Musculoskeletal disorders and visual strain in intensive data processing workers

Effects of computer use on upper limb musculoskeletal disorders and function in academicians

Objectives. This study aimed to investigate the effects of academician's demographic characteristics and computer usage habits on upper limb musculoskeletal disorders (MSDs) and function. Methods. A cross-sectional observational study was conducted with 100 academicians. Data were collected using questionnaires, which included the patient-rated wrist evaluation questionnaire - Turkish version (PRWE-T), the Cornell musculoskeletal discomfort questionnaire - Turkish version (CMDQ-T), the upper extremity functional index - Turkish version (UEFI-T), demographic characteristics and average daily computer usage time. Results. A low-level significant correlation was found between the age of the individuals and the CMDQ-T forearm (p = 0.044; r = 0.202) and CMDQ-T wrist (p = 0.001; r = 0.337) scores. Women had higher CMDQ-T neck scores and lower UEFI-T scores than men (p < 0.05). Academicians who used computers for 6 h a day or more had higher PRWE-T and CMDQ-T neck, shoulder, upper arm and forearm scores, and had a lower UEFI-T score (p < 0.05). Conclusion. Neck, shoulder, upper arm and forearm symptoms were higher and upper extremity function was impaired in academicians who used computers for 6 h a day or more. Besides, gender and age were associated with upper limb MSDs and function, but occupation duration did not affect those outcomes in academicians.

Wrist redundancy management during pointing tasks remains stable over time and in presence of a visuomotor perturbation

Pointing at a screen using wrist and forearm movements is a kinematically redundant task, and the Central Nervous System seems to manage this redundancy by using a simplifying strategy, named Donders' Law for the wrist. In this work we investigated (1) whether this simplifying approach is stable over time and (2) whether a visuomotor perturbation provided in the task space influences the strategy used to solve the redundancy problem. We conducted two experiments asking participants to perform the same pointing task in four different days (first experiment), and providing a visual perturbation, i.e. a visuomotor rotation to the controlled cursor (second experiment), while recording their wrist and forearm rotations. Results showed that the participant-specific wrist redundancy management (described by the Donders' surfaces) (1) neither changes over time (2) nor varies when a visuomotor perturbation is provided in the task space.

TFOS Lifestyle: Impact of the digital environment on the ocular surface

Eye strain when performing tasks reliant on a digital environment can cause discomfort, affecting productivity and quality of life. Digital eye strain (the preferred terminology) was defined as "the development or exacerbation of recurrent ocular symptoms and/or signs related specifically to digital device screen viewing". Digital eye strain prevalence of up to 97% has been reported, due to no previously agreed definition/diagnostic criteria and limitations of current questionnaires which fail to differentiate such symptoms from those arising from non-digital tasks. Objective signs such as blink rate or critical flicker frequency changes are not 'diagnostic' of digital eye strain nor validated as sensitive. The mechanisms attributed to ocular surface disease exacerbation are mainly reduced blink rate and completeness, partial/uncorrected refractive error and/or underlying binocular vision anomalies, together with the cognitive demand of the task and differences in position, size, brightness and glare compared to an equivalent non-digital task. In general, interventions are not well established; patients experiencing digital eye strain should be provided with a full refractive correction for the appropriate working distances. Improving blinking, optimizing the work environment and encouraging regular breaks may help. Based on current, best evidence, blue-light blocking interventions do not appear to be an effective management strategy. More and larger clinical trials are needed to assess artificial tear effectiveness for relieving digital eye strain, particularly comparing different constituents; a systematic review within the report identified use of secretagogues and warm compress/humidity goggles/ambient humidifiers as promising strategies, along with nutritional supplementation (such as omega-3 fatty acid supplementation and berry extracts).

Eye Habits Affect the Prevalence of Asthenopia in Patients with Myopia

Purpose

This study aims to explore the risk factors of asthenopia in the myopic population.

Methods

In this cross-sectional study, myopia patients were inquired about their eye habits and were requested to complete an asthenopia questionnaire and ocular examinations. Age, gender, occupation, anisometropia, eye care education, weekly outdoor activity time, duration of continuous near work, daily screen time, dry eye, near phoria, and binocular accommodative facility were calculated using the Student's test-test, Mann Whitney U test, and Pearson's chi-square test. Spherical equivalents and astigmatism were calculated using a generalized estimating equation. Binary logistic regression was performed on factors with a p-value <0.05.

Results

Of the 65 myopic patients, 57% showed asthenopia, 52% experienced blurry vision, 37% felt their eyes hurt or sore, and 28% felt tired when performing close work. Asthenopia patients were older than patients without asthenopia (Z = −2.887, p=0.004). Daily screen time, continuous near-work time, eye care education, and dry eye were positively correlated with asthenopia (χ² = 8.64, p=0.003; χ2 = 13.873, p < 0.001, χ2 = 9.643, p=0.002; χ2 = 7.035, p=0.008). After eliminating collinearity, eye care education and continuous near-work time were identified as independent risk factors of asthenopia, with odds ratios of 0.115 and 4.227, respectively.

Conclusion

This study shows that receiving eye care education from schools and hospitals and limiting near-work duration to less than 45 minutes per session could reduce the occurrence of asthenopia in myopic patients. This approach may be a more economical and convenient way for myopic people to relieve asthenopia.

The Impact of Excessive Use of Digital Devices During the Pandemic of Corona Virus Disease (COVID-19) Among Saudi Arabia Population

Background:

A substantial increase in using digital devices was observed among the population due to staying at home as a result of the quarantine during the coronavirus pandemic. Consequently, ocular symptoms appeared due to spending several hours of screen time per day.

Objective:

The current study aimed to assess the impact of excessive use of digital devices during the pandemic of coronavirus among the Saudi population.

Methods:

A community-based cross-sectional study was carried out from November 2020 to January 2021 among the Saudi population. Data were collected by using Ocular Surface Disease Index (OSDI) questionnaires for the assessment of symptoms related to dry eye and their effect on vision. A logistic regression model was used to evaluate the association between the risk factors and the symptoms of dry eye. SPSS 22nd edition was used, any p-value <0.05 was considered significant.

Results:

Out of 1573 participants, 93.8% used mobile, 42.4% experienced uncomfortable sensitivity to the light. There were 49.15% of the participants who showed that none of the time they felt blurry vision, 54.8% did not report double vision, and 30.5% who felt a headache recently after quarantine. About 48% of the participants did not have any ocular symptoms, while 52% had dry eye symptoms (mild 22.3%, moderate 13.7%, and severe 15.9%). When the logistic regression model of risk factors associated with severe symptoms of dry eye was applied, wearing a contact lens was the most significant variable (p<0.0001).

Conclusion:

Dry eye symptoms increased during the quarantine, which indicated that the digital device users need to learn more about the preventive measures from practitioners in eye healthcare. More studies are warranted to assess the impact of digital device usage on all age groups starting from children up to the elderly population.

The Effect of Lockdown Due to the COVID-19 Pandemic on Digital Eye Strain Symptoms Among the General Population: A Cross-Sectional Survey

Repetitive prolonged use of digital devices without regular breaks has detrimental effects on ocular health and quality of vision. Individuals with chronic eye problems and refractive errors are at higher risk of developing digital eye strain (DES). Correction of refractive errors, adopting healthy practices will reduce its risk. The survey examined the effect of prolonged lockdown on the development and increased severity of digital eye strain (DES) symptoms among the general population. An online survey was conducted in March 2020 on social media platforms in Jordan. Data from 1,460 responders were analyzed. About half of the respondents were between 30–49 years, 28.4% were retired, 21% had chronic systemic illness, and 23% reported chronic eye problems. A rise in the use of digital devices during lockdown was reported by 957 participants, with 33% of them used digital devices more than 4 h a day. The most common symptoms before and during lockdown were headache and neck / shoulder pain have the highest associations (X² = 280.0, 271.3, df = 4, p < 0.001 respectively). Female gender, existence of chronic eye problems and systemic diseases, and duration of using digital devices were found to be statistically significant factors associated with increasing severity of eye symptoms during lockdown. Not taking enough regular breaks from digital devices showed significant association with blurred vision at distance and near (X² = 13.03, 10.74, df = 4, P = 0.011, 0.03, respectively). People with chronic eye problems and increased time using devices during lockdown developed new eye complaints three times more than before the lockdown and males were two times more likely than females to have more severe eye symptoms.

