跆拳道后横踢四种战术动作击打速度效果特点及对运动训练的启示     

徐春杰  刘卫军  刘德皓  于海龙 《成都体育学院学报》2020,(1):114-120

目的:研究跆拳道后横踢4种战术动作的击打速度效果及对运动训练的启示。方法:以跆拳道后横踢"进攻""迎击""反击""近身"4种战术动作为研究对象,运用Motion-Analysis红外光点高速运动捕捉测试系统,研究在"空击"状态下部分关节转动幅度,人体重心位移变化,膝关节和踝关节的速度、加速度;并运用电子护具采集后横踢4种战术动作的击打力量。结果:进攻、反击战术动作在骨盆、髋关节旋转上与迎击、近身战术动作有差异(P<0.05),而在躯干、膝和踝关节旋转上没有差异(P>0.05)。进攻、迎击、近身战术动作的提膝向心加速和踝关节离心加速好于"反击"(P<0.05)。进攻、迎击、近身战术动作的提膝速度、击打速度均高于"反击"(P<0.05),击打力量也高于"反击",尤其是"进攻"(P<0.05)。"进攻"和"反击"重心移动速度高于"迎击"和"近身"(P<0.01),向心加速度也高于"迎击"和"近身",尤其是"进攻"(P<0.05),但"反击"移动方向与击打方向相反。结论:跆拳道后横踢4种战术中,"进攻"与"反击","迎击"与"近身"动作结构类似;"进攻""迎击""近身"在整个过程中各环节动作肌肉收缩用力、动量传递、击打力量方面均优于"反击",特别是"进攻"显著优于"反击"。在运动训练中,要以比赛规则为导向,了解战术运用现状,科学提高击打速度,提升击打效果策略,更新运动训练思路。  相似文献   

The influence of water depth on kinematic and spatiotemporal gait parameters during aquatic treadmill walking     

Taeyou Jung  Yumi Kim  Hyosok Lim  Konstantinos Vrongistinos 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(3):297-307

The purpose of this study was to investigate kinematic and spatiotemporal variables of aquatic treadmill walking at three different water depths. A total of 15 healthy individuals completed three two-minute walking trials at three different water depths. The aquatic treadmill walking was conducted at waist-depth, chest-depth and neck-depth, while a customised 3-D underwater motion analysis system captured their walking. Each participant’s self-selected walking speed at the waist level was used as a reference speed, which was applied to the remaining two test conditions. A repeated measures ANOVA showed statistically significant differences among the three walking conditions in stride length, cadence, peak hip extension, hip range of motion (ROM), peak ankle plantar flexion and ankle ROM (All p values < 0.05). The participants walked with increased stride length and decreased cadence during neck level as compared to waist and chest level. They also showed increased ankle ROM and decreased hip ROM as the water depth rose from waist and chest to the neck level. However, our study found no significant difference between waist and chest level water in all variables. Hydrodynamics, such as buoyancy and drag force, in response to changes in water depths, can affect gait patterns during aquatic treadmill walking.  相似文献   

Validation of a videogrammetry technique for analysing American football helmet kinematics     

Ann Bailey  James Funk  David Lessley  Chris Sherwood  Jeff Crandall  William Neale 《Sports biomechanics / International Society of Biomechanics in Sports》2020,19(5):678-700

ABSTRACT

Professional American football games are recorded in digital video with multiple cameras, often at high resolution and high frame rates. The purpose of this study was to evaluate the accuracy of a videogrammetry technique to calculate translational and rotational helmet velocity before, during and after a helmet impact. In total, 10 football impacts were staged in a National Football League (NFL) stadium by propelling helmeted 50th percentile male crash test dummies into each other or the ground at speeds and orientations representative of concussive impacts for NFL players. The tests were recorded by experienced sports film crews to obtain video coverage and quality typically available for NFL games. A videogrammetry procedure was used to track the position and rotation of the helmet throughout the relevant time interval of the head impact. Compared with rigidly mounted retroreflective marker three dimensional (3-D) motion tracking that was concurrently collected in the experiments, videogrammetry accurately calculated changes in translational and rotational velocity of the helmet using high frame rate (two cameras at 240 Hz) video (7% and 15% error, respectively). Low frame rate (2 cameras at 60 Hz) video was adequate for calculating pre-impact translational velocity but not for calculating the translational or rotational velocity change of the helmet during impact.  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   

