아 저게 신전 자세인가요? 저도 목 아프면 앉아서 뒤로 젖히거든요
When you have neck pain, adopt a new posture!

I have a severe pain in my neck, so I tried various things, took medicine, and also underwent physical therapy.
I think the pillow is also a problem, so I changed the pillow several times.
Then I went to the orthopedic department and took a picture out of curiosity, and they said I have straight neck.
They said it's because of a straight neck, and the muscles are pressing and causing pain.
So, from that day on, I searched very diligently for forward neck stretching exercises.
Then I happened to see something called "Shin Electronic Age," and it's not difficult, so I can easily follow along.
Type "Shin Jeon Jae" on YouTube. It's very simple, and the more you do it, the more you can feel the pain disappearing.