Carpel tunnel syndrome, a hand and wrist disorder that may bring debilitating pain and weakness of the thumb and fingers, is the most common of all injuries that result from jobs requiring repetitive motions. The incidence of repetitive motion injuries has escalated in the last two decades – from 18 percent of all workplace maladies in 1981 to 48 percent in 1988, according to a U.S. Department of Labor study.

Any job that requires vigorous use of the hands in the same way for prolonged periods of time can cause CTS. Among those at risk are mail sorters, gardeners, supermarket checkout clerks, hairdressers, autoworkers and musicians – and, among musicians, especially pianists, violinists, bassists and drummers. Computers are a prime cause of repetitive strain injuries and their use can increase the risk for musicians, many of whom compose and handle their business affairs on the computer.

The carpal tunnel is a rigid space that runs through the wrist, and contains the median nerve and eight flexor tendons. Repetitive motion can cause the sheaths of these tendons to become irritated and swollen, putting pressure on the nerve.

Workers’ compensation cases for carpal tunnel syndrome are complicated by the fact that repetitive motion is not the only cause. It can be triggered by a host of disorders – like thyroid problems, rheumatoid arthritis, gout, diabetes, a blow to the wrist or a sprain – that cause an increase of swelling in the tunnel or a decrease of circulation in the median nerve.

The symptoms can vary, but generally the chief one is numbness (some describe it as tingling or burning) usually over the thumb, index finger, long finger and half of the ring finger. Some feel discomfort radiating upward from the wrist to their shoulders. Symptoms frequently are experienced in the middle of the night. And performing the “triggering” activity will often cause a flare-up to occur.

The pins-and-needles sensation can be very uncomfortable. Your hand may feel weak and dexterity may be reduced, making it harder to play an instrument or write. CTS can also be very dangerous. Of all your pressure-sensitive nerve endings, 25 percent are in your fingertips. If you can’t feel what you’re touching – for instance, hot objects – that’s serious.

One electric bassist finds that his hands completely freeze up during long repetitive passages involving continuous thumping on the bass string on a single note, typical in “funk” and “hot country” music. This can make it impossible or very difficult to work as a musician.

One remedy for CTS is surgery, but that is not a step to be taken lightly. In the surgery, the transverse carpal ligament is divided to relieve pressure on the median nerve. In some cases the swollen tendon sheaths are removed. Depending on the type of work they do, some patients can return to work in three to six weeks. Not every patient with symptoms of CTS should have an operation, but if there is a nerve conduction problem in the wrist, many patients can improve from surgery even after returning to work.

Carpal tunnel surgery should be done only by a surgeon who specializes in hand surgery. Many surgeons have jumped on the bandwagon since the disease has become widespread, but not all of them are qualified to treat CTS.

There are other preventive measures. Occupational therapists suggest avoiding use of the wrist in a bent or twisted position for long periods, and using the whole hand, not just the thumb and forefinger, to grasp objects. For those who work at a computer, palms should be kept up off the keyboard. Ergonomics (adapting the workplace to the worker) can help and many occupational therapist have expertise in this area. Some musicians can benefit from being trained how to sit correctly, or from adjusting the height of instruments like the bass or drums (particularly the snare drum or the drummer’s seat).

For more information, a particularly useful resource is “The Repetitive Strain Injury Sourcebook,” by Sandra Peddie and Craig Rosenberg, M.D., Lowell House, 1997.