When ever I'm at dance class (Usually doing contemporary or modern) when I'm on the ground and my legs have to be bent as close to me as possible and I have to roll on the ground, sometimes my knee suddenly Pops and I have to straighten my leg very quickly otherwise it will be severely painful to do anything. Even after I've straightened my leg, it'll still hurt for about 5 minutes after and it'll still hurt 10 minutes after the pop, when i bend it. Please help me because I often have to get up and stop dancing. this will be a big problem if I'm performing and it happens. It never happens during ballet though. It can be either of my knees, it matters which way i'm rolling