Assessment of room temperature influence on finger blood flow response induced by short-term grasping of vibrating handle

Objective: To investigate the influence of room temperature on finger blood flow (FBF) change in healthy subjects exposed to short-term grasping of a vibrating handle under different room temperatures. Methods: FBF was measured using a blood flowmeter in six male subjects on the dorsum of the middle phalanx of third finger in both hands once at the end of every minute for an equal duration of 5 min at pre-exposure, during exposure to grasping of vibrating handle with sinusoidal vibration and after exposure. Vibration was generated with a frequency of 125 Hz and an rms acceleration of 40 m/s². Measurements were conducted in four room temperatures of 15±1, 20±1, 25±1 and 30±1°C. Results: Compared with the baseline measurements in the exposed hand during grasping of vibrating handle most significant increase in FBF was observed at 15±1°C (P<0.001) and least at 30±1°C (P<0.05), and after vibration least significant FBF was found at 25±1°C (P<0.05). In case of the unexposed hand significant increase in FBF was exhibited at 20±1°C (P<0.01) and 30±1°C (P<0.01) during vibration, and only at 15±1°C (P<0.05) after vibration. Conclusions: Response in FBF due to grasping of vibrating handle was of different patterns from the baseline measurement under different room temperature conditions in both exposed and unexposed hands and it was influenced by room temperature. Overall, the influence was greater at lower test room temperature, inducing more significant increase in FBF.