A PHYSIOLOGICAL STUDY OF MANUAL LIFTING OF LOADS IN INDIANS

The employment of workers solely for lifting of loads is common in the developing countries. Based on the observed range of variation in an industrial lifting operation, a total of 525 lifting experiments comprising combinations of three different weights of compact loads, lifts to three separate heights from the ground level and three different rates of lifting were carried out on 21 subjects selected from amongst the load lifters. Comparison of the observed energy expenditures of these tasks with the maximum working capacities of the subjects showed that many of the tasks were unduly heavy. Regression equations depicting the relation between the energy expenditure of lifts of different heights with the other two variables are given. A chart linking these variables has also been prepared; this may be helpful in adjusting those lifting tasks which are continued for prolonged periods so that they are of 'acceptable' heaviness.