Your knee joint is held together by four ligaments:
If any of these ligaments are torn, injured, or otherwise damaged, you may feel pain and instability in your knee.
Athletes are more likely than the average non-athlete person to sustain an injury to their MCL or PCL due to the way their bodies move while playing sports and being active. MCL and PCL injuries are caused by traumatic injuries such as a twisting injury, a fall with force, or excess force on the knee joint.
The PCL is approximately two inches long. It’s purpose is to connect the tibia (shinbone) at back of your knee to your femur. As a result, the PCL limits the tibia’s ability to move backward.
A PCL tear can result from overextending or twisting your knee. This type of knee injury will leave your knee unstable and possibly unable to support your weight without significant pain or struggle.