Ergonomic.com.hk - Ergonomic Workplace Consultation in Hong Kong

There are many risk factors for repetitive strain injury (RSI). Some are well-known, such as spending long hours working with a mouse or sitting in a poorly configured workstation. Others are not readily apparent. For example, having long fingernails leads you to type with flat rather than curved fingers. But if you don't know the major risk factors then you add another: ignorance. You can't take preventive measures if you aren't aware of the dangers.

Sitting in one place for long periods is a risk because it slows blood circulation, which is needed to remove the waste products of simple muscle activity, such as typing and using the mouse. Continuously holding your elbows bent in the palms-down position strains the nerves and muscles of the arms and upper body. Poor sitting habits compound the problem. For example, leaning on your elbow can compress the nerve, or sitting on one foot can impede circulation in your legs.

Making the same movements again and again, such as typing numbers into a spreadsheet or circling a mouse or trackball, tires the muscles. You can be injured by as little as two hours of mousing per day, and are in the danger zone at four hours per day. Working for extended periods without taking breaks does not allow the muscles time to recover from the exertion.

Staring at the monitor without doing much at all--sometimes referred to as static loading--can also be injurious. Web surfing is a perfect example. You might be gripping a mouse and slouching in your seat. Your head might be falling forward and your shoulders slumping, which strains muscles of the upper body from neck to fingertips. (Sitting with your feet up on the desk and the keyboard in your lap is not a great idea, either.)

Faulty technique includes resting your wrists, forearms, or elbows on the desk or armrest as you type or winging your elbows away from your body. Cradling the telephone between your ear and shoulder with your head cocked to the side is also a bad habit. And you shouldn't pound the keys or grip the mouse, twisting your wrists from side to side or up and down.

Working in awkward positions not only makes people grumpy, it leads to injury because the muscles become strained and fatigued. Awkward positions can be cultivated by working in a cubicle that's too small or sitting on an uncomfortable chair. Many monitors are too high, too low, or off to one side. Keyboards on desktops are often too high, but on your lap they are too low. Mice are often too far away to be reached without straining.

People who have strong work ethics may ignore their own needs to get ahead in their careers or because they feel obliged to give 110 percent. Others work on cyclical deadlines, where weekly, monthly, or quarterly crunch times result in unusually long hours at the computer. RSI can be a "nice guy's disease," felling people who habitually volunteer to take on extra work or can't say no.

People have varying degrees of awareness about pain and comfort or how they move, sit, and stand. Some people zone out at the computer, concentrating so much that they forget about their posture or movements. Becoming sensitive to these matters helps you become aware of symptoms and avoid injury or reinjury

Your hobbies.
The total number of hours that you use your hands adds up. So don't forget to count off-hours pursuits, such as playing musical instruments, video games, or racquet sports; gardening; bowling; or working at needle crafts or carpentry. You may wish to avoid the traumas of volleyball, hand drumming, and similar hand-intensive activities altogether.
Built for strain.
A number of anatomical variations or medical conditions can predispose you to RSI. If your humerus (the bone of the upper arm) is very long, you will not be able to bring your hands to the keyboard without pushing your elbows out--unless you work standing up. Obesity, poor physical conditioning, arthritis, hormonal changes, thyroid disease, and other medical conditions can all enter into the equation.

If these risk factors resonate with you, take measures to prevent injury now before you start having problems. If you develop RSI, your ability to work will be greatly diminished because by repeating the offending activity or merely performing daily tasks, you can reinjure yourself. Good ways to decrease your risk of injury include reducing the amount of time you use a computer; taking regular, frequent breaks (at least every 20 minutes); avoiding sitting for long periods; and stretching and strengthening the muscles of your upper body, especially the back, three to five times a week.