Computer vision syndrome in presbyopic digital device workers and progressive lens design

PURPOSE

To estimate the prevalence of computer vision syndrome (CVS) in presbyopic digital device workers using two ophthalmic progressive lens designs during the working day, and to analyse the association of CVS with sociodemographic, occupational, digital device exposure and refractive factors.

METHODS

This time series, quasi-experimental design study included 69 presbyopic digital device workers (age range: 46-69 years; mean ± SD = 54.7 ± 5.0). All used desktop computers at their workplace. Progressive addition lenses (PALs) and occupational lenses were used for three months each. CVS was measured with the CVS-Q^© questionnaire before intervention (baseline) and at 1 week, 1 month and 3 months after wearing the lenses. A multivariate logistic regression model was used to identify the factors that were associated with an improved CVS-Q^© score.

RESULTS

37.7% of the subjects were female and 78.3% were ametropes; 65.2% had advanced presbyopia. 56.2% used digital devices at work >6 h day^-1 . The prevalence of CVS at baseline, after wearing PALs for three months and after three months of occupational lens wear was 68.1%, 33.3% and 18.8%, respectively. The mean CVS-Q^© score was lower with occupational lenses than with PALs (p = 0.001). 40.6% of the digital device workers improved their CVS-Q^© score ≥2 points with the occupational lenses. Ametropes were less likely than emmetropes to improve with occupational lenses (OR = 0.27, p = 0.05). 89.8% of the sample workers were satisfied or very satisfied with the occupational lenses and 71% were similarly satisfied with the PALs. 73.9% chose the occupational lenses as their first choice of lens for digital device use, compared with 17.4% for PALs.

CONCLUSIONS

Computer vision syndrome is reduced in presbyopic desktop computer workers wearing occupational lenses compared with PALs, especially in emmetropes.

Musculoskeletal Pain and Non-Classroom Teaching in Times of the COVID-19 Pandemic: Analysis of the Impact on Students from Two Spanish Universities

The lockdown, due to the coronavirus, has led to a change in lifestyle and physical activity in Spanish university students. The objective of this study was to analyze the prevalence of musculoskeletal pain and changes in physical activity and self-perceived stress in the student bodies of two Spanish Universities during the lockdown. A cross-sectional study was carried out in a sample of 1198 students (70.6% women). The main instruments used for measuring were the Standardized Kuorinka Modified Nordic Questionnaire and the Perceived stress scale (the questionnaire regarding the practice of physical activity). A reduction in the prevalence of musculoskeletal pain (p < 0.001) was identified in the sample of men and women, an increase (12.5%) in the frequency of carrying out physical activity from moderate to frequent, and the preference for strength training (15.1%), especially among women, was identified. All of this may be taken into account by health institutions when implementing measures to encourage physical activity in both suitable amounts and types, which improves the quality of life of the students.

Prevalence of neck/shoulder pain among public hospital workers in China and its associated factors: a cross-sectional study

Studies have reported that neck and/or shoulder pain (NSP) was prevalent and a non-ignorable occupational health problem in healthcare providers. Considering data deficiency on NSP, we aimed to investigate the prevalence and sick leave absence of NSP among public hospital workers in Shandong, China and to explore the associated factors for chronic NSP. A self-administered questionnaire including the Dutch Musculoskeletal Questionnaire and Modified Nordic Musculoskeletal Questionnaire was filled in by 30,520 hospital workers in 37 hospitals selected randomly from among all public hospitals of Shandong, China. The 12-month prevalence of NSP lasting for at least 3 months and sick leave absence due to NSP among 29,547 public hospital workers was 15.6% and 11.4%, respectively, most frequently reported in tertiary hospital workers (27.4% and 18.9%) and clinicians (19.1% and 15.2%). Log-binomial regression analysis revealed that chronic NSP was significantly associated with hospital level, employment position, contract/temporary employment status (vs. permanent), workload (long work hours per week), ergonomic factors (bending the neck forward for long periods of time, twisting the neck for long periods of time) and computer-related factors (prolonged computer-using time daily, the keyboard too close to the edge of the desk).

A Wearable Device Based on a Fiber Bragg Grating Sensor for Low Back Movements Monitoring

Low back pain (LBP) is one of the musculoskeletal disorders that most affects workers. Among others, one of the working categories which mainly experiences such disease are video terminal workers. As it causes exploitation of the National Health Service and absenteeism in workplaces, LBP constitutes a relevant socio-economic burden. In such a scenario, a prompt detection of wrong seating postures can be useful to prevent the occurrence of this disorder. To date, many tools capable of monitoring the spinal range of motions (ROMs) are marketed, but most of them are unusable in working environments due to their bulkiness, discomfort and invasiveness. In the last decades, fiber optic sensors have made their mark allowing the creation of light and compact wearable systems. In this study, a novel wearable device embedding a Fiber Bragg Grating sensor for the detection of lumbar flexion-extensions (F/E) in seated subjects is proposed. At first, the manufacturing process of the sensing element was shown together with its mechanical characterization, that shows linear response to strain with a high correlation coefficient (R² > 0.99) and a sensitivity value (S_ε) of 0.20 nm∙mε⁻¹. Then, the capability of the wearable device in measuring F/E in the sagittal body plane was experimentally assessed on a small population of volunteers, using a Motion Capture system (MoCap) as gold standard showing good ability of the system to match the lumbar F/E trend in time. Additionally, the lumbar ROMs were evaluated in terms of intervertebral lumbar distances (ΔdL3−L1) and angles, exhibiting moderate to good agreement with the MoCap outputs (the maximum Mean Absolute Error obtained is ~16% in detecting ΔdL3−L1). The proposed wearable device is the first attempt for the development of FBG-based wearable systems for workers’ safety monitoring.

Occupational Health Needs and Predicted Well-Being in Office Workers Undergoing Web-Based Health Promotion Training: Cross-Sectional Study

BACKGROUND

Office workers face workplace-related health issues, including stress and back pain, resulting in considerable cost to businesses and health care systems. Workplace health promotion attempts to prevent these health issues, and the internet can be used to deliver workplace health promotion interventions to office workers. Data were provided by Fitbase GmbH, a German company, which specializes in workplace health promotion via the internet (Web-based health). The Web-based health intervention allowed workers to focus on different health categories by using information modules (reading health information) and/or completing practical exercises (guided, interactive health tutorials).

OBJECTIVE

This study aimed to identify the extent to which office workers have workplace-related health issues, assess whether office workers who differ in their health focus also differ in their improved well-being, and assess whether completing practical exercises is associated with improved well-being compared with reading information modules.

METHODS

Fitbase GmbH collected data for the period of February 2016 to May 2017 from health insurance employees undergoing Web-based health training in Hamburg, Germany. The data consisted of a needs assessment examining health issues faced by office workers, a wellness questionnaire regarding one's perception of the Web-based health intervention, and activity logs of information modules and practical exercises completed. Through logistic regression, we determined associations between improved well-being from Web-based health training and differences in a worker's health focus and a worker's preferred intervention method.

