I have been sleeping with a cylindrical pillow to prevent cervical spondylosis. Recently, there is a slight pain in the shoulder behind the neck, as shown in the picture. What happened?

It is a mild pain symptom caused by six joints of your cervical vertebra dislocated backward by an inappropriate pillow. 1, adjust the height of the pillow to about 8 cm. 2. Sleeping in the lateral position makes the cervical spine and shoulders at 90 degrees. 2, you can use your four fingers to pull the six joints of the cervical spine and push it forward. You always feel that the pain in the cervical spine is gone, and the symptoms of slight pain completely disappear. Do it on both sides of the cervical spine. Don't need any medicine.