Motor-unit activity in the trapezius muscle during rest, while inputting data, and during fast finger tapping
Motor-unit activity in the trapezius muscle during rest, while inputting data, and during fast finger tapping
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休息期间、输入数据时以及快速手指敲击期间斜方肌的运动单位活动
DOI：
10.1007/s004210000277
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发表时间：
2000
影响因子：
3
通讯作者：
H. Krueger
中科院分区：
文献类型：
--
作者：
T. Kitahara;M. Schnoz;T. Läubli;P. Wellig;H. Krueger
灰姑娘假说假设在低水平肌肉收缩时特定运动单元的持续活动，与运动单元替代的概念相矛盾。有报道称，在典型的视觉显示单元相关任务中，斜方肌持续活动。如果能证明持续的肌肉活动是由单个运动单元的连续放电引起的，这就可以解释电脑用户经常抱怨的肌肉颈部疼痛。本研究调查了闭着眼睛休息时斜方肌的运动单元活动，同时以0.5 Hz的频率输入三位数的听觉呈现，同时用右手食指以5 Hz的频率敲击键盘。将四根细丝电极插入6名健康受试者的右上斜方肌，记录三通道肌内肌电图。用于分析短期单通道信号的分解程序MAPQuest与MAPView相辅相成，后者将10秒的短期结果合并为3分钟的分析结果。结果表明，1名受试者在休息时，2名受试者在输入数据时，5名受试者在手指敲击时，斜方肌被诱发活动。两名受试者在输入数据时观察到长时间的单运动单元放电，一名受试者在手指敲击时观察到长时间的单运动单元放电。虽然我们的研究结果可能支持灰姑娘假说，但测量周期太短，无法完全证实它，为了进一步讨论，有必要记录和分析更长的时间。
The Cinderella hypothesis postulates the continuous activity of specific motor units during low-level muscle contraction and contradicts the concept of motor-unit substitution. Constant trapezius muscle activity has been reported in typical visual-display-unit-related tasks. If it can be shown that constant muscle activity can be caused by the continuous firing of single motor units, this could explain the frequent complaints of muscular neck pain reported by computer users. The present study was undertaken to investigate motor-unit activity in the trapezius muscle during resting with closed eyes, while inputting three-digit numbers with auditory presentation at a rate of 0.5 Hz, and while tapping on a key with the right index finger at a rate of 5 Hz. Electrodes with four fine wires were inserted into the right upper trapezius muscle of six healthy subjects, and three-channel intramuscular electromyography was recorded. The decomposition programme MAPQuest, developed to analyse short-term one-channel signals, was complemented with MAPView, a programme that merges the short-term results of 10 s to a 3-min analysis. The results showed that activity in the trapezius muscle was induced in one subject while resting, in two subjects while inputting data, and in five subjects while finger tapping. Long-lasting single motor-unit firing was observed in two subjects while inputting data and in one subject while finger tapping. Whilst our findings may support the Cinderella hypothesis, the measurement periods are too short to confirm it fully, and for further discussion it is necessary to record and analyse for longer periods.