Hi Hunn, there isn’t much difference between 460 and 525 it’s about a third of a cup size. I got 345/385 and it’s given me back ache as I am prone to them anyway. I’m exercising to strengthen my core muscles hopefully that will help but to be honest if your backs going to hurt it’ll hurt regardless of wether you get 460 or 525 Hunn. Your best off doing core strength building excersises now (you can google excersises for a bad back) and that’ll hopefully prevent it x