The recent leg injuries suffered by star athletes such as the Warriors’ Kevin Durant (torn Achilles) and Klay Thompson (torn ACL), and Duke’s Zion Williamson (knee sprain) have all occurred when their feet have pushed off against the hardwood of the basketball court.
All three could perhaps have avoided those significant injuries through a commercial offshoot from the research labs of Worcester Polytechnic Institute. Sports Engineering, Inc. is endeavoring to mitigate injury risk in athletes by reinforcing the key point of contact between athlete and floor: the sneaker. SEI’s SmartSpring technology is based on work by mechanical engineering professor Chris Brown and his students.
SEI has so far created an early prototype, and has plans for an advanced version to be ready for further testing later this year. The sole of the shoe features adjoined circular springs made of flexible polymer—dubbed the “goat’s head” both for its shape and for WPI’s mascot. The springs will remain rigid and transmit force for athletic performance up until a certain point. When the force reaches a potentially injurious threshold, the springs then begin to absorb it instead.
“You can store the energy in the spring at a constant rate as opposed to an increasing rate,” Brown said, adding: “The shoe recovers before you can put your foot down again, so it’s back into its original configuration. And the player might not even know that they’ve been protected by the shoe.”
Brown was an All-American skier at the University of Vermont in the 1970s. His racing experience informed his post-doc engineering research in the materials department at the Swiss Federal Institute of Technology. Among his endeavors there was a project that culminated in a presentation to the International Society for Skiing Safety in 1983 about how to prevent ACL injuries in skiers.
His efforts to improve the materials and function of ski bindings have been a focus for 40 years, but earlier this decade he began to learn about the high rate of ACL tears—particularly among young women—in sports such as basketball and soccer. This piqued Brown’s professional interest at WPI. In 2013, the Journal of Athletic Training identified knees and ankles as the two most common injured areas in athletes.
“Unlike ski bindings which release and can leave you out of control at 60 miles an hour, when the shoe starts to respond, it’ll be absorbing the loads that might otherwise cause injury, but you can continue what you were doing,” Brown said.
WPI requires students to complete a capstone project, and Brown suggested his idea to a few students back in 2012. What they created was raw but had potential, said SEI CEO Ed Cowle, an entrepreneur who has licensed several technologies from universities. Cowle raised money and assembled other business, design, and engineering professionals to assist in continued development. Several WPI students remain involved in the project.
“In sports shoes, innovations have really been, I think, quite few over the years,” said SEI president Bob Daniels, who added: “Nothing that’s really been focused on injury prevention in any significant manner. I think Chris and his team have been the first to really address this in a major way.”
SEI also envisions applications beyond elite sports. Athletes at all levels could benefit, from Little Leaguers to recreational hikers to seniors playing tennis. The shoe springs can also be tuned to trigger activation at different force levels, which could benefit rehabbing athletes in particular, since they may be regaining the ability to withstand loading.