ERGONOMICS – ERGOWHAT?

The mysterious world of ergonomics.  What exactly does it mean?  Is it like feng shui?  Is it doing exercises during the work day?  Is it moving furniture? 

None of these explanations is exactly correct, though some play a part in defining ergonomics.  Ergonomics is not a thing, per se, but is actually a process of fitting the workplace to the worker.  Years ago, people might have said, “I must be getting old, I have an ache in my shoulder.”  Today, we know it is possible that the way we perform our work tasks and the setup of our workstation could be contributing factors to our aches.  For example, people know about carpal tunnel, but are surprised to learn it can be a symptom of poor ergonomics. 

The work we do is made up of a combination of tasks.  Each task may have a number of steps involved to complete the activity.  How a person uses his or her body to perform the tasks can determine the ergonomic risk factors involved. 

Cumulative trauma disorder (CTD) is a category of diagnoses involving many different body systems, including muscles, tendons and nerves.  CTDs can be caused or aggravated by various risk factors - either alone or by a combination of the following:

• Repetitive Motion
• Forceful Exertions
• Weak Posture

REPETITIVE MOTION

Repetitive motion means prolonged, repeated use of a muscle or muscle group. Without a sufficient rest cycle, the muscle can fatigue and may eventually become damaged. It is key to remember our bodies were not designed to function for long periods making the same motions (like a machine). You may notice that while doing a task that is repetitious, you naturally take very short "rest pauses". Those pauses allow blood to flow into the muscles, tendons and ligaments to refresh the cells and carry away waste products. It is natural to need a rest pause (lasting only 1-3 minutes) every 15-30 minutes. An example of a rest pause could be stopping briefly while typing to shrug your shoulders and look away from the screen briefly. Another example could be arranging or grouping tasks in order to leave the desk area temporarily to make copies or file, which will use different muscle groups than those used in typing.

FORCEFUL EXERTIONS

Forceful exertions can cause damage to tendons and muscles if performed continuously, excessive force is required, or the movements are jerky. Sustained or static forceful muscle contractions can restrict blood flow to the area, and over time can result in damage to the local nerve and muscle tissue.

WEAK POSTURE

Weak postures can occur whenever the body is out of neutral position. Neutral position means the body is in alignment, using what you may remember from school described as "good posture." The head, neck and shoulders are relaxed and in natural alignment. When viewed from the side, the ears are directly over the shoulders (not leaning forward), the back is in its natural alignment with shoulders and elbows in a relatively straight line with hips, knees and ankles. Viewed from the front, shoulders are in a relaxed position, arms at sides, and knees and feet are in alignment as well. There is a risk of injury when muscles and joints are not in a neutral position.

The likelihood of problems from CTD is stronger when any two of these risk factors are excessive. For example, typing is very repetitive for the wrists, hands and fingers. If a person also strikes the keys hard (force) while typing, or if they use a wrist posture out of neutral alignment (weak posture), they could be at risk for developing problems. Using a computer mouse is repetitive for the fingers and thumb, and if done with your arm extended and elbow held away from the body (weak posture) you could strain your upper back and neck because you are supporting your whole arm with your upper back muscles. Your shoulder and elbow are not in neutral position, which could mean you are at risk for discomfort.

The key to preventing CTDs is to identify the cause. Once you have identified the risk factors contributing to the problem, you can find a solution. A good method to finding a solution is to brainstorm with a group of people, with some having training in ergonomics principles. The group should include a cross-section representing management, supervision, employees, health and safety, human resources and maintenance.

ERGONOMIC TIPS

Here are some principles of ergonomics to help you enhance your workplace and minimize ergonomic risk factors:

• Keep frequently used items within easy reach
• Keep work at proper heights to avoid reaching, especially overhead
• Maintain good posture (neutral position)
• Be aware of activities requiring high force
• Simplify motions
• Take a rest pause every 15-30 minutes
• Understand the task and motions required
• Facilitate variety in the tasks, to allow use of different muscle groups and rest pauses
• Design and install an ergonomic workstation

All of these tips will help minimize the risk of developing CTD, and most of them are not expensive to implement. An ergonomic workstation does not necessarily mean buying new desks and chairs for all the employees. It may be as simple as re-arranging things on a desk to make them more accessible or adjusting the chair and computer screen you already have. The important thing is to set up a workstation to minimize risk factors as much as possible. You will have to encourage employees to try a different way of doing their tasks, and it may feel awkward to them for a while. People frequently develop habits and adaptations when performing their work tasks, and they may have to "un-learn" some of those habits in order to be more comfortable with ergonomically correct actions.

If you have questions or want to learn more about workplace ergonomics, please contact DEG at http://www.dohertyhro.com/contact.html. Resources can also be found at www.osha.gov/SLTC/ergonomics/ and www.dir.ca.gov/dosh/dosh_publications/EasErg2.pdf.