The Optimal Placement of Boxes on the Shelves of a Food Product Warehouse

An experimental study was undertaken to optimize the placement of boxes on the shelves in a food product warehouse by minimizing joint loadings on the shoulders and on the lower back as criteria. A dynamic sagittal plane model was used to estimate net muscular moments on the shoulders, and a model of internal forces was used to estimate compression forces on the L5/ SI intervertebral disk. Lifting boxes of 6.4 kg or more produced compression forces at L5/S1 above the “action limit” of the National Institute for Occupational Safety and Health (NIOSH, 1981). Regression methods were then used to estimate joint loadings for each product at each working height and for each task. Optimizing the placement of products by minimizing loadings on the lower back reduced overall loadings by as much as 15% for certain racks. For minimizing loadings on the shoulders, results indicated that this variable Was not sensitive to different placements of boxes on the shelves.