After playing a tournament I noticed that the outside of my left knee was hurting. I thought it might be just overuse so I left it alone. Currently I still train and play but the pain still hasn't gone away. When I run or walk straight its fine, but say if I was sitting with my foot flat on the ground and i let my tilt to the outside it hurts. Same when I'm turning. Any reasons why the outside side of my knee would hurt?