Ergonomic adjustments do not help to alleviate work-related discomfort once it has already arisen

The study makes a significant contribution to our understanding of the effectiveness of ergonomic interventions for workers with musculoskeletal disorders of the arm, neck or shoulder. The review’s methodology is rigorous and systematically assesses the quality and certainty of the available evidence. Its findings do not show clear short-term benefits from the ergonomic interventions studied in alleviating existing musculoskeletal discomfort, which provides valuable information for guiding action strategies. Furthermore, the review also finds that ergonomic interventions are likely to produce a small reduction in pain in the long term, with evidence of moderate certainty.

However, it is important to interpret the scope of the research and its conclusions correctly. It should be borne in mind that the fundamental role of occupational ergonomics is to intervene before work-related health problems arise, by identifying, assessing and reducing risk factors, rather than attempting to correct their consequences once they have manifested. In other words, the primary objective of occupational ergonomics is preventative, rather than therapeutic or reactive. This review, by contrast, analyses the effectiveness of specific ergonomic interventions as a treatment for workers who already suffer from these conditions. These are two distinct objectives, and findings relating to one cannot be directly extrapolated to the other. Therefore, this study does not provide evidence that calls into question the preventive role of occupational ergonomics; rather, it highlights the limitations of the available evidence regarding its use as a treatment. It would be a mistake to interpret these results as an argument for reducing preventive ergonomic measures in the workplace.

Whilst the review is valuable, it has some limitations that must be taken into account. The authors acknowledge that all the included trials present a high overall risk of bias, as well as heterogeneity in the interventions analysed and a predominance of studies involving office workers. This limits the possibility of generalising the results to other work environments. Furthermore, the term ‘ergonomic intervention’ encompasses a wide range of very different measures, from simple postural recommendations or training to modifications to equipment; the review does not allow for a systematic assessment of the extent to which these measures succeeded in reducing exposure to biomechanical risk factors. Therefore, interpreting its conclusions as a general demonstration of the ineffectiveness of ergonomic interventions would go beyond what the data allow us to conclude.

The article addresses a problem of vital importance in the field of occupational health: musculoskeletal disorders amongst workers. These rank amongst the leading causes of sick leave due to general and work-related illnesses and are the leading cause of reported occupational diseases.

The manuscript reviews the literature on ergonomic interventions carried out to improve symptoms and quality of life among affected workers, concluding that in most cases these interventions prove to be of limited effectiveness once the condition or discomfort has already developed, which should lead us to focus on prevention rather than on the treatment of these conditions.

The literature review carried out complies with internationally accepted protocols for this type of study and includes a sufficiently large number of studies with adequate representation of workers from different parts of the world, comprising 20 studies with a total of 2,478 participants. The results—albeit with the caution that must always be exercised when analysing this type of research due to potential biases (which the authors themselves acknowledge in the manuscript, detailing how they sought to minimise them)—are conclusive and may open up new avenues of research. It is even noted that the evidence regarding certain practices is uncertain and that further studies in this field are required.

This research comprises a Cochrane review that updates previous work by analysing 20 studies involving a total of 2,478 participants with work-related arm, neck or shoulder complaints, known as CANS (Complaints of Arm, Neck and/or Shoulder). Of these 20 studies, 13 involved office workers or computer users, and seven involved factory workers, sewing machine operators and slaughterhouse workers.

The authors conclude that the current evidence does not sufficiently support the use of ergonomic interventions as a stand-alone treatment to reduce pain, improve functionality or facilitate short-term recovery in people with CANS. Furthermore, the authors consider that ergonomic strategies could be useful in specific subgroups or as part of a broader rehabilitation or workplace intervention programme.

The authors therefore indicate that well-designed, high-quality clinical trials are required to determine the role of ergonomic interventions in managing WMSDs. They highlight significant limitations in their findings, noting the low quality and methodological shortcomings of the studies analysed.

Other significant limitations include: the small number of available studies (in the context of this research); the small number of participants in these studies; the variability of results across different studies; the fact that participants knew which intervention they received (the authors highlight significant risks of bias); and the predominance of office-based roles.

It is important to note that the conclusions and limitations of this review must be confined to the interventions studied. In any case, in addition to these limitations, it is necessary to consider other aspects that could influence the interpretation of this research.

Firstly, ergonomic interventions in workplaces of this nature are subject, in Spain, to the legal framework established by Law 31/1995 on the Prevention of Occupational Risks.

Secondly, it is important to distinguish between the objectives of an ergonomic intervention: those aimed at preventing the onset of discomfort or disorders, those aimed at preventing their worsening, and those aimed at treating existing symptoms and limitations.

Thirdly, ergonomic interventions are highly diverse and can affect the entire workstation throughout its life cycle. Thus, the scope of these interventions extends beyond musculoskeletal disorders and may encompass other dimensions of the interaction between the individual, the task and the environment (the work system). Fourthly, the organisational and psychosocial context can influence both the progression of musculoskeletal discomfort and the implementation and outcomes of the interventions.

Finally, as a general comment on the above, this research is relevant because it helps to define the current evidence regarding the potential benefits of ergonomic interventions for reducing pain, improving functionality or facilitating short-term recovery in people with CANS.

Furthermore, it is particularly important to emphasise that the findings of this research do not allow us to conclude that ergonomic interventions in the context of CANS are ineffective in reducing exposure or preventing harm.