Thursday, March 15, 2012


Computer related injuries:

Long periods of working at a computer can increase the chance of developing an injury. Muscle and joint pain, overuse injuries of the upper limbs and eyestrain can result from inappropriate computer use. The risks can be reduced or eliminated with proper work space design, improved posture and good working habits 
What is the best position for the monitor at my workstation?
Many make the mistake of putting the monitor, the keyboard, or both off to one side on a desk. If you perform more than a few minutes of keyboarding a day, the keyboard and monitor should be placed directly in front of your normal sitting position. The screen should be 18-30 inches from your eyes, or about an arm's length.

Carpal tunnel syndrome: Typing at the keyboard or using the mouse for hours and hours is horrible for your joints. This can lead to Carpal tunnel syndrome which causes pain, numbness and tingling sensation in the arm (mostly in the thumb and index fingers). Carpal tunnel is a narrow passageway on the palm side of your wrist that protects a main nerve to your hand and nine tendons that bend your fingers. The compression of the median nerve in this tunnel causes the signs and symptoms associated with carpal tunnel syndrome. 

Repetitive Stress Injury symptoms when found, people should seek medical attention as early as possible. Measures that can be adopted to avoid Repetitive Stress Injury at an individual level include:
Position: The recommended position to sit in front of a computer is semi-reclined with the forearms resting in a cradle or on an extension of the keyboard support to prevent Repetitive Stress Injury.
There should be ample support for the back. The hands should be free and point in the direction of the forearms. The feet should rest on the ground or feet support. The distance of the monitor should be 18 inches or more and at a slightly lower level than the eye level. Using these measures Repetitive Stress Injury caused out of position can be avoided.

Hydration: The Repetitive Stress Injury can be prevented by drinking adequate fluids to keep the tendons and soft- tissues soft.

Shortcuts: Using keyboard shortcuts and less of mouse is the most effective preventive method to avoid Repetitive Stress I rest.

Posture related injuries:

Back and neck pain, headaches, and shoulder and arm pain are common computer-related injuries. Such muscle and joint problems can be caused or made worse by poor workstation design, bad posture and sitting for extended periods of time due to  reduction in circulation to the muscles, bones, tendons and ligaments and can result in stiffness and pain. 
What other accessories and placements are important?
Frequently used items should be within arm's reach from your keyboarding position. A document holder should be at the same height and distance as the screen so that your eyes don't need to change focus frequently.Remember that many RSIs begin with nerve insult in the neck and shoulders.

Prevention of muscle and joint injuries:

  • Use an adjustable desk designed for use with computers
  • Position the monitor so that it is either at eye level or slightly lower
  • Position your keyboard at a height that allows your elbows to rest comfortably at your side
  • Forearms should be roughly parallel with the floor and level with your keyboard
  • Adjust your chair so that your feet rest flat on the floor
  • Use a footstool if your feet do not rest on the floor
  • Switch to an ergonomic chair, which helps your spine to naturally hold its curve while sitting
  • Use an ergonomic keyboard to offer your hands and wrists a more natural holding position
  • Take frequent short breaks and go for a walk or perform stretching exercises at your desk or Stand often
Neck and shoulder pain: One of the main causes of neck pain in middle-aged people today is from straining their neck to see and work on a computer screen. Excessive computer usage also leads to stiff shoulders. All this results from poor seating posture and poor organization of work equipments on the desk. 

Prevention of upper limb related injuries:

Muscles and tendons can become painful with repetitive movements and awkward postures and symptoms of overuse injuries in the upper limbs include pain, swelling, and stiffness of the joints, weakness and numbness
  • Keep your mouse at the same height as your correctly positioned keyboard
  • Position the mouse as close as possible to the side of the keyboard
  • Use your whole arm, not just your wrist, when using the mouse
  • Type lightly and gently
  • Mix your tasks to avoid long, uninterrupted stretches of typing
  • Remove the hands from the keyboard when not actively typing, to allow the arms to relax

Eye strain: Eye strain is a common health hazard associated with prolonged exposure to computer screens. Constantly staring at the computer screen can cause dry or watery eyes because of your tendency to blink less. Excessive strain on eyes - Computer Vision Syndrome (CVS) - can lead to itchy or burning eyes, blurred or double vision and headaches.

Prevention of Eye strain:

Focusing your eyes at the same distance point for extended periods of time causes fatigue
  • Make sure your primary light source is not shining into your face or directly onto the monitor
  • Tilt the monitor slightly to eliminate reflections or glare
  • Make sure your computer screen is not too close to your face
  • Position the screen so that it is either at eye level or slightly lower
  • Reduce the contrast and brightness of your screen by adjusting the controls on the monitor
  • Frequently look away from the screen and focus on faraway objects
  • Have regular eye examinations to check that blurring, headaches and other associated problems are not caused by any underlying disorders
Is there an optimum screen brightness and color scheme to help prevent eye strain?
Black characters against a light gray background are often easiest on the eyes for long periods. Its suggested that contrast and brightness should be adjusted to create the brightest screen without blurring.

What is the best room lighting to help reduce eye strain?
A mixture of fluorescent and incandescent light is usually most pleasing. The most important aspect of lighting is to reduce glare and bright reflections from your screen, nearby glass, or shiny surfaces. Since light conditions change during the day this may require several adjustments while working. If you smoke while keyboarding, be sure to clean your screen frequently, as water vapor and smoke form a potent film.
Is there an optimum height for my monitor and mouse?
Yes. The top of the monitor should be at eye level because the eyes are at their most comfortable position straight ahead but slightly downward. This is why reading lenses in bifocal glasses are placed just below the horizontal plane. This posture also makes it easiest to balance your head above your shoulders with the least muscular effort.
On the topic of eye correction, make sure your eyes have been examined recently and that if you do need correction your optometrist should know about the amount of your monitor use and its distance from your eyes. A correction just for monitor use may be necessary. Be sure to look away from your screen at least every 30 minutes and focus on something over 20 feet away.
Poor mouse operations can create RSI. At many work stations it is common to see the keyboard in proper position just above the knees, but the mouse is on a higher and more forward countertop. Mouse position should be on the same level as the keyboard so that mouse use does not create a twisted or reaching posture. A keyboard tray with a mouse shelf extension is one easy and inexpensive solution to this problem.

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. 
Static loading. 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.  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. 
Awareness of discomfort. 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.
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. 
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.


1 comment:

Anonymous said...

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