A 3-year prospective study was initiated to evaluate torsional resistance of modern football cleat designs and the incidence of surgically documented anterior cruciate ligament tears in high school football players wearing different cleat types. We compared four styles of football shoes and evaluated the incidence of anterior cruciate ligament tears among 3119 high school football players during the 1989 to 1991 competitive seasons. The four cleat designs were 1) Edge, longer irregular cleats placed at the peripheral margin of the sole with a number of smaller pointed cleats positioned interiorly (number of players wearing this shoe, 2231); 2) Flat, cleats on the forefoot are the same height, shape, and diameter, such as found on the soccer-style shoe (N = 832); 3) Screw-in, seven screw-in cleats of 0.5 inch height and 0.5 inch diameter (N = 46); and 4) Pivot disk, a 10-cm circular edge is on the sole of the forefoot, with one 0.5-inch cleat in the center (N = 10). The results showed that the Edge design produced significantly higher torsional resistance than the other designs (P < 0.05) and was associated with a significantly higher anterior cruciate ligament injury rate (0.017%) than the other three designs combined (0.005%).