Carpal Tunnel Syndrome is a frequent pathology affecting individuals over 35 years of age and mostly women. It is often thought to be caused by manual labour and computer work. Currently, the aetiology of this condition remains controversial and it is unclear to what extent anatomical and predisposing factors or professional activities lead to the disease.
Different from an acute injury, a Carpal Tunnel Syndrome is the result of a slow degenerative process either linked to metabolic changes and fibrotic growth of the synovium or arising from prolonged, excessive/repetitive wrist flexion-extension and grip movement typical of some professions.
A review article published in 2016 in the journal Best Practice & Research: Clinical Rheumatology,
analysing the literature around the relationship of Carpal Tunnel Syndrome with occupational activities, highlights the lack of evidence for the association between the disease and computer-mouse work and reinforces the link with wrist flexion/extension movement and forceful gripping, especially when both activities are combined.
Assessing compensation claims for Carpal Tunnel Syndrome: The examiner dilemma
The compensation cost for Carpal Tunnel Syndrome is substantial. In the US, the National Council on Compensation Insurance
(NCCI) states that compensation for Carpal Tunnel Syndrome is second only to compensation for disc pathology of the lumbar spine in terms of lost-time claims. In fact, $1 out of $3 given for worker compensation was due to Carpal Tunnel Syndrome.
The lack of clarity on the causation of Carpal Tunnel Syndrome poses a challenge for a medical examiner who attempts to distinguish between work and constitutional factors, especially when work compensation is at stake. Furthermore, the examiner may be required to state whether the occupational practice may have exacerbated an existing condition.
The New South Wales Workers Compensation Act provides a set of useful criteria
to determine whether occupational factors contribute to an injury, which help differentiate an injury from a degenerative disease.
- Time & place of injury
- Work nature & tasks performed
- Employment duration
- Probability of the injury to occur in worker’s life independent of profession
- Worker’s health prior to disease
- Worker’s life-style/activities outside workplace.
The Act also requires the examiner to express judgement as to whether specific occupational practices pose a higher risk to cause the disease, and thus demonstrate that the employment has indeed contributed to its development. However, there is never an absolute certainty on the causality and each client case needs to be examined individually.