Background:

musculoskeletal disorders (MSDs) are among the major occupational health problems not only in Chile but at the international level. In this sense, epidemiological studies indicate that one of the potential risk factor of MSDs corresponds to manual material handling. In this regard, the Chilean legislation does not consider methods for risk assessment of MSDs associated with manual material handling with one hand.

Aim:

to determine the lifting and lowering load capacity by one hand in male workers.

Material and Methods:

The study was carried out in a public hospital and in a metallurgical industry from the Province of Concepción. The workers that participated in the study carried out activities associated with both manual material handling and/or patient handling. To determine the maximum acceptable weight (MAW), psychophysical tests were applied. The values of MAW were established when the group handled loads with distances between floor and elbow and between elbow and vertical arm reach heights. Different frequencies were studied, each one handling load every 10 seconds, 1 minute, 30 minutes, 1 hour and 8 hours.

Results:

For the analyzed tasks, values of MAW protecting the 10%, 25%, 50%, 75% and 90% of the group studied were determined.

Discussion:

The results obtained were compared in this study using bibliographic references of handling load capacity with both hands. The values of MAW for one hand found in this study are between 55% up to 69% lower than those values registered for two hands, according with the literature reviewed. To validate the results obtained it is necessary to carry out complementary studies, in order to continue advancing in the development of methods, criteria and regulations applicable to lifting or lowering load with one hand.