"Driving posture and whole-body vibration (WBV) (reported in Part 1) were measured during the operation of seven load-haul-dump (LHD) mining vehicles. Simultaneous exposure to WBV and non-neutral postures could increase an LHD operator's risk of developing a musculoskeletal injury. The percentage of work time spent in neutral, moderate and severe neck rotation, trunk rotation, trunk flexion and trunk lateral bend postures was determined via a 3DMatch analysis of 1 h of videotaped driving for each LHD operator. Peak and cumulative spinal loads at the L4/L5 level also were estimated using 3DMatch. Operators averaged 89% of the time with their necks rotated more than 40°, 3% of the time with the trunk rotated more than 30°, 24% of the time with the trunk in forward flexion between 20° and 45°, and 16% of the time with the trunk in lateral bend between 15° and 30°. The average maximal compressive force (based on static measure estimations associated with posture only) at the L4/L5 level of the spine was 2176 N, and the cumulative compressive load for an 8-h work shift was 34 MN. A total injury risk score, which considered vibration exposure, working postures and spinal loading, was correlated with LHD operator musculoskeletal injury reports. Therefore, exposure to vibration and non-neutral working postures appears to increase musculoskeletal injury risk amongst LHD operators."

Support: Paper