I have no idea what's wrong with them. If I squat without weights (body squat) at about 1/4 down (right before knee level they hurt. (right under the cap) Stairs hurt me a lot, as well as bikes. They had completely stopped hurting (I thought because I started squatting) i was so happy since we have stairs. The past week or so it has started up again and I'm just tired of it. It's primarily the right one, left one not so much.