They say that when a dog doesn't feel comfortable or safe that they'll curl up into a tight ball. When I first got Daisy that's how she was whenever she wasn't moving - always curled up - they also say it's a signal of past abuse. When we'd sleep in bed I'd sort of just surround my body around hers and over the months she just slowly started stretching out until now she sleeps fully extended. I think she's finally burned out her last bits of insecurity. And it's showing in every aspect of her life. She hasn't bitten another dog (and by biting I don't mean biting to hurt I mean nipping at the end of a lunge - if she actually bit dogs she'd be dead by now).
I thought I'd include a "before and after" picture - it's quite comical actually.
Daisy curled up in her chair
How Daisy takes a nap now...