Data collection
Data collection included interviews using a questionnaire,
physical examination, direct observation and video recording of
the actual work. The questionnaire consisted of demographic
information, physical ergonomic factors and psychosocial factors.
The demographic information included age, sex, educational level,
income, underlying disease and smoking status. The physical
ergonomic factors such as tapping levels from the ground,
twisting, bending, and extension of trunk and weight lifting were
included. In addition, perceived fatigue from work, social support,
family support, work stress, time for relaxation, safety of work and
fear while working at night were collected as psychosocial
variables.