The effect of forearm support on musculoskeletal discomfort during call centre work

Investigation of the multi-component ergonomics intervention effects on improving musculoskeletal outcomes and speech communication: A case study in open-plan offices

BACKGROUND

Office workers are at high risk of developing musculoskeletal symptoms (MSS) due to improper workstations. Open-plan bank office employees must communicate with bank clerks properly and perform financial activity precisely, but noise is a factor that disrupts their communication. Therefore, MSS and annoying noise are two of the main problems in open-plan offices.

OBJECTIVE

This study evaluated the effects of a multi-component intervention involving individual (employee ergonomics training) and physical (improvements in workstation design and work environment) ergonomic factors on musculoskeletal outcomes and speech communication in open-plan environments.

METHODS

A preliminary survey was carried out to investigate the overall ergonomics problems, the tasks and time analysis, workstations setup, the prevalence of MSS (Nordic Musculoskeletal Questionnaire), physical discomfort (Visual Analogue Scale [VAS]), and posture (assessed by Rapid Upper Limb Assessment [RULA] method), environmental status (measurement of noise), and speech intelligibility (assessed by Speech Interference Level [SIL] method based on ISO 9921). The multi-component interventions were performed afterward based on the data collected. A baseline assessment and a 9-month follow-up assessment were conducted.

RESULTS

The results showed a significant decrease in the prevalence of musculoskeletal complaints (shoulders, elbows, and low back), physical discomfort, and awkward working postures after the intervention. A considerable improvement was also found in speech intelligibility post-intervention. The post-intervention questionnaire survey also indicated that employees generally favored the redesigned workstations.

CONCLUSION

The results support the effectiveness of implementing multi-component interventions in open-plan bank offices to improve musculoskeletal complaints and speech communication.

Assessing the effectiveness of an ergonomics intervention program with a participatory approach: ergonomics settlement in an Iranian steel industry

PURPOSE

Work-related musculoskeletal disorders (WMSDs) are common occupational problems affecting the health and productivity of workers worldwide. Ergonomic intervention programs (EIPs) can play an effective role in preventing these disorders in the workplace. Assessing the effectiveness of an EIP is a challenge faced by both industries and researchers. This study was aimed at assessing the effectiveness of an EIP on human resources productivity (HRP), musculoskeletal disorders (MSDs), general health and occupational fatigue in a steel industry.

METHODS

This study was conducted in a steel industry in Isfahan, Iran, between 2018 and 2021. To assess the effectiveness of the EIP with a participatory approach, training and redesign of workstations, the criteria of HRP, MSDs, general health and occupational fatigue were investigated before and after the intervention, using HRP Questionnaire, Nordic musculoskeletal questionnaire (NMQ), 28-item General Health Questionnaire (28-GHQ), Swedish Occupational Fatigue Inventory (SOFI-20) and Occupational Fatigue/Exhaustion Recovery (OFER-15) Questionnaire, as data collection tools, respectively.

RESULTS

The implementation of EIP in the studied industry significantly led to an increase in HRP (p < 0.05). The prevalence of MSDs decreased significantly in most regions of the body after the interventions (p < 0.001). In addition, the program significantly improved general health (p < 0.001) and reduced occupational fatigue among employees (p < 0.001).

CONCLUSIONS

The implementation of EIP was significantly effective in working conditions improvement. Therefore, implementing EIP with participatory approach, workforce training, as well as redesigning of workstations are recommended in industries.

Systematic Review and Meta-Analysis Suggest Strength Training and Workplace Modifications May Reduce Neck Pain in Office Workers

OBJECTIVE

Neck pain is a burdensome musculoskeletal disorder in office workers. Workplace interventions aim to prevent and minimize the effect of neck pain and improve work quality. However, the summed effect of workplace interventions on neck pain in office workers remains unclear. This systematic review with meta-analysis and meta-regression evaluated the summed effect of workplace interventions on neck pain in office workers.

METHODS

We searched 7 electronic databases to January 2020 for randomized clinical trials. We selected studies, independently extracted data, and assessed risk of bias. Meta-analyses were carried out along with normalized trend plots.

RESULTS

Twenty-nine trials, including 8 of high quality, met our inclusion criteria. Normalized trend plots indicate that neck strengthening demonstrated the sharpest decrease in pain scores. The results of pre- and post-outcome measurement of the effect of activity performance and workplace modification showed significant improvements in self-reported neck pain (P ≤ 0.001). Meta-regression was used to evaluate the effect of time, but it was not significant.

CONCLUSIONS

There is low-quality evidence that neck strengthening and tailored workstation modifications are effective at reducing neck pain in office workers. Further high-quality research methodology, including clinicians, is important to evaluate this summed effect.

Mouse with your arm™: Facilitating forearm support using the chair armrest to prevent and mitigate musculoskeletal disorders

BACKGROUND

Musculoskeletal disorders (MSDs) can be prevented by avoiding trauma caused by poor posture, compression, force, and repetition. Neutral postures are recommended to avoid MSDs.

