Hmm. Yeah, padded socks might work... and yep, they're fully broken in, I think. I wonder if maybe I got the wrong size? I got size 9.5 .. I usually wear 9.5 or 10 in most shoes, but when I tried on some Chucks I needed a size 9. Perhaps I should've gone up to a 10... maybe the back wouldn't dig into my heel then. Dunno.