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Patterns of differences between the maximum weights of lift acceptable to experienced and inexperienced materials handlers.
Ergonomics 1987 Aug; 30(8):1137-1147
A study of the differences in maximum acceptable weight that could be lifted (MAL) by inexperienced and experienced industrial workers was conducted. Seventy four students, of which 37 were males, lifted boxes of three sizes (30.48, 45.72 or 60.96 centimeters long in the sagittal plane) to three heights (floor to knuckle, knuckle to shoulder, or shoulder to reach) at four lifting frequencies (1, 4, 8 or 12 lifts per minute). The subjects adjusted the weights in each box to arrive at the maximum weight they were willing to lift for a given box size, lifting height and lift frequency. The MAL and steady state heart rate and oxygen uptake at the MAL were monitored for experiments that simulated work shifts of 8 and 12 hours. Anthropometric measurements such as body weight, shoulder height, knee length, chest width and depth, and isometric arm, shoulder and back strength were made. The data were compared with data obtained previously for industrial workers. The isometric strength capability and body size of the two groups were very similar. For the simulated 8 hour work shifts, the average MAL for male students was 11 percent less than that for male industrial workers. The MAL of female students averaged 6 percent less than that of the female industrial workers. The differences were statistically significant. For the 12 hour shifts, the MAL for the students averaged 2 percent less than that for the experienced workers, for both sexes. The heart rates and rates of oxygen consumption of the students generally decreased at a slower rate than those of the industrial workers. The author concludes that experience on the job significantly influences the normal MAL of workers, and that experienced and inexperienced workers generally respond to task variables similarly.
NIOSH Publication; NIOSH Grant; Materials handling; Physical capacity; Humans; Ergonomics; Physiological measurements; Oxygen uptake; Weight factors; Anthropometry
Issue of Publication
Mechanical and Industrial Engr University of Cincinnati Dept of Mec & Indus Engrg Cincinnati, OH 45221
Page last reviewed: April 9, 2021
Content source: National Institute for Occupational Safety and Health Education and Information Division