How old are you?  Research has determined that girls from early to late puberty are at greater risk for ACL injury as they show decreased neuromuscular control of the knee with landing from a jump movement.  (Hewett et al. JB&JS, 2004)   Does your sport require jumping?  A recent study estimated that 70% of all ACL injuries occur when landing from a jump.  (Boden et al. Orthopedics, 2000)   Do your knees cave in when landing from a jump or when cutting?   Excessive knee valgus (knees coming together) can be a cause for ACL injury.   Do you have a dominant leg that you use with your sport?  Research has determined that the dominant leg has a greater valgus knee when landing from a jump. (Ford et al.  ACSM, 2003)   Are your hamstrings weak?  The hamstrings act as a dynamic restraint to ACL injury.  Most athletes display a significant overdevelopment of the quads compared to the hamstrings.   Are your other joints loose?  Hypermobility (laxity) of your other joints may be   a precursor for ACL injury.  Check the mobility of your knee, elbow, and pinky  finger.   Can you balance on one leg?  If you have to touch down with the other foot or your knee caves in you are at a greater risk for ACL injury.  ACL injuries often occur when landing on one leg or cutting on one leg.  The athlete needs to dynamically stabilize the knee effectively to prepare for an injury free season.   Can you land a jump softly?  If you land a jump from a 12-18 inch box with a loud thump, you are having difficulty decreasing the forces of landing—increasing your risk for ACL injuries.