The ABCs of Computer Comfort
We have become a nation of professional sitters. In offices all around America, people are sitting behind computers in really bad posture positions - necks craning forward, slumping upper backs, rounded shoulders.
Sitting for a long time is a major cause of back discomfort: it puts continuous pressure on the muscles and disks of the lower back. You may think your back muscles get a rest when you sit. Actually, they're working very hard to hold you upright. Sitting puts 40% more pressure on the lower back disks than standing does.
You can increase your awareness of your posture by enlisting the help of a friend at work. Ask him or her to let you know when your posture is bad. Do this for each other.
Sitting is particularly hard on the lower back if you sit with your lower back rounded out (called forward flexion). Make sure you sit with your pelvis neutral: The top of the pelvic bones (iliac crests) should line up with the pubic bones. This is much less stressful for your lower back. Leaning over a desk and looking up and down from a keyboard to a computer screen puts pressure on the neck and upper back too. By stopping the slouch, supporting your back properly, and avoiding the head-forward position, you will be able to work more comfortably and productively.
Replacing or modifying your office furniture is a good start. Fortunately, more manufacturers are producing furniture and accessories with good posture in mind. Ergonomically designed furniture can help reduce the user's fatigue and discomfort, and help increase productivity. Keep in mind that a piece of furniture is ergonomically correct for you only if it fits your particular body.
In any case, furniture alone can't help your posture. You also have to become more aware of how to sit, and you need to take little breaks during the day.
Setting Up a Desktop Computer Workstation
Try to make as many of the following adjustments to your desk and chair as possible. They will take away most of the causes of back and neck discomfort.
- Your monitor should be about twelve to twenty-four inches away from your eyes.
- Your eyes should be level with top of the monitor. This will let your eyes fall comfortably on the screen. Your head will be balanced over your spine, not tilted forward or backward. If your screen it too low, put it on a computer base or on books. If your screen is too high, lower it.
- The monitor should be placed directly in front of you - not to the left or right where you have to twist your spine or neck to see it.
- Using a document holder can eliminate uncomfortable neck twisting. Use the in-line document holder that sits between the keyboard and tray. Put your work at eye level without having to twist your neck or spine. You want to tilt the angle of your work - not angle of your head on your neck.
Bifocals/Progressive Lens Wearers
- Your chair should recline to 110 degrees instead of 90 degrees.
- Slightly tilt your monitor back by placing something under the front edge of the monitor. This should allow you to view the screen comfortably without craning your neck forward or tilting your head back too far.
- The perfect keyboard level for you is at elbow level, with your forearms in a ninety-degree angle with your upper arm or slightly lower with the keyboard base gently sloped away from the user. This position allows the back, neck, shoulders, and arms to relax more. If your keyboard level is too low, place blocks under the legs of the desk. If it's too high, raise your chair seat and use a footrest.
Using a Mouse
- Your mouse needs to be as close to you as possible.
- When using it, your elbow should be at a ninety-degree angle to your forearm.
- Keep upper arm relaxed and close to your body.
- Check office supply stores for mouse pads that attach to the arm of your chair. Over-reaching for a mouse causes the spine to twist slightly.
- The ideal computer chair has adjustable armrests that support your arms at elbow level. Both the width and height of the rests should be adjustable. By supporting your elbows on an armrest, 25% of the pressure load is taken off the lower back disks. Armrests also take the burden of holding up the arms from the mid- and upper back muscles.
- The ideal chair will support the width and length of your back. At the very least, the chair back should reach to your shoulder blades.
- The back of the chair, the chair rest, should be fairly straight; at a 90- to 110-degree angle to the seat.
- When you sit, make sure you slide your bottom all the way to the back of the chair seat. Your buttocks and the middle of your back should make contact with the backrest.
- The chair seat should be padded with rounded edges and slightly tilted. The back of the seat should be slightly lower than the front, so the buttocks can be placed against the back of the chair and the knees can be slightly higher than the hips.
- Your knees should extend no more than a few inches from the edge of the seat.
- The chair seat should be long enough to support the whole length of your thighs. That way, the weight of your body is evenly distributed over your buttocks and the full length of your thighs. If the seat is not long enough to support the length of your thighs, you'll end up crossing your legs, which causes imbalances in the hips and lower back. Sitting with your legs crossed also can contribute to varicose veins and poor circulation.
- Your feet should rest flat on the floor. Adjust the height of the seat or get a footrest. A telephone book works in a pinch.
- Your chair should swivel and be on casters so you can adjust your reach and line of vision without twisting, bending, or leaning forward.
Retrofitting a Chair
If you can't buy a new chair, try these inexpensive ways to adjust the seat height, back support, and armrests.
