@musimary, You peaked my interest with your discussion. While I don't have what I would call real back pain I do have degenerative arthritis in my spinal cord and lower back issues that make it hard for me to walk distances. I was not aware of this but did find a few references while you wait for members with experience to respond.

-- Helping the Body Heal Itself: Injected Stem Cells for Back Pain
https://heal.nih.gov/news/stories/injected-stem-cells-back-pain
-- Evaluating the safety and efficacy of mesenchymal stem cells in the treatment of low back pain
https://www.mayoclinic.org/medical-professionals/physical-medicine-rehabilitation/news/evaluating-the-safety-and-efficacy-of-mesenchymal-stem-cells-in-the-treatment-of-low-back-pain/mac-20543434