Come into an all fours position on an exercise mat with your hands directly under shoulders and your knees directly under hips. Place a foam roller parallel to your right side, level with your torso. Gently lift your left hand from the floor, reach it under your torso and right arm and place it atop the middle of the foam roller with your palm facing up. This is your start position. Begin to rotate through your spine, pushing your left hand away from you and using the foam roller to assist the movement. Rotate your spine as far as you can without shifting your hips significantly. Slowly reverse the movement and return to the start position. Perform on both sides for the recommended amount of time (or reps).