Data were collected by using 1) a structured interview questionnaire discussing the characteristic of the call
center workers and 2) the rapid office strain assessment (ROSA) that applied from Sonne et al. [7] which measured
the sitting posture, work station (Chair height, pan depth, armrest and back support), computer (Monitor, mouse and
keyboard), telephone and duration of spending time for each posture or activities. ROSA had been designed for
assessment of office workers and can help identified factors relating to discomfort from computer jobs. High inter
and intra-observer reliability was 0.84 and 0.86, respectively