Psychophysically determining the maximum acceptable weight of lift for polypropylene laminated bags.

The objective of this study was to psychophysically determine the maximum acceptable weight of lift (MAWL) for polypropylene (PP) laminated bags. Twelve men were requested to decide their MAWLs under various task combinations involving 3 lifting ranges, 3 lifting frequencies, and 2 hand conditions. The results revealed that the MAWL was significantly affected by the frequency and range variables (all p<.001), whereas the hand condition did not influence the MAWL. The participants exhibited relatively low MAWL values compared with subjects in previous studies, especially in infrequent lifts. The results of multiple stepwise regression revealed that certain anthropometric data (e.g., chest circumference, wrist circumference, and acromial height) accounted for the percentage of variance for the determined MAWLs, ranging from 56.2% to 83.4%. These data can be obtained simply and quickly, and are considered the superior predictors for MAWL determination when handling PP laminated bags.