基于足底压力的羽毛球运动足部受力特征研究

分析羽毛球常用步法的足底压力特征,为减少羽毛球运动中下肢损伤(特别是足部损伤)提供建议,并希望成为羽毛球鞋具设计的依据。利用足底压力测试系统对高水平羽毛球运动员左前场蹬跨步、右前场蹬跨步、一步蹬转起跳等常用步法动作进行测试。结果发现3种步法在离地阶段,足前区的内侧跖骨区以及大拇趾和第1、2跖骨区的最大压力均高于其他部位(P<0.05);着地阶段,蹬跨步是把足底压力集中于脚后跟和足外侧进行缓冲制动,蹬转起跳步则把压力集中于大拇趾以及第1、2跖骨区(P<0.05)。由此可见,羽毛球运动员应注意在采用不同步法时,足前区和足跟区中部及足外侧的负荷变化,并尽可能地选择穿着能够分散上述区域压力的专项鞋来避免足部受力的过度集中。     

运动鞋对羽毛球典型步法中跖趾关节和后足稳定性的影响

以优秀男子羽毛球运动员为研究对象,以最常用的前场蹬跨步法为例,重点运用现代生物力学技术分析了蹬伸(前足屈曲)和着地(稳定)动作的生物力学特性,就不同运动鞋与裸足运动时的生物力学特征进行了对比,探讨了运动鞋对羽毛球运动员下肢生物力学特征的影响及其可能机制.研究发现,对羽毛球运动而言,跖趾关节在足部功能具有一定的重要性;着鞋相对于裸足而言应该更有利于跖趾关节背屈,进而提高蹬地效果;羽毛球运动蹬跨步法着地时不同着鞋状态均呈现一定程度的后足外翻;利用鞋可以有效控制足后部的外翻,进而降低因过度外翻而造成的肌腱、肌肉、韧带的过度负荷,保护下肢免于受到伤害;判断鞋是否确实存在提高后足运动活动度以足够缓冲地面冲击负荷的关键就在于外翻过度的"度"确切为多少.在上述研究基础上,从前足屈曲和后足稳定等几个角度探讨了羽毛球运动下肢生物力学特征对运动鞋研发的启示,认为羽毛球专用鞋应具有适当屈曲刚度,既不会改变足的易屈曲性,也不会额外增加足部负担以克服鞋刚度进行屈曲,又能够辅助提高蹬地效率,增强足部"扒地"效果;羽毛球专用鞋应能有效控制足后部的外翻运动,进而降低因过度外翻而造成的肌腱、肌肉、韧带的过度负荷,保护下肢免于受到伤害.     

球星支招

1接杀球时,脚后跟微微抬起Q:以右手持拍为例,在接杀球时,脚后跟是否需要微微抬起?应该是一只脚的后跟抬起(左脚)?还是两只脚后跟都抬?抬脚跟有什么好处?(bestco)A:是的,脚后跟微微抬起是合理的。其实,在大部分动作里,我们都不会把脚站死,而是双脚的脚后跟都微微抬起。就像起动前的小垫步一样,后跟微微抬起有利于更快速起动。     

基于儿童足部发育规律及步态特征的6～10岁童鞋设计原则

结合华南师范大学附小20名女童静、动态足底压力测试数据、穿鞋习惯、消费观念等,从生物力学角度对儿童出现的主要足部不适症状进行分析,指出中国6～10岁童鞋设计应遵循的主要原则:一是与脚的形状相似,成扇形,为足的自然生长发育创造条件;二是儿童走路时鞋子产生弯折的部位符合儿童足的比例,不应只是成人鞋的翻版;三是通过增加足中部及足后跟稳定性的方法达到减小足底压力的目的。并建议小童、中童、大童鞋的划分标准以年龄为依据,而不应以鞋码大小为依据。     

