Good day I was in a bad motorcycle accident 2008 back home in South Africa but only now I have problems with my knees. Sounds like popping popcorn when I bend them and is very pain full. I haven t been to see a doctor as I am scared for what he might find. I do believe I have a pinched nerve in my lower back since the accident. I get shooting pains from my lower back in to my knee and then down to my ankle. Very pain full. Can you maybe give me a possible diagnosis?