EFFECTS OF GROUND CONDITIONS ON WHOLE-BODY VIBRATION EXPOSURE ON CARS: A CASE STUDY OF DRIVERS OF ARMORED VEHICLES

The purpose of this paper is to highlight how the types of road and the vehicle characteristics influence the whole-body vibration (WBV) exposures. WBV exposure is common in occupational drivers and it can generate serious musculoskeletal injuries of the arms, shoulders, neck and lower back. Numerous studies have shown that many factors influence the dose exposure: the driver's position, style guide, vehicle speed and the driver's physical characteristics, such as body weight and height. In order to point out possible interactions between exposure to whole body vibration, vehicle characteristics and the types of road, an experimental campaign was created: firstly, a model standard car for urban use was utilized, and later, the same model vehicle was modified by the armour-plate installation for the ballistic protection. Each vehicle was driven by the same driver for a defined time on a curvilinear common urban route, along both rise and downhill directions. The assessment of the daily vibration dose was carried out in accordance with ISO 2631-1(1997) standard and expressed as the weighted frequency equivalent continuous root mean squared (RMS) acceleration over an eight-hour period. The results obtained from the experimental campaigns revealed that the WBV exposure is strongly conditioned by vehicle characteristics. In particular the installation of bulletproof armour contributed to change the car mass distribution and its total weight, modifying the professional dose. This modification generated an attenuation of frequency-weighted RMS. acceleration values all over the frequency spectrum and consequently a WBV exposure reduction. The present study encourages further study in order to understand how different factors influence exposure to WBV research.