Characterization of frequency-dependent responses of the vascular system to repetitive vibration.

Objective: The current frequency weighting proposed in the International Standards Organization-5349 standard may underestimate the risk of injury associated with exposure to vibration >100 Hz. The goal of this study was to assess the frequency-dependent responses of the peripheral vascular system to repeated bouts of vibration.

Methods: The effects of exposure to vibration at 62.5, 125, or 250 Hz (constant acceleration of 49 m/s2) on vascular morphology, oxidative stress, inflammation, and gene expression were examined in the ventral tail artery of rats.

Results: Vascular responses indicative of dysfunction (eg, remodeling and oxidative activity) became more pronounced as the frequency of the exposure increased.

Conclusion: Exposure to vibration frequencies that induce the greatest stress and strain on the tail (ie, >100 Hz) result in vascular changes indicative of dysfunction.