Author(s): Oliveira, Elsa ; Rodrigues, Matilde ; Silva, Manuela ; Azevedo, Rui ; Carvalho, Alberto
Date: 2012
Persistent ID: http://hdl.handle.net/10400.24/1906
Origin: Repositório Científico da UMaia
Subject(s): Index of Perceived Exertion; Maximum Acceptable Weight; Psychophysical; Transportation Manual of Loads
The psychophysical criteria are important to develop manual material handling guidelines. It is essential that the studies that use a psychophysical approach be carried out as accurately as possible. However, the sample used in these studies can influence the results, if not appropriate. This work intends to analyze the influence of the sample in determining the maximum acceptable weight (MAW) in tasks of manual transport of loads transportation. The study involved 10 students and 10 workers. The participants’ task was to carry a box for 13 minutes and travel six meters. The box had the dimensions of 60 cm length × 40 cm width x 40 cm deep and the handles had 2.7 cm width and 9.0 cm in length. Moreover, subjects were required to carry out the movement of the box with the trunk erect and the forearms perpendicular to the body. In the end, the MAW and the rate of perceived exertion (RPE) were determined. A strength test was applied to each individual. The MAW was higher for students (11.6kg) than for workers (10.8kg), however, it was not verified significant differences between groups. For students, the MAW depended on the selected IW. Students also assigned RPE values higher than workers. These results suggest that the workers' experience may be a determining factor in the MAW. Although the study has not provided conclusive results, it can be argued that samples comprised by students may affect the results, being that these groups of samples should be used with caution. So, whenever possible it should be used experienced workers in real work context for psychophysical studies.
