title: Active pauses induce more variable electromyographic pattern of the trapezius muscle activity during computer work.
abstract: The aim of this laboratory study was to evaluate effects of active and passive pauses and investigate the distribution of the trapezius surface electromyographic (SEMG) activity during computer mouse work. Twelve healthy male subjects performed four sessions of computer work for 10 min in one day, with passive (relax) and active (30% maximum voluntary contraction of shoulder elevation) pauses given every 2 min at two different work paces (low/high). Bipolar SEMG from four parts of the trapezius muscle was recorded. The relative rest time was higher for the lower parts compared with the upper of the trapezius (p<0.01). The centroid of exposure variation analysis (EVA) along the time axis was lower during the computer work with active pause compared with passive one (p<0.05). The results of this study revealed (i) lower rest time for the upper parts of trapezius compared with the lower parts, in line with previous clinical findings, (ii) active pauses contributed to a more variable muscle activity pattern during computer work that might have functional implications with respect to work-related musculoskeletal disorders.
authors.affiliation: Laboratory for Ergonomics and Work-related Disorders, Center for Sensory-Motor Interaction, Department of Health Science and Technology, Aalborg University, Fredrik Bajers Vej 7 D-3, 9220 Aalborg East, Denmark.
authors.forename: Afshin
authors.initials: A
authors.lastname: Samani
authors.forename: Andreas
authors.initials: A
authors.lastname: Holtermann
authors.forename: Karen
authors.initials: K
authors.lastname: Søgaard
authors.forename: Pascal
authors.initials: P
authors.lastname: Madeleine
mesh_terms: D004576:Electromyography / Q000379:methods*; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D015203:Reproducibility of Results; D012146:Rest / Q000502:physiology*; D012680:Sensitivity and Specificity; D012785:Shoulder Joint / Q000502:physiology*; D015443:Word Processing; D055815:Young Adult