Is it ok to sleep with a posture collar on
 

Is it ok to sleep with a posture collar on ?

I don't think so. Posture collars end up adding tension and stress to your muscles and vertebrae, and not only to those of the neck but all along your spine too. You should take rest from any device that forces you or any part of your body to keep a (partially) unnatural position, specially when it comes to such a delicate part as the neck and back. Wear the posture collar all throughout the day if you want, but remove it when you go to sleep (you can change it for a normal, thinner and more flexible collar)