Abstract
This paper describes an experiment which utilized a psychophysical approach to determine maximum frequencies of lift acceptable to male industrial workers. Eight subjects were required to lift continuously either a 35-pound or a 50-pound tote box through a 20-inch distance at each of three different heights. The lifting task was paced by a repeating timer which the subject controlled according to his subjective feelings of fatigue. Visual cues were minimized as much as possible. Nonsignificant differences among three replications of the experiment lend strong support for the psychophysical methodology. Comparison of the results with an earlier physiological study reveals that a smaller mean and standard deviation were obtained in this experiment. Negative correlations between selected frequency of lift and subject height and weight are very similar to those reported by other investigators.
