Workload assessment in manual materials handling tasks in rice mills in India

Background Manual materials handling (MMH) tasks in rice mills in India are labour intensive. Objective Investigation of physical workload on seven manual material handling (MMH) tasks among male workers in rice mills and comparison of the VO 2 obtained from experiments in the present study with the models developed for Indian workers. Methods Experiments were performed to measure the working heart rate (HR) in the eight rice mills and submaximal test was performed to measure oxygen uptake (VO 2 ) in the laboratory. A model was developed to estimate the VO 2 during MMH tasks for workers in rice mills. Results The workload was observed to be comparatively higher in carrying 50 kg rice bags from the godown to vehicles and for this task, the mean values of working HR, ΔHR, peak HR and VO 2 were 129 bpm, 56 bpm, 150 bpm and 1.17 l/min, respectively. The workload to fill rice in the bags was relatively lower and the working HR, VO 2 and ΔHR were 110 bpm, 0.95 l/min and 40 bpm, respectively. The VO 2max of all the tasks was higher than the 35% VO 2max for 8-h work for Indian workers. The VO 2 prediction models developed so far for Indian workers underestimated the actual VO 2 in the MMH tasks in the rice mills. The accuracy of the developed model was 0.92. Conclusion According to workload classification, MMH tasks in the rice mills varied from moderate to heavy tasks. There is a need for reducing the workload of the rice mill workers.