Changing attitudes within WCB are seeing more carpal tunnel claims denied.

A reader wrote recently about WCB’s refusal to compensate her carpal tunnel syndrome (CTS). She believes that decades spent in a clerical role contributed to debilitating bilateral wrist pain. She is anxious and wonders whether the Board’s decision is appealable.


Unfortunately for her, WCB’s attitude towards carpal tunnel causation has changed in recent years. The same could also be said of the Board’s evolving stance on spinal stenosis, a similar condition whereby pain, numbness and weakness are caused by a narrowing nerve canal. For years the general consensus was that work factors such as exposure to vibrating tools or repetitive flexing of the wrist while keyboarding generated harmful pressure on the median nerve. However, the latest scientific evidence is conflicting and these factors haven’t been established as direct causes of CTS.


Several recent studies have investigated causation between computer use and carpal tunnel syndrome. Evidence suggests that mouse usage, and not the use of a keyboard, may be the key problem. And while these studies did not conclusively prove that carpal tunnel is triggered by typing or using a mouse, these activities can cause tendinitis or bursitis in the hand, both of which are known to narrow the carpal tunnel and lead to symptoms.

Worth appealing?

Well then, is the reader’s claim appealable? Probably, yes. First off, the reader will need to show that her normal work duties made her susceptible to CTS. CTS is commonly associated with factory workers, data entry clerks or typists, and others who frequently rely on computers. As such, because there is strong correlation between her occupation and higher rates of CTS, she’s more likely to be successful on appeal.

As for anatomic factors that could negate coverage, it is true that pre-existing fractures, dislocations or even arthritis can deform small bones in the wrist and thus alter the space within the carpal tunnel. Moreover, people who have smaller carpal tunnels by nature are more likely to develop CTS. Nerve-damaging conditions and chronic illnesses such as diabetes also place the median nerve at greater risk of dysfunction. And yet, even if the reader shows a history of previous wrist trauma and, say, suffers from diabetes, the decision may still be overturned on the grounds of work-related causation or aggravation.

How WCB handles pre-existing injuries

But doesn’t WCB deny coverage related to pre-existing injuries? To the contrary, the Board is mandated to take claimants ‘as they are.’ That is, even if anatomical abnormalities and comorbidities place the reader at greater risk of developing CTS, her susceptibility should not negate coverage. To secure benefits in these instances, the but-for rule applies i.e., but-for work exposures, would an injury or illness have occurred. Where a work-related factor, however tangential, contributes to either causation or aggravation, the claim is acceptable. Compensation doesn’t require that work exposures be the leading cause of injury or disease, but rather, that work factors merely play some role in causing or aggravating a disability, however minor.

The bottom line


The reader is strongly advised to seek the services of an experienced WCB consultant to undertake an appeal. Although the initial claim decision didn’t go as hoped, its distinctly possible that the adjudicator who denied the claim didn’t fully understand the context. For this very reason, a qualified WCB consultant ensures that the unique circumstances of a claimant’s work history are fully unpacked and expressed to the Board. This advocacy ensures that a worker gets a fair shake.

From its office in Edmonton, and soon-to-be new office in Calgary, Blue Collar Consulting serves all corners of Alberta. Contact us today for more information regarding all your WCB questions.