- What is ergonomics?
Ergonomics is the study of human work. The term ergonomics comes from the Greek word "ergos" meaning work and "nomos" meaning natural laws of. Ergonomics is concerned with the effective use of the physical and psychological capabilities of the human as they apply to work. It involves the worker's interaction with tools, equipment, environment, jobs, tasks,
work methods, work rates and other systems.
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- What is a work-related musculoskeletal disorder (WMSD or MSD)?
These are disorders of the soft tissues or bones that occur at least partially due to work. Soft tissue disorders may include sprains, strains, inflammation, degeneration, pinching, and tears. Disorders of the bones are typically bruises, micro-fractures, cracks or splintering. These disorders may show up as an employee complaint, injury, illness, discomfort, chronic pain, shooting pain, fatigue, sprain, strain, or as numbness and tingling of hands or feet.
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- How long does it take to develop a work-related musculoskeletal disorder?
This is difficult to predict. An employee may notice symptoms such as muscle, joint or tendon soreness within the first several weeks of a new job. Workers with pre-existing medical problems may be at higher risk
of developing symptoms than healthy workers. Some disorders may take several years before symptoms are identified. Some employees may never develop a WMSD.
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- Do back belts prevent low back pain? Should employees be required to wear them? Are back belts considered personal protective equipment?
Evidence shows that wearing a back belt neither reduces injury rates nor the number of lost workdays. Employees should only be required to wear a back belt as a condition of employment if a physician prescribes it for a previous medical condition. Under no circumstances are back belts considered personal protective equipment.
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- What is the difference between carpal tunnel syndrome and tendinitis?
Carpal tunnel syndrome is the entrapment of the median nerve of the hand and wrist in the passageway (tunnel) through the carpal bones of the wrist. It results in
symptoms such as pain, tingling and night numbness in the fingers and pain on gripping. Tendinitis is the inflammation of a tendon, usually associated with repetitive, forceful exertions, often involving rotation around a joint such as the wrist or elbow.
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- I've heard that Vitamin B-6 can prevent carpal tunnel syndrome. Should employees receive vitamin supplements?
No. A few years ago, some reports claimed that Vitamin B-6 could prevent carpal tunnel syndrome. A recent study contradicted those results. Thus, there is no clear answer.
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- Will wearing a wrist splint prevent carpal tunnel syndrome?
No. Although wrist splints help maintain a neutral wrist posture, there is some evidence that they do not change the pressures inside the carpal tunnel. Moreover, wearing a wrist splint in jobs with risk factors may transfer the stress to other parts of
the body and cause injury. If the wrist cannot bend easily, and the job still requires wrist flexion, for example, the upper arm orientation has to change. To avoid creating disorders at other body locations, it is necessary to analyze the job requirements and reduce risk factors. Wrist splints are not considered personal protective equipment, and should only be worn if prescribed by a medical practitioner.
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- Is stress a factor in developing work-related musculoskeletal disorders?
Some studies have shown a relationship between psychosocial factors and WMSDs. Psychosocial factors, such as the amount of control over one's job, appear to play a role. Control over how the job is done is particularly important in situations where the demands of the job are high. Examples are tasks involving quotas or piecework compensation. In these cases, the worker has little control, the job is often highly stressful, and these conditions may contribute
to the development and reporting of WMSDs. Supervisory and peer support at work may also be an important factor in helping to reduce risk factors for WMSDs.
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- Are work-related musculoskeletal disorders caused by things people do at home (e.g., knitting, gardening)? Are smoking or obesity potential factors?
Clearly, risk factors for the development of WMSDs are not found exclusively at work. Home/life activities usually related to recreation or hobbies, such as playing certain string instruments, knitting, carpentry, or playing racquet sports may involve risk factors related to musculoskeletal disorders. There are also personal risk factors that may contribute to these types of disorders. For example, aging, physical health, smoking and obesity are risk factors for the development of WMSDs. However, the employer still should try to eliminate workplace risk factors that contribute to the development or aggravation of WMSDs.
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- Is there a difference between men and women in the incidence rate of work-related musculoskeletal disorders?
