Ewa Wigaeus Tornqvist

Self-reported working conditions of VDU operators and associations with musculoskeletal symptoms : a cross-sectional study focussing on gender differences

The aim of the present study was to describe working conditions and the prevalence of musculoskeletal symptoms among male and female VDU operators, and to assess associations between work-related physical and psychosocial exposures and neckand upper limb symptoms by gender. The study population comprised a variety of occupations from both private and public sectors. Data on physical and psychosocial exposures were collected by questionnaires, as were data on musculoskeletal symptoms. Univariate associations between exposures and symptoms affecting the neck and upper limbs were estimated by calculating the prevalence ratios with 95% confidence intervals. We also assessed the potential excess odds ratio attributable to interaction between gender and, one by one, exposure variable. Women (n ¼ 785) used the computer on average 3.9 h/day and men (n ¼ 498) 3.6. Variation of different worktask s was lower among females than among males. Nineteen per cent of the women and 12% of the men did >3 h of continued computer work without breaks (>10 min) at least twice a week. Twice as many women as men experienced high job strain (high demands and low decision latitude). A higher proportion of women than men reported symptoms X3 days the preceding month from the upper body, irrespective of body region. For many of the studied exposures the prevalence of symptoms in one or several body regions was increased with increasing exposure, indicating exposureresponse relationships. Duration of computer work was associated with symptoms among both men and women. Only among men, duration of work with a non-keyboard computer input device was associated with symptoms. Only among women, job strain was associated with symptoms. Time pressure was associated with higher prevalence of symptoms among women. Among men, time pressure was associated with lower prevalence of symptoms. Thus, the associations differed between the genders. Women experienced higher prevalence of symptoms than men in all body regions and they were more often exposed to physical and psychosocial conditions that in previous studies have been considered harmful, than men. Relevance to industry Work-related exposures and the associations between these factors and musculoskeletal symptoms among VDU operators differed in some respect between men and women. This should be considered in intervention programs. The results from this study gives further support to the advice that duration of computer work, time pressure and job strain

Self-Reported Reduced Productivity Due to Musculoskeletal Symptoms: Associations with Workplace and Individual Factors Among White-Collar Computer Users

The aim was to assess whether self-reported reduced productivity occurred in computer users due to musculoskeletal symptoms and the association to workplace, symptom, and individual factors. The study group consisted of 1283 computer users from different occupations, of whom 498 were men and 785 were women. Reduced productivity was self-assessed by two questions addressing if and how much productivity was reduced the previous month due to musculoskeletal symptoms. There were 63 women (8.0%) and 42 men (8.4%) of the total study group who reported reduced productivity due to musculoskeletal symptoms. The mean magnitude of the reduction was 15% for women and 13% for men. This outcome was weakly associated with computer mouse position and task and symptom persistence for both men and women. For women, work demands, computer problems, and being divorced/separated were also associated with reduced productivity. Although limited by problems of subjectivity of self-report and the possibility of significant underreporting, these results suggest that a variety of interventions may serve to decrease the impact of musculoskeletal disorders in the workplace.

The influence on seeking care because of neck and shoulder disorders from work-related exposures

The aim of this study was to assess the influence of work-related physical and psychosocial factors on seeking care for neck or shoulder disorders among men and women in a general working population. The study population comprised gainfully employed (>17 hours per week) men and women in the municipality of Norrtälje, altogether 392 cases and 1,511 controls. Cases were defined as persons seeking care because of neck or shoulder disorders by any caregiver in the region. The study began in 1994 and continued to 1997. We assessed physical and psychosocial exposures by questionnaires and interviews. The pattern of seeking care for neck or shoulder disorders differed between men and women. Among men, work with vibrating tools [relative risk (RR) = 1.6], not having a fixed salary (RR = 1.9), and low demands in relation to competence (RR = 1.5) were the strongest risk indicators obtained in analyses stratified for age and previous symptoms. Among women, repetitive hand or finger movements (RR = 1.6), constrained sitting (RR = 1.6), not having a fixed salary (RR = 2.0), and solitary work (RR = 1.8) were the strongest risk indicators. A large proportion of the general population was exposed to several of these moderately harmful conditions, and their concomitant effect may explain the high incidence of neck and shoulder disorders in the general working population.

