Human Performance Laboratory, University of Calgary, Alberta, Canada.
J Electromyogr Kinesiol. 2010 Aug;20(4):676-83. doi: 10.1016/j.jelekin.2009.11.005. Epub 2009 Dec 11.
The study compares the timing and frequency changes of surface EMGs recorded from osteoarthritis patients with previous traumatic ankle injury and normal subjects during level walking. EMG intensity (power) was obtained by a wavelet analysis. There were intensity values for each frequency characterized by the wavelets for every time point. The intensities were compounded into Multi Muscle Patterns (MMP) simultaneously showing the time and spectral aspects of the lower leg muscle activity. The aim of the study was to test the hypothesis that the differences between the group of the MMPs from the affected leg (AFL) and the not affected leg (NAL) allow detecting whether a newly measured MMP results from an AFL or NAL. This hypothesis was tested by a spherical classification procedure yielding the correctly classified MMPs thus indicating the significance of the differences between the MMPs of the AFL and NAL. The hypothesis was supported (not falsified) by the results. Thus there were common features of muscle activity in the AFL of most osteoarthritis patients that allowed detecting whether the MMP of a new patient was of the kind seen in most other osteoarthritis patients. The spectral, timing and intensity factors in the MMP that allowed this classification were visualized in the mean MMPs of the patients and the control group. The comparison revealed where on average the relative timing and spectral differences of the muscle activation of osteoarthritis patients and control subjects occurred.
本研究比较了既往创伤性踝关节损伤的骨关节炎患者和正常受试者在水平行走时表面肌电图（EMG）的时间和频率变化。EMG 强度（功率）通过小波分析获得。每个频率都有特征强度值，由每个时间点的小波表示。强度被复合成多肌肉模式（MMP），同时显示小腿肌肉活动的时间和频谱方面。本研究的目的是检验以下假设：受影响腿（AFL）和未受影响腿（NAL）的 MMP 之间的差异可以检测到新测量的 MMP 是来自 AFL 还是 NAL。通过球形分类程序检验了这一假设，该程序产生了正确分类的 MMP，从而表明 AFL 和 NAL 的 MMP 之间的差异具有显著性。结果支持（而非证伪）了这一假设。因此，大多数骨关节炎患者的 AFL 具有共同的肌肉活动特征，这使得能够检测新患者的 MMP 是否属于大多数其他骨关节炎患者所见到的类型。允许进行这种分类的 MMP 的频谱、定时和强度因素在患者和对照组的平均 MMP 中可视化。比较揭示了骨关节炎患者和对照组的肌肉激活的相对定时和频谱差异平均发生在哪里。
