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Muscular rest and gap frequency as EMG measures of physical exposure: the impact of work tasks and individual related factors

Nordander, Catarina LU orcid ; Hansson, Gert-Åke LU ; Rylander, Lars LU orcid ; Asterland, P ; Bystrom, J U ; Ohlsson, Kerstina LU ; Balogh, Istvan LU and Skerfving, Staffan LU (2000) In Ergonomics 43(11). p.1904-1919
Abstract
Owing to an orderly recruitment of motor units, low threshold type I fibres are presumed to be vulnerable in contractions of long duration. To study load on these fibres muscular rest was registered as the time fraction of electromyographic (EMG) activity below a threshold. Moreover, the frequency of periods with muscular rest, EMG gaps, was derived, since a low gap frequency has been shown to be a risk factor for musculoskeletal disorders. Trapezius EMG was registered in 24 female hospital cleaners, 21 female office workers and 13 male office workers during one working day. Cleaners have a high risk of neck/shoulder pain and had much less muscular rest than office workers measured as a percentage of total registered time (median value =... (More)
Owing to an orderly recruitment of motor units, low threshold type I fibres are presumed to be vulnerable in contractions of long duration. To study load on these fibres muscular rest was registered as the time fraction of electromyographic (EMG) activity below a threshold. Moreover, the frequency of periods with muscular rest, EMG gaps, was derived, since a low gap frequency has been shown to be a risk factor for musculoskeletal disorders. Trapezius EMG was registered in 24 female hospital cleaners, 21 female office workers and 13 male office workers during one working day. Cleaners have a high risk of neck/shoulder pain and had much less muscular rest than office workers measured as a percentage of total registered time (median value = 1.5%, range = 0.2-13% vs. median value = 12%, range = 0.0-32%, respectively). Gap frequency showed no difference between the two occupational groups. Both measures displayed a wide inter-individual variation. For the cleaners, some of the variance was explained by body mass index (BMI) and age, with lower values of muscular rest for older subjects with a high BMI. Among the office workers, low values of muscular rest and a high gap frequency were registered in subjects with a low subjective muscular tension tendency. Gender, strength, smoking, job strain, employment time and musculoskeletal symptoms had no impact on either EMG measure. (Less)
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organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Ergonomics
volume
43
issue
11
pages
1904 - 1919
publisher
Taylor & Francis
external identifiers
  • pmid:11105979
  • scopus:0033750345
  • pmid:11105979
ISSN
0014-0139
DOI
10.1080/00140130050174536
language
English
LU publication?
yes
id
fd5e990a-5810-4739-b232-da492ff676e5 (old id 1118438)
date added to LUP
2016-04-01 12:36:37
date last changed
2022-01-27 07:28:21
@article{fd5e990a-5810-4739-b232-da492ff676e5,
  abstract     = {{Owing to an orderly recruitment of motor units, low threshold type I fibres are presumed to be vulnerable in contractions of long duration. To study load on these fibres muscular rest was registered as the time fraction of electromyographic (EMG) activity below a threshold. Moreover, the frequency of periods with muscular rest, EMG gaps, was derived, since a low gap frequency has been shown to be a risk factor for musculoskeletal disorders. Trapezius EMG was registered in 24 female hospital cleaners, 21 female office workers and 13 male office workers during one working day. Cleaners have a high risk of neck/shoulder pain and had much less muscular rest than office workers measured as a percentage of total registered time (median value = 1.5%, range = 0.2-13% vs. median value = 12%, range = 0.0-32%, respectively). Gap frequency showed no difference between the two occupational groups. Both measures displayed a wide inter-individual variation. For the cleaners, some of the variance was explained by body mass index (BMI) and age, with lower values of muscular rest for older subjects with a high BMI. Among the office workers, low values of muscular rest and a high gap frequency were registered in subjects with a low subjective muscular tension tendency. Gender, strength, smoking, job strain, employment time and musculoskeletal symptoms had no impact on either EMG measure.}},
  author       = {{Nordander, Catarina and Hansson, Gert-Åke and Rylander, Lars and Asterland, P and Bystrom, J U and Ohlsson, Kerstina and Balogh, Istvan and Skerfving, Staffan}},
  issn         = {{0014-0139}},
  language     = {{eng}},
  number       = {{11}},
  pages        = {{1904--1919}},
  publisher    = {{Taylor & Francis}},
  series       = {{Ergonomics}},
  title        = {{Muscular rest and gap frequency as EMG measures of physical exposure: the impact of work tasks and individual related factors}},
  url          = {{http://dx.doi.org/10.1080/00140130050174536}},
  doi          = {{10.1080/00140130050174536}},
  volume       = {{43}},
  year         = {{2000}},
}