Last week, a Reddit user asked a sincere question in r/explainlikeimfive:

What actually happens when a chiropractor ‘cracks your back’? What are they doing, what makes the noise, and why do we feel different afterwards?

That’s a reasonable question, whether you’ve been practicing for decades or a patient naive to how chiropractic works. The maelstrom of comments, though, is a clear example of just how uninformed the general public are about the chiropractic profession, adjustments, and the current scientific research showing whether/how it works. In a matter of hours, the thread ballooned to 647 comments before being locked by a moderator.

There were thoughtful and well-written responses from chiropractors and physical therapists with reasonable explanations. There were handfuls of personal and second-hand anecdotes of relief as well as horror stories. And, of course, there were the dogmatic anti-quackery trolls. You can read the entire thread here, but I’ve selected a few (edited) comments to give you a feel for what people really think.

Reasonable explanations

The most well-received answer comes from a PT in a Scandinavian country:

No one knows why you feel better afterwards. The popping noise can be explained by how manual practitioners like chiropractors take out the maximal range of motion of the joint(s). This sudden distraction of the joints causes a cavity to form in the joint fluid (synovial fluid), which makes a popping sound. –u/bahggafagga

They continue in a postscript added later: “Not all chiros are quacks, chiros are a weird profession that differ a lot from country to country, and with [differing] schools of thought.”

A chiropractic student bravely chimed in with a simple, but accurate, description of the phenomenon:

The “crack” you here [sic] is essentially the conversion of liquid to gas when there is a rapid change in pressure in a joint. It’s known as tribonucleation.

The best way I can think to describe why you feel different is to compare it to when you stub your toe or jam your finger. You immediately start to rub or squeeze your toe or finger in an attempt to replace the feeling of pain with the sense that you’re squeezing it or rubbing it. Now apply that to a joint. When a joint isn’t able to move properly it can lead to pain, so an adjustment works on the same principle while at the same time bringing that joint into the range of motion it wasn’t previously able to go through. –u/lawrence4180

It would have been nice if at least one person would have linked to a scientific paper that explains what is happening in the joint during cavitation. Kawchuck, Fryer, et al would have been a good place to start.¹

The Trolls

Of course, no discussion about chiropractic on the internet will go ignored by anti-quackery vigilantes.

Everyone should look in to the origins and founder of Chiropractic “Medicine”. He was an insane quick [sic] who straight up made it up as he went on and tried to conflate Chiropractic with its own religion I order to exempt it from medical oversight.

So either the whole thing is a total scam or he happened to stumble across something real, by mistake, while lying through his teeth. –u/Mel1orp²

To be fair, it’s true that the Palmers and other early chiropractors claimed religious exemptions to avoid penalties for practicing medicine without a license.³ Yet, early writings from D.D. vacillated between calling it a religion and insisting that it wasn’t.⁴ Either way, those chiropractors who claimed religious protections probably didn’t even believe what they were claiming.⁵

Kudos to u/i-d-even-k for the response and awareness of current events:

Or his theory had a crumb of truth and modern chiropractors have dropped 80% of his theory (the bullshit) and kept the useful 20%.

Then there’s the bait-and-switch approach. You think they’re providing some honest insight, then hit you with the criticism.

What they are doing is cracking your joints. So all that is happening is just what happens when a joint gets cracked. It causes bubbles in the joint fluid to make a popping sound.

Um, yeah, that’s it. There’s no science behind it. It’s just mumbo jumbo. –u/The_Thunder_Child

Chiropractic is a lot more than just cracking a back. It’s bullshit about how the spine not being aligned properly is the cause of all disease. It’s about charging you money for something that is bullshit. – u/The_Thunder_Child

The Innocently(?) Uninformed

The ~~great~~ thing about Reddit is that people are welcome to comment without feeling the need for any relevant expertise of their own. Having a neighbor will suffice:

And dangerous!

My neighbor growing up was a neurologist who was full of horror stories about the permanent spinal injuries people had gotten from chiropractors. –u/Rojaddit

Or just a friend (of a friend?):

I have a friend who swears her allergies were cured by chiropractic intervention. Her allergies.

Chiropractic medicine is the Mormonism of medicine. Based on a ghost story and everyone who believes in it is always trying to convert you. –u/cflash015⁶

Commenters also have no qualms answering questions when they appear not to have read anything about chiropractic from the last 50 years or so:

There’s no such thing as evidence based chiropractic; the foundations of chiropractic are based in vitalism and explicitly reject the scientific method. –u/Holociraptor

And of course, the educational qualifications become a point of contention:

Role of chiropractor: absolutely nothing. They have zero training in science. Go to a massage therapist instead. –u/Knave7575

Right, because massage therapists receive heaps more scientific training than chiropractors? Fortunately, u/Just_the_facts_ma_m provided a response, including a list of science classes in the standard chiropractic curriculum.

Honestly, your post is a prime example of the bold and willful ignorance propagated by the young and undereducated hive mind of Reddit.

Utterly wrong

There are no peer reviewed or replicated studies that show any long term benefit of chiropractic, there is no federal accredidation [sic] or license, and they are not doctors or physical therapists. –u/raltoid

No studies? None?

