Thoracic crunches on a foam roller increase mobility of the spine while strengthening the core.
Lie back on a foam roller, placing it right below your shoulder blades. Place your hands behind your head and flare your elbows out the sides. Knees should be bent and feet firmly planted on floor. This is your starting position.
Contract your abs and crunch up. Pause and slowly return back to starting position.
Avoid performing the movement too quickly. Do not bounce on the roller.