What Causes Carpal Tunnel?

A common factor in developing carpal tunnel symptoms is increased hand use or activity.

While repetitive activities are often blamed, the correlation is often unclear. Physiology and family history may have a significant role in individual's susceptibility.

Many cases of carpal tunnel syndrome are provoked by repetitive grasping and manipulating activities. The exposure can be cumulative. Activities may be work-related or related to other activities (i.e. home improvement chores.)

Symptoms are commonly exacerbated by forceful and repetitive use of the hand and wrists in industrial occupations, including jack hammer operators, meat packers, computer users and musicians. The condition has been documented for decades, but in recent 10 to 20 years has become more prevalent, probably due to better public awareness and earlier diagnosis.

There are a number of causes of carpal tunnel syndrome. They can be either traumatic, or non-traumatic.

Work related exposure is a common contributor. In the U.S., for instance, carpal tunnel syndrome is the biggest single contributing factor to lost time at work. This syndrome results in billions of dollars of workers compensation claims every year.

However, recent studies and peer review articles have found no relationship between carpal tunnel syndrome and office-type work. Specifically, research studies have found no statistically significant association between Carpal Tunnel and keyboard use. The jury is still out on what, if any, relationship may exist between this condition and light office work or computer use.

Recently the Harvard Medical School published a report in which it addressed carpal tunnel syndrome. The Harvard report cited to the 2003 Journal of American Medical Association study and the 2001 study in Neurology that computer use did not increase a person's risk of development. Several studies have indicated a strong correlation between an employees general physical condition and carpal tunnel complaints.

Hyperthyroidism, osteoarthritis and diabetes were most often associated with Carpal Tunnel symptoms, as were variables such as age, obesity and wrist dimension. In a studies by SG Atcheson, only 35 of 297 subjects were aware of the underlying health condition which could account for their symptoms. Hence, these causes would be missed by doctors if they were relying on a patient's health history to rule out other causative factors. It is important that a doctor rule out other causes as well. If a patient does not have Carpal Tunnel, corrective surgery is destined to fail.

It's not all in your head. Studies have also related this syndrome and other upper extremity complaints with psychological and social factors. A large amount of psychological distress showed doubled risk of the report pain, while job demands, poor support from colleagues, and work dissatisfaction also showed an increase in the report of pain, even after short term exposure.

On the other hand, in 1997, studies done by the National Institute for Occupational Safety and Health (NIOSH), indicated that job tasks involving highly repetitive manual acts or necessitating wrist bending or other stressful wrist postures were connected. However, it appears that the 30+ studies reviewed were concerned with the occupations of assembly line workers, meat packers, food processors, and the like, not general office work.

The medical and scientific studies are consistent in finding no statistically significant relationship between upper extremity repetitive trauma claims and the workplace.

In summary, the underlying cause of carpal tunnel syndrome is still in question . People that develop symptoms will frequently blame this on their work exposure, even though this exposure may indeed have little to do with the root cause of this syndrome.