How a state-of-the-art prosthetic leg helped this amputee win a silver medal at the Invictus Games

Retired master corporaltienne Aub's golf swing won him a silver medal at the Invictus Games, an accomplishment the Canadian veteran credits to his state-of-the-art prosthetic leg.

The prosthesis reflects 20 years of technological progress. The microprocessor powering it instantly analyzes and responds as the user shifts their weight.

During Aub's second deployment in 2009 near Kandahar City in Afghanistan, he hit an improvised explosive device.

Aub was 28 at the time with a wife and a young son and daughter. Doctors told him only five per cent of people with his type of trauma to the leg are able to walk.

"I was conscious [during] all the travel to the hospital in Kandahar, and I was talking to myself in the helicopter. And I said, 'We'll see now if you're a real man, because your real combat begins now.'"

Aubsaid that "everyone took the bomb with me."Over the course of three surgical amputations, his family grew closer.

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Surgeons removed the kneecap and tibia of his right leg. The prosthesis fits into a silicone sleeve on the leg.

Changing his mindset about his recovery, he became passionate about progressing on the golf course. The quiet greens complemented his rehabilitation with both physical and psychological boosts.

The military paid for Aub's eight-kilogram prosthetic device. The Ottobock X3 is a sophisticated, $100,000 model with a micro-processor aboard. Gyroscopes help situate it and calculate the speed of weight transfer between Aub's legs, allowing for fluid movements.

"It's updated instantly, something like 300-400 times a second," saidShane Glasford, acertified prosthetist at the Sunnybrook Centre for Independent Living in Toronto.

Glasfordleads the custom-made prosthetics lab. Physicians, prosthetists, prosthetic technicians, occupational therapists and physiotherapists work together with patients who've lost limbs.

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The majority of cases are geriatric, Glasfordsaid. Diabetes and peripheral vascular diseaseare the main reasons for amputation. Trauma from motorcycle accidents anddiseases such as cancer, including Terry Fox's malignancy, also come into play. A small subset are children who were born without limbs.

Energy intensive steps

Beyond rehabilitation, there are other daily challenges for people wearing a prosthesis. Glasford said they commonly perspire a lot, because loss of skin or scarring also reduces the temperature-regulating properties of the skin.

For some, cosmetic concerns are top of mind. Others are pleased with as futuristic a look as possible.

"For an above-the-knee amputee, you're looking at 60 to70 per centmore energy just to do the basic, everyday things,"Glasfordsaid.

While our knees are wired internally with nerves and muscles that allow movements without conscious thought, Glasford said a new amputee has to think about taking a stepand keeping their weight in the correct place.

For bilateral amputees, standing can be difficult, just as trying to stay still on a bicycle on two wheels isn't as easy as moving forward.

When someone wearsa standard prosthesis, walking on uneven pebbles will cause the knee to buckle, which can lead to a fall.

"The microprocessor knees will recognize that's happening," Glasford said. "It will lock those valves up and catch the amputee on the way down, just hopefully enough to get their second foot down to break the fall."

Glasford said military prostheses, for instance, are designed for a soldier in the field who needs to carry an injured buddy. The demanding conditions mean the microprocessors in the prostheses are built to withstand mud and moisture.

He looks forward to the next generation of devices with "forced feedback." It gives users a sense of grip and whether they're touching something smooth or rough, hot or cold.

For upper-extremity amputees, Glasfordsaid, replicating the range of functions of a hand is almost impossible. The hospitalgenerally offers a variety of devices, such as a clamp, vise grip or hammer.

Glasford called it rewarding to work with those at the top of their game, such as athletes and accomplished musicians. They may come back countless times for minute adjustments that others wouldn't notice.

Often the biggest challenge, Glasford said, is trusting the device and its microprocessor to put weight on it.

Aubsaid he doesn't feel anything as the scope adjusts. "That's why sometimes downhill or in stairs, I have to watch my feet."