Carpal Tunnel Syndrome: A Occupational Illness Essay, Research Paper

The carpal tunnel is a passageway that runs from the forearm through the wrist. Bones form three walls of the tunnel and a strong, broad ligament bridges over them. The median nerve, which supplies feeling to the thumb, index (4th digit), and ring fingers (3rd digit), and the nine tendons that flex the fingers, passes through this tunnel. This nerve, also, provides function for the muscles at the base of the thumb (the Thenar muscles). Usually, carpal tunnel syndrome (CTS) is considered an inflammatory disorder caused by repetitive stress, physical injury, or medical conditions that cause the tissues around the median nerve to become swollen. The protective lining of the tendons within the carpal tunnel can become inflamed and swell or the ligament that forms the roof over the median nerve becomes thicker and broader and presses on it. Dr. L, an orthopedic surgeon stated ” It’s like stepping on a hose. Slows the flow of water through a garden hose. The compression on the (median) nerve fibers by swollen tendons and thickened ligament slows down the transmission of nerve signals through the carpal tunnel.” The result is pain, numbness, and tingling in the wrist, hand, and fingers. This does not concern the little finger (5th digit) because the median nerve does not affect it.

It is often very difficult to determine whether the primary cause of CTS is primarily due to work conditions or an underlying medical problem. CTS almost always occurs in adults and most adults work; CTS, then is very likely to be associated with the work place whether or not it is actually caused by work itself. Estimates of work-related CTS vary wildly. Some studies suggest that more than half are due to workplace factors and others that few cases of CTS are actually caused by conditions on the job. In one study, for example, obesity or diseases such as diabetes, hypothyroidism, and arthritis occurred in the majority of people with work-associated CTS. Such conditions are known contributors to CTS. It is most likely that many cases of CTS occur from a combination of factors, including a predisposing medical condition exacerbated by work stress and psychological and social stressers. In many patients with CTS, an underlying cause for the disorder cannot be discovered.

Disorders related to work that requires repetitive motion are increasing. They account for nearly half of all reported work related illness, and CTS is estimated to account for over 41% of these repetitive motion disorders. Researchers have defined six key risk factors in the workplace for the development of these disorders, including CTS: (1) repetition, (2) high force, (3) awkward joint posture, (4) direct pressure, (5) vibration, and (6) prolonged constrained posture.

Through many of the studies I have read, many believe that incorrect posture may play a large role in the development of CTS, particularly in people who work at computer and other types of keyboards. The tendency to roll the shoulders forward, round the lower back, and thrust the chin forward can shorten the neck and shoulder muscles compressing nerves in the neck. This can affect the wrist, fingers, and hand. It has been difficult to obtain reliable data on the relation between repetitive hand and wrist tasks and CTS.

Studies indicate that psychosocial factors in the workplace, such as intense deadlines, interpersonal relationships, and job design, are major contributors to carpal tunnel pain. Such psychosocial conditions are more likely to be important factors in contributing to CTS in office workers, although they also complicate the condition in workers whose work is primarily physical. This information will be in detail with further reading.

Bone dislocations and fractures can narrow the carpal tunnel exerting pressure on the median nerve. Certain other medical conditions, such as rheumatoid arthritis, diabetes, and hypothyroidism, can also cause the inflammation in the carpal tunnel that results in median nerve entrapment. These are all autoimmune diseases, meaning that the body’s immune system is abnormally attacking its own tissue. Some experts believe that CTS may actually be one of the first symptoms in a number of these diseases. CTS can also be caused by long-term hemodialysis and disease such as multiple myeloma, Waldenstrom’s macroglobulinemia, and non-Hodgkin’s lymphoma, which cause a build up of waxy starch like protein called Amyloid in the bone and joint tissues. Acromegaly, a disease that causes abnormally long bones, is a cause of CTS. A virus known as human parvovirus was suspected in a few cases of CTS that developed in both hands. Certain medications that effect the immune system, such as interleukin-2, which is administered to cancer patients, may cause temporary CTS. There have been some reports of CTS caused by anticlotting drugs, such as warfarin.

It was reported that people with a family history of CTS have a higher risk of getting it. This indicates a genetic susceptibility exists in some people. Some researchers are particularly interested in abnormalities in certain genes that regulate myelin, a fatty substance that serves as insulation for nerve fibers. Some people may be born with abnormalities of the carpal bones. It was also reported that the fluid retention during pregnancy or hormonal changes associated with menopause could cause swelling and symptoms of CTS. (Brown, 1998)

Symptoms of CTS usually progress gradually over weeks and months, and some cases years. The first symptoms may be pain in the wrist and hand or numbness and tingling of the fingers. Again, except for the 5th digit. Patients may also experience a sense of weakness and a tendency to drop things. They may lose the sense of heat and cold or feel that their hands are swollen even though there is no visible swelling.

