full article 2750 words
Are the little bundles of nerves that exit your spine the wellspring of visceral vitality? Will your organs wilt like neglected house plants if your nerve roots are slightly impinged? This is what many chiropractors would like their customers to believe — while others speak out against it. In journals, even.1
The subluxation theory of chiropractic is a pre-scientific idea with a strong streak of vitalism. It was born and promoted over a century ago well before the relevant anatomy and physiology was known, before the foundations of modern neurology were built.
The idea that spinal manipulation is good for the spine itself — for neck pain and back pain — is a completely different concept and a whole ‘nother discussion: see Does Spinal Manipulation Work?. For an overview of chiropractic beliefs, practices, and controversies, see Does Chiropractic Work? This article is only about the spine-organ relationship.
There are many ways of arguing that organ health is not dependent on spinal function. For instance, victims of serious spinal injuries are not afflicted with organ failure. And nerve roots are actually quite difficult to “pinch” to any meaningful degree in the first place. And so on.
But the main point of this article is that…
It’s not just that visceral tissues don’t benefit much from the life-giving sauce of spinal nerve root signals — they don’t depend on them at all. Only musculoskeletal structures do. Bones, muscles, and skin are completely at the mercy of the big bundles of nerves that pass between vertebrae. Pinch them hard enough and there’s trouble for sure… but not with an organ. Cut a nerve root completely, and you’ll certainly paralyze something … but not an organ.
Spinal nerve roots do not directly “hook up” to organs with a single direct and exclusive connection. Those connections are somewhat indirect and highly redundant — much like the blood supply to most tissues — and the neural supply the organs do get is weirdly unimportant, kind of like your tonsils.2 In fact, organs can be transplanted without hooking them up to any nerves at all!
The body’s organs are innervated primarily by autonomic nerve ganglia and plexuses located outside the spinal column, supplied largely by autonomic cranial and sacral nerves that pass through solid bony openings and by preganglionic spinal cord fibers. The very important vagus nerves traverse openings in the base of the skull and travel down to supply thoracic and abdominal organs. Overlapping autonomic nerve supply from many directions and sources, along with chemical, hormonal, and circulatory factors, assures function of the body’s organs, unaffected by a segmental dysfunction (subluxation) and independent of spinal nerves that are designed primarily to supply musculoskeletal structures.
Spines & their nerves are remarkably unimportant in terms of keeping a sack of organs running smoothly.Organs pretty much run themselves, with just a little bit of optional signalling from mostly non-spinal nerves. Our general health is also regulated (in a big way) by hormone signalling through the fluids of the body, which is also entirely independent of spinal nerve function.
Spines and their nerves are remarkably unimportant in terms of keeping a sack of organs running smoothly.
This is unambiguous biology and anatomy fact, but of course that doesn’t stop some chiropractors from contradicting it. I have received many angry e-mails about this point. I will now turn to those objections … and spend more time with them than with the original point, which is really quite straightforward.
One half-right rebuttal is that incontinence is a well-known symptom of serious spinal nerve root injuries. The bladder is an organ and it can fail with spinal nerve root injury, ergo spinal nerves hook up to organs, ergo chiropractic spinal adjustment can affect organs and general health, ergo this article is wrong.
Actually, I’m not sure that rebuttal is even half right. Maybe one third? One quarter? Let’s clear this up.
The part that’s right: Urinary and fecal incontinence are indeed symptoms of trauma to the lower end of the spine. In this one limited sense, which has pretty much nothing to do with chiropractic adjustments, spinal nerve roots do indeed “hook up” to the bladder and lower bowel. When those nerves are damaged it’s called cauda equina syndrome, and you really don’t want it to happen to you.
So that part’s right. But from that one bit of rightness came a whole bunch of wrong.
The sphincter factor: However, the spinal nerve roots that do this are not causing “organ failure” but “sphincter failure” — failure of the ring-shaped muscles that keep people from leaking.4
The sacral fortress: Furthermore, the nerve roots involved are too low to be affected by any kind of “spinal adjustment.” They emerge from a row of holes in the sacrum, the large wedge of bone between your butt cheeks. The spinal nerve roots that do this are not causing “organ failure” but “sphincter failure” — failure of the ring-shaped muscles that keep people from leaking.5
Third-class organs: Let’s face it, the bladder and lower bowel barely qualify as organs anyway. I wouldn’t want to live without them, but they are not in the same league as a liver or a kidney. They aren’t “vital” organs. So even if spinal nerve roots were actually critical to bladder health, and even if they could be helped by spinal adjustment, it would hardly be a big win for chiropractic.6 Your health is not determined by your bladder!
And your bladder health is not determined by your spine.
Another common rebuttal to this article is that irritated spinal joints “send” their dysfunction to neighbouring structures. This is much like the well-documented phenomenon of “referred pain” — pain felt at a location other than the source, such as shoulder and arm pain caused by a heart attack. But pain isn’t the only thing that can be referred. For instance, we know that spinal joint pain can affect sympathetic nervous system functions in the structures that the nerve supplies.
