A Cross-Country Comparison of Short-and Long-Term Effects of an Ergonomic Intervention on Musculoskeletal Discomfort, Eyestrain and Psychosocial Stress in VDT Operators: Selected Aspects of the International Project

Video Display Operator Complaints: A 10-Year Follow-Up of Visual Fatigue and Refractive Disorders

Visual fatigue and discomfort are very common complaints for video display operators (VDTs). The aim of our study was to study work-related visual symptoms in relation to refractive disorders and psychosocial factors in 3054 public employees by way of follow-ups for 10 years with periodic medical examinations with eye evaluation in the period 2000-2009. Factors related to visual fatigue were evaluated in the follow-up using generalized equation estimation. Visual fatigue was very common in VDT operators (64.03%). During the follow-up, no relationship between visual fatigue and age, sex, seniority of work, visual acuity and refractory disorders was found. Visual fatigue was significantly associated with anxiety perception in a dose-related matter (odds ratio (OR) 7.40, confidence interval (CI) 95% 1.77-31.3), psychosocial factors (OR 1.03, CI 95% 1.01-1.07), use of lenses (OR 1.34, CI 95% 1.09-1.64) and time of VDT usage (OR 1.27, CI 95% 1.04-1.53). This study confirmed that visual fatigue is common in VDT users and is related to anxiety perception, time of VDT usage, use of lenses and stress. No relationship was found between visual fatigue and refractory disorders or visual acuity.

Workplace interventions to improve sitting posture: A systematic review

PURPOSE

Evaluate the effectiveness of workplace interventions to improve sitting posture of workers that spend long periods of time seated at a visual display terminal.

METHODS

A systematic review of randomised controlled trials, non-randomised controlled trials and single-group intervention trials featuring workplace interventions with pre- and follow-up measurements of sitting posture was conducted (registered in PROSPERO, CRD#42015027648). Nine databases were searched for studies available between January 2005 and February 2016.

RESULTS

2519 articles were screened with 12 studies meeting the inclusion criteria. The included studies featured various ergonomic workplace interventions and comprised 4 randomised controlled trial (n=457), 2 non-randomised controlled trials (n=416) and 6 single-group intervention trials (n=328). Due to clinical and methodological heterogeneity, pooling of data was not completed and a narrative summary of findings was developed using the Grading of Recommendations Assessment Development and Evaluation (GRADE) framework. The evidence for four review outcomes was assessed with medium to large positive improvements obtained for the majority of studies investigating changes to gross sitting posture, whereas mixed findings were obtained for more specific local segment assessments of sitting posture. The overall evidence quality for all review outcomes were identified as either 'low' or 'very low'.

CONCLUSION

There is evidence which is limited in quality to indicate that ergonomic workplace interventions can improve gross sitting posture. More high quality research across a range of intervention types is required with longer follow-up durations and more advanced methods to assess sitting posture with greater frequency and less bias.

Fatigue and pain related to internet usage among university students

[Purpose] This study was performed to assess fatigue and pain levels related to internet usage among university students. The dominant regions of fatigue and pain in the body were examined, as well as differences in fatigue and pain levels among students. [Subjects and Methods] The study used a descriptive survey and a convenience sample of 378 students from a single university. The data were collected from January 1 to June 31, 2015. Fatigue and pain levels were measured using a visual analog scale. [Results] The average reported by the participants 4.7 and 3.7 levels of fatigue and pain, respectively. The regions with the highest fatigue scores were the eyes, followed by the neck, and shoulders. The regions with the highest pain scores were the neck, followed by the shoulders, and the waist. The results show that participants’ fatigue and pain levels depended on the duration of their internet use per day. [Conclusion] These findings indicate that control of internet usage time is needed to maintain the well-being of university students who use the internet.

