Abstract:
The aim of this research was to investigate the effects of different types of activities during rest-breaks interventions on neck and shoulder muscular activity, posture, muscular discomfort and productivity in VDU operators performing prolonged computer work. Systematic review was conducted to evaluate the available evidence of rest breaks on musculoskeletal health, productivity and muscle activity. Test-retest reliability was conducted to examine the reliability of EMG normalization in VDU operators with neck and shoulder symptoms. RCT was carried out among symptomatic VDU operators randomly assigned to stretching, dynamic movement, and reference group. Subjects performed 60-minute typing task and received 3-minute breaks of each 20-minute work. Root mean square (RMS) and median frequency (MF) were calculated for neck and shoulder muscle activity. Muscular discomfort was measured by Borg CR 10 scale. Productivity was measured by word counting. Neck and shoulder postures were obtained from the 3D motion analysis system.
Evidence supported that the rest-break interventions had beneficial effect to reduce musculoskeletal discomfort. MVIC-normalization method could be measured with sufficient reliability for neck and shoulder muscles in symptomatic VDU operators. Three types of activity during breaks showed favorable effect on neck and shoulder muscle activity, postures, and productivity, and positive effect on muscular discomfort for symptomatic VDU operators.
