Thoracic Extension
The thoracic spine is composed of 12 vertebrae of your upper back, ranging from your mid-back up to the line of your shoulders. Tightness or weakness in this area can cause pain, slumped posture, and discomfort with sitting and standing. If you are noticing a rounding of your upper back, then you may need to incorporate a thoracic strengthening exercise.
Thoracic extension can be done anywhere you have a good chair with a low back. While seated, clasp your hands behind your head with elbows wide. Slowly lean back over the edge of the chair, extending your upper back. When you've reached a position in which you can feel a stretch but no pain, tilt your chin up toward the ceiling. Inhale and exhale slowly, return to upright position, then repeat 5 to 10 times.