OBJECTIVE

This study introduces Mouse With Your Arm™ (MWYA) methodology which promotes sitting back in a chair, using the chair's armrest for forearm support at relaxed elbow height, matching surface and armrest height, and keeping the mouse on the surface edge. This position allows optimal task chair use, facilitates movement and neutral postures, avoids compression and contact stress, and is effective in mitigating MSDs.

METHOD

MWYA was applied and measured in the field for more 23 years providing over 3,500 individualized assessments to integrate a participant's unique characteristics, reported health concerns, tasks, tools, and environment to achieve and sustain whole-body neutral and comfortable working postures.

RESULTS

Previous research has consistently recommended use of forearm support by a desk, apparatus, or wrist rest, and resulted in non-neutral, static postures and measured health consequences. By using armrests for support, MWYA avoids the potential of MSDs as can be caused by these previously endorsed postures.

CONCLUSION

By applying the five MWYA principles, computer users comprehend neutral posture and put forth the effort essential to creating healthy human computer relationships.

Exercise alone and exercise combined with education both prevent episodes of low back pain and related absenteeism: systematic review and network meta-analysis of randomised controlled trials (RCTs) aimed at preventing back pain

OBJECTIVES

We aimed to investigate which prevention strategies for low back pain (LBP) are most effective.

DESIGN

We completed a Bayesian network meta-analysis to summarise the comparative effectiveness of LBP prevention strategies. The primary outcomes were an episode of LBP and LBP-associated work absenteeism represented as ORs with associated 95% credibility intervals (CrIs). We ranked all prevention strategies with surface under the cumulative ranking curve (SUCRA) analysis.

DATA SOURCES

PubMed, EMBASE and CENTRAL databases were searched along with manual searches of retrieved articles. We only included randomised controlled trials (RCTs) that reported an episode of LBP and/or LBP-associated work absenteeism evaluating LBP prevention strategies were included.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Data were independently extracted by two investigators, and RCT quality was assessed using the Cochrane Risk of Bias tool.

RESULTS AND SUMMARY

Forty RCTs were included. Exercise combined with education (OR: 0.59, CrI: 0.41 to 0.82) and exercise alone (OR: 0.59, CrI: 0.36 to 0.92) both prevented LBP episodes; exercise combined with education and education alone both had large areas under the curve (SUCRA: 81.3 and 79.4, respectively). Additionally, exercise (OR: 0.04, CrI: 0.00 to 0.34) prevented LBP-associated work absenteeism, with exercise and the combination of exercise and education ranking highest (SUCRA: 99.0 and 60.2, respectively).

CONCLUSIONS

Exercise alone and exercise combined with education can prevent episodes of LBP and LBP-related absenteeism.

TRIAL REGISTRATION NUMBER

PROSPERO 42017056884.

Effect of a posture correction-based intervention on musculoskeletal symptoms and fatigue among control room operators

This study was conducted to examine the effect of a posture correction-based intervention (with a biofeedback device) on the occurrence of musculoskeletal symptoms (MSS) and fatigue among control room operators in a petrochemical plant in Iran. A total of 188 office workers (91 in the case group and 97 in the control group) participated at baseline as well as at 6- and 12-month follow-up. A questionnaire survey (including the Nordic Musculoskeletal Questionnaire and Multidimensional Fatigue Inventory) and direct observations of working postures by using the Rapid Upper Limb Assessment (RULA) method were used. The occurrence of MSS in the shoulders, upper back, neck, and low back areas, as well as the mental and physical dimensions of fatigue were found to be the most common problems. The results showed considerable improvements in working postures (in the neck, trunk, and RULA grand scores) and the occurrence of MSS (particularly in the neck, shoulders, and upper back and low back areas) and fatigue (in particular the mental and physical aspects) after the intervention. The overall mean RULA grand score for the case group was significantly decreased after the intervention (mean scores of 5.1, 4.4, and 4.6 at pre-intervention, post-intervention 1, and post-intervention 2, respectively). A total of 81 operators (89.0%) reported some kind of MSS at baseline, which were reduced to 75 operators (82.4%) and 77 operators (84.6%) at post-interventions 1 and 2, respectively. Significant differences were also found between the pre- and post-intervention scores for the physical fatigue (mean of 12.19, 10.16, and 9.99 at pre-intervention, post-intervention 1, and post-intervention 2, respectively) and mental fatigue (mean of 14.03, 12.05, and 12.16 at pre-intervention, post-intervention 1, and post-intervention 2, respectively) dimensions. The findings confirm the effectiveness of this low-cost, simple, and easy-to-use ergonomic intervention.

Workplace-Based Interventions for Neck Pain in Office Workers: Systematic Review and Meta-Analysis

Background

At present, there is no consolidated evidence for workplace-based interventions for the prevention and reduction of neck pain in office workers.

Purpose

The purpose of this review was to investigate the effectiveness of workplace-based interventions for neck pain in office workers.

Data Sources

MEDLINE, PEDro, CINAHL, and CENTRAL were searched for trials published since inception and before May 31, 2016.

