The Complete Foam Roller Set consists of all Neck Shaper Rolls and all Back Shaper Rolls. The Neck and Back Shaper rolls come in a variety of diameter sizes and densities (Soft, Medium, Hard). You should increase the diameter and density of the rolls over time to improve the spine's curvature. The alignment of individual vertebrae is critical to improve the spine's curvature. The 360-degree groove allows for the right amount of pressure on each vertebrae's outside edges. Each joint will stretch gently and you may hear your back pop as the vertebrae align.
Each foam roller features a groove design so the spinous can float. They also have supporting edges for the vertebrae's transverse process portion. You should lie over the Neck or Back Shaper roll to allow your tight muscles to relax and your vertebrae to shift into a more optimal location.
Try lying over both the Neck and Back Shaper rolls in order to passively encourage ideal curvature.
Check out the Neck and Back Shaper Sizing Kit to figure out where to start. And click here to learn how to perform the Back-Twist.