Preparation time influences ankle and knee joint control during dynamic change of direction movements

The influence of preparation time on ankle joint biomechanics during highly dynamic movements is largely unknown. The aim of this study was to evaluate the impact of limited preparation time on ankle joint loading during highly dynamic run-and-cut movements. Thirteen male basketball players performed 45°-sidestep-cutting and 180°-turning manoeuvres in reaction to light signals which appeared during the approach run. Both movements were executed under (1) an easy condition, in which the light signal appeared very early, (2) a medium condition and (3) a hard condition with very little time to prepare the movements. Maximum ankle inversion angles, moments and velocities during ground contact, as well as EMG signals of three lower extremity muscles, were analysed. In 180°-turning movements, reduced preparation time led to significantly increased maximum ankle inversion velocities. Muscular activation levels, however, did not change. Increased inversion velocities, without accompanying changes in muscular activation, may have the potential to destabilise the ankle joint when less preparation time is available. This may result in a higher injury risk during turning movements and should therefore be considered in ankle injury research and the aetiology of ankle sprains.     

单侧功能性踝关节不稳者单腿下落过程的生物力学研究

目的:研究功能性踝关节不稳者患侧与健侧单腿下落生物力学特征的差异性。方法:采用Vicon红外高速摄像系统和Kistler三维测力台对15名单侧功能性踝关节不稳者分别进行患侧与健侧40 cm高的单腿下落实验测试,采集下落过程中触地侧下肢的地面反作用力及运动学数据,用配对t检验分析两侧间的差异性,检验水准选α=0.05。结果:在触地前100 ms时及触地时膝踝的瞬时角度、落地稳定时间、落地稳定末的踝关节角度、膝前馈的角度变化量以及内外侧方向GRF峰值对应时间的比较中,两侧间差异存在统计学意义。结论:单侧FAI者患侧单腿下落触地后各方向地面反作用力峰值相对比健侧单腿下落时小,各方向地面反作用力峰值的出现时间相对晚于健侧;同时还发现单侧FAI者在下落过程中可能存在前馈神经肌肉控制的改变。     

我国高水平健美操运动员踝关节损伤的致因分析

对造成我国高水平健美操运动员踝关节损伤的原因进行调查与分析,目的是为了保证健美操运动训练能顺利的进行,在比赛中取得优异成绩,同时也为健美操训练与比赛在防止踝关节损伤的发生提供参考依据。     

大学体育院系普修跨栏跑教学中踝部损伤的原因及预防

本文通过调查大学体育院系普修跨栏跑运动中,踝部发生损伤的机率及其损伤发生的阶段。从踝部的解剖结构特点,分析踝部运动损伤的原因,从中找出规律,并针对原因提出一些预防的方法,为教师在跨栏跑教学训练中减少学生踝部运动损伤提供理论依据。     

青少年短跑运动员膝踝部损伤与安全防范对策

对27名短距离跑跳田径运动员进行为期1年的医务监督和伤病诊治，并作病例分析。发现，在118例损伤中，膝踝部损伤占46．61％。损伤还涉及肌腱及其附属组织、韧带、肌筋膜、软骨等结构。90％以上为轻度损伤，患病率无显著性性别异。85．45％的膝、踝部损伤发生在身体训练和专项辅助训练中。认为，青少年田径运动员的膝、踝部损伤，总体上是身体条件与训练不相适应的结果。某侧肢体的损伤与不同专项技术特点中度相关，高强度训练比大运动量训练更能导致慢性损伤的发生和加重。对技术动作与训练、训练密度与节奏、训练计划与安排做出安全评价与监督，这对于处于成长期的青少年运动员是尤其重要的。     

牵引复位法治疗运动员踝关节扭伤的疗效分析

运用牵引复位法治疗运动员踝关节扭伤100例,获得满意效果。本文介绍了复位手法,并对该症的解剖特点,病因,手法作用机理及现场救护应注意的总是进行了讨论．     

国产气垫夹板治疗踝关节损伤的临床观察

运用国产气垫夹板对37例急性踝关节损伤进行了治疗效果的观察和分析。结果证实:国产气垫夹板对踝关节扭伤后所致的韧带损伤和稳定性骨折均有明显的治疗作用;踝关节气垫夹板固定时间相对较短,韧带拉伤平均18天,稳定性骨折平均31天;国产气垫夹板限制踝关节内翻和外翻,但不影响踝关节的背伸和跖屈运动,患者可进行早期关节活动。     

Effects of changing speed on knee and ankle joint load during walking and running

Joint moments can be used as an indicator of joint loading and have potential application for sports performance and injury prevention. The effects of changing walking and running speeds on joint moments for the different planes of motion still are debatable. Here, we compared knee and ankle moments during walking and running at different speeds. Data were collected from 11 recreational male runners to determine knee and ankle joint moments during different conditions. Conditions include walking at a comfortable speed (self-selected pacing), fast walking (fastest speed possible), slow running (speed corresponding to 30% slower than running) and running (at 4 m · s^?1 ± 10%). A different joint moment pattern was observed between walking and running. We observed a general increase in joint load for sagittal and frontal planes as speed increased, while the effects of speed were not clear in the transverse plane moments. Although differences tend to be more pronounced when gait changed from walking to running, the peak moments, in general, increased when speed increased from comfortable walking to fast walking and from slow running to running mainly in the sagittal and frontal planes. Knee flexion moment was higher in walking than in running due to larger knee extension. Results suggest caution when recommending walking over running in an attempt to reduce knee joint loading. The different effects of speed increments during walking and running should be considered with regard to the prevention of injuries and for rehabilitation purposes.     

大学生步态特点与踝关节等动肌力的相关性研究

运用Cybex-NORM等速肌力测试系统,RSscan足底压力板测试系统对27名在校大学生（男15名,女12名）进行步向角测试,30°/s,120°/s两种角速度踝关节内收、外展的等动肌力测试,旨在探讨大学生步态特点及内、外八字形成的肌力学机制.研究结果：（1）大学生青年步向角的正常范围为1～15°;（2）男性步向角均值约为11.4°,女性步向角均值约为4.7°,男女性别差异具显著性;（3）角速度为30°/s和120°/s的内收、外展峰力矩,内收、外展平均力矩以及外展内收力矩比值均显示男性大于女性,且有显著性差异;（4）踝关节外展、内收肌力并非随着步向角的增大而增大或减小,内、外八字步态踝关节外展、内收肌力均小于正常步态;（5）30°/s和120°/s两种速度下,3种步态的踝关节外展内收肌力比都几近相等,没有显著性差异.结论：（1）23岁左右青年大学生步向角的正常范围为1～15°,小于1°为内八字步态,大于15°为外八字步态;（2）步向角、踝关节外展、内收肌力矩,外展内收肌力比均存在性别差异;（3）内、外八字不良步态形成的肌力学原因是踝关节外展、内收肌力同时薄弱,而不是外展内收肌力发展失衡,深层原因需要进一步深入探讨和研究.