- If the seat is too low and armrests are too high, place a cushion on the seat to raise your body. Use a telephone book or box as a stool for your feet.
- If the chair depth was made for a person with longer legs, place a cushion between the chair back and your body.
- If you don't have armrests, try placing a box on your lap and resting your elbows on it.
- To prevent your lower back from slouching backward, place a small lumbar pillow behind you to remind you to sit with your pelvis in neutral.
Sitting Too Much?
Sitting too long without moving around is a major contributor to back pain in office workers. Here are some ways you can sit less and stand more.
- Stand when you're talking on the phone.
- Walk over to a colleague's desk instead of phoning or emailing.
- Position equipment so you'll have to stand and walk; for example, put the printer or fax across the room.
- To increase circulation, clench and release your buttock muscles.
- Shift positions often to change the load on your spine.
Avoiding Carpal Tunnel Syndrome
Flexing your wrists while doing repetitive hand and finger movements, such as typing or working a cash register, places you at higher risk for developing carpal tunnel syndrome: numbness, tingling, burning, or pain in the middle and index fingers and thumb (and sometimes all the fingers). Eventually, your hand grip may weaken. Carpal tunnel syndrome is increasingly common among office workers. You can reduce your risk by modifying your workstation and changing the way you use your hands.
Hand and finger movements repeated over and over for a long time, especially when the wrists are lower than the fingers, cause inflammation around the median nerve, which runs through a narrow tunnel of bone and ligament in the middle of the wrist. Since bones and ligaments have no give, this puts pressure on the nerve and causes the symptoms.
If you have any of the above-mentioned symptoms, see your doctor for diagnosis and treatment. Early intervention can help prevent and minimize symptoms. Stop the problem before it becomes severe.
If you work at a keyboard, and especially if it causes you discomfort, also try to make the following changes at work:
- Your keyboard should be at elbow level or a little lower. If the keyboard base slopes gently away from you, your hands will be a little lower than your wrists. Research from Cornell University shows this position puts less stress on nerves and soft tissue. Make sure your wrists are not flexed with the fingers higher than the wrists. Bending the wrist this way narrows the tunnel through which the median nerve passes, so it can actually contribute to carpel tunnel syndrome or even worsen the problem.
- Rest your hands periodically throughout the day.
- If you can, rotate work activities so you don't spend hours at a time at the keyboard.
- Exercises that strengthen the hand and arm muscles may help. When these muscles are weak, there's a tendency to compensate with poor wrist position.
- If you are experiencing the symptoms of carpal tunnel syndrome, a physical therapist can design splints for you to wear while you work, which protect your wrists and keeps them in a neutral position. The splints will be specific to the kind of work you do. You may want to wear a wrist splint at night. It will keep your wrist in a neutral position so symptoms don't wake you. It may also reduce your symptoms during the daytime.
Laptops are fast becoming the most popular way to do computer work. They can be great for short periods of work. Laptops are convenient, but can be extremely hard on your back and neck. Using a laptop is always a trade-off between poor head and neck posture and poor hand and wrist posture. Because of their design, you will either get the screen level correct for you body or the keyboard level correct - never both.
If you spend hours on your laptop, you may consider purchasing the following:
- an external monitor,
- an external keyboard, preferably with a negative tilt,
- a docking station.
Occasional users should:
- Find a chair that is comfortable and that reclines back 110 degrees.
- Position laptop in your lap for the most neutral wrist posture.
- Angle the screen to be seen with the least amount of neck deviation.
Full-time users should:
- Position laptop on desk in front of you so you can see the screen without bending your neck. You may need to elevate the laptop off the desk using a monitor pedestal.
- Separate the keyboard and mouse.
- Connect a separate keyboard and mouse to back of laptop. A negative tilt keyboard is preferable to ensure a neutral wrist posture. Use a mouse platform to raise the mouse off the desk.
For a Desk Without a Computer
The same features of a good chair apply if you work at a desk without a computer. The top of the desk should be at elbow level.
Angling the surface of your workstation prevents you from having to lean over your work. Constantly leaning the head forward over a desk causes much back and neck misery. Office supply stores sell inexpensive drafting boards that can be placed on top of a desk. You can also prop up a clipboard. Adjust the surface so you are looking straight ahead rather than down. A raised work surface will enable you to sit and work with your back and head straight and balanced. You could also tilt the desk surface toward you by putting books or boards under the back legs of the desk. Propping up your work surface, however you can, will allow you to work with your head directly over your spine.
The way you talk on the phone can cause posture problems, too. Don't clench your phone receiver between your ear and shoulder. If you need to keep your hands free, get a wireless headset.
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