Seated on a Chair, place hands behind your head to support your head. Position yourself so your mid back, where you feel restricted is at the top of the Chair and lean back, hinging over the top of the Chair. Take a couple deep breaths. Adjust as you need to. You can also do this laying on the floor over a Foam Roller or even a pillow for a more gentle option. See the pictures using a Foam Roller or Mobility Band.