Home / The problems with assessing the causality of musculoskeletal disorders

There are common issues with the way that musculoskeletal disorders (MSDs) are being assessed in the workplace. EHS professionals need to be aware of these issues and to control for them to ensure effective and accurate workplace injury diagnosis within their organization.

Many musculoskeletal pain and discomfort questionnaires used within workplaces today ask leading questions that can predetermine a “workplace injury” diagnosis. Questions like “is your the pain or discomfort caused or aggravated by your work?” are very common. This type of question seeks to gain an opinion from the individual regarding the causality of their musculoskeletal symptoms but it has obvious limitations with respect to:

  1. The information it collects
  2. The way the information collected is used
  3. The inferences it makes

These limitations are likely to make this question superfluous for a robust, evidence based musculoskeletal symptoms questionnaire.

The problems with self-reporting of symptom causality

Asking people if their symptoms are caused or aggravated by work tends to result in a subjective response based on beliefs that are not necessarily correct. There is no way of knowing if the worker’s attribution of causality is accurate.

Workers may be genuinely mistaken in ascribing the cause of their problem to their work, when there is no such link. Furthermore, they may fail to recognize a link with working conditions when there is one.

A previous study that considered the potential for error in attributing arm pain to work (Palmer et al, 2008) found that self-reports of work-relatedness were substantially higher than the actual relative risk estimated from arm-straining activity.

Key point: Self reporting of workplace injury causation is very likely to be inaccurate

The problems with use of information on symptom causality

When the question of causality is asked it immediately raises a second question; what is the information going to be used for? The answer to the second question will affect the response given to the first question.

Is the diagnosis of an injury as ‘work related’ going to change the way a person’s discomfort is managed? Is discomfort not attributed to work going to be ignored or given a lesser status?

The evidence in the literature shows overwhelmingly that musculoskeletal discomfort is multi-factorial with risks factors including posture, repetition, environment, psychosocial and individual factors. All aspects need to be recognized within the workplace if a prevention and management program is to be successful.

In addition, there is strong evidence that musculoskeletal pain can reduce productivity both through sickness absence and reduced performance. If a person is experiencing discomfort, whatever the cause, it needs to be managed at work as well as considering all potential contributing factors including factors outside work, so that effects on productivity can be minimized and recovery maximized.

Burton et al (2008), in a Health and Safety Executive report in the United Kingdom, encouraged concentration on the concept of ‘work-relevant’ symptoms and not a focus on causation:

“It seems more reasonable to refer to ULDs [upper limb disorders] among workers as work-relevant, which avoids undue concentration on occupational causation yet allows recognition that work can be troublesome for people experiencing upper limb symptoms, irrespective of their cause. Regardless of the causation debate, the consistent association between upper limb complaints and the physical demands of work shows that ULDs are frequently work-relevant….Recognition of this issue is likely to be an important aspect for successful interventions.”

Reviews of interventions that aimed to improve musculoskeletal health in the workplace have concluded the most successful programs include multiple interventions that are based on the identified risk factors for individuals. Recognizing that musculoskeletal problems have multi-factorial origins is important so that solutions for problems are found through multiple interventions. If this is not done then important solutions for managing the problem may be overlooked.

To illustrate this, Waugh et al (2004) reported on a study in which they aimed to identify the key factors associated with the outcomes of conservatively managed lateral epicondylalgia (‘tennis elbow’). Whilst many subjects attributed their injury to sports the key factor associated with functional problems and pain scale scores was repetitive work activities. The authors concluded that:

“Although many of the participants identified sports activities as the cause of their injury, these findings emphasize the importance that a patient’s work tasks can have on recovery of lateral epicondylalgia. This would suggest that management should perhaps focus on work stations, postures, and behaviors.”

Similarly, poor outcomes could result if non-work factors are not considered when trying to manage a work discomfort problem.

Key point: The cause of the problem is not as important as how the problem may affect someone’s work performance. All factors both work and non-work must be considered to minimize the effect of discomfort on work performance. 

The problems with causality questions

The question ‘Is your the pain or discomfort caused or aggravated by your work?’ leads the respondent to consider only a work cause for their discomfort which may again result in false or biased information. This also may lead employees to consider making a claim for compensation for personal injury even if that injury is not truly work related.

Evaluation of workers’ compensation claims for occupational injuries are generally based on medical expertise supported by scientific studies linking the particular disorder to the nature of the workers’ task. This process, regardless of the final outcome, can be costly for the organization and can be stressful for the person who lodges the claim as their general health and daily activities are scrutinized. Workers’ compensation experiences can also be unsatisfactory for claimants and be a barrier to successful rehabilitation.

A person’s belief about their musculoskeletal problem has a large impact on their recovery and functional status. In particular, patients’ perceptions and beliefs about work and returning to work may be a significant hindrance for actual recovery. If someone believes that their work is ‘dangerous’ and performing their work activities will increase their pain they are less likely to recover and return to work. Dispelling these beliefs and not enhancing them in any way, in particular the formation of assessments, is an important part of managing musculoskeletal disorders in the workplace.

Key point: Leading questions regarding causality may increase compensation processes and enhance individuals’ beliefs that work is detrimental to their health. These can be major barriers to recovery.