Ryan Blood

Project title: Whole-Body Vibration (WBV) Exposures among Professional Drivers: Evaluation of Engineering Interventions to Reduce Low Back Injuries

Degree: PhD | Program: Environmental and Occupational Hygiene (EOHY) | Project type: Thesis/Dissertation
Completed in: 2013


Assessing physical exposures in occupational health studies proves challenging regardless of the
industry. In transportation, however, the problem is exacerbated by the fact that subjects are literally
on the move. To improve the understanding of the link between chronic whole-body vibration exposure
and adverse health outcomes, this study evaluated epidemiologic trends, comparing injury events
among employees in a large metropolitan transit agency. The epidemiology results indicate that bus
drivers are at increased risk for injury compared to a referent group of administrative workers.
This study also presents the technological advancements in field-based, whole-body vibration (WBV)
exposure assessment by comparing three generations of WBV data collection equipment. This study
presents the ISO 2631 Part 1 and Part 5 results for field-based WBV exposure studies among professional
truck drivers, bus drivers, and heavy equipment operators.
Finally, this study applied field-collected vibration signal data to research on a vibration simulation
hexapod. The final phase of this study evaluated vibration attenuation, comparing the current industry
standard (an air-ride suspension seat) to a newly developed technology (an electromagnetically active
seat) across city streets, freeways, and rough roads. This comparison of seat suspension technologies
was conducted for evaluation between professional truck drivers and bus drivers, and it included a
measure of vibration transmission through the spines of subjects. The results indicate that the electromagnetically
active seat is a promising engineering control that may prevent injuries over the long term.
This study combined several research approaches that are important to the field of occupational
health. The goal of this research was to improve the understanding of injury risk and intervention
options, with the ultimate goal of improving the lives of professional bus drivers.