RESULTS

Nearly half of the office workers had chronic back pain (1532/3354) and felt tense or irritated (1680/3348). Over four-fifth (645/766) of the office workers indicated that the Web-based health training improved their well-being (P<.001). Office workers who preferred practical exercises compared with information modules had 2.22 times greater odds of reporting improved well-being from the Web-based health intervention (P=.01; 95% CI 1.20-4.11). Office workers with a focus on practical exercises for back health had higher odds of improved well-being compared with other health foci. Office workers focused on practical exercises for back pain had at least two times the odds of having their well-being improved from the Web-based health intervention compared with those focused on stress management (P<.001), mindfulness (P=.02), stress management/mindfulness (P=.005), and eye health (P=.003). No particular health focus was associated with improved well-being for the information modules.

CONCLUSIONS

Office workers frequently report having back pain and stress. A focus on Web-based health training via practical exercises and practical exercises for back health predict an improvement in office workers' reported well-being.

Prevalence of Computer Vision Syndrome and Its Relationship with Ergonomic and Individual Factors in Presbyopic VDT Workers Using Progressive Addition Lenses

This cross-sectional study estimated computer vision syndrome (CVS) prevalence and analysed its relationship with video display terminal (VDT) exposure, as well as sociodemographic, refractive, environmental, and ergonomic characteristics in 109 presbyopic VDT workers wearing progressive addition lenses (PALs). Usual spectacles were measured with a lens analyser, and subjective refraction was performed by an optometrist. CVS was measured with the CVS-Q©. VDT exposure was collected. Ergonomic evaluations were conducted in a normal working posture looking at the screen. Air temperature and relative humidity were measured (thermohygrometer), and illumination was measured (luxmeter). Descriptive analysis and differences in CVS prevalence, as a function of the explanatory variables, were performed (chi-square test). Multivariate logistic regression was used to identify factors associated with CVS (OR and 95% CI). The mean age was 54.0 ± 4.8 years, and 43.1% were women. The mean hours of VDT use at work was 6.5 ± 1.3 hours/day. The prevalence of CVS was 74.3%. CVS was significantly associated with women (OR 3.40; 95% CI, 1.12–10.33), non-neutral neck posture (OR 3.27; 95% CI, 1.03–10.41) and altered workplace lighting (OR 3.64; 95% CI, 1.22–10.81). Providing training and information to workers regarding the importance of adequate lighting and ergonomic postures during VDT use is advised to decrease CVS and increase workplace quality of life.

Prevalence of Work Related Psychological and Musculoskeletal Problems among Business Process Outsourcing Workers

Background

Musculoskeletal disorders are mainly caused due to static work which includes sitting and standing for a prolonged time and sedentary unhealthy lifestyle lead to physical related health problems and may affect one’s psychosocial, physical and mental health. The purpose of the study is find out the prevalence of work related psychological and musculoskeletal problems among business process outsourcing workers.

Methods

An observational study in which 100 participants were included according to the inclusion and exclusion criteria with 50 males and 50 females. Participants with age of 20-35 years and minimum 1 year of work experience with alternative working shifts were selected for the study. Stress and burnout questionnaire, Cornell musculoskeletal discomfort questionnaire and body mass index calculator were used as an outcome measure in the study.

Results

Musculoskeletal problem was higher in neck region and wrist region and 2% participants had burnout stress syndrome.

Conclusion

High prevalence of musculoskeletal disorder found over neck region, hip/buttocks, wrist and low back and 2% of the population had burnout stress syndrome and no significance correlating body mass index and musculoskeletal disorder.

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.

Discomfort glare and psychological stress during computer work: subjective responses and associations between neck pain and trapezius muscle blood flow

PURPOSE

Exposure to additional environmental stress during computer work, such as visual and psychological demands, is associated with increased eye and neck discomfort, altered moods, and reduced well-being. The aim of this study is to elucidate further how subjective responses in healthy, young females with normal binocular vision are affected by glare and psychological stress during computer work, and to investigate possible associations between trapezius muscle blood flow and neck pain development.

METHODS

43 females participated in a laboratory experiment with a within-subject design. Four 10-min computer work conditions with exposure to different stressors were performed at an ergonomically optimal workstation, under the following series of conditions: no additional stress, visual stress (induced as direct glare from a large glare source), psychological stress, and combined visual and psychological stress. Before and immediately after each computer work condition, questionnaires regarding different visual and eye symptoms, neck and shoulder symptoms, positive and negative state moods, perceived task difficulty, and perceived ambient lighting were completed. Associations between neck pain and trapezius muscle blood flow were also investigated.

RESULTS

Exposure to direct glare induced greater development of visual/eye symptoms and discomfort, while psychological stress exposure made participants feel more negative and stressed. The perception of work lighting during glare exposure was closely related to perceived stress, and associations between visual discomfort and eyestrain, and neck pain were observed in all conditions. Furthermore, participants with high trapezius muscle blood flow overall reported more neck pain, independent of exposure.

CONCLUSIONS

Exposure to visual and psychological stresses during computer work affects the development of symptoms and negative moods in healthy, young females with normal binocular vision, but in different ways. The results also demonstrate the complex interactions involved in symptom development and lighting appraisal during computer work. When optimizing computer workstations, the complexity of the field must be taken into account, and several factors, including visual conditions, must be considered carefully.

Blind working time in visual display terminal users

OBJECTIVES

Blind working (BW) time (time during which vision is not required), the interblink interval (IBI), and subjective symptoms were investigated in workers using visual display terminals (VDTs).

SUBJECTS AND METHODS

To investigate BW time, 10 VDT users were instructed to close their eyes when this did not interfere with their work. They were video recorded for 60 minutes using a webcam attached to the display on which they were engaged in regular data input tasks, and BW time was measured. The values of the IBI during the final 20 minutes of the BW experiment and during the final 20 minutes of normal working without BW were compared. A questionnaire was administered to investigate subjective symptoms using a visual analogue scale.

RESULTS

The total BW time during the final 20-minute period was 20.6-121.0 seconds (1.7%-10.1%). The mean IBI of 5.5 ± 4.5 seconds during the BW experiment was not significantly different from that of 6.2 ± 5.6 seconds during normal working, and the mean of three IBIs immediately after BW during the BW experiment was 2.7 ± 1.0 seconds, significantly shorter than the 6.2 ± 5.6 seconds during normal working. Dry eye, ocular fatigue, and blurred vision during normal working improved when subjects were engaged in BW.

CONCLUSIONS

VDT users could engage in BW during VDT work, the IBI was shorter immediately after BW, and subjective symptoms improved. These results suggest that BW may provide a more effective measure for the management of VDT working time.

Ergonomic interventions for preventing work-related musculoskeletal disorders of the upper limb and neck among office workers

BACKGROUND

Work-related upper limb and neck musculoskeletal disorders (MSDs) are one of the most common occupational disorders worldwide. Studies have shown that the percentage of office workers that suffer from MSDs ranges from 20 to 60 per cent. The direct and indirect costs of work-related upper limb MSDs have been reported to be high in Europe, Australia, and the United States. Although ergonomic interventions are likely to reduce the risk of office workers developing work-related upper limb and neck MSDs, the evidence is unclear. This is an update of a Cochrane Review which was last published in 2012.

OBJECTIVES

To assess the effects of physical, cognitive and organisational ergonomic interventions, or combinations of those interventions for the prevention of work-related upper limb and neck MSDs among office workers.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, CINAHL, Web of Science (Science Citation Index), SPORTDiscus, Embase, the US Centers for Disease Control and Prevention, the National Institute for Occupational Safety and Health database, and the World Health Organization's International Clinical Trials Registry Platform, to 10 October 2018.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of ergonomic interventions for preventing work-related upper limb or neck MSDs (or both) among office workers. We only included studies where the baseline prevalence of MSDs of the upper limb or neck, or both, was less than 25%.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias. We included studies with relevant data that we judged to be sufficiently homogeneous regarding the interventions and outcomes in the meta-analysis. We assessed the overall quality of the evidence for each comparison using the GRADE approach.

