I'm had chronic low back pain for a year with no improvement after seeing 3 chiropractors, any suggestions?

See a spine surgeon: Consult with a board certified spine surgeon to get an opinion regarding more specific options such as injections or surgery. It will not go away on its own at this late stage.

See orthopod: Sounds like a typical chiropractic sequence. They offer quick relief with a deep massage. They offer no proper diagnosis and no cure. You have had a problem for over a year with no diagnosis. See an orthopedic specialist and get an answer and stop wasting money and time on treatment which cannot treat.

See Spine Specialist: If after all you are doing you are still in pain, you should consider seeing a fellowship trained spine specialist who would need to evaluate if your care was done correctly and who may be open to the idea of other options such as prolotherapy, stem cell therapies and maybe even targeted/specialised physical therapy. Many times these newer treatments are not covered under insurance so be prepared