Move 20 or 30 new chairs into an office and watch the users adjust them 20 or 30 ways. It is evidence that even advanced ergonomic research, which seeks to adapt the work environment to the needs of the worker, has not produced the one-size-fits-all and one-price-suits-all seat behind a desk.
"Everybody's idea of comfort is different," says Keith McDowell, an engineer who develops bus seats for American Seating Co. in Grand Rapids, Mich.
Robert Johnston, spokesman for Herman Miller Inc., a major maker of office furniture, says, "We've found that comfort is both physical and psychological." Chair design is "more dependent on how a person likes to sit and the type of activity performed."
Mary Nelson, administrative assistant for business operations in the Hartford district office of Xerox Corp., has used a series of ergonomic chairs.
"The one I'm in now is the most comfortable," she says, adding that she has used it for three months. "I don't feel like I have to keep adjusting it. I like it."
In his office at Aetna Life and Casualty Co. in Hartford, Thomas Greaney, administrator for corporate affairs, has been sitting in an ergonomic chair for about a year and says he appreciates its back support as an improvement over his previous chair.
Karen Odlum is Aetna's manager of facilities issues technology and development, which initiated a corporate quest for the right chairs. The products of four chair manufacturers were rotated among 100 employees to use and report on, she says.
The final choices were ergonomic, self-adjusting chairs made by Steelcase Inc. in Grand Rapids, Mich. They easily adjust for changes in the height of work surfaces, as when working part time at a computer keyboard.
Stanley Frank, author of a 37-page booklet "How to Prevent Office Backache .
. and Sitting Fatigue," writes that, although many chairs are presented as "ergonomically designed," the more adaptable chairs are quite complex and viewed by many businesses as too costly.
Johnston, manager of corporate relations at Herman Miller, which is based in Zeeland, Mich., disagrees. He says his company's four lines of office chairs all work on the same ergonomic principles, even though they range in price from $270 to more than $1,000.
As the computer has become a common tool in many office settings, all four of the Herman Miller lines are intended to accommodate keyboard users. To design the proper chair, engineers have studied the kinds of tasks that office workers, from clerks to senior managers, must perform. Most have hand controls for adjusting seat height, back height and tilt tension; others also have adjustments for seat depth and back angle.
For example, Herman Miller's Ergon 2 "seat pan is designed as a catcher's mitt" for baseball _ "a nice comfortable place to sit into," Johnston says.
Another model is styled "for active sitting _ mostly used by professionals and upper managers _ in a job that might require computer use, time on the phone, reading time or discussion time with others," he says.
If you are shopping for an ergonomic chair for your work place or home office, Stanley Frank's booklet offers these suggestions:
Seat height adjustment should be pneumatic for instant readjustments for different tasks.
The ideal seat should be about two-thirds the length of your thighs and buttocks when seated.
The seat and back rest should be contoured to the body and padded enough for comfort. Look for a resilient seat cushion.
Do not choose a chair that is too soft. The seat should be firm but not too hard.
The front seat edge should be rounded and should not have a lip or welting.
The back rest must be full-sized, from 14 to 21 inches high, to support upper and lower back.
The back rest should include a built-in lumbar support and be height adjustable to fit the lumbar curve, or lower part, of your back.
The chair back rest should be equipped with easily adjustable settings that lock into any fixed backrest angle.
Upholstery should be of a fabric that breathes, or leather, to dissipate heat and moisture.
Arm rests are important for long-term sitting work. They should be no more than 8 or 9 inches high.
Frequently used adjustment controls should be simple to operate and easy to reach.
Casters should provide adequate ease of mobility but not allow the chair to roll too freely.
For a free copy of the booklet, write to "End Backache" Frank Eastern Co., 599 Broadway, New York, N.Y. 10012, and enclose $1 for postage and handling.