Adjusting Your Equipment to Fit You

The human body was designed to move. One of the most important aspects of a good sitting habit is movement. Standing up from your chair and frequently adjusting your sitting posture can be one of the best methods to guard against injury and fatigue. The best chair design in the world will not force good posture or prevent the need for the human body to move.

There are three factors that will directly influence your sitting posture:

Make sure that your work area is designed so that your eyes can comfortably see what they need to see, you can comfortably reach what you need, and your chair gives you an appropriate range of comfortable postures. You will find that different tasks require different postures. Adjust your chair and posture to accommodate multiple positions within a comfortable range rather than sitting in a single "correct" position. The following are some guidelines to evaluate proper chair adjustment and fit.

Adjust the height
Your feet should rest comfortably on the floor or, if necessary, should be supported by a footrest. For most people the knees should be at a level equal to or slightly lower than the hips. Adjust the chair height to attain a natural inward curve of the spine and optimize the comfort of your lower back. If the chair is too low, your lower back will flatten or round out. If the chair is too high, your feet, and therefore your back, are unsupported. Circulation to the lower leg can also be compromised if the chair is too high.

Check the length of the seat pan
There should be 2-3 inches between the back of your leg and the seat of the chair. This will allow for a natural bend in your knees. If the seat pan is too short, it can create pressure points and discomfort in the back of the thigh. If the seat pan is too long, you will not be able to sit back in the chair. Some chairs have adjustments that shorten or lengthen the seat pan if necessary. Lumbar pillows can also be used as a method to improve the fit of a seat pan that is too long.

Adjust the seat pan and backrest angles
If your chair has seat pan and backrest angle adjustment, adjust the angle of each to support your work activities. The chair should support an upright position for keyboard activities. If your chair rocks or reclines, consider adjusting the tension to support upright postures for computer and desktop activities.

Adjust the lumbar support
The curve of the backrest should support the natural curve of your back. You should not feel too arched, nor should you feel unsupported. If your chair does not provide sufficient lumbar support, you might be able to use a lumbar pillow or towel roll to improve the fit.

Adjust the armrests
Armrests, if you have them, should adjust to match your elbow height when your elbows are relaxed at your sides. If your armrests are too long or too high, they will interfere with proper keyboarding position. Your armrests should allow you to keep your elbows relaxed at your sides and should not interfere with access to the work surface If your armrests do not adjust for proper fit, consider removing them.