Study Selection

Randomized controlled trials (RCTs) were considered when they met the following criteria: population consisted of office workers, intervention(s) was performed at the workplace, outcome measures included neck and/or neck/shoulder pain intensity and incidence/prevalence, and comparator groups included no/other intervention.

Data Extraction

Data were extracted by 1 reviewer using predefined data fields and checked by a second reviewer. Risk of bias was assessed by 2 independent reviewers using the 2015 Cochrane Back and Neck Group guidelines. Evidence quality was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation system.

Data Synthesis

Twenty-seven RCTs were included. There was moderate-quality evidence that neck/shoulder strengthening exercises and general fitness training were effective in reducing neck pain in office workers who were symptomatic, although the effect size was larger for strengthening exercises. Greater effects were observed with greater participation in exercise. Ergonomic interventions were supported by low-quality evidence.

Limitations

Data could not be obtained from some studies for meta-analysis and assessment of risk of bias. Reporting bias might have been present because only studies in the English language were included.

Conclusions

Workplace-based strengthening exercises were effective in reducing neck pain in office workers who were symptomatic, and the effect size was larger when the exercises were targeted to the neck/shoulder. Future RCTs of ergonomic interventions targeted at office workers who are symptomatic are required. More research on neck pain prevention is warranted.

A data-driven approach to modeling physical fatigue in the workplace using wearable sensors

Wearable sensors are currently being used to manage fatigue in professional athletics, transportation and mining industries. In manufacturing, physical fatigue is a challenging ergonomic/safety "issue" since it lowers productivity and increases the incidence of accidents. Therefore, physical fatigue must be managed. There are two main goals for this study. First, we examine the use of wearable sensors to detect physical fatigue occurrence in simulated manufacturing tasks. The second goal is to estimate the physical fatigue level over time. In order to achieve these goals, sensory data were recorded for eight healthy participants. Penalized logistic and multiple linear regression models were used for physical fatigue detection and level estimation, respectively. Important features from the five sensors locations were selected using Least Absolute Shrinkage and Selection Operator (LASSO), a popular variable selection methodology. The results show that the LASSO model performed well for both physical fatigue detection and modeling. The modeling approach is not participant and/or workload regime specific and thus can be adopted for other applications.

Work-Related Musculoskeletal Disorders and Risk Factors among Chinese Medical Staff of Obstetrics and Gynecology

Medical staff in the department of obstetrics and gynecology are a group of professionals reportedly at high risk of work-related musculoskeletal disorders (WMSD), however, little is known about the current status of this problem in China. The aim of this study was to investigate prevalence and risk factors of work-related musculoskeletal disorders among this population in China. A self-developed questionnaire was distributed to 1017 obstetrics and gynecology practitioners to collect information on musculoskeletal symptoms and relevant factors. Prevalence and severity of work-related musculoskeletal disorders in different parts of the body were calculated and the relationship between personal and ergonomic factors and work-related musculoskeletal disorders was analyzed using Chi-square test and unconditional logistic regression models. The results indicated a high prevalence of 85.5% among the subjects, with the shoulder (n = 575, 62.0%), neck (n = 560, 60.3%) and lower back (n = 504, 54.3%) being the three most affected regions. Individual, postural, work-environmental as well as psychosocial factors were recognized to be associated with WMSDs in different body parts. Therefore, attention must be given to the problem of musculoskeletal disorders among Chinese obstetrics and gynecology staff. It is recommended to develop good life habits, improve work environment, adjust work organization as well as train on proper postures in their daily operation.

Effectiveness of workplace interventions in the prevention of upper extremity musculoskeletal disorders and symptoms: an update of the evidence

The burden of disabling musculoskeletal pain and injuries (musculoskeletal disorders, MSDs) arising from work-related causes in many workplaces remains substantial. There is little consensus on the most appropriate interventions for MSDs. Our objective was to update a systematic review of workplace-based interventions for preventing and managing upper extremity MSD (UEMSD). We followed a systematic review process developed by the Institute for Work & Health and an adapted best evidence synthesis. 6 electronic databases were searched (January 2008 until April 2013 inclusive) yielding 9909 non-duplicate references. 26 high-quality and medium-quality studies relevant to our research question were combined with 35 from the original review to synthesise the evidence on 30 different intervention categories. There was strong evidence for one intervention category, resistance training, leading to the recommendation: Implementing a workplace-based resistance training exercise programme can help prevent and manage UEMSD and symptoms. The synthesis also revealed moderate evidence for stretching programmes, mouse use feedback and forearm supports in preventing UEMSD or symptoms. There was also moderate evidence for no benefit for EMG biofeedback, job stress management training, and office workstation adjustment for UEMSD and symptoms. Messages are proposed for both these and other intervention categories.

