Risk factors for neck and upper extremity disorders among computers users and the effect of interventions: an overview of systematic reviews

Validity of an expert-based job exposure matrix of hand-wrist physical exposures and their prospective associations with carpal tunnel syndrome

BACKGROUND

Epidemiological studies of occupational risk factors for rare disorders require large study populations with adequate exposure estimates. Job exposure matrices (JEMs) linked to national information on standardized job titles may enable such large studies. We aimed to establish and validate a JEM for occupational hand-wrist exposures that could be linked to Danish national register data on job titles and hand-wrist disorders.

METHODS

We developed a JEM for hand-wrist repetition, force, vibration, and computer work in 96 job groups covering 91% of the 2227 occupational titles in the Danish version of the International Standard Classification of Occupation-88, and examined inter-rater reliability of five expert ratings. Poisson regression models were used to estimate incidence rate ratios for the association of carpal tunnel syndrome (CTS) with the level of repetitive movements, force, vibration, and hours of computer work described by the JEM, adjusted for relevant confounders.

RESULTS

The JEM based on expert ratings had fair to good interrater reliability. The incidence of CTS increased with increasing levels of force, hand-wrist repetition, and vibration, Exposure-response patterns for repetition and vibration became less consistent after adjustment for force. The interaction between repetition and force was complex and did not support an overall positive interaction. Computer work was negatively associated with incident CTS.

CONCLUSION

The JEM was able to identify known risk factors for CTS consistent with current evidence, and provided further associations on exposure-response patterns, mutual exposure adjustment, and interaction effects between repetition and force. The reliability of expert assessments of hand-wrist physical exposures was fair to good.

Can biofeedback training in combination with ergonomic information reduce pain among young adult computer users with neck and upper extremity symptoms? - A randomized controlled intervention study

The aim of this randomized controlled study was to explore if an intervention with biofeedback training in combination with ergonomic discussions, could improve working technique and work postures, and reduce pain intensity and perceived exertion in young adult computer users with ongoing neck and upper extremity symptoms. 39 participants were divided into an intervention group and a control group. The intervention consisted of 4 sessions during a three-month period. Working technique, working postures, rated perceived exertion, pain intensity, and duration of computer use were measured at baseline and follow ups after 6 and 12 months. The intervention did not significantly improve working technique and working postures, nor reduce pain intensity and perceived exertion in the intervention group compared to the control group. However, there was a statistically significant reduction in reported pain intensity in the neck/shoulder for the whole group. Also, there was a trend that time spent with computer work without breaks was more reduced in the intervention group than in the control group.

Investigating the Effect of Keyboard Distance on the Posture and 3D Moments of Wrist and Elbow Joints among Males Using OpenSim

Musculoskeletal disorders (MSDs) of the upper extremities and computer use are common in modern societies, and both show a growing trend. This study was conducted to determine the posture and 3D moments of wrist and elbow joints at different keyboard distances on a desk. Twelve healthy right-handed male volunteers attended the motion analysis laboratory. A keyboard was placed at three different distances from the participants’ bodies while performing a standard computer task. The workstation was adjusted according to ANSI/HFES-100-2007 standard for each participant to maintain a comfortable ergonomic posture for controlling confounding variables. Qualisys motion capture system, OpenSim (Ver. 4.1), and visual analog scale were used to collect and analyze the data. The highest levels of wrist flexion and radial deviation as well as elbow flexion and pronation were observed when the keyboard was at the edge of the desk. When the keyboard was 8 cm away from the edge of the desk, the right wrist flexion and radial deviation decreased 83% and 89%, respectively. In the left wrist, flexion and radial deviation decreased 94%. With increasing the distance of the keyboard from the edge of the desk, the right elbow flexion, pronation, and left elbow flexion decreased, 95%, 76%, and 85%, respectively. No significant difference was found for the left elbow pronation, wrist, and elbow joint moments, in the studied keyboard distances. However, a cut-off point has to be specified because large keyboard distances cause high extension and flexion of the limbs. The keyboard position relative to the body is an important parameter in computer work and has a significant impact on the posture of the upper extremities. A keyboard should be located at a distance that allows the upper extremities to remain in a neutral position so that the risk of MSDs is reduced.

Musculoskeletal health climate is associated with musculoskeletal pain and sickness absence among workers: a cross-sectional study

OBJECTIVES

This study aimed to investigate whether a musculoskeletal health climate, expressing the shared perceptions among workers concerning musculoskeletal health, is associated with number of musculoskeletal pain sites and sickness absence.

DESIGN

Cross-sectional study.

SETTING

Six slaughterhouses from 2 companies in Denmark and 6 home-nursing units and 12 nursing homes from 1 municipality in Jutland, Denmark.

PARTICIPANTS

A total of 1092 slaughter house workers and 410 care workers completed an online questionnaire from February to October 2019.

OUTCOME MEASURES

The exposure variable was musculoskeletal health climate assessed by two domains; (1) perceived management priority of musculoskeletal health measured by a modified subscale from the Nordic Safety Climate Questionnaire and (2) work group pain acceptance which was a modified version of the activity engagement subscale of the chronic pain acceptance scale. Outcomes variables were number of musculoskeletal pain sites (0-6) and days with sickness absence.

RESULTS

The associations between the two subscales, number of musculoskeletal pain sites and sickness absence were calculated using mixed linear and generalised estimating equation regression models. Higher perceived management priority scores were associated with a lower number of musculoskeletal pain sites across both job groups: β=-.57 (95% CI -0.91 to -0.23) and sickness absence (>5 days) due to musculoskeletal pain prevalence ratio (PR) 0.79 (95% CI 0.57 to 1.08). In contrast higher work group pain acceptance scores were associated with higher number of musculoskeletal pain sites: β=0.38 (0.11 to 0.66), whereas associations with sickness absences seemed to be modified by job groups; PR 1.59 care workers and PR 0.86 slaughterhouse workers.

CONCLUSION

The observed relationship between musculoskeletal health climate, musculoskeletal pain sites and sickness absence indicate that cultural factors should receive increased attention in work place preventive interventions.

Influence of gender and age on musculoskeletal symptoms in white and blue-collar workers - cross-sectional study

OBJECTIVE

Identify the prevalence of musculoskeletal symptoms among blue- and white-collar workers stratified by gender and age.

METHODS

The sample was composed of 390 blue-collar and 510 white-collar workers. Musculoskeletal symptoms were evaluated using the Nordic Musculoskeletal Questionnaire. Independent t-test or Mann-Whitney test were used for the inter-group comparisons. The Chi-square (χ²) association test was applied for categorical variables. Logistic regression analysis was used to determine the influence of gender and age on musculoskeletal symptoms.

RESULTS

The prevalence of shoulder, lower back, and ankle/foot symptoms was higher among blue-collar workers compared to white-collar workers. In the analysis stratified by gender, female blue-collar workers had a higher frequency of shoulder symptoms and male blue-collar workers had a higher frequency of lower back symptoms. In the analysis stratified by age, younger blue collar-workers had a higher frequency of shoulder, lower back, and ankle/foot symptoms compared to young white-collar workers and older white-collar workers had a higher frequency of neck symptoms compared to older blue-collar workers.

