ABSTRACT

In light and moderate work, fatigue results from the requirement to maintain positions of the limbs, or the posture of the whole body, over considerable time. Maintaining a posture requires the involved muscles to keep up a constant contraction, which compresses its own tissues. Breaks in physical work provide time for rest and recovery. They are beneficial for both physiological and psychological reasons. Interrupting the flow of work, especially if it is repetitive, monotonous, or otherwise demanding in either the mechanical or the psychological sense, helps to prevent overload. When the energy requirements of work are low, measuring the worker's oxygen consumption provides little useful information. Many persons with sit-down jobs try to bring up their expenditures by doing demanding leisure activities, workouts, and sports. While a number of modifications to the Nordic Questionnaire have been proposed, it is widely administered, and it therefore provides internationally standardized information.