Some of the most common conditions which cause back pain include arthritis and DDD (degenerative disc disease). If you suffer from chronic debilitating back pain then it is likely there are resulting physical limitations from your condition. Although this point seems obvious, the SSA will be looking at the medical record first and foremost for "objective" findings (X-Rays, MRIs). Next, do the progress notes document in some way that there are physical limitations (inability to stand/sit for certain period of time, inability to crouch, bend, stoop, kneel and frequently lift/carry 10lbs or more). Consistent progress notes from a treating physician over a period of time lend credibility and would likely include patient comments/reports of pain (perhaps in addition to numbness/radiating pain from pinched nerves); prescriptions of strong painkillers (norco, oxycontin, etc) are yet another factor lending credibility to the overall picture and especially if more than one physician and/or specialists have consistent reports. Finally, is the claimant's appearance consistent with the medical record  - if there are inconsistencies with the medical record and anything that the Judge sees in person then that may influence the question of credibility.