Having a job or hobby that involves repetitive hand motions may increase the risk for carpal tunnel syndrome, but a few simple measures can greatly lower the risk.
The work environment is as crucial as the number of hours spent on a task. An adjustable chair and keyboard and a wrist rest can alleviate stress.
Even though it's reserved for more severe cases, carpal tunnel release is one of the more commonly performed surgeries in the United States.
Getting A Grip on Carpal Tunnel
What do a computer keyboarder, poultry processor and air hammer operator all have in common? It may sound like the beginning of a bad joke, but the answer is no laughing matter. All three occupations put workers at risk for carpal tunnel syndrome, a painful and debilitating hand injury caused by repetitive stress.
The carpal tunnel lies at the base of the palm. The floor and walls of the tunnel are formed by the carpal bones of the wrist, and the carpal ligament forms the roof. The median nerve and nine flexor tendons pass through the tunnel. The median nerve, which runs from the neck to the fingertips, governs thumb strength and feeling in the thumb, index, middle and part of the ring finger. If overuse or injury cause swelling of the tissues in the carpal tunnel, the median nerve becomes compressed leading to pain and weakness in the fingers.
Persons with carpal tunnel syndrome typically complain of numbness, a stinging, prickly pain or tingling sensations in the thumb and first three fingers. For many persons symptoms occur at night or when doing everyday activities such as reading or driving. The pain can also travel up the median nerve, shooting from the hand to the shoulder.
The expansion of computer technology for both work and leisure has dramatically increased the number of hours Americans of all ages and professions spend at the keyboard. Typing and operating a mouse or the controls of computer games can all lead to repetitive stress injuries. Other workers at risk are those in meat, fish and poultry processing where repeated cutting and tearing actions may be used; construction workers; electronics assemblers, and supermarket cashiers and scanners. Workers who use power tools with a trigger or who work repeatedly with tools that vibrate, such as jack hammers and air hammers, are also at risk.
If the world of work is beginning to sound a little high risk, recreational activities can also pose a hazard. Knitting, sewing, tennis, playing the piano, woodworking and numerous other activities that are performed frequently and involve a significant amount of time can lead to a repetitive use injury to the hands.
Avoiding Problems
Having a job or hobby that involves repetitive hand motions may increase the risk for carpal tunnel syndrome, but a few simple steps can greatly lower the risk.
- Stretch and flex hands and arms before beginning a task. Take frequent breaks and stretch again in the breaks.
- Alternate activities as much as possible. Employers may need to evaluate work assignments and train workers to perform a number of different tasks rather than the one task repeatedly.
- Analyze daily activities to see where repetitive stress occurs and modify hobbies and tasks as much as possible to minimize stress. Focus on hand-intensive tasks that involve high levels of force, repetition and vibration.
The work environment can be just as crucial as the number of hours spent on a task. For computer keyboarders an adjustable chair and keyboard and a wrist rest can alleviate stress.
Diagnosis and Treatment
A physical exam and medical history are the first steps in diagnosing carpal tunnel syndrome. If carpal tunnel syndrome is suspected, nerve conduction and electromyelographic studies are ordered to detect abnormalities. X-rays are sometimes used to help rule out arthritis.
A Swedish population study found that although 14 percent of people complain of pain, numbness and tingling in the hands, only 3 percent actually have carpal tunnel syndrome. Arthritis, tendonitis and many other conditions can cause similar symptoms.
Once carpal tunnel syndrome is diagnosed, a number of treatment options are available. Physicians usually begin with the most conservative options and suggest more drastic treatments such as surgery only when other approaches have failed.
The first step in treatment is to follow the preventive steps: rest, alternating activities, stretching and modifying the work environment.
A splint or brace worn on the hand can be helpful. Studies show that using a properly fitted wrist splint, especially within three months of the beginning of symptoms, significantly improves the function of the median nerve on standard nerve conduction tests. Neutral angle splints are usually recommended.
Nonsteroidal antiinflammatory drugs (NSAIDs) are often prescribed to treat the pain and to reduce swelling and inflammation.
Steroids injected into the affected area of the wrist can be effective over the short term, but they do not affect a cure, and repeated injections are not recommended.
A recent study published in the Journal of the American Medical Association reported that yoga may be a way to avoid drugs, wrist splints, surgery or a change of job for many patients.
A study compared two groups of patients diagnosed with carpal tunnel syndrome. One group attended two hour-long lyengar yoga sessions per week for eight weeks to learn stretching techniques. At the end of the eight weeks the yoga group experienced less than half the pain of the control group and had increased their grip strength fourfold.
Researchers believe that yoga may be beneficial because it promotes flexibility and strength and teaches better joint posture which may relieve compression in the carpal tunnel.
Despite the fact that surgery is reserved for more serious cases of carpal tunnel syndrome, carpal tunnel release is one of the more commonly performed surgeries in the United States. Although the surgery tends to have high success rates it can cost tens of thousands of dollars when surgical fees, rehabilitation costs and time lost from work are factored in.
The goal of surgical treatment is to relieve compression on the median nerve and to prevent progressive nerve damage. Most patients regain the grip strength they had prior to surgery after three to six months.
Carpal tunnel syndrome is a common complaint, affecting an estimated 10 percent of the population at some time in life. Awareness of the kinds of repetitive stress that cause symptoms, stretching fingers and hands, taking frequent breaks from tasks that put stress on hands and having ergonomically designed tools and work stations can help keep hands and fingers healthy and pain-free.
References
Isam Atroshi et al, "Prevalence of Carpal Tunnel Syndrome in a General Population," JAMA, July 14, 1999.
Patricia Fernberg, "Is It Carpal Tunnel Syndrome?" Occupational Hazards, June 1998.
M.S. Garfinkel et al, "Yoga-Based Intervention for Carpal Tunnel Syndrome: A Randomized Trial," JAMA, November 11, 1998.
Amy Helwig, "Treating Carpal Tunnel Syndrome," Journal of Family Practice, January 2000.
Mi Young Hwang, "Detecting Carpal Tunnel Syndrome," JAMA, July 14, 1999.
Ghazi Rayan, "Understanding and Managing Carpal Tunnel Syndrome," The Journal of Musculoskeletal Medicine, November 1999.
Robert Schwendimann, "Understanding Common Compression Neuropathies," Internal Medicine, October 1999.
Nancy Talbott, "Prevalence of Carpal Tunnel Syndrome in a General Population," Physical Therapy, December 1999.
David Yocum, "The Many Faces of Carpal Tunnel Syndrome," Archives of Internal Medicine, July 27, 1998.
Peter C. Janes, MD is President of the Summit Hockey Association and a provider for Vail • Summit Orthopaedics in Frisco, Edwards, and Vail, Colorado.
