Going the distance: Amputee develops innovative sports crutch

Few people can say they’ve climbed two of the tallest mountain peaks in the world. Sarah Doherty is one of them, and she’s done it on one leg.

At 13, Doherty lost her leg after she was hit by a drunk driver. While the tragic accident may have taken away a limb, it didn’t take away her spirit.

“I was determined that even though I had lost my leg, I would not lose my freedom,” she said.
She walked 720 kilometres on the Camino de Santiago trail in Spain, became the first amputee without an artificial limb to climb Mt. Rainier (1984) and the highest peak in North America, Mt. McKinley (1985). Her latest feat was summiting 18,000 feet up Mt. Kilimanjaro in Tanzania in 2009.

As an occupational therapist, Doherty customized her equipment to continue her active lifestyle.

This led to the invention of SideStix. Designed by herself and her partner Kerith Perreur-Lloyd, SideStix is the first modular sports crutch outfitted with a shock absorption system and attachable feet for a variety of terrains.

“I wanted to prevent long-term joint injury and also be able to access places in this world that aren’t accessible with crutches,” said Doherty. “I invented something with my partner to allow me to get out to the backwoods, be able to get into the mountains to climb and on the West Coast Trail to hike.”

Compared to traditional crutches that put pressure on shoulder joints, SideStix are designed as forearm crutches. Combined with a damper system, they reduce the pressure on the user’s joints by 40 per cent.
“When you compress the shock system down, it slowly releases up—similar to the joints in your body,” explained Doherty. It also has a ball-and-socket foot joint that mimics the movement of the ankle joint, lessening the impact at the base of the crutch tip. It can be customized for different activities with feet attachments for snowshoeing, sandshoeing and hiking.

To make SideStix an innovative product, Doherty goes above and beyond what’s expected in field testing.
“One of the best things you could do as a field tester is to push the limits of the product and that’s often pushing your own personal limits,” she said. She did one field test by climbing Mt. Kilimanjaro, the highest peak in Africa. Although one crutch broke close to the summit, it was a learning experience that further improved the product before SideStix was launched earlier this year.

Materials like aircraft aluminum and stainless steel make the crutches very durable. “I’m still using my original pair (that was made) seven years ago,” Doherty said.

A quick release mechanism for the foot attachment has recently been developed. Machiel van der Loos, a mechanical engineering associate professor, supervised a team of UBC engineering students with this project.

This innovation will allow users to easily exchange feet attachments without the use of any tools.

“There are a lot of crutches out there that are great for the regular run-of-the-mill use, but this’ll make it possible for people who need a crutch for whatever reason, either an amputation or a sports injury, to get back out doing sports in nature,” said van der Loos. The collaboration with Doherty is great, he added. “Because she’s an amputee herself, she knows intimately the needs of a high performance crutch. The enthusiasm that she has is both infectious to me as well as to the students.”

Where does this attitude and determination come from? “I think if you’ve had something taken away from you and you can return back to an active life, I think you are more grateful,” she said. “And I think that’s gotten me so that I do appreciate being able to go outdoors more than I think I could have if I hadn’t lost my leg.”

To purchase or to learn more, visit www.sidestix.com.