Background
Work-related complaints of the arm, neck or shoulder are also called repetitive strain injury or occupational overuse syndrome. They are a burden for individual workers, for their employers and for society at large because they impair functioning both in daily life and at work.
Studies included in the review
We included randomised controlled studies of all possible treatments such as exercises, ergonomic adjustments at the workplace, massage and manual therapy. These treatments aim to reduce pain and improve functioning, and they can be provided by general practitioners or physiotherapists. We excluded injections and surgical procedures that invade the body and require more special skills. We included studies only if the authors wrote that the people they studied had complaints that were work-related. We searched electronic databases up until May 2013.
Findings
We found 44 studies that included 6,580 persons. Twenty-one studies evaluated exercises, 13 evaluated ergonomic workplace adjustments and nine behavioural interventions. We combined the results of these studies per category. Eight other studies evaluated various other treatments.
We did not find a consistent effect of any treatment on pain, recovery, disability or sick leave. Ergonomic interventions reduced pain in the long term but not in the short term in several studies. We judged nine studies to be of high quality, but the results were very inconsistent. We found no reason for the variation in study results. Better studies are needed that are bigger, have a clearer diagnosis of work-relatedness and comply with reporting guidelines.
We found very low-quality evidence indicating that pain, recovery, disability and sick leave are similar after exercises when compared with no treatment, with minor intervention controls or with exercises provided as additional treatment to people with work-related complaints of the arm, neck or shoulder. Low-quality evidence also showed that ergonomic interventions did not decrease pain at short-term follow-up but did decrease pain at long-term follow-up. There was no evidence of an effect on other outcomes. For behavioural and other interventions, there was no evidence of a consistent effect on any of the outcomes.
Studies are needed that include more participants, that are clear about the diagnosis of work-relatedness and that report findings according to current guidelines.
Work-related upper limb disorder (WRULD), repetitive strain injury (RSI), occupational overuse syndrome (OOS) and work-related complaints of the arm, neck or shoulder (CANS) are the most frequently used umbrella terms for disorders that develop as a result of repetitive movements, awkward postures and impact of external forces such as those associated with operating vibrating tools. Work-related CANS, which is the term we use in this review, severely hampers the working population.
To assess the effects of conservative interventions for work-related complaints of the arm, neck or shoulder (CANS) in adults on pain, function and work-related outcomes.
We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, 31 May 2013), MEDLINE (1950 to 31 May 2013), EMBASE (1988 to 31 May 2013), CINAHL (1982 to 31 May 2013), AMED (1985 to 31 May 2013), PsycINFO (1806 to 31 May 2013), the Physiotherapy Evidence Database (PEDro; inception to 31 May 2013) and the Occupational Therapy Systematic Evaluation of Evidence Database (OTseeker; inception to 31 May 2013). We did not apply any language restrictions.
We included randomised controlled trials (RCTs) and quasi-randomised controlled trials evaluating conservative interventions for work-related complaints of the arm, neck or shoulder in adults. We excluded trials undertaken to test injections and surgery. We included studies that evaluated effects on pain, functional status or work ability.
Two review authors independently selected trials for inclusion, extracted data and assessed risk of bias of the included studies. When studies were sufficiently similar, we performed statistical pooling of reported results.
We included 44 studies (62 publications) with 6,580 participants that evaluated 25 different interventions. We categorised these interventions according to their working mechanisms into exercises, ergonomics, behavioural and other interventions.
Overall, we judged 35 studies as having a high risk of bias mainly because of an unknown randomisation procedure, lack of a concealed allocation procedure, unblinded trial participants or lack of an intention-to-treat analysis.
We found very low-quality evidence showing that exercises did not improve pain in comparison with no treatment (five studies, standardised mean difference (SMD) -0.52, 95% confidence interval (CI) -1.08 to 0.03), or minor intervention controls (three studies, SMD -0.25, 95% CI -0.87 to 0.37) or when provided as additional treatment (two studies, inconsistent results) at short-term follow-up or at long-term follow-up. Results were similar for recovery, disability and sick leave. Specific exercises led to increased pain at short-term follow-up when compared with general exercises (four studies, SMD 0.45, 95% CI 0.14 to 0.75)
We found very low-quality evidence indicating that ergonomic interventions did not lead to a decrease in pain when compared with no intervention at short-term follow-up (three studies, SMD -0.07, 95% CI -0.36 to 0.22) but did decrease pain at long-term follow-up (four studies, SMD -0.76, 95% CI -1.35 to -0.16). There was no effect on disability but sick leave decreased in two studies (risk ratio (RR) 0.48, 95% CI 0.32 to 0.76). None of the ergonomic interventions was more beneficial for any outcome measures when compared with another treatment or with no treatment or with placebo.
Behavioural interventions had inconsistent effects on pain and disability, with some subgroups showing benefit and others showing no significant improvement when compared with no treatment, minor intervention controls or other behavioural interventions.
In the eight studies that evaluated various other interventions, there was no evidence of a clear beneficial effect of any of the interventions provided.