Acceleration patterns in the lower and upper trunk during running     

Masahiro Kawabata  Kenta Goto  Ken Sasaki  Eiji Hihara  Takahiro Mizushina 《Journal of sports sciences》2013,31(16):1841-1853

Abstract

The purpose of the present study was to relate 3D acceleration patterns of the lower and upper trunk during running to running gait cycle, assess the validity of stride duration estimated from acceleration patterns, investigate speed-dependent changes in acceleration, and examine the test–retest reliability of these parameters. Thirteen healthy young men performed two running trials each on a treadmill and on land at three speeds (slow, preferred, and fast). The 3D accelerations were measured at the L3 spinous process (lower trunk) and the ensiform process (upper trunk) and synchronised with digital video data. The amplitude and root mean square of acceleration and stride duration were calculated and then analysed by three-way analysis of variance to test effects of running conditions, device location, and running speed. Bland-Altman analysis was used to evaluate the test–retest reliability. Marked changes in acceleration were observed in relation to foot strike during running. Stride durations calculated from the vertical accelerations were nearly equal to those estimated from video data. There were significant speed effects on all parameters, and the low test–retest reliability was confirmed in the anterior–posterior acceleration during treadmill running and the anterior–posterior acceleration at slow speed during treadmill and overground running.  相似文献   

Relationship between Working Environment,Self-Concept,Real-Ideal Self Discrepancy,and Functionality in Physical Education Teachers     

Milton G. Holmen  Bonnie L. Parkhouse 《Research quarterly for exercise and sport》2013,84(3):311-323

Abstract

The major purposes of the present study were to determine to what extent and in what ways an individual's personality is affected by the working environment. Three questions were asked about the effect of working environment on: (a) realism or accuracy of self-concept, (b) agreement between real self and ideal self, and (c) functionality of personality characteristics. Subjects were 49 physical education faculty in three inner-city and three suburban Los Angeles area high schools. The Holmen Adjective Check List (HACL) was used to assess self-concept, real-ideal self discrepancy, and functionality. Results showed that: (a) suburban teachers had more accurate self-concepts than did inner-city teachers, (b) suburban teachers were seen as being more like their “ideal selves” than were inner-city teachers, and (c) individuals experienced in a given work setting were not necessarily seen as better adapted to that environment than those not working there.  相似文献   

跳远助跑准确性教法的研究     

巢晓春 《安徽体育科技》2013,34(4):83-86

跳远的完整技术包括助跑、起跳、腾空和落地4个连续的动作过程。4个环节中,无论哪个环节出现问题都会影响到跳远的成绩。研究影响助跑准确性的因素,探讨如何提高助跑准确性的教学方法。在教学中,着重强调跳远助跑准确性方法的教学,是提高跳远成绩的关键所在,从而使学生在短期内熟练掌握正确的助跑技术,并且能取得一定的效果。  相似文献   

Technical Reliability Assessment of the Actigraph GT1M Accelerometer     

Pedro Silva  Jorge Mota  Dale Esliger  Gregory Welk 《Measurement in physical education and exercise science》2013,17(2):79-91

The purpose of this study was to determine the reliability of the Actigraph GT1M (Pensacola, FL, USA) accelerometer activity count and step functions. Fifty GT1M accelerometers were initialized to collect simultaneous acceleration counts and steps data using 15-sec epochs. All reliability testing was completed using a mechanical shaker plate to perform six different test conditions in Experiment 1 and 18 test conditions in Experiment 2. The overall intra- and inter-instrument reliability of the GT1M was CV_intra = 2.9% and CV_inter = 3.5% for counts and CV_intra = 1.1% and CV_inter = 1.2% for steps. No batch effects were evident in the 50 GT1Ms. The Actigraph GT1M accelerometer demonstrated good reliability for measuring both counts and steps. However, the ability of the GT1M to consistently detect acceleration at a given acceleration and frequency condition varied widely. Future studies clarifying the filtering limitations and the threshold necessary to detect the occurrence of movement are warranted.  相似文献   

Validity of an upper-body-mounted accelerometer to measure peak vertical and resultant force during running and change-of-direction tasks     

