I've been having some problems with my left knee the last couple of months. When I kneel, sit Indian style or bend my knee in anyway, it hurts to straighten it out. It was minor at first but now it's getting rather painful. As long as I stay standing, it's fine. I can run, jump, and everything without a problem. I play flag football once a week and never have a problem. It's just painful when straightening it out. I was hoping to avoid going to the doctor, but it's not getting any better. Any ideas what it could be?