Symptoms may occur not only when the hand is being used but also when it is at rest. In fact, the disorder may be distinguished from similar conditions by pain occurring at night after going to bed. In some cases, labor related CTS symptoms first occur outside of work, so patients may fail to associate the symptoms with work related activity. Anyone with recurrent or persistent pain, numbness and tingling, or weakness of the hand should consult a physician for a diagnosis.

IN 1988, 2.8 million people reported symptoms to their doctors that they believed were those of CTS. In a study done in 1998, “experts estimated that between 7% and 16% of the population experience CTS. The incidence appears to be increasing. People over age 54 were at higher risk than younger adults. The wide variation severity and the difficulty in diagnosis make it hard to pinpoint specific figures.” (Simon, 1998)

The workers at high risk are those whose occupations combine force and repetition of the same motion in the fingers and hand for long periods. Such workers include those in the construction workers, meat and fish packaging, and dentists/dental technicians using vibrating tools. The vibrating tools range from jackhammers, chain saws, saws, drills, and machinery. Meat packers complained of pain and loss of hand function and loss of hand function as long ago as the 1860’s. Even today, the incidence of CTS in meat, poultry, and fish packing industries may be as high as 15%. Workers in these industries and those who assemble airplanes have the highest risk of CTS, according to one study. In addition, high risk for CTS has been reported in other assembly line workers, cake decorators, postal workers, and beauticians/barbers. In essence, any workers who use their hands and wrists repetitively are at risk. People who engaged intensively in certain domestic occupations, including knitting, sewing and needlepoint, cooking, housework, carpentry, and extensive use of power tools are also at risk. Many leisure activities in the home can contribute to the development of CTS, including computer games, sports, and card playing.

Even though the increased number of people using computer keyboards has provoked much publicity about their risk for CTS, it is actually lower than those in occupations involving heavy labor. The force of the movement may be a particular factor for CTS in typists. On study observed that typists with CTS struck the keys with greater force than those without the disorder. Some workers may not even be aware of the amount of force they exert while performing their jobs. For example, “to type 60 words per minute for eight hours equals a 10 mile run on your fingers” (Stotko, 1996).

Many reports indicate that women have a significantly higher risk for CTS than men do. The explanation for the greater risk is unknown. The hand intensive nature of housework and typing may contribute to a higher incidence in women. Hormonal changes appear to play a major role as evidenced by an increased incidence in CTS symptoms while taking oral contraceptives and during pregnancy, the postpartum period, and menopause. In one study of pregnant women with CTS, the condition developed at any point during pregnancy; no single trimester posed a higher risk than others. (Brown, p. 99)

In the study by Dr P. Shellito, his report indicated that obesity is highly linked with CTS. CTS is also more common in those with square wrists than in those with the more common rectangular wrists. A square wrist is when the thickness and width are about the same. There has been some suggestion that the size of the carpal tunnel may play a role in the disorder, but there has not been any difference between women who had CTS and those who did not have it. Some researchers claim that poor upper back strength makes people more susceptible to injuries in the upper extremities, including CTS. Cigarette smoking, poor nutrition, previous injuries, and stress can increase one’s risk for CTS.

CTS can range from a minor inconvenience to a disabling condition, depending on its cause and persistence and the individual characteristics of the patient. Many cases of CTS are mild, and some resolve on their own. For example, once the pregnant women gives birth the swelling in her wrists subside and so do the CTS symptoms. If severe cases are left untreated, muscles at the base of the thumb may atrophy and sensation may be permanently lost. CTS can become so crippling that people can no longer do their job or even perform simple tasks at home. The syndrome may force people to undergo surgery and miss many days of work and can even prevent them from working at all if their hand functions are permanently impaired.

Occupational related causes of CTS have had a severe impact on American businesses. Workers with CTS become easily fatigued, experience pain and discomfort, and may not perform up to par. “Nearly half of all employees diagnosed with CTS had changed jobs or were absent 30 months after diagnosis”. (Stampton, 1998) Because of the difficulty in determining the exact cause of CTS, employers are concerned about high worker’s compensation costs due to CTS, which may or may not be due to working conditions. Those receiving compensation are also more likely to be absent from work longer than those not being paid, particularly if the employer is opposing the case. “The medical costs and loss of productivity because of CTS has been estimated to average $29,000 per injured worker. Work related injuries, including CTS, that involve joints and muscles cost the country about $20 billion every year.”(Stampton)

Companies are now taking action to help prevent repetitive stress injuries. In a survey, 84% reported that they were modifying equipment, tasks, and process; 83% were analyzing their workstations and jobs, and 79% were buying new equipment. (Stampton) No single method of prevention exists for CTS. It is important to use common sense and ergonomic controls to help minimize risk factors predisposing to work related CTS or other cumulative trauma disorders. A patient can learn how to adjust the work area, handle tools, or perform tasks in ways that put less stress on the hands and wrists. Exercise programs to strengthen the fingers, hands, wrists, forearms, shoulders, and neck may help prevent CTS. It should be stressed that there has been no evidence that any of these methods can provide complete protection against CTS. If the underlying cause is a medical condition, controlling the problem can prevent CTS.

