Aim: To find out what midline back pain means. Method: Analysis of variance on database of 88 clinical variables collected prospectively from 1655 consultations for chronic low back pain patients.Results: This study showed that drawing a central site for back pain and saying that a back problem is midline often seem to be different things. It also seemed that it was more important to check whether 'central or bilaterally equal' back pain was induced by sagittal plane tests such as standing flexion or extension, or supine sit-ups or back arching. A subsection of this concept was provoked by lateralized testing with left or right lumbar rotation or lateral flexion causing central pain. There was also a hint that midlineness was at the milder end, and bilateral equalness was at the other more severe end of a symmetrical severity of pain spectrum. Conclusion: The original Schwarzer et al. 's (1994) premise that facet joint pain is never central was supported. But it seemed that there were better tests that positively identified the facet joint syndrome, and that a patients drawing or statement description of central back pain would not be a reliable indicator of midline degenerative disc disease. The latter might be better defined by sagittal plane tests provoking symmetrical back pain.