I have back problems as well. I've been to doctors, chiropractors, and massage therapists and everyone has a different theory about what is wrong with my lower back. The consensus seems to be that I had some type of traumatic injury (likely an impact, probably during my earlier days as a martial artist). It presents as something not unlike what happens to people in car accidents. I'm usually OK in everyday life, but long walks or vigorous exercise can aggravate it to the point of painful spasms and limited mobility.
Working on advanced pole tricks, especially shoulder mounts, aerial inverts, and legs-off tricks like ayesha, was majorly bothering my back. I would experience spasms and limited mobility whenever I had an attack, and having an attack while inverted on the pole was very scary. That's why I'm not poling at the moment.
It's super important to work within your limits and don't compare yourself to others who are working without injuries. That was a big problem for me - I'd want to keep up with everyone else in classes or workshops, and push myself too hard as a result. I really beat myself up over it emotionally.
To get better, I took time off from pole, and I also got more seriously into yoga to build up my core, glutes, back, and hips. It's very important to realize that "core strength" is not the same thing as "abdominal strength" or "back strength." Veena's lessons do go into the differences. In a nutshell, your core is all about stability, whereas your external muscles are about movement. True core exercises are felt very deep and usually don't look like much to a bystander. Yoga helped me so much with developing my core, so I'm doing yoga teacher training this fall so I can deepen my understanding and share the benefits with others.
Good luck and train safe!