Ergonomics is the study and control of posture, stresses, motions, and other physical forces on the human body engaged in work. Altering the way a person performs repetitive activities may help prevent inflammation in the hand and wrist from progressing into full-blown CTS. It should be suggested that businesses replace old tools with ergonomically designed new ones. In order for businesses to eliminate their employees from CT, they should provide literature and oral instructions on prevention. Exercise, correct posture, and proper body movement are factors to incorporate in their programs.

Anyone who does repetitive tasks should begin with a short warm up period, take frequent break periods, and avoid overexertion of the hand and finger muscles whenever possible. Employers should be urged to vary tasks and work content.

Good posture is extremely important in preventing CTS, particularly for typists and computer users. A keyboard operator should sit with the spine against the back of the chair with the shoulders relaxed. His/her elbows should be along the sides of the body, and wrists straight. The feet should be firmly on the floor or on a footrest. Typing materials should be at eye level so that the neck does not bend over the work. Keeping the neck flexible and head upright maintains circulation and nerve function to the arms and hands. Poorly designed office furniture is a major contributor to bad posture. Chairs should be adjustable for height, with a supportive backrest. Employers should be advised that the higher cost of a custom designed chair for a worker whose body does not fit a standard chair is still far less than the medical or absentee costs of a n injured employee.

The force placed on the fingers, hands, and wrists by a repetitive task contributes to CTS. To alleviate the effect of force on the wrist, tools and tasks should be designed so that the wrist position is the same as it would be if the arms dangled in a relaxed manner at the sides. No task should require the wrist to deviate from side to side or to remain flexed or highly extended for long periods. Keyboard operators should adjust the tension of the keys so that depressing the keyboard does not

Cause fatigue. The hands and wrists should remain in a relaxed position

to avoid excessive force on the keyboard. For computer users, replacing

the Mouse with a trackball device and the standard keyboard with a jointed type are helpful substitutions. Wrist rests, which fit under most keyboards, can help keep the wrists and fingers in a comfortable position.

The handles of such tools as screwdrivers, scrapers, paint brushes, and buffers should be designed so that the force of the worker’s grip is distributed across the muscle between the base of the thumb and the little finger, not just in the center of the palm. People who need to hold any objects, such as a pencil, steering wheel, or tools, for long periods of time should grip them loosely as possible. In order to apply force appropriately, the ability to feel an object is extremely important. Tools with textured handles are helpful. Working at low temperatures, which reduces sensation in hands and fingers, should be avoided if possible. Tools and machines should be designed to minimize vibrations. Protective equipment, such as shock absorbers, can reduce vibrations. Bicyclists who ride frequently on rough roads should wear thick cycling gloves to lessen the shock transmitted to the hands and wrists.

Hand and wrist exercises can strengthen the muscles in the wrists and hands, as well as the neck and shoulders, improving blood flow to these areas. Performing the attached simple exercises for four to five minutes may be helpful and should be implememented in businesses that have employers that are prone to CTS.

Carpal Tunnel Syndrome exacts a psychological toll on the client. Anyone who cannot use his hands is bound to be depressed and suffer from low self esteem. A worker with CTS may be forced to give up his or her livelihood. An employee experiencing hand pain may try to ignore it and put more stress on the wrists, leading to poor work performance. Because the disease is not readily visible, coworkers and managers may harass CTS sufferers and accuse them of faking to get out of work. At home people may suffer from daily pain and loss of freedom. They cannot contribute actively to their families because they may not be able to drive a car or do ordinary tasks, such as picking up groceries. They may become still more depressed if they have to give up enjoyable sports and hobbies. They may be depressed and embarrassed from there lack of performance when they cant lift a child.

Support groups for CTS and other sufferers of repetitive stress injuries can be very helpful in exchanging information and offering advice and comfort. Stress management techniques can be also be useful in dealing with the psychologic and emotional issues accompanying these injuries.

* Brown, James, “Pregnancy related Carpal Tunnel Syndrome” Journal of Hand Surgery, 1998,

Feb; 23(1): p. 98-101

? Shellito, P., “A Case study of obesity as a risk factor for carpal tunnel syndrome in a population of 600 patients presenting for independent medical examination” Journal of Hand Surgery, 1997, March: 24(1): p.122-31

? Simon, H., “Incidence of diagnosed Carpal Tunnel Syndrome in a general population.” Epidemiology, 1998, May; 9(3):342-5

? Statko,Lori, “Safe’ typing: It’s in the hands” CTDNews, 1996 LRP Publications, attached article.