鞋前掌楔形结构对羽毛球前场蹬跨步动作的生物力学影响

目的探讨放置在羽毛球鞋前掌部位的楔形结构对前场蹬跨步动作产生的影响,为提高羽毛球鞋的运动表现及防护羽毛球运动损伤提供参考。方法招募20名高校羽毛球专项学生作为受试者,采用重复性测量的实验设计。实验用鞋为前掌部位放置了2种不同高度楔形结构的羽毛球鞋和作为对照鞋的普通羽毛球鞋。结果楔形结构能够增大前场蹬跨步动作触地阶段的跖趾关节最大背屈角度(P <0. 05)和跖趾关节活动范围(P <0. 05),增加跖趾关节最大蹬伸速度(P <0. 01),增加踝关节最大外翻角度(P <0. 05),降低踝关节最大内翻角度(P <0. 05),能够降低前足受到的侧向力(P <0. 05),增加踝关节的最大外翻力矩(P <0. 05),增大踝关节最大跖屈力矩(P <0. 01)。结论 (1)在运动员完成前场蹬跨步动作的着地阶段,穿着前掌具有楔形结构的羽毛球鞋没有对膝关节运动产生影响,未来研究应关注于楔形结构的高度及材料硬度对膝关节的影响。(2)前掌楔形结构降低了运动员踝关节的稳定性,建议作为训练鞋使用以增加训练效果,但在比赛中应谨慎穿着。(3) 0. 008 m楔形高度羽毛球鞋不仅能够增加前场蹬跨步着地过程中跖趾关节的蹬伸速度,帮助提升运动表现,而且能够降低前足受到的侧向力,改善鞋的缓冲效果,有助于降低羽毛球运动中前足的损伤风险。     

不同外源性生物力学手段对原地纵跳时足底的力学影响

通过采用足部不同外源性生物力学手段，即穿着两种不同防震功效的运动鞋与裸足状态下对原地纵跳时足底压强分布区域特征、MMP(mean maximum pressure)平均最大压强值特征、MVP(mean value pressure)平均压强值特征、纵跳落地缓冲压力值变化的时间差异性、X轴与Y轴向压力的合力特征的比较研究，探究运动鞋的不同防震系统设计在人体进行原地纵跳时，对足底的缓震功效的形成机制，从而指导设计运动鞋，并且在一定程度上加强人们对防震运动鞋的认识。     

高水平女子羽毛球运动员下肢力量特征研究

通过对13名高水平女子羽毛球运动员进行下肢等速肌力测试,以及静态、行走、跑步、起跳、正反手跨弓步共5种运动状态的足底压力分析,发现:女子羽毛球运动员下肢肌群力量双侧较为均衡,髋部内收肌群、屈膝肌群、膝部内旋肌群、踝内旋肌群随运动速度加快而贡献程度不断增加;常速行走时左侧下肢用力自动化过程较敏感,双腿反向纵跳(CMJ)落地时右侧下肢承担了主要的缓冲负荷,单腿CMJ落地时左侧下肢离心负荷较右侧更大;反手区域步法受力高于正手区域,反手区域步法更多是足跟部受力,正手区域步法更多是足前部受力,限制下肢旋内运动的肌群均能影响常见步法的足内侧足底受力。     

体育舞蹈专业女大学生足底压力分布特征研究

目的:探讨分析体育舞蹈专业女大学生足底压力的分布特征,为参加体育舞蹈训练的普通大学生和体育舞蹈专业学生提供数据参考。方法:采用footscan USB足底压力平板测试系统对8名普通女大学生和8名体育舞蹈专业女大学生进行正常行走、伦巴走步的足底压力测试。结果:裸足正常行走过程中,体育舞蹈专业和普通女大学生在足底各分区压力分布基本一致,无显著性差异;普通女大学生在第2-5趾、第1跖骨、第2跖骨、第5跖骨、足中部区域左、右差异有统计学意义,而体育舞蹈专业女大学生除了在第1趾存在差异外,左右足无显著性差异;体育舞蹈专业大学生在伦巴走步过程中,压力中心轨迹与正常行走时有很大差异。这种差异在足底各分区压力-时间积分中表现为,左右脚的脚前掌、足中部压力-时间积分变大,足跟部位压力-时间积分明显变小,且与正常行走相比有显著性差异,做舞蹈动作时,压力主要集中于脚前掌和足弓部位。结论:体育舞蹈专业女大学生在做舞蹈动作时,压力主要集中于脚前掌和足中部,且外侧跖骨受力显著。参加体育舞蹈训练时必须穿着适当高度、适当硬度的舞蹈鞋来缓解脚前掌和足中部的压力。     