There are some differences in the incidence rates. However, this may merely reflect differences in employment patterns. For example, the work force in highly repetitive data entry operations (which may create upper extremity problems) is often predominantly female. Therefore, it is difficult to separate the effect of biology from other demographic and economic factors.
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- Do stretching exercises help prevent work-related musculoskeletal disorders?
It is better to modify jobs to eliminate risk factors for disorders than to encourage stretching exercises. However, just like in athletics, stretching can play an important role in preventing, but not eliminating, WMSDs.
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- How
frequent and long should rest periods be to prevent work-related musculoskeletal disorders?
Nobody knows for sure. However, physiological principles suggest that it is better to take short breaks frequently instead of a few breaks of longer duration. Shorter frequent breaks give the tissues of the body time to recover immediately after use. It may be better to think of such breaks as "recovery" breaks rather than "rest" breaks. It is important to design recovery breaks into jobs rather than merely telling employees to take breaks. Unless recovery breaks are a mandatory part of the work process, it is easy for supervisory and peer pressure to discourage taking recovery breaks.
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- What is an ergonomic chair?
Look for adjustability and lumbar back supports. Good chairs should be able to accommodate a wide range of shapes and sizes of people. Probably the most important adjustment is seat pan height.
It is also important to have the ability to adjust seat pan angle. A padded support for the low back, which is called a lumbar back support, helps reduce the stress on the spine. Before buying a chair, however, it is important to think about the tasks the employee performs and the work environment in which the chair will be used. Specifically, it is critical to remember that work organization affects the amount of time spent sitting in a chair. Organizing the work so that workers can change postures and get up from their chairs may be more important than purchasing the best ergonomic chair available.
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- What is an ergonomic computer keyboard?
Computer keyboard manufacturers have started promoting certain keyboards as "ergonomic." Although some of this is advertising hype, a number of innovative keyboard designs have been developed. Most serious efforts at redesigning keyboards have centered on minimizing wrist motions and
awkward wrist postures. Such designs may reduce risk factors such as wrist deviation. Some of these keyboards have documented improvements in productivity (e.g.. typing rates), but little research has been conducted to demonstrate that "ergonomic" keyboards actually prevent injuries. Moreover, it is critical to remember that issues of work organization can significantly affect the amount of time spent keying, which may be the most important factor.
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- Why are there so many more work-related musculoskeletal disorder claims now than there were 20 years ago?
There have been WMSDs for a long time. A physician by the name of Bernardino Ramazzini described them more than 250 years ago. There has been an increase in claims for these disorders over the last several decades. One reason for the increase is changes in production rates. In many industries, competitive pressures consistently increase production line speeds, which increases
repetitiveness and reduces rest breaks for tissues to recover. An increase in public awareness may also contribute to increased reporting.
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- How heavy is too heavy a load?
It depends on a variety of factors. For example, a weight held far from the torso is more stressful than one held close to the torso. Lifts from floor level or above the shoulders, and lifts that require a person to twist the body also are more stressful. Lack of, or poorly designed handles on the object also can increase the stresses on the body. Loads should be lighter when lifts are frequent. The National Institute of Occupational Safety and Health (NIOSH) has developed a Lifting Equation for Manual Materials Handling, which provides a method for calculating a recommended maximum weight to be lifted under a variety of conditions. Call 1-800-35-NIOSH (1-800-356-4674) for more information.
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- If a doctor says my employee cannot perform a job because of work-related musculoskeletal disorders, do I have any options?
Yes. Ultimately, the best medicine for injured workers is to return to work as soon as safely possible. Analysis of claims shows that the longer a worker is in the industrial insurance system, the harder it is for him or her to return to work. You are encouraged to develop strong return-to-work policies and procedures which provide opportunities for employees who are temporarily disabled due to on-the-job injuries.
Your workers compensation insurer can assis with return-to-work programs. Another option would be to contact Oregon OSHA or private professional ergonomist or physical therapist for help.
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For more information on ergonomics program guidelines or current occupational safety and health regulations, contact the Oregon OSHA field office nearest you.
Thanks to the Department of Labor & Industries, Washington Industrial Safety and Health Division (WISHA) for the content of this page. |
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