Carpal tunnel syndrome (CTS), also known as median neuritis, is a painful condition of the hands and wrists. It is caused by pressure on the median nerve, which runs from the shoulder down the arm to the hand. In advanced cases, carpal tunnel syndrome can make the simplest chore or activity impossible, such as holding a frying pan, folding laundry, or lifting an infant.
Carpal tunnel syndrome can occur in one wrist, or both (bilateral carpal tunnel). It affects workers in many industries such as meatpacking, grocery checkout, and assembly work. AFSCME members, especially among those who work with computers, are also victims of carpal tunnel syndrome.
Symptoms: In addition to pain, the symptoms of carpal tunnel syndrome include numbness and tingling in the hands. These symptoms are usually felt in the first three fingers and the base of the thumb. Often the pain and other symptoms are worse at night or during sleep.
The figure below shows the parts of the hand and wrist that are involved. Tendons of the fingers, blood vessels, and the median nerve all pass through what is called the carpal tunnel. The carpal tunnel is formed by the carpal ligament in the wrist. Swelling and steady irritation of the tendons that pass through the carpal tunnel create pressure on the median nerve.
Risk factors: The major causes of carpal tunnel syndrome are:
- working with bent wrists;
- a high rate of repetition using the hands;
- a lack of rest for the hands and wrists; and
- forceful hand motions.
All of these risk factors are not necessary to get carpal tunnel syndrome. For example, VDT operators get carpal tunnel syndrome even though modem computers only require a very light force to press the keys. The awkward posture, intense keying, and lack of rest periods are more than enough to cause problems.
Prevention: Carpal tunnel syndrome can be prevented by controlling the risk factors that cause the injury. This is done through the application of ergonomics. Ergonomics means changing the work to fit the worker, rather than making the worker try to fit the work. A comprehensive ergonomics program includes the following elements:
Engineering controls: This means providing equipment to reduce exposure to risk factors. For example, computer operators need to be able to adjust the height of their chair and/or keyboard in order to avoid having to bend their wrists while keying. Other examples include ergonomically designed hand tools that have angled handles that allow workers to keep their wrists straight while using the tools.
Administrative controls: This refers to the pace of work, breaks, other tasks that do not require repetitious hand and wrist movements, and other factors about work organization.
Medical management: The management of CTS requires that a correct diagnosis is made and proper medical treatment and follow-up is provided. Working conditions that expose workers to risk factors need to be eliminated or reduced as much as possible. Without such changes, injured workers will still be exposed to the very conditions that caused the problems in the first place, and will likely cause the workers to be injured again. Having injured workers wear wrist braces and then continue to work under the same conditions that caused their injuries is not acceptable or appropriate medical management.
Early and proper treatment is important for this condition. Treatment should start out conservatively with rest and physical therapy. Surgery should not be the first choice. The person's job may have to be redesigned to remove or reduce risk factors at work. Otherwise, the symptoms are likely to get worse and require surgery to relieve the pain.
Training: Workers and their managers need training about engineering controls, administrative measures, and medical management. Workers should know: how to recognize the signs and symptoms of CTS; who to report them to; how to adjust equipment; when to give their hands and wrists a rest from repetitious and/or forceful motions; and take other steps to prevent getting carpal tunnel syndrome.
Program Evaluation: The ergonomics program needs to be evaluated to find out if the number and severity of cases of carpal tunnel syndrome have been reduced. Accurate and complete records need to be kept in order to measure the effectiveness of the program.
For more information about protecting workers from workplace hazards, contact the AFSCME Health and Safety Program at (202) 429-1228, or 1625 L Street, N.W., Washington, DC 20036.