This soft but supporting foam roller is flat on one side so it stays in place while you use it. In mat Pilates classes you will really feel your spinal alignment without the bulk of your shoulders and hips to distract you. For Equipment Pilates classes it might go under your hips to help your lower abdomen better handle the wright of your legs and the challenge of the resistance. Lying spine on the roller and wiggling, twisting, and otherwise moving the spine is a great gentle fascial release for a tight spine. 3′ long is plenty of size to match even the longest torso I have seen!
As always, I suggest you try before you buy and that you take a movement class or several before selecting your fascia props for home use.