The ACL can be torn when the tibia is stressed suddenly in relation to the femur.
The ACL may also be injured when cutting to the same side as in this image.
In this YouTube video, Michael Owen of the UK suffers a rupture of his cruciate ligament (2006) as his right knee contacts the ball. The angle of impact has caused a twisting movement of his lower leg.
Less frequently, the ACL is injured in a contact injury. Here you can see two types of contact injury - both of which can injure the ACL. On the left the knee is forcibly hyper-extended, and on the right the knee is forcibly hyper-flexed.
Watch this tackle on YouTube, and the man who rolls head-over-heels (red shirt).