Reductions in finger blood flow in men and women induced by 125-Hz vibration: association with vibration perception thresholds

Abstract

Ye Y, Griffin MJ. Reductions in finger blood flow in men and women induced by 125-Hz vibration: association with vibration perception thresholds. J Appl Physiol 111: 1606 -1613, 2011. First published September 15, 2011 doi:10.1152/japplphysiol.00407.2011.-Vibration of one hand reduces blood flow in the exposed hand and in the contralateral hand not exposed to vibration, but the mechanisms involved are not understood. This study investigated whether vibration-induced reductions in finger blood flow are associated with vibrotactile perception thresholds mediated by the Pacinian channel and considered sex differences in both vibration thresholds and vibration-induced changes in digital circulation. With force and vibration applied to the thenar eminence of the right hand, finger blood flow and finger skin temperature were measured in the middle fingers of both hands at 30-s intervals during seven successive 4-min periods: 1) pre-exposure with no force or vibration, 2) pre-exposure with force, 3) vibration 1, 4) rest with force, 5) vibration 2, 6) postexposure with force, and 7) recovery with no force or vibration. A 2-N force was applied during periods 2-6 and 125-Hz vibration at 0.5 and 1.5 ms Ϫ2 root mean square (r.m.s.; unweighted) was applied during periods 3 and 5, respectively. Vibrotactile thresholds were measured at the thenar eminence of right hand using the same force, contact conditions, and vibration frequency. When the vibration magnitude was greater than individual vibration thresholds, changes in finger blood flow were correlated with thresholds (with both 0.5 and 1.5 ms Ϫ2 r.m.s. vibration): subjects with lower thresholds showed greater reductions in finger blood flow. Women had lower vibrotactile thresholds and showed greater vibration-induced reductions in finger blood flow. It is concluded that mechanoreceptors responsible for mediating vibration perception are involved in the vascular response to vibration.

Relation between vibrotactile perception thresholds and reductions in finger blood flow induced by vibration of the hand at frequencies in the range 8–250 Hz

“…This is consistent with other experimental studies suggesting a neurogenic reflex may be involved in the vascular response of the digital vessels to acute exposures to hand-transmitted vibration (Hyvärinen et al, 1973;Bovenzi et al, 1995;Thompson and Griffin, 2009;Ye and Griffin, 2011a). A greater vasoconstriction on the vibrated right hand is also consistent with previous studies Ye and Griffin, 2011a) and suggests there is also a local mechanism involved in vasoconstriction during exposure to vibration.…”

“…It was therefore not clear whether increased vasoconstriction was caused by the greater magnitude of vibration, the greater area of excitation, or both. Using the same arrangement as the current study (a vibrating probe with a fixed surround) so as to control the area of excitation, a greater reduction in finger blood flow has been found with greater vibration magnitudes (Ye and Griffin, 2011a), as in the present study. Using a similar arrangement to the current study but with two sizes of probe (3-mm and 6-mm diameter) greater reductions in finger blood flow have been found with the greater contact area (Ye and Griffin, 2013).…”

“…With greater magnitudes of vibration there is greater vasoconstriction in the digital vessels (Bovenzi et al, 1999;Thompson and Griffin, 2009;Ye and Griffin, 2011a). With progressive increases in the frequency-weighted acceleration from 0 to 15 ms -² r.m.s., vibration induces progressively greater reductions in finger blood flow at all frequencies in the range 16 to 315…”

“…For such a reflex to be involved there must be mediation of the vibratory stimulus, such as the excitation of mechanoreceptors by vibration (Ye and Griffin, 2011a).…”

“…Reductions in the blood flow in individual fingers induced by 125-Hz vibration at 0.5 and 1.5 ms -2 r.m.s. have been found to be associated with individual absolute thresholds for perceiving 125-Hz vibration via the Pacinian channel (Ye and Griffin, 2011a). This suggests some vascular changes provoked by vibration may be related to the sensations produced by the vibration, as assumed for frequency weighting W h , at least for vibration conditions where sensations are mediated by the Pacinian channel.…”