Skating mechanics of change-of-direction manoeuvres in ice hockey players

Ice hockey requires rapid transitions between skating trajectories to effectively navigate about the ice surface. Player performance relates in large part to effective change-of-direction manoeuvres, but little is known about how those skills are performed mechanically and the effect of equipment design on them. The purpose of this study was to observe the kinetics involved in those manoeuvres as well as to compare whether kinetic differences may result between two skate models of varying ankle mobility. Eight subjects with competitive ice hockey playing experience performed rapid lateral (90°) left and right change-of-direction manoeuvres. Kinetic data were collected using force strain gauge transducers on the blade holders of the skates. Significantly greater forces were applied by the outside skate (50–70% body weight, %BW) in comparison to the inside skate (12–24%BW, p < 0.05). Skate model and turn direction had no main effect, though significant mixed interactions between leg side (inside/outside) with skate model or turn direction (p < 0.05) were observed, with a trend for left-turn dominance. This study demonstrates the asymmetric dynamic behaviour inherent in skating change-of-direction tasks.     

不同齿轮比训练时自行车运动员肌电图的研究

探讨利用sEMG对自行车运动员运动肌组织进行监测与机能分析的可行性。方法:8名自行车运动员进行42/15、52/12与52/15齿轮比练习台骑行测试,采用芬兰Muscle Tester ME3000P8肌电图仪与MegaWin软件系统记录分析运动时的sEMG值。结果表明:同侧同部位肌组织不同齿轮比练习时IEMG/s值不同,除小腿三头肌(P<0.05)外,各部位IEMG/s组间无显著差异;相同训练条件下同部位肌组织左右腿IEMG/s个体差异明显,提示sEMG能够直观反映动力性运动中肌肉的收缩活动,不同齿轮比骑行对下肢不同部位骨骼肌刺激不同。建议:训练监控中,sEMG适合应用于运动员个体的纵向比较。     

积分肌电对青年男子股四头肌的疲劳评价

对30名青年男子按不同负荷进行下肢运动至疲劳的肌电图进行全程监测,通过对不同阶段IEMG进行分析处理,旨在探讨利用表面肌电图对受训肌肉进行监测和机能分析的可行性。结果发现,在使用IEMG,变化比例评定负荷程度和疲劳状态时应以运动初期肌电达到稳定状态的结果为基础。在双侧肌肉同时进行力量练习时,若着重发展弱势腿力量应采用中小训练强度,而采用大强度的训练刺激增加优势腿力量。     

表面肌电图技术在体育科研中的应用

表面肌电图是从肌肉表面通过电极引导,记录神经肌肉系统活动时的一维时间序列信号。表面肌电图作为一种无创伤检测方法,其信号的检测分析在临床诊断、康复医学及运动医学中具有重要意义。文单主要对表面肌电图技术在国内外体育科研领域中的应用研究现状做一综述。     

黄旭双杠支撑屈体后空翻2周成挂臂动作的运动学分析

通过运动学分析揭示了我国优秀运动员黄旭完成的双杠支撑屈体后空翻2周成挂臂动作的运动学规律和技术特点，为我国运动员发展和改进该类动作提供理论依据和技术参数。     

激励与量化目标在普通高校排球教学中的实验分析

运用不断激励和量化教学目标的方法进行排球教学实验,结果表明,该教学模式能创造富有信心、充满动力的氛围完成较大的练习负荷,能提高学生互助、相互激励的精神,提高学生学习排球的兴趣和信心,增强学生的耐力素质和心理素质,提高排球教学的效益。     

sEMG信号分析及其应用研究进展

表面肌电信号是从肌肉表面通过电极引导,记录下来的神经肌肉系统活动时的一维时间序列信号,其变化与参与活动的运动单位数量,运动单位活动模式和代谢状态等因素有关,能够实时地,准确地和在非损伤状态下反映肌肉活动状态和功能状态。本文拟就ｓＥＭＧ信号分析及其应用研究进展进行系统回顾。     

Influence of bench angle on upper extremity muscular activation during bench press exercise

This study compared the muscular activation of the pectoralis major, anterior deltoid and triceps brachii during a free-weight barbell bench press performed at 0°, 30°, 45° and –15° bench angles. Fourteen healthy resistance trained males (age 21.4 ± 0.4 years) participated in this study. One set of six repetitions for each bench press conditions at 65% one repetition maximum were performed. Surface electromyography (sEMG) was utilised to examine the muscular activation of the selected muscles during the eccentric and concentric phases. In addition, each phase was subdivided into 25% contraction durations, resulting in four separate time points for comparison between bench conditions. The sEMG of upper pectoralis displayed no difference during any of the bench conditions when examining the complete concentric contraction, however differences during 26–50% contraction duration were found for both the 30° [122.5 ± 10.1% maximal voluntary isometric contraction (MVIC)] and 45° (124 ± 9.1% MVIC) bench condition, resulting in greater sEMG compared to horizontal (98.2 ± 5.4% MVIC) and –15 (96.1 ± 5.5% MVIC). The sEMG of lower pectoralis was greater during –15° (100.4 ± 5.7% MVIC), 30° (86.6 ± 4.8% MVIC) and horizontal (100.1 ± 5.2% MVIC) bench conditions compared to the 45° (71.9 ± 4.5% MVIC) for the whole concentric contraction. The results of this study support the use of a horizontal bench to achieve muscular activation of both the upper and lower heads of the pectoralis. However, a bench incline angle of 30° or 45° resulted in greater muscular activation during certain time points, suggesting that it is important to consider how muscular activation is affected at various time points when selecting bench press exercises.     

表面肌电分析在速度滑冰中的应用

速度滑冰是黑龙江省传统优势项目,是全运会冬季项目的夺金点。丰富科研监控手段,提高训练科学化水平对提高速滑运动员比赛成绩起着至关重要的作用。通过文献综述法阐述表面肌电技术的基本原理,总结其信号分析在速度滑冰训练监控、评价运动性疲劳和运动康复领域的应用特点。结果表明,表面肌电技术因其评价手段的多样性、合理性和准确性等优势,势必将成为体育科研的重要手段．在璩度滑冰的科研领域有着广泛的应用前景。     

sEMG技术在评价运动性疲劳方面的方法及应用

通过文献综述法简要总结了表面肌电技术的原理特点和影响因素,介绍了表面肌电图评价疲劳的机理和主要研究方法,并对这项技术在评价疲劳领域的前景进行展望.结果说明,表面肌电技术因其评价手段的多样性、评价结果的准确性以及安全无创的操作性等诸多优势,势必将成为监控运动性疲劳的重要手段,在体育科研领域有着广泛的应用前景.