But not other structures, as far as anyone knows. Just the tissues the spinal nerves actually connect to directly. Not organs. Or the nerve ganglia that supply them. There is no significant referral effect that might cause organ failure or even suboptimal performance.7
This rebuttal is also not quite relevant to the physiology of impinged spinal nerves, but the physiology of any irritated spinal joint — with or without a nerve pinch — and so it is only tangentially related to the main claim that organ health is compromised by spinal nerve impingement.8 And so the referral rebuttal actually has nothing to do directly with “pinched nerves.” Even if the pinch was real, and even if it could be relieved, it’s hardly a guarantee that the joint itself would not still be seriously cranky.
The referral rebuttal is an explanation in search of a phenomenon. Frank visceral disease simply does not correlate at all with spinal injury and dysfunction, and there is extensive evidence of absence of any therapeutic effect derived from such a relationship.9
There is an indirect neurological connection between spinal nerves and some organs, and some readers have called foul on me for not acknowledging it. So I will now acknowledge it… and explain why it doesn’t really matter.
Yes, there is indeed a type of nerve (sympathetic) that comes out of the spine through the nerve roots (ventral horn), and they do “sort of” affect organs. However, it’s not a direct connection or a strong effect.
After leaving the spine, these nerves do not go very far: they deliver one kind of regulatory signal to nerve bundles (ganglia) just outside the spine, and that’s the end of the line for them. The ganglia are like wee tiny little brains, free to make “decisions” to pass those signals on to organs … or not. It’s like getting off at a giant airport and maybe getting on another plane. Maybe.
This isn’t just an academic distinction. The transfer of those signals from spine to organ is not inevitable. It really is a “maybe,” determined by a number of other factors. It is a “connection,” but it’s a very different sort of connection.
There is nothing vital to the vital organs in those nerve fibers. They deliver their signals to complex junctions that continue to do their thing just fine with or without input from the CNS. Even if the flow of information from the CNS is completely interrupted, the ganglia (and the organs) still get most of the information they need from other sources. Because the ganglia are vertically connected by fibres mainly outside the spinal column, sympathetic signals are even routed past nerve root lesions to some extent. Cutting the spinal cord completely destroys motor and sensory function below that level, but organs carry on without any trouble, for decades, and quadriplegics do not die of organ failure.10
As mentioned above, organs mostly run themselves. Their health and function is just not dependent on those signals. This why, in a very general sense, organ transplantation is an option: organs need a blood supply to survive in a new body, but they do just fine without hooking up any nerves … and lucky for us, because we don’t have the technology for that.
So this is the difference: motor and sensory neurons span the full distance from tissue to spinal cord — a continuous anatomical connection that is unambiguously critical to muscular action and sensation. The sympathetic nerves have an indirect and definitely non-critical functional connection to organs.
In early versions of this article I felt it was a complex but ultimately irrelevant tangent, that might make my point seem weaker without actually being weaker. However, I got too many irritating complaints from chiropractors who believed I was ignorant of the biology that I decided to publicly explain: not only am I aware of the biology, I am aware that it doesn’t actually support their point, and doesn’t matter in the end. Which is a good point to end on…
Every twist and turn in the argument is ultimately irrelevant. The absence of organ failure in victims of spinal lesions proves in one logical stroke that organs cannot be dependent on the integrity of the spinal cord. I’ll give the last word to someone with far more expertise than myself:
Another source of evidence that the chiropractic theory of subluxations and innate intelligence is completely false comes from the unfortunate victims of spinal trauma. There are many victims of complete transection, or disruption, of the cervical spinal cord in the neck. Such a complete injury leaves its victim quadraplegic, unable to move the arms or legs. If the injury is high enough in the spinal cord the victim may not even be able to breath on their own. In such victims no impulses from the brain are able to travel below the spinal cord in the neck, and therefore most of the communication between the brain and the body is interrupted. Certainly, this is a much more dramatic and complete interference of nerve flow than that of an impinged spinal nerve.
Yet, in these patients, the organs continue to work without difficulty and diseases do not develop at any higher rate than those without such an injury. Of course, there are some effects from the disruption of the autonomic nervous system, that part of the nervous system which regulates the bladder, the degree of bowel motility, and other functions. But all effects of spinal cord damage are caused by known neurological injury. If subluxation theory were correct, then patients with high spinal cord injuries would be ravaged by every conceivable disease.
I am a science writer, former massage therapist, and I was the assistant editor at ScienceBasedMedicine.org for several years. I have had my share of injuries and pain challenges as a runner and ultimate player. My wife and I live in downtown Vancouver, Canada. See my full bio and qualifications, or my blog, Writerly. You might run into me on Facebook or Twitter.
This landmark paper penned by four chiropractors is a strong indictment of a philosophical pillar of their own profession. Although a bit of a moving target over the years, subluxation theory generally refers to idea that spinal joint dysfunctions have broad health significance, which has been a major component of chiropractic thought since the founding of the profession. The authors analyze and condemn it:
No supportive evidence is found for the chiropractic subluxation being associated with any disease process or of creating suboptimal health conditions requiring intervention. Regardless of popular appeal this leaves the subluxation construct in the realm of unsupported speculation.
And yet it’s been there for more than a century, I’d like to add.BACK TO TEXT