Natallie Rocha | San Diego Union-Tribune
In June, Jonah Villamil hopped on a surfboard with two legs for the first time in three years. He was testing the water with a new, 3-D-printed prosthetic leg.
Jonah calls it his “DNA leg” because of its twisty structure.
“There’s a bunch of lines on it that (the water will) just go through,” said the 12-year-old from Chula Vista. “Also, it wasn’t like weighing me down so much.”
It’s not the first time he’s tried a prosthetic leg. But it was the first time he’s played in the ocean with a leg made by Limber Prosthetics and Orthotics, a startup out of UC San Diego that’s gaining financial backing.
The company’s below-the-knee prosthetics are made using an iPhone app that scans the patient’s limbs. Then, that data is sent to a 3-D printer where Limber can produce a precise, customized prosthetic leg faster than traditional methods.
“I think one of the reasons why I fell in love with this specific project is there’s a really tangible, direct impact — that’s sometimes difficult to get with other industries,” said Joshua Pelz, co-founder and CEO of Limber. “You might work in another industry and you might impact a lot of lives. But it may not be as tangible as giving someone a device that allows them to get back on their feet and get back to their life.”
The idea for the Limber UniLeg was born in the spring of 2019 in a classroom at UCSD. The assignment was to use technology in the lab, such as digital design programs and 3-D printing, to solve a world problem.
Approximately 40 million people in developing countries live as amputees and only 5 percent have access to prosthetic care, according to the World Health Organization. Part of the issue is that traditional prosthetic limbs are crafted by hand, so the cost and time required for care is inaccessible to a lot of people.
Pelz was working toward his doctorate in engineering, when he met his Limber co-founders Luca De Vivo Nicoloso and Herb Barrack. De Vivo Nicoloso was also a doctoral student in engineering while Barrack, a certified prosthetist and orthotist with nearly two decades of experience, was helping students as a subject matter expert.
They built the first Limber UniLeg prototype alongside their professor, using a combination of materials that are stronger than everyday plastic, but allow the leg to maintain varying levels of stiffness and flexibility.
The swirled, single-body design of the Limber leg doesn’t just look cool, but it was modeled after the lightweight durability of a chollas cactus. De Vivo Nicoloso studied the plant’s structure as part of his doctoral engineering thesis and applied its ability to withstand high desert winds to the Limber UniLeg.
Unlike a conventional prosthetic limb, which is made with multiple components and tons of little metal screws, the Limber UniLeg is one piece.
Barrack, who serves as Limber’s chief medical officer, has been making regular trips to Ensenada, Mexico, for more than 20 years to help amputees who can’t afford prosthetic care. A couple of years ago, the Limber founders brought their prototype on one of these trips and managed to deliver prosthetic limbs to the community.
For Pelz and De Vivo Nicoloso, the trips to Ensenada solidified their need to turn this class project into a sustainable business that makes prosthetics more accessible.
“It was staring us in our eye when we fitted our first patients outside the classroom that we realized that ‘wow, if we really can do this at scale, we will be able to help millions of people,’” said De Vivo Nicoloso, who serves as Limber’s chief financial officer.
Limber officially launched in 2020.
Like so many innovations throughout history — from the Etch A Sketch to the Dyson vacuum — the company started in someone’s garage. The first couple of Limber 3-D printers were built in Pelz’s garage.
“It’s just been kind of grinding, pedal to the floor, going as hard as we can, working on weekends to bring this thing into reality because it needs to be improved,” Pelz said. “It’s a global crisis and we’ve been able to see it firsthand. And we’re very excited about being able to make a difference.”
The grinding has paid off.
Remarkably, Limber is garnering funding in a high-interest-rate environment where venture capital isn’t flowing into startups like it was earlier in the pandemic.
In May, Limber took home the top prize from the San Diego Angel Conference, an annual gathering of hundreds of early stage companies and investors from across the country. That first-place title also came with a $263,000 investment that has continued to grow.
Most recently, UC San Diego invested $250,000 in Limber. To date, Limber has raised approximately $1.2 million.
The money will help Limber invest in building more 3-D printers to increase its capacity and move into a bigger lab space off-campus. It will also finance clinical trials for the device, submitting an application to the FDA and its ultimate goal of launching a commercial product next year.
