湖北女子举重运动员挺举技术动作生物力学分析

女子举重是我国的优势项目,是我国奥运金牌的重点项目.对挺举技术进行运动生物力学研究,对于保持我国在世界举重领域的领先地位,发展我国的奥运战略具有重要意义.借助三维常速摄像和视频解析系统,运用运动生物力学原理和方法,对我困优秀女子举重运动员的挺举技术进行测试和分析,试图揭示这一技术的运动学特征及原理,并对运动员动作技术的...     

对李艳凤双腿支撑起转阶段肩、髋、膝关节的三维运动学分析

利用三维常速摄像系统,采用定点定机摄像方法对李艳凤的技术动作进行解析,具体以旋转阶段双腿支撑起转环节肩、髋、膝关节的运动学分析为重点.通过对此技术环节的三维运动学分析,可以更好地指导运动训练,为我国的铁饼技术提供较系统的,有针对性的理论支持.     

武术腾空摆莲720°接马步的运动学分析

本文采用运动生物力学的三维摄像解析法对武术腾空摆莲720°接马步动作进行运动学分析,揭示该动作的运动学特征,为提高动作质量,改进动作技术提供参考。     

对武术套路运动中仰身平衡和燕式平衡的肌电及运动学比较研究

运用三维图像解析系统,采用三维摄像、三维测力台和表面肌电仪对两组不同级别男子武术套路运动员的仰身平衡和燕式平衡动作进行运动学、动力学和肌电学方面的研究,从生理学和运动生物力学角度分析仰身平衡和燕式平衡的技术特征和力学原理。     

对武术套路运动中仰身平衡和燕式平衡的肌电及运动学比较研究

运用三维图像解析系统,采用三维摄像、三维测力台和表面肌电仪对两组不同级别男子武术套路运动员的仰身平衡和燕式平衡动作进行运动学、动力学和肌电学方面的研究,从生理学和运动生物力学角度分析仰身平衡和燕式平衡的技术特征和力学原理。     

中外优秀男排运动员跳发球技术的运动学分析

运用三维摄像及三维录像解析法，对中国男排队员跳发球技术进行分析。主要研究结论是：跳发球的空中击球动作是以躯干的转体、伸肩及收腹带动挥臂的三维运动；挥臂击球时手的瞬时加速度大小是决定跳发球威力的关键因素之一。     

优秀110米跨栏运动员尹靖第五栏跨栏技术运动学比较分析

以四川省优秀跨栏运动员尹靖为研究对象对第13届亚洲田径大奖赛男子110m栏测试赛上的第5栏跨栏动作技术进行运动生物力学三维摄像解析,获得运动学参数进行分析探究其动作技术上存在的问题,为跨栏运动技术训练提供参考.     

对优秀速滑运动员于凤桐起跑技术的运动学分析

采用三维摄像DLT法,用3台松下M9000摄像机在比赛条件下分别从侧面和正面进行同步定点、定焦拍摄,完整记录了参加第10届全国冬运会500 m速滑比赛的于凤桐等10余名运动员起跑前后约16 m范围内的运动过程,旨在揭示于凤桐起跑的动作特点.研究结果表明:起跑阶段步频较高是于凤桐起跑速度快的重要因素;于凤桐起跑预备姿势两支撑点间距小,前稳定角小,其重心低而偏前,为完成从静止状态转入快速起动蹬冰状态创造了有利条件;在起动过程中,利用重心高度起伏较小,蹬冰角与上体前倾角较接近的特点,获得了较大的重心速度,以较高的频率完成了起动蹬冰动作.     

对中、日男子速滑运动员500m比赛起跑动作的比较研究

采用三维摄像DLT法,用3台松下M9000摄像机在比赛条件下分别从侧面和正面进行同步定点、定焦拍摄,完整记录了参加2003年世界杯哈尔滨站男子500m速滑比赛的中、日10名运动员起跑前后约16 m范围内的运动过程,旨在揭示中、日运动员起跑的动作特点.研究结果表明:中国运动员起跑预备姿势支撑点间距小,前稳定角小,其重心较偏前,为完成从静止状态转入快速起动蹬冰状态创造了有利的条件,其稳定性略低于日本运动员;疾跑阶段日本运动员的步频高于中国运动员,中国运动员步幅明显大于日本运动员,中国运动员的起跑效果优于日本运动员.     

竞技武术套路C级高难度动作323C+4的生物力学分析

采用运动生物力学的三维摄像解析法，对4名武英级运动员323C＋4动作进行运动学分析，指出起跳、腾空和落地每一阶段的动作要求，并结合日常训练提出相应对策。     

A simple mechanical model for simulating cross-country skiing,skating technique

The role of simulation models in sport disciplines has become relevant lately due to the multiple advantages that they may offer sports teams, coaches and practitioners. This paper develops and presents a simple three-dimensional multibody dynamic model of a cross-country skier, modeling a single propulsion phase to obtain the kinetic parameters involved in the movement. A professional Olympic-level skier performed the skating technique without poles in a ski tunnel under controlled conditions and on an incline plane. Then, with a force acquisition system attached to the ski bindings and a motion capture system set on site, the leg resultant forces and the movement of specific points of the skier’s lower body were acquired. The data obtained from the motion capture system were used as the prescribed kinematic input data in the multibody model and the measured force was used later as a parameter of comparison with the results of the simple model. After simulating the technique, the calculated resultant forces seem to be in agreement with those measured in the field.     

