Once the workstation has been situated, then the user can adjust the office chair according to his or her physical proportions. Here are the most important guidelines - distilled into a quick checklist - to help make sure that the office chair and work area are as comfortable as possible and will cause the least amount of stress to the spine:
1. Elbow measure
First, begin by sitting comfortably as close as possible to your desk so that your upper arms are parallel to your spine. Rest your hands on your work surface (e.g. desktop, computer keyboard). If your elbows are not at a 90-degree angle, adjust your office chair height either up or down.
2. Thigh measure
Check that you can easily slide your fingers under your thigh at the leading edge of the office chair. If it is too tight, you need to prop your feet up with an adjustable footrest. If you are unusually tall and there is more than a finger width between your thigh and the chair, you need to raise the desk or work surface so that you can raise the height of your office chair.
3. Calf measure
With your bottom pushed against the chair back, try to pass your clenched fist between the back of your calf and the front of your office chair. If you can’t do that easily, then the office chair is too deep. You will need to adjust the backrest forward, insert a low back support (such as a lumbar support cushion, a pillow or rolled up towel), or get a new office chair.
4. Low back support
Your bottom should be pressed against the back of your chair, and there should be a cushion that causes your lower back to arch slightly so that you don’t slump forward or slouch down in the chair as you tire over time. This low back support in the office chair is essential to minimize the load (strain) on your back. Never slump or slouch forward in the office chair, as that places extra stress on the structures in the low back, and in particular, on the lumbar discs.
5. Resting eye level
Close your eyes while sitting comfortably with your head facing forward. Slowly open your eyes. Your gaze should be aimed at the center of your computer screen. If your computer screen is higher or lower than your gaze, you need to either raise or lower it to reduce strain on the upper spine.
6. Armrest
Adjust the armrest of the office chair so that it just slightly lifts your arms at the shoulders. Use of an armrest on your office chair is important to take some of the strain off your upper spine and shoulders, and it should make you less likely to slouch forward in your chair.
Stay Active To Reduce Back Pain in the Office
No matter how comfortable one is in an office chair, prolonged static posture is not good for the back and is a common contributor to back problems and muscle strain.
To avoid keeping the back in one position for a long period, remember to stand, stretch and walk for at least a minute or two every half hour. Even a quick stretch or some minimal movement – such as walking to the water cooler or bathroom - will help.
A twenty minute walk will help even more, promoting healthy blood flow that brings important nutrients to all the spinal structures.
In general, moving about and stretching on a regular basis throughout the day will help keep avoid the joints, ligaments, muscles, and tendons loose, which in turn promotes an overall feeling of comfort, relaxation, and ability to focus productively.
What Features Should a Good Ergonomic Office Chair Possess?
In order to choose a right ergonomic chair that suits your body, there are a number of things an ergonomic chair to consider:-
• Seat height. Office chair seat height should be easily adjustable. A pneumatic adjustment lever is the easiest way to do this. A seat height that ranges from about 16 to 21 inches off the floor should work for most people. This allows the user to have his or her feet flat on the floor, with thighs horizontal and arms even with the height of the desk.
• Seat height. Office chair seat height should be easily adjustable. A pneumatic adjustment lever is the easiest way to do this. A seat height that ranges from about 16 to 21 inches off the floor should work for most people. This allows the user to have his or her feet flat on the floor, with thighs horizontal and arms even with the height of the desk.
• Seat width and depth. The seat should have enough width and depth to support any user comfortably. Usually 17-20 inches wide is the standard. The depth (from front to back of the seat) needs to be enough so that the user can sit with his or her back against the backrest of the ergonomic office chair while leaving approximately 2 to 4 inches between the back of the knees and the seat of the chair. The forward or backward tilt of the seat should be adjustable.
• Lumbar support. Lower back support in an ergonomic chair is very important. The lumbar spine has an inward curve, and sitting for long periods without support for this curve tends to lead to slouching (which flattens the natural curve) and strains the structures in the lower spine. An ergonomic chair should have a lumbar adjustment (both height and depth) so each user can get the proper fit to support the inward curve of the lower back.
• Backrest. The backrest of an ergonomic office chair should be 12 to 19 inches wide. If the backrest is separate from the seat, it should be adjustable in height and angle. It should be able to support the natural curve of the spine, again with special attention paid to proper support of the lumbar region. If the office chair has the seat and backrest together as one piece, the backrest should be adjustable in forward and back angles, with a locking mechanism to secure it from going too far backward once the user has determined the appropriate angle.
• Seat material. The material on the office chair seat and back should have enough padding to be comfortable to sit on for extended periods of time. Having a cloth fabric that breathes is preferable to a harder surface.
• Armrests. Office chair armrests should be adjustable. They should allow the user's arms to rest comfortably and shoulders to be relaxed. The elbows and lower arms should rest lightly, and the forearm should not be on the armrest while typing.
• Swivel. Any conventional style or ergonomic chair should easily rotate so the user can reach different areas of his or her desk without straining.
Alternatives to Traditional Office Chairs
While a traditional office chair is designed to provide complete support, these alternatives help promote good posture without a back support. They also require more active use of one's muscles (e.g. for balance and to sit upright). If you have an injured back or other health problems, it is advisable to first talk with your doctor prior to using one of these types of chairs.
There is no single type of office chair that is optimal for all patients, and people should determine their individual preference for comfort while following the guidelines explained in this article to promote good posture and back support while sitting in an office chair.
US 18069 
GB 14693 
CA 11735 
AU 9463 
IE 7149 
NZ 2435 
BR 1089 
SG 975 
