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ANSI-Recommended Seating:
1) Seat height should range from 16” to 20.5”. This refers to how high the chair seat should be with a
person’s weight pressing on the cushions.
2) Seat depth for chairs with rectangular cushions or chairs made of hard materials should range from 15” to
17”. Seat depth refers to the distance from the front edge to the back edge of the seat cushion. Seat depth
can be greater if the front edge of the seat is soft or curved.
3) Seat width should be at least 18.2” measured across the middle of the seat. Seat width refers to the side-
to- side distance across the seat cushion.
4) Distance between armrests should be at least 18.2” measured between the inner edges of the armrests.
5) The backrest should be at least 12” wide in the lower back area.
Adjusting your work surface
The proper height of the work surface is related to the clearance you have beneath it to accommodate your
legs while in a seated position.
1) Pull up to the work surface while seated. With your feet flat on the floor, adjust the height of your work
surface so that your knees do not bump the edge of the work surface or keyboard support tray (when the
tray is in its working position). The tops of your thighs should not touch the underside of the work surface.
2) When pulled up to the work surface, your feet or knees should not bump against the back of the work
surface or wall supporting the work surface.
3) Swivel to grasp something within easy reach on your work surface. You need enough clearance beneath
your work surface to move freely. Your knees should not bump against anything under the work surface.
If the height of the work surface causes your shoulders to be raised up or hunched, consider lowering your
work surface. If you must hunch over your work surface, consider raising it so that you can work in a
comfortable, upright position. Check the height of your work surface against the ANSI recommendations:
1) Knee space should measure at least 20” from side to side under the work surface; 24” is preferred.
2) The underside of the work surface or keyboard tray should be higher than your knees. If your work
surface cannot be raised or lowered, the clearance under the work surface should be at least 26.2”.
3) There should be at least 12.2” of front-to-back clearance at knee height, measured from underneath the
front edge of the work surface back toward the wall supporting the work surface. Taller people will need
more clearance.
Adjusting your keyboard
If you are using a keyboard tray or platform, adjust the angle and height of your keyboard so that the front of
the keyboard is approximately at the same height as your elbows. Your forearms should be parallel to the
floor. Be careful of the following:
1) Are you striking the keys on your keyboard too hard? Try to remember to soften your touch.
2) Are your shoulders raised or hunched? Relax and lower them. If the armrests of your chair are forcing
your shoulders up, consider asking to have the armrests removed. If your work surface is forcing your
shoulders up, consider asking to have it lowered.
3) Do you keep your hands poised above the keyboard? Relax them; don’t allow yourself to keep your hands
frozen in one position. Remember mini-breaks.
4) Are you leaning against a sharply angled edge? Move back to relieve pressure on your forearms.
5) Are you leaning over to reach things in your workstation that could be placed closer? Do you often reach
behind your body or above shoulder height to retrieve something that could be moved forward or down?
Try to find an arrangement that keeps materials you frequently use within convenient reach (about 20”
away for a heavy object).
Finally, listen to your body. If you think you may be more comfortable adopting a different posture or way of
working, experiment! And if you are experiencing persistent discomfort or unusual sensations, see a health
care professional for advice.
Reprinted in part with the permission of Herman Miller, Inc., Zeeland, MI USA. Herman Miller, Inc. does not
necessarily recommend the use of the Kinesis keyboard. © 1992 HERMAN MILLER, INC., Zeeland, MI USA.
