My leg stays on through thick and thin (and yes, I am talking about stump size variation, not adversity) because I have a really great belt holding it on. I don't know whether to call it a "silesian" belt or a "suspension" belt; I don't know the difference. What I used to have was a nasty thing, a prototype of something my prosthetist's company was developing made out of thick velcro attached to hard white nylon fabric which sliced my flesh open at the edges and didn't stay up over even my generously rounded hips. (And seriously, is there anything that can make you feel quite as attractive as constantly reaching into your pants to pull up the belt holding your leg on?)
What I have now is another design my prosthetist and his company worked on, and you can see it here:
I am here to tell you, this thing is the greatest thing since sliced bread -- or it would be if sliced bread had anything to do with holding on prosthetic limbs. Its ergonomically padded portion with a side softly textured for traction stays where you put it against your skin or underwear, but it's cushy, flexible and not at all rough, so it does it without discomfort.
It does not cut or chafe. It stays in place. It seems to be hypoallergenic. It's absolutely no bigger or heavier than it has to be. And yet, it holds my leg on. No bother, no fuss, total reliability, total comfort, and it comes in my size. What's not to like?