ACL

The ACL (aka anterior cruciate ligament) is a ligament, not a muscle. It’s inside the knee joint between your thigh bone and your shin bone, behind your knee cap. Cruciate is in the name because it crosses diagonally within the joint. Anterior is in the name to distinguish it from the posterior cruciate ligament. Its job is to help stabilize the knee, especially keeping the shin from sliding forward relative to the thigh. It also prevents rotation of the shin.

People often talk about the ACL in terms of injury. It’s the most commonly injured ligament in the knee. It gets injured when the movement that it stabilizes against becomes so quick or extreme that the ligament (and the muscles that help it) can’t overcome the movement. There are exercises you can do to prevent ACL injury.

Disclaimer: The information provided is for educational purposes only and does not take the place of medical advice.