CONCLUSIONS

Gender and age exerted an influence on self-reported symptoms in blue- and white-collar workers.

COVİD-19 PANDEMİSİ SÜRESİNCE UZAKTAN EĞİTİM GÖREN ÜNİVERSİTE ÖĞRENCİLERİNİN YAŞADIĞI BOYUN VE ÜST EKSTREMİTE AĞRILARI VE DİZABİLİTE

Objective: Musculoskeletal system problems emerged in students who had to attend classes with a computer or smartphone during the weekly course hours, due to the fact that the universities providing face-to-face education switched to the online method of distance education due to the Covid-19 pandemic. Purpose of the study; To determine the severity of the pain experienced by the students, to reveal its relationship with disability, and to find the factors that induce pain and disability in daily life. Method: 100 students between the ages of 18-25, who attended distance education for at least 2 academic semesters and met the study criteria were included in the study. After the Sociodemographic Data Questionnaire was applied to the students included in the study, the Arm, Shoulder and Hand Problems Quick Questionnaire (Q-DASH), Neck Disability Index and NRS tests were applied. Results: As a result of the Quick Questionnaire for Arm, Shoulder and Hand Problems (Q-DASH), 43% of the students included in the study had moderate disability, and according to the Neck Disability Index, 37% of the study group had complete disability. According to multivariate regression analysis, gender (p

Online supervised versus workplace corrective exercises for upper crossed syndrome: a protocol for a randomized controlled trial

Background and objective

Musculoskeletal disorders (MSDs) including upper crossed syndrome (UCS) are considered as the leading cause of work-related issues worldwide among office workers. Therefore, the present study aims to evaluate the effect of workplace-based versus online-supervised home-based corrective exercises among office workers with UCS.

Methods and design

To this end, 45 subjects within the age range of 30–45 years are randomly assigned to three groups in the present parallel-group, randomized control trial using a pretest-posttest design. These groups include the subjects who receive online-supervised exercise and workplace exercise containing three sessions of intervention for 8 weeks and the control group receives no intervention while performing routine activities. The primary outcome variables are neck-shoulder pain (NSP) and consequent sick leave due to NSP, followed by alignment, workability, and the surface electromyography of upper, middle, and lower trapezius (UT, MT, and LT), sternocleidomastoid (SCM), and serratus anterior (SA) as the secondary variables.

Discussion

The present study seeks to assess the effect of workplace versus online-supervised corrective exercise interventions among 45 office workers suffering from UCS. It is expected to improve and reduce the related symptoms including postural malalignment and imbalance muscles after 8 weeks of corrective exercises. If effective, the findings may lead to adherence and work performance among the office workers, and individuals subjected to UCS can use the benefits of an online-supervised intervention. In addition, the findings may be useful in different workplaces as the evidence for employers to benefit from the reduction in the related costs and side effects of work-related neck/shoulder disorders including work disability, productivity loss, time expense, social insurance, work absenteeism, and treatment costs. Finally, clinicians and corrective exercise therapists can consider it as a clinical based-evidence intervention for their further actions.

Trial registration

Iranian Registry of Clinical Trials IRCT20200729048249N1. Registered on 5 October 2020 (https://en.irct.ir/user/trial/49992/view)

The impact of e-learning during COVID-19 pandemic on students' body aches in Palestine

Musculoskeletal pain is a major concern in our life due to its negative effects on our ability to perform daily functions. During COVID-19 pandemic, several countries switched their teaching programs into e-learning, where students spend long hour using electronic devices. The use of these devices was associated with several musculoskeletal complains among the students. The aim of this study is to evaluate the different body aches associated with e-learning on university students. The subjects of this study were students from An-Najah University in Palestine. 385 questionnaires were filled using Google forms questionnaire and all the subjects were using e-learning due to COVID-19 pandemic. Our study showed that a large percentage of participants used electronic devices for e-learning during the pandemic. The Duration of these devices use was correlated with duration and degree of pain, and associated with the difficulty in ability to perform several daily activities. Furthermore, most of the students used the sitting position with supine bent forward during the device usage. Thus, the university students that participated in this study had an increase in body aches during the e-learning process, and the aches duration and severity increases if the duration of electronic devices usage increase.

Developing a practice and evidence-based guideline for occupational health and safety professionals to prevent and handle musculoskeletal pain in workplaces

Practice guidelines can facilitate the translation of evidence-based knowledge into better occupational health and safety (OHS) prevention. This paper describes the development process, findings and content of a practice and evidence-based guideline for musculoskeletal pain (MSP) to OHS professionals in Denmark. We used a participatory process with involvement of more than 100 OHS professionals in the development of the guideline. The guideline contains three sections: 1) Rapid review of risk factors for MSP (Push/pull, Screen work, Lifting, Awkward postures and Psychosocial factors related to MSP) and single- and multi-stranded interventions targeting MSP. 2) Process recommendations for use of the guideline by a three-phase participatory process 3) Practical recommendations that contain advice and methods for the three-phase participatory process. This paper can promote future guideline development, as it provides specific insight into how OHS professionals can be included in the development of practice and evidence-based guideline through a participatory process.

Do psychosocial factors mediate the appearance of musculoskeletal symptoms? Evidence of an empirical study about the role of mental workload in computer workers

The emergence of musculoskeletal symptoms (MSSs) in computer workers is a relevant occupational health problem. This study tests a multilevel model of analysis of risk factors in the appearance of musculoskeletal pain and discomfort in computer workers that integrates indicators from different areas: temporal usage patterns, ergonomic factors, psychosocial factors, and individual variables, specifically testing the possible mediating role of the mental workload. A cross-sectional study was performed through online registration with a non-probabilistic sample of 1198 workers from Spanish organizations. The results show that mental workload has a higher association than the rest of the factors with the onset of pain and discomfort in various body areas: neck in men, neck, shoulders and upper back in women. They also support the mediation role of mental workload in the relationship between usage patterns and the appearance of musculoskeletal symptoms. The use of multilevel theoretical models that adequately consider the complexity of the relationships between the different risk factors is necessary for a better understanding and intervention on MSSs in computer workers.

Carpal Tunnel Syndrome: A National Survey to Monitor Knowledge and Operating Methods

The aim of this article was to investigate the knowledge, management, and clinical practice of Italian physiotherapists concerning patients with carpal tunnel syndrome (CTS). A national cross-sectional survey consisted of 24 questions was administered from December 2019 until February 2020. A Chi-squared independence test was run to study any difference between subgroups of the sample and responses to the questionnaire. Five hundred and eight respondents completed the survey. Most respondents (n = 225/508; 44.3%) are under 29 years old, female (n = 256/508; 50.4%) and have been working as physiotherapists for less than 5 years (n = 213/508; 41.9%). Most of respondents correctly knows about the cause (n = 455/508, 89.6%), main signs and symptoms of CTS (n = 415/508, 81.70%) and administer education, manual therapy, myofascial techniques and therapeutic exercises (n = 457/508, 89.88%). Three hundred and sixty-four (71.68%) respondents were aware of the influence of psychosocial factors on the patient’s outcomes. The survey showed greater adherence to evidences by physiotherapists holding a master’s degree. The results are mostly comparable with other surveys structured all over the world on the same topic. Italian physiotherapists management of the CTS was not always in line with current evidence. Interventions such as education, manual therapy, therapeutic exercise, nerve and tendon glide techniques are widely used, while the orthotic is only offered by half of the sample.

