Some people have tight muscles in their backs, not pinched so they are in pain but also not released do they won't cause pain. Because they are already tight the ac causes them to pull tighter to cause the pain you are having. So the tight muscles are in your upper back/neck area so you have to release the muscles that are in that area and the pains won't happen again because now the muscles are fully released, not poised to strike again as they were before. Here's how to release those muscles:
Put your hands alongside your head so your thumbs are on the front of the muscle under your ear and your fingers are on the back of the muscle behind your head. Squeeze your thumb and fingers together and hold. Relax your body. After 45 seconds, slowly lower your head as far as you can, release the pressure but hold your neck lowered for another 30 seconds.
(do from a sitting position)
Place your left hand on your left leg next to your body. Place your right hand over your left shoulder, fingers over the back and the palm in the front and firmly press on them and hold. After 30 seconds slowly lower your body forward and to the outside of your left leg, keeping your left arm fairly straight as you do. When you reach your lap remain there for another 10 seconds, release the pressure but rest there for another 30 seconds. Then reverse your hand positions and do your right side.
for best results relax your body first by taking a deep breath and exhaling then remain this relaxed.