Back Of Knee Pain More Condition_symptoms I Have Severe Knee Pain In The Back Of My Knee, What Is Hurt?

I have severe knee pain in the back of my knee, what is hurt? - back of knee pain more condition_symptoms

I was playing basketball about 2 months and pain, without knowing it, to have the next day when I sit or I bend a sharp pain in the joints on the back of the knee, sometimes did i hurt her, he almost fell, this could his problem? What kind of injury that I have?