Cross-sectional Analysis of Whole Body Vibration Exposures and Health Status among Long-haul Truck Drivers

Abstract

Exposure to whole body vibration (WBV) is known to be associated with various adverse health outcomes among professional truck drivers. As a part of a randomized controlled trial, this study evaluated WBV exposures and various health outcomes from 96 professional truck drivers. The WBV was measured and analyzed per International Standards Organization (ISO) 2631-1 and 2631-5 WBV standards. This study also measured self-reported regional body pain (10-point scale), low back disability (the Oswestry Disability Index), and physical/mental health (the Short Form 12-item Health Survey). Lastly, this study evaluated associations between the WBV exposure and various health outcomes. The results showed that the predominant z-axis weighted average vibration [A(8)] measure (Mean ± SE: 0.35 ± 0.01 m/s2) was below the ISO and European Union (EU) daily exposure action limits (0.5 m/s2) whereas the vibration dose value [VDV(8)] measure (12.2 ± 0.3 m/s1.75) was above the ISO and EU daily exposure action limit (9.1 m/s1.75). Self-reported low back pain (LBP) was the most prevalent adverse musculoskeletal outcome reported (72.5%) with average LBP score of 2.9 (SD: 2.0). The SF-12 health scores showed that truck drivers’ physical health status was lower than the average US population (p’s < 0.04). Moreover, the Spearman’s correlations (r_s ) between the WBV parameters and health outcomes indicated that A(8) measures were associated with LBP (r_s = 0.31; r = 0.05) and SF-12 physical composite score (r_s = −0.39; r = 0.02); however VDV(8) was not associated with any of the health outcomes. The study findings indicates that although the impulsive exposures [VDV(8)] were more prominent, the continuous, average vibration [A(8)] appears to be more strongly associated with injury risks. This finding supports the practice of EU countries using A(8) as one of the primary measures for characterizing daily WBV exposures but also complements many other studies indicating that the current EU daily action limit value of 0.50 m/s2 for WBV may be too high.