速滑运动分析中多台摄像机视频同步问题的研究

在速滑运动分析中处理多角度视频信息时,需要首先解决的是多台摄像机同步问题。提出单脉冲触发同步方式,外部脉冲发生器同步方式,时钟同步方式等几种多台摄像机同步方式。并针对多角度视频信息处理常见的外同步、电源同步和控制中心模拟方式同步等问题提出相应的处理方式与解决方案,为实现多台摄像机高度同步作业提供参考依据。     

Validation of an integrated experimental set-up for kinetic and kinematic three-dimensional analyses in a training environment

Biomechanical analyses using synchronized tools [electromyography (EMG), motion capture, force sensors, force platform, and digital camera] are classically performed in a laboratory environment that could influence the performance. We present a system for studying the running sprint start that synchronizes motion capture, EMG, and ground reaction force data. To maximize motion capture (Vicon 612 with six cameras), a special dim environment was created in the stadium. "Classical" tools were combined with "purpose-built" tools intended to analyse the different aspects of movement. For example, a synchronization system was built to create a common time-base for all data recordings and a portable EMG system was synchronized by a cable that was "disconnected" by the athlete's movement out of the blocks. This disconnection represented an independent event recorded by different tools. A "gap" was measured for some sprint start events between kinetic and kinematic (motion capture) data. Calibration results, measurements of time "gap", and duration of the independent event were used to validate the accuracy of motion capture and the synchronization system. The results validate the entire experimental set-up and suggest adjustment values for motion capture data. This environment can be used to study other movements and can easily be applied to several sports.     

Validation of a videogrammetry technique for analysing American football helmet kinematics

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.     

黑龙江省雪上运动资源与环境的可持续发展研究

综合运用文献资料法、数理统计法、逻辑分析法等研究方法,对黑龙江省冬季雪上运动资源现状、影响雪上运动环境的因素进行研究,探索优化利用雪上运动资源的方法,提出要具备承办大型赛事的综合能力、提高赛后经营管理的能力、增强赛后滑雪资源与环境的可持续性等可持续性发展的途径,为逐步改善雪上运动环境,进一步提升黑龙江省承办大型国际、国内滑雪赛事的综合能力,促进赛后滑雪运动环境与资源利用的可持续性提供理论依据。     

Automatic measurement of key ski jumping phases and temporal events with a wearable system

We propose a new method, based on inertial sensors, to automatically measure at high frequency the durations of the main phases of ski jumping (i.e. take-off release, take-off, and early flight). The kinematics of the ski jumping movement were recorded by four inertial sensors, attached to the thigh and shank of junior athletes, for 40 jumps performed during indoor conditions and 36 jumps in field conditions. An algorithm was designed to detect temporal events from the recorded signals and to estimate the duration of each phase. These durations were evaluated against a reference camera-based motion capture system and by trainers conducting video observations. The precision for the take-off release and take-off durations (indoor < 39 ms, outdoor = 27 ms) can be considered technically valid for performance assessment. The errors for early flight duration (indoor = 22 ms, outdoor = 119 ms) were comparable to the trainers' variability and should be interpreted with caution. No significant changes in the error were noted between indoor and outdoor conditions, and individual jumping technique did not influence the error of take-off release and take-off. Therefore, the proposed system can provide valuable information for performance evaluation of ski jumpers during training sessions.     

Effects of an inclined board as a training tool on the take-off motion of the long jump

In this study, we investigated the effects of inclined and raised flat boards on the take-off motion of the long jump to determine the effectiveness of these boards as training tools. Eight male long jumpers were videotaped with two high-speed video cameras (250 Hz) set perpendicular to the runway. Four different jumps were performed with in four conditions, all with their medium length run-up: a long jump with their normal technique, long jumps on upward inclined boards of two different inclinations (2.5 and 5.0 degrees), and a long jump on a raised flat board (0 degrees, 50 mm). The raised flat board enhanced the pivot of the body over the take-off foot, and reduced flexion of the take-off leg knee. However, the inclined boards did not produce the same effects as the raised flat board. The use of the inclined boards increased the vertical velocity of the centre of mass of the body at toe-off, resulting in increased airborne time. These results suggest that the raised flat board and inclined boards would be effective in improving long jumpers' techniques during the take-off and airborne phases.     

大型滑雪旅游度假区建设的制度环境:内涵认知、困境与需求导向

制度环境是大型滑雪旅游度假区建设的关键性支撑,从制度环境角度推动大型滑雪旅游度假区的建设更科学、有效。通过文献分析、制度分析及实地考察等方法,对大型滑雪旅游度假区的内涵、特征、现状、困境及需求趋势与导向进行了判断。研究得出,大型滑雪旅游度假区建设的制度环境是聚焦于大型滑雪旅游度假区建设、运营密切相关的基本制度而形成的,这种制度环境要求有效性,呈现出与运营主体、特定区域及自身适应性的特征;现有制度环境虽然日益完善,但仍然形成了制度环境滞后、制度组成单一及各参与主体缺乏有机融合的困境。正式制度的需求导向指向大型滑雪旅游度假区建设的引导和规范两个层面,非正式制度的需求导向指向了冬季体育文化、冬季运动价值观念,冬季体育传统及相关意识形态。     

三维运动分析中定标问题的简化模型

在三维运动分析中,从分析直接线性变换算法(DLT模型)对单摄像机和双摄像机的标定方程出发,利用坐标转换方法得出一种简单适用的简化模型,为解决实践中快速确定三维运动空间坐标问题提供理论分析依据。     

跆拳道横踢、侧踢技术参数解析与评价指标建立

通过200 fps高速摄像采集17名备战全运会跆拳道运动员的横踢、侧踢主动攻击技术影像。以Dartfish6.0运动技术分析模块为例，从运动影像采集、指标选定、运动技术参数解析整个分析过程出发，旨在探究跆拳道横踢、侧踢运动技术参数解析与指标参数采集，试图建立两项技术的运动学参数评价指标，为进一步运动技术评价诊断提供参考。