Pain, numbing, and blanching of the fingers are the result of vibration from hand-held tools but many key aspects of the problem are not well understood.
NIOSH hopes to identify ways for effectively reducing risks of hand-vibration disorders for employees using tools such as power drills and other vibrating tools.
Some of the studies are seeking to identify early warning signals as predictors of adverse effects. One study is using advanced microscope technologies to determine if adverse effects from vibrating tools can be predicted from physical changes in the capillaries at the base of the fingernail cuticle, too small to see with the naked eye.
Another is developing a computer model of stress and strain on the fingertips from vibrating tool handles, as measured by the degree to which the soft tissues of the fingertips are compressed or displaced by the vibrating handle.
NIOSH is also assessing infrared thermal imaging of the hands as a potential method for identifying the presence and severity of hand-arm vibration syndrome. This is based on previous research showing that the temperature of the fingertips - after exposure to cold - returns to normal more slowly in a person with hand-arm vibration syndrome.
A method is being designed to measure the impact of a chipping hammer bit and the degree of vibration from the handle. Finally, anti-vibration gloves are being tested using an instrumented vibrating handle that simulates specific tools and vibration characteristics.
Further information on NIOSH's hand-arm vibration research can be obtained from Ren G. Dong, NIOSH Health Effects Laboratory Division, [email protected].
