Attention-related muscle activity in different body regions during VDU work with minimal physical activity.
The purpose of this study was to characterize regional variation in task-irrelevant muscle activity. Surface EMG was recorded at 20 different muscle sites during a complex choice-reaction task. Up to ten muscle sites were recorded in parallel and always including the upper trapezius muscles. The experimental setting was designed to minimize the physical activity while performing a VDU-based task demanding continuing attention. Consequently, the label 'attention-related muscle activity' has been adopted. The presence of this activity varied between subjects and between the different muscle sites. It tended to decrease in a caudal direction and to be low in the muscles of the extremities, with the exception of the extensor muscles of the hand and foot. Attention-related activity was prevalent in the frontalis and upper trapezius muscles. This result is discussed with respect to a potentially harmful health effect of task-irrelevant muscle activity.
Waersted
M
M
Department of Physiology, National Institute of Occupational Health, Oslo, Norway.
Westgaard
R H
RH
D000328:Adult; D016288:Computer Terminals; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000502:physiology*; D011930:Reaction Time; D013647:Task Performance and Analysis