Workplace factors and trunk motion in grocery selector tasks.
Proceedings of the Human Factors and Ergonomics Society 37th Annual Meeting, October 11-15, 1993, Seattle, Washington, Designing for Diversity. Santa Monica, CA: Human Factors and Ergonomics Society, 1993 Oct; 37(Ind Erg):654-658
The physical demands of warehouse grocery selectors were investigated in three conditioned, male grocery selectors. The job was viewed as repetitively performing order selecting cycles, each cycle taking 15 to 45 minutes to complete. For each order the subject drove a motorized jack to a stack of empty pallets, placed one or two pallets on the rack, and moved along the aisles where the products were stored to select cases as listed on the order form. Statistics were determined for 14 variables including four workplace measures (average load weight, vertical height of the bottom of the box from the floor at liftoff, horizontal distance of the hands from the L5/S1 joint at liftoff, and the estimated lift rate) and ten trunk motion measures (maximum rotation angle, maximum rotation velocity and maximum rotation acceleration of the L5/S1 joint about the sagittal, frontal and transverse planes). The findings suggested that movements in the sagittal plane required the greatest spinal movement, regardless of the height of the lift. The low height lifts were associated with the greatest sagittal rotation angle and highest velocities and accelerations. These tasks would be associated with the greatest biomechanical spine loading, particularly considering the increased accelerations.
Manual-materials-handling; Cumulative-trauma-disorders; Manual-lifting; Repetitive-work; Biomechanics; Warehousing; Back-injuries; Musculoskeletal-system-disorders
Issue of Publication
Proceedings of the Human Factors and Ergonomics Society 37th Annual Meeting, October 11-15, 1993, Seattle, Washington, Designing for Diversity