The effect of work-rest schedules and type of task on the discomfort and performance of VDT users

Abstract

Consideration of the literature survey indicates that video display terminal (VDT) operators tend to have a high incidence of musculoskeletal problems, visual fatigue, and job stress. Although a number of ergonomic improvements in workstation design and work environment can help to reduce these problems, a proper work-rest schedule deserves consideration since it is easily applicable and inexpensive. The objective of this study was to compare the work-rest schedules for VDT operators considering data entry and mental arithmetic tasks. An experiment was conducted with 10 male college students as participants. The methodology included a discomfort questionnaire and performance measures. The independent variables were the work-rest schedule (60-minute work/10-minute rest, 30-minute work/5-minute rest, and 15-minute work/micro breaks) and the type of task (data entry and a mental arithmetic task). The results were analysed using multiple analysis of variance followed by separate analyses. The 15/micro schedule resulted in significantly lower discomfort in the neck, lower back, and chest than the other schedules for data entry task. The 30/5 schedule followed by 15/micro schedule resulted in the lowest eyestrain and blurred vision. Discomfort in the elbow and arm was the lowest with the 15/micro schedule for the mental arithmetic task. The 15/micro schedule resulted in the highest speed, accuracy, and performance for both of the tasks, compared with the 60/10 and 30/5 schedules. The data entry task resulted in significantly increased speed, accuracy, and performance, and lower shoulder and chest discomfort than the mental arithmetic task.

Effects of Adjustable Sit-stand VDT Workstations on Workers' Musculoskeletal Discomfort, Alertness and Performance

“…The micro break effect 20) may be reflected in this trend, since the use of sit-stand workstations plays a role in providing workers with opportunities for body movements when workers change their sitting/standing postures. Sit-stand workstations therefore seem to have the possibility to keep up workers' performance.…”

Stretch breaks in the work setting improve flexibility and grip strength and reduce musculoskeletal complaints

“…Implementing the SBP increased the AW group's grip strength both on the DS and the NDS, but it had no effect on the SW group. In other studies, increasing the frequency of pause breaks improved the workers' accuracy and/or speed during computer use (Balci & Aghazadeh, 2003;Kopardekar & Mital, 1994). Restrictions on workers' pause breaks during computer use have been identified as risk factors for musculoskeletal symptoms and injuries (Bergqvist, Wolgast, Nilsson, & Voss, 1995a, 1995b.…”

“…WHP programs include employee education, modified workspace designs, adjusting work habits and promoting exercise, stretches and short rest breaks. The physiologic benefits of a stretch break program include reduced intervertebral disc pressure, increased blood flow, reductions in muscle lactic acid and increased attention (Andersen et al, 2012;Balci & Aghazadeh, 2003;Cheema et al, 2013;Varatharajan et al, 2014;Zebis et al, 2011).…”

Risk Factors Affecting Subjective Symptoms of Fatigue Due to the Environment of High School Students’ Computer Workstation in the Republic of Korea

“…Accordingly, one needs to take a rest at least once an hour during long durations of computer use in order to feel the least amount of fatigue 29,30) . Some studies recommended computer users to take a rest every 15 minutes 31) . The correlation analysis showed there were positive correlations among subordinate domains of subjective symptoms of fatigue and the total score subjective symptoms of fatigue, and there were negative correlations among the total score of subjective symptoms of fatigue and computer workstation feature.…”