The impact of working technique on physical loads—an exposure profile among newspaper editors

About 35 % of the working population in Sweden report that computer use accounts for 50% or more of their total working hours. Among this population approximately 40% of the women and 25% of the men experienced symptoms in the neck and/or upper extremities at least once a week during the preceding 3 month. The overall aim of the studies underlying this thesis was to explore possible associations between working technique and perceived exertion, comfort, biomechanical and psychosocial strain as well as neck and upper extremity symptoms among computer users. Specific research questions addressed were a) Whether working technique was associated with muscle activity, wrist positions and forces applied to the computer mouse, respectively? b) Whether working technique was associated with psychological demands, emotional stress and perceived muscle tension, respectively? c) Whether there were associations between self-rated perceived comfort and observations of workplace layout and between self-rated perceived exertion and working postures. d) Whether working technique perceived exertion and comfort was associated with neck and upper extremity symptoms. The results showed that subjects classified as having a good working technique worked with less muscular load in the forearm (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. Subjects who reported high psychological demands and perceived muscular tension, respectively, used poorer working technique than subjects who did not perceive this conditions (demands, p=0.03, muscular tension, p=0.02). Moreover, the concordance between ratings of comfort and observations of workplace layout was reasonably good concerning the working chair and the keyboard and good regarding the computer screen and the input device. The concordance between ratings of perceived exertion and observations of working postures indicated good agreement for all measured body locations. This applies to the group that rated poor comfort and high exertion. Regarding the group that rated good comfort and low exertion ratings must be supplemented with observations. Furthermore, the results revealed that high perceived exertion and low comfort were related to an increased incidence of neck, and upper extremity symptoms, while poor working technique was not associated with such a risk. It is concluded that working technique is associated with both biomechanical and psychological strain while no associations could be seen between working technique and the incidence of neck and upper extremity symptoms. Furthermore, high perceived exertion and low comfort are associated with a higher incidence of neck and upper extremity symptoms.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.

Symptoms and clinical findings from the musculoskeletal system among operators at a call centre in Sweden--a 10-month follow-up study.

The musculoskeletal health among 57 operators at 1 call centre in Sweden was studied with 10 monthly follow-ups, parallel to a reference group of 1,226 professional computer users in other occupations. Operators at this call centre were more symptom-loaded than the other professional computer users in spite of their younger age and shorter exposure to computer work. Symptoms were long-lasting or recurrent. Muscle tenderness and nerve affections in the neck- shoulder region were the most common specific findings and diagnoses at medical examination of incident symptom cases. More extensive studies should be done on the working conditions and health status among call centre workers.

Perceived exertion, comfort and working technique in professional computer users and associations with the incidence of neck and upper extremity symptoms

BackgroundThe aim of this study was to investigate whether perceived exertion, perceived comfort and working technique is associated with the incidence of neck and upper extremity symptoms among professional computer users.MethodsAt baseline a self-administered questionnaire was distributed to 853 participants from 46 different work sites (382 men and 471 women) who, at baseline, had been free from neck and upper extremity symptoms during the preceding month. Work-related exposures, individual factors, and symptoms from the neck and upper extremities were assessed. Observations of working technique were performed by ergonomists using an ergonomic checklist. Incidence data were collected by means of 10 monthly questionnaires, asking for information on the occurrence of neck, shoulder and arm/hand symptoms. Perceived exertion was rated on a modified Borg RPE scale ranging from 0 (very, very light) to 14 (very, very strenuous). Perceived comfort was rated on a 9-point scale ranging from -4 (very, very poor) to +4 (very, very good) in relation to the chair, computer screen, keyboard, and computer mouse.ResultsThe median follow up time was 10.3 months. The incidence of symptoms from the neck, shoulders and arm/hands were 50, 24 and 34 cases per 100 person years, respectively.Higher perceived exertion in the neck, shoulder or arm/hands was associated with an increased risk of developing symptoms in the corresponding body region. Moreover, a dose-response relationship between the level of exertion and the risk of developing symptoms was recorded for all three regions. There was an association between low comfort and an increased risk for neck symptoms, but not for shoulder and arm/hand symptoms, although a trend towards such an association (not statistically significant) could be seen. Working technique was, in this study, not associated with the risk of developing symptoms in any of the investigated body regions.ConclusionThere was a strong association between high perceived exertion and the development of neck, shoulder, and arm/hand symptoms. Moreover, there was an association between poor perceived comfort and neck pain. Surveillance of computer users may include perceived exertion and comfort to target individuals at risk for neck and upper extremity symptoms.

