A high percentage of injuries to the anterior cruciate ligament (ACL) occurs in athletes  A sophisticated statistical analysis looked at the number of athletes who suffered an ACL injury, and assigned numerical values to both the nature of the stress that produced the injury and to the resultant level of damage to the ACL
Researchers expected that, controlling for level of injury-causing stress, all athletically inclined individuals would show similar tendency toward ACL injury regardless of the specific sport
gymnasts are often given credit for inventing new positions or moves, while football players far more regularly follow the typical moves associated with their position.