Is work above the shoulder a high-risk zone?

Waersted and colleagues have published a review in the International Archives of Occupational and Environmental Health to investigate the association between work above shoulder height and shoulder pain/disorders.

Their conclusion - arm elevation with elbows above shoulder level (>90 degrees) shows moderate evidence for an association with shoulder disorders.

Does that make work at < 90 degrees 'safe'?

Putting this data into practice then, can employers then determine a ‘safe level’ of arm elevation by avoiding activity above 90% at the shoulder?

The wonderful thing about research is that it distils down all factors to try to establish specific impact of that factor. In the world of clinical occupational medicine, it is essential to put these findings into context.

We spoke to Occupational and Environmental Physician Registrar, Dr Brett Shannon to understand where this paper adds to our working knowledge of shoulder problems.

“In Occupational Medicine, we look at a range of factors which contribute to a person developing shoulder problems,” explained Dr Shannon,

“Occupational factors such as awkward postures do play a role, but so too do non-work related factors such as age, BMI and the presence of metabolic conditions such as diabetes.”

What is the current evidence?

‍A good starting point is to refer to the AMA Guides to the Evaluation of Disease and Injury Causation (2nd Edition) – as illustrated in Figure 1.

Dr Shannon highlighted the factors where the evidence is strong, stating,

“While the Waersted research adds to the evidence base on the role of awkward postures, it is important for workers and workplaces to also understand the role of non-occupational factors."

Putting this into a real-life scenario, Dr Shannon provided an example of these factors at play,

“If you have a worker who is over 40, and overweight and they perform overhead work then you can expect to see shoulder problems at some point.”

"It is a case of compounding factors."

Which was the responsible: work or non-work factors?

Often a claim will require assessment of whether work was a significant factor in a person’s injury. Shoulder claims are no different.

For the non-doctors in the room, to understand how this gets determined, it helps to first makes sense of what is happening under the skin.

The tendons of the shoulder muscles come under stress from activities that require lifting and rotation of the arm, such as in a throwing type motion. We know that age plays a role as shoulder tears are most commonly found in individuals over 40 years of age. Individuals at a higher risk of sustaining a shoulder injury include those who perform overhead work (e.g.,warehouse workers, laborers, carpenters, painters, construction workers) and certain athletes (e.g., swimmers, tennis players, baseball players.)

Older individuals usually present with a gradual onset of shoulder pain and, ultimately, after radiographic testing are shown to have significant partial or full rotator cuff tears without a clear history of predisposing trauma.

What about COVID?

Whilst COVID-19 impacts on many body systems we do not have data on shoulder injuries related to COVID-19 illness. However, as for many musculoskeletal conditions the impact of biopsychosocial factors on the development of shoulder symptoms is significant.

Dr Shannon explained, “COVID-19 has changed the work practices of many Australian workplaces -as we see changes in roles, job sharing, and change in work environments. Employers need to ensure they continue to monitor employees’ safe systems of work and any impact of physical and social distancing on the ergonomics of manual handling tasks.”

Rates of shoulder claims remain high.

Shoulder work-related injuries across all industry in Australia remain a significant problem.

The trend of serious work-related shoulder claims in Australia has increased by 7% during the period 2000-01 to 2015-16 according to Safe Work Australia data. To put this is in context, the incidence claims for all other bodily locations has gone down, while shoulder claims have gone up.

Implications for workplaces?

Recent evidence continues to highlight that performing work above shoulder height (with elbows above shoulder level) has an association with the development of shoulder disorders. The evidence highlights the importance of:

1.      Ensuring workers are fit to perform the essential and inherent tasks of their role.
         Does your organisation have a process for assessment of fitness - not just
         at the time of employment, but periodically?

2.     Managing symptoms - early.
         Ensure your systems are in place for early triage, treatment and providing suitable
         duties. Telemedicine is an effective method of early diagnosis and management.

3.     Get a good medical advisor to assist you. 

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References

1. Wærsted, M., Koch, M. & Veiersted, K.B. Work above shoulder level and shoulder complaints: a systematic review. Int Arch Occup Environ Health 93, 925–954 (2020). https://doi.org/10.1007/s00420-020-01551-4 https://link.springer.com/article/10.1007/s00420-020-01551-4

2. AMA Guides to the Evaluation of Disease and Injury Causation (2nd Edition)

3. Safe Work Australia, Australian Workers' Compensation Statistics -https://www.safeworkaustralia.gov.au/system/files/documents/2001/australian-workers-compensation-statistics-2017-18_1.pdf