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Stories: Amputee climbs Africa’s highest peak

Sarah Doherty tests high-tech sports crutches developed at Bloorview

With one leg, high-tech crutches, and an anything-is-possible attitude, Sarah Doherty has climbed Africa’s highest peak.

Last week, the Canadian occupational therapist – who lost her right leg at age 13 when she was hit by a drunk driver while riding her bike – made it just shy of the summit of the 19,340-ft. Mount Kilimanjaro in Tanzania using shock-absorbent crutches she developed with Bloorview prototypist Bill Johnson.

Called SideStix, the aluminum crutches have a built-in, spring and oil-damper system that absorbs impact on the upper body, reducing joint compression by 40 per cent.

“I was determined that even though I lost my leg, I wouldn’t lose my freedom,” says Sarah, who lives on the Sunshine Coast of British Columbia. “Because I’m such a high amputee it’s been difficult to wear a prosthetic device. The current crutch is very primitive, and my goal is to introduce technology into it and open the door to recreation and sports for people like me.”

Typical crutches are hard on the joints “because your arms aren’t made to walk like your legs and don’t have the same muscle structure or joint cushions,” Sarah says.

For years Sarah has been adapting crutches to create a smoother ride. Last year she met Bill Johnson at a seating conference in Vancouver and hired the Bloorview machinist to produce the most recent SideStix prototype.

The main benefit is a more sophisticated shock system. It was Bill’s idea to combine a spring and an expansion oil damper in the crutches so that the initial impact is absorbed by the spring compressing, and the damper then slows the spring’s expansion. “It slowly uncoils like your joints do, giving a nice cushion in each step instead of jarring your joints,” Sarah says.

The prototype includes attachable feet that are suitable for city or wilderness terrains.

“The first is a round snow shoe made of an aluminum ring, mesh and a centre spike; the second is a hiking foot with metal cleats for mud and ice; and the third is a foot with a rubber tread for use on standard tile and pavement,” Bill says. Bill added a ball-joint in the heel to allow the feet to rotate. Sarah wore the cleats for most of her recent climb.

She wanted to test the crutches on Mount Kilimanjaro because “you travel through four ecological zones – rainforest, moorlands, alpine desert and arctic conditions – and each terrain is different,” she says.

In general, the Sidestix worked well: “I had no joint problems, no blisters, and the feet were solid and didn’t slip,” Sarah says.

Unfortunately, on her final climb to the summit, her left crutch snapped and broke above the handle. While her partner descended to the Kibo Camp to try to repair it, she continued up. For two-and-a-half hours she hopped on one foot, using her other crutch and her guide’s arm for support. The crutch was repaired and on two crutches she reached Gilman’s Point, just shy of the summit. Park regulations prevented her from climbing to the highest point of the volcano’s rim at that time of day.

The SideStix shock-absorbing system has a potentially large market. In addition to crutches, it can be modified to cushion the gait of people who use alpine walking sticks, canes and walkers.

Sarah, who works as an occupational therapist with preschoolers who have disabilities, already has clients with spina bifida and cerebral palsy who could benefit.

She says her dream of bringing the crutch into the 21st century was inspired by Marilyn Hamilton, who she trained with on the U.S. Adaptive Ski Team years ago. “She invented the Quickie wheelchair, a sports chair that opened up the world of wheelchair basketball and tennis and made wheelchairs cool. I think the time has come for crutches.”

In addition to shock absorbers and attachable feet, Sidestix are ergonomically designed “so that you’re weight bearing on the meaty, pinky side of your hand, similar to the way shoes are designed,” Sarah says.

Sarah has patented the technology – with Bill listed as a co-inventor. She hopes to find an investor interested in bringing SideStix to market.

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