The Effects of Forearm Support on Upper Body for People in Front of Monitor: A Meta-Analysis

With the ever-growing number of people who work at visual display terminals, the work-related musculoskeletal disorders of the upper body are believed to be an important problem all over the world. The forearm support, which can keep the forearm and wrist in biomechanical posture, is a possible protective factor of the development of upper body syndrome. This meta-analysis examines the efficacy of forearm support in reducing upper body syndrome. The Cochrane Library, EMBASE, Ovid, ScienceDirect, SpringerLink, Google Scholar, CNKI database, and Wanfang database were searched from inception until May 29, 2013. Relevant studies were included after the screening of title, abstract, and the full text. Impact of bias was assessed independently by 2 authors. Four studies that met all the inclusion criteria were included finally. The combined results based on all studies suggested that statistically the forearm support had a nonsignificant effect on upper body syndrome (odds ratio [OR] = 0.70, 95% confidence interval [CI]: 0.49, 1.02). The result of subgroup analysis suggested that forearm support has a significant effect on neck or shoulder syndrome (OR = 0.70, 95% CI: 0.43, 1.14) and the effect on upper extremity syndrome (OR = 0.76, 95% CI: 0.49, 1.19) is not significant. This meta-analysis suggested that the forearm support had statistically nonsignificant effect on preventing upper body syndrome on the whole.

Psychological Care, Patient Education, Orthotics, Ergonomics and Prevention Strategies for Neck Pain: An Systematic Overview Update as Part of the ICON Project

OBJECTIVES

To conduct an overview on psychological interventions, orthoses, patient education, ergonomics, and 1⁰/2⁰ neck pain prevention for adults with acute-chronic neck pain.

SEARCH STRATEGY

Computerized databases and grey literature were searched (2006-2012).

SELECTION CRITERIA

Systematic reviews of randomized controlled trials (RCTs) on pain, function/disability, global perceived effect, quality-of-life and patient satisfaction were retrieved.

DATA COLLECTION & ANALYSIS

Two independent authors selected articles, assessed risk of bias using AMSTAR tool and extracted data. The GRADE tool was used to evaluate the body of evidence and an external panel to provide critical review.

MAIN RESULTS

We retrieved 30 reviews (5-9 AMSTAR score) reporting on 75 RCTs with the following moderate GRADE evidence. For acute whiplash associated disorder (WAD), an education video in emergency rooms (1RCT, 405participants] favoured pain reduction at long-term follow-up thus helping 1 in 23 people [Standard Mean Difference: -0.44(95%CI: -0.66 to -0.23)). Use of a soft collar (2RCTs, 1278participants) was not beneficial in the long-term. For chronic neck pain, a mind-body intervention (2RCTs, 1 meta-analysis, 191participants) improved short-term pain/function in 1 of 4 or 6 participants. In workers, 2-minutes of daily scapula-thoracic endurance training (1RCT, 127participants) over 10 weeks was beneficial in 1 of 4 participants. A number of psychosocial interventions, workplace interventions, collar use and self-management educational strategies were not beneficial.

REVIEWERS' CONCLUSIONS

Moderate evidence exists for quantifying beneficial and non-beneficial effects of a limited number of interventions for acute WAD and chronic neck pain. Larger trials with more rigorous controls need to target promising interventions.

Shoulder and neck muscle activities during typing with articulating forearm support at different heights

Use of forearm support is known to reduce physical stress of computer users, but research about how to properly position the forearm support is insufficient. This study was aimed to determine whether the height of forearm support influences muscular loads during typing. Twenty four subjects performed a typing task with a pair of articulating forearm support at three different heights as well as without any support, while shoulder, neck and forearm muscle activities and posture data were recorded. Typing with the support at resting elbow height produced significantly (p < 0.05) lower shoulder and neck muscle activities than that of no support condition. Typing with the support at heights higher than the resting elbow height produced significantly greater shoulder and neck muscle activities compared to the no support condition. Results suggest that forearm support can help computer users lessen physical stress in typing, but only when the supports are positioned at resting elbow height. Practitioner Summary: Use of forearm support is known to alleviate physical stress of PC users in computer works such as typing. This experimental study addressed the importance of proper positioning of forearm support by comparing neck and upper extremity muscle activities between conditions with varying heights of forearm support in keyboard typing.

Ergonomic design and training for preventing work-related musculoskeletal disorders of the upper limb and neck in adults

BACKGROUND

Work-related upper limb and neck musculoskeletal disorders (MSDs) are one of the most common occupational disorders around the world. Although ergonomic design and training are likely to reduce the risk of workers developing work-related upper limb and neck MSDs, the evidence is unclear.

OBJECTIVES

To assess the effects of workplace ergonomic design or training interventions, or both, for the prevention of work-related upper limb and neck MSDs in adults.

SEARCH METHODS

We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL, AMED, Web of Science (Science Citation Index), SPORTDiscus, Cochrane Occupational Safety and Health Review Group Database and Cochrane Bone, Joint and Muscle Trauma Group Specialised Register to July 2010, and Physiotherapy Evidence Database, US Centers for Disease Control and Prevention, the National Institute for Occupational Safety and Health database, and International Occupational Safety and Health Information Centre database to November 2010.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of ergonomic workplace interventions for preventing work-related upper limb and neck MSDs. We included only studies with a baseline prevalence of MSDs of the upper limb or neck, or both, of 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 intervention and outcome in the meta-analysis. We assessed the overall quality of the evidence for each comparison using the GRADE approach.

