Nelson R M, Shedlock M, Kaczmarek C, Gahrs J, MacLaughlin H
Department of Physical Therapy, Lebanon Valley College, Annville, PA, USA.
Electromyogr Clin Neurophysiol. 2003 Dec;43(8):459-64.
Electromyography readings are analyzed noting abnormalities in the parameters of amplitude, duration, and number of phases. Previous studies have demonstrated variability between monopolar needle electrodes (MNEs) and concentric needle electrodes (CNEs) in regard to the above parameters. We hypothesized that a difference in measured parameters would be observed due to the physical differences between the needles. Twenty-three subjects participated in this study. Five readings were recorded from the middle deltoid and the abductor digiti minimi muscles using the MNE, and five readings were recorded using the CNE. A minimal isometric contraction of the tested muscle in the subjects dominant arm was performed. A significant difference was found in amplitudes recorded by the MNE and CNE in both muscles. A significant difference was found in the ADM, and not in the deltoid, with regard to duration. The difference found in the number of phases was clinically insignificant.
The MNE detected larger amplitudes and durations because of its larger recording territory. The duration may also be affected by the distance between the active/reference electrodes.
对肌电图读数进行分析，记录幅度、持续时间和相位数量参数中的异常情况。先前的研究表明，单极针电极（MNE）和同心针电极（CNE）在上述参数方面存在差异。我们推测，由于针的物理差异，会观察到测量参数的差异。23名受试者参与了本研究。使用MNE从三角肌中部和小指展肌记录5次读数，并使用CNE记录5次读数。让受试者优势手臂中的受试肌肉进行最小等长收缩。在两块肌肉中，MNE和CNE记录的幅度均存在显著差异。在小指展肌中，持续时间存在显著差异，而在三角肌中则不存在。在相位数量上发现的差异在临床上无显著意义。
由于MNE的记录区域较大，其检测到的幅度和持续时间更大。持续时间也可能受活动电极/参考电极之间距离的影响。