MAIN RESULTS

We included 15 RCTs (2165 workers). We judged one study to have a low risk of bias and the remaining 14 studies to have a high risk of bias due to small numbers of participants and the potential for selection bias.Physical ergonomic interventionsThere is inconsistent evidence for arm supports and alternative computer mouse designs. There is moderate-quality evidence that an arm support with an alternative computer mouse (two studies) reduced the incidence of neck or shoulder MSDs (risk ratio (RR) 0.52; 95% confidence interval (CI) 0.27 to 0.99), but not the incidence of right upper limb MSDs (RR 0.73; 95% CI 0.32 to 1.66); and low-quality evidence that this intervention reduced neck or shoulder discomfort (standardised mean difference (SMD) -0.41; 95% CI -0.69 to -0.12) and right upper limb discomfort (SMD -0.34; 95% CI -0.63 to -0.06).There is moderate-quality evidence that the incidence of neck or shoulder and right upper limb disorders were not considerably reduced when comparing an alternative computer mouse and a conventional mouse (two studies; neck or shoulder: RR 0.62; 95% CI 0.19 to 2.00; right upper limb: RR 0.91; 95% CI 0.48 to 1.72), and also when comparing an arm support with a conventional mouse and a conventional mouse alone (two studies) (neck or shoulder: RR 0.91; 95% CI 0.12 to 6.98; right upper limb: RR 1.07; 95% CI 0.58 to 1.96).Workstation adjustment (one study) and sit-stand desks (one study) did not have an effect on upper limb pain or discomfort, compared to no intervention.Organisational ergonomic interventionsThere is very low-quality evidence that supplementary breaks (two studies) reduce discomfort of the neck (MD -0.25; 95% CI -0.40 to -0.11), right shoulder or upper arm (MD -0.33; 95% CI -0.46 to -0.19), and right forearm or wrist or hand (MD -0.18; 95% CI -0.29 to -0.08) among data entry workers.Training in ergonomic interventionsThere is low to very low-quality evidence in five studies that participatory and active training interventions may or may not prevent work-related MSDs of the upper limb or neck or both.Multifaceted ergonomic interventionsFor multifaceted interventions there is one study (very low-quality evidence) that showed no effect on any of the six upper limb pain outcomes measured in that study.

AUTHORS' CONCLUSIONS

We found inconsistent evidence that the use of an arm support or an alternative mouse may or may not reduce the incidence of neck or shoulder MSDs. For other physical ergonomic interventions there is no evidence of an effect. For organisational interventions, in the form of supplementary breaks, there is very low-quality evidence of an effect on upper limb discomfort. For training and multifaceted interventions there is no evidence of an effect on upper limb pain or discomfort. Further high-quality studies are needed to determine the effectiveness of these interventions among office workers.

A model for predicting the risk of musculoskeletal disorders among computer professionals

Objective. This study aimed to develop a model for predicting the risk of musculoskeletal disorders among computer professionals. Materials and methods. A preliminary study with a modified Nordic musculoskeletal questionnaire was conducted to identify the risk in different body parts of the professionals during their work. A discrete postural evaluation of the dynamic postures involved in the work was assessed using rapid upper limb assessment. Postural, physiological and work-related factors were considered as attributes of the model. The model was developed using various machine learning algorithms, and was then tested and validated. Results. The postural factor of the computer professionals was found to be significantly (p < 0.01) correlated with the musculoskeletal disorders. Results of the logistic regression analysis showed that physiological and work-related factors were also significantly (p < 0.05) associated with musculoskeletal disorders. The Random Forest algorithm and Naïve Bayes Classifier predicted the risk of musculoskeletal disorders with the highest accuracy (81.25%). Conclusion. Postural, physiological and work-related factors contribute to the development of musculoskeletal disorders. The Random Forest algorithm or Naïve Bayes Classifier model developed based on these factors could be used to accurately predict the risk of musculoskeletal disorders among computer professionals at any instance of time, during their work.

The Prevalence and Associations of Peripheral Retinopathy: Baseline Study of Guangzhou Office Computer Workers

Purpose

To determine the prevalence of peripheral retinopathy and its associated risk factors among a sample of Guangzhou office computer workers.

Methods

A cross-sectional study of Guangzhou Chinese computer workstations and operators in different departments and units of the Guangzhou Power Supply Bureau, China, in 2016. Peripheral retinopathy was recorded and analyzed using a scanning laser ophthalmoscope (SLO; Optos, Daytona, United Kingdom) and slit-lamp microscopy combined with a three-mirror contact lens.

Results

The 1934 eyes of 967 subjects (513 females and 454 males) were included in this study. In total, 79.1% of the eyes were myopic in workers aged 20–29 years, 72.9% in workers aged 30–39 years, 62.2% in workers aged 40–49 years, and 43.4% in workers aged 50–59 years (p < 0.001). Most eyes had optic nerve crescents (81.3%). Various peripheral degenerations were found: 7 eyes (0.4%) had microcystoid degeneration, 40 (2.1%) had peripheral pigmentary degeneration, 87 (4.5%) had lattice degeneration, and 4 (0.2%) had snail-track degeneration. Nineteen (1.0%) eyes had paving-stone degeneration, 11 (0.6%) eyes had a retinal hole or tear, and 16 (0.8%) eyes had chorioretinal degeneration. Multivariate regression confirmed that greater axial length (OR: 1.18 (1.03, 1.35), p=0.012) and more serious spherical equivalent (OR: 0.82 (0.77, 0.88), p < 0.001) were significant risk factors for peripheral retinal changes.

Conclusion

Peripheral retinal degenerative changes were found in a larger proportion of younger computer workers than older ones. Myopia is occurring in younger and younger people, accompanied by peripheral retinal degeneration.

Visual and psychological stress during computer work in healthy, young females-physiological responses

Purpose

Among computer workers, visual complaints, and neck pain are highly prevalent. This study explores how occupational simulated stressors during computer work, like glare and psychosocial stress, affect physiological responses in young females with normal vision.

Methods

The study was a within-subject laboratory experiment with a counterbalanced, repeated design. Forty-three females performed four 10-min computer-work sessions with different stress exposures: (1) minimal stress; (2) visual stress (direct glare); (3) psychological stress; and (4) combined visual and psychological stress. Muscle activity and muscle blood flow in trapezius, muscle blood flow in orbicularis oculi, heart rate, blood pressure, blink rate and postural angles were continuously recorded. Immediately after each computer-work session, fixation disparity was measured and a questionnaire regarding perceived workstation lighting and stress was completed.

Results

Exposure to direct glare resulted in increased trapezius muscle blood flow, increased blink rate, and forward bending of the head. Psychological stress induced a transient increase in trapezius muscle activity and a more forward-bent posture. Bending forward towards the computer screen was correlated with higher productivity (reading speed), indicating a concentration or stress response. Forward bent posture was also associated with changes in fixation disparity. Furthermore, during computer work per se, trapezius muscle activity and blood flow, orbicularis oculi muscle blood flow, and heart rate were increased compared to rest.

Conclusions

Exposure to glare and psychological stress during computer work were shown to influence the trapezius muscle, posture, and blink rate in young, healthy females with normal binocular vision, but in different ways. Accordingly, both visual and psychological factors must be taken into account when optimizing computer workstations to reduce physiological responses that may cause excessive eyestrain and musculoskeletal load.

Individual and work-related risk factors for musculoskeletal pain among computer workers in Nigeria

We investigated the prevalence of musculoskeletal pain (MSP) and the association of 1-month prevalence with individual and work-related factors among commercial typists in Enugu. Participants responded to a questionnaire about occurrences of MSP and a 75.6% (242/320) response rate was achieved. Prevalence was summarized in frequencies and percentages while associations between MSPs and risk factors were explored using chi-square. MSP was most common in the low back (58.3%), and low back pain limited 51.7% from activities between 1 and 30 days. Advancing age was significantly associated with MSP in the low back (x² = 19.885; p = .001), neck (x² = 28.309; p < .001), shoulder (x² = 13.122; p = .011), but not wrist/hand (p = .075). Working 1-5 years in this job was associated with increasing prevalence of MSP in all body regions studied. Lesser job control was associated with increased prevalence of wrist/hand pain. Prevalence of MSDs among computer operators in Enugu, Nigeria, is high and highlights the importance of workplace intervention.

