Digital blood flow and temperature responses in palmar and dorsal skin induced by short-term vibration exposure while grasping a vibratory handle.

OBJECTIVE

The present study was designed to examine the simultaneous responses in digital circulation at both palmar and dorsal skin induced by acute exposure to short-term vibration while grasping a vibratory handle, and also to evaluate the importance of measurement site for such responses.

METHODS

Finger blood flow (FBF) and finger skin temperature (FST) were measured from the palmar (index finger) and dorsal (middle finger) regions of the right hand in eight male subjects, at rest for 5 min and while gripping the handle for 15 min. At the end of fifth minute during grasping of the handle, subject's hand was exposed for 5 min to four different exposure conditions (vibration at three frequencies of 31.5, 125 and 250 Hz with a frequency weighted rms acceleration of 5.5 m/s(2), and no vibration).

RESULTS

During vibration exposure relative to the corresponding control conditions, the %change (calculated from before exposure mean value in gripping condition) in dorsal FBF increased substantially (P < 0.01-0.001), and the %change for decreased palmar FST augmented significantly (P < 0.05-0.01) in all frequencies. After vibration exposure, blood flow and skin temperature also remained significantly higher in dorsal finger (P < 0.05-0.005), and significantly lower in palmar finger (P < 0.005-0.001) at different frequencies comparing to the control values. Also, only vibration exposure caused significantly different %changes in digital circulation between palmar and dorsal fingers (P < 0.001).

CONCLUSION

These data suggest that vibration can affect the digital circulation in both palmar and dorsal skin but differently. Therefore, while comparing the data of digital circulatory responses induced by acute exposure to hand-transmitted vibration recorded at palmar and dorsal sides of the hand, cautions are required when interpreting the results.