Lifting Limits of Rice-Bag-Carrying Tasks Using a Work Physiological Approach

Abstract

An experiment was designed and conducted to accomplish the following objectives:

Comparison of the physiological responses, as measured during carrying activities in different sizes of rice-bags and in different types of carrying tasks.

Development and testing of a mathematical model for the prediction of the acceptable weight of rice-bags carrying using the criterion of an individual's VO₂ value at 30%VO₂max, A sub-maximal exercise protocol was applied to predict the aerobic capacity (VO₂max) using a bicycling exercise protocol. The physiological responses were heart rate (bpm) and oxygen consumption (1/min). The individual safe weight was considered as the dependent variables from the criteria 30%VO₂max, and age, anthropometric data and strength data were used as the independent variables.

Ten male workers, 25–42 years of age, were paid to work as subjects of the experiment. All were employed to carry rice bags as their primary job.

The results of the experiment were analyzed using the analysis of variance procedure. The predictive models of the safe weight was developed using a backward multiple linear regression technique. The model was validated using 3 extra subjects. It was concluded that the model could reasonably predict the safe weight based on the 30%VO₂max. It was suggested that the safe weight for the rice-bag be about 100 kg.