Personalized Ergonomics Can Ward Off CTS in the Workplace
By Christine McLaughlin
The incidence of workplace repetitive stress injuries, like carpal tunnel syndrome, are far too common in the United States and are largely due to increased computer use. In fact, one in every three workers' compensation dollars pays for such RSIs, according to the Occupational Safety and Health Administration.
But these injuries don't have to be so widespread. Preventive efforts like ergonomic workstations and principles can help thwart the injuries from the start.
"The word 'ergonomics' really derives from the Greek word 'ergonomis.' 'Ergo' means work and 'nomis' is the law or study. So ergonomics is the study of work," explained Gary Herrin, PhD, professor of industrial and operations engineering at the University of Michigan, Ann Arbor. "For engineering purposes, [ergonomics] means the design of work that is healthy, safe, productive and high quality."
Ergonomic engineers play a large role in the way equipment is made or workstations are designed and try "to fit the job to the person rather than the person to the job," Dr. Herrin said. It is when the reverse happens that injuries develop.
Industrial or ergonomic engineers who deal with ergonomics will design work equipment to reduce all risk factors in the workplace that include force, repetition, vibration, postural problems, temperature extremes and mechanical stress, he explained. In addition, ergonomic engineers also have a background in physiology and anatomy in order to develop equipment that follows these principles.
MANY TIMES industrial engineers of manufacturing companies are responsible for designing hand tools and computer equipment to be more biomechanically correct. "Many manufacturers of equipment are now much more sensitive to the issues of disorders like carpal tunnel syndrome and are doing their best to design tools to minimize the risk factors," noted the engineer.
In addition to the mechanical ergonomics helping a person do a job more safely by minimizing risk for RSIs, biomechanics are equally as important, which is where physical and occupational therapists take over. PTs and OTs generally consider the posture of the patient as one of the most important aspects of preventing carpal tunnel syndrome.
"Ergonomics means [to me] using the body in the manner it was meant to be used. Not just working harder but working smarter with a more biomechanically correct position," noted Jay Kauffman, PT, administrator at HealthSouth in Warminster, PA.
The main objective is to eliminate the factors that precipitate the onset of the condition, which is the compression of the median nerve that leads to ischemia and decreased blood flow, he said. "The average cost of treating CTS is $12,000. So, it's in our best interest to prevent it from occurring in the first place."
THERAPISTS WHO work with such patient populations help them reduce repetitive types of activity that would cause the compression of the nerve, and prescribe stretches and exercises to increase the blood flow to the area to prevent the symptoms from exacerbating. When patients come to a PT or an OT for treatment they typically already have symptoms of CTS, which oftentimes can be alleviated through proper ergonomics, according to Kauffman.
"We're getting patients earlier than we used to because more people are aware of the problem. In the past, people thought [CTS] would simply go away, but it [actually] would progressively get worse. Now people are seeking medical attention sooner, which is more effective in eliminating CTS symptoms. Many employers even ask us to do carpal tunnel screenings," noted Kauffman, adding that he often conducts worksite evaluations to determine problem areas for patients.
In general, he will evaluate the patient's posture when he does an on-site evaluation. The individual should be sitting with the whole foot touching either the floor or a foot rest; hips should be slightly higher than the knees; the back should be supported by the back of the chair in a neutral spine or slightly arched position; arms should be at an angle slightly larger than 90 degrees; and forearms should be supported by rests.
He explained that flexible forearm supports are available that attach to chairs or keyboards and move with the user. This provides the necessary support to ease some of the muscle strain in the shoulders from keeping the arms elevated.
While wrist rests have been advocated in the past to help relieve pressure from the wrists, they may not actually be very effective. Debra
Lieberman, OTR/L, staff therapist at the National Rehabilitation Hospital/Suburban Regional Rehab in Bethesda, MD, said that it's important for people not to put pressure on the pads of their hands even when using a wrist rest. "People thought that wrist rests would help take pressure off from using the desk to rest the hands while typing. But it has been determined that people are still putting pressure on their wrists with the rests," she commented. "It's more important to move the hands across the keyboard while typing rather than leaning on anything at all."
Many people don't realize what kind of damage they may be doing to their bodies while typing, said Lieberman, who evaluates patients on the computer in the clinic. Consequently, she uses videotape to show patients what they are doing incorrectly (ergonomically speaking) and why. The video is positioned to display head or trunk posture, as well as hand and wrist position. The patient can watch through the video monitor while the therapist gives postural cues. "For instance, we can show them when they reach for a certain key, they're doing damage to the wrist and extensor tendons get inflamed."
ADAPTATIONS to keyboards have recently been made that help with postural concerns. Keyboards with a "negative tilt" are effective in minimizing fatigue because the hands are in a more neutral position while typing, said Lieberman. A negative tilt is when the front part of the keyboard is elevated. "This way the hands are straight and not reaching up. So even if a person took a break and rested the hands on a wrist rest, it would be in more neutral position [with less stress on the nerve] rather than in extension with a traditional keyboard."
