Episode 7: What is an Adjustment?

In today's episode, we will discuss the scientific parameters of what can be considered an adjustment.  An adjustment isn't just anything we want to do to create a cavitation, but it has a very specific definition.  We will discuss that definition as well as what is required of us to meet that definition.    • White AA, Panjabi MM. Clinical Biomechanics of the Spine. 2nd ed. Lippincott; 1990. • Adams MA, Hutton WC. The effect of posture on the role of the apophysial joints in resisting intervertebral compressive forces. J Bone Joint Surg Br. 1980. • Hilibrand AS, et al. Radiculopathy and myelopathy at segments adjacent to the site of a previous anterior cervical arthrodesis. J Bone Joint Surg Am. 1999. • Denis F. The three column spine and its significance in the classification of acute thoracolumbar spinal injuries. Spine. 1983. • Wiltse LL, Newman PH, Macnab I. Classification of spondylolysis and spondylolisthesis. Clin Orthop Relat Res. 1976. • Kirkaldy-Willis WH, et al. Pathology and pathogenesis of lumbar spondylosis and stenosis. Spine. 1978. • Herbst RW. Gonstead Chiropractic Science & Art. Sci-Chi Publications; 1968. • Panjabi MM. The stabilizing system of the spine. Part I: Function, dysfunction, adaptation, and enhancement. Part II: Neutral zone and instability hypothesis. J Spinal Disord. 1992;5(4). • Sandoz R. Some physical mechanisms and effects of spinal adjustments. Ann Swiss Chiropr Assoc. 1976;6. • Ross JK, Bereznick DE, McGill SM. Determining cavitation location during lumbar and thoracic spinal manipulation. Spine. 2004;29(13):1452–7. • Herzog W, ed. Clinical Biomechanics of Spinal Manipulation. Churchill Livingstone; 2000. (Preload and thrust force profiles.) • Stephenson RW. Chiropractic Text Book. 1927. (Source for the "body does the adjusting" tradition — confirm the exact passage before quoting.)

In today's episode, we will look at what a subluxation is not.  From this understanding, we can then investigate how the application of a non-subluxation based approach has led to the accusation that Chiropractic is unscientific.  The claim on science is not as simple as some would want to believe. References: • Herbst RW. Gonstead Chiropractic Science & Art. Sci-Chi Publications; 1968. • Association of Chiropractic Colleges. Position paper on the chiropractic paradigm. 1996. • Kirkaldy-Willis WH, et al. Pathology and pathogenesis of lumbar spondylosis and stenosis. Spine. 1978. • Adams MA, Hutton WC. The effect of posture on the role of the apophysial joints in resisting intervertebral compressive forces. J Bone Joint Surg Br. 1980. • Bogduk N, et al. The innervation of the lumbar spine. Spine. 1981. • Olmarker K, Rydevik B, Nordborg C. Autologous nucleus pulposus induces neurophysiologic and histologic changes in porcine cauda equina nerve roots. Spine. 1993. • Hasegawa T, et al. Lumbar foraminal stenosis: critical heights of the intervertebral discs and foramina. J Bone Joint Surg Am. 1995. • Freemont AJ, et al. Nerve ingrowth into diseased intervertebral disc in chronic back pain. The Lancet. 1997. • Donelson R, et al. A prospective study of centralization of lumbar and referred pain. Spine. 1997. • Seffinger MA, et al. Reliability of spinal palpation for diagnosis of back and neck pain: a systematic review. Spine. 2004. • Stochkendahl MJ, et al. Manual examination of the spine: a systematic critical literature review of reproducibility. J Manipulative Physiol Ther. 2006. • National Board of Chiropractic Examiners. Practice Analysis of Chiropractic. 2015 (2014 survey data), as reported by Northwestern Health Sciences University. Check the 2025 edition for newer figures. • Survey of Ontario chiropractors: Frequency of use of diagnostic and manual therapeutic procedures. • Ross JK, Bereznick DE, McGill SM. Determining cavitation location during lumbar and thoracic spinal manipulation: is spinal manipulation accurate and specific? Spine. 2004;29(13):1452–7. • Flynn TW, et al. The audible pop from high-velocity thrust manipulation and outcome in individuals with low back pain. Arch Phys Med Rehabil. 2006. • Farfan HF, et al. The effects of torsion on the lumbar intervertebral joints: the role of torsion in the production of disc degeneration. J Bone Joint Surg Am. 1970. • Adams MA, Hutton WC. Prolapsed intervertebral disc: a hyperflexion injury. Spine. 1982. • Chiradejnant A, et al. Efficacy of "therapist-selected" versus "randomly selected" mobilisation techniques for the treatment of low back pain. Aust J Physiother. 2003. • de Oliveira RF, et al. Immediate effects of region-specific and non-region-specific spinal manipulative therapy in patients with chronic low back pain. Phys Ther. 2013.

