Women who get a prosthetic foot after losing a leg to disease or injury have limited shoe options, but an invention by five Johns Hopkins University students may change that. The university announced Wednesday that the “Prominence” could be the first non-custom prosthetic foot to adapt to high heels up to 4 inches high.
“High heels have become an integral part of the female lifestyle in modern society, permeating through all aspects of life— professional and social,” the mechanical engineering students wrote in a report of their project. “For female veterans of the U.S. armed services with lower limb amputations, that seemingly innocuous, but so pervasive, and decidedly feminine part of their lives is gone.”
Creating the ideal prosthetic proved challenging for the students, as the device needed to be easily adjustable for multiple shoe types, maintain its position without slipping, support a person weighing up to 250 pounds, weigh less than 3 pounds itself, and be slender enough to accommodate a woman’s shoe.
Students developed their project in two semesters by evaluating its function with mathematical equations, as well as with tests by machines and people, according to the release. After trying multiple options— including a mousetrap spring and balloon— the team settled on a 28-layer carbon fiber footplate to form the base of the foot as it best gave the foot the spring it needed at the proper weight.
The final device also uses a heel adjustment mechanism with two interlocking aluminum disks that opens and closes using an attached lever at the ankle.
Alexandra Capellini, a Johns Hopkins University junior studying public health, lost her right leg to bone cancer and was one of seven participants for the prosthetic test, which involved four types of women’s shoes.
“An adjustable ankle is useful in contexts even beyond high heels,” Capellini said in the release. “Ballet flats, sneakers, boots, and high heels especially, all vary in height, so an adjustable ankle opens up opportunities to wear a variety of shoes.”
The team hopes their design will help the nearly 2,100 American women who lost a leg or foot in military service, as well as other women who have suffered from lower-body limb losses and want to wear high heels again.
“I think the final prototype produced showed the way forward,” Nathan Scott, a senior mechanical engineering lecturer at Johns Hopkins University who advised the student group, said in the release. “As usual we just need to go around the design and prototyping loop one more time.”