Innovative Technology Revolutionizes Prosthetic Legs

Hugh Herr was a young expert level climber when, in 1982, he became disoriented during a blizzard on Mount Washington and suffered extreme frostbite necessitating both legs to be amputated.

Aimee Mullins was born without fibula bones which required her legs to be amputated below the knee when she was one year old.

Amy Purdy, an avid snowboarder, survived bacterial meningitis at the age of 19 but consequently lost hearing in one ear, kidney function and both legs.

Adrianne Haslet-Davis a ballroom dancer and instructor, was injured in the Boston Bombing and lost part of her left leg.

Mike “Monster Mike” Schultz lost his left leg above the knee in an accident during a snowmobile race.

Gregg Stevenson lost both legs as a soldier in Afghanistan.

 

All of these individuals have augmented their experience of being able bodied. New technology has empowered them in ways that provide not only independent movement but extreme movement and flexibility. They can jump higher than the average person and run, dance and move with natural grace.
 

Prior to his accident, Hugh Herr was not a focused student but he took the accident to propel himself forward. Initially it was to develop new feet for himself to better enable climbing and then he advanced his technical work parallel with his academics. He says "Nature is driving design and design is also driving nature. Bionics explores the interplay between biology and design; my legs are bionic and bionics has defined my physicality."


These are the three bionic interfaces integrated in design:
1.Mechanical: how things are attached to the body-eg.for Hugh's legs they are attached using synthetic skins and robotic tools.
2. Dynamic: building bionic limbs to lift person in to a stride. Exoskeletons being built will relieve the physical body demands and therefore allow for extreme physical feats that will not impact metabolism.
3. Electrical-explores how it interfaces with the nervous system. Information is imbedded in the chips of the bionic limb and is then under neural command.

Today Herr is Assistant Professor at MIT and head of the Biomechatronics research group at the MIT Media Lab where he develops “wearable robotic systems that serve to augment human physical capability” and has Extreme Bionics as its center to advance the physical changes with the changes in the brain. He no longer focuses on designs for himself but for those who have difficulties that he can understand and possibly find a solution. Herr has published widely, holds many patents and has received numerous awards for his remarkable work.


Aimee has had a lifetime of wearing prosthetic legs. Since a congenital defect left her without bones in her legs, she adjusted to what was available as she grew up. And she grew up to be a fashion model, actress and athlete where she first received worldwide attention.  An honor student, Aimee was one of three US students selected to receive a full academic scholarship from the Department of Defense and was the youngest person (at age 17) to have a top-secret security clearance at the Pentagon. As an athlete, she became the first amputee in national history to compete in the NCAA and also became the first person using woven carbon-fiber prostheses that were actually prototyped after the hind legs of a cheetah. She set World and the basic design of those cheetah legs became the global standard in sports prosthetics. Then the media discovered her and she went on to become a fashion model as well as a spokesperson on beauty.

Aimee’s engaging talk on TED explains the dynamics of her prosthetic legs as well as the choice of wearing any one of 12 different legs outfitted with different shoes or artful extensions on any day.


Adrianne was with her husband who had just returned from Afghanistan, walking around and watching the Boston Marathon when the bomb went off only about 4 feet from where she was standing. She lost her foot and part of her leg. Recovery was grueling but then she heard from Dancing With The Stars which was exciting and gave her hope and focus to dance again. She performed at the 2014 TED Conference which was her first time dancing in front of an audience since she was injured. Hugh Herr had designed her bionic leg specifically for dancing after he visited her in the hospital.

Amy Purdy ignited Dancing with Stars when she danced with Derek Hough in a steamy choreographed session. Twirling and slithering around each other, Amy’s permanently pointed rubber toed feet were initially designed for swimming but magically brought grace in her dance movements. Her success is not limited to dance. As a competitive athlete, she won a bronze medal in snowboarding at the Sochi Paralympics. “If I can dance, I can walk. And if I can walk, I can snowboard. And I can live a great life,” says Purdy.


Monster Mike, a professional athlete, is a multi X Games Gold Medalist. During a snowmobile race while pushing ahead of a competitor, his snowmobile turned over and severely damaged his left leg.  As necessity is known to be the mother of invention, he created a prosthetic leg for himself. Without any engineering training, Mike used mountain bike parts to build his first prototype and then enhanced the design so it would be adaptive to extreme sports. Using it while racing in adaptive divisions of Moto X and the X Games, he won Silver and Gold medals respectively. With the formation of his company, Bioadapt, he builds and sells a variety of tough prosthetics that can withstand the demands of extreme sports.

Gregg returned from Afghanistan to his home in the UK as a double amputee. His extraordinary prosthetic limb has a Bluetooth remote control to switch from different action modalities such as walking, jogging, cycling or golfing. It’s amazing features such as being able to automatically sense and react to his movements and being waterproof (think shower or beach). Recently he received a new £70,000 Genium X model knee that is programmed from a laptop and also uses Wii-style sensors to anticipate his action and adapts appropriately as a human leg would.

To be clear, these prosthetic limbs are not mass manufactured. They are elegantly customized to the user with sophisticated instruments and calibrated with extreme accuracy. To engineer a fit,  the amputated limb extension is measured externally for its physicality and imaging of the neuromuscular interior is assessed for the best support design. And then there is the assessment of the height and size of the user as well as specific needs. In the case of  Adrianne, a dancer's movement was studied so the foot prosthetic can move fluidly with the ankle to allow for unusual movement. As a mountain climber, Dr. Herr has enjoyed the benefit of using different prosthetic feet to climb different terrain.

Bionics are making profound differences in people's lives. They are bringing ability to lives that were previously disabled and shining a bright light for a fulfilled future where there were only dim thoughts. Going forward, wearing exoskeletons will not be relegated to bionic needs but will also become universally adapted as an advantage for the able bodied. We are building a future of transparent adaptive technology for everyone.

We must accept the proposition that humans are not disabled, a person can never be broken, our built environment and our technologies are broken. We the people need not accept these limitations but can transcend disability through technological innovation.
-Dr. Hugh Herr