WHEN IS CARPAL TUNNEL SYNDROME WORK RELATED? IT DEPENDS…
Carpal Tunnel Syndrome (“CTS”) injuries – and other repetitive-motion conditions are common for employers to see in the workers’ compensation arena, and they can be considered occupational diseases under the West Virginia Workers’ Compensation Act, as well. But since these types of conditions can often be the result of activities outside of the workplace, how does an employer know when one is actually related to the job?
CTS – a compression of the median nerve at the wrist – is characterized by numbness and paresthesia (a burning or tingling) of the thumb, index finger, long finger, and occasionally the entire hand. The main complaints with CTS include nocturnal numbness, clumsiness, and a loss of fine dexterity. Several predisposing factors for CTS aren’t work-related, however, including diabetes, pregnancy, arthritis, thyroid dysfunction, and other metabolic conditions. In fact, repetitive-motion injuries may occur from repeated physical movements which cause damage to tendons, nerves, muscles, and other soft body tissue. These injuries are frequently identified as cumulative trauma disorders (CTDs) and may result in various conditions in addition to CTS, including tendinitis, thoracic outlet syndrome, epicondylitis, and even lower back strains.
What makes things really confusing for employers, though, is the complete group of labels that are bandied about to describe the conditions, which vary from painful soft-tissue syndromes that have no sequel to rare conditions such as entrapment neuropathies. Some medical literature indicates that CTS, for example, should be quite rare based on epidemiology studies. Clearly, a true forceful impact on the median nerve at the wrist can produce CTS acutely, or it can result with the passage of time. It’s also true that some individuals have idiopathic CTS (i.e., of no known origin), and unfortunately, there has long been a societal incentive to shift idiopathic carpal tunnel syndrome to the workers’ comp system.
Employers need not completely despair, however. Breaking free from the prevailing attitude toward the almost automatic compensability of carpal tunnel syndrome claims, Rule 20 of the Code of State Regulations in West Virginia was recently implemented. Rule 20 was promulgated by the Workers’ Compensation Board of Managers to establish a process for the medical management of claim and awards of disability. Rule 20 recognizes that several predisposing factors – not just work – can contribute to the development of carpal tunnel syndrome, including diabetes, hypothyroidism, obesity, alcohol use, rheumatoid arthritis, postural abnormalities, and pregnancy. It also recognizes that:
- Nerve conduction studies are the standard diagnostic modality for confirming the syndrome’s presence.
- Certain occupational groups are at a higher risk for developing carpal tunnel syndrome, including grinders, butchers, grocery store workers, frozen-food factory workers, manufacturing workers, dental hygienists, and platers.
- Awkward wrist positioning, vibratory tools, significant grip force, and the high force of repetitive manual movements can contribute to the development of carpal tunnel syndrome.
- Work-related carpal tunnel syndrome is associated with years of repetitive activity, so to find the condition in workers with weeks to months of activity suggests a pre-existing condition.
- Finally and most importantly, medical studies have failed to show a relationship between normal clerical activities and the syndrome.
These guidelines are important for employers because they are a welcome break from the ‘repetition’ that was the way CTS injuries were usually treated in West Virginia. Unlike in the past, it’s no longer enough for a claimant to simply show that a doctor has diagnosed him or her with CTS and to simply indicate the syndrome is related to work duties.
Instead, claimants now more appropriately have the burden to show that their CTS is work-related, using both medical and factual evidence.