MATLAB在平面机构运动仿真中的应用     

刘立芳  徐鹏云 《保定师专学报》2008,21(2):50-52

探讨MATLAB软件在平面机构仿真中的应用,以铰链四连杆机构为例,建立平面机构运动仿真分析的数学模型。利用MATLAB进行编程求解、优化和动画仿真,为复杂的解析法计算提供便利的方法．  相似文献   

Forward Position Analysis of 5-DOF Parallel Mechanism     

齐明  梅江平 《天津大学学报(英文版)》2006,12(6):434-437

Forward position analysis is one of the importantand difficult issues in the kinematic analysis of paral-lel manipulators and has been extensively investiga-ted[1—3]. Most of the approaches for solving forwardposition problems of parallel manipulators with six de-grees of freedom (6-DOF), the Stewart platform forinstance, can be classified into two categories, i.e.closed-form analytical method using polynomial ap-proach and numerical method using iterative algo-rithm. Although the polynomial…  相似文献   

AutoCAD.VBA与MATLAB环境下工业机器人仿真系统     

梁飞华  邓宇  曾亚森  邢镇容 《茂名学院学报》2005,15(3):43-46

基于微机硬件系统和构建AutoCAD.VBA与MATLAB环境下的仿真软件平台开发和研制了一个“工业机器人三维参数化造型和动态仿真”软件,对ET-18HERO六转动关节机器人的运动学正反解问题、图形示教及轨迹规划等问题进行动态的分析与研究,整个程序采用了模块化程序设计方法及菜单技术和对话框等先进且功能齐全的人—机交互式对话方式,解决了机器人运动学仿真过程中的准确性、实时性与快速性三者之间的矛盾。  相似文献   

四连杆式独立悬架运动学分析与优化     

胡景煌  李明红  汪文龙 《天津工程师范学院学报》2006,16(3):27-31

建立了四连杆式悬架多刚体系统模型，并对车轮定位参数等特性进行了仿真，运用多目标函数的最优化方法对悬架的结构参数进行了优化，将优化前后的车轮定位参数运动学特性进行了对比，结果表明，悬架结构参数的优化对提高悬架性能具有重要作用。  相似文献   

中外优秀男子跳远运动员起跳技术运动学分析     

杨和健 《连云港职业技术学院学报》2004,17(2):75-78

通过对中外优秀男子跳远运动员起跳技术运动学分析，认为发展运动员短跑速度能力，提高起跳水平速度，起跳垂直速度和腾起角度，是当今优秀男子跳远运动员起跳技术的显著特征，也是影响跳远成绩的重要运动学指标。只有各项技术实现最佳组合和匹配，才能取得好成绩。  相似文献   

国内优秀男子跳板跳水运动员起跳技术的运动学分析     

郭梁  邹亮畴 《天津体育学院学报》2010,25(2):158-161

目的:进一步探讨立定跳板跳水起跳技术的生物力学规律.方法:采用影像分析法、数理统计法等方法,对何冲等7 gila优秀男子跳板跳水运动员起跳缓冲技术进行运动学分析.结果:与其他6名运动员相比.何冲缓冲时间最长(0.08 s),蹬伸压板时间最短(0.2 s),压板末肩关节角度最大141°.结论:髋、膝、踝在缓冲末较小的关节角度可以增加身体重心下降的高度,有利于压板;相关肌群肌肉力量是影响缓冲能力和蹬伸速度的决定因素.  相似文献