My knee is messed up.. I think I have excess liquid in it, but have not been bothered to do anything about it.
I cycle all the time, and its when I run it just seems as if there isn't much cartilage in my joints and nothing to cushion my bones and it really hurts.. I'm ONLY 17 lol.
Also, playing football last night (after I got going, my knees were ok) I got kicked in the little bone bit below my knee cap.. soo much pain from a little knock I couldn't walk properly. When I woke up this morning I couldn't bend it at all.. but once I got moving I was ok.