Text Neck Syndrome in Children and Adolescents

Neck pain is a prevalent health problem, largely reported in adult patients. However, very recent data show that new technologies are inducing a shift in the prevalence of this relevant issue from adulthood to all of the pediatric ages. In fact, the precocious and inappropriate use of personal computers and especially cell phones might be related to the development of a complex cluster of clinical symptoms commonly defined as "text neck syndrome". The purpose of this article is to analyze the new phenomenon of the "text neck syndrome", the underlying causes and risk factors of musculoskeletal pain, that can be modified by changes in routine life, in different cultures and habits, and on the "text neck syndrome" as increased stresses on the cervical spine, that can lead to cervical degeneration along with other developmental, medical, psychological, and social complications. Findings support the contention that an appropriate approach for an early diagnosis and treatment is crucial to properly evaluate this emerging issue worldwide in children and adolescents who spend a lot of time watching smartphones and computers; additional research with more rigorous study designs and objective measures of musculoskeletal pain are needed to confirm significant relationships. Existing evidence is limited by non-objective measures and the subjective nature of musculoskeletal pain.

Methods for depicting overlap in overviews of systematic reviews: An introduction to static tabular and graphical displays

BACKGROUND AND OBJECTIVE

To introduce potential static tabular and graphical techniques for visually presenting overlap between systematic reviews (SRs) included in overviews of systematic reviews (OoSRs).

METHODS

The graphical approaches described include Venn and Euler diagrams, as well as matrix-based, node-link, and aggregation-based techniques. We used fundamental concepts of mathematics from set and network theory to develop our novel graphical approaches. The graphical displays were created using R.

RESULTS

Overview authors have the flexibility to choose from a variety of visualizations, depending on the characteristics of their study. If the OoSRs include few SRs, a Venn or an Euler diagram can be used. In case of OoSRs with more SRs, Upset plots, heatmaps, and node-link graphs are more appropriate for visualizing overlapping SRs. Stacked bar plots constitute an aggregation-based technique of illustrating overlap. Strengths and limitations of each graphical approach are presented.

CONCLUSION

The degree of overlap should be explored for the entire study and for specific outcomes of interest. The proposed graphical techniques may assist methodologists and authors in identifying overlap, which in turn may improve validity and transparency in OoSRs. More research is needed to understand which technique would be most useful and easiest to understand.

Posture during the use of electronic devices in people with chronic neck pain: A 3D motion analysis project

BACKGROUND

Non-neutral postures during computerised device use coupled with increased usage may increase the risk of neck pain. Greater knowledge of postures that individuals with neck pain adopt during computerised device use is warranted.

OBJECTIVE

To evaluate neck and upper limb posture while using a tablet, laptop and desktop computer (sitting and standing) in individuals with chronic neck pain.

METHODS

Differences in three-dimensional kinematic variables were assessed during four conditions: tablet, laptop, desktop computer (sitting and standing) in 22 individuals with chronic neck pain >3 months. Differences between kinematic variables were determined using one-way repeated measures ANOVA with Bonferroni post-hoc tests.

RESULTS

Compared to the desktop (sitting), tablet and laptop use resulted in increased neck flexion (mean difference tablet - 14.42°, 95% CI - 19.88, -8.96, P < 0.001; laptop -7.19°, -12.08, -2.31, P = .020); upper trunk flexion (tablet -14.89°, -20.22, -9.56, P < 0.001; laptop -5.56°, -10.02, -1.09, P = .009) and tablet bilateral shoulder elevation (left 11.01 mm, 2.01, 20.04, P < .016; right 13.08 mm, 3.09, 23.11, P < .006).

CONCLUSIONS

Tablet and laptop use resulted in greater neck flexion, bilateral shoulder elevation and upper trunk flexion compared to a standard desktop computer, suggesting individuals with chronic neck pain should be mindful of their posture when using these smaller devices. Future research should explore how differences in posture may influence neck pain.

Acute and chronic musculoskeletal pain situations among the working population and their pain education needs: an exploratory study

BACKGROUND

Pain affects a person's physical and psychological well-being, work performance and productivity. Working population bear their pain and continue to work which may contribute to the worsening of their pain condition. However, their pain situation was not well-examined.

OBJECTIVE

The aim of the study was to explore the prevalence of acute and chronic pain in the working population in Hong Kong, understand their pain management strategies and determine their preferences with regard to the use of electronic pain management materials.

METHODS

This was an exploratory online survey. The participants' pain history, their preferences in methods of pain management, the source of the pain management education that they had received, sources and preferences in relation to the use of the Internet for pain education, and the participants' demographic characteristics were collected.

RESULTS

A total of 210 participants joined the study, 67% of whom were experiencing pain. Of the group in pain, 71.6% were in chronic pain that has persisted for 3 months or more. Pain intensities ranged from 2.82 to 3.82 on a 10-point numeric scale. Of the participants, 85.7% reported not receiving adequate pain management education, and 91.4% of those agreed pain services were inadequate. Websites and health care professionals were the sources from which they obtained their pain management education.

CONCLUSIONS

The high prevalence of pain in the working population requires special attention. Health care professionals should be proactive and an online pain management programme can be a solution to address the critical problem of pain in the working population.

Database combinations to retrieve systematic reviews in overviews of reviews: a methodological study

Background

When conducting an Overviews of Reviews on health-related topics, it is unclear which combination of bibliographic databases authors should use for searching for SRs. Our goal was to determine which databases included the most systematic reviews and identify an optimal database combination for searching systematic reviews.

Methods

A set of 86 Overviews of Reviews with 1219 included systematic reviews was extracted from a previous study. Inclusion of the systematic reviews was assessed in MEDLINE, CINAHL, Embase, Epistemonikos, PsycINFO, and TRIP. The mean inclusion rate (% of included systematic reviews) and corresponding 95% confidence interval were calculated for each database individually, as well as for combinations of MEDLINE with each other database and reference checking.

Results

Inclusion of systematic reviews was higher in MEDLINE than in any other single database (mean inclusion rate 89.7%; 95% confidence interval [89.0–90.3%]). Combined with reference checking, this value increased to 93.7% [93.2–94.2%]. The best combination of two databases plus reference checking consisted of MEDLINE and Epistemonikos (99.2% [99.0–99.3%]). Stratification by Health Technology Assessment reports (97.7% [96.5–98.9%]) vs. Cochrane Overviews (100.0%) vs. non-Cochrane Overviews (99.3% [99.1–99.4%]) showed that inclusion was only slightly lower for Health Technology Assessment reports. However, MEDLINE, Epistemonikos, and reference checking remained the best combination. Among the 10/1219 systematic reviews not identified by this combination, five were published as websites rather than journals, two were included in CINAHL and Embase, and one was included in the database ERIC.

