My guess is you'll have to establish documentation and history on your condition. Diagnostic tests, MRIs, Scans along with Doctors' interpretations on these tests as well as their observations on your condition and ability to function will help verify your condition. Obviously being on Disability and some sort of pain management protocal for an extended period of time would probably be beneficial to validating your claim. Be aware that some tests to locate and diagnose spinal problems, such as a Discogram can be extremely painful.

I'm not sure what the criteria is going to be in terms of proving that one has chronic pain, but I would start with your GP and get referrals to see specialists in the Orthopedic, Surgical and Pain Management fields, and start building a medical file.

It's quite possible that the above will not be necessary, dependent on the recommendation of some of Doctors at these clinics that are opening up specifically to help applicants obtain MMJ cards. Judging from the comments from DHS there seems to be a commitment to strictly validate claims, and eliminate any type of quackery. We'll know more when April rolls around and they(DHS) starts to accept applications for the cards. I would get to a Doctor right away and have them help with your condition.