I'll never have a hip replacement, as I really don't know how people manage. I'm almost constantly turning from side to front to other side (and waking up doing it) all night.
I can't lie, or sleep, on my dodgy back at all. When it's real agony, I use satin sheets to make the moving easier.
I've always fidgeted, too alert. Having my wisdom teeth out in hospital, aged 20, I was throwing myself about and vomiting, with a splitting headache, after my pre-med.
A whole troop of worried doctors appeared and checked me over - then said 'You're just fighting it!' (one told me never to have a pre-med again). Same again with Pethidine (1st child) and with second ('We'll just give you a half dose.')
If I'm in a lot of pain, I can nap briefly in a chair, with a plank and pillows on it's arms in front of me - but sitting is painful too.