My daughter started working out, taking a class 3 times a week, about a month ago. The night before last the class got down on hands and knees, when she did that both knees popped. She has had trouble with her left knee in the past, but in her right knee, there is now a dimple, near the bottom of the knee cap. But she has no pain. She is 29, weighs about 180 and is 6 1