One of my favorite exercises on the planet targets the thoracic spine and shoulder.
When done correctly, this exercise improves range of motion for shoulder flexion and thoracic spinal extension.
What you need: high density foam roller and KB
Set Up: Lay down on your back with your feet and bent knees together. Feet flat on the floor. Position the foam roller across your spine (horizontally) between your T8 and T9 vertebrae. I chose this placement on the spine because this is where many sedentary people begin to see postural issues come up. Place the KB above your head as high as possible while still being able to grab on with both hands. Keep your hips up in the air, place your hands on the sides of the KB handle with your arms at near full extension and shoulder flexion. This is your starting position.
Execution: Breath in through your nose, tighten your core and maintain a neutral spine. As your exhale, drop your hips to the floor while maintaining a neutral spine. You will feel a strong pull in your abs and shoulders while feeling increased pressure on your thoracic spine. Relax back into the starting position. Do this five times in a row, then move the foam roller between your T7 and T8 vertebrae. Repeat five times, and move the foam roller between your T6 and T7 vertebrae. Repeat five times. You will be feeling more mobile and loose through your mid to upper back and shoulders immediately.