Strain of employees in the machine industry in Finland.

In order to investigate the strain of workers in different occupations of the Finnish machine industry, energy expenditure and heart rate of 190 men and 47 women employees were measured during their normal course of work. Work was most strenuous in occupations in the early stages of production and in unskilled jobs. The relative strain of semi-skilled workers was highest in the oldest age groups, over 45 years. It is concluded that when systems for grading the strain of industrial work are constructed, the long-term effects of work and workers' characteristics such as age, sex, weight and physical fitness should be taken into consideration.