When you put the pillow on the back of your head, you need to press it to a height of one or two centimeters. When you press on your neck, it's about ten centimeters away from the bed. You should maintain support. There is almost no elastic material at this level, only loose feathers and feathers can do it, and the filler has to be gathered to the neck when sleeping.
Different heights have different loads on the cervical spine, and the height of the pillow is not suitable, which will also cause damage to the cervical spine. A pillow that is too high for a long time is equivalent to passively lowering your head, which will cause great pressure on the cervical spine. Moreover, too low neck can not relax, which will destroy the normal physiological curvature of cervical spine.
Normal cervical vertebrae have a convex curvature. If the pillow can't fit the cervical vertebra, the curvature of the cervical vertebra will change after a long time, resulting in abnormality. Everyone's cervical curvature is different, so different cervical radians must be matched with pillows with different radians to fully support the cervical spine. Each of us should choose the height that suits us according to our own situation, with the neck slightly higher and the head slightly lower, so as to form the physiological curvature of the cervical spine that conforms to the normal human body.