Effects of temperature on reductions in finger blood flow induced by vibration

To investigate how temperature influences changes in finger circulation induced by hand-transmitted vibration in healthy subjects, and the variability in individual response to both vibration and temperature.

With two room temperatures (20 and 28°C), finger blood flow (FBF) and finger skin temperature (FST) were measured on the left middle fingers of 12 subjects at 1-min intervals during three successive 10-min periods. A 5-N static force was applied throughout the 30-min period, and sinusoidal 125-Hz vibration at 44 ms(-2) rms. (unweighted) was applied to the right hand during the second of the three 10-min periods.

Before exposure to vibration, both FBF and FST were greater with the higher room temperature. Finger blood flow in the left hand reduced during vibration of the right hand. The reduction in absolute FBF differed between the two room temperatures, but the percentage reduction in FBF relative to FBF before exposure to vibration was similar. After cessation of vibration, there was continued reduction in FBF with both room temperatures. Before and after vibration exposure, the FST was correlated with FBF and the FBF and FST at 20°C were correlated with the FBF and FST at 28°C.

Vibration of one hand can reduce finger blood flow and skin temperature on the unexposed hand, with the reduction dependent on temperature. The absolute reduction in FBF was greater with the higher room temperature, but the percentage reduction in FBF relative to FBF before vibration exposure was similar. Those with greater finger blood flow before vibration tend to have greater blood flow during vibration, and those with greater finger blood flow with one temperature tend to have greater blood flow with another temperature.