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- Lindegård Andersson, Agneta, 1955, et al.
(författare)
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The impact of working technique on physical loads - an exposure profile among newspaper editors.
- 2003
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Ingår i: Ergonomics. - : Informa UK Limited. - 0014-0139 .- 1366-5847. ; 46:6, s. 598-615
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the possible associations between working technique, sex, symptoms and level of physical load in VDU-work. A study group of 32 employees in the editing department of a daily newspaper answered a questionnaire, about physical working conditions and symptoms from the neck and the upper extremities. Muscular load, wrist positions and computer mouse forces were measured. Working technique was assessed from an observation protocol for computer work. In addition ratings of perceived exertion and overall comfort were collected. The results showed that subjects classified as having a good working technique worked with less muscular load in the forearm (extensor carpi ulnaris p=0.03) and in the trapezius muscle on the mouse operating side (p=0.02) compared to subjects classified as having a poor working technique. Moreover there were no differences in gap frequency (number of episodes when muscle activity is below 2.5% of a reference contraction) or muscular rest (total duration of gaps) between the two working technique groups. Women in this study used more force (mean force p=0.006, peak force p=0.02) expressed as % MVC than the men when operating the computer mouse. No major differences were shown in muscular load, wrist postures, perceived exertion or perceived comfort between men and women or between cases and symptom free subjects. In conclusion a good working technique was associated with reduced muscular load in the forearm muscles and in the trapezius muscle on the mouse operating side. Moreover women used more force (mean force and peak force) than men when operating the click button (left button) of the computer mouse.
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| 2. |
- Wahlström, Jens, 1972, et al.
(författare)
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Perceived muscular tension, emotional stress, psychological demands and physical load during VDU work.
- 2003
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Ingår i: International archives of occupational and environmental health. - 0340-0131. ; 76:8, s. 584-90
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVES. The aim of this study was to investigate whether perceived muscular tension, psychological demands and emotional stress were associated with physical load or working technique during visual display unit (VDU) work. METHODS. Subjects (28 women and 29 men) from two different organisations volunteered to participate in the study. The study design was cross-sectional, and the data were assessed when the subjects performed their usual work tasks at their usual work place. Multivariate linear and logistic regression models were used to investigate possible associations. The different outcome variables were: median muscle activity and muscular rest in the trapezius muscle bilaterally, wrist movements and working technique. The different explanatory variables were: perceived muscular tension (binary), emotional stress (binary), psychological demands (binary), organisation (binary) and gender (binary). Age (continuous) and present musculoskeletal pain (binary) were also controlled for in the multivariate models. Electromyography (EMG) and electrogoniometers were used to assess the physical load, and the data collection time was 15 min. An ergonomic checklist was used to assess working technique, i.e. work with lifted shoulders. RESULTS. Subjects who perceived muscular tension at least a few times per week the month before the measurements were made worked with higher muscle activity [expressed as per cent of a reference voluntary electrical activity (% RVE)] in the trapezius muscle bilaterally (5% RVE, P=0.05). High emotional stress during the measurement was associated with higher muscle activity in the trapezius muscle on the side not operating the computer mouse (8% RVE, P=0.006). Subjects who reported high levels of emotional stress worked more often with lifted shoulders (odds ratio 6.0, 95% CI 1.2-28.9). However, when present musculoskeletal pain was included in the multivariate model the odds ratio for high emotional stress decreased to 4.5 (95% CI 0.9-23.2). CONCLUSIONS. Perceived muscular tension and emotional stress were associated with physical load, in terms of muscle activity in the trapezius muscles, during VDU work in ordinary occupational settings.
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