Traction Enhancing Products Affect Maximum Torque at the Shoe-Floor Interface: A Potential Increased Risk of ACL Injury

The knee is one of the most frequently injured joints in the body, between 100 000 and 400 000 Anterior Cruciate Ligament (ACL) injuries occur in the United States each year. This investigation explores the impact of wipe- or spray-on sneaker products used to increase traction between shoes and hardwood courts on the loading of the ACL. Specifically, the maximum torque achieved prior to the sneaker slipping on the court surface is measured using a servo-hydraulic bi-axial load frame. A prosthetic foot fitted into a sneaker was fixed to the load cell and a piece of hardwood court was fixed to the actuator of the load frame. Axial loads were applied to simulate an athlete's body weight and torques were applied to simulate an athlete pivoting on a hardwood surface. The maximum torque achieved prior to the sneaker slipping on the hardwood surface was measured. The investigation finds that the application of the wipe- or spray-on sneaker products increases the maximum torque achieved prior to the sneaker slipping by 164%. This increase in torque exceeds prior published levels of torque that resulted in ACL failure in a cadaveric model.