I fell of a lift 5 ft in the air and landed on my left leg, I had an xray of my knee and was told it was a bad contusion. I was on crutches and wore a knee brace for 3-4 weeks but was released to light duty after one day. I have alot of pain in my knee, sometimes it feels like it will pop out of place if I put too much pressure or turn to quickly. What if anything could be wrong with my knee?