Most of the time I am using two hands; hold my Max in my left hand, and use my right index finger to swipe. This feels much more natural to me than trying to use my thumb. The Max just isn't very one-hand friendly. If I am using one hand I have the phone trapped against my chest and I do have to contort my thumb, but I don't use it like this unless I have no other choice. Hardly ever, so this really isn't an issue for me. You're doing it wrong.