We recently a great question from an amazon customer recently. One that I want to share on our arc4life website:
Does this keep your head from falling to the side and stretching your neck when sleeping?
The Arc4life cervical traction neck pillow provides gentle neck stretching or traction when you sleep on the Traction V Side. You can either sleep on your back or you can just lay on your back on the traction V Side and set a timer to do 20-25 minutes of neck traction. Either way, you will be gently opening up the intervertral foramen in between each of the vertebra in your cervical spines - ie you will be opening up the spaces between the bones in your neck, allowing release of any impinged nerves.
If you do well with this type of gentle traction, consider getting yourself a proper neck traction unit. One example of this is the cervi-pedic traction unit: https://www.amazon.com/CerviPedic-Neck-Relief-Pillow-Relieves/dp/B00FSOUNSW/ (available on amazon).
Also, to answer your first question, yes, if you sleep on your back, the pillow will keep you in place.
Please make sure you order the best size possible based on your height and weight. Check the images for a basic sizing chart. Most people order the medium size and do very well with it. Also, we are here to answer any questions for you on how to use the pillow. There are a few ways to use the pillow. If you order a pillow that to big (or too small) you will not get the neck support or get too much (which may push your head too forward).
Finally, there may be an adjustment period to using the pillow for the first few times. If you are experiencing neck pain, a herniated disc, numbness and tingling, start with no more than 5-10 minutes. Then put the pillow away, and use your old pillow. Next night, sleep on the traction pillow for either 5-10 minutes or increase it by a little bit. Some neck soreness is normal.