How do you stretch the knee?

The medial collateral ligament (MCL) along with 3 other ligaments (ACL, PCL, LCL) aid in the stability of the knee joint. More specifically, the MCL resists widening of the inside of the joint. Stretching or tearing of the MCL will result in injury. A tight MCL is a result of over stretching. The best thing to do is ice it and rest.