Neck/shoulder discomfort due to visually demanding experimental near work is influenced by previous neck pain, task duration, astigmatism, internal eye discomfort and accommodation

Visually demanding near work can cause eye discomfort, and eye and neck/shoulder discomfort during, e.g., computer work are associated. To investigate direct effects of experimental near work on eye and neck/shoulder discomfort, 33 individuals with chronic neck pain and 33 healthy control subjects performed a visual task four times using four different trial lenses (referred to as four different viewing conditions), and they rated eye and neck/shoulder discomfort at baseline and after each task. Since symptoms of eye discomfort may differ depending on the underlying cause, two categories were used; internal eye discomfort, such as ache and strain, that may be caused by accommodative or vergence stress; and external eye discomfort, such as burning and smarting, that may be caused by dry-eye disorders. The cumulative performance time (reflected in the temporal order of the tasks), astigmatism, accommodation response and concurrent symptoms of internal eye discomfort all aggravated neck/shoulder discomfort, but there was no significant effect of external eye discomfort. There was also an interaction effect between the temporal order and internal eye discomfort: participants with a greater mean increase in internal eye discomfort also developed more neck/shoulder discomfort with time. Since moderate musculoskeletal symptoms are a risk factor for more severe symptoms, it is important to ensure a good visual environment in occupations involving visually demanding near work.

Effects of Dual Monitor Computer Work Versus Laptop Work on Cervical Muscular and Proprioceptive Characteristics of Males and Females

OBJECTIVE

The effects of performing a 90-minute computer task with a laptop versus a dual monitor desktop workstation were investigated in healthy young male and female adults.

BACKGROUND

Work-related musculoskeletal disorders are common among computer (especially female) users. Laptops have surpassed desktop computer sales, and working with multiple monitors has also become popular. However, few studies have provided objective evidence on how they affect the musculoskeletal system in both genders.

METHODS

Twenty-seven healthy participants (mean age = 24.6 years; 13 males) completed a 90-minute computer task while using a laptop or dual monitor (DualMon) desktop. Electromyography (EMG) from eight upper body muscles and visual strain were measured throughout the task. Neck proprioception was tested before and after the computer task using a head-repositioning test. EMG amplitude (root mean square [RMS]), variability (coefficients of variation [CV]), and normalized mutual information (NMI) were computed.

RESULTS

Visual strain ( p < .01) and right upper trapezius RMS ( p = .03) increased significantly over time regardless of workstation. Right cervical erector spinae RMS and cervical NMI were smaller, while degrees of overshoot (mean = 4.15°) and end position error (mean = 1.26°) were larger in DualMon regardless of time. Effects on muscle activity were more pronounced in males, whereas effects on proprioception were more pronounced in females.

CONCLUSION

Results suggest that compared to laptop, DualMon work is effective in reducing cervical muscle activity, dissociating cervical connectivity, and maintaining more typical neck repositioning patterns, suggesting some health-protective effects.

APPLICATION

This evidence could be considered when deciding on computer workstation designs.

Risk factors and visual fatigue of baggage X-ray security screeners: a structural equation modelling analysis

This study identified the risk factors influencing visual fatigue in baggage X-ray security screeners and estimated the strength of correlations between those factors and visual fatigue using structural equation modelling approach. Two hundred and five X-ray security screeners participated in a questionnaire survey. The result showed that satisfaction with the VDT's physical features and the work environment conditions were negatively correlated with the intensity of visual fatigue, whereas job stress and job burnout had direct positive influences. The path coefficient between the image quality of VDT and visual fatigue was not significant. The total effects of job burnout, job stress, the VDT's physical features and the work environment conditions on visual fatigue were 0.471, 0.469, -0.268 and -0.251 respectively. These findings indicated that both extrinsic factors relating to VDT and workplace environment and psychological factors including job burnout and job stress should be considered in the workplace design and work organisation of security screening tasks to reduce screeners' visual fatigue. Practitioner Summary: This study identified the risk factors influencing visual fatigue in baggage X-ray security screeners and estimated the strength of correlations between those factors and visual fatigue. The findings were of great importance to the workplace design and the work organisation of security screening tasks to reduce screeners' visual fatigue.

Visual and ocular effects from the use of flat-panel displays

AIM

To evaluate the prevalence of eye symptoms in a non-presbyopic population of video display unit (VDU) users with flat-panel displays.

METHODS

One hundred and sixteen VDU users with flat-panel display from an urban population participated in the study; their ages ranging from 20 to 34y. There were 60 females and 56 males. An eye examination to rule out the presence of significant uncorrected refractive errors, general binocular dysfunctions and eye conditions was carried out. In order to determine and quantify the type and nature of eye symptoms, participants were asked to answer written questionnaire and the results were grouped by gender, age and number of hours a day spent using a VDU.

RESULTS

Seventy-two percent of participants reported eye symptoms related to VDU use. Eye symptoms from moderate-to-severe were found in 23% of participants. The main symptom was moderate-to-severe tired eyes (14%); followed by sensitivity to bright lights (12%), blurred vision at far distances (10%), eyestrain or dry eye or irritated or burning eyes (9%), difficulty in refocusing from one distance to another or headache (8%) and blurred vision at near or intermediate distances (<4%). Eye symptoms were greater among females (P=0.005) and increased with VDU use, markedly above 6h spent using a VDU in a typical day (P=0.01).

CONCLUSION

Significant eye symptoms relate to VDU use often occur and should not be underestimated. The increasing use of electronic devices with flat-panel display should prompt users to take appropriate measures to prevent or to relieve the eye symptoms arising from their use.

MUSCULOSKELETAL SYMPTOMS AMONG BANK OFFICE WORKERS: TWO YEARS FOLLOW-UP SURVEY

Work-related musculoskeletal disorders (WMSDs) represent one of the leading causes of occupational injury and disability in the developed and industrially developing countries. The economic loss due to such disorders is high and affects not only the individual but also the organization and the society as a whole. The goal of this study was to determine the prevalence rate of musculoskeletal symptoms (MSS) among employees of the bank office sectors and also identifying majors factors associated with symptoms in the study population in the city of Kerman, Iran. Between 2008 and 2009, 324 (224 male and 100 female) bank office workers was interviewed individually in a private one-on-one interview. A modified version of the nordic musculoskeletal questionnaire (NMQ) and cornell musculoskeletal discomfort questionnaire (CMDQ) translated into Farsi by the author was used in this study. The response rate of questionnaire was 68% (152 male and 61 female). The highest prevalence of symptoms were found for male and female upper back, female Hip/Buttocks and neck, and female lower back (62%). The highest prevalence of symptoms was found for female neck, upper back and lower back. Finding indicated that females have been experiencing more complaints than males. The prevalence of MSS among targeted population occurred in high rate.

A reliable and valid questionnaire was developed to measure computer vision syndrome at the workplace

OBJECTIVES

To design and validate a questionnaire to measure visual symptoms related to exposure to computers in the workplace.

STUDY DESIGN AND SETTING

Our computer vision syndrome questionnaire (CVS-Q) was based on a literature review and validated through discussion with experts and performance of a pretest, pilot test, and retest. Content validity was evaluated by occupational health, optometry, and ophthalmology experts. Rasch analysis was used in the psychometric evaluation of the questionnaire. Criterion validity was determined by calculating the sensitivity and specificity, receiver operator characteristic curve, and cutoff point. Test-retest repeatability was tested using the intraclass correlation coefficient (ICC) and concordance by Cohen's kappa (κ).

