In the world of sports, few conditions are as debilitating as getting your knee torn–in three places all at once. Dubbed the “unhappy triad” by the father of sports science Don O’Donoghue in the 1950s, this type of knee injury commonly occurs in sports with rough contact, like rugby or football, and sports that require a significant amount of pivoting on your knees, like soccer or basketball. Around 25% of athletes who sustain knee injuries suffer from the unhappy triad.