Conclusions

MEDLINE and Epistemonikos, complemented by reference checking of included studies, is the best database combination to identify systematic reviews on health-related topics.

Effectiveness of workplace interventions in rehabilitating musculoskeletal disorders and preventing its consequences among workers with physical and sedentary employment: systematic review protocol

BACKGROUND

Musculoskeletal disorders (MSDs) are the leading cause of work disability and sickness absence worldwide. The prevalence of MSDs increases with age, consequently challenging sustainable employability among the growing ageing workforce. Knowledge of feasible and efficient workplace-based interventions to rehabilitate MSD or prevent its consequences is therefore warranted. This systematic review will evaluate the effectiveness of workplace-based interventions on MSDs and its consequences among adult workers with physical and sedentary work tasks, respectively.

METHODS

We will search the following bibliographic databases: PubMed (including the database 'MEDLINE') and Web of Science Core Collection (including the databases 'Science Citation Index Expanded', 'Social Sciences Citation Index' and 'Arts & Humanities Citation Index'). Manual searches will also be performed. We will include randomised controlled trials (RCTs) and non-RCTs reported in English in which (1) participants are adult workers with MSD, (2) interventions are aiming at rehabilitating pain symptoms of MSD or preventing the consequences of MSD and (3) interventions are initiated and/or carried out at the workplace. The review will adhere to the 'Preferred Reporting Items for Systematic reviews and Meta-Analyses' (PRISMA) guidelines for reporting systematic reviews and the Institute for Work and Health (IWH) guidelines for workplace-based interventions. For the primary evaluation of the review, the quality assessment and evidence synthesis will conform to the IWH guidelines. Secondary evaluation will include a meta-analysis (unless the included studies do not allow this due to heterogeneity) and employ the risk of bias domains recommended by Cochrane along with the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach on the studies with pain intensity as an outcome.

DISCUSSION

This systematic review will provide knowledge on effective workplace-based interventions among physical and sedentary workers with MSD. RCTs are considered the most powerful experimental design in clinical trials, but solely including these may be too restrictive to understand effective workplace-based interventions where randomised and carefully controlled trials (RCTs) are not always possible. In order to maximize practical relevance, the selection process will, therefore, include both RCTs and non-RCTs and the quality assessment and evidence synthesis will conform to IWH guidelines focusing on developing practical guidelines for stakeholders. The result of this work will form the basis for industry-specific evidence-based recommendations on effective workplace-based interventions for rehabilitation of MSDs and its consequences that will later be operationalised into concrete and user-friendly practical tools for workplaces.

SYSTEMATIC REVIEW REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO) number CRD42018116752 .

Hand Pain and Sensory Deficits: Carpal Tunnel Syndrome

The Academy of Orthopaedic Physical Therapy and the Academy of Hand and Upper Extremity Physical Therapy have an ongoing effort to create evidence-based clinical practice guidelines (CPGs) for orthopaedic and sports physical therapy management and prevention of musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability and Health (ICF). This particular guideline focuses on hand pain and sensory deficits in carpal tunnel syndrome. J Orthop Sports Phys Ther 2019;49(5):CPG1-CPG85. doi:10.2519/jospt.2019.0301.

Associations of screen work with neck and upper extremity symptoms: a systematic review with meta-analysis

Objectives

It has often been suggested that screen work (ie, work on desktop, laptop, notebook or tablet computers) is a risk factor for neck and upper extremity symptoms. However, an up-to-date overview and quantification of evidence are lacking. We aimed to systematically review the association of exposure to screen work with neck and upper extremity symptoms from prospective studies.

Methods

An electronic database search (PubMed, Embase, Cinahl and Scopus) for prospective studies on the association of exposure to screen work and musculoskeletal symptoms was conducted. Studies were synthesised regarding extracted data and risk of bias, and meta-analyses were conducted.

Results

After screening 3423 unique references, 19 articles from 12 studies (with 18 538 participants) were included for the current review, with the most recent exposure assessment reported in 2005. Studies described duration and input frequency of screen work (ie, computer, keyboard and mouse use, assessed using self-reports or software recordings) and musculoskeletal symptoms (ie, self-reported neck/shoulder and distal upper extremity symptoms and diagnosed carpal tunnel syndrome [CTS]). Although there was overall an increased occurrence of musculoskeletal symptoms with larger exposure to screen work (relative risk: 1.11 [1.03 1.19]), findings were rather inconsistent with weaker (and statistically non-significant) risks when screen work was assessed by software recording (1.05 [0.91 1.21]) compared to with self-report (1.14 [1.03 1.19]).

Conclusions

We found an increased risk of musculoskeletal symptoms with screen work. However, the evidence is heterogeneous, and it is striking that it lacks information from contemporary screen work using laptop, notebook or tablet computers.

Rapid office strain assessment (ROSA): Cross cultural validity, reliability and structural validity of the Brazilian-Portuguese version

Forty-three occupational health professionals (observers) and 90 workers were enrolled in this study to perform the cross-cultural adaptation of the Rapid Office Strain Assessment into Brazilian Portuguese (ROSA-Br) and evaluate its psychometric properties. After cross-cultural adaptation, the measurement properties were checked in three stages: study 1: pre-testing (27 observers rated 15 office worker videos), study 2: intra- and inter-observer reliability (26 observers rated 15 office worker videos), and study 3: validity and accuracy of ROSA-Br final scores (90 office workers). For the ROSA scores, acceptable intraclass correlation coefficients were found for 75% and 86% of the intra-observer reliability comparisons for non-trained and trained observers, respectively, and for 100% of the inter-observer reliability comparisons (0.43-0.86). For construct validity, moderate correlations were observed for 70% of the comparisons between ROSA final scores and other ergonomic instruments. Moderate accuracy was observed for a ROSA-Br final score of 6 (AUC [area under the curve] = 0.72, 0.89). Taken together, these results support the use of the ROSA-Br for ergonomic field assessments and research.

Differences in typing forces, muscle activity, wrist posture, typing performance, and self-reported comfort among conventional and ultra-low travel keyboards

This study investigated the relative impact of ultra-low travel keyboards on typing force, muscle activity, wrist posture, typing performance, and self-reported comfort/preference as compared to a conventional keyboard. In a repeated-measures laboratory-based study, 20 subjects were invited to type for 10 min on each of five keyboards with different travel distances of 0.5, 0.7, 1.2, 1.6 (ultra-low travel keyboards), and 2.0 mm (a conventional keyboard). During the typing sessions, we measured typing force; muscle activity in extrinsic finger muscles (flexor digitorum superficialis and extensor digitorum communis), shoulder (trapezius) and neck (splenius capitis); wrist posture; typing performance; and self-reported comfort/preference. While using the ultra-low travel keyboards, subjects typed with less force and wrist extension, and had more ulnar deviation (p's < 0.0001) compared with conventional keyboard. However, these differences in typing forces were less than 0.5 N and less than 4° for both wrist extension and ulnar deviation. The general trend of data did not show any consistent or substantial differences in muscle activity (less than 2 %MVC) and typing performance (<5 WPM in speed; < 3% in accuracy), despite the observed statistical difference in the finger flexors and extensors muscle activity (p's < 0.19) and typing performance (p < 0.0001). However, the subjects preferred using conventional keyboards in most of the investigated self-reported comfort and preference criteria (p's < 0.4). In conclusion, these small differences indicate that using ultra-low travel keyboards may not have substantial differences in biomechanical exposures and typing performance compared to conventional keyboard; however, the subjective responses indicated that the ultra-low keyboards with the shortest key travel tended to be the least preferred.