Scanning through the pain: ergonomic considerations for performing echocardiography of animals

Work-related musculoskeletal disorders (MSD) are a common problem among sonographers, with prevalence in human sonographers of 80-90%. However, this problem appears to be largely neglected in the veterinary literature. Awareness of MSDs, ergonomic redesign, workplace management, and physical self-care are components to reducing the risk of developing MSDs. Work-place redesign and alterations in work flow management are discussed, and a template for a more ergonomically favorable echocardiogram table is provided.

A replicated field intervention study evaluating the impact of a highly adjustable chair and office ergonomics training on visual symptoms

OBJECTIVE

Examine the effects of two office ergonomics interventions in reducing visual symptoms at a private sector worksite.

METHODS

A quasi-experimental study design evaluated the effects of a highly adjustable chair with office ergonomics training intervention (CWT group) and the training only (TO group) compared with no intervention (CO group). Data collection occurred 2 and 1 month(s) pre-intervention and 2, 6 and 12 months post-intervention. During each data collection period, a work environment and health questionnaire (covariates) and daily health diary (outcomes) were completed. Multilevel statistical models tested hypotheses.

RESULTS

Both the training only intervention (p<0.001) and the chair with training intervention (p=0.01) reduced visual symptoms after 12 months.

CONCLUSION

The office ergonomics training alone and coupled with a highly adjustable chair reduced visual symptoms. In replicating results from a public sector worksite at a private sector worksite the external validity of the interventions is strengthened, thus broadening its generalizability.

A field intervention examining the impact of an office ergonomics training and a highly adjustable chair on visual symptoms in a public sector organization

OBJECTIVE

Examine the effect of a multi-component office ergonomics intervention on visual symptom reductions.

METHODS

Office workers were assigned to either a group receiving a highly adjustable chair with office ergonomics training (CWT), a training-only group (TO) or a control group (C). A work environment and health questionnaire was administered 2 and 1 month(s) pre-intervention and 3, 6, and 12 months post-intervention. Multi-level statistical models tested hypotheses.

RESULTS

The CWT intervention lowered daily visual symptoms (p < 0.01) post-intervention. The TO group did not significantly differ from the control group. The CWT group differed significantly from the TO group (p = 0.01) post-intervention.

CONCLUSION

Workers who received a highly adjustable chair and office ergonomics training had reduced visual symptoms and the effect was maintained through twelve months post-intervention. The lack of a training-only group effect supports implementing training in conjunction with the highly adjustable chair to reduce visual symptoms.

Will musculoskeletal and visual stress change when Visual Display Unit (VDU) operators move from small offices to an ergonomically optimized office landscape?

This study investigated the effect of moving from small offices to a landscape environment for 19 Visual Display Unit (VDU) operators at Alcatel Denmark AS. The operators reported significantly improved lighting condition and glare situation. Further, visual discomfort was also significantly reduced on a Visual Analogue Scale (VAS). There was no significant correlation between lighting condition and visual discomfort neither in the small offices nor in the office landscape. However, visual discomfort correlated significantly with glare in small offices i.e. more glare is related to more visual discomfort. This correlation disappeared after the lighting system in the office landscape had been improved. There was also a significant correlation between glare and itching of the eyes as well as blurred vision in the small offices, i.e. more glare more visual symptoms. Experience of pain was found to reduce the subjective assessment of work capacity during VDU tasks. There was a significant correlation between visual discomfort and reduced work capacity in small offices and in the office landscape. When moving from the small offices to the office landscape, there was a significant reduction in headache as well as back pain. No significant changes in pain intensity in the neck, shoulder, forearm, and wrist/hand were observed. The pain levels in different body areas were significantly correlated with subjective assessment of reduced work capacity in small offices and in the office landscape. By careful design and construction of an office landscape with regard to lighting and visual conditions, transfer from small offices may be acceptable from a visual-ergonomic point of view.

Systematic review of the role of occupational health and safety interventions in the prevention of upper extremity musculoskeletal symptoms, signs, disorders, injuries, claims and lost time

BACKGROUND

Little is known about the most effective occupational health and safety (OHS) interventions to reduce upper extremity musculoskeletal disorders (MSDs) and injuries.

