If you suffer from chronic tension headaches, back pain or neck pain, you’re probably aware that poor posture was at least partly responsible.
However, did you know the way you sit may have had more to do with your pain than the way you stand?
If you’re like most Americans, you spend much of your day seated. That’s because your work station is probably at a computer terminal, assembly line, or desk.
Consider, too, that much of your time at home is also spent sitting – either watching T.V., surfing the Internet or reading. As a result, of the 16 hours or so you’re awake, you may well spend 12 or more of them sitting down.
Doesn’t it make sense then, that you should concentrate as much on your sitting posture as you do your standing posture?
And while standing properly – shoulders rolled back, head up, chest out – is important, the benefits of a good standing posture will be minimal if you slouch all day at your desk.
You may be one of many unfortunate workers who are forced to slouch because your work chair won’t adjust to accommodate your body, or because you don’t have your chair adjusted properly.
THE DANGERS OF IMPROPER SITTING
Three things can happen when you habitually slouch for long periods every day. They’re all bad:
* stiffness and pain in your muscles, connective tissue and joints
* restricted breathing
* postural deformities
STIFFNESS AND PAIN
Problems related to inappropriate seating are cumulative. The first noticeable symptom is usually stiffness and pain in your low back, upper back or neck. These can lead to chronic tension headaches, back aches, and muscle spasms or a restriction of circulation in your legs.
As a result of sitting slouched over all the time, other body segments begin to break down because when one part of the body is out of alignment, it’ll have an effect on the structures above and below it.
For example, if you habitually sit slumped over you’re not only at risk for back and neck pain, but also for repetitive strain injuries like carpal tunnel syndrome.
RESTRICTED BREATHING
When you’re sitting upright, you should have good tone in your lower abdominal muscles so your diaphragm is in its proper, raised position. This is important for optimal breathing.
But when you slump in your seat, your lower abdominal muscles relax and your diaphragm lowers. This forces you to breath from the upper chest instead of from the diaphragm.
As a result of decreased support from a relaxed lower abdominal wall, together with a lowering of your diaphragm, your abdominal organs are forced downward, which restricts your breathing.
POSTURAL DEFORMITIES
If you’re a woman, the resulting pressure in your pelvis from slouching all day for prolonged periods of time can be an overlooked cause of back, pelvic and menstrual pain.
And – particularly if you’re a woman – you risk skeletal deformities if your poor seating posture is not corrected.
Often, when people think of a “round-back” posture, they usually associate it with a post-menapausal woman who’s already had osteoporosis.
However, many pre-menopausal women have rounded backs that are caused by the way they sit all day.
HOW TO DETERMINE IF YOU’RE SEATED PROPERLY
Here’s a checklist you can use that will help you determine if you’re sitting properly:
* your feet are firmly on the floor, or on a foot rest, slightly in front of you
* your seat is adjusted so that your thighs are parallel to the floor, with your knees at about 90 degrees and slightly lower than your hips
* your seat allows your weight to be borne primarily on the upper half of your thighs
* your knees are shoulder width apart or closer
* your chair seat isn’t too deep (you shouldn’t be sinking in your chair)
* you’re able to sit upright, maintaining the natural curves of your back
* your back is adequately supported
* your pelvis is neutral
* your rib cage is elevated
* you can draw a straight line down through your ear, shoulder, rib cage and pelvis (check this by sitting in front of a full-length mirror, or have a co-worker analyze your sitting posture)
ERGONOMIC TIPS FOR COMPUTER USERS
If you sit at a computer terminal all day, there are other factors you need to consider:
* you should be sitting directly in front of your keyboard and computer screen
* your monitor should be between 18 – 24 inches from your eyes, and you should have to look slightly down to see it
* you should use a work surface that allows your elbows to maintain about a 90 degree angle
* you should keep your shoulders relaxed; don’t slump forward
* you should relax your wrists and keep them in a neutral position; don’t flex them up or down
* while typing, keep your shoulders relaxed and your elbows loose at your side
* take breaks
When doing extensive computer work, it’s important to take brief breaks to stretch and walk around every 30 minutes or so. Alternate between work activities that utilize different muscle groups.
Make sure to give your eyes a periodic break, too. For example, blink frequently, close them momentarily and gaze at different objects.
THE DIFFERENT KINDS OF CHAIRS
CASTER WHEELS
In most work environments, and in nearly all offices, chairs are mounted on caster wheels to allow you to move from task to task easily. These wheels are usually mounted on a five-point base.
STATIONARY BASE
In some industrial settings, a chair with a stationary base is more common because of safety issues. Such chairs are often found in laboratories because the floors tend to be hard and smooth, making caster wheel chairs risky.
