Ok, i used to be able to do an aerial a few months ago (in May-June) . But at the end of June when i tried an aerial at my friends house, my knee cramped for some reason, and it was really sore. The pain calmed down after 2 minutes or so, and me being silly, decided to try again. The same thing happened. (It was my muscle on the left of my left knee). After that i stopped doing aerials, but whenever i tried a back handspring, i was fine. So after Summer (i didn't do it all summer) i was doing a leg kick and my knee muscle cramped again. Whenever i try a leg kick after that i''m fine. I really want to try my aerial again but i am scared of my knee cramping (it is REALLY sore when it happens). I have flat feet, does that have anything to do with it? Thank you SOOOOO much for your time, if you have any suggestions as to what might be causing it please reply. Thanks x