Frequency content asymmetry of the isokinetic curve between ACL deficient and healthy knee
Frequency content asymmetry of the isokinetic curve between ACL deficient and healthy knee
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DOI：
10.1016/j.jbiomech.2003.11.009
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发表时间：
2004-06-01
影响因子：
2.4
通讯作者：
Georgoulis, A
中科院分区：
文献类型：
--
作者：
Tsepis, E;Giakas, G;Georgoulis, A
前交叉韧带（ACL）缺陷患者同心等速膝关节伸展的扭矩-时间曲线模式通常呈现与胫骨前平移水平相关的中等范围不规则性。本研究的目的是比较ACL缺陷和健康膝关节之间等速扭矩产生的平滑性。30名ACL缺陷的足球运动员在Biodex测力计上以60 °/s的速度进行了双侧最大同心膝关节伸展-屈曲试验。保留三个中间试验（共六条曲线），并提交进一步的数据处理。计算每条伸展和屈曲曲线的信号功率90%、95%和99%水平内的最大频率值。ACL缺陷侧的频率内容被证明是统计学上高于完整侧在所有水平的功率谱。对于相应的功率水平，膝关节伸展的频率含量的百分比差异分别为18.8%、10.6%和40.0%，膝关节屈曲的频率含量的百分比差异分别为49.5%、24.5%和16.3%。这表明更高的振荡，因此，受伤的膝盖更不稳定的机械输出。对本研究结果的总体生物学解释是基于这样的概念，即受干扰的运动通常与关节功能水平差有关。(C)2003 Elsevier Ltd.保留所有权利。
The torque-time curve patterns of concentric isokinetic knee extension in anterior cruciate ligament (ACL) deficient patients usually present mid-range irregularities associated with the level of anterior tibial translation. The purpose of this study was to compare the smoothness in isokinetic torque production between the ACL deficient and the healthy knee. Thirty ACL deficient soccer players performed bilaterally five trials of maximum concentric knee extension-flexion at 60degrees/s on a Biodex dynamometer. The three middle trials (a total of six curves) were retained and submitted to further data processing. Maximum frequency values contained within the 90%, 95% and 99% level of the signal power were calculated for each extension and flexion curve. The frequency content of the ACL deficient side proved to be statistically higher compared to the intact side at all levels of the power spectrum. The percentage differences in the frequency content were 18.8%, 10.6% and 40.0% for knee extension, and 49.5%, 24.5% and 16.3% for knee flexion, for the respective power levels. This indicated higher oscillations and, therefore, more unstable mechanical output of the injured knee. An overall biological interpretation of the present results is based on the notion that disturbed motion is generally connected to poor level of joint functionality. (C) 2003 Elsevier Ltd. All rights reserved.