排球运动员步态支撑期的足底压力特征

通过测试得到排球运动员步态中足底压力的主要特征,并比较膝关节损伤运动员与无膝关节损伤运动员的足底压力特征,尝试分析膝关节损伤对足底压力产生的变化,为排球运动员正常步态数据提供可信的参考标准。选取北京体育大学竞技体育学院排球专项学生共48人(26男、22女)作为研究对象。运用FOOTSCAN足底压力分布测量系统和QUALISYS-MCU500红外运动测试系统的6个摄像头采集足底压力及步态基本运动学参数,测量被试者赤足状态下的步态。要求被试者以自己正常的步速行走,左右脚分别测试3次。将足部分为10个解剖分区:第L趾骨(T1)、第2-5趾骨(T2-T5)、第1跖骨(M1)、第2跖骨(M2)、第3跖骨(M3)、第4跖骨(M4)、第5跖骨(M5)、足中部(MF)、足跟内侧(HM)和足跟外侧(HL)。选取各个分区的接触开始时刻、接触结束时刻、最大压强时刻、接触时间作为时间指标。根据足底压力数据,男女排球运动员在步态支撑时期不同阶段的比例分别为:着地阶段(6.2%男,6.4%女)、前足接触阶段(5.5%男,6.6%女)、整足接触阶段(43.44%男,40.4%女)、离地阶段(42.9%男,46.5%女)。膝关节损伤运动员受伤腿足中部足底压强峰值明显低于未受伤腿。     

辽宁男排运动员扣球起跳技术足底压力特征研究

运用测力鞋垫系统,对辽宁男排运动员扣球起跳技术进行了测试,探索排球扣球起跳技术的足底力学特征,为提高排球运动员扣球起跳高度和下肢专项力量训练提供理论依据和指导.研究结果表明,右足的贡献大于左足.右腿有一个明显的支撑—缓冲—蹬伸的过程.右足各区域的着地时序是足后区—足中区—足前区,左足各区域几乎是同时着地.蹬伸阶段左、右足均有外翻现象.     

Confirmatory factor analysis of the Competitive State Anxiety Inventory-2.

The aim of this study was to evaluate the factor structure of the Competitive State Anxiety Inventory-2 (CSAI-2) using confirmatory factor analysis. Volunteer participants (n = 1213) completed the CSAI-2 approximately 1 h before competition and the data were analysed in two samples. The hypothesized model showed poor fit indices in both samples independently (Robust Comparative Fit Index: sample A = 0.82, sample B = 0.84) and simultaneously (Comparative Fit Index = 0.83), suggesting that the factor structure proposed by Martens et al. is flawed. Our findings suggest that a limitation of the Cognitive Anxiety scale derives from phrasing items around the word 'concerned' rather than 'worried'. We suggest that being concerned about an impending performance does not necessarily mean that an athlete is experiencing negative thoughts, but that the athlete is acknowledging the importance and difficulty of the challenge and is attempting to mobilize resources to cope. The present results question the use of the CSAI-2 as a valid measure of competitive state anxiety.     

递增负重蹲跳与提踵时小腿三头肌表面肌电图信号比较

目的:通过对男大学生小腿三头肌在递增负重提踵和蹲跳动作时表面肌电(sEMG)信号的分析,探讨动作形式与神经肌肉活动方式之间的联系。方法:男大学生在不负重和30%、60%、80%、100%最大力量(1RM)负重下分别进行一次提踵和蹲跳动作,同时记录腓肠肌内侧头(GM)、外侧头(GL)和比目鱼肌(SO)向心收缩阶段的sEMG信号,比较各等级负重条件下两种动作运动时iEMG、MF和MPF等肌电指标的变化。结果:在进行负重提踵时,随着重量增加,GM、GL和SO表面肌电的iEMG均显著增加,但MF和MPF在不同负重等级完成动作时的差异不显著;在进行负重蹲跳时,各肌肉表面肌电信号的iEMG、MF和MPF在各级负重之间具有显著差异,其数值与重量的增加具有线性关系;在不负重提踵时各肌肉的iEMG值与蹲跳差异不显著,但大负重后显著高于蹲跳;MF和MPF值在不负重提踵时显著高于蹲跳,负重后其差异基本不显著。结论:在递增负重提踵和蹲跳动作时,小腿三头肌向心收缩阶段的sEMG信号表现存在差异,其所反映的神经肌肉控制方式不同,提示所完成动作的动力学特性如速度、多关节链等,可能会影响运动单位募集的方式。     