METHODS

A systematic review used a best evidence synthesis approach to address the question: "do occupational health and safety interventions have an effect on upper extremity musculoskeletal symptoms, signs, disorders, injuries, claims and lost time?"

RESULTS

The search identified 36 studies of sufficient methodological quality to be included in data extraction and evidence synthesis. Overall, a mixed level of evidence was found for OHS interventions. Levels of evidence for interventions associated with positive effects were: Moderate evidence for arm supports; and Limited evidence for ergonomics training plus workstation adjustments, new chair and rest breaks. Levels of evidence for interventions associated with "no effect" were: Strong evidence for workstation adjustment alone; Moderate evidence for biofeedback training and job stress management training; and Limited evidence for cognitive behavioral training. No interventions were associated with "negative effects".

CONCLUSION

It is difficult to make strong evidenced-based recommendations about what practitioners should do to prevent or manage upper extremity MSDs. There is a paucity of high quality OHS interventions evaluating upper extremity MSDs and none focused on traumatic injury outcomes or workplace mandated pre-placement screening exams. We recommend that worksites not engage in OHS activities that include only workstation adjustments. However, when combined with ergonomics training, there is limited evidence that workstation adjustments are beneficial. A practice to consider is using arm supports to reduce upper extremity MSDs.

Computer work and musculoskeletal disorders of the neck and upper extremity: a systematic review

BACKGROUND

This review examines the evidence for an association between computer work and neck and upper extremity disorders (except carpal tunnel syndrome).

METHODS

A systematic critical review of studies of computer work and musculoskeletal disorders verified by a physical examination was performed.

RESULTS

A total of 22 studies (26 articles) fulfilled the inclusion criteria. Results show limited evidence for a causal relationship between computer work per se, computer mouse and keyboard time related to a diagnosis of wrist tendonitis, and for an association between computer mouse time and forearm disorders. Limited evidence was also found for a causal relationship between computer work per se and computer mouse time related to tension neck syndrome, but the evidence for keyboard time was insufficient. Insufficient evidence was found for an association between other musculoskeletal diagnoses of the neck and upper extremities, including shoulder tendonitis and epicondylitis, and any aspect of computer work.

CONCLUSIONS

There is limited epidemiological evidence for an association between aspects of computer work and some of the clinical diagnoses studied. None of the evidence was considered as moderate or strong and there is a need for more and better documentation.

Prognostic factors for the effects of two interventions for work-related neck-shoulder complaints: myofeedback training and ergonomic counselling

AIM

To explore prognostic factors for the effects of two interventions (myofeedback training in combination with ergonomic counselling (Mfb/EC) and ergonomic counselling alone (EC)) on discomfort and disability in work-related neck-shoulder complaints.

METHODS

Thirty-six females completed the interventions. Discomfort and disability were assessed at baseline, immediately after the intervention, and at 3-month follow-up. Potential sociodemographic and psychological prognostic factors were assessed using questionnaires. Data were analysed using multiple regression and general linear modelling.

RESULTS

Changes in discomfort were best predicted by baseline discomfort levels. Changes in disability were predicted by baseline disability levels, patient profile, and coping strategy 'ignoring sensations'. A significant difference between the Mfb/EC and EC group was found for coping strategy 'ignoring sensations', which appeared to be a predictor for changes in disability at 3-month follow-up in the Mfb/EC group only.

CONCLUSIONS

Subjects with high levels of initial discomfort and disability and specific psychological patient profiles benefit most from interventions. Myofeedback training contributes a specific quality to those who ignore pain sensations.