RESULTS

The CVS-Q was developed with wide consensus among experts and was well accepted by the target group. It assesses the frequency and intensity of 16 symptoms using a single rating scale (symptom severity) that fits the Rasch rating scale model well. The questionnaire has sensitivity and specificity over 70% and achieved good test-retest repeatability both for the scores obtained [ICC = 0.802; 95% confidence interval (CI): 0.673, 0.884] and CVS classification (κ = 0.612; 95% CI: 0.384, 0.839).

CONCLUSION

The CVS-Q has acceptable psychometric properties, making it a valid and reliable tool to control the visual health of computer workers, and can potentially be used in clinical trials and outcome research.

Vision-related problems among the workers engaged in jewellery manufacturing

Background:

American Optometric Association defines Computer Vision Syndrome (CVS) as “complex of eye and vision problems related to near work which are experienced during or related to computer use.” This happens when visual demand of the tasks exceeds the visual ability of the users. Even though problems were initially attributed to computer-related activities subsequently similar problems are also reported while carrying any near point task. Jewellery manufacturing activities involves precision designs, setting the tiny metals and stones which requires high visual attention and mental concentration and are often near point task. It is therefore expected that the workers engaged in jewellery manufacturing may also experience symptoms like CVS.

Aim:

Keeping the above in mind, this study was taken up (1) To identify the prevalence of symptoms like CVS among the workers of the jewellery manufacturing and compare the same with the workers working at computer workstation and (2) To ascertain whether such symptoms have any permanent vision-related problems.

Setting and Design:

Case control study.

Materials and Methods:

The study was carried out in Zaveri Bazaar region and at an IT-enabled organization in Mumbai. The study involved the identification of symptoms of CVS using a questionnaire of Eye Strain Journal, opthalmological check-ups and measurement of Spontaneous Eye Blink rate. The data obtained from the jewellery manufacturing was compared with the data of the subjects engaged in computer work and with the data available in the literature.

Statistical Analysis:

A comparative inferential statistics was used.

Results and Conclusion:

Results showed that visual demands of the task carried out in jewellery manufacturing were much higher than that of carried out in computer-related work.

Prevalence of musculoskeletal discomfort among the workers engaged in jewelry manufacturing

Background:

The workers engaged in jewellery manufacturing exposed to various occupational risk factors that lead to development of musculoskeletal disorders. But there is scarcity of reporting the prevalence of the musculoskeletal disorders among them.

Aims:

To evaluate the prevalence of musculoskeletal discomfort among the workers engaged in jewellery manufacturing in India.

Setting and Design:

Case Control Study.

Materials and Methods:

This study was divided into two phases. First phase: prevalence rate were calculated using Modified Nordic musculoskeletal questionnaire and compared with the control group. Second phase: strength, flexibility and tightness of the muscle groups (neck, lower back and knee) were evaluated through physical examination for the subjects who reported positive prevalence.

Statistical Analysis:

A comparative inferential statistics was used.

Results:

This study was divided into two phases. First phase: prevalence rate were calculated using Modified Nordic musculoskeletal questionnaire and compared with the control group. Second phase:strength, flexibility and tightness of the muscle groups (neck, lower back and knee) were evaluated through physical examination for the subjects who reported positive prevalence.

Conclusions:

The musculoskeletal disorders among the workers engaged in jewellery manufacturing were found to be specific to the occupation.

Temporal Co-Variation between Eye Lens Accommodation and Trapezius Muscle Activity during a Dynamic Near-Far Visual Task

Near work is associated with increased activity in the neck and shoulder muscles, but the underlying mechanism is still unknown. This study was designed to determine whether a dynamic change in focus, alternating between a nearby and a more distant visual target, produces a direct parallel change in trapezius muscle activity. Fourteen healthy controls and 12 patients with a history of visual and neck/shoulder symptoms performed a Near-Far visual task under three different viewing conditions; one neutral condition with no trial lenses, one condition with negative trial lenses to create increased accommodation, and one condition with positive trial lenses to create decreased accommodation. Eye lens accommodation and trapezius muscle activity were continuously recorded. The trapezius muscle activity was significantly higher during Near than during Far focusing periods for both groups within the neutral viewing condition, and there was a significant co-variation in time between accommodation and trapezius muscle activity within the neutral and positive viewing conditions for the control group. In conclusion, these results reveal a connection between Near focusing and increased muscle activity during dynamic changes in focus between a nearby and a far target. A direct link, from the accommodation/vergence system to the trapezius muscles cannot be ruled out, but the connection may also be explained by an increased need for eye-neck (head) stabilization when focusing on a nearby target as compared to a more distant target.

The relationship among computer work, environmental design, and musculoskeletal and visual discomfort: examining the moderating role of supervisory relations and co-worker support

PURPOSE

The prevalence of work-related upper extremity musculoskeletal disorders and visual symptoms reported in the USA has increased dramatically during the past two decades. This study examined the factors of computer use, workspace design, psychosocial factors, and organizational ergonomics resources on musculoskeletal and visual discomfort and their impact on the safety and health of computer work employees.

METHODS

A large-scale, cross-sectional survey was administered to a US manufacturing company to investigate these relationships (n = 1259). Associations between these study variables were tested along with moderating effects framed within a conceptual model.

RESULTS

Significant relationships were found between computer use and psychosocial factors of co-worker support and supervisory relations with visual and musculoskeletal discomfort. Co-worker support was found to be significantly related to reports of eyestrain, headaches, and musculoskeletal discomfort. Supervisor relations partially moderated the relationship between workspace design satisfaction and visual and musculoskeletal discomfort.

CONCLUSION

This study provides guidance for developing systematic, preventive measures and recommendations in designing office ergonomics interventions with the goal of reducing musculoskeletal and visual discomfort while enhancing office and computer workers' performance and safety.

Work-related health disorders among Saudi computer users

The present study was conducted to investigate the prevalence of musculoskeletal disorders and eye and vision complaints among the computer users of King Abdulaziz University (KAU), Saudi Arabian Airlines (SAUDIA), and Saudi Telecom Company (STC). Stratified random samples of the work stations and operators at each of the studied institutions were selected and the ergonomics of the work stations were assessed and the operators' health complaints were investigated. The average ergonomic score of the studied work station at STC, KAU, and SAUDIA was 81.5%, 73.3%, and 70.3, respectively. Most of the examined operators use computers daily for ≤ 7 hours, yet they had some average incidences of general complaints (e.g., headache, body fatigue, and lack of concentration) and relatively high level of incidences of eye and vision complaints and musculoskeletal complaints. The incidences of the complaints have been found to increase with the (a) decrease in work station ergonomic score, (b) progress of age and duration of employment, (c) smoking, (d) use of computers, (e) lack of work satisfaction, and (f) history of operators' previous ailments. It has been recommended to improve the ergonomics of the work stations, set up training programs, and conduct preplacement and periodical examinations for operators.

Comparison of ocular surface disease index and tear osmolarity as markers of ocular surface dysfunction in video terminal display workers

PURPOSE

To compare the Ocular Surface Disease Index (OSDI) questionnaire and tear osmolarity, to screen ocular surface alterations in video display terminal (VDT) users.

DESIGN

Cross-sectional study.

METHODS

Sixty-four VDT workers were screened for ocular surface alterations using OSDI and tear osmolarity. Furthermore, tear film break-up time (TBUT), fluorescein corneal stain, and assessment for meibomian glands dysfunction (MGD) were carried out. The alteration of 2 or more among these parameters was considered a sign of ocular surface dysfunction. Data for the statistical analysis were obtained from the eyes with the worst tear osmolarity score. Main outcome measures were OSDI and tear osmolarity. For the statistical analysis the receiver operating characteristic (ROC) curves and Spearman correlation coefficient were used. A P < .05 was considered statistically significant.

