Why vehicle design matters: Exploring the link between line-of-sight, driving posture and risk factors for injury

Load haul dump (LHD) vehicles have been involved in workplace accidents resulting in fatal injuries and LHD operators also report high rates of musculoskeletal injury. Poor line-of-sight (LOS) and awkward postures adopted by the LHD operator increase the risk of driving related accidents and musculoskeletal injury. The purpose of this case study was to simultaneously measure point of regard (POR), driving posture and sitting position during the operation of a LHD in an underground mining environment in order to further understand the link between these variables and the design of the LHD vehicle. A 5.35 m3 bucket LHD vehicle was used and several driving tasks were analysed. The case study results showed that despite the driving task, the operator looked to the left side of the vehicle 65% of the time. Postural implications include extreme neck rotation (> 40 degrees) for 85% of the work cycle and the average peak compression at L4/L5 was 1843N. Despite changes in driving posture the average center of pressure location for the seated operator moved very little; however changes in peak pressure were observed. The design of the LHD vehicle dictated what the operator could see, which had a direct influence on driving postures adopted by the operator and resulted in several risk factors for musculoskeletal injury.