Tom Andriacchi’s pristine white shoe looks like any other Nike. But its small difference could make a big difference in the world.
Try it on, and it feels like a comfortable walking shoe. If you start to walk quickly, however, you might feel a subtle alteration. The cushioning in the midsole is stiffer on one side of the shoe than the other. The effect is to shift weight so there is less pressure on the cartilage of the knee.
Andriacchi, professor of mechanical engineering and of orthopaedic surgery, designed the shoe to help ward off osteoarthritis, which results from the deterioration of joint cartilage. Especially as people age, the cartilage begins to wear down, causing pain and ultimately making it difficult to walk normally, or to walk at all. Andriacchi’s shoe is designed to reduce the “peak load” on the knee.
Here’s why it will make a difference: 40 million Americans have osteoarthritis, Andriacchi says, and by 2020, that number likely will rise to 59 million. “Osteoarthritis is probably the major cause of functional loss in people over 50. It’s huge.”
Andriacchi thinks mobility is the No. 1 factor in a successful old age. But it’s not just a matter of being able to get around and maintain independence—though that alone is a major issue for the elderly. “The key is, if you can move, you can exercise your cardiovascular system, your neuromuscular system,” he says. “The body needs mechanical demands on it for maintenance. Even cartilage tends to wear away with disuse. And if it’s painful to move your knee, you won’t move it. You have to keep active, keep moving—and one way to do that is take away the pain.”
Another reason the shoe is important is that it is the first practical product of the new Stanford Center on Longevity. The shoe project underscores that the center will be more than a think tank, churning out papers and talking points for op-ed writers to mull.
Modern science has given a great gift to humankind: “Time. And lots of it,” says the center’s director, psychology professor Laura Carstensen. At the turn of the 20th century, Americans’ life expectancy at birth was 47. A century later, 30 years had been added. However, she points out, nothing changed significantly in the way we visualize the human life cycle. In effect, the extra time has been tacked on at the end of life, when it seems least needed.
“What if,” Carstensen asks in a forthcoming book, “we began to ask the serious question: Where should the extra years go? We could insert them anywhere. Life stages are social constructions, not absolute realities.”
For example, she explains, we have structured life so that people at the high point of their careers are juggling home, work, children and sometimes caring for elderly parents as well. Why not restructure life to allow more time for child rearing? Why not extend careers into later life?
These sorts of questions are likely to be more fruitful than “focusing on small questions—like whether retirement should be pushed from 67 to 69 or what sort of prescription drug privileges should be covered under Medicare,” Carstensen says. “When we accept the current state of affairs and plan policies around it, we ask, ‘How are old people failing?’ instead of ‘How is the culture failing to support and profit from long life?’”
That’s why Carstensen and her colleagues have what she calls “the modest aim to change the nature of human aging.” To that end, faculty from all seven Stanford schools will participate in the center’s work. “Our strength is research across disciplines—from economics to psychology to engineering,” says Tom Rando, associate professor of neurology and neurological sciences and the center’s deputy director.
One area researchers will focus on is mobility—reversing or arresting the effects of physical deterioration, and finding ways to accommodate limitations through, say, revamped walking shoes or mass transportation. Another study will examine how aging populations will affect the poorest parts of the globe, where AIDS and warfare already are stripping away working-age populations. Carstensen and her colleagues also will concentrate on how best to use the years of life gained in the last century. “However,” Rando stresses, “our focus and goal is translation and integration outside the University.”
For that reason, overtures are being made to outside groups. “We’re at the stage of discussing the kinds of projects we might do together,” says senior research scientist Steve Goldband, who directs the center’s private-sector initiatives. For example, a car manufacturer is considering the needs of elderly drivers. A semiconductor company is developing sensor networks so that older people can be monitored while maintaining independence. An investment firm is studying the financial needs of an aging population.
“Corporations, government, nonprofits, journalists, writers, documentary filmmakers—we’ll include them in these discussions early on,” Carstensen says. The general public can participate through town hall-style meetings as part of the McNeil/Lehrer Productions series By the People, which employs a technique devised by James Fishkin, professor of communication. His “deliberative polling” promotes informed decision making by recruiting a representative sample of citizens and giving them in-depth information on different sides of an issue to fuel discussion.
Each research area is a “plan of action we will take on and pursue for two to three years,” says Carstensen. And at the end of each there will be “real products”—such as Andriacchi’s shoe.
Although it seems a simple innovation, the shoe is the culmination of decades of research. Andriacchi has been studying ways to relieve arthritis on the knee since his career began as a postdoc in 1974. At that time he started to test “gait characteristics” of patients who had osteoarthritis of the knee joint, trying to figure out how they might move differently to protect the deteriorating cartilage. Then he proceeded to study existing solutions: a knee brace in the early ’90s—then a lateral wedge to put into the shoe.
“The research was not linear,” Andriacchi explains. “We went through a number of iterations of this shoe. A lot of them weren’t comfortable. You can’t look at these shoes now and know they are something other than a regular shoe. But the early versions definitely looked like an orthopaedic shoe.”
Nike made the shoes, and they donated to Andriacchi’s lab to help develop the prototype, the upper portion of which resembles Nike’s Pegasus model. “We were sure that we would partner with them to have this as a product,” Andriacchi recalls.
While the research group cheered them on, however, the Nike marketing people vetoed the idea. Their reaction illustrated the stigma, or at least marginalization, associated with products for older, particularly disabled, people.
“I think the basic conclusion was that this wasn’t for performance, it’s for treating a disease,” Andriacchi says. “But we knew we had a great finding. My goal is to get this to as many people as possible.”
So Andriacchi posted the unusual business opportunity in the Graduate School of Business’s Center for Entrepreneurial Studies. He got a response from four athletic Business School students—Kermit Jay Cook, Ryan Robinson, Vini Letteri and Eric Edelson—who just happened to be looking for a way into the shoe industry. “They couldn’t arrange a meeting quick enough,” Andriacchi recalls.
“We were all excited about it. We had a lot of fun working on it,” Cook says. “We’ve been talking to a lot of people—potential consumers, doctors, shoe stores—figuring out who we would sell it to, what people would be looking for, how much they’d be willing to pay. We’re also talking with people who manufacture shoes.”
Andriacchi notes that walking and running shoes generally last about six months—that means two pairs of shoes every year. “If they touch 5 percent of the population, that’s a darn good market.”
Out of the 40 million with the disease, adds Cook, “11 million have enough pain to limit their everyday possibilities. If the shoe helps to reduce pain, there’s a real consumer need.”
There’s more work ahead: Andriacchi’s team is finishing clinical trials at the Palo Alto Veterans Administration Hospital, and so far the results are “really promising.” He will present his results at the American Society of Biomechanics at Stanford in August. Meanwhile, the business team is poised to look for venture capital.
As Andriacchi says, it’s a step in the right direction.
CYNTHIA HAVEN is a frequent Stanford contributor.