MAIN RESULTS

We included 13 RCTs (2397 workers). Eleven studies were conducted in an office environment and two in a healthcare setting. We judged one study to have a low risk of bias. The 13 studies evaluated effectiveness of ergonomic equipment, supplementary breaks or reduced work hours, ergonomic training, a combination of ergonomic training and equipment, and patient lifting interventions for preventing work-related MSDs of the upper limb and neck in adults.Overall, there was moderate-quality evidence that arm support with alternative mouse reduced the incidence of neck/shoulder disorders (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/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 was also moderate-quality evidence that the incidence of neck/shoulder and right upper limb disorders were not reduced when comparing alternative mouse and conventional mouse (neck/shoulder RR 0.62; 95% CI 0.19 to 2.00; right upper limb RR 0.91; 95% CI 0.48 to 1.72), arm support and no arm support with conventional mouse (neck/shoulder RR 0.67; 95% CI 0.36 to 1.24; right upper limb RR 1.09; 95% CI 0.51 to 2.29), and alternative mouse with arm support and conventional mouse with arm support (neck/shoulder RR 0.58; 95% CI 0.30 to 1.12; right upper limb RR 0.92; 95% CI 0.36 to 2.36).There was low-quality evidence that using an alternative mouse with arm support compared to conventional mouse with arm support reduced neck/shoulder discomfort (SMD -0.39; 95% CI -0.67 to -0.10). There was low- to very low-quality evidence that other interventions were not effective in reducing work-related upper limb and neck MSDs in adults.

AUTHORS' CONCLUSIONS

We found moderate-quality evidence to suggest that the use of arm support with alternative mouse may reduce the incidence of neck/shoulder MSDs, but not right upper limb MSDs. Moreover, we found moderate-quality evidence to suggest that the incidence of neck/shoulder and right upper limb MSDs is not reduced when comparing alternative and conventional mouse with and without arm support. However, given there were multiple comparisons made involving a number of interventions and outcomes, high-quality evidence is needed to determine the effectiveness of these interventions clearly. While we found very-low- to low-quality evidence to suggest that other ergonomic interventions do not prevent work-related MSDs of the upper limb and neck, this was limited by the paucity and heterogeneity of available studies. This review highlights the need for high-quality RCTs examining the prevention of MSDs of the upper limb and neck.

Active Handrest: A large workspace tool for precision manipulation

To address the limited dexterous workspace of the human hand, we have developed the Active Handrest. This device assists in precision manipulation tasks by extending a user’s dexterous workspace while providing ergonomic support for reduced fatigue. People use handrests to complete dexterous activities as routine as providing a signature. However, the dexterous workspace of the statically supported hand is somewhat limited. By providing consistent support over large workspaces the Active Handrest could be useful for performing precision tasks, such as surgery, upper limb rehabilitation, and machining. Our prototype Active Handrest is a planar, human–machine interface that provides support for the user’s wrist and arm while allowing the user to retain complete control over a grasped tool or manipulated device. The Active Handrest uses force input from the user’s hand, position input from a grasped tool, or a combination of these inputs. The device’s controller then converts the input(s) into handrest motions. In this paper we describe our novel device prototype and establish a baseline for its performance. Preliminary experiments were conducted to investigate the effects of control input, velocity limits, and user experience. Subsequent experiments compared the Active Handrest to various other support conditions. Use of the Active Handrest was found to significantly reduce task error and provided better speed-accuracy performance than the other tested support methods.

Evaluation of a dynamic armrest for hydraulic-actuation controller use

The efficacy of a newly designed dynamic armrest was evaluated during joystick operation of a typical North American hydraulic-actuation joystick. The dynamic design was evaluated against a stationary armrest condition as well as no armrest condition. Electromyography (EMG) and subjective measurements were used to make the evaluation. The dynamic armrest, which mimics the natural pendulation of a joystick operator's arm in the forward and backward directions, was shown to significantly decrease the muscular activation in the upper trapezius, posterior deltoid, and anterior deltoid (p ≤ 0.01) over a stationary armrest. A questionnaire revealed that subjects significantly (p = 0.01) preferred the dynamic armrest design over either a standard armrest or no armrest with 17 of 21 operators preferring the dynamic armrest. Ratings from the questionnaire indicated that subjects felt that the dynamic armrest required less effort, was more comfortable, and was more effective than either of the other two armrest conditions.

Workplace interventions for neck pain in workers

BACKGROUND

Musculoskeletal disorders are the most common cause of disability in many industrial countries. Recurrent and chronic pain accounts for a substantial portion of workers' absenteeism. Neck pain seems to be more prominent in the general population than previously known.

OBJECTIVES

To determine the effectiveness of workplace interventions (WIs) in adult workers with neck pain.

