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该文通过实验研究了油锯振动对操作者手臂掌长肌收缩强度和疲劳的影响．结果表明，振动加速度大小和振动频率对掌长肌收缩强度的影响都很显著，加速度幅值越大收缩越强烈，２７～１２０Ｈｚ条件下的掌长肌收缩都比静态握持时要大，并且２７～８０Ｈｚ范围内掌长肌收缩最强烈，超过１２０Ｈｚ时，与静态握持时基本相同．肌电图频谱中与激振频率相对应的成分占主导地位，随着激振频率增大，与之对应的肌电成分变小，但也有明显的峰波值．振动频率和暴露时间对掌长肌收缩慢波化的影响很显著．与静态负荷比较，８０Ｈｚ附近的振动易引起掌长肌疲劳，而２７Ｈｚ附近的振动则有减轻掌长肌疲劳的效果．握持开始后３ｍｉｎ内，掌长肌收缩的慢波化进展最快，第３～７ｍｉｎ较慢，第７ｍｉｎ开始又加快，说明掌长肌的疲劳进展呈现一定的节奏．
In this paper, the effect of the vibration of chain saw on the contractile strength and fatigue of the operator’s palm’s longus muscle was experimentally studied. The results show that the magnitude of vibration acceleration and the frequency of vibration have significant effects on the contractile strength of the palmaris longissimus muscle. The greater the amplitude of the acceleration, the stronger the contractility. The contraction of the palmar muscle at 27 ~ 120Hz is larger than the static holding In the range of 27 to 80 Hz, the palmar muscle contracts most intensively, and when it exceeds 120 Hz, it is almost the same as the static hold. EMG spectrum and the excitation frequency corresponding to the dominant component, with the excitation frequency increases, the corresponding EMG components smaller, but there are significant peak value. Vibration frequency and exposure time on the palmaris contraction slow wave effect is significant. Compared with the static load, vibrations near 80Hz tend to cause palmar muscle fatigue, while the vibration near 27Hz has the effect of reducing palmar muscle fatigue. Within 3 min after the start of the hold, the slow-wave contraction of the palmar muscle was the fastest, the slowest at the 3 ~ 7 min, and the acceleration at the 7th min. It showed that the fatigue of the palmar muscle was showing a certain rhythm.