I exercise regularly and play in soccer/basketball leagues. When I'm active my right knee has no pain at all. If I take some time off and am rather inactive for a couple days, the inside (my left if I'm looking down at it) of my right knee gets very sore/tight. It hurts to go from being bent to extended, almost like it isn't suppose to extend. To describe where the pain is, if you are looking at the knee cap from the front, it is in the Northeast corner, but not on the cap itself but instead the muscles/tendons (I don't know what the hell is there) above. It is visibly swollen, when the swollen area is pushed on it is very soft.
Any advice is appreciated.