Effect of vibration magnitude and repetitive exposure on finger blood flow in healthy subjects

Abstract

In order to study the effect of the magnitude of vibrations and repetitive exposure on finger blood flow, we exposed ten healthy subjects to three experimental conditions: (1) vibration of 3.16 m/s2 at 60 Hz, (2) vibration of 31.6 m/s2 at 60 Hz, and (3) no vibration, as a control. Under the experimental conditions, the right hand was exposed to 5-min vibration three times, with intervening 5-min rests. Meanwhile, the blood flows of both middle fingers were continuously measured with a blood flow meter based on the thermal diffusion method. Finger blood flow was significantly decreased in both hands with exposure to vibrations of 3.16 m/s2 and 31.6 m/s2. Increased magnitude of vibration tended to enhance the decrease in finger blood flow in both hands, and repeated exposure to vibration had cumulative effects on the decrease in finger blood flow in the unexposed left hand.

A New Method for the Experimental Assessment of Finger Haemodynamic Effects Induced by a Hydraulic Breaker in Operative Conditions

“…These observations appear to be consistent with the findings of several other studies, where the vasomotor effects induced by vibration, hence arteriolar blood flow, have been seen to depend on the amplitude of the accelerations transmitted to the hand surface 7,[30][31][32] . Increasing vibration magnitude, measured by an increase in root mean square acceleration magnitude, has been seen to enhance FBF reduction 7,31) .…”

“…Different durations and modes of exposure result in different vasoconstriction effects arising in different ways and lasting for different lengths of time 1,29,31) . A greater reduction in FBF after the test with the low grip occurred in both index fingers and in the right middle finger in 6 subjects, who were probably more susceptible than the others.…”

“…Increasing vibration magnitude, measured by an increase in root mean square acceleration magnitude, has been seen to enhance FBF reduction 7,31) . Similar results are produced by increased duration of hand-transmitted vibration 28) , whereas FBF recovery is delayed by increased vibration intensity 33) .…”

Capillary Supply of the Soft Palate Muscles Is Reduced in Long-Term Habitual Snorers

“…Moreover, experimental high-frequency, low-magnitude vibrations reduce the number of blood vessels per muscle fiber [19]. Besides direct mechanical injury to motor nerves and muscle fibers, reduced blood flow due to impaired sensory feedback and metabolic changes has been proposed [17]. In an experimental study, Curry et al [18] showed that vibration caused decreased tissue perfusion.…”

“…Traumatic vibrations and stretch during snoring might cause neuromuscular damage over time. Although it is not established that the morphological abnormalities in palate tissue of SDB patients is related to mechanical trauma during snoring, longstanding mechanical vibration and muscle stretch are known to cause nerve and muscle fiber damage in human limbs [13,14,15,16] and to impair the microcirculation in the exposed muscles in animals [17,18,19]. …”