A good chair at the appropriate height provides a solid foundation from
which to work. If our chair is too high we tend to perch, which limits
our reach and increases pressure on our thighs. It also reduces movement
and circulation in our legs. If the chair is too low, our hip angle
becomes narrower and we distribute our weight on a much smaller area of
our sit bones. Explore your chair height and feel the consequence when it
is TOO HIGH OR TOO LOW.
HOW TO EXPLORE IF YOUR CHAIR IS TOO HIGH OR TOO LOW:*
Sit comfortably on your chair and use the height lever (usually the center
or only lever on the right side beneath the chair). Raise the chair so
that your feet are hanging down without being able to support the weight
of the legs on the floor. After sitting for a moment do the following:
- Observe the sensations in your thighs. You may notice there is more
pressure, which would reduce blood and lymph circulation.
- Bring your hand up to your shoulder height and reach out forward and to
the side as far as you can. Observe how far you can reach. Notice that
you may feel unstable as if you are going to fall, which may limit your
range of movement.
- Bend your feet back and place them on the wheel supports. Again, reach
forward and to the side. Observe whether you feel more stable although
you still cannot reach very far.
Lower the chair too low so that your hips are at the same or slightly
lower level than your knees with the angle of your hips less than 90
degrees.
- Observe the sensations in your thighs. You may notice there is no
support for your legs and that all the weight is now carried on a small
area by your sit bones. Also, your lower back tends to round.
- Bring your hand up to your shoulder height and reach out forward and to
the side as far as you can. Observe how far you can reach.
Raise the chair so that your feet rest comfortably on the floor while
supporting some of the weight of your legs. The angle of your hips should
be about 90 degrees and the angle of your knees about 110 degrees.
- Observe the sensations in your thighs. You may notice there is less
pressure, which allows blood and lymph circulation, and that your legs
have more movement.
- Bring your hand up to your shoulder height and reach out forward and to
the side as far as you can go. Observe how far you can reach.
Generally, you can reach significantly further than when the chair is too
high or too low because your feet supply support base.
Keep adjusting the height of the chair until you find the most comfortable
height.
Remember, after the height of the chair is adjusted, adjust the height of
the keyboard so that you can type with your lower arms parallel to the
floor and the top of monitor at the height of your eyebrows.
If the keyboard height is not adjustable and you must raise your chair,
use footstools to support your feet. Be sure that they are wide enough so
that your legs can move.
*Adapted from a presentation by Ray Grott.
Copyright 2003 Erik Peper, Ph.D. and Katherine Hughes Gibney
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