If people relax their arms at their sides with elbows close to the body and their backs against the chair, they should not get as fatigued and have to use a wrist rest for support, suggested Lieberman. The keyboard should be close to the lap area when typing so that the individual won't feel the need to lean on the wrists and can move the hands freely.
Keyboards available that are more ergonomically designed can also be helpful in reducing the stress of the carpal tunnel. Split keyboards consist of two separate pieces that resemble a "wave" shaped curve rather than the conventional straight rectangular piece. It is believed that this shape puts the wrists and arms in a more natural, biomechanically correct position.
FOR THOSE patients who do develop symptoms of CTS, both Lieberman and Kauffman noted that they prescribe splints to be used at night while sleeping. The splints take pressure off of the carpal tunnel by keeping the hands in a neutral position. "When you're asleep your hands can go in all sorts of positions. The splint gives patients an awareness of how their hands should be held," said Lieberman. She added that the splints along with home exercise programs have proved successful for patients with beginning stages of CTS.
While one of the main objectives in preventing CTS is to take the pressure off of the wrists, it's also important to stretch and exercise the fingers because typing alone can cause inflammation and compress the nerve.
Although carpal tunnel syndrome is commonly associated with manifesting in the wrists, hands and fingers, Kauffman said he believes the syndrome is also connected with the neck and shoulder. "When people are doing repetitive motion with the hands they tend to have poor posture, which is exhibited all the way up the neck and shoulder."
Consequently, one of the best ways to prevent strain in all of these areas is for computer users to get up from their work area, move around and perform exercises to increase blood flow throughout the neck and upper extremities. The exercises eliminate the chances of reducing the blood supply to the median nerve, and the hands and fingers from becoming stiff or painful. Kauffman recommends to his patients range of motion and flexibility exercises for the elbow, shoulder, neck, head, upper back and fingers.
But a prevalent problem in people who type for most of their day is that many are reluctant to take breaks because they are so engrossed with their work. Because of this, Kauffman designed a computer alarm to warn the user when they should take a break and stretch. He collaborated with a graphic artist and a computer programer to develop the program, which will soon be available nationwide.
The program can be set for the alarm to activate in intervals of 15, 20, 30 or 45 minutes. A point and click feature appears where the user can go through a series of stretching exercises if they so desire, he said.
OTHER COMPUTER programs exist to help people prevent CTS. Voice activation systems allow the user to type by talking. The purpose is to replace the keyboard and use the vocal cords instead of the fingers. Not only are these systems useful in preventing CTS, but they also present people who don't have use of their hands with an alternative to typing. "These systems are a lot cheaper today. I have seen them priced as low as $90," Lieberman said. Also, new innovations like a 'foot' mouse are available to ease CTS symptoms by taking the stress off of the hand and using the foot, instead.
Therapists should stress to their patients that whatever ergonomic equipment they purchase they should be able to return it if they're not completely satisfied, because the equipment could be "causing more harm than good," recommended Lieberman. "If the equipment doesn't give them a good feeling in the work environment, after initial use, they should return it."
By combining the right equipment with the right techniques, early CTS symptoms can be alleviated or prevented in most cases. But as a rule, therapists also need to teach patients that it is more beneficial for their bodies and careers to take more breaks from repetitive activities during the day, Lieberman noted.
Kauffman agreed and concluded, "We must tell our patients to listen to their bodies. When there is pain or a burning sensation in the wrists or hands that is the body's way of telling us it has had enough."
Add Some Citrus to List
In Preventing Breast Cancer
Drink up. Orange juice and grapefruit juice, two tangy beverages enjoyed by millions of Americans each morning, may actually delay the growth of breast cancer cells and reduce LDL, or bad cholesterol, according to new research presented by the International Congress of Nutrition.
"The implications are potentially enormous because a powerful weapon against breast cancer and high cholesterol may be as close as your kitchen," said research team member Dr. Kenneth Carroll, director of the Centre for Human Nutrition at The University of Western Ontario, Canada.
In the breast cancer study, researchers analyzed the effects of orange juice and grapefruit juice and the drinks' constituent flavonoids (naturally occurring compounds found in many fruits and vegetables) in inhibiting human breast cancer cells in mice.
"Mice that received orange juice or grapefruit juice in place of water had 50 percent fewer tumors and metastases," said Najla Guthrie, lead researcher on the center's cancer study. The study also indicated that in test animals fed orange juice LDL cholesterol was reduced by 43 percent and in those fed grapefruit juice LDL cholesterol was reduced by 32 percent.
"We are very excited by these initial results of both studies, and we'll continue to look into what components in the juices make them so effective," said Dr. Carroll. "Right now, what we know is that orange juice and grapefruit juice appear to be particularly effective."