They Were Right About Specificity. They Were Wrong About the Bone.
- Dr. Lucas Marchand
- 5 days ago
- 6 min read
What Clarence Gonstead understood intuitively—and what his followers got almost right
Lucas Marchand, DC - MyChiro - Sioux Falls, SD 4/18/26
There is a moment, early in chiropractic school, when the Gonstead technique is presented with the reverence usually reserved for scripture. The Cervical Chair. The Knee-Chest table. The full-spine X-ray analysis. The level disc theory. And above all else, the central doctrine: find the bone that is out of place, contact it precisely, and move only that bone.
I spent years taking that doctrine seriously. I still do—but not in the way I was taught to.
Clarence Gonstead, a Wisconsin-based chiropractor who built one of the busiest practices in the country during the mid-twentieth century, was onto something real. The problem is that his followers preserved the conclusion while discarding the reasoning—and in doing so, they calcified a useful instinct into an anatomical mythology that doesn't hold up.
The instinct was correct: specificity matters in spinal manipulation. What they got wrong was where that specificity actually lives.
The Mythology of the Isolated Bone
To understand what Gonstead was after, you have to understand the environment in which he was practicing. Mid-century chiropractic was, by many accounts, a profession that adjusted everything, everywhere, all the time—and called it a science. Gonstead pushed back. He wanted precision. He wanted a method that could be taught, replicated, and defended.
The system he built was organized around a compelling premise: that spinal dysfunction originates at a specific vertebral level, that this level can be identified through X-ray, static palpation, and instrumentation, and that the adjustment should contact only that segment—moving it back toward its correct position while leaving adjacent vertebrae undisturbed.
The clinical outcomes Gonstead produced were apparently remarkable. His clinic in Mount Horeb drew patients from across the country. That part of the story is plausible.
The biomechanical premise, however, is not. The spine does not move segment by segment. The facet joints at each level are continuous with the ones above and below. Paraspinal musculature crosses multiple levels. Ligamentous tension distributes load across the motion segment and beyond. When a manipulative force is introduced at L4, the idea that L3 and L5 are passive bystanders is a fiction—a clean story that the actual tissue does not cooperate with.
This is not a criticism of Gonstead's outcomes. It is a criticism of the explanation built around them.
Diversified and the Other Extreme
If Gonstead represents one pole of the specificity debate, Diversified technique represents the other. Diversified is less a system than a collection of approaches—a toolkit assembled from multiple traditions, with the practitioner making real-time decisions about contact points, positioning, and thrust direction.
The critique of Diversified, often made by Gonstead purists, is that it lacks rigor. That without a systematic diagnostic framework—without the full-spine films and the precise listing nomenclature—you are essentially guessing. Applying force to a general region and hoping for the best.
There is something to this critique. I have seen chiropractors practice Diversified in a way that amounts to a bilateral lumbar roll on everyone who walks through the door, regardless of presentation. We all know "The Flying Seven Technique." That is not specificity—it is a habit dressed up as a technique.
But the solution is not to retreat into Gonstead mythology. The solution is to ask more carefully what specificity actually means.
The Vector Is the Specificity
Here is what I have come to understand after a decade of mobile practice, treating patients in homes, workplaces, and a fully equipped van that has logged more miles than I care to count: the bone was never the point.
Specificity in spinal manipulation lives in the vector. Not just the primary plane—posterior-to-anterior, anterior-to-posterior—but the full three-dimensional direction of force delivery. The superoinferior component. The angle of the thrust relative to the joint plane. The velocity and amplitude at which that force is introduced.
Consider two lumbar adjustments that look identical from the outside. Same contact point. Same patient positioning. Same audible release. In the first, the thrust is directed posterior-to-anterior with a cephalad component—loading the inferior joint surface, gapping the superior facet. In the second, the same contact is used with a caudal component—an entirely different set of structures is being tensioned, an entirely different segment of the facet capsule is under load.
These are not the same manipulation. Listing them identically in a SOAP note does not make them the same manipulation. And calling one of them a "specific" Gonstead adjustment while calling the other a loose Diversified thrust misses the actual variable entirely.
What matters is whether the practitioner knows—consciously, deliberately—what the force direction is doing at the tissue level. That is the specificity Gonstead was reaching for. He just located it in the wrong anatomical variable.
The Neurological Argument for Precision
The case for vector specificity is not only mechanical—it is neurological. The paraspinal mechanoreceptors that respond to manipulation are velocity-sensitive. Golgi tendon organs, Ruffini endings, Pacinian corpuscles: these structures detect the rate of change in tissue deformation, not just the magnitude. The neurological effect of an adjustment is therefore not simply a product of how much force is applied, but of how that force is directed and how quickly it is introduced.
A sloppy, high-amplitude thrust delivered in an indeterminate direction produces stimulation—but not necessarily useful stimulation. It activates mechanoreceptors, likely generates cavitation, probably feels like something to the patient. But without intentional vector control, you are essentially broadcasting on all frequencies and hoping the right signal gets through.
Deliberate vector control—knowing whether you are loading the joint in a distraction-dominant or shear-dominant direction, and choosing that based on what the segment actually needs—narrows the broadcast. It is not that adjacent segments stop being affected. They are always affected. But the primary mechanical event becomes more predictable, and the neurological input more targeted.
What to Keep from Gonstead
I do not think the answer is to discard Gonstead and declare Diversified the winner of a debate that was never framed correctly. The question was never which technique is right. The question is what each tradition understood about the adjustment that the other missed.
From Gonstead, I keep the commitment to precision. The insistence that sloppy technique is not a style choice but a clinical failure. The recognition that contact point, patient positioning, and line of drive are not interchangeable variables. The understanding that an adjustment is not merely a mechanical event but a deliberate intervention that should be chosen for a reason.
What I discard is the mythology of the isolated segment. The vertebra is not a discrete unit of dysfunction. It is embedded in a system, and any intervention introduced into that system distributes across it. Accepting this is not a concession to imprecision—it is a more honest account of what the tissue is actually doing.
From Diversified, I keep the flexibility. The willingness to adjust positioning based on presentation rather than protocol. The recognition that a good clinician adapts, that the same listing does not always call for the same approach, and that technique should serve the patient rather than the system.
What I discard from Diversified is the comfortable vagueness—the bilateral lumbar roll that is not really a decision, the thrust that could mean anything because the practitioner hasn't committed to it meaning something specific.
The Practical Question
The practical question that follows from all of this is simple, and it is one I ask myself before every adjustment: do I know what this force is doing?
Not whether I have identified the correct vertebral level—a question I hold with considerably more uncertainty than I was trained to. But whether I know the direction of my thrust, the angle relative to the joint plane, the cephalad or caudad component, the velocity and amplitude I am choosing and why.
If I cannot answer that question, I am not adjusting—I am guessing with my hands. And no amount of Nervoscope readings or full-spine radiographs will rescue a guess dressed in the language of precision.
Gonstead built a myth. But the instinct underneath it—that specificity is what separates adjustment from impulse—was right. It just needed a better address.
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