Have you ever heard the pop of a severe ankle sprain, even if it wasn’t your own ankle? Sprains can be painful, serious injuries. Simple bone fractures usually heal in about six weeks, but severely sprained ligaments can take six months or even longer to heal completely. Healed broken bones typically regain their original strength, but sprained ligaments may never get back to their full strength. Passive methods such as braces and tape can help prevent ankle injury and assist during rehab, but passive methods have drawbacks. A team of engineering and medical researchers at Arizona State University (ASU) are developing a smart shoe that integrates an active ankle support system that promotes healing.

ASU’s Smart User-Effective Data-Enabled (SUEDE) Shoe dynamically adjusts the stiffness of its soft brace ankle support as the wearer moves about. Non-active support systems such as passive braces and tape often restrict natural motion. Patients may rely on the braces rather than regain strength and confidence to walk or run without support. The SUEDE Shoe integrates sensor data processing, smart actuation, biochemical modeling, and injury prediction to control tightening and ankle support as needed. Machine learning plays a vital role in processing sensor data accurately and quickly to adjust the shoe’s support level in real-time.

“Ankle biomechanics is a prime example of a complex dynamical system, where many important parameters are not directly observed. Machine-learning-based approaches can help bridge those gaps,” Pavan Turaga said in an ASU news release. Turaga is an ASU professor and director of the School of Arts, Media, and Engineering.

A multi-disciplinary ASU team continues to develop the SUEDE Shoe in a four-year project. The team works with orthopedic surgeons and physical therapists for input on foot and ankle mechanics and to evaluate the smart shoe’s performance. One of the project goals is learning more about the injury risk and prevention in various activities and sports.