This video demonstrates how to increase the upper back flexibility by using a towel. This exercise is suited for someone with a very stiff upper back.
Caution: If you experience discomfort during this exercise, you can decrease the duration and decrease the height of the towel. If you have a very stiff upper back and your head does not touch the floor, you may place a thin pillow underneath your head for support until your upper back becomes more flexible. If the discomfort persists, stop the exercise and consult with your health practitioner.
Awesome! that worked feels great!