WPI Engineers Invent New-concept Shoes to Reduce Injuries
A team of student engineers at Worcester Polytechnic Institute (WPI) has developed technologies for new sports shoe soles designed to reduce incidences of non-contact knee and ankle injuries. This is in response to a large number of ankle and knee injuries—notably to the knee’s anterior cruciate ligament (ACL). No athletic shoes on the market today offer this.
These shoes work by limiting loads transmitted through the soles to ankles and knees, where many injuries occur. “The idea is that work from a potentially injurious incident where someone might be landing, stopping or cutting would be absorbed by deforming elements in shoe soles instead of tearing an ACL or spraining an ankle,” said Christopher Brown, professor of mechanical engineering and inventor, who guides the student teams.
These technologies are based on tunable, nonlinear springs, aka SmartSpringTM . These springs provide special interfaces that transfer loads effectively and efficiently from both vertical and horizontal movement to a limit corresponding to regular play. Past this limit the springs adsorb without increasing loads, staying below thresholds that could cause injuries. The shoes recover their initial configuration between steps, and users may not notice that their shoe has responded to a potentially dangerous situation. According to the Journal of Athletic Training, the knee joint is the “…second most commonly injured body site after the ankle and the leading cause of sports-related injuries,” with more than 43,000 injuries occurring in high school athletes each year in a recent five-year period.
Researchers say the most common causes of ACL injury are landing from a jump, decelerating, and planting and pivoting off a foot.
Initially conceived by Professor Brown after learning about the epidemic in soccer and basketball injuries from Sokolove’s 2009 book, Warrior Girls: Protecting Our Daughters Against the Injury Epidemic in Women’s Sports. He based initial concepts on pioneering research he participated in on ski bindings in Vermont, Switzerland, and WPI. In 2012 a senior engineering design thesis team chose to work on this. They proved the concept in WPI’s Biomechanical Engineering Lab and filed a provisional patent application in 2013 a utility patent was granted in 2017.
A NY-based company, Sports Engineering, Inc. (SEI) licensed this technology from WPI in 2017 and has sponsored about 50 mechanical and biomedical engineering students led by Professor Brown. WPI student teams together with SEI further developed and continued to file patents creating the SmartSprings™ and SplitSole™ suite of technologies to mitigate horizontal shear and rotational loads. SEI and WPI’s innovative technologies use engineered, non-linear springs to avoid loads that can cause injury, while transmitting performance loads with high fidelity. Injuries can occur when loads exceed those required for ordinary performance. Limiting loads to levels required for performance can reduce injuries without diminishing athletic performance.
WPI and SEI intend to make and test additional prototypes this summer
SEI CEO Ed Cowle stated “This is the first time that horizontal sheer has been successfully addressed for athletic shoes. Professor Brown and his students have accomplished what none of the major footwear research and development departments have been able to.
Though there has been interest from major athletic brands, SEI will not begin marketing until more prototype testing is completed. The goal is to license technology and intellectual property to major footwear brands.
According to Prof. Brown “With these technologies, athletes will play safer and better. People will stay active longer and enjoy faster rehabilitation. Working on your feet will be more productive, comfortable, and less stressful. Everyone will feel better and safer walking, hiking, running, and playing sports with SmartSpring™ integrated into their shoe and boot soles.”
Undergraduate and graduate student project teams at WPI continue to develop technologies using nonlinear spring systems to promote safer, healthier shoes, helmets, skates, and other equipment for protecting the welfare of an active public, and for keeping an aging public active. Several patents have been granted, some are pending, and more patent applications for these technologies are being prepared.
About Sports Engineering Inc.: Sports Engineering Inc. (SEI) is a private company dedicated to the development and commercialization of injury preventive athletic footwear, sports equipment and products for health and well-being. Our SmartSpring technology suite is designed to help prevent injury to the lower leg while promoting healthier play and continued training by mitigating shear and rotational forces that might otherwise cause injury to the knees and ankles.