Limber currently has three printers and plans to build five more by the end of this year. Pelz said the goal for 2024 is to sell 200 legs in the United States. They are still figuring out a plan for international expansion.
To date, Pelz said Limber has fitted 36 patients who have a range of activity levels and spanning ages 3 to 75 years old.
The need to build up more capacity became even clearer last summer after Limber received a ton of media attention for bringing five prosthetic limbs to Ukrainian soldiers fighting in the war against Russia. While the founders continue their trips to Mexico and envision helping people in developing countries with their products, the company’s main focus right now is on building a sustainable business model in the United States.
“This is not only for people in need,” De Vivo Nicoloso said. He added that the device is not a “cheap alternative” to traditional prosthetics, but just another way to improve the quality of life for patients and how clinicians make prosthetics.
Limber is not a direct, patient-facing business. Instead, the company offers its digital design and manufacturing support to clinics that fabricate prosthetics. Limber is still developing its network of certified clinics and has yet to determine a price for the UniLeg and whether it will be covered by insurance in part or completely.
It’s not a perfect, one-size-fits-all solution for anyone with a prosthetic limb, said Jesus Mendoza, a local certified prosthetist and orthotist, who referred Jonah to Limber. Mendoza is a longtime friend of Barrack, one of the Limber founders, and he noted the benefits of the design for certain use cases.
For someone like Jonah — who needed his left leg amputated in 2020 after a sudden infection put him in the hospital — it’s given him another option to maintain his active lifestyle.
Jonah’s love of sports, like wrestling, basketball and jiu-jitsu, is what motivated him to embrace being active with a prosthetic limb. He’d been asking Mendoza for a “water leg” because he loves to surf and go on hikes with his family.
“Jonah, I just knew that he is a champion so whatever we did, he was going to make it better,” said Mendoza, whose family business ABI P&O has been helping people who need prosthetic limbs for nearly 30 years.
Mendoza works with a lot of pediatric patients like Jonah and pointed out a benefit of the Limber system. Clinicians need to make frequent adjustments to prosthetics, especially for kids who are constantly growing and changing. Mendoza said he likes that he can take precise measurements with the Limber technology and track any changes digitally, which also helps him justify those frequent changes with medical providers and insurance.
He explained that traditionally prosthetists make plaster cast impressions of patients, take manual measurements and modify everything by hand. Now, those processes are progressively digitizing across the industry. Mendoza added that the integration of digital software isn’t unique to Limber, but the startup is streamlining the workflow.
Mendoza said he is also hopeful about Limber’s potential to offer a more accessible option for patients — no matter what level of insurance coverage — who need prosthetic limbs. For instance, he said the adoption of individual 3-D printed components in prosthetics has been shown to cost less than some traditionally manufactured parts that can cost thousands of dollars.
Below-the-knee prosthetics can cost from $5,000 to $15,000, but prices really vary depending on insurance coverage and based on different device brands, Mendoza explained.
Since Limber is still in its early stages, there’s more testing to be done on the durability to see what applications it could work for, Mendoza said. In the end, it also comes down to patient preference for how different prosthetics feel when they talk with their clinician.
“I don’t think this is the right leg for everybody,” he said. “But I think it’s going to be part of the clinician and the doctors’ decision-making of who’s going to be a good candidate for this, but it’s definitely gonna add more to our toolbox and patients’ options.”
When Jonah first tried on the UniLeg at the Limber lab, he raced up four flights of stairs, skipping every other step, alongside his brothers. He had just been fitted with the new, 3-D printed prosthetic leg less than an hour before.
“It looked natural on me,” he said, adding how much lighter it felt than his traditional prosthetic leg.
For Jonah, getting fitted for a prosthetic leg from Limber helped him get back in the ocean.
His mom, Rhodalyn Villamil, was overwhelmed seeing him carrying his surfboard to the water on his own. He was born during the summer, so he’s always been a “water boy,” she said.
“It was good for me,” Jonah said. “Like just knowing that I’ll be able to use that a lot more than just walking around since it is just plastic. I won’t have to clean it that hard because also there’s just a bunch of ridges, which is very easy to clean and I’ll be able to surf and swim with it and not have to take off my leg.”