Reliability of a Questionnaire and an Ergonomic Checklist for Assessing Working Conditions and Health at Call Centres

Background. The purpose was to study the test-retest reliability and internal consistency of questions in aquestionnaire concerning working conditions and health and the inter-rater reliability of observations andmeasurements according to an ergonomic checklist. Method. Fifty-seven operators participated in a retestquestionnaire and 58 operators participated in an inter-observer test. Results. The questions had fair to good or higher reliability in 142 of the total of 312. Twenty-seven of the total of 44 variables in the ergonomicchecklist were classified as having fair to good or higher reliability. Conclusions. About half of the questionshad fair to good or higher reliability and can be recommended for further analyses. The majority of variablesin the ergonomic checklist were classified as having fair to good or higher reliability. Low reliability does notnecessarily indicate that the reliability of the test, per se, is low but may signify that the conditions measuredvary over time or that the answers are aggregated in one part of the scale.

Working conditions in a selected sample of call centre companies in Sweden

Background. Call centres (CCs) are among the most rapidly growing forms of workplaces in Sweden. The purpose of the study was to describe and compare working conditions between operators at internal and external CC companies and work tasks of different complexity. Method. A questionnaire was answered by 1183 operators, 848 women and 335 men, from 28 different CCs. The questionnaire covered background factors, employment, working hours and remuneration, call logging and monitoring, duties, computer work and workplace design during the previous month. Results. Operators at external companies and operators with low-complexity work tasks were younger, more often employed by the hour and worked on a varying roster. They spent longer time on customer calls and had less varied tasks. Additional remuneration, call logging and monitoring were more common at external companies and among operators with low-complexity work tasks. Conclusion. The working conditions varied between internal and external CCs. There was also a variation in working conditions between work tasks of different complexity. There were aspects of supervision style and organization of work at CCs, especially at external ones and those with low-complexity tasks that could introduce stress and lack of well being among the staff.

Incidence and risk factors for symptoms from the eyes among professional computer users

Personal computers are used by a majority of the working population in their professions. Little is known about risk-factors for incident symptoms from the eyes among professional computer users. The aim was to study the incidence and risk-factors for symptoms from the eyes among professional computer users.This study is a part of a comprehensive prospective follow-up study of factors associated with the incidence of symptoms among professional computer users. 1531 computer users of different professions at 46 companies were invited, whereof 1283 answered a baseline questionnaire (498 men; 785 women) and 1246 at least one of 10 monthly follow-up questionnaires. The computer work-station and equipment were generally of a good standard. The majority used CRT displays.During the follow-up period 329 subjects reported eye symptoms. The overall incidence rate in the whole study group was 0.38 per person-year, 0.23 in the subgroup of subjects who were symptom free at baseline and 1.06 among subjects who reported eye symptoms at baseline. In the bivariate analyses significant associations were found with all explanatory variables, except BMI. The reduced multivariate model showed significant associations with extended computer work, visual discomfort (dose-response), eye symptoms at baseline (higher risk), sex (women=higher risk) and nicotine use.The incidence of eye problems among professional computer users is high and related to both individual and work-related factors.