Good ergonomics apply in VR just as they do in any occupational setup. I was suffering from cervical lordosis before ever going into VR - but because I've used it to increase my range of motion throughout the day, and eliminate my need to ever hunch or squint, I'm feeling much better than before going full-time VR.
But: don't do it all at once. Work up to it, balance the weight appropriately, position screens properly, and take breaks! Yes, I do 8-10 hours a day in VR - but not all at once.