SEARCH STRATEGY

We searched: CENTRAL (The Cochrane Library 2009, issue 3), and MEDLINE, EMBASE, CINAHL, PsycINFO, ISI Web of Science, OTseeker, PEDro to July 2009, with no language limitations;screened reference lists; and contacted experts in the field.  

SELECTION CRITERIA

We included randomised controlled trials (RCT), in which at least 50% of the participants had neck pain at baseline and received interventions conducted at the workplace.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed risk of bias. Authors were contacted for missing information. Since the interventions varied to a large extend, International Classification of Functioning, Disability and Health (ICF) terminology was used to classify the intervention components. This heterogeneity restricted pooling of data to only one meta-analysis of two studies.

MAIN RESULTS

We identified 1995 references and included10 RCTs (2745 workers). Two studies were assessed with low risk of bias. Most trials (N = 8) examined office workers. Few workers were sick-listed. Thus, WIs were seldom designed to improve return-to-work. Overall, there was low quality evidence that showed no significant differences between WIs and no intervention for pain prevalence or severity. If present, significant results in favour of WIs were not sustained across follow-up times. There was moderate quality evidence (1 study, 415 workers) that a four-component WI was significantly more effective in reducing sick leave in the intermediate-term (OR 0.56, 95% CI 0.33 to 0.95), but not in the short- (OR 0.83, 95% CI 0.52 to 1.34) or long-term (OR 1.28, 95% CI 0.73 to 2.26). These findings might be because only a small proportion of the workers were sick-listed.

AUTHORS' CONCLUSIONS

Overall, this review found low quality evidence that neither supported nor refuted the benefits of any specific WI for pain relief and moderate quality evidence that a multiple-component intervention reduced sickness absence in the intermediate-term, which was not sustained over time. Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate. There is an urgent need for high quality RCTs with well designed WIs.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

On functional motor adaptations: from the quantification of motor strategies to the prevention of musculoskeletal disorders in the neck-shoulder region

BACKGROUND

Occupations characterized by a static low load and by repetitive actions show a high prevalence of work-related musculoskeletal disorders (WMSD) in the neck-shoulder region. Moreover, muscle fatigue and discomfort are reported to play a relevant initiating role in WMSD.

AIMS

To investigate relationships between altered sensory information, i.e. localized muscle fatigue, discomfort and pain and their associations to changes in motor control patterns.

MATERIALS & METHODS

In total 101 subjects participated. Questionnaires, subjective assessments of perceived exertion and pain intensity as well as surface electromyography (SEMG), mechanomyography (MMG), force and kinematics recordings were performed.

RESULTS

Multi-channel SEMG and MMG revealed that the degree of heterogeneity of the trapezius muscle activation increased with fatigue. Further, the spatial organization of trapezius muscle activity changed in a dynamic manner during sustained contraction with acute experimental pain. A graduation of the motor changes in relation to the pain stage (acute, subchronic and chronic) and work experience were also found. The duration of the work task was shorter in presence of acute and chronic pain. Acute pain resulted in decreased activity of the painful muscle while in subchronic and chronic pain, a more static muscle activation was found. Posture and movement changed in the presence of neck-shoulder pain. Larger and smaller sizes of arm and trunk movement variability were respectively found in acute pain and subchronic/chronic pain. The size and structure of kinematics variability decreased also in the region of discomfort. Motor variability was higher in workers with high experience. Moreover, the pattern of activation of the upper trapezius muscle changed when receiving SEMG/MMG biofeedback during computer work.

DISCUSSION

SEMG and MMG changes underlie functional mechanisms for the maintenance of force during fatiguing contraction and acute pain that may lead to the widespread pain seen in WMSD. A lack of harmonious muscle recruitment/derecruitment may play a role in pain transition. Motor behavior changed in shoulder pain conditions underlining that motor variability may play a role in the WMSD development as corroborated by the changes in kinematics variability seen with discomfort. This prognostic hypothesis was further, supported by the increased motor variability among workers with high experience.

CONCLUSION

Quantitative assessments of the functional motor adaptations can be a way to benchmark the pain status and help to indentify signs indicating WMSD development. Motor variability is an important characteristic in ergonomic situations. Future studies will investigate the potential benefit of inducing motor variability in occupational settings.

Effectiveness of an ergonomic intervention on work-related posture and low back pain in video display terminal operators: a 3 year cross-over trial

This study investigated the effectiveness of a workstation ergonomic intervention for work-related posture and low back pain (LBP) in Video Display Terminal (VDT) workers. 100 VDT workers were selected to receive the ergonomic intervention, whereas 100 were assigned to a control group. The two groups were then crossed-over after 30 months from baseline. Follow-ups were repeated at 5, 12, and 30 months from baseline and then at 6 months following crossover.

OUTCOMES

Work-related posture and LBP point-prevalence using the Rapid Entire Body Assessment method and a Pain Drawing, respectively. The ergonomic intervention at the workstation improved work-related posture and was effective in reducing LBP point-prevalence both in the first study period and after crossover, and these effects persisted for at least 30 months. In conclusion, our findings contribute to the evidence that individualized ergonomic interventions may be able to improve work-related posture and reduce LBP for VDT workers.