Evaluating Short-Term Musculoskeletal Pain Changes in Desk-Based Workers Receiving a Workplace Sitting-Reduction Intervention

This paper explores changes in musculoskeletal pain among desk-based workers over three months of a workplace-delivered, sitting-reduction intervention. Participants (n = 153, 46% female; mean ± SD aged 38.9 ± 8.0 years) were cluster-randomized (n = 18 work teams) to receive an organizational change intervention, with or without an activity tracker. A modified Nordic Musculoskeletal Questionnaire assessed pain intensity (0–9; none–worst possible) in the neck, upper and lower back, upper and lower extremities, and in total. The activPAL3 (7 days, 24 h/day protocol) measured sitting and prolonged sitting in ≥30 min bouts at work. Mixed models adjusting for cluster and intervention arm examined changes in pain (n = 104), and their associations with reductions in sitting and prolonged sitting (h/10 h at work) (n = 90). Changes in pain were nonsignificant (p ≥ 0.05) and small for total pain (−0.06 [95% CI: −0.27, 0.16]) and for each body area (−0.26 [−0.66, 0.15] for upper back to 0.09 [−0.39, 0.56] for lower back). Sitting reduction was associated with reduced lower back pain (−0.84 [−1.44, −0.25] per hour, p = 0.005); other effects were small and non-significant. No substantial average changes in pain were seen; some improvement in lower back pain might be expected with larger sitting reductions. Larger samples and diverse interventions are required for more definitive evidence.

Associations of office workers' objectively assessed occupational sitting, standing and stepping time with musculoskeletal symptoms

We examined the association of musculoskeletal symptoms (MSS) with workplace sitting, standing and stepping time, as well as sitting and standing time accumulation (i.e. usual bout duration of these activities), measured objectively with the activPAL3 monitor. Using baseline data from the Stand Up Victoria trial (216 office workers, 14 workplaces), cross-sectional associations of occupational activities with self-reported MSS (low-back, upper and lower extremity symptoms in the last three months) were examined using probit regression, correcting for clustering and adjusting for confounders. Sitting bout duration was significantly (p < 0.05) associated, non-linearly, with MSS, such that those in the middle tertile displayed the highest prevalence of upper extremity symptoms. Other associations were non-significant but sometimes involved large differences in symptom prevalence (e.g. 38%) by activity. Though causation is unclear, these non-linear associations suggest that sitting and its alternatives (i.e. standing and stepping) interact with MSS and this should be considered when designing safe work systems. Practitioner summary: We studied associations of objectively assessed occupational activities with musculoskeletal symptoms in office workers. Workers who accumulated longer sitting bouts reported fewer upper extremity symptoms. Total activity duration was not significantly associated with musculoskeletal symptoms. We underline the importance of considering total volumes and patterns of activity time in musculoskeletal research.

A Brief Self-Directed Intervention to Reduce Office Employees' Sedentary Behavior in a Flexible Workplace

OBJECTIVE

The aim of the study was to assess changes in employees' sedentary behavior after a brief self-directed intervention in a flexible workplace.

METHODS

A total of 30 employees (69% female; 39.5 ± 9 years) completed an online questionnaire before and after a 6-week intervention. The intervention comprised one group-based action planning session, using a smart activity tracker for self-monitoring, weekly email reminders, and a healthy living seminar.

RESULTS

Total self-reported sitting time (including occupational and nonoccupational sitting) decreased nonsignificantly on days when working at the office (MΔ = -56 min/d, 95% confidence interval [CI], -128.5 to 17.0) and increased nonsignificantly when working at home (MΔ = 20.5 min/d, 95% CI, -64.5 to 105.5). The program had high acceptability in this participant group.

CONCLUSIONS

Brief self-directed interventions using activity tracker devices show promise and may be highly acceptable in a flexible workplace. Additional strategies may be needed to create change in sedentary behavior.

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.

It's All in the Wrist: Diagnosis and Management of Carpal Tunnel Syndrome

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy accounting for 90% of similar disorders, occurring in 3.8% of the population, common in adults aged 40-60 years, and is associated with an average 32 lost days of work and lost productivity. In addition to occupational exposure, there are several common chronic disorders that can preclude CTS, obesity, diabetes mellitus, rheumatoid arthritis, pregnancy, metabolic syndrome, and thyroid disorder, to name a few. Therefore, it is important for the primary care provider to have knowledge in this syndrome. The purpose of the article is to inform the provider about the etiology, presentation, diagnosis, and treatment of CTS, as well as the implications for job-associated CTS.

Evaluation of AMSTAR to assess the methodological quality of systematic reviews in overviews of reviews of healthcare interventions

BACKGROUND

Overviews of reviews (overviews) compile information from multiple systematic reviews (SRs) to provide a single synthesis of relevant evidence for decision-making. It is recommended that authors assess and report the methodological quality of SRs in overviews-for example, using A MeaSurement Tool to Assess systematic Reviews (AMSTAR). Currently, there is variation in whether and how overview authors assess and report SR quality, and limited guidance is available. Our objectives were to: examine methodological considerations involved in using AMSTAR to assess the quality of Cochrane and non-Cochrane SRs in overviews of healthcare interventions; identify challenges (and develop potential decision rules) when using AMSTAR in overviews; and examine the potential impact of considering methodological quality when making inclusion decisions in overviews.

METHODS

We selected seven overviews of healthcare interventions and included all SRs meeting each overview's inclusion criteria. For each SR, two reviewers independently conducted AMSTAR assessments with consensus and discussed challenges encountered. We also examined the correlation between AMSTAR assessments and SR results/conclusions.

RESULTS

Ninety-five SRs were included (30 Cochrane, 65 non-Cochrane). Mean AMSTAR assessments (9.6/11 vs. 5.5/11; p < 0.001) and inter-rater reliability (AC1 statistic: 0.84 vs. 0.69; "almost perfect" vs. "substantial" using the Landis & Koch criteria) were higher for Cochrane compared to non-Cochrane SRs. Four challenges were identified when applying AMSTAR in overviews: the scope of the SRs and overviews often differed; SRs examining similar topics sometimes made different methodological decisions; reporting of non-Cochrane SRs was sometimes poor; and some non-Cochrane SRs included other SRs as well as primary studies. Decision rules were developed to address each challenge. We found no evidence that AMSTAR assessments were correlated with SR results/conclusions.

