There is a common misconception in the chiropractic community that measuring osseous displacement on X-ray is unreliable, and radiographs should only be taken to assess pathology.
However, a 1998 study published in the Journal of Manipulative and Physiological Therapeutics showed that interclass correlation coefficients (ICC) for locating pathology on X-ray was only 0.4–0.75, while line drawings for X-ray displacement had ICC's in the 0.8–0.9 range.
Many chiropractic schools also suggest digital palpation is all you need to determine where a patient needs to be adjusted. Despite these teachings, static and motion palpation repeatedly shows below average to poor intra-examiner reliability in the published research. Trained Advanced Orthogonal doctors utilize clinical procedures that promote the highest degree of intra and inter examiner reliability.