MOTOR-UNIT ACTIVITY RESPONSIBLE FOR 8-HZ TO 12-HZ COMPONENT OF HUMAN PHYSIOLOGICAL FINGER TREMOR
MOTOR-UNIT ACTIVITY RESPONSIBLE FOR 8-HZ TO 12-HZ COMPONENT OF HUMAN PHYSIOLOGICAL FINGER TREMOR
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DOI：
10.1152/jn.1976.39.2.370
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发表时间：
1976-01-01
影响因子：
2.5
通讯作者：
RANDALL, JE
中科院分区：
文献类型：
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作者：
ELBLE, RJ;RANDALL, JE
为了阐明生理性手指震颤的8- 12-Hz分量的运动单位活动，记录了6名健康志愿者的伸展第三手指和双极表面的震颤以及指伸肌的针肌电图。在约200-250 g的稳定自主收缩期间，用力传感器测量震颤。对表面EMG进行全波整流和低通滤波（21 Hz时为-3 dB），产生表面EMG的包络（解调EMG）。同时震颤和解调肌电图记录进行频谱分析。在六个科目中的四个，一个明显的8- 12-Hz的振幅调制的表面肌电图是存在的，相干性分析表明，这种调制与众所周知的8- 12-Hz的震颤是密切相关的。在两名受试者中，尽管在本研究中使用了灵敏的记录和分析技术，但这种振幅调制和震颤几乎检测不到。对43个运动单位穗序列进行了频谱分析。22个尖峰序列的平均放电频率在10-22尖峰/s的范围内，除了在平均放电频率处的预期频谱峰之外，还在8-12 Hz处产生统计学显著的频谱峰。在22个产生8至12 Hz的运动单元中，12个的平均放电频率在17-22尖峰/秒的范围内，并且在所有记录的运动单元中表现出最大的8至12 Hz活动。这些运动单位显示出双放电的瞬时序列，其中约8-30 ms的峰间间期（ISIS）与60-90 ms的ISIS交替，从而产生8- 12 Hz的频谱峰。这些运动单位的相邻ISIS在-0.5至-0.9的范围内相关。相干分析表明，这些运动单位的8- 12-Hz的活动与8- 12-Hz的手指震颤和表面肌电图调制。其余10个产生8至12 Hz的运动单元的平均放电频率在10-17 spike/s的范围内。虽然这些运动单位没有显示出强烈的双放电模式的更迅速的发射运动单位，对动作电位分组的趋势是存在的，并导致8- 12-Hz的频谱活动与震颤和表面肌电图调制。.. ..
Tremor of the extended third digit and bipolar surface and needle electromyograms of the extensor digitorum were recorded from six healthy volunteers for the purpose of elucidating the motor-unit activity responsible for the 8- to 12-Hz component of physiological finger tremor. Tremor was measured with a force transducer during steady voluntary contractions of approximately 200-250 g. The surface EMGs were full-wave rectified and low-pass filtered (-3 dB at 21 Hz), producing the envelope of the surface EMG (the demodulated EMG). Spectral analyses of simultaneous tremor and demodulated EMG records were performed. In four of six subjects, a pronounced 8- to 12-Hz amplitude modulation in the surface EMG was present, and coherency analysis demonstrated that this modulation was strongly correlated with the well-known 8- to 12-Hz tremor. In two subjects this amplitude modulation and tremor were barely detectable, despite the sensitive recording and analysis techniques used in this study. Spectral analysis was performed on 43 motor-unit spike trains. Twenty-two spike trains, having mean firing frequencies in the range of 10-22 spikes/s, produced statistically significant spectral peaks at 8-12 Hz, in addition to the expected spectral peaks at the mean firing frequencies. Of the 22 8- to 12-Hz-producing motor units, 12 had mean firing frequencies in the range of 17-22 spikes/s and exhibited the greatest 8- to 12-Hz activities of all motor units recorded. These motor units displayed transient sequences of double discharges in which interspike intervals (ISIS) of approximately 8-30 ms alternated with ISIS of 60-90 ms, thus producing an 8- to 12-Hz spectral peak. Adjacent ISIS of these motor units were correlated in the range of -0.5 to -0.9. Coherency analyses demonstrated that the 8- to 12-Hz activities of these motor units were correlated with the 8- to 12-Hz finger tremor and surface EMG modulation. The remaining 10 8- to 12-Hz-producing motor units had mean firing frequencies in the range of 10-17 spike/s. Although these motor units did not display the intense double-discharge firing pattern of the more rapidly firing motor units, a tendency toward action potential grouping was present and resulted in 8- to 12-Hz spectral activities which were correlated with the tremor and surface EMG modulation. .. ..