Daniel W.T. Wundersitz  Kevin J. Netto  Brad Aisbett  Paul B. Gastin 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):403-412

This study assessed the validity of a tri-axial accelerometer worn on the upper body to estimate peak forces during running and change-of-direction tasks. Seventeen participants completed four different running and change-of-direction tasks (0°, 45°, 90°, and 180°; five trials per condition). Peak crania-caudal and resultant acceleration was converted to force and compared against peak force plate ground reaction force (GRF) in two formats (raw and smoothed). The resultant smoothed (10 Hz) and crania-caudal raw (except 180°) accelerometer values were not significantly different to resultant and vertical GRF for all running and change-of-direction tasks, respectively. Resultant accelerometer measures showed no to strong significant correlations (r = 0.00–0.76) and moderate to large measurement errors (coefficient of variation [CV] = 11.7–23.9%). Crania-caudal accelerometer measures showed small to moderate correlations (r = ? 0.26 to 0.39) and moderate to large measurement errors (CV = 15.0–20.6%). Accelerometers, within integrated micro-technology tracking devices and worn on the upper body, can provide a relative measure of peak impact force experienced during running and two change-of-direction tasks (45° and 90°) provided that resultant smoothed values are used.  相似文献   

工程监理的信息经济学分析     

廖萍萍  林丹 《福建师范大学学报(哲学社会科学版)》2005,(4):25-28

本文关注监理双重角色和开发商主动披露信息自发需求不足的问题,并从信息经济学的角度,对监理市场的供求进行分析.指出监理质量提高的关键是提高P或收窄P1 ＞P＞P2的区域,即与开发商是否利用信息不对称盈利有关;各种监管力度无法充分反映建筑物最终用户的需求时,P只可能在P2附近摆动,监理市场帕累托改进就无法实现.  相似文献   

试论人文素质教育在“两课”教学中的功能     

陈海宁 《黑龙江高教研究》2002,(5):96-98

“两课”与人科学课程有着密切的联系。人素质是“两课”教学的基础。一些高校的“两课”教学效果不佳,与忽视人素质教育在“两课”教学中的功能有很大关系。本对人素质教育在“两课”教学中的基础作用与功能以及强化人素质教育在“两课”教学中的功能的途径进行了探讨。  相似文献   

经典力学的剖析与发展     

师教民 《石家庄职业技术学院学报》2002,14(2):1-5

论证了惯性质量，引力质量，惯性参照系，惯性力的不合理必，确定了物质质量的概念，统一了惯性参数照系和非惯性参照系，否定了力的绝对性，引出了加速相对性原理和力相对性原理，提出了相对力，相对加速度，相对参照系和绝对力，绝对加速度，绝对参照系的新概念，建立起初步绝对相对论力学。  相似文献   

职业教育调动学生学习积极性的思考     

王莉 《武汉工程职业技术学院学报》2020,(1):103-105

学习动机是直接推动学生进行学习的一种内部动力。学生学习积极性的形成与学习动机的激发有着内在的联系。学习动机的激发是形成学生学习积极性的内在因素,学习发生的深层次根源来自主体的认知需要,然而学习的实际发生则常常需要来自外部环境的刺激。就是说从根本上缺乏认知内需,学习无法发生,但是没有外部环境的刺激,学习上也难以自发启动。尤其是对于职业院校学生来说,其学习动机更需要依靠教师去激发和调动。在实际工作中,要同时发挥内外两种动机的作用,抓住一切机会,提高学生主动参与性,激发、调动学生学习的积极性,帮助学生进行有效学习。  相似文献   

平面连杆机构运动线图的绘制方法     

鲁春发 《十堰职业技术学院学报》2005,18(4):78-79

推导出曲柄摇杆机构和曲柄滑块机构中C点的坐标方程,用应用软件Excel计算出该点在运动过程中的一系列坐标值及坐标值的微变值速度和速度的微变值加速度,并采用Excel中的“插入图表”功能自动绘出了该点的运动线图,为我们在对机构进行运动分析时提供了一个准确、简捷、实用的工具。  相似文献