Back pain is often caused by having a weak core, in which case yoga and planking can make a huge difference.
My Dad, who had chronic back pain, swore by holding on to the side of the pool with light weights on his ankles. YMMV. I agree about core strength.
This machine works wonders: https://allcore360.com. If you can find a therapist who has one near you. They’re pretty rare, but catching on.