Comparative study of the work load between one-man buses and two-man buses.

The differences in physiological and safety conditions of one-man buses and two-man buses were examined from the view point of occupational fatigue. This survey consisted of a work load study which included a time study, study of subsidiary behavior, auditory task, memory test, Galvanic Skin Response (GSR) and physiological function tests and a self-administered questionnaire which involved items concerning safety and subjective fatigue complaints. The visual and postural restrictions in the one-man bus were greater than in the two-man bus. The mental capacity of the one-man bus drivers was found to be less. Greater mental fatigue and stress were observed in the one-man bus. More subjective fatigue complaints were observed in the one-man bus. More cases of near accidents were observed in the one-man bus. From these results it was concluded that the one-man bus caused bus drivers a greater mental and physical work load.</p

Studies on low back pain among workers in a train repair factory -The incidence and occupational cause of low back pain and the influence of low back pain on activities in daily life-

Owing to the changes in working conditions brought about by mechanization, the occupational causes of low back pain (LBP) have shifted from dynamic factors to static ones. In the train repair factory, however, the workers must operate in such narrow working spaces that it is difficult to use machines. Therefore, the workers must often move heavy materials by hand and perform their duties in unnatural postures. The author deals with health problems induced by LBP among workers engaged in locomotive repair. All of the workers (178) were examined by questionnaire, and 120 workers who were suffering from LBP or had taken sick leave on account of LBP were summoned for a medical examination. The questionnaire consisted of twenty items specially selected to evaluate the influence of LBP on activities in daily life. Twenty-five workers (14.0%) complained of continuous LBP, and 89 workers (50.0%) complained of occasional LBP. The workers in this factory had a higher prevalence of LBP than the workers in many other factories. The rate of complaints concerning LBP rose according to the increase in the frequency of unnatural postures and the handling of heavy materials during work. It was demonstrated that LBP had a harmful influence on activites in daily life