Another big key to ACL injury prevention is single leg strength. More specifically a type of strength we refer to as single leg unsupported. The clip below demonstrates a single leg squat. We refer to this as an “unsupported” exercise as the back foot is not in contact with the floor, bench etc. The key to unsupported exercise is that the muscles that stabilize the pelvis behave differently in a true single leg stance. This is essential for injury prevention and for rehab, in fact this is our “return to play” standard. If you can’t perform this exercise. regardless of your size or gender, you are not strong enough to return to play.
This is an advanced version of the the one leg squat that adds an element of instability via and Airex pad. The Airex pad increases the demand on the hip stabilizers, particularly in the frontal plane.
The progressions can be found at
Michael Boyle's Strengthcoach.com Blog 