Limited economic evaluation to assess the effectiveness of a university-wide office ergonomics program

The objective of this research was to evaluate the effectiveness and provide a limited economic evaluation of an office ergonomics program at a major university from 1995 to 2007. The relationship between office-related recordable injuries, reported lost time, severity of these injuries, and the Workers' Compensation (WC) paid was analyzed and the corresponding incident cost was calculated. Two major datasets analyzed were OSHA 200/300 logs (1991-2007) and WC claims paid (1999-2007). Since the beginning of the office ergonomics program in 1995 and through 2007 (13-year period), the number of office cumulative trauma disorder (CTD) cases decreased by 53%. Since the official start (in 1999) of a 50-50 cost share agreement for office equipment purchases between the university's Safety and Health Department (SHD) and the university departments evaluated, it was observed that the incident rate decreased by 63%, Total Days Away/restrict or Transfer (DART) rate decreased by 41%, Lost Time Case (LTC) rate decreased by 71% and office-related carpal tunnel syndrome decreased by almost 50%. The long-term goal of this research is to demonstrate the self-sustainability of an office ergonomics program by showing that equipment costs are eventually offset by a decrease in WC claims paid and lost time from office-related injuries and illnesses. While limited, this research helps in cost-justifying the implementation of future office ergonomics programs for large organizations.

Interactive effects from self-reported physical and psychosocial factors in the workplace on neck pain and disability in female office workers

This study explored the interaction between physical and psychosocial factors in the workplace on neck pain and disability in female computer users. A self-report survey was used to collect data on physical risk factors (monitor location, duration of time spent using the keyboard and mouse) and psychosocial domains (as assessed by the Job Content Questionnaire). The neck disability index was the outcome measure. Interactions among the physical and psychosocial factors were examined in analysis of covariance. High supervisor support, decision authority and skill discretion protect against the negative impact of (1) time spent on computer-based tasks, (2) non-optimal placement of the computer monitor and (3) long duration of mouse use. Office workers with greater neck pain experience a combination of high physical and low psychosocial stressors at work. Prevention and intervention strategies that target both sets of risk factors are likely to be more successful than single intervention programmes. STATEMENT OF RELEVANCE: The results of this study demonstrate that the interaction of physical and psychosocial factors in the workplace has a stronger association with neck pain and disability than the presence of either factor alone. This finding has important implications for strategies aimed at the prevention of musculoskeletal problems in office workers.

Evidence-based guidelines for the wise use of computers by children: physical development guidelines

Computer use by children is common and there is concern over the potential impact of this exposure on child physical development. Recently principles for child-specific evidence-based guidelines for wise use of computers have been published and these included one concerning the facilitation of appropriate physical development. This paper reviews the evidence and presents detailed guidelines for this principle. The guidelines include encouraging a mix of sedentary and whole body movement tasks, encouraging reasonable postures during computing tasks through workstation, chair, desk, display and input device selection and adjustment and special issues regarding notebook computer use and carriage, computing skills and responding to discomfort. The evidence limitations highlight opportunities for future research. The guidelines themselves can inform parents and teachers, equipment designers and suppliers and form the basis of content for teaching children the wise use of computers. STATEMENT OF RELEVANCE: Many children use computers and computer-use habits formed in childhood may track into adulthood. Therefore child-computer interaction needs to be carefully managed. These guidelines inform those responsible for children to assist in the wise use of computers.

The effects of walking and cycling computer workstations on keyboard and mouse performance

OBJECTIVE

This study aimed to determine the effects of active workstation designs on speed and error during typing, mouse pointing, and combined type and mouse-use tasks.

BACKGROUND

Office ergonomics has focused on musculoskeletal disorder prevention; however, increasing computer-based work also increases health risks associated with inactivity. Workstations allowing computer users to walk or cycle while performing computer tasks have been shown to demand sufficient energy expenditure to result in significant health benefits. However the performance effects of being active while using a computer have not been documented.

METHOD

Thirty office workers (16 female, 15 touch typists) performed standardized computer tasks in six workstation conditions: sitting, standing, walking at 1.6 km/h and 3.2 km/h, and cycling at 5 and 30 watts. Performance, perceived performance, and heart rate were measured.

RESULTS

Computer task performance was lower when walking and slightly lower when cycling, compared with chair sitting. Standing performance was not different from sitting performance. Mouse performance was more affected than typing performance. Performance decrements were equal for females and males and for touch typists and nontouch typists.

CONCLUSION

Performance decrements maybe related to both biomechanical and cognitive processes. Active workstations may be less suitable for mouse-intensive work and susceptible users.

APPLICATION

Although active workstations may result in some decrement in performance, their ability to increase daily energy expenditure may make them a feasible solution for workplace inactivity.

A randomized controlled trial evaluating an alternative mouse or forearm support on change in median and ulnar nerve motor latency at the wrist

BACKGROUND

The purpose of this study was to determine the effects of an alternative mouse and/or a forearm support board on nerve function at the wrist among engineers.