CONCLUSIONS

Results indicate that the AMSTAR tool can be used successfully in overviews that include Cochrane and non-Cochrane SRs, though decision rules may be useful to circumvent common challenges. Findings support existing recommendations that quality assessments of SRs in overviews be conducted independently, in duplicate, with a process for consensus. Results also suggest that using methodological quality to guide inclusion decisions (e.g., to exclude poorly conducted and reported SRs) may not introduce bias into the overview process.

Prevalence, risks and severity of musculoskeletal disorder symptoms among administrative employees of a Brazilian company

BACKGROUND

Musculoskeletal disorders (MSD) are common among office workers.

OBJECTIVE

To evaluate the prevalence, risks and symptoms of MSD among office workers of a Brazilian dairy company.

METHODS

Fifty office workers participated in the study. The following evaluations and questionnaires were completed: Rapid Upper Limb Assessment, Strain Index, Muscle Fatigue Assessment, Nordic General Questionnaire, and Oswestry Disability Index.

RESULTS

Seventy-four percent (n = 37) of the participants had MSD symptoms. The back was most commonly affected body part (81% , n = 30), followed by the upper limbs (70% , n = 26). Fifty-three percent of the workers with low back pain had mild to moderate disability, and the risk for the hands, wrists and fingers was moderate. Changes are required to reduce the risk of MSD among the participating office workers.

CONCLUSION

The prevalence of MSD symptoms was high; the back and upper limbs were most commonly affected. Data from the evaluations and questionnaires supplemented each other. The Rapid Upper Limb Assessment and Strain Index were better indicators of risk of MSD symptoms than the Muscle Fatigue Assessment. The participating office workers were exposed to moderate risk of developing MSD due to biomechanical overload and changes are required.

The BASE-Program-A Multidimensional Approach for Health Promotion in Companies

Multidimensional assessments for conducting interventions are needed to achieve positive health effects within companies. BASE is an acronym, consisting of B = "Bedarfsbestimmung" (requirements); A = "Arbeitsplatzorganisation" (organisation of work); S = "Schulung des belastungsverträglichen Alltagshandelns" (coaching preventive behaviour at work); E = "Eigenverantwortung und Selbstwirksamkeit" (self-responsibility and self-efficacy). It is a prevention program designed to avoid and reduce work-related musculoskeletal diseases. It was developed to support prevention strategies within companies. It comprises aspects of health protection, ergonomics, exercise and self-efficacy. A comprehensive assessment will identify strain e.g., musculoskeletal discomforts due to body positions or psychological stress. Moreover, the general health status, preferences and barriers for participating in health promotion programs are evaluated. This analysis leads to practical and goal-oriented recommendations and interventions which suit the needs of companies and employees. These are executed onsite in real workplace situations and involve the introduction of first-hand experience in behavioural change. Therefore, this practical approach enhances the employees' acceptance and self-efficacy for health promotion. This can result in long-term health promoting behaviour. This article presents the outcome and sustainability effects of BASE in three different application fields (logistic, industrial and office workers).

Effects of mouse slant and desktop position on muscular and postural stresses, subject preference and performance in women aged 18-40 years

This study compared muscular and postural stresses, performance and subject preference in women aged 18-40 years using a standard mouse, a vertical mouse and a slanted mouse in three different computer workstation positions. Four tasks were analysed: pointing, pointing-clicking, pointing-clicking-dragging and grasping-pointing the mouse after typing. Flexor digitorum superficialis (FDS) and extensor carpi radialis (ECR) activities were greater using the standard mouse compared to the vertical or slanted mouse. In all cases, the wrist position remained in the comfort zone recommended by standard ISO 11228-3. The vertical mouse was less comfortable and more difficult to use than the other two mice. FDS and ECR activities, shoulder abduction and wrist extension were greater when the mouse was placed next to the keyboard. Performance and subject preference were better with the unrestricted mouse positioning on the desktop. Grasping the mouse after typing was the task that caused the greatest stress. Practitioner Summary: In women, the slanted mouse and the unrestricted mouse positioning on the desktop provide a good blend of stresses, performance and preference. Unrestricted mouse positioning requires no keyboard, which is rare in practice. Placing the mouse in front of the keyboard, rather than next to it, reduced the physical load.

Upper-extremity and neck disorders associated with keyboard and mouse use

Musculoskeletal disorders are frequently related to computer use in the workplace. The aim of this chapter is to provide an overview of the evidence in the literature concerning the putative association between neck, shoulder, and upper-limb disorders and occupational exposure to use of a computer and its devices. We searched the scientific literature via PubMed, using specific search strategies, including substrings tailored to retrieve papers about: (1) occupational etiology; (2) computer use; and (3) different upper-limb disorders. We intended to include, in our evaluation, systematic reviews and relevant, informative papers published later on. We were able to retrieve 11 systematic reviews and 11 informative studies regarding neck, shoulder, and upper-limb disorders. There is limited/insufficient and/or inconsistent evidence indicating that computer work may be associated to neck, shoulder, or distal arm complaints. There is sufficient evidence indicating no association between carpal tunnel syndrome and computer work. There are no studies regarding the use of computers and some neck, shoulder, and upper-limb diseases, such as tennis elbow and trigger finger. Applying the general principles of ergonomics to computer work is probably the correct strategy to pursue, with the aim of maintaining office workers' well-being.

Limitations of A Measurement Tool to Assess Systematic Reviews (AMSTAR) and suggestions for improvement

A Measurement Tool to Assess Systematic Reviews (AMSTAR) is a commonly used tool to assess the quality of systematic reviews; however, modifications are needed to improve its usability, reliability, and validity. In this commentary, we summarize our experience and the experiences of others who have used AMSTAR and provide suggestions for its improvement. We propose that AMSTAR should modify a number of individual items and their instructions and responses to make them more congruent with an assessment of the methodologic quality of systematic reviews. We recommend adding new items and modifying existing items to assess the quality of the body of evidence and to address subgroup and sensitivity analyses. More detailed instructions are needed for scoring individual items across multiple reviewers, and we recommend that a total score should not be calculated. These suggestions need to be empirically tested prior to implementation.

Usage Position and Virtual Keyboard Design Affect Upper-Body Kinematics, Discomfort, and Usability during Prolonged Tablet Typing

Purpose

The increase in tablet usage allows people to perform computer work in non-traditional office environments. The aim of this study was to assess the effects of changes in tablet keyboard design on postures of the upper extremities and neck, discomfort, and usability under different usage positions during prolonged touch-typing.

Methods

Eighteen healthy participants familiar with touch-screen devices were randomized into three usage positions (desk, lap, and bed) and completed six, 60-minute typing sessions using three virtual keyboard designs (standard, wide, split). Electrogoniometers continuously measured the postures of the wrists, elbow, and neck. Body discomfort and system usability were evaluated by questionnaires before and immediately after each typing session.

