Yes, they combine various yoga poses to create a complete workout for your back (= they make every muscle that sustains your spine work)

I think that it's not so important to do every rite perfectly, but rather to start somewhere and do what you can adjusting it to your abilities. At least I focus on improving and if one day I'll become as flexible as the lady in the video, even better

Let me know if you try, I'm very interested in other people's experience. After years of pain it's such a relief to finally find something that helps and I'm very eager to share it so that others can benefit from it as well