Department of Physical Therapy, Creighton University, 2500 California Plaza, Omaha, USA.
J Electromyogr Kinesiol. 1994;4(1):47-59. doi: 10.1016/1050-6411(94)90026-4.
Normalization of electromyographic (EMG) data has been described in the scientific literature as crucial for comparisons between subjects and between muscles. The reference value used in the normalization equation has, however, varied across reports. Comparison between studies could be facilitated by use of a common value. We propose the best way to select the common value is through a reliability approach. Accordingly, the purpose of this study was to identify which of three EMG normalization values provided the most reproducible data set. The gastrocnemius EMG results from 20 normal persons and 20 individuals with anterior cruciate deficiency who were participating in a larger study were normalized to a maximum voluntary isometric contraction (MVIC) EMG, peak dynamic EMG, and mean dynamic EMG. Values were then subjected to evaluation using four statistical measures: inter and intrasubject coefficients of variation (CV), variance ratio (VR), and intraclass correlation coefficient (ICC). The CV measures, while not being reflective of reliability were included for comprehensive consideration in view of other literature. The intersubject CV which measures group variability and the intrasubject CV which measures precision were lower for the dynamic conditions, however, the VR and ICC suggested reproducibility was best with EMG from the MVIC. Given that other studies have advocated normalizing EMG by taking data from the dynamic event, reconsideration may be warranted if high reproducibility is desired. Interpretations of the findings given the population, muscle and condition studied are discussed.
肌电图（EMG）数据的归一化在科学文献中被描述为在受试者之间和肌肉之间进行比较的关键。然而，归一化方程中使用的参考值在不同的报告中有所不同。通过使用共同值，可以方便地比较研究。我们提出选择共同值的最佳方法是通过可靠性方法。因此，本研究的目的是确定三种 EMG 归一化值中的哪一种提供了最可重复的数据集。参与更大研究的 20 名正常人和 20 名前交叉韧带缺失患者的腓肠肌 EMG 结果被归一化为最大随意等长收缩（MVIC）EMG、峰值动态 EMG 和平均动态 EMG。然后使用四个统计措施评估值：受试者内和受试者间变异系数（CV）、方差比（VR）和组内相关系数（ICC）。虽然 CV 测量值不能反映可靠性，但鉴于其他文献，仍将其包含在全面考虑中。然而，动态条件下的组间 CV（衡量组间变异性）和受试者内 CV（衡量精度）较低，而 VR 和 ICC 表明 MVIC 的 EMG 具有最佳的可重复性。鉴于其他研究主张通过从动态事件中获取数据来对 EMG 进行归一化，如果需要高重复性，可能需要重新考虑。讨论了基于研究人群、肌肉和条件对研究结果的解释。
