Alternate Dimensions

June 11, 2007
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CHICAGO — As the office furniture industry converges on the NeoCon trade show this week, a topic of keen discussion will be how to make products ergonomically suitable for a work force that today literally comes in all shapes and sizes.

"Twenty years ago we had people working in offices, but the complexion and the makeup of that population has changed," said Bud Klipa, president of Details, Steelcase Inc.'s Grand Rapids-based ergonomics brand. "There are more women, more minorities, in a work force that is aging and increasingly sedentary."

On a global perspective, Holland-based Haworth Inc. is one of several companies carefully eyeing how to adapt its products for use in Asia, where it has made substantial investments in India and China. As the difference between, say, a U.S. male and an Indian female might be nearly 200 pounds and two feet in height, it becomes difficult, if not impossible, for a product such as Haworth's Zody chair to work for both extremes.

In the domestic market, where the average American's weight has climbed nearly a pound a year since 1960, the disparity between body types is no less distinct, albeit more in width than height.

Until recently, the majority of industrial and apparel designers created product for the U.S. market based on a set of human dimensions that came from a 1988 study of U.S. Army personnel. In the study, the difference in weight between a 5th-percentile female, defined as a female lighter than 95 percent of the female population, and that of a 95th percentile male, heavier than 95 percent of males, was roughly 110 pounds. The difference in hip breadth, or seat size, between these outliers was four inches.

Recently, the results of the Civilian American and European Surface Anthropometry Resource Project were released to the general public. A partner of government, automotive, aerospace and apparel interests, the five-year, $6 million CAESAR project was the most comprehensive study of civilian human dimensions ever conducted. Following a decade of studies that showed an increase in U.S. obesity, the results came as no surprise to researchers.

"We knew people were getting larger," said Bill Dowell, director of research for Herman Miller Inc., the lone furniture company to participate in the CAESAR project. "Now we have some data that we're able to apply to that problem."

The data showed virtually no change in the height of Americans or the dimensions of the shorter, thinner outliers. The opposite outlier, however, gained 37 pounds and three inches of hip breadth. For furniture and automotive companies, which have historically designed products to meet the middle 90 percent of the population, the greater disparity between outliers is cause for concern.

"You have to look at how a manufacturer can design for the wider range," said Teresa Bellinger, senior corporate ergonomist for Haworth Inc. "Some products you can do that with; other products you might not be able to."

Seating, for instance, will soon exhaust its ability to serve both outliers if Americans keep getting bigger. Little more than a decade ago, chairs were built with a seat width of 18 to 18 1/2 inches. The seat of the Zody chair, by no means a plus-size product, is 20 inches wide. To accommodate narrower frames, the arm rests angle inward, Bellinger said, but there would be few options to accommodate the smaller individual if the seat was made wider than 21 inches.

At NeoCon, members of the Business and Institutional Furniture Manufacturers Association International will discuss the potential rewrite of its general purpose office seating standards and ergonomics guidelines to accommodate heavier loads and wider bodies. An influence to the standards, the Human Factors and Ergonomics Society this year updated its guidance with help from Bellinger and other furniture experts to include the new dimensional concerns.

"We know there is a need for a big-and-tall standard," said Richard Driscoll, director of BIFMA technical services. "We receive a growing number of calls for referrals to manufacturers with specialty lines for larger people. We know the manufacturers have responded, although they haven't shared any of their standards with the industry yet."

In February, Grand Haven ergonomics consulting firm Atlas Ergonomics LLC released a white paper detailing the effects of obesity within the workplace. In addition to the well-publicized general health risks of obesity, Atlas Ergonomics found a dramatic increase in ergonomic injury and discomfort. For the morbidly obese, the ergonomic features of a standard office chair are almost completely removed.

With only a third of office workers representing the federal definition of normal weight, the majority can expect some degree of discomfort in a standard office chair. For the most obese, the possibility and intensity of every chair complaint was increased when compared to a normal-weight individual, including lower back pain (83 percent), hip pain (200 percent), knee pain (170 percent) and foot/ankle pain (600 percent).

"Employees need to recognize the physical constraints of the chairs that they're in," said Atlas Ergonomics President James Landsman. "For those employees outside of that, we recommend big-and-tall chairs."

The standard office chair has a maximum weight allowance of 275 to 350 pounds, depending on the chair. Big-and-tall chairs accommodate around 500 pounds. Beyond that, specialty bariatric chairs are available through health care brands for persons weighing up to 700 pounds.

As part of its study, Atlas Ergonomics tracked the use of the larger chairs among participants. The workers' physical condition improved, but there was a negative emotional impact, particularly among female employees.

The 21-inch-wide maximum for seats applies for many automobiles as well, although unlike furniture makers, there are no larger seat options available for the outliers, only larger vehicles.

"The average width was narrower before. Now accommodating the width of a seat is becoming a bigger problem," said Ben Delphia, former Chrysler and Magna Seating Systems designer, and lead instructor in the automotive interior design program at Kendall College of Art and Design of Ferris State University.

"If you have a vehicle designed with a certain width side-to-side between the two front doors, you're going to have some trouble getting a wider seat in and still having room for a counsel with cup holders and things. In a sporty car, a real wide seat is going to be 21 inches, and we're finding that sometimes isn't enough."

Other dimensional concerns aren't much of an issue, Delphia said, as adjustable seats easily fit drivers into long-standardized height requirements — known as the "eye ellipse," the legally required position of the eyeball in relation to the driver's line of sight. It is occasionally a concern for global models, Delphia said, such as the failure of early Japanese imports to accommodate taller Americans.

Federal regulations dictate load-bearing requirements and other standards such as the "belly clearance" necessary for heavy-duty trucks. Ergonomic opportunities still exist, according Atlas Ergonomics' Landsman, but mostly for individuals who drive for several hours at a time.

Chuck Saylor, president and founder of izzydesign in SpringLake, is less worried about meeting the needs of larger bodies than the opposite outlier.

"The biggest impact of this is that maybe more products will be designed for women," he said. "As an industry, we haven't done a good job of designing for women. They are built quite differently than we are and they sit differently. These are unique attributes that most guys designing products don't take into account."

Saylor is proud that izzydesign's products have been built with a narrower profile than the industry standard, and he said that he intends to soon hire a woman designer for the specific purpose of designing an office chair for women.

"Workers aren't just getting larger, they're getting smaller," he said. "With the globalization of our economy, more and more women in the workplace, more Asian influence — workers are going to start finding products scaled too big for them."

Rather than design products to meet both ends of the spectrum, Saylor believes that manufacturers will instead turn to mass customization.

Since its inception, Herman Miller's bestselling Aeron chair has been available in three sizes: one for the majority of users, and one each for the two outlying body types. As a CAESAR sponsor, the Zeeland furniture maker received the data three years ahead of its competitors and applied the knowledge to the launch of its Mirra office chair in 2003.

The outliers for the Mirra chair, however, were not adjusted dramatically, nor were additional models launched to accommodate them. Instead, dimensional variances were designed into the shape of the chair back. Where the data revealed a larger degree of variance, the chair was more flexible; where there was less variance, it was stiffer.

"The linear dimensions, like width, are pretty easy," said Dowling, the Herman Miller research director. "But what about the girth of the leg? Or the curve of the back? Those are multiple dimensions."

The CAESAR project three-dimensionally recorded millions of different head-to-toe variables. Some of that information, such as the circumference of the head, is completely useless to furniture makers.

"Right now we don't have the tools to use the data," Dowling said. "We need a way to harvest the data, maybe a whole new language to describe it. Once we figure out how to do that, the possibilities could be infinite."

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