬗变     

陶继波  马晓辉 《内蒙古大学学报(人文社会科学版)》2004,36(3):70-74

绥远地区汉族妇女的放足滥觞于清末。经过官府和一些官绅多年的大力提倡与劝禁。到民国前期取得了一定的成效。然而．通过对放足过程的透视。我们可以看到，缠足与放足的冲突是曲折复杂的。这充分印证了妇女从缠足到天足的进程是渐变的。并非一蹴而就。  相似文献   

生物医学工程:一个发展迅速值得关注的交叉学科——生物力学、组织工程学、生物材料与人工器官   总被引：4，自引：0，他引：4  

李恩中  曹河圻  杜生明 《中国科学基金》2006,20(3):153-158

生物医学工程学（Biomedical Engineering，BME）是包含多种技术并相互交叉融合的一门科学。它综合了生物学、医学与工程学的理论和方法，研究生命体的构造、功能、状态和变化，研究新材料、新技术、新仪器设备，用于防病、治病、保护人民健康和提高医学水平。涉及科学领域广泛，除生物学、医学外，还有电子学、微电子学、现代计算机技术、化学、高分子化学、力学、近代物理学、光学、射线学、精密机械和近代高技术，并在不断发展扩大，是各国争相大力发展的高技术之一。本文主要从生物力学、组织工程学、生物材料与人工器官等方面进行探讨。  相似文献   

鸡西煤田穆棱矿城子河组的含煤建造与沉积特征     

王培坤 《鸡西大学学报》2004,4(3):55-56

城子河组在鸡西煤田分布甚广，含有主要可采煤层，煤层形成的最好环境是滨海沉积带还原环境，在地壳下降速度与植物死亡堆积速度均衡条件下能形成较厚的煤层。如平阳区。  相似文献   

划船式短跑途中跑技术脚着地期间的生物力学分析     

蒋炜  朱勇 《渭南师范学院学报》2005,20(2):75-79

"后蹬式或屈蹬式短跑途中跑技术脚着地期间的生物力学分析经典理论"是在脚着地期间先"缓冲"、再"后蹬"的生物力学分析理论,文章提出的"划船式短跑途中跑技术脚着地期间的生物力学分析理论"合理解释了短跑途中跑前支撑时期是主要动力来源,后支撑时期着地腿的运动是前支撑时期转动—平动的继续  相似文献   

从“女士放足被逼毙命案”看晚清的不缠足运动     

王洪军  龚玉华 《郧阳师范高等专科学校学报》2005,25(4):58-60

晚清的不缠足运动,是近代妇女解放运动的重要组成部分,也是一场社会习俗改革的运动。刊登在当时《申报》上的几则有关“女士放足被逼毙命案”的消息,有助于我们了解当时这场运动的大致情形。  相似文献   

《雪夜林畔》译文评析--弗罗斯特诗歌译作论     

陈倩 《廊坊师范学院学报》2004,20(3):21-23

通过分析弗罗斯特的诗歌《雪夜林畔》的一篇中译文，评价了它在传达原文的思想内容、语言风格及翻译技巧方面的特点。诗是内容和形式高度融合的有机统一体，诗歌的翻译要求我们传达的不仅是内容和风格，还有它的形式。  相似文献   

基于生物力学视角下对女子足球鞋发展的分析     

朱煜林 《教育教学论坛》2019,(18):107-109

本文采用文献资料法、数理统计法和归纳法,以生物力学为基础分析女子足球鞋对于女子运动员运动表现提高和运动损伤防治方面的必要性。结论表明:球鞋与场地表面的互相作用能够决定牵引力特性是否对运动员合适。挑选足球鞋鞋底构造应该根据场地条件或季节性变化而定。球鞋与场地相配合从而使运动员能够高效地做出动作和移动。球鞋的前部应与个人的足部形态相匹配。每个运动员的足部形态都不同,鞋与脚的正确搭配能帮助运动员保持他们的最佳表现。  相似文献