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Groundbreaking prosthetic foot designed by University of Washington inter-disciplinary team is launched by WillowWood

Written by Debra Bouchegnies / May 24, 2021

META Arc’s unique design and performance addresses top movement challenges among prosthesis users, especially uneven terrain

Stepping over a raised curb, navigating a dark room at night, or taking a walk at the beach are activities most people do without giving them a second thought. Yet each poses unique challenges for people using prosthetics. Nearly 2 million people in the United States live with limb loss – a number expected to double by the year 2050 – and the Amputee Coalition of America estimates that there are 185,000 new lower extremity amputations each year.  

Some of the most challenging issues people with lower limb loss face while using currently available prosthetics include traversing uneven ground, slopes, and rough surfaces limiting their ability to participate in everyday activities. The recently launched META™ Arc prosthetic foot is uniquely equipped to address these concerns. Designed by a team at the University of Washington led by physical therapist and UW School of Medicine associate Professor, Murray Maitland PT, PhD, in partnership with prosthetics design and manufacturing group WillowWood, LLC, the META Arc is revolutionizing the world of prosthetic feet.  

What sets the META Arc apart from other prosthetics?

The biggest difference between the META Arc and other foot prosthetics is its polycentric arc ankle and unibody design. It is inspired by previous mechanical models of human joints and developed in Maitland’s research. The foot is designed with a single point of contact at the joint, allowing the ankle to operate around a moving instantaneous center of rotation, replicating behavior of the human ankle. This allows for immediate adaptation across the widest range of ankle motion and reduces pressure on the residual limb for natural-feeling stability. It is this innovation, combined with WillowWood’s groundbreaking unibody carbon fiber design which eliminates traditional bolts or an adhesive foot connection. This results in an end product which is stronger and lighter-weight than many other prosthetics.

The team behind META Arc

Dr. Maitland received a B.S.R. in Physical and Occupational Therapies at the University of British Columbia. He earned a PhD in Medical Science in 1996 from the University of Calgary eventually joining UW Medicine’s Department of Rehabilitation Medicine in 2006. By 2014, Maitland was working with an interdisciplinary team of experts, including Kate Allyn, a state and board-certified Prosthetist/Orthotist and UW consultant, along with Dr. Kat Steele, UW Professor of Mechanical Engineering and Adjunct Associate Professor in the Department of Human Centered Design & Engineering.

Bumps in the road on the path to commercialization

In the beginning, Maitland remembers struggling to get commercialization partners onboard with the vision he saw for his polycentric ankle design. A Coulter Foundation grant early on helped establish the project, but the team also needed manufacturing support for prototypes. Maitland recalls cold-calling many potential partners with Kate Allyn before finally finding WillowWood. It turned out to be a great fit. Along with their 100+ years of experience in prosthetics design and manufacturing, WillowWood has always been supportive of research, providing innovative solutions for prothesis users. It would be a couple more years before Maitland was able to secure the partnership, but early prototypes of the prosthetic demonstrated to WillowWood that amputees could walk more effectively with the ankle structure Murray designed, which helped them see its potential impact. 

While the need for prosthetics innovation continues to grow, the field of licensed prosthetists who can support the design is limited, with only about 4,000 certified practicing individuals in the U.S. This makes it challenging to effectively communicate needs from patients and designers to manufacturers in the innovation process. “A multidisciplinary team of experts from academia and industry can overcome challenges and facilitate the transition of an innovative idea from theory to commercialization,” said Kate Allyn, LCPO, FAAOP.  “The University of Washington and WillowWood have parallel goals: to transform ideas into shared impact.” 

The UW & CoMotion Boost

“Getting products onto the people that need prosthetic technology should be the end goal, and that is where CoMotion comes in.” – Kate Allyn, LCPO, FAAOP

Throughout the process, the team found support via several programs including the CoMotion Innovation Gap FundInstitute of Translational Health Sciences (ITHS) and Washington Research Foundation (WRF) Commercialization Fellowship ProgramCoMotion Mary Gates Innovation Scholars, advisors and managers. CoMotion was also able to set Dr. Maitland up with patent lawyers to help with licensing and nondisclosure agreements. The personalized advice and support of Ryan Buckmaster, his CoMotion innovation manager, and the engineering consultants, have been long-lasting. “The University of Washington technology transfer support through CoMotion has helped me the entire way. Even now as we’re going through to the next level, I’m still asking advice.”

What's next?

META Arc launched at the end of April, and the response is already showing positive impact. “The feedback from users [has] been so positive, beyond what I thought [it] would be,” said Jim Colvin, Director of Research and Development at WillowWood. “[The Meta Arc] technology can have a very strong positive effect on people’s ability to go out and do some of the things they want to do.” 

While the META Arc foot is designed for moderate to higher activity users, the technology has also opened the door to future research and development for lower activity users, including the potential to reduce or even eliminate falls for prosthetics users in all activity groups. Maitland also envisions possibilities of bringing the technology to the youngest groups of amputee users, allowing children to have the freedom to run, jump and play on the playground with friends. The release of the META Arc prosthetic is an incredible advancement in lower limb prosthetics and opens the door to a large variety of prosthetic possibilities for the future.