Truck drivers suffer from numerous health issues, predominantly musculoskeletal disorders in the low back that have been strongly associated with exposure to whole body vibration (WBV). Recently, a new and innovative technology that reduces WBV has become commercially available. These new electromagnetic active vibration cancelling (EAVC) seat suspension systems counteract vibration detected at the floor of the cab through linear motors. Due to far greater fidelity in frequency response, these EAVC systems are far superior in reducing WBV compared to the conventional pneumatic suspension systems. As demonstrated in our preliminary work, the EAVC systems reduced average vibration exposures by up to 50% compared to the conventional air-suspension seats that are supplied as standard equipment in most semi-trucks in the United States. We propose a randomized controlled field trial evaluating the effects of an EAVC seat suspension system on a robust set of low back pain and disability outcomes. One hundred forty (140) long-haul truckers with low back pain at baseline will be randomized to receive a new EAVC seat (intervention) or a conventional air-ride seat (control). We will test the general hypothesis that truckers who receive the EVAC seat suspension systems will experience greater reduction in low back pain outcomes and WBV exposure compared to truckers who receive a standard air-ride seat (the control). Pre-and post pain and work diaries will be completed by truckers weekly for 4 weeks prior to the intervention and for 12 weeks post intervention. Surveys of low back pain severity and disability, general health, work-role functioning, and work environment will occur at baseline and follow-up at 3, 12, and 24 months post-intervention. In addition, we will complete WBV exposure assessment measures at pre and post intervention and at 12 and 24 month follow-up. The new and innovative suspension technology provides a seminal opportunity to use an RCT design to determine whether substantially reducing WBV exposures has an effect on low back pain outcomes.
Through the use of a new and innovative seat suspension technology, an engineering control that substantially reduces exposure to WBV, this proposal will determine if reducing the intensity of WBV exposures improves the severity of low back pain in US long-haul trucker drivers.