RESULTS

The area under the ROC curve (AUC) for tear osmolarity (ranging from 0.71 to 0.86) showed, for all the classification variables considered, statistically significantly higher values than those obtained with OSDI (ranging from 0.51 to 0.58) (P < .01). Furthermore, tear osmolarity showed a direct correlation with corneal stain and ocular surface dysfunction and an inverse correlation for TBUT. No correlation was found between OSDI and the parameters considered.

CONCLUSIONS

Tear osmolarity can be considered a more reliable test than OSDI, when screening VDT users for possible ocular surface alterations.

Individual and work-related risk factors for musculoskeletal pain: a cross-sectional study among Estonian computer users

Background

Occupational use of computers has increased rapidly over recent decades, and has been linked with various musculoskeletal disorders, which are now the most commonly diagnosed occupational diseases in Estonia. The aim of this study was to assess the prevalence of musculoskeletal pain (MSP) by anatomical region during the past 12 months and to investigate its association with personal characteristics and work-related risk factors among Estonian office workers using computers.

Methods

In a cross-sectional survey, the questionnaires were sent to the 415 computer users. Data were collected by self-administered questionnaire from 202 computer users at two universities in Estonia. The questionnaire asked about MSP at different anatomical sites, and potential individual and work related risk factors. Associations with risk factors were assessed by logistic regression.

Results

Most respondents (77%) reported MSP in at least one anatomical region during the past 12 months. Most prevalent was pain in the neck (51%), followed by low back pain (42%), wrist/hand pain (35%) and shoulder pain (30%). Older age, right-handedness, not currently smoking, emotional exhaustion, belief that musculoskeletal problems are commonly caused by work, and low job security were the statistically significant risk factors for MSP in different anatomical sites.

Conclusions

A high prevalence of MSP in the neck, low back, wrist/arm and shoulder was observed among Estonian computer users. Psychosocial risk factors were broadly consistent with those reported from elsewhere. While computer users should be aware of ergonomic techniques that can make their work easier and more comfortable, presenting computer use as a serious health hazard may modify health beliefs in a way that is unhelpful.

Prevalence of asthenopia and its risk factors in Chinese college students

AIM

To determine the prevalence of asthenopia and identify any associated risk factors in the college students in Xi'an, China.

METHODS

From April to September 2012, 1 500 students from five universities in Xi'an were selected according to a multi-stage stratified cluster sampling method. Data on demographic features, lifestyle or dietary habits, health status, living environment conditions, sleep and mental status, and asthenopia symptoms were collected through a self-administered validated questionnaire. Univariate logistic regression and multivariate logistic regression analysis modified by the factor analysis were performed to evaluate risk factors for asthenopia.

RESULTS

Fifty-seven percent of the college students complained of asthenopia. Statistically significant risk factors for asthenopia in the univariate analysis included 13 variables. Multivariate analysis revealed a significant relationship between the use of computer and asthenopia (OR 1.21, 95%CI: 1.09 to 1.35). Good sleep and mental status (OR 0.86, 95%CI: 0.76 to 0.97), good living environment conditions (OR 0.67, 95%CI: 0.60 to 0.76), and high intake of green leafy vegetables (OR 0.89, 95%CI: 0.80 to 0.98) were found to be strong predictors of decreasing the occurrence of asthenopia complaints.

CONCLUSION

Asthenopia symptom appears to be common among college students; and it is strongly associated with computer use, psychosocial state, environment conditions and dietary habits, suggesting that additional studies are warranted to verify these risk factors and establish prevention guidelines, especially for college students.

A pilot randomised control trial of the effectiveness of a biofeedback mouse in reducing self-reported pain among office workers

A pilot study examined the effectiveness of a biofeedback mouse in reducing upper extremity pain and discomfort in office workers; in addition, relative mouse use (RMU), satisfaction and the feasibility of running a randomised controlled trial (RCT) in a workplace setting were evaluated. The mouse would gently vibrate if the hand was idle for more than 12 s. The feedback reminded users to rest the arm in neutral, supported postures. Analysis showed a statistically significant reduction in shoulder pain and discomfort for the intervention group at T2 (38.7% lower than controls). Statistically significant differences in RMU time between groups were seen post intervention (-7% at T1 and +15% at T2 for the intervention group). Fifty-five percent of the intervention group was willing to continue using the mouse. It appears feasible to perform an RCT for this type of intervention in a workplace setting. Further study including more participants is suggested.

PRACTITIONER SUMMARY

The study findings support the feasibility of conducting randomised control trials in office settings to evaluate ergonomics interventions. The intervention resulted in reduced pain and discomfort in the shoulder. The intervention could be a relevant tool in the reduction of upper extremity musculoskeletal disorder. Further research will better explain the study's preliminary findings.

The predictive validity of the RSI QuickScan questionnaire with respect to arm, shoulder and neck symptoms in computer workers

The aim of this study was to determine whether results from the RSI QuickScan questionnaire on risk factors for arm, shoulder and neck symptoms can predict future arm, neck and shoulder symptoms in a population of computer workers. For this prospective cohort study, with a follow-up of 24 months, 3383 workers who regularly worked with a computer were approached. Generalised estimating equations (GEE) with 6, 12, 18 and 24 months time lags were used to determine whether high exposure was related to symptoms at follow-up. The results showed that high scores on 9 out of 13 scales, including previous symptoms, were significantly related to arm, shoulder and neck symptoms at follow-up. These results provide support for the predictive validity of the RSI QuickScan questionnaire.

PRACTITIONER SUMMARY

The results showed that high scores on 9 out of 13 scales, including previous symptoms, were significantly related to arm, shoulder and neck symptoms at follow-up. The RSI QuickScan questionnaire may be recommended as a tool in the identification of computer workers who should be targeted with interventions aimed at prevention of future symptoms.

Effects of job-related stress and burnout on asthenopia among high-tech workers

Eye- and vision-related symptoms are the most frequent health problems among computer users. The findings of eye strain, tired eyes, eye irritation, burning sensation, redness, blurred vision and double vision, when appearing together, have recently been termed 'computer vision syndrome', or asthenopia. To examine the frequency and intensity of asthenopia among individuals employed in research and development departments of high-tech firms and the effects of job stress and burnout on ocular complaints, this study included 106 subjects, 42 high-tech workers (study group) and 64 bank employees (control group). All participants completed self-report questionnaires covering demographics, asthenopia, satisfaction with work environmental conditions, job-related stress and burnout. There was a significant between-group difference in the intensity of asthenopia, but not in its frequency. Burnout appeared to be a significant contributing factor to the intensity and frequency of asthenopia. This study shows that burnout is a significant factor in asthenopic complaints in high-tech workers.

PRACTITIONER SUMMARY

This manuscript analyses the effects of psychological environmental factors, such as job stress and burnout, on ocular complaints at the workplace of computer users. The findings may have an ergonomic impact on how to improve health, safety and comfort of the working environment among computer users, for better perception of the job environment, efficacy and production.

Inconsistencies in guidelines for visual health surveillance of VDT workers

OBJECTIVES

In Europe, 25% of workers use video display terminals (VDTs). Occupational health surveillance has been considered a key element in the protection of these workers. Nevertheless, it is unclear if guidelines available for this purpose, based on EU standards and available evidence, meet currently accepted quality criteria. The aim of this study was to appraise three sets of European VDT guidelines (UK, France, Spain) in which regulatory and evidence-based approaches for visual health have been formulated and recommendations for practice made.

METHODS

Three independent appraisers used an adapted AGREE instrument with seven domains to appraise the guidelines. A modified nominal group technique approach was used in two consecutive phases: first, individual evaluation of the three guidelines simultaneously, and second, a face-to-face meeting of appraisers to discuss scoring. Analysis of ratings obtained in each domain and variability among appraisers was undertaken (correlation and kappa coefficients).

