The effects of police duty belt and seat design changes on lumbar spine posture, driver contact pressure and discomfort

Police officers spend large amounts of time performing duties within a police cruiser and report a high prevalence of musculoskeletal problems. This study evaluated the effects of driver seat and duty belt design on posture, pressure and discomfort. Ten male and 10 female university students attended two sessions involving simulated driving in a standard police seat (CV) and an active lumbar support (ALS) seat. Participants wore a full duty belt (FDB) or reduced duty belt (RDB) in each seat. Lumbar postures, driver-seat and driver-duty belt pressures and perceived discomfort were measured. GenderxSeat interactions were found for pelvic (p=0.0001) and lumbar postures (p=0.003). Females had more lumbar flexion than males and were more extended in the ALS seat (9.8 +/- 11.3 degrees) than CV seat (19.8 +/- 9.6 degrees). The FDB had greater seat pressure than the RDB (p<0.0001), which corresponded to increased pelvis discomfort. This study supports the use of an ALS seat and RDB to reduce injury risk associated with prolonged sitting in police officers. Practitioner Summary: Police officers report a high prevalence of musculoskeletal problems to the lower back, associated with prolonged driving and further investigation is needed to reduce injury risk. This simulated driving study investigated seat and duty belt configuration on biomechanical measures and discomfort. Seat design had the greatest impact, regardless of gender and males benefited more from a reduced belt configuration.