Musculoskeletal, visual and psychosocial stress in VDU operators after moving to an ergonomically designed office landscape

This study investigated the effect of moving from single occupancy offices to a landscape environment. Thirty-four Visual Display Unit (VDU) operators reported significantly worsened condition of lighting and glare in addition to increased visual discomfort. For visual discomfort, the difference with 95% confidence interval was 10.7 (1.9-19.5) Visual Analog Scale (VAS) as group mean value. The most reasonable explanation for these results may be that the operators were glared from high luminance from the windows, when the Venetian blinds were not properly used. Glare was significantly correlated with visual discomfort, rs=0.35. Both illuminance and luminance in the work area, and contrast reduction on the VDU screen were in line with recommendations from CIE for VDU work. In a regression analysis, the visual discomfort explained 53% of the variance in the neck and shoulder pain. In the office landscape, the eye blink rate during habitual VDU work was recorded for 12 randomly selected operators from the 34 participants. A marked drop in eye blink rate during VDU work was found when this was compared to "easy conversation" (VDU work, mean=9.7 blinks per minute; "easy conversation," mean=21.4 blinks per minute). Participants reported many of the organizational and psychosocial conditions and work factors worse when landscape office was compared to single occupancy office. These factors may have influenced the musculoskeletal pain. However, the pain level was still low at 6 years and not significantly different when compared with the start of the study period, except for a small but significant increase in shoulder pain. In this study, visual discomfort is clearly associated with pain in the neck and shoulder area.

Changes in cognitive-behavioral factors and muscle activation patterns after interventions for work-related neck-shoulder complaints: relations with discomfort and disability

OBJECTIVES

Knowledge regarding the working mechanism of an intervention is essential for obtaining a better understanding of the intervention and contributes to optimize its outcome. This study aimed at investigating whether changes in cognitive-behavioral factors and muscle activation patterns after myofeedback training and ergonomic counseling were associated with outcome, in subjects with work-related musculoskeletal neck-shoulder complaints.

METHODS

Seventy-nine symptomatic subjects received either myofeedback with ergonomic counseling (Mfb/EC) or ergonomic counseling alone (EC). Outcome measures discomfort and disability, and process factors catastrophizing, pain control, fear-avoidance beliefs, and muscle activation patterns were assessed at baseline, after the interventions (T0), and at 3 months follow-up (T3). Mixed modeling techniques were used for analysis.

RESULTS

Outcome in terms of discomfort and disability was generally comparable between both interventions. Catastrophizing was significantly reduced and fear-avoidance beliefs about work slightly increased after the interventions, but no consistent changes in muscle activation patterns were observed. Changes in discomfort were especially associated with changes in catastrophizing at T0 and T3, but R(2) was low (<0.14). Reduced catastrophizing at T0 and T3, and also reduced fear-avoidance beliefs about work at T3, were related to reduced disability (R(2) between 0.30 and 0.40). No differences between the two intervention groups were observed.

CONCLUSIONS

Intervention effects were generally non-specific and findings suggested that cognitive-behavioral factors underlie the outcome of these interventions rather than changes in muscle activation patterns. Emphasizing these factors during therapy may increase the beneficial outcome of occupational interventions.

Effects of ambulant myofeedback training and ergonomic counselling in female computer workers with work-related neck-shoulder complaints: a randomized controlled trial

OBJECTIVE

To investigate the effects of ambulant myofeedback training including ergonomic counselling (Mfb) and ergonomic counselling alone (EC), on work-related neck-shoulder pain and disability.

METHODS

Seventy-nine female computer workers reporting neck-shoulder complaints were randomly assigned to Mfb or EC and received four weeks of intervention. Pain intensity in neck, shoulders, and upper back, and pain disability, were measured at baseline, immediately after intervention, and at three and six months follow-up.

RESULTS

Pain intensity and disability had significantly decreased immediately after four weeks Mfb or EC, and the effects remained at follow up. No differences were observed between the Mfb and EC group for outcome and subjects in both intervention groups showed comparable chances for improvement in pain intensity and disability.

CONCLUSIONS

Pain intensity and disability significantly reduced after both interventions and this effect remained at follow-up. No differences were observed between the two intervention groups.