Comparing Results of Four Lifting Analysis Tools

Abstract

Four lifting analysis methods (WA L&I, NIOSH, ACGIH TLV, and 3DSSPP) were used to assess milk case stocking of 4- and 6-gallon cases. The outputs of each method were converted to a risk index similar to NIOSH's Lifting Index and used to contrast and compare risk predictions. All instruments showed higher risks associated with lifting the 6-gallon cases versus the 4-gallon cases. The NIOSH and ACGIH TLV methods were virtually identical in their results and predicted substantially higher risk when compared to the 3DSSPP. WA L&I showed risk only at the higher lifts, but its threshold for risk was designed to be higher for regulatory purposes. NIOSH's multi-task analyses were also performed. For the practitioner, the ACGIH TLV is a simpler tool to use and yields results similar to the NIOSH single-task analysis for this type of lifting, but NIOSH offers greater interpretive capabilities. All of the instruments may underestimate the risk of this lifting task due to the presence of factors unaccounted for in their calculations. The differences, strengths, and limitations of each method are outlined.