Predicting lifting capacity

Abstract

As science and technology become more sophisticated and with the rapid computation capabilities of the modern computer available, it becomes both possible and economically feasible to scientifically study man and his interaction with his working environment. It is now possible for a person seeking employment to expect and obtain a position which will not be unnecessarily hazardous to his immediate health or have detrimental effects over the long run. Manual materials handling is the contributor of over 400,000 back injuries suffered in the U.S. each year. This research is directed at determining the appropriate operator variables to measure for predicting the permissible weight of lift for three ranges of lift: floor to knuckle height, knuckle height to shoulder height, and shoulder height to reach height. A modified psychophysical procedure was used during which the subjects were instructed to adjust the weight in a tote box to the maximum weight they could lift repetitively without excessive strain or fatique. The task consisted of lifting loads under different conditions of task variables, namely, height of lift, frequency of lift, and load size. Industrial workers as well as students of both sexes were used as subjects. Based on the data obtained, the lifting capacity of the worker was determined for the different ranges of lift. In addition, predictive models were developed based on the operator variables and the task variables investigated.

Container Characteristics and Maximum Acceptable Weight of Lift1

“…at CARLETON UNIV on July 26, 2015 hfs.sagepub.com Downloaded from 488-August, 1980 mine maximum allowable weights and workloads based on the psychophysical criteria (Snook, 1978;Garg and Saxena, 1979;Ayoub, Dryden, McDaniel, Knipfer, and Dixon, 1979). Arguments in favor of psychophysical methodology state that it is simple to use and understand and that it is only the individual worker who can integrate the various sensory inputs into one meaningful response.…”

Employment Standards for Australian Urban Firefighters

“…Firefighters reported that such above-shoulder activities were among the most difficult tasks, 1 and this view is consistent with our understanding of mechanical loading, with lower maximal strength observed for lifts above the shoulder. 31,32 Furthermore, because lower-and upper-limb strength are relatively poor predictors of functional, overhead lifting and holding performance, 33 the use of content-valid tests becomes an important consideration in the design of aptitude tests.…”

Ratings of acceptable load and maximal isometric lifting strengths: the effects of repetition

“…Psychophysical tests of acceptability have not generally been applied for individual assessment. Garg et al (1980) did not find that acceptable levels could be predicted from isometric strength: though Ayoub et al (1979) were able to make predictions from a variety of anthropometric and strength tests. Griffin et al (1984) therefore studied the repeatability of quickly applied, individual assessments of acceptable lifting weights.…”