Results

Separate linear mixed effects models on various postural measures and subjective ratings are conducted with usage position as the between-subject factors, keyboard design and typing duration as the with-in subject factors were conducted. Using the tablet in bed led to more extended wrists but a more natural elbow flexion than the desk position. The angled split virtual keyboard significantly reduced the extent of wrist ulnar deviation than the keyboard with either standard or wide design. However, little difference was observed across the usage position and keyboard design. When the postural data were compared between the middle and end of typing sessions, the wrists, elbow, and neck all exhibited a substantially increased range of joint movements (13% to 38%). The discomfort rating also increased significantly over time in every upper body region investigated. Additionally, the split keyboard design received a higher usability rating in the bed position, whereas participants had more satisfactory experience while using the wide keyboard in the traditional desk setting.

Conclusions

Prolonged use of tablets in non-traditional office environments may result in awkward postures in the upper body that may expose users to greater risks of developing musculoskeletal symptoms. Adequate virtual keyboard designs show the potential to alleviate some postural effects and improve the user experience without changing the tablet form factors.

The effect of a workstation chair and computer screen height adjustment on neck and upper back musculoskeletal pain and sitting comfort in office workers

Aims

To assess the effect of a vertical height adjustment of the chair and visual display unit (VDU) on work-related upper quadrant musculoskeletal pain (WRUQMP) and sitting comfort in office workers. The upper quadrant refers to the occiput, cervical and upper thoracic spine, including the clavicles and scapulae.

Methods

A single subject (N = 1) study, in which the subject serves as her own control, was conducted using the ABC design. An ergonomic workstation adjustment of VDU and chair height was compared to the subject’s usual workstation settings. Pain and sitting comfort was measured using visual analogue scales (VAS). The subject was assessed over three four-week phases as she performed her typical VDU work. The results were compiled and tabulated.

Results

Both the mean and variance in pain intensity decreased after the workstation intervention. A deterioration in sitting comfort was noted.

Conclusion

The vertical height adjustment of the chair and visual display unit may have contributed to a decrease in work-related upper quadrant musculoskeletal pain in this subject. This safe, economical workstation intervention may be a practical management option for the computer user suffering from work-related upper quadrant musculoskeletal pain. Further research into the measurement of comfort whilst sitting at a computer workstation is recommended.

The Health Effects of Passive Smoking: An Overview of Systematic Reviews Based on Observational Epidemiological Evidence

Purpose

We aim to systematically summarize the available epidemiological evidence to identify the impact of environmental tobacco smoke on health.

Methods

A systematic literature search of PubMed, Embase, Web of Science, and Scopus for meta-analyses was conducted through January 2015. We included systematic reviews that investigated the association between passive smoking and certain diseases. Quantitative outcomes of association between passive smoking and the risk of certain diseases were summarized.

Results

Sixteen meta-analyses covering 130 cohort studies, 159 case-control studies, and 161 cross-sectional studies and involving 25 diseases or health problems were reviewed. Passive smoking appears not to be significantly associated with eight diseases or health problems, but significantly elevates the risk for eleven specific diseases or health problems, including invasive meningococcal disease in children (OR 2.18; 95% CI 1.63–2.92), cervical cancer (OR 1.73; 95% CI 1.35–2.21), Neisseria meningitidis carriage (OR 1.68; 95% CI 1.19–2.36), Streptococcus pneumoniae carriage (OR 1.66; 95% CI 1.33–2.07), lower respiratory infections in infancy (OR 1.42; 95% CI 1.33–1.51), food allergy (OR 1.43; 95% CI 1.12–1.83), and so on.

Conclusions

Our overview of systematic reviews of observational epidemiological evidence suggests that passive smoking is significantly associated with an increasing risk of many diseases or health problems, especially diseases in children and cancers.

Carpal tunnel syndrome and computer exposure at work in two large complementary cohorts

OBJECTIVES

The boom in computer use and concurrent high rates in musculoskeletal complaints and carpal tunnel syndrome (CTS) among users have led to a controversy about a possible link. Most studies have used cross-sectional designs and shown no association. The present study used longitudinal data from two large complementary cohorts to evaluate a possible relationship between CTS and the performance of computer work.

SETTINGS AND PARTICIPANTS

The Cosali cohort is a representative sample of a French working population that evaluated CTS using standardised clinical examinations and assessed self-reported computer use. The PrediCTS cohort study enrolled newly hired clerical, service and construction workers in several industries in the USA, evaluated CTS using symptoms and nerve conduction studies (NCS), and estimated exposures to computer work using a job exposure matrix.

PRIMARY AND SECONDARY OUTCOME MEASURES

During a follow-up of 3-5 years, the association between new cases of CTS and computer work was calculated using logistic regression models adjusting for sex, age, obesity and relevant associated disorders.

RESULTS

In the Cosali study, 1551 workers (41.8%) completed follow-up physical examinations; 36 (2.3%) participants were diagnosed with CTS. In the PrediCTS study, 711 workers (64.2%) completed follow-up evaluations, whereas 31 (4.3%) had new cases of CTS. The adjusted OR for the group with the highest exposure to computer use was 0.39 (0.17; 0.89) in the Cosali cohort and 0.16 (0.05; 0.59) in the PrediCTS cohort.

CONCLUSIONS

Data from two large cohorts in two different countries showed no association between computer work and new cases of CTS among workers in diverse jobs with varying job exposures. CTS is far more common among workers in non-computer related jobs; prevention efforts and work-related compensation programmes should focus on workers performing forceful hand exertion.

Postural dynamism during computer mouse and keyboard use: A pilot study

Prolonged sedentary computer use is a risk factor for musculoskeletal pain. The aim of this study was to explore postural dynamism during two common computer tasks, namely mouse use and keyboard typing. Postural dynamism was described as the total number of postural changes that occurred during the data capture period. Twelve participants were recruited to perform a mouse and a typing task. The data of only eight participants could be analysed. A 3D motion analysis system measured the number of cervical and thoracic postural changes as well as, the range in which the postural changes occurred. The study findings illustrate that there is less postural dynamism of the cervical and thoracic spinal regions during computer mouse use, when compared to keyboard typing.

Association between work-related biomechanical risk factors and the occurrence of carpal tunnel syndrome: an overview of systematic reviews and a meta-analysis of current research

BACKGROUND

Occupational risks for carpal tunnel syndrome (CTS) have been examined in various occupations, and several systematic reviews (SRs) have been published on this topic. There has been no critical appraisal or synthesis of the evidence in the SRs. The aims of this study are (1) to synthesise the observational evidence and evaluate the methodological quality of SRs that assess the effect of biomechanical risk factors on the development of CTS in workers, (2) to provide an update of current primary research on this association, (3) to assess a potential dose-response relationship.

METHODS

We searched MEDLINE, EMBASE, CINAHL, the Cochrane Library and the reference lists of articles. The first step covered SRs (1998-2014), and the second step covered current primary studies (2011-2014). The methodological quality of the SRs was evaluated by using the AMSTAR-R tool; primary studies were assessed using a list of 20 items. A qualitative approach was used for synthesising evidence. In addition, we undertook a meta-analysis of the primary studies to determine risk ratios in the dose-response relationship.