Stationary chairs are the norm in assembly lines because they’re more stable.
BENCH CHAIR
Bench chairs are often used in small parts assembly areas in manufacturing, as well as for other jobs that require manual dexterity. Bench chairs are higher than typical office chairs and usually offer footrests for stability and comfort.
SIT-TO-STAND CHAIRS
Sit-to-stand chairs are best if you move from a seated to a standing position often during your shift (if you work as a receptionist or assembly line worker, a sit-to-stand chair would be a good choice).
These chairs usually don’t have a backrest. the seat is angled downward, allowing you to lean comfortably in a half-standing position.
OTHER FACTORS THAT AFFECT ERGONOMICS
BACKRESTS
The backrest of your chair should stabilize your pelvis and elevate your rib cage by supporting your lower back.
If it doesn’t support your lower back properly, then it will sink into the backrest. A backrest that’s too soft, inclined, and/or concave causes this to happen.
These faults result in a backrest that supports the wrong areas, which reinforces slumping.
FOOTRESTS
If your work surface is too high to allow you to place your feet on the floor, then you need a footrest. The footrest should be large enough to allow you some movement during the day. It should also be adjustable to accommodate your height and leg length.
FIVE-POINT BASE
A five-point base offers you maximum stability and can usually be found with any type of chair.
HOW TO PICK THE RIGHT WORK CHAIR FOR YOUR BODY TYPE
When shopping for a work chair, you must realize that one size doesn’t fit everyone. You must consider what you do at your chair all day, as well as take into account your physical size.
Generally speaking, you want a chair that provides appropriate support to your back, legs, buttocks and arms.
Here are the various components of a work chair and what to look for in them:
THE BASE
You want a chair that has a five-pedistal (point) base, regardless of whether you need casters (wheels). If you choose a chair with less than five pedestals, you’re sacrificing stability and safety (chairs with four casters can tip over more easily).
Make sure the base allows the chair to swivel easily.
ARMRESTS
Keep in mind that armrests should only be used while reading or resting between typing sessions, NOT while actually typing or using your mouse. Depending on how you spend your time in the chair, you might not even need armrests.
If you do get a chair with armrests, make sure they’re adjustable, broad, cushioned and comfortable. While seated, you should be able to independently adjust the height of the armrests and move them closer together or further apart.
THE SEAT PAN
The part of the chair that you sit in (the seat pan) should allow even weight distribution and comfortable support. Pay attention to the width and depth of the seat pan – it should be wide enough to give you at least one inch of unused space on both sides of your thighs and hips.
It should also be deep enough to support your thighs comfortably and not put pressure behind your knees (that’s bad for circulation).
The seat pan should feel comfortable even after sitting for an hour or more. Insufficient cushioning and poor contouring can cause hip and back fatigue, so ensure that the padding is of high enough quality to resist becoming permanently deformed.
CHAIR HEIGHT
You should buy a chair that allows you to adjust its height easily. The best chairs have a device that permits you to adjust the height of the seat pan while you’re seated (a chair with a spinning mechanical height adjustment mechanism is okay, too).
Either way, make sure the adjusters are within easy reach while you’re seated – you shouldn’t have to get up to change the height of your chair.
If more than one person will be using the chair, make sure the range of heights will accommodate all users. You should be able to adjust the height of the seat pan so that the fronts of your knees are level, or slightly below level, with your feet firmly on the ground or on a footrest.
LUMBAR SUPPORT
A good lumbar support (the part of the chair that supports your lower back) is essential. Many chairs have cushioned lumbar supports that can be adjusted up and down and forward or backward. That’s what you want, as these supports will better fit your shape.
The ability to adjust your chair is especially important if more than one person will use the chair.
A fixed-height lumbar support might be okay if you’re the only user of the chair and it feels comfortable when you sit back against it.
When sitting against the lumbar support, make sure there’s sufficient room for your hips and that you aren’t being forced so far forward in the chair that you lose thigh support.
BACK SUPPORT
The back support should recline to allow you to sit back at more than 90 degrees. The best chairs allow your back to move and also track your back as you move back and forth.
Try to avoid locking a back support in one position. Look for a support that’s sufficiently broad and doesn’t put pressure on the side of your back. The support should also be tall enough to provide good support to the middle of your back – at least up to your shoulder blades.
HEADREST
If you like to recline in your chair to read, talk on the phone or relax, look for a chair with a high back and good neck and head rest.
PRICE
Good chairs are coming down in price, but they can still be costly. You can get a good chair for between $300 and $500.
(Remember this – you get what you pay for)
While $300 to $500 (or more) may seem like a lot of money for a chair, if you’re among the millions of people who spend most of their workdays sitting, a high-quality, comfortable chair is a wise investment.