Sure, not a plethora and very few that are methodically rigorous or otherwise great. But none?

No federal accreditation?

I don’t know where u/raltoid lives, but a quick search could have revealed that “the practice of chiropractic is recognized and regulated by law in approximately 40 countries” (WFC.org).

Not doctors or physical therapists?

These quick-draw comments reveal little other than ignorance.

Fortunately, the other thing about Reddit are the abundance of fact checkers, and u/Just_the_facts_ma_m stepped up again.

Couldn’t you have spent 5 minutes studying this topic before broadcasting your ignorance?

Personal anecdotes—both good and bad

Any Redditor worth their salt will remind you of the “not the singular of data” tidbit, but anecdotes can be worth considering, if just for the entertainment. A few people shared their positive experiences with chiropractors.

This happy ending is part of a much longer story from u/fastermouse:

I finally made it back to the chiropractor, still on crutches. He worked on me for less than an hour. When he was done I could stand up straight for the first time in a month. He gave me a series of stretches and made an appointment to come back in a week.

This person grew up around doctors, but only found relief after an adjustment:

I grew up calling them quacks, as they did. When I became bedbound from my injuries, and no doctor was offering me hope, in desperation I went to a chiropractor. He had me back at work in one month. –u/MarvinHeemyerlives

This guy was less delicate with his positive opinion.

Goddamn it most of the comments on here piss me off. In my experience ‘Sudden knifing debilitating pain gotta use a cane for the next three days, go to chiropractor, he crackee backee, me walk out pain free’. Jesus Christ. Will this goddamn world stop making blanket judgements

–u/Nakedinsomniac

But, to be fair, others didn’t have the same success:

Well what happened to me personally was, he herniated 2 discs in my neck and ruined my life. I had to get disc replacement surgery at c5-c6 and c6-c7. –u/Pantani23

Unfortunately, some of the stories probably have merit:

Every chiro I have ever tried is a quack.

They usually are pushing other garbage in the form of homeopathy or along those lines. They also are selling some aqua bed or thingamabob.

They all try to get you sign up for some prepaid “maintenance” plan.

They last one I tried, 15yrs ago, was ultra religious and kept pushing his wacky brand of religion. –u/Mythslayer1

To be fair, a lot can change in fifteen years. It may be time for u/Mythslayer1 to again try to find a chiropractor who isn’t a quack. It’s not that hard.

The failure of a profession

That should be more than enough of a sampling to get an idea of the radically polarized opinions about chiropractic on the wild-wild-internet.

Of course, it’s hard to blame many of these commenters. As a profession, chiropractic has done a pathetic job of informing primary care providers–let alone the public–of what we do and relaying the current evidence supporting our approaches to pain and other conditions.⁷ Combined with the fact that the vocal majority of chiropractors often do hold to old theories and anti-science sentiments.⁸

The frequency of comments about misalignments alone should be enough to make any chiropractor realize that we need to do better to dispel old theories and giving our best explanation of how we think spinal manipulations work.

It really is high-time the profession invests in fast-tracking knowledge transfer interventions.⁹

What do you think?

Are there better ways to answer the question, “How does chiropractic work?”

Do these comments represent public opinion fairly, or is the selection bias slanted towards the extremes of both sides?

Let me know in the comments.

Kawchuk, G. N., Fryer, J., Jaremko, J. L., Zeng, H., Rowe, L., & Thompson, R. (2015). Real-time visualization of joint cavitation. PloS One, 10(4), e0119470. ↩︎
I suppose u/Mel1orp should know everything about chiropractic, since he’s got all the koalafications as a carpenter in Australia. ↩︎
Keating, J. C. (2017). D.D. Palmer’s Religion of Chiropractic, 1–2. ↩︎
Palmer, D.D. (1914). The Chiropractor, 6. See also: Brown, C. G. (2010). Chiropractic and Christianity: the power of pain to adjust cultural alignments. Church History, 79(01), 144–181. ↩︎
Thompson, P. (1975). Chiropractor in medical school sees value in interdependence. Canadian Medical Association Journal, 113(5), 454–458. ↩︎
Ironically, my introduction to chiropractic can be traced back to my mom’s experience getting complete and long-lasting relief from hay fever. Oh, and that I might have been conceived only after receiving chiropractic treatment. Oh, and I used to be a practicing Mormon, and this point is spot on. But that’s a whole series of posts in itself. ↩︎
Greene, B. R., Smith, M., Allareddy, V., & Haas, M. (2006). Referral patterns and attitudes of primary care physicians towards chiropractors. BMC Complementary and Alternative Medicine, 6(1), 5. ↩︎
Ebrall, P. (2020). THE CONVENTIONAL IDENTITY OF CHIROPRACTIC AND ITS NEGATIVE SKEW. Journal of Contemporary Chiropractic, 3(1), 111–126. ↩︎
Members of the Canadian Chiropractic Guideline Initiative, Bussières, A. E., Zoubi, Al, F., Quon, J. A., Ahmed, S., Thomas, A., et al. (2015). Fast tracking the design of theory-based KT interventions through a consensus process. Implementation Science, 10(1), 591. ↩︎