Minneapolis VA’s custom prosthetic legs for women embrace style and function

The Minneapolis VA Medical Center is working to bring the male-dominated world of prosthetic design into a modern era, in which more women have lost legs but still want to walk around in jogging shoes, designer flats and even high heels.

“I don’t want to get married in sneakers,” said Kelly Yun, a VA prosthetic technician and designer whose left leg was amputated 6 inches below the knee after a 2018 motorcycle accident.

VA designers and engineers are studying whether women gain psychological and social benefits from modular prosthetic legs, which feature an ankle release so amputees can easily switch out 3D-printed feet that are molded to different footwear styles. Samples in the basement research lab include feet molded for sparkly red boots, red platform shoes with 3-inch heels, and black hiking sandals.

Prosthetic technology is advancing rapidly, but health insurance doesn’t pay for costly new designs unless research shows that they offer clinical benefits, said Juan Cave, a prosthetist-orthotist who is part of the research team.

“Just walk, that’s all that they care about. ... But now we’re introducing this type of product where you can put in a little cosmesis, you put a little personality into what you’re doing,” Cave said. “So you can walk, but walk with style.”

The project is far more than a vanity exercise for Minneapolis researchers at RECOVER, which is short for the Rehabilitation & Engineering Center for Optimizing Veteran Engagement & Reintegration. Other RECOVER projects include an exercise machine for people who are bedbound after surgeries for spinal cord injuries, as well as a wheelchair that can be adjusted into a standing position.

A recent federal report found a lack of appreciation for the needs of female veterans who lost limbs, a small population of 2,600 women that nonetheless grew by 28% in the five-year period ending in 2019. Saddling them with prosthetic legs that don’t match their skin tone, or with old-man shoes for footwear, can undermine confidence and reduce veterans’ chances at success after military service, said Eric Nickel, a senior research biomedical engineer who co-invented the modular prosthetic leg being used in this study.

“It’s about that self image and the body image and kind of that sense of self that you want to present to the world,” he said.

The study builds on the medical center’s expertise, as one of seven in the VA specializing in complex amputations, but also on Minneapolis’ historic leadership in production of artificial limbs. That role started in the 19th century, as workers sometimes lost arms or legs in the city’s prosperous but hazardous flour mills.

The study is recruiting 18 women with leg amputations who will then shop online for three shoe styles they want to wear. The VA is partnering with a components company in Ohio and a 3D printing firm in Spain to then create feet that fit into each shoe and attach to the prosthetic legs.

The veterans will test the various shoes by walking on a pressure-sensitive runway at the VA lab that assesses gait. Poorly fit prosthetics can cause muscle injuries and pressures sores, which amputees sometimes don’t detect because of nerve damage and limited feeling at their injury sites.

The women then will use the modular prosthetic legs and attachable footwear at home for six months. The goal is to see if it makes their lives better, easier or happier for an extended period of time.

“You know, you’re using it and you’re very excited for the first few weeks,” Nickel said. “But then after four or five or six months, are you still excited? Does it still have an impact on your life?”

The idea got its start in 2004, when RECOVER director Andrew Hansen studied how different heel heights of footwear affected human ankle movements and the development of prosthetic legs. It was accelerated by the arrival of 3D printing technology that could create precise molds of feet to match walking strides.

The study in many ways is inspired by Yun, the design technician in the lab. The 30-year-old has a native New Yorker’s sense of style and love of high-heeled shoes that make her 5-foot-1 frame look taller.

“I did not care if I was walking 10,000 miles” in New York, she recalled. “I was going to be taller by three inches at least.”

Yun turned her career ambitions from fashion design to prosthetics after her accident. She was hit side-on by an SUV, and her leg was crushed between the vehicle and her bike.

“I didn’t even have a (prosthetic) leg yet,” she said. “I just started school. I knew what I wanted to do.”

If the study is successful, the first result likely will be VA coverage of the prosthetic system. Commercial availability could take longer for non-veterans like Yun. Existing prosthetic legs cost anywhere from $10,000 to $70,000 and the goal is to keep this new system in that range.

Nickel said men also could benefit from prosthetics that make it easy to change out shoes. He recalled a firefighter who struggled to fit his prosthetic leg into a work boot when responding to emergencies and would have benefitted from the modular system.

Many veterans that Nickel has worked with favor cowboy boots, he added, but not if they are the only footwear they can affix to prosthetic limbs.