What is the ACL?
Anterior Cruciate Ligament (ACL) is one of the four ligaments in the knee joint (orthoinfo2017)
The ACL runs diagonally inside the knee like a rope to make the joint stable. The ACL keeps the knee stable when changing directions quickly or when landing from a jump.
HOW IS THE LIGAMENT INJURED?
Changing direction with the knee caving in
Planting and twisting your foot
Poor landing technique from a jump
Being hit on the knee from the front or the side