Maximum acceptable weight of lift for asymmetric lifting

10 undergraduate men were tested to determine the effects of lifting mode and frequency on psychophysically established maximum acceptable weight of lift for 4 hr. of work. The heart rate and rate of perceived exertion (RPE) of the individuals while lifting the maximum acceptable weight of lift were measured. When performing a 90 degrees asymmetric lifting, subjects lifted approximately 10% less weight than lifted in symmetric lifting. Nonsignificant differences in maximum acceptable weight of lift, heart rate, and RPE values were found between asymmetric lifting with trunk rotation and asymmetric lifting with leg rotation. The lifting frequency significantly affected the maximum acceptable weight of lift, heart rate, and RPE. Heart rate and RPE increased with lifting frequency. The maximum acceptable weight of lift at 2 lifts/min. and 4 lifts/min. were approximately 91.5% and 82.5% of that of 1 lift/ min., respectively.