Risk of Anterior Cruciate Ligament Injury as a Function of Type of Playing Surface

Since its introduction in the United States in the 1960s, artificial playing surfaces have been implicated as a contributing cause to ACL injuries. A variety of design factors have been hypothesized to play a role, including surface hardness, rotational stiffness, and release torque. These physical characteristics may interact with other environmental factors such as cleat design, surface moisture levels, and ambient temperature. Partially in response to these concerns, manufacturers have continued to refine these products to bring their physical characteristics closer in line to natural grass surfaces, but concerns among players, medical personnel, and the public persist. Multiple clinical studies and injury surveillance efforts have been conducted at the amateur and professional levels in a variety of sports. These results of these studies have been mixed. To date, the strongest evidence for increased ACL injury rates on artificial surfaces comes in football, where players are bigger, and the forces generated at the shoe-surface interface much larger. However, the large number of potentially confounding variables in such studies makes it difficult to conclusively implicate artificial surfaces in higher rates of ACL injuries.