The knee has four main ligaments that work together to provide strength and stability during various back-and-forth and side-to-side motions.

* Anterior cruciate ligament (ACL)
* Posterior cruciate ligament (PCL)
* Medial collateral ligament (MCL)
* Lateral collateral ligament (LCL)


Ligament injuries, particularly to the ACL and MCL, are not a rare occurrence among athletes. When any part of the knee is forcibly overextended due to traumatic impact to the joint or an awkward landing during activity, the ligaments can fail to adequately support the motion. When pressed beyond capacity, ligaments can be strained and torn. The MCL Medial Collateral Ligament is a ligament that provides stability to the inner knee whereas the ACL controls forward movement and rotation of the shin bone from the centre of the knee. ACL and MCL tears are the most common knee injuries during sports or activities that involve twisting, bending and quick change of direction.


Your physiotherapist may show you some stretches that you can do at home to help keep your leg flexible. They may also recommend low-impact exercise, such as swimming for fitness or cycling. These types of activities will improve your muscle strength without placing too much weight on your knee. You should avoid any sports or activities that involve twisting, turning or jumping.