Fatigue Complaints and Critical Fusion Frequency of Flicker of Workers in a Manufacturing Workshop

The value of critical fusion frequency of flicker (CFF) was measured and questioning about fatigue complaints was done for healthy male workers at a manufacturing workshop. The following results were obtained. 1) The frequency of fatigue complaints in the aged group was significantly higher than that of the younger group. 2) The proportion of fatigue complaints of each of three types to those in total was different in order by the age group. 3) The frequency of fatigue complaints in total was not significantly differtiated by the shift at the termination of working hour. 4) The percent changes of frequency of fatigue complaints during a day were less than 8% in any type of shifts and no significant differences was seen between the types of shift. And the percent changes during a week was significantly higher in the early attendance shift than in the others. 5) The value of CFF in aged group was significantly lower than that of the younger group. 6) Two times of peak were seen in the changes of CFF during a day in 12-hours duty shift. 7) The decreasing change in the value of CFF was not seen during a day or a week in any type of shifts. 8) The mental load upon the worker in this workshop was considered to be a relatively light one compared with that in the other manufacturing workshops.