I have previously mentioned some of the background but, somehow, I seem to have omitted to draw your attention to the actual paper. Yes, I am talking of the review of cervical manipulation prepared for the Manitoba Health Professions Advisory Council. It is an important and well-researched document; even though it is already a few months old, I feel I must correct my omission.

Here is the abstract:

Neck manipulation or adjustment is a manual treatment where a vertebral joint in the cervical spine—comprised of the 7 vertebrae C1 to C7—is moved by using high-velocity, low-amplitude (HVLA) thrusts that cannot be resisted by the patient. These HVLA thrusts are applied over an individual, restricted joint beyond its physiological limit of motion but within its anatomical limit. The goal of neck manipulation, referred to throughout this report as cervical spine manipulation (CSM), is to restore optimal motion, function, and/or reduce pain. CSM is occasionally utilized by physiotherapists, massage therapists, naturopaths, osteopaths, and physicians, and is the hallmark treatment of chiropractors; however the use of CSM is controversial. This paper aims to thoroughly synthesize evidence from the academic literature regarding the potential risks and benefits of cervical spine manipulation utilizing a rapid literature review method.

METHODS Individual peer-reviewed articles published between January 1990 and November 2016 concerning the safety and efficacy of cervical spine manipulation were identified through MEDLINE (PubMed), EMBASE, and the Cochrane Library.


  • A total of 159 references were identified and cited in this review: 86 case reports/ case series, 37 reviews of the literature, 9 randomized controlled trials, 6 surveys/qualitative studies, 5 case-control studies, 2 retrospective studies, 2 prospective studies and 12 others.
  • Serious adverse events following CSM seem to be rare, whereas minor adverse events occur frequently.
  • Minor adverse events can include transient neurological symptoms, increased neck pain or stiffness, headache, tiredness and fatigue, dizziness or imbalance, extremity weakness, ringing in the ears, depression or anxiety, nausea or vomiting, blurred or impaired vision, and confusion or disorientation.
  • Serious adverse events following CSM can include the following: cerebrovascular injury such as cervical artery dissection, ischemic stroke, or transient ischemic attacks; neurological injury such as damage to nerves or spinal cord (including the dura mater); and musculoskeletal injury including injury to cervical vertebral discs (including herniation, protrusion, or prolapse), vertebrae fracture or subluxation (dislocation), spinal edema, or issues with the paravertebral muscles.
  • Rates of incidence of all serious adverse events following CSM range from 1 in 10,000 to 1 in several million cervical spine manipulations, however the literature generally agrees that serious adverse events are likely underreported.
  • The best available estimate of incidence of vertebral artery dissection of occlusion attributable to CSM is approximately 1.3 cases for every 100,000 persons <45 years of age receiving CSM within 1 week of manipulative therapy. The current best incidence estimate for vertebral dissection-caused stroke associated with CSM is 0.97 residents per 100,000.
  • While CSM is used by manual therapists for a large variety of indications including neck, upper back, and shoulder/arm pain, as well as headaches, the evidence seems to support CSM as a treatment of headache and neck pain only. However, whether CSM provides more benefit than spinal mobilization is still contentious.
  • A number of factors may make certain types of patients at higher risk for experiencing an adverse cerebrovascular event after CSM, including vertebral artery abnormalities or insufficiency, atherosclerotic or other vascular disease, hypertension, connective tissue disorders, receiving multiple manipulations in the last 4 weeks, receiving a first CSM treatment, visiting a primary care physician, and younger age. Patients whom have experience prior cervical trauma or neck pain may be at particularly higher risk of experiencing an adverse cerebrovascular event after CSM.

CONCLUSION The current debate around CSM is notably polarized. Many authors stated that the risk of CSM does not outweigh the benefit, while others maintained that CSM is safe—especially in comparison to conventional treatments—and effective for treating certain conditions, particularly neck pain and headache. Because the current state of the literature may not yet be robust enough to inform definitive prohibitory or permissive policies around the application of CSM, an interim approach that balances both perspectives may involve the implementation of a harm-reduction strategy to mitigate potential harms of CSM until the evidence is more concrete. As noted by authors in the literature, approaches might include ensuring manual therapists are providing informed consent before treatment; that patients are provided with resources to aid in early recognition of a serious adverse event; and that regulatory bodies ensure the establishment of consistent definitions of adverse events for effective reporting and surveillance, institute rigorous protocol for identifying high-risk patients, and create detailed guidelines for appropriate application and contraindications of CSM. Most authors indicated that manipulation of the upper cervical spine should be reserved for carefully selected musculoskeletal conditions and that CSM should not be utilized in circumstances where there has not yet been sufficient evidence to establish benefit.


