Choosing an Office Chair: An Informed Decision for Comfort and Health

The complex challenge of choosing an office chair involves the critical issues of optimal employee health and performance, as well as environmental sustainability.
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The Complex Role of Today's
Task Chair
  • Supports the dynamic positions of sitting, including reclined postures
  • Supports the lower back
  • Is adjustable and able to fit different body sizes
  • Provides both cushioning and support where it contacts the body
  • Designed to support environmental sustainability
  • Has aesthetic appeal
  • Requires minimal training

Seating as a Dynamic Activity

Because sitting should be a dynamic activity, the office task chair also needs to be dynamic to support the user's many macro and micro movements throughout the day. According to the U.S. Department of Labor Occupational Safety & Health Administration (OSHA, www.osha.gov), "A chair that is well-designed and appropriately adjusted is an essential element of a safe and productive computer workstation. A good chair provides necessary support to the back, legs, buttocks, and arms, while reducing exposures to awkward postures, contact stress, and forceful exertions. [Dynamic] adjustability ensures a better fit for the user, provides adequate support in a variety of sitting postures, and allows variability of sitting positions throughout the workday."

But supporting the user is not sufficient. The chair must support the user in the context of working, while he or she is doing different tasks such as reading documents, viewing the monitor, writing by hand or keying. Leaning back in the chair may provide optimal comfort, but it may not be possible to do if the other components such as the keyboard, mouse and monitor are not ergonomically integrated into the workstation. The office chair must be viewed as part of the workstation environment in a holistic context.

Galen Cranz, author of The Chair: Rethinking culture, body, and design, published in 1998, earned applause for her review of the chair in history, but provoked considerable criticism over her views of the chair as an ergonomic object. "Insofar as the chair stabilizes posture, it contributes actively and directly to disorders of the eye, back and wrist," she writes. "People cannot take advantage of ergonomic chairs, with some capacity for movement built in, because their eyes and hands become entrained with the keyboard and screen they are working on. In this case we cannot really blame the chair-it is simply part of an integrated complex of chair-keyboard-person-screen, which together forms a new machine."

Cranz's conclusions regarding the computer workstation as a 21st century version of Taylor's scientific management are certainly arguable. But her point that the rest of the workstation impacts seated posture as much as the chair itself is telling. Employees may have the best chairs in the world, but if they have to lean forward to use the keyboard or see the monitor, they simply won't be taking advantage of their chairs.

Recognizing the critical need for a holistic approach to the workplace, the Cornell Human Factors and Ergonomics Research Group (www.ergo.human.cornell.edu) has developed a Performance Oriented Ergonomic Checklist For Computer (VDT) Workstations. According to Hedge, the most important things for creating a healthy workplace posture are a good ergonomic chair, optimal keyboard and mouse position, and optimal monitor and document position. "Other furniture items, such as overhead storage, pedestal storage, work surface area and work surface finish, which constitute the bulk of the costs per workstation, are almost irrelevant from an ergonomic standpoint," he says. "Consequently, companies can readily cut furniture costs by minimizing the less essential items and reallocating funds to improving the immediate workspace of the seated worker, which is the micro-environment that actually affects their health and performance."

Seating Adjustments for All Sizes

Since people come in all shapes and sizes, one major challenge is identifying a chair that will fit most people comfortably. Manufacturers generally design chairs to fit the 5th percentile of women to the 95th percentile of men, which theoretically covers 90 percent of the population. This range is overly optimistic for several reasons according to one manufacturer. First, most of the data collected for anthropometric studies come from military populations, which include fewer very large and very small people-and no people with disabilities-compared with the general population. That data also focuses on skeletal dimensions, says Hedge, to the exclusion of soft tissue contours. Second, dimensions may fall below the minimum or above the maximum percentile for different people for each chair component (seat height, seat depth, lumbar support, armrest height, etc.). This means that more than five percent of women and five percent of men may find at least one chair component that doesn't quite fit.

The Experience of Specifying
Task Chairs

Whether the client is a Fortune 500 corporation or an architectural firm, selecting the "right" chair is critical. Equally critical is the process undertaken by designers and facility managers to not only select that right chair, but to pre-select a number of right chairs so that clients are presented with a choice.

Brian Berry, AIA, senior associate and design director of Gensler's Wall Street office in New York City, works with clients in the media, fashion and financial sectors. "For those clients who have pre-existing chair standards, we begin the process by evaluating what they currently have and making recommendations, possibly to improve or modernize their standards. Most clients today are interested in ergonomics, durability and obviously, cost, which is always a huge factor-especially for larger projects.

"We develop a series of five or six chair images which we will bring in and talk to the client about why we feel they are appropriate. Sometimes they want to see all of them, but typically we narrow the field down. I prefer to have the vendor's representative come to the first meeting to demonstrate the different features because every chair is different. At Gensler we have a great knowledge of chairs and the manufacturers who are reliable and have provided chairs over time that are durable. We have a full time library staff that keeps track of all the new chairs and what's good and bad out there. If a chair has had a problem on one of our projects around the country, we will know."

"Our bias is to specify chairs that offer key manual adjustments combined with automatic adjustability features," says Joe Connell, principal, The Environments Group, Chicago, IL, whose interior design firm does mostly corporate workplace projects. "There are a lot of task chairs out there and most of them offer, initially, good comfort, but how does your body feel at the end of the day? That's the real question.

"The more expensive chairs last longer and are field-repairable. We don't like the idea of a client throwing away a chair when it breaks and buying a new one. We look at life after the chair is no longer in use.

Can it be easily broken down and recycled? We want no vinyl, the fewer plastics the better. Polished aluminum is better than chrome on steel because it is easily recycled." If someone has an injury, Connell may suggest an ergonomic consultant so that the person may make his or own choices. This results in few complaints later, he adds.

Many clients ask employees to vote on their chair preferences. Ideally, workers should try out different chairs at their workstations, sitting on each for at least a week. "Usually the client will keep the samples for a week or so and test-drive them," says Berry. "I'd love for people to test the chairs, get up and down, move around, be on the phone, be on the computer, do the different things a person might do. That's the best thing for people who are in the office all day."

 

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Originally published in Architectural Record
Originally published in December 2007

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