In Pilates, full movement through all the vertebrae elongates and articulates the spine to increase the range of motion and strengthen the stabilizing muscles both in your back and in your core. You will hear your instructor say during your class or in your private session, "One vertebrae at a time," when you are rolling up, rolling down, standing, sitting or lying on either the mat or the reformer. What this means is in your movement, you are putting one vertebrae on top of the other starting from the coccyx up through the spine right to the head. Here is a really good exercise to show you by using a wall.
(Wearing sneakers is best for stability!)
1. Start by standing with your back up against a wall. If your back is not flat, no worries - don't force it. The next move will help flatten & stabilize it.
2. Walk your feet out slowly to get your back flat on the wall, with your knees slightly bent, heels together, toes a little apart. Ahh, it feels really good.
3. So now, chin to chest, slowly start to roll down one vertebrae at a time and bring your arms with you so they are by your sides, relaxed. Stop when you are at your waist - you want to keep your sacrum on the wall.
4. Start to roll up on the wall one vertebrae at a time, gently pressing your back from the abdomen, to the wall, till you reach the top.
5. Slowly walk your feet in, place the palms of your hands on the wall, and gently walk away. You should already feel taller.