RESULTS

We identified ten SRs that covered a total of 143 original studies. Seven primary studies met the criteria for inclusion, of which four provided longitudinal data. We found high quality of evidence for risk factors such as repetition, force and combined exposures. Moderate quality of evidence was observed for vibration, and low quality of evidence was found for wrist postures. An association between computer use and CTS could not be established. Recent primary studies supported the existence of a significant relationship between CTS and repetition, force and combined exposure. The meta-analysis of current research revealed a dose-response relationship between CTS and the American Conference of Governmental Industrial Hygienists' (ACGIH) threshold limit value (TLV) for hand-activity level (HAL). Those between the action limit and TLV and above TLV had RR of 1.5 (95% CI 1.02-2.31) and RR 2.0 (95% CI 1.46-2.82), respectively.

CONCLUSIONS

Occupational biomechanical factors play a substantial role in the causation of CTS. Data from current primary studies on dose-response suggest that the risk of CTS increases with the ACGIH TLV levels.

Brachial plexopathy: a case-control study of the relation to physical exposures at work

BACKGROUND

Work-related upper limb disorders constitute a diagnostic challenge. However, patterns of neurological abnormalities that reflect brachial plexus dysfunction are frequent in limbs with pain, weakness and/or numbness/tingling. There is limited evidence about the association between occupational physical exposures and brachial plexopathy.

METHODS

80 patients with brachial plexopathy according to defined criteria and 65 controls of similar age and sex without upper limb complaints were recruited by general practitioners. Patients and controls completed a questionnaire on physical and psychosocial work-exposures and provided psychophysical ratings of their perceived exposures. The exposures of cases and controls were compared by a Wilcoxon rank sum test. Odds ratios and dose-response relationships were studied by logistic regression.

RESULTS

Whether assessed as the extent during the workday or days/week, most physical exposures, in particular upper limb posture and repetition, were significant risk indicators with clear dose-response relationships. These findings were supported by psychophysical responses that also identified perceived work pace and the use of force as risk indicators. The identified psychosocial relations were limited to measures reflecting physical exposures.

CONCLUSIONS

While the identified risk indicators have previously been associated to upper limb symptoms as well as to diagnosed disorders other than brachial plexopathy, this study indicates an association between physical and work-exposures and brachial plexopathy. Longitudinal studies should be conducted in order to exclude bias from information and selection, both of which may occur with the applied case-control design.

The relationship between sitting posture and seated-related upper quadrant musculoskeletal pain in computing South African adolescents: A prospective study

BACKGROUND

There is evidence that consistent sitting for prolonged periods is associated with upper quadrant musculoskeletal pain (UQMP). It is unclear whether postural alignment is a significant risk factor.

OBJECTIVE AND DESIGN

The aim of the prospective study (2010-2011) was to ascertain if three-dimensional sitting postural angles, measured in a real-life school computer classroom setting, predict seated-related UQMP.

METHOD

Asymptomatic Grade 10 high-school students, aged 15-17 years, undertaking Computer Application Technology, were eligible to participate. Using the 3D Posture Analysis Tool, sitting posture was measured while students used desk-top computers. Posture was reported as five upper quadrant angles (Head flexion, Neck flexion; Craniocervical angle, Trunk flexion and Head lateral bending). The Computer Usage Questionnaire measured seated-related UQMP and hours of computer use. The Beck Depression Inventory and the Multidimensional Anxiety Scale for Children assessed psychosocial factors. Sitting posture, computer use and psychosocial factors were measured at baseline. UQMP was measured at six months and one-year follow-up.

RESULTS

211, 190 and 153 students participated at baseline, six months and one-year follow-up respectively. 34.2% students complained of seated-related UQMP during the follow-up period. Increased head flexion (HF) predicted seated-related UQMP developing over time for a small group of students with pain scores greater than the 90th pain percentile, adjusted for age, gender, BMI, computer use and psychosocial factors (p = 0.003). The pain score increased 0.22 points per 1° increase in HF.

CONCLUSIONS

Classroom ergonomics and postural hygiene should therefore focus on reducing large HF angles among computing adolescents.

Risk factors for carpal tunnel syndrome related to the work organization: a prospective surveillance study in a large working population

The study aimed to determine the risk factors for incident carpal tunnel syndrome (CTS) in a large working population, with a special focus on factors related to work organization. In 2002-2005, 3710 workers were assessed and, in 2007-2010, 1611 were re-examined. At baseline all completed a self-administered questionnaire about personal/medical factors and work exposure. CTS symptoms and physical examination signs were assessed by a standardized medical examination at baseline and follow-up. The risk of "symptomatic CTS" was higher for women (OR = 2.9 [1.7-5.2]) and increased linearly with age (OR = 1.04 [1.00-1.07] for 1-year increment). Two work organizational factors remained in the multivariate risk model after adjustment for the personal/medical and biomechanical factors: payment on a piecework basis (OR = 2.0, 95% CI 1.1-3.5) and work pace dependent on automatic rate (OR = 1.9, 95% CI 0.9-4.1). Several factors related to work organization were associated with incident CTS after adjustment for potential confounders.

The Brazilian Portuguese version of the revised Maastricht Upper Extremity Questionnaire (MUEQ-Br revised): translation, cross-cultural adaptation, reliability, and structural validation

BACKGROUND

Complaints of the arm, neck, and shoulders (CANS) have a multifactorial etiology, and, therefore, their assessment should consider both work-related ergonomic and psychosocial aspects. The Maastricht Upper Extremity Questionnaire (MUEQ) is one of a few specific tools available to evaluate the nature and occurrence of CANS in computer-office workers and the impact of psychosocial and ergonomic aspects on work conditions. The purpose of the present study was to perform a translation and cross-cultural adaptation of the MUEQ to Brazilian Portuguese and verify the reliability, internal consistency, and structural validity of the MUEQ in Brazilian computer-office workers.

METHODS

The cross-cultural adaptation consisted of five stages (forward translation of the MUEQ to Brazilian Portuguese, synthesis of the translation, back-translation, expert committee meeting, and the pre-final-version test). In the pre-final-version test, 55 computer-office workers participated. For reproducibility, a sample of 50 workers completed the questionnaire twice within a one-week interval. A sample of 386 workers from the University of São Paulo (mean age = 37.44 years; 95% confidence interval: 36.50-38.38; 216 women and 170 men) participated on the structural validation and internal consistency analysis. Intraclass correlation coefficient was used for the statistical analysis of reproducibility, Cronbach's alpha was used for internal consistency, and confirmatory factor analysis was used for structural validity.

RESULTS

The calculation of internal consistency, reproducibility, and cross validation provided evidence of reliability and lack of redundancy. The psychometric properties of the modified MUEQ-Br revised were assessed using confirmatory factor analysis, which revealed 6 factors and 41 questions. For this model, the comparative fit index (CFI), goodness-of-fit index (GFI), and non-normed fit index (NNFI) each achieved 0.90, and the consistent Akaike information criterion (CAIC), chi-square, expected cross-validation index (ECIV), and root mean square error of approximation (RMSEA) demonstrated better values.

CONCLUSIONS

The results provide a basis for using the 41-item MUEQ-Br revised for the assessment of computer-office workers' perceptions of the psychosocial and ergonomic aspects of CANS and musculoskeletal-complaint characterization.