Originally created by the Minnesota Safety Council for publication in
the Minnesota Counties Insurance Trust publication Wellsping. Used with permission.
Ergonomics has become a term most often associated with tools like a computer, keyboard, telephone and key pad. In reality, ergonomics affects every worker. Regardless if you work in an office, drive a snow plow, dispatch emergency vehicles, scrub floors or mow the lawn you need to understand that ergonomics can improve how you feel and how you work.
What is ergonomics and how does it relate to jobs outside the office setting?
Ergonomics is the science of designing the job to fit the worker, rather than physically forcing the worker's body to fit the job. When there is a mismatch between the physical capability of the worker and the physical demands of the job, musculoskeletal disorders (MSDs) can result.
Identifying and analyzing ergonomic hazards
The first step in developing an ergonomics program is to identify jobs or tasks that could result in MSDs. Using the list below, identify jobs with exposure to one or more risk factors.
Another step in identifying high risk jobs is to review your OSHA 300 log, workers' compensation reports, medical restrictions, and employee complaints and feedback about specific tasks that contribute to pain and lost work days. Next analyze the job in more detail. The more factors involved, the greater the possibility of developing MSDs. Consider the magnitude of exposure, duration and frequency.
- Repetition. Doing the same motion over and over again places stress on the muscles and tendons. Examples of these activities include: lifting, bending over, using tools, and moving and stacking objects. The severity depends on how often the action is repeated, the speed of the movement, and the number of muscles involved.
- Forceful exertions. Force is the amount of physical effort required to perform tasks such as lifting, carrying, pushing or pulling, or to maintain control of equipment or tools (grasping or gripping). The amount of force depends on the type of grip, the weight of the object, the duration of the activity, and the body posture.
- Body Position. Awkward postures affect the muscle groups involved in work-related physical activity. Awkward postures include repeated or prolonged reaching, twisting, bending, working or reaching overhead, kneeling, squatting, or holding fixed positions (such as sitting/driving, typing or standing). Awkward elbow posture involves extreme rotation of the forearm or repetitive work that requires the elbow to be straight with the arms extended. Awkward wrist posture is another concern with such activities as keyboarding.
- Vibration, also referred to as hand-arm vibration. Operating hand-held vibrating power tools such as chainsaws, sanders, grinders, chipping hammers, etc. can lead to nerve, muscle and joint damage.
- Contact Stress. Pressing the body against a hard or sharp edge can result in placing too much pressure on nerves, tendons and blood vessels. Examples of this include using the palm of the hand as a hammer, leaning against sharp-edged work surfaces, or gripping tool handles with sharp edges.
What can you do to prevent MSDs?
Jobs should be evaluated to identify the ergonomic risk factors associated with them. Steps should be taken to reduce repeated motions, forceful exertions, prolonged bending, lifting or working above shoulder height. When factors can be reduced or eliminated, the risk of developing problems can be reduced. Some of the strategies you might use include:
Utilizing a variety of approaches can help control these risk factors and eliminate or reduce musculoskeletal disorders in the work environment.
- Rotate workers through several jobs with different physical demands to reduce prolonged stress of the same muscles. Broaden or vary the job content to offset certain risk factors such as repetitive motion and static and awkward postures.
- Provide sufficient breaks to rest the stressed muscles. When feasible, allow self-pacing.
- When purchasing new tools, consider designs that reduce vibration, eliminate sharp edges, and incorporate handles that fit the contours of the hand and alleviate pressure points and awkward wrist positions.
- Provide adjustable work surfaces to accommodate various heights and allow for flexibility in orienting the work. Round or pad edges of work tables or containers. For vehicle drivers make sure the vehicle's seat supports the lower back. For future car purchases, consider seat design/adjustability.
- This is not a substitute for eliminating the potential problem. However, when used as an interim control measure, or used in conjunction with other types of controls, stretching will help relax muscles that have been in a static or awkward position. Don't forget this strategy for workers who drive a lot or operate equipment vehicles.
- Use mechanical assists/lifting devices where feasible, both for lifting patients and materials handling.
- Educate employees to recognize MSD signs and symptoms. Train workers on proper body mechanics, such as lifting procedures to use when a lift cannot be eliminated.
- Involve employees. Ask employees what changes they think will make a difference. They know the job or equipment better than anyone else and have ideas that may help you implement solutions.