田径运动员趾骨形态与跳深实验中支撑时间关系的研究

目的：从运动员选材角度探讨趾骨形态与跳深实验中支撑时间关系,为田径运动员趾骨形态选材提供参考。方法：对84名上海市一二线运动员进行身高、体重、足底形态、跳深实验测试,记录其趾骨长度、趾骨整齐性、脚与地面支撑时间等指标。分别以趾骨长短(趾骨短组和趾骨长组)、趾骨整齐性(整齐性高组和整齐性低组)、运动员等级(优秀组和一般组)进行分组,研究趾骨形态与跳深实验中支撑时间关系。结果：男、女均表现出第一趾骨短组的支撑时间小于第一趾骨长组,趾骨整齐性高组支撑时间小于整齐低组,男子第二趾骨长组的支撑时间小于第二趾骨短组。结论：第一趾骨短,5趾骨整齐性好,特别是前3个趾骨整齐性好,有利于缩短跑跳过程中脚与地面的支撑时间。     

试析影响竞走裁判员准确判罚的客观因素

竞走比赛中多种客观因素对裁判员准确判罚的影响是客观存在的现实。裁判员对判罚尺度的掌握及对各种技术的认同，将对竞走运动的发展及对运动员的成长产生巨大的影响。     

Measuring the effectiveness of offensive match-play in professional soccer

Abstract

The broader measures of offensive effectiveness, such as scoring opportunities and shots at goal, are commonly used as an alternative to goals scored due to the naturally low probability of scoring (about 1%) in soccer match-play. These measures may enable soccer practitioners to objectively see behind single match results, which are often influenced by chance. The purpose of this study was to examine the relationship between broader measures (scoring opportunities and score box possessions) and the ultimate measure (goals scored) of offensive effectiveness. We analysed data from videotapes of 163 of 182 (90%) matches played in the Norwegian men's professional league during the 2004 season. Multiple logistic regression analyses showed very similar results when comparing the effectiveness of different offensive tactics, regardless of which outcome was used. For example, counterattacks were more effective than elaborate attacks in producing goals (odds ratio OR=2.07, 95% confidence interval: 1.40 to 3.05), scoring opportunities (OR=2.30, 95% confidence interval: 1.28 to 4.15), and score box possessions (OR=2.12, 95% confidence interval: 1.39 to 3.25). The receiver-operating characteristic function statistical procedure was used to examine the association between each of the three measures of offensive effectiveness: scoring opportunities, score box possessions, and goals scored. No significant difference was observed between the area under the curve (AUC) for the broader measures (scoring opportunities and score box possessions) and the ultimate measure (goals scored) of offensive effectiveness. The 95% confidence interval of the AUC for both scoring opportunities (0.74–0.84) and score box possessions (0.68–0.76) includes the AUC for goals scored (0.74). Thus, the results are very similar regardless of which outcome measure for offensive effectiveness is used. This indicates that scoring opportunities and score box possessions (shooting opportunities) can be used as a proxy for goals scored when comparing the effectiveness of different playing tactics in soccer. Compared with goals scored, using scoring opportunities or score box possessions requires smaller match samples for meaningful analyses, and may therefore be more feasible alternatives.     

Determining Intensity Levels of Selected Wii Fit Activities in College Aged Individuals

The purpose of this study was to determine the intensity of Nintendo Wii Fit games using indirect calorimetry. Twenty-five college students completed Wii Fit activity sessions at two difficulty levels within aerobics, strength, and yoga categories. Resting metabolic rate and exercise oxygen uptake were measured, and metabolic equivalents were calculated. Measured metabolic equivalents and calculated metabolic equivalents ranged from 2.30 ± .42 and 2.44 ± .38 for Yoga to 5.73 ± 1.36 and 6.04 ± 1.09 for aerobics, respectively. All selected Wii Fit activity intensities were significantly higher than resting, p < .001; aerobic and strength activities met the moderate intensity threshold (three metabolic equivalents, p < .001), while yoga activities did not (p < .005). Aerobic and yoga activities of medium difficulty were more intense than the corresponding easy-rated activities (p < .005). There were no statistical differences between measured and calculated metabolic equivalents. Wii Fit has potential as an effective tool for helping college-aged individuals increase their physical activity.     

