X-Ray Misconceptions

An excerpt written by: Dr. Burl Pettibon from his chapter “X-Ray Procedures”

The Pettibon System has the goal to correct abnormal spinal form and function. The Pettibon System’s scientifically verifiable method of X-ray Procedures enables practitioners to detect and precisely measure abnormal spinal form and function.

Following The Pettibon System X-ray Procedures, radiographs are taken in mutually perpendicular planes through a single bone to establish an origin for measurement.

In the absence of an established origin, the corrections some chiropractors claim to have measured on x-rays can be challenged as being the result of faulty positioning or repositioning of the patient. For example, the normal curvatures of the spine can be made to appear as if scoliosis is present in the A–P x-ray solely by faulty positioning. Criticisms of this nature are not possible with The Pettibon System X-ray Procedures because, in addition to an established origin for measurement, precise positioning techniques and aligned x-ray equipment are used.

The inability of conventional chiropractic x-rays to detect displacements has put more emphasis on their purpose being the exposure of fractures and pathology so, if present, appropriate referrals can be made.


Through the years, various misconceptions have been taught and adopted by chiropractors as the truth. For example, consider the following:

  1. Spinal displacements are not visible on x-rays; therefore, they cannot be measured. This statement is inconsistent with published research in the Journal of Manipulative Physiological Therapeutics,³ which established the reliability of The Pettibon System X-ray Procedures.

The AMA Guides to the Evaluation of Permanent Impairment1,2 uses x-ray and measurement of spinal displacements to determine alterations of motion segment integrity and percentage of permanent partial disability (PPD) to be awarded.

The following information is found in the AMA Guides to the Evaluation of Permanent Impairment: 1,2

Loss of Motion Segment Integrity. “Motion Segment Alteration” causes abnormal function.

Motion Segment: Defined as two adjacent vertebrae, the intervertebral disk, the apophyseal or facet joints, and the ligamentous structure between the vertebrae.

Alteration of motion segment integrity can be either loss of qualitative motion, increased translation or angular motion, or decreased quantitative motion.

“Motion of the individual spine segments cannot be determined by a physical examination but is evaluated by flexion and extension roentgenograms.”

“Transitional loss of motion segment integrity defined: An anterior-posterior motion of one vertebra over another, greater than 3.5mm in the cervical spine, greater than 2.5mm in the thoracic spine, and greater than 4.5mm in the lumbar spine.”

The preceding explanation of soft tissue injury and impairment ratings from the AMA Guides are necessary for “a reasonable degree of certainty of diagnosis before beginning treatment.”

X-Ray Positioning Myth

  • Patient positioning is non-repeatable, so the same x-ray cannot be repeated (take with the patient in exactly the same position for post-treatment outcome assessments). This is invalidated by published research titled“Reliability of the Pettibon Patient Positioning System for Radiographic Production,” printed in the Journal of Vertebral Subluxation Research, 2000.3
  • It does not matter that spinal displacements or patient position for x-rays cannot be seen or reproduced on x-ray because spinal displacements cannot be corrected anyway. This is invalidated by published research titled, “Improvement of Cervical Lordosis and Reduction of Forward Head Posture With Anterior Head Weighting and Proprioceptive Balancing,” printed in the Journal of Vertebral Subluxation Research, 2003.4
  • The position of the skull (bite line) differences on pre-and post-treatment x-rays do not influence cervical lordotic measurements on lateral cervical x-rays. This is invalidated by published research, “The Effects of Bite Line Deviation On Lateral Cervical Radiographs When Upper Cervical Joint Dysfunction Exists: A Pilot Study,” in the Journal of Manipulative Physiological Therapeutics, 2003,5 concluding that a 20.3% measurement difference may result when the bite line is not the same in pre-and post-treatment x-rays.



The Exposure Myth

Humans live in an atmosphere of x-ray spectral energy produced by the sun. Human immune function is actually aided by x-ray spectral energy. However, because newspaper articles and magazines have warned the public about the use of x-ray as the cause of health problems, some patients will actually refuse x-rays based on their belief that exposure is more harmful than the spinal problem. The Mayo Clinic has established guidelines for radiation exposure that allow a patient to make an informed decision regarding the Pettibon System X-ray Series. A Mayo Clinic Newsletter from February of 1990 states that radiation exposure of a fetus should not exceed 10,000mR. To understand what this means, and how much 10,000mR really is in terms of exposure, note the following: Annual radiation from our environment = 300mR.12 chest x-rays = 300mR.The Pettibon X-ray Series (7 views) = 20mR.To exceed 10,000mR per year, one would have to take more than 3,395 Pettibon-type x-rays of the patient. The design of x-ray equipment and filters has removed the fear of radiation-induced disease, although some practitioners still use this excuse for not taking pre-and-post-x-rays.




  1. American Medical Association. Guides to the Evaluation of Permanent Impairment,4th ed. 1995 Chicago, IL
  2. American Medical Association: Guides to the Evaluation of Permanent Impairment, 5th ed. 2000 Chicago, IL
  3. Jackson BL, Barker WF, Pettibon BR, Woggon D, Bentz J, Hamilton D, Weigand M, Hester D: Reliability of the Pettibon patient positioning system for radiographic production. J Vertebral Subluxation Research 2000; 4(1):1-9
  4. Saunders ES, Woggon D, Cohen C, Robinson DH: Improvement of cervical lordosis and reduction of forward head posture with anterior head weighting and proprioceptive balancing protocols. J Vertebral Subluxation Research 2003; 4:E1–5
  5. Stitzel CJ, Morningstar MW, Paone PR: The effects of bite line deviation on lateral cervical radiographs when upper cervical joint dysfunction exists: A pilot study. J Manipulative and Physiological Therapeutics 2003; 26(7):e17