Nishiyama K, Taoda K, Yamashita H, Watanabe S
Department of Preventive Medicine, Shiga University of Medical Science, Japan.
Int Arch Occup Environ Health. 1996;69(1):45-52. doi: 10.1007/BF02630738.
This study examines the effect of the force with which a vibrating handle is gripped on the temporary threshold shift of vibratory sensation (TTSv) induced by hand-arm vibration.
Six healthy subjects gripped a handle vibrating with a 1.3 octave-band vibration, with a central frequency of 200 Hz and an intensity of 39.2 m/s2. Exposure was for 1 min and 10 min, respectively. Gripping forces for the 1-min exposure were 5 N, 10 N, 40 N and 80 N, respectively, with 0 N push-pull force. Gripping forces for the 10-min exposure were the same as for the 1-min exposure but omitting 80 N. The vibratory sensation threshold at 125 Hz was measured before and after exposure of an exposed fingertip to vibration. The differences measured determine TTSv.t at time t. TTSv.t determines TTSv.0, that is, the temporary threshold shift of vibratory sensation immediately after exposure to vibration according to the estimate made on the basis of the preceding study. The same experimental conditions were repeated 3 times on different days in a soundproof and thermoregulated room.
Our findings show that TTSv increases significantly with increasing gripping force. We also determined the quantitative relationships between TTSv.0 and gripping force as described by the equation TTSv.0 = exp(kf x F + Cf). where kt and Cf are constants and F is gripping force.
This study revealed the importance of ergonomic design in reducing the force with which a vibrating handle is gripped to prevent an adverse effect of local vibration. The equation devised may help in the quantitative assessment of the effect of reduced gripping force.
本研究考察握持振动手柄的力度对手臂振动引起的振动觉暂时阈移（TTSv）的影响。
6名健康受试者握持一个以1.3倍频程带振动的手柄，中心频率为200Hz，强度为39.2m/s²。暴露时间分别为1分钟和10分钟。1分钟暴露时的握持力分别为5N、10N、40N和80N，推拉力为0N。10分钟暴露时的握持力与1分钟暴露时相同，但省略80N。在暴露的指尖接触振动前后，测量125Hz时的振动觉阈值。测量的差值确定时间t时的TTSv.t。根据先前研究的估计，TTSv.t确定TTSv.0，即接触振动后立即出现的振动觉暂时阈移。在隔音和温度调节的房间里，在不同日期重复相同的实验条件3次。
我们的研究结果表明，TTSv随握持力的增加而显著增加。我们还确定了TTSv.0与握持力之间的定量关系，用方程TTSv.0 = exp(kt×F + Cf)描述。其中kt和Cf是常数，F是握持力。
本研究揭示了人体工程学设计在降低握持振动手柄的力度以防止局部振动不良影响方面的重要性。所设计的方程可能有助于定量评估降低握持力的效果。