Chiropractors have defined "subluxation" hundreds of ways.  The Gonstead Clinical Studies Society has held one definition for more than fifty years; a physical lesion at the disc, not the facet. Dr David Fowler traces how Clarence Gonstead built his model the way an engineer would, starting with the anatomy, and shows why decades of biomechanics research still fit it. Then he turns to the profession's harder problem: title-holders who dismiss a testable model while practicing without one. Titles open doors, but they don't close arguments. That standard applies to everyone, Fellows included.  References: • Herbst RW. Gonstead Chiropractic Science & Art. Sci-Chi Publications; 1968. • Rome PL. Usage of chiropractic terminology in the literature: 296 ways to say "subluxation." Chiropractic Technique. 1996. • Association of Chiropractic Colleges. Position paper on the chiropractic paradigm. 1996. • World Health Organization. WHO Guidelines on Basic Training and Safety in Chiropractic. 2005. • Mootz RD. Theoretical models of chiropractic subluxation. In: Gatterman MI, ed. Foundations of Chiropractic: Subluxation. 1995. • Mirtz TA, et al. An epidemiological examination of the subluxation construct using Hill's criteria of causation. Chiropractic & Osteopathy. 2009. • Nachemson A. Intradiscal pressure studies, 1960s. • Kirkaldy-Willis WH, et al. Pathology and pathogenesis of lumbar spondylosis and stenosis. Spine. 1978. • Adams MA, Hutton WC. The effect of posture on the role of the apophysial joints in resisting intervertebral compressive forces. J Bone Joint Surg Br. 1980. • Bogduk N, et al. The innervation of the lumbar spine. Spine. 1981. • Freemont AJ, et al. Nerve ingrowth into diseased intervertebral disc in chronic back pain. The Lancet. 1997. • Donelson R, et al. A prospective study of centralization of lumbar and referred pain. Spine. 1997. • Seffinger MA, et al. Reliability of spinal palpation for diagnosis of back and neck pain: a systematic review of the literature. Spine. 2004. • Stochkendahl MJ, et al. Manual examination of the spine: a systematic critical literature review of reproducibility. J Manipulative Physiol Ther. 2006. • Sackett DL, et al. Evidence based medicine: what it is and what it isn't. BMJ. 1996.

In today's episode, we will discuss the word specificity and what do we actually mean when we say it.  More to the point, we will discuss how we can adjust with greater specificity by incorporating the known physics and the relevant research.    Newton / Euler — force through the center of mass produces translation; offset force produces translation plus rotation (τ = Iα). Free-body idealization. White & Panjabi, Clinical Biomechanics of the Spine — instantaneous axis of rotation (IAR) and coupled motion in spinal segments; the constrained-body reality behind the center-of-mass teaching model. Kirkaldy-Willis & Farfan — the degenerative cascade; disc as primary lesion; the pathomechanical target the correction vector is aimed at. Herbst, Gonstead Chiropractic Science and Art — the listing as a directional/rotational statement referenced to the disc; Gonstead's emphasis on line of drive and torque as evidence the tradition is, at its best, already a vector system. Popper — falsifiability as the demarcation of a scientific claim; a definition that cannot be wrong isn't worth having. Shackel — the motte-and-bailey maneuver; the retreat from the movement claim (bailey) to the intention/contact claim (motte). Boundary conditions (basic engineering mechanics) — the fixed vs. free beam: identical force, different constraint, different result. Analogy for stabilization defining the caudal boundary that makes an axis (and therefore a vector) exist. Herbst, Gonstead Chiropractic Science and Art — stabilization of the segment immediately beneath the target; the doctor's body used to limit motion rather than generate it (contrast with motion-generating side-posture setups). Panjabi — the neutral zone and the passive/active/neural stabilizing system; instability as enlargement of the neutral zone. Basis for "the caudal segment may itself be lax." Kirkaldy-Willis — the instability phase of the cascade as the setting where an undefined foundation is most dangerous; the sicker the disc, the more the wall matters. (Set aside, not relitigated this episode) — the cavitation-location / inter-examiner reliability literature (e.g., Ross, Bereznick & McGill). That's the downstream "can we reliably do it" fight; today is strictly the upstream "what does it mean" question.

In today's episode, we will look at the accountability vacuum and how this plays out when it comes to patient outcomes.  We will look at some guiding philosophies that help us to see how it isn't the worst among us who become corrupted, but it is often the very best.  

In this episode, we will be looking at what happens to young chiropractors when they graduate.  This is an important question, but one that we have very little evidence to inform us.  The future of the profession depends heavily on the answer to this seldom asked question. 

This is our foundational episode.  Who we are and the rules of the game that govern how we analyze the philosophy, art, and science of Chiropractic through a Gonstead lens.