Hi, I took a pretty hard fall 2 days ago rolling my right ankle, which is still very sore, but my real concern is my left knee. I smashed it pretty hard on the edge of the sidewalk, just under my knee cap. There is some swelling and a bruise, but I'm more concerned about the numbness. It feel very strange when I walk, as if it is someone else's knee, and deep pain when I apply pressure to the knee, but it is numb to the touch. What could be causing this? Should I go to the doctor?