A better foot forward

A better foot forward

The great strides in prosthetics development since the Marathon of Hope.
September 12, 2013

As thousands of people lace up their running shoes this Sunday for the annual Terry Fox Run, many will remember the perseverance of the young hero whose Marathon of Hope in 1980 helped raise awareness of cancer, the disease that robbed him of his right leg, and ultimately, his life.

Like many of these runners, Tim Bryant, a mechanical and materials engineer at Queen’s University, has a vivid memory of the footage of Fox running in the rain with a trail of support vehicles following him, their lights flashing. “I remember thinking how hard he had to work to make those legs work,” says Bryant. “Terry didn’t have the best prosthesis in the world. But in the eyes of people who designed these things, we knew Terry was doing the thing he wanted to do and that limb helped him do it, no matter its limits.”

Bryant has spent most of his career designing, building and improving prostheses, such as artificial hips and knees. Recently, he began working with an international consortium to produce external limbs for developing and post-conflict countries. One example, the Niagara Foot, is an artificial foot that can be assembled using modern low-cost plastics that can be easily sourced in many of these areas.

With funding from the Canada Foundation for Innovation, Bryant and his colleagues at the Human Mobility Research Centre at Queen’s and Kingston General Hospital have built a motion analysis lab with materials testing equipment, computer vision systems and rapid prototypers which allow them to quickly solve problems. Bryant likens his work to the TV drama, CSI. “You know when they’re trying to investigate a crime and they run a simulation in the lab and get an answer in a matter of minutes?” says Bryant. “Our lab works along the same lines. We can ask how a prosthesis will work under certain conditions and get an answer very quickly.” This allows Bryant to deliver solutions to prosthetic companies in a matter of days.

But the speed of testing is not the only improvement in the world of prosthetics over the last three decades. Bryant says modern artificial limbs couldn’t be further from the stiff materials and uncomfortable fit of Terry Fox’s prosthetic leg. He lists a few examples ranging from lightweight carbon fibre materials that store and release kinetic energy to battery-powered limbs that use the body’s motion as a source of renewable energy — like using your hip as a charging dock. Bryant imagines artificial arms and legs of the near future will be linked to a person’s smartphone, beaming data to a prosthetist who can make any necessary adjustments on the fly — like a remote-controlled limb tune-up. 

Bryant also suggests the bits and pieces needed to build a hand or hip in the future will be much smaller and sturdier. These miniature components may be combined with new materials to allow for rapid prototyping and precise custom design on a massive scale. From there, he says it won’t be long before we see prosthetic limbs built by 3-D printers. In go the materials and design. Out comes an artificial foot.

Casting even further into the future, Bryant sees a day when artificial limbs will boost natural abilities — a bionic leg that helps you jump higher, an augmented arm for a more powerful golf swing and a mechanical eye that enhances your view of the world. “The line between human and machine will be blurred,” he says. “These machines will range from arms or legs, right down to the micro level and into your cells.”

Bryant is confident such cyborg-like fantasies will become reality in a matter of decades, given the technological strides made in the years since the Marathon of Hope. The speed of change and innovation has improved the world of prosthetics, bringing with it agility and dignity to those who have lost a limb. Now, they can walk, jog or run in ways never imagined more than 30 years ago when Terry Fox faced down the odds and did his best to run across Canada.

Photo courtesy of The Terry Fox Foundation