UFCW | Repetitive Stress Injuries Overview

In many areas of your workplace, workers are at jobs requiring repetitive bending and twisting of the hand and wrist. There are hundreds of jobs that involve these kind of hand movements. These repetitive tasks often place excessive stress on muscles and nerves in the hand and wrist and cause a musculoskeletal disorder--a painful and often crippling disease--tendinitis, ganglion cysts, and tenosynovitis. These are all serious hand and wrist disorders that are showing up in dramatic numbers among workers in all industries.

Tendinitis
Caused when the tendons in the hand and wrist become inflamed from repeated stressful movements of the wrist, such as from folding boxes. Sometimes the fibers that make up the tendon can actually tear. If this condition is left untreated, the tendon may be permanently weakened.

Tensoynovitis
Caused when the sheath--or casing--around the tendon becomes inflamed because of overuse. This inflamed sheath can fill up with fluid, causing severe pain. Sometimes this swollen sheath causes a bump under the skin, often on the wrist, called a ganglion cyst.

Carpal Tunnel syndrome
This painful and potentially crippling disease is caused by repeated bending and twisting of the wrist, especially when force is applied--such as in meat cutting, poultry boning, packing/wrapping operations, working as a cashier, and cake decorating. This constant bending inflames the tendons in your hand and wrist, causing the nerve that runs through a tunnel in the wrist (called the carpal tunnel) to be squeezed and pinched. When the nerve is pinched or squeezed, your hands go numb. The first symptoms of carpal tunnel syndrome, in fact, are nighttime numbness of the hand. Then over time as the nerve continues to get squeezed, the muscles in your hand start wasting away. If this condition is not treated promptly at the first signs of tingling or numbness, it can lead to permanent weakening of your hand. Surgery--often performed as a cure for this disorder--is rarely successful for work-related carpal tunnel syndrome. Carpal tunnel syndrome is often mis- diagnosed as arthritis. Carpal tunnel syndrome, however, only affects the first four fingers of your hand, while arthritis can affect the whole hand.

Thoracic Outlet Syndrome
This term issued to describe the condition caused by the pinching or squeezing of the nerves and blood vessels between the neck and shoulder. This can happen when work tasks require frequent reaching above the shoulder. Thoracic outlet syndrome is rare and difficult to diagnose with certainty. Studies have shown that many workers who were told they have thoracic outlet syndrome really had carpal tunnel syndrome. Carpal tunnel syndrome can cause shoulder pain--as well as wrist pain. Workers who have been diagnosed with thoracic outlet syndrome, therefore, may well have been mis-diagnosed. Because of this confusion, studies recommend that these workers be treated as though they have carpal tunnel syndrome.

DeQuervain's Disease
DeQuervain's disease is one of the most common tendon disorders of the hand. It develops when the tendons on the side of the wrist and at the base of the thumb become irritated from repetitive bending of the wrist. DeQuervain's Disease can usually be diagnosed by using a simple test which involves closing the fist around the thumb and bending the wrist towards the little finger. A person with this disorder will feel acute pain or tensing of the tendons on the side of the wrist.

Trigger Finger
Trigger finger is tendinitis of the fingers that is characterized by swelling, redness, and the locking of the affected finger in a bent or trigger position. Often the only way a person can open or straighten the affected fingers is by manually prying the fingers open.

AWKWARD POSTURES of the wrist or shoulders: Bending and/or twisting the wrists, twisting the arms, holding the elbows away from the body, reaching behind the body, lifting things above shoulder level, or using a pinch grip.

FORCEFUL EXERTIONS: Making forceful cuts, lifting heavy items, using a pinch versus a power grip, using a hand tool with hard, sharp edges.

REPETITION: Repeated and/or prolonged activity, making thousands of repeated motions a day. The more repetitive the task, the more rapid and frequent are the muscle contractions. Muscles performing highly repetitive tasks require more effort and consequently more recovery time or rest pauses than less repetitive tasks.

Other elements that contribute to MSDs are cold temperatures, slippery floors, poor grip on handles and vibrating tools. Many jobs require a combination of the above risk factors, such as forceful grip on a knife and repetitive cutting in an awkward posture, as in poultry processing or meatpacking.

Job Analysis and Redesign
The way to prevent cumulative trauma disorders is to redesign tools, work stations and jobs. By improving the fit between the worker and the job, not only is the well being of the worker improved but so is productivity. These are known as ergonomic solutions. Ergonomics is the science of fitting the job to the worker so the worker can do the job without injury.

The first step your company must take to prevent these disorders is to select the high-risk jobs and have a qualified ergonomist perform a careful analysis of the risk factors in each job. Input from workers on the jobs being studied and the union health and safety committee must be included in this analysis. In addition, worker and union input is critical in developing the best redesign solutions. Examples of effective job redesign include:

Checkstands: lowering the scales so it is flush with the laser scanner. This avoids repeated excessive reaching above the shoulder;

Meatpacking plants: a hydraulic tool that supplies the force necessary to separate bone from meat (paddle bone);

Other redesign efforts include adding workers to the line to reduce repetitious work, adjustable platforms and maintaining sharp knives. Your hands and wrists are especially vulnerable to poor design of tools and equipment because they contain a delicate collection of nerves, tendons, bones, ligaments, and blood vessels. To prevent hand and wrist disorders, tools and equipment should be designed to keep your hands and wrists straight--as though they were hanging relaxed at your side. Providing workers with adjustable work benches or tilting work surfaces may make a difference.

Medical Treatment
Because these diseases are caused by working conditions, no medical treatment will really work unless the job design and/or tool design are changed to prevent these problems from recurring. The best treatment for these disorders is to eliminate the twisting and bending that caused it in the first place. However, until these problems are eliminated, good medical treatment is absolutely necessary to treat these problems.

Medical treatments, especially for carpal tunnel syndrome, include wearing a wrist splint at night (if you wear it during the day, it can interfere with doing your job and cause more damage) and physical therapy. Hot wax treatments--now provided in some workplaces--are not recommended for the treatment of MSDs. In fact, it can further aggravate the condition, rather than cure it. In some instances, anti-inflammatory drugs may be recommended--such as cortisone. Applying these drugs through ultrasound--rather than injection--is recommended. Some companies are using vitamin B-6 to treat these health problems. Studies have shown this to be ineffective in treating work-related MSDs. In fact, the high dose needed to produce any results can be dangerous--it can cause serious nerve damage. Surgery is often prescribed as a last resort--but is not recommended because the condition can return.

The key to treating MSDs is to treat it at the first signs of pain and tingling in the hand. The longer good medical care is delayed, the worse the disease will get, the greater the likelihood permanent damage will result.