RESULTS

All guidelines had low domain scores. The domain evaluated most highly was Scope and purpose, while Applicability was scored minimally. The UK guidelines had the highest overall score, and the Spanish ones had the lowest. The analysis of reliability and differences between scores in each domain showed a high level of agreement.

CONCLUSIONS

These results suggest current guidelines used in these countries need an update. The formulation of evidence-base European guidelines on VDT could help to reduce the significant variation of national guidelines, which may have an impact on practical application.

Effects of passive computer use time and non-computer work time on the performance of electronic activity monitoring

This study aimed to examine the effects of passive and non-computer work time on the estimation of computer use times by electronic activity monitoring. A total of 20 subjects with computers were monitored for 3 h. Average relative error for total computer use time estimation was about 4%, given that non-computer work time was 20% of the 3-h monitored period. No significant impact of passive computer use time was found in this study. Non-computer work time of 40% or less is suggested as criteria for the application of electronic activity monitoring to ensure reliability in the physical work loading assessment. Statement of Relevance: This research studied the criteria of non-computer work time for the appropriate use of electronic activity monitoring to ensure reliability in the assessment of physical work loading. It is suggested that it should be set to 40% or less of the 3-h monitoring period.

Differences in prevalence of self-reported musculoskeletal symptoms among computer and non-computer users in a Nigerian population: a cross-sectional study

BACKGROUND

Literature abounds on the prevalent nature of Self Reported Musculoskeletal Symptoms (SRMS) among computer users, but studies that actually compared this with non computer users are meagre thereby reducing the strength of the evidence. This study compared the prevalence of SRMS between computer and non computer users and assessed the risk factors associated with SRMS.

METHODS

A total of 472 participants comprising equal numbers of age and sex matched computer and non computer users were assessed for the presence of SRMS. Information concerning musculoskeletal symptoms and discomforts from the neck, shoulders, upper back, elbows, wrists/hands, low back, hips/thighs, knees and ankles/feet were obtained using the Standardized Nordic questionnaire.

RESULTS

The prevalence of SRMS was significantly higher in the computer users than the non computer users both over the past 7 days (chi2 = 39.11, p = 0.001) and during the past 12 month durations (chi2 = 53.56, p = 0.001). The odds of reporting musculoskeletal symptoms was least for participants above the age of 40 years (OR = 0.42, 95% CI = 0.31-0.64 over the past 7 days and OR = 0.61; 95% CI = 0.47-0.77 during the past 12 months) and also reduced in female participants. Increasing daily hours and accumulated years of computer use and tasks of data processing and designs/graphics significantly (p < 0.05) increased the risk of reporting musculoskeletal symptoms. Over the past 7 day duration, the neck (33.9%) and low back (11.4%) had highest prevalence of SRMS for the computer and non computer users respectively.

CONCLUSION

The prevalence of SRMS was significantly higher in the computer users than the non computer users and younger age, being male, working longer hours daily, increasing years of computer use, data entry tasks and computer designs/graphics were the significant risk factors for reporting musculoskeletal symptoms among the computer users. Computer use may explain the increase in prevalence of SRMS among the computer users.

The effect of idle time thresholds on computer use time estimations by electronic monitoring

This study examined the effect of idle time setting on the estimation of computer use times by electronic activity monitoring and validated its use by comparing it with video record observations. Twenty-four study subjects were recruited and their work with computers was monitored for 1 h. With the estimates by video record observation as references, the best idle time settings for electronic activity monitoring with the least relative errors were 25, 2.5 and 2.5 s, respectively, for total computer, keyboard and mouse use time estimations. These estimates were highly correlated with the corresponding references (r = 0.918-0.964, p < 0.0001), accompanied by limited mean estimate differences ranging from -3.0 +/- 2.8% to 1.3 +/- 1.6%. The estimates by self-report were moderately correlated with the corresponding references (r = 0.387-0.678), with greater mean estimate differences. This study concluded that, for electronic activity monitoring methods, the most appropriate thresholds for idle time setting are 25 s, 2.5 s and 2.5 s for total computer, keyboard and mouse use time estimates, respectively. This method may help evaluate physical work-loading with computer works through a large-scale epidemiological study.

The impact of computer display height and desk design on 3D posture during information technology work by young adults

Computer display height and desk design to allow forearm support are two critical design features of workstations for information technology tasks. However there is currently no 3D description of head and neck posture with different computer display heights and no direct comparison to paper based information technology tasks. There is also inconsistent evidence on the effect of forearm support on posture and no evidence on whether these features interact. This study compared the 3D head, neck and upper limb postures of 18 male and 18 female young adults whilst working with different display and desk design conditions. There was no substantial interaction between display height and desk design. Lower display heights increased head and neck flexion with more spinal asymmetry when working with paper. The curved desk, designed to provide forearm support, increased scapula elevation/protraction and shoulder flexion/abduction.

The dichotomy of relative humidity on indoor air quality

Dry and irritated mucous membranes of the eyes and airways are common symptoms reported in office-like environments. Earlier studies suggested that indoor pollutants were responsible. We have re-evaluated, by review of the literature, how low relative humidity (RH) may influence the immediately perceived indoor air quality (IAQ), including odour, and cause irritation symptoms (i.e. longer-term perceived IAQ). "Relative humidity" were searched in major databases, and combined with: air quality, cabin air, dry eyes, formaldehyde, inflammation, mucous membranes, offices, ozone, pungency, sensory irritation, particles, precorneal tear film, sick building syndrome, stuffy air, and VOCs. The impact of RH on the immediately and longer-term perceived IAQ by VOCs, ozone, and particles is complex, because both the thermodynamic condition and the emission characteristics of building materials are influenced. Epidemiological, clinical, and human exposure studies indicate that low RH plays a role in the increase of reporting eye irritation symptoms and alteration of the precorneal tear film. These effects may be exacerbated during visual display unit work. The recommendation that IAQ should be "dry and cool" may be useful for evaluation of the immediately perceived IAQ in material emission testing, but should be considered cautiously about the development of irritation symptoms in eyes and upper airways during a workday. Studies indicate that RH about 40% is better for the eyes and upper airways than levels below 30%. The optimal RH may differ for the eyes and the airways regarding desiccation of the mucous membranes.

Are there differences between ‘visual symptoms’ and specific ocular symptoms associated with video display terminal (VDT) use?

To assess the reliability of self-reported symptoms of asthenopia associated with VDT use (as characterized by general visual symptoms, headache and specific ocular symptoms) for both continuing soft contact lens (SCL) wearers and former SCL wearers who had undergone successful laser-in-situ-keratomileusis (LASIK) surgery.

METHODS

Forty generally healthy adults, aged between 24 and 44 years, were asked to complete a 13 page questionnaire that included requests for information on general visual symptoms, headache and specific ocular symptoms such as dry eye associated with VDT use. The adults were either long term successful soft contact lens wearers (n=20) or a similar group who had then undergone successful LASIK refractive surgery for myopia 2 years prior to the questionnaire being provided.

RESULTS

Most subjects (70%) reported experiencing some visual symptoms sometimes, 62.5% reported headaches sometimes, and 82.5 % reported specific ocular symptoms sometimes. There were no obvious differences between the two groups either in the reported frequency or severity (by visual analogue scale, VAS) of visual symptoms, headache or specific ocular symptoms. However, while the reporting of headache showed no obvious association with the number of specific ocular symptoms reported, the latter showed a clear correlation with the reporting of the severity of visual symptoms (p<0.001).

DISCUSSION

The results indicate that when an individual reports visual symptoms, they may actually be providing recall of specific ocular symptoms. Therefore, contrary to an often common practice, visual symptoms should be assessed separately to specific ocular symptoms such that the appropriate management can be selected. The results also indicate that previous contact lens wearers who have undergone successful LASIK are still likely to experience some visual and specific ocular symptoms when undertaking computer based work on a regular basis.