Confirmatory factor analysis of the Competitive State Anxiety Inventory-2

The aim of this study was to evaluate the factor structure ofthe Competitive State Anxiety Inventory-2 (CSAI-2) using confirmatory factor analysis. Volunteer participants (n= 1213) completed the CSAI-2 approximately 1 h before competition and the data were analysed in two samples. The hypothesized model showed poor fit indices in both samples independently (Robust Comparative Fit Index: sample A=0.82, sample B =0.84) and simultaneously (Comparative FitIndex = 0.83), suggesting that the factor structure proposed by Martens et al. is flawed. Our findings suggest that a limitation of the Cognitive Anxiety scale derives from phrasing items around the word ‘concerned’ rather than ‘worried’. We suggest that being concerned about an impending performance does not necessarily mean that an athlete is experiencing negative thoughts, but that the athlete is acknowledging the importance and difficulty of the challenge and is attempting to mobilize resources to cope. The present results question the use of the CSAI-2 as a valid measure of competitive state anxiety.     

Figure Skating

The purpose of this study was to compare triple (T) and quadruple (Q) toe‐loop figure skating jumps and quantify basic characteristics of these jumps to provide information to coaches that will assist them in teaching quadruple toe‐loops to elite figure skaters. High‐speed video was taken during men's practice and competition sessions at the 2002 Salt Lake City Winter Olympics; three‐dimensional analyses of selected triple and quadruple jumps were completed. The most significant difference between triple and quadruple toe‐loops was an increase in rotational velocity in the air. Additionally, increased vertical velocity at take‐off and subsequent time in the air were also observed. Three main conclusions were developed: 1) The timing of rotation of the hips and shoulders was different for quadruple toe‐loops compared to triples with the differences being observed before toe‐pick; 2) Increases in rotational velocity occurred primarily as a result of the skaters assuming different body positions from take‐off through landing which resulted in tighter rotating positions for longer durations of the jump; 3) Greater vertical velocity was gained during the propulsive phase due to the extension of the legs during the press off the ice.     

我国优秀男子拳击运动员后手直拳击打环节相关肌群的EMG特征及其运动学分析

目的:研究我国优秀男子拳击运动员后手直拳出拳击打环节相关肌群的sEMG特征及其相应的运动学变化,为拳击专项力量训练提供参考.方法:通过表面肌电和三维红外高速摄像系统同步测试方法,采集6名高水平男子拳击运动员后手直拳出拳击打环节表面肌电和运动学的相关数据.结果:1)出拳击打环节,肌肉活动顺序为:腓肠肌→股二头肌→三角肌前束→肱三头肌→肱二头肌长头→肱桡肌.2)击打过程中三角肌前束、肱二头肌和肱三头肌肉在相应时间位置上出现明显的预激活和共收缩现象.3)肌肉做功百分比排序为:三角肌前束＞肱三头肌＞股二头肌＞腓肠肌＞肱桡肌＞肱二头肌长头,aEMG计算结果与肌肉做功百分比保持相一致的趋势.4)肩关节、上臂环节质心和拳心速度的峰值在击打过程中呈现次序性.结论:拳击后直拳出拳击打环节所选肌肉活动呈现从下肢向上肢激活的次序性.击打过程中三角肌前束、肱二头肌和肱三头肌肉在相应时间位置上出现的预激活和共收缩现象可能是反映运动员技术水平和特点的指标.在肌肉做功百分比和aEMG方面,三角肌前束、肱三头肌和股二头肌在动作过程中表现出相对重要的地位.上肢相关肌群的活动次序与肩关节、上臂环节质心和拳心速度变化的时序性有着合理的解剖学相关,是产生上肢开放链鞭打动作的根本原因.     

运动员意志品质量表的编制

通过查阅资料总结前人的研究方法和经验,提出关于运动员意志品质结构的8个维度:目的性、独立性、果断性、勇敢性、坚韧性、自制性、自觉性、自信心。此次研究的主要任务是编制适用于测量所有运动员意志品质的量表,对初编114个条目经过测验分析,筛选出56个项目。研究结果:(1)分量表和总量表的重测信度达到显著性水平;分量表和总量表的内部一致性比较理想,DLX、YGX量表有点偏低。(2)各分量表之间的独立性比相关性高;分量表与总量表之间的相关性较高;同时效度良好。(3)采用验证性因素分析抽取8个因子能够独立的解释量表的8个维度。