I think this is a balanced review, not least because the authors stress that further research is required to strengthen evidence for efficacy of CSM for treatment of neck pain and headache, as well as for other indications where evidence currently does not exist (i.e., upper back and shoulder/arm pain, high blood pressure, etc.).

The review expresses many of the concerns and cautions that I have repeatedly tried to voice on this blog. I have no means of telling who the authors of this document are, but I applaud their thorough research, their clear language, and their courage to publish. For all who have a deeper interest in upper neck manipulation, I strongly recommend to study the report in full detail.


  • Indeed, a well-balanced conclusion.
    We at the Israeli Chiropractic Society devoted our entire annual meeting last year to discuss cervical spinal manipulations risk assessment and safety issues. we had lectures by vascular surgeons and other clinicians to discuss the different possible side effects and dangers. We had an open debate on the clinical efficacy of manipulations vs. mobilizations etc.

    My OWN conclusions were:
    1. The literature in that case is of very poor quality for many reasons we can discuss.
    2. There are many precautions measures we as clinicians can and should take in order to minimize adverse events especially such that involve non-vascular accidents. This is to do mainly with clinical decision making regarding the use of CSM and the adaptation of the techniques to the potential risk factors in each case.

  • you are correct, we as a society can educate and influence but we have no legal status. as such we can not pursue anyone and we can not do much more than educate and convince.

    however, since we are in the process of legistlation with the Israeli MOH we presented to them an ethical code that demands a responsible practice with evidance base and reasoning at its core.

    Also part of the requirments are that each new Chiropractor will practice under supervision in a general hospital for 6 months and pass an MOH exam.

    we hope and believe this will improve and promote the profession and public health and safety.

    this is not something that has been forced upon us this is in our intrest to improve.

  • i can assure you non of the Chiropractors working at my hospital unit or my practice will ever make such claims or practice in such manner. as far as the ICS we can argue and educate but we can not exclude someone from membership (unless of course an ethical complaint has been filed and exhusted such has happened in few rare cases).

    i will try and find the invite for this seminar we had and send you a copy.

    • I find it hard to believe that you cannot exclude someone from membership; if the ICS is clear that chiropractic is nor about curing diseases and that chiros who claim otherwise behave unethical. surely any professional organisation must exclude unethical members.

    • I am interested to here that in Israel chriros are partly trained in a hospital under supervision and also work in hospital units. In UK chiros go nowhere near hospitals for their training and work in independent unregulated practice rather than in an NHS evidence based, accountable setting. How can a patient in UK possibly be protected from any potential danger from CSM?

      • I think it was an American neurologist who found the answer to your question when stating: DON’T LET THE BUGGARS TOUCH YOUR NECK!

        • so I guess he is not one of the many neurologists that refer patients with headaches to see me?

          I do appreciate the professional language though

    • Is it ethical to claim ‘subluxations’ are ‘adjusted’, when there is no plausible reproducible evidence that is the case?

  • @ Edzard

    I wonder if the following review was done by the same people as the review you have sited in this blog:

  • “…A number of factors may make certain types of patients at higher risk for experiencing an adverse cerebrovascular event after CSM, including…atherosclerotic…”

    An interesting study just came out, of course after the above mentioned review.

    Effects of Cervical Rotatory Manipulation on Internal Carotid Artery in Hemodynamics Using an Animal Model of Carotid Atherosclerosis: A Safety Study.

    CONCLUSIONS: Both the rotational angle and the atherosclerotic disease can affect the blood flow of the ICA. However, CRM does not cause adverse effects on hemodynamics in cynomolgus monkeys with mild CAS, and appears to be a relatively safe technique.

    • @DC
      I have been looking into Internal Carotid Injury (ICA) and possible causal mechanical links with manipulation of the C-spine. What I have started suspecting is that it may not be the HVLA-rotatory forces that are at play in post-manipulation ICA lesions. Instead I think it may be simultaneous application of digital pressure over the ICA that happens to compress it and cause dissection or intramural hematoma. This is just a theory and will probably remain so forever as the phenomenon is extremely rare and not amenable to research that can substantiate causality. As with vertebral artery injury, evidence will always be limited to observational data.
      I have looked at a multitude of such manipulations in YT-videos, happily provided by chiropractors as marketing material. In many of them I see them applying pressure with a thumb antero-laterally, exactly where the ICA is positioned.

      Comments on this speculative hypothesis of mine are appreciated.

      • Bjorn. I can only respond based upon the videos I