This material is for training purposes only. Its purpose is to inform Oregon employers of best practices in occupational safety and health and general Oregon OSHA compliance requirements. This material is not a substitute for any provision of the Oregon Safety Employment Act or any standards issued by Oregon OSHA. For more information on this online course and other OR-OSHA online training, visit the Online Course Catalog.

MODULE ONE: DEFINING ERGONOMICS

Webster's New World Dictionary (College Edition) defines ergonomics as "The Study of the problems of people in adjusting to their environment; especially the science that seeks to adapt work or working conditions to suit the worker.

Ergonomics may also be thought of as the science of fitting the job to the individual worker. When there is a mismatch between the physical requirements of the job and the physical capacity of the worker, musculoskeletal disorders (MSDs) can result.

Who is at risk?

Workers who must repeat the same motion throughout their workday, who must do their work in an awkward position, who must use a great deal of force to perform their jobs, who must repeatedly lift heavy objects or who face a combination of these risk factors are most likely to develop MSDs. The level of risk depends on how long a worker is exposed to these conditions, how often they are exposed, and the level of exposure.

What Are MSDs?

MSDs include a group of conditions that involve the nerves, tendons, muscles, and supporting structures such as intervertebral discs. They represent a wide range of disorders, which can differ in severity from mild periodic symptoms to severe chronic and debilitating conditions. Examples include:

carpal tunnel syndrome
tenosynovitis
tension neck syndrome
and low back pain

MSDs are often confused with ergonomics. Ergonomics is the science of fitting workplace conditions and job demands to the capabilities of workers. In other words, MSDs are the problem and ergonomics is a solution.

Contributing factors are aspects of work tasks that can lead to fatigue, MSD symptoms and injuries, or other types of problems. These factors may be present in one or more of the tasks employees must perform to accomplish their jobs. The contributing factors you and your employees should be aware of include:

Awkward postures
Repetitive motions
Forceful exertions
Pressure points (e.g., local contact stress)
Vibration

There are also environmental factors associated with the workplace that can cause problems.

Extreme high temperatures can increase the rate at which the body will fatigue. Exposure of the hands and feet to cold temperatures can decrease blood flow, muscle strength, and manual dexterity. These conditions can also cause excessive grip force to be applied to tool handles or objects. Another problem may be caused by tools or equipment that exhaust cold or hot air directly onto the operator.

In addition, the lighting in a workplace may be too dark or too bright for the work task. This may result in employees assuming awkward postures to accomplish work tasks and a loss of product quality. We will cover these factors in more detail in upcoming modules.

What Are Work-Related Musculoskeletal Disorders (WMSDs)?

Occasionally, in reading safety literature, you will come across this term. WMSDs are nothing more than MSDs caused or made worse by the work environment. WMSDs can cause severe and debilitating symptoms such as:

pain, numbness, and tingling; reduced worker productivity
lost time from work
temporary or permanent disability
inability to perform job tasks
an increase in workers compensation costs.

The interaction of three risk factor areas

Ergonomics studies the various risk factors brought to a job. There are three areas within which ergonomics risk factors exist:

Risk factors inherent in the worker
Risk factors inherent in the task
Risk factors inherent in the environment

Workers come in all shapes and sizes, each with unique attributes that present certain ergonomic risk factors to a given job. The task(s) of the job, itself, can present risk factors that increase the likelihood of an injury. Finally, the workplace environment, within which the worker and job exist, may also contain exposures to risk factors. We will cover each of these three risk factor categories in the course.

The impact of ergonomics

Oregon statistics

Claims costs (incurred losses) are the costs of all benefits paid out of workers' compensation premiums to an injured worker, over the life of a claim. In Oregon, losses for MSDs were around $190 million in 2000, and more than $1.8 billion from 1990 through 2000. The majority of MSDs have been sprains, strains, and tears caused by overexertion. These claims alone account for 60 percent of all the MSD claims accepted between 1996 and 2000. Recently however, the share of MSDs due to overexertion has been shrinking as the proportion of disorders resulting from repetitive motion and bodily reaction is on the rise. Of MSD claims accepted through 1996 to 2000, the back (22,053 claims) and wrists (6,788) were the parts of body stricken most often. More information on Oregon Statistics.

National statistics

Musculoskeletal disorders are among the most prevalent medical problems in the U.S., affecting 7% of the population. They account for 14% of physician visits and 19% of hospital stays. 62% of persons with MSD report some degree of limitation on activity compared with 14% in the population at large.

Often MSDs can be prevented by simple and inexpensive changes in the workplace. Adjusting the height of working surfaces, varying tasks for workers and encouraging short rest breaks can reduce risks. Reducing the size of items workers must lift or providing lifting equipment also may aid workers. Specially designed equipment, such as curved knives for poultry processors, may help.

In 2001, the Bureau of Labor Statistics (BLS) reported there were about 333,800 newly reported cases of occupational illnesses in private industry nationally. Manufacturing accounted for 54 percent of these cases. Disorders associated with repeated trauma, such as carpal tunnel syndrome and noise-induced hearing loss, accounted for 4 percent of the 5.2 million total workplace injuries and illnesses in 2001. They were, however, the dominant type of illness reported, making up 65 percent of the 333,800 total illness cases.

Last Words

Medical costs and workers’ compensation claims for serious MSDs may total $15,000 to $85,000 or more. It makes sense to give serious consideration to the risk factors in your workplace and the information in this course will help you do that. Before moving on to the next module, take the time now to answer the quiz questions below. Later, you'll enter these answers in the Final Exam and Quiz page online.

MODULE Quiz

1. Ergonomics is the science of fitting the job to a group of workers.

a. True
b. False

2. Musculoskeletal disorders can result when there is a mismatch between the physical _______ of the job and the physical ________ of the worker.

a. demands, requirements
b. requirements, capacity
c. requirements, requirements
d. demands, demands

3. Workers are likely to develop MSDs when they:

a. work in an awkward position
b. use a great deal of force
c. repeatedly lift heavy objects
d. Any of the above

4. Which of the following is not one the three areas within which ergonomics risk factors exist?

a. the worker
b. the procedure
c. the task
d. the environment

5. Musculoskeletal disorders are among the most prevalent medical problems in the U.S., affecting _____ of the population:

a. 3 percent
b. 7 percent
c. 40 percent
d. 72 percent

6. According to the text, MSDs can often be prevented by simple and inexpensive changes in the workplace:

a. True
b. False

7. Work-Related Musculoskeletal Disorders are musculoskeletal disorders caused or made worse by the work environment.

a. True
b. False

8. According to the text, MSDs include a group of conditions that involve all of the following, except:

a. nerves
b. tendons
c. muscles
d. skin

9. According to the text, all of these factors may contribute to MSDs, except:

a. vibration
b. unique motions
c. awkward postures
d. forceful exertions

10. Recently the share of MSDs due to overexertion has been increasing as the proportion of disorders resulting from repetitive motion and bodily reaction.

a. True
b. False

Congratulations! You've finished the Module One. In Module 2, we'll take a look at the ergonomics risk factors the worker brings to the job.

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