I jumped about 8ft out of a barn window the other day. I landed with one knee bent normal, but near straight and the other went backwards. Though I could still walk, over the past week, it s been harder to walk. My knee feels like it is detached from my lower leg. When I lift my leg, feels like the lower part of my leg is dangling, but when straightened back out, the knee pops underneath the knee cap? What do you think I have done and what kind of doctor should I see about it?