The knee joint contains 4 main ligaments that provide support and stability to the knee, and limit its movement. One of the ligaments is the PCL, located more towards the back of the knee. A PCL sprain describes the partial to complete disruption of the PCL, which is much less common than other knee ligament sprains. A forceful hyperflexion or hyperextension of the knee can potentially cause a PCL sprain. Individuals involved in a motor vehicle accident may sprain their PCL. Many patients are able to walk immediately after the injury and may not even know that they have a PCL sprain. Although complete recovery is not expected, 90% return of function can be expected.