Stanford Arthritis Shoe Hits Shelves

By Kathy Seligman

Tom Andriacchi

Tom Andriacchi

Tom Andriacchi has spent the past 20 years investigating the mechanics of how we walk.  In his BioMotion Lab, Andriacchi and his team use cameras and sophisticated software to analyze the walking gaits of patients with diseases of the knee. The most prevalent of these is osteoarthritis, a disease affecting more than 20 million Americans, caused by deterioration of cartilage. Andriacchi’s research has led not only to a greater understanding of osteoarthritis but also to something he never expected – a line of shoes that helps people suffering from the painful condition.

“How people walk has never been considered a clinical factor in surgical outcome, but it should be,” said Andriacchi, a professor of mechanical engineering and orthopedic surgery. “We came to the conclusion that if you could control the force of the walking pattern and change it, maybe you wouldn’t have to go through surgery.”

The story of how his laboratory research became a practical solution for an aging population is a story of collaboration, entrepreneurship and perhaps a bit of serendipity.  Andriacchi’s work has been shepherded by the Stanford Center on Longevity, where he is a member of the Faculty Steering Committee. In the spring of 2011, The Walking Company began selling the ABEO SMARTsystem™ line of shoes based on Andriacchi’s research. The shoe project marks a milestone for the Center on Longevity.

This is the poster child for us,” said founding director Laura Carstensen. “There are an awful lot of important ideas that academics generate and then sit back and hope someone adopts. Most researchers are not trained to move ideas past the conceptual stage. What we do at the center is to show how and where those ideas can be useful. We help to move practical ideas, based on science, forward to a place where they can positively affect peoples’ lives.”

At the outset of the project, Andriacchi didn’t consider himself either an authority on aging or “a shoe guy.” He was, however, a world-class expert on gait and osteoarthritis.  Carstensen said it took “about 60 seconds” to convince him to work with the center. The collaboration fit perfectly into the center’s mission of redesigning long life by using Stanford research to help people arrive at old age physically fit, mentally sharp,  and financially secure.

In the BioMotion Laboratory, Andriacchi’s team stationed cameras strategically to record the gait characteristics of volunteer subjects. Both people who were healthy and those with osteoarthritis of the knee were included in the study. Forty-two markers were placed on each subject that allowed the team to measure alignment of the pelvis, knee and ankle.  Sensors in the floor measured the force of the subjects’ footfalls in three dimensions.  The data were recorded by computers and used to create a structural model of each knee and the resulting forces on each individual’s cartilage.

Using this body of data, Andriacchi was able to show that adding a wedge to shoes forces the foot slightly inward and the knee away from inflamed cartilage, reducing pain. Unfortunately, the wedge had to be fairly large, which made walking uncomfortable.Andriacchi turned next to an “active feedback device,” a sensor placed under the foot that vibrated when people walked in ways that put high loads on the cartilage. The subjects were trained to alter their gait when they felt the vibration. That was effective, but not practical. “We couldn’t guarantee that the training would hold or that that people would wear the sensor all the time,” he said.

But the work on the sensor yielded important results. It demonstrated that a relatively small shift in foot angle could have a profound effect on pain. This finding led Andriacchi to reason that creating a sole with a varying stiffness across the width of the foot could accomplish much the same result as the wedge.  The result was a shoe that was both comfortable and effective.

The Center on Longevity was considering how to apply Andriacchi’s research in 2007 when Mike Walker, vice president of The Walking Company, read about the work in a Stanford publication. He contacted Steve Goldband, a research scientist at the Center on Longevity and serial entrepreneur.  Goldband saw an opportunity for the Center to provide the help necessary to get the shoe into production. “The shoe didn’t fit into the existing footwear market,” said Goldband.  “Professors are usually busy pursuing their research and innovation. When that coincides with marketing that’s great, but that doesn’t usually happen. There is often a gap.”

Goldband helped Andriacchi and The Walking Company bridge that gap, working through issues ranging from design to intellectual property. In the end, Andriacchi’s concept appealed to The Walking Company, which was looking for new technology. Together they created the ABEO SMARTsystem collection.

“The reason why we were interested in creating this innovative collection is because it appeals to people who are aging, i.e. most of us,” said CEO Andy Feshbach. “If you’re 50 you have the expectation to live to 85 or 90, but your bones, cartilage and ligaments haven’t caught up with our evolving lifespan. The need for comfort is growing dramatically based on longevity.”

And these days older customers know what they want; shoes that are functional and attractive, says Feshbach. People who remember being teased about orthopedic shoes in grammar school are now bragging about where they’ve bought their latest sensible pair.  The Walking Company’s goal with ABEO SMARTsystem is to combine technology and biomechanical intelligence with appealing design.

The ABEO SMARTsystem features six styles each for men and women,. The SMARTsystem collection retails for $140 per pair, and can be found exclusively at the Walking Company’s 210 nationwide stores and Andriacchi, who often wears a pair, tests new styles in the lab before they are approved for sale.

His focus now is to determine whether the technology can be used not only to reduce knee pain, but also to slow the progress of osteoarthritis. If so, the shoe could prove to be the first noninvasive treatment for the disease.It would be none too soon for Baby Boomers, the first of which turned 65 this year.

“If we want to make changes to the culture in the near term we have to develop a way to efficiently bring discoveries to the public,” said Carstensen. “With 10,000 boomers turning 65 each day, we don’t have time for the traditional ways that research findings make their way to themarket.  We need to think differently and we need to do it quickly.”