This is often a completely common and normal finding we see after the 1st few times you use a new cervical support neck pillow, such as the cervical linear traction neck pillow. If your spine has no curvature or you are not used to using a pillow with good neck support this will often happen because it is something totally new for your body. Using the traction side of the cervical traction neck pillow can cause mild soreness in the neck for some patients, and therefore it is often recommended that the support side of the pillow be used.
The soreness will be a muscle spasm, sort of similar to if you went to the gym and worked out for the 1st time in a while. Use ice to relax and calm any soreness if you like. But for the most part, this soreness will dissipate as you get used to the new contours of your new pillow.
We often recommend using a new cervical support pillow for a short period of time gradually working up to using it all night. This will eliminate any chances of soreness.
On the other hand some people take to the pillow right away and do not experience any muscle soreness. Either way it is completely normal. The cervical linear traction neck pillow is the most popular on Arc4life.com and 9/10 people love it and swear by it.