Courtesy of Giovanna Nigro Chacon

Van Philips
Coming up with a new idea for artificial limbs isn’t easy. Limb design changed very little during the past 200 years until Van Phillips set off a period of intense experimentation and change in the 1980s with his sprinter’s leg. Phillips’s innovative design was modeled after the leg of the cheetah, the fastest animal on the planet.

Many of the most creative prosthetic design ideas have come from prosthetic users who became frustrated with their options. D. W. Dorrance created the split-hook hand in 1912 to suit himself. James E. Hanger lost a leg during the Civil War and started his own company in order to supply serviceable legs to fellow veterans.

At the age of twenty-one, Phillips, an enthusiastic athlete, lost a foot when he fell from his water skis and was clipped by the boat’s outboard motor. Like Dorrance and Hanger, Phillips grew impatient with the heft and clumsiness of his prosthetic choices. He switched his college major to prosthetics and orthotics and imagined something really different. After a search for materials and discussions with colleagues, he designed a foot to suit his needs and started a company to supply others with the new device.

Phillips’s design, called the Flex-Foot, uses carbon fiber, already well-known in aeronautics because of its flexibility, strength, and light weight. As an athlete shifts weight onto the prosthesis, propulsive energy is stored and then released when the weight shifts to the other foot. The coil-like action pushes the athlete forward with each step, improving speed and efficiency

Flex-foot sketch, by Van Philips

C-Sprint drawing, by Hillary Pouchak