Takanokura Masato, Kokuzawa Naoyuki, Sakamoto Kazuyoshi
Department of Industrial Engineering and Management, Kanagawa University, 3-27-1 Rokkakubashi, Kanagawa-ku, Yokohama 221-8686, Japan.
Eur J Appl Physiol. 2002 Nov;88(1-2):29-41. doi: 10.1007/s00421-002-0677-2. Epub 2002 Aug 14.
To investigate the influence of gravity on physiological tremor during a holding stretch of the finger, tremor during immersion of the finger in liquids was measured. Liquids with various densities and various coefficients of viscosity were used. Tremor was detected using an acceleration sensor, and power spectrum analysis was performed on the acceleration signal of the tremor. The total power of the tremor spectrum decreased with an increase of the density and an increase of the coefficient of viscosity, the high frequency domain of the tremor spectrum showing a larger decrease than the low frequency domain. Linear regression analysis showed that the viscosity of the liquid had a larger effect on tremor than the buoyancy due to the liquid. A model was proposed for tremor during immersion of the finger in liquid. The effect of the buoyancy and the viscosity on tremor was examined using the proposed model. The origin of two frequency bands in the tremor spectrum was verified by both the immersion experiment and the proposed model. The stretch-reflex system via the spinal cord produced a high frequency band around 25 Hz, while the supraspinal system caused a low frequency band around 10 Hz. The neuromuscular function of the human body was evaluated using the amplitude and the frequency of tremor.
为了研究重力对手指持续伸展过程中生理震颤的影响，测量了手指浸入液体时的震颤情况。使用了具有不同密度和不同粘度系数的液体。通过加速度传感器检测震颤，并对震颤的加速度信号进行功率谱分析。震颤频谱的总功率随着液体密度的增加和粘度系数的增加而降低，震颤频谱的高频域比低频域下降幅度更大。线性回归分析表明，液体的粘度对震颤的影响大于液体的浮力。提出了一个手指浸入液体时震颤的模型。使用该模型研究了浮力和粘度对震颤的影响。通过浸入实验和所提出的模型验证了震颤频谱中两个频段的起源。经由脊髓的牵张反射系统产生了一个约25Hz的高频段，而上脊髓系统则引起了一个约10Hz的低频段。利用震颤的幅度和频率评估了人体的神经肌肉功能。