METHODS

This randomized controlled intervention trial followed 206 engineers for 1 year. Distal motor latency (DML) at baseline and follow-up was conducted for the median and ulnar nerves at the right wrist.

RESULTS

One hundred fifty-four subjects agreed to a nerve conduction study at the beginning and end of the study period. Those who received the alternative mouse had a protective effect (OR = 0.47, 95% CI 0.22-0.98) on change in the right ulnar DML. There was no significant effect on the median nerve DML. The forearm support board had no significant effect on the median or ulnar nerve DML.

CONCLUSIONS

In engineers who use a computer for more than 20 hr per week, an alternative mouse may have a protective effect for ulnar nerve function at the wrist. No protective effect of a forearm support board was found for the median nerve.

Effect of a desk attachment board on posture and muscle activity in women during computer work

Working at a computer is part of a large number of jobs and has been associated with upper extremity musculoskeletal disorders and back pain. The study evaluated the effects of a board attachment on upper extremity and back. The findings are mixed in that the board may have a positive effect in preventing back pain, but may be detrimental to upper extremities. Effect of a desk attachment board on upper extremity and trunk posture, and muscle activity was assessed in women video display terminal users. Participants completed a standard 20-min computer task under two conditions: 1) using a standard desk; 2) using a desk attachment board designed to support the forearms. Bilateral electromyography of the trapezius, multifidus and longissimus muscles and the right anterior deltoid and forearm extensor muscles was recorded. 3-D trunk and upper extremity posture was monitored. Participants were tested before and after 2 weeks of familiarisation with the board in their workplace. Perceived tension and discomfort were recorded before and after use of the board. Use of the board tended to increase muscle activity in the right trapezius and forearm extensor and to decrease muscle activity in the back. Perceived tension in the low back decreased slightly with the board. The board may be useful in reducing tension in the low back during computer work, but may adversely affect the upper extremities.

Aetiology and management of work-related upper extremity disorders

Work-related upper extremity disorders are a major cause for complaints and disability in worker populations. They may consist of a range of symptoms in the upper extremity, either clearly localised or more widespread, and are usually preceded or affected by exposure to physical activities and/or postures at work. In order to develop effective management strategies, both from a prevention and treatment perspective, more knowledge is needed with regard to the nature, pathophysiological mechanisms and risk factors of this group of disorders. This chapter reviews the clinical manifestations, mechanisms and aetiology of work-related upper extremity disorders through an exploration of the literature. We also examine and discuss the evidence for the effectiveness of several preventative and therapeutic interventions.

Workplace interventions to prevent musculoskeletal and visual symptoms and disorders among computer users: a systematic review

BACKGROUND

The literature examining the effects of workstation, eyewear and behavioral interventions on musculoskeletal and visual symptoms among computer users is large and heterogeneous.

METHODS

A systematic review of the literature used a best evidence synthesis approach to address the general question "Do office interventions among computer users have an effect on musculoskeletal or visual health?" This was followed by an evaluation of specific interventions.

RESULTS

The initial search identified 7313 articles which were reduced to 31 studies based on content and quality. Overall, a mixed level of evidence was observed for the general question. Moderate evidence was observed for: (1) no effect of workstation adjustment, (2) no effect of rest breaks and exercise and (3) positive effect of alternative pointing devices. For all other interventions mixed or insufficient evidence of effect was observed.

CONCLUSION

Few high quality studies were found that examined the effects of interventions in the office on musculoskeletal or visual health.

A randomised controlled trial evaluating the effects of two workstation interventions on upper body pain and incident musculoskeletal disorders among computer operators

BACKGROUND

Call centre work with computers is associated with increased rates of upper body pain and musculoskeletal disorders.

METHODS

This one year, randomised controlled intervention trial evaluated the effects of a wide forearm support surface and a trackball on upper body pain severity and incident musculoskeletal disorders among 182 call centre operators at a large healthcare company. Participants were randomised to receive (1) ergonomics training only, (2) training plus a trackball, (3) training plus a forearm support, or (4) training plus a trackball and forearm support. Outcome measures were weekly pain severity scores and diagnosis of incident musculoskeletal disorder in the upper extremities or the neck/shoulder region based on physical examination performed by a physician blinded to intervention. Analyses using Cox proportional hazard models and linear regression models adjusted for demographic factors, baseline pain levels, and psychosocial job factors.

RESULTS

Post-intervention, 63 participants were diagnosed with one or more incident musculoskeletal disorders. Hazard rate ratios showed a protective effect of the armboard for neck/shoulder disorders (HR = 0.49, 95% CI 0.24 to 0.97) after adjusting for baseline pain levels and demographic and psychosocial factors. The armboard also significantly reduced neck/shoulder pain (p = 0.01) and right upper extremity pain (p = 0.002) in comparison to the control group. A return-on-investment model predicted a full return of armboard and installation costs within 10.6 months.

CONCLUSION

Providing a large forearm support combined with ergonomic training is an effective intervention to prevent upper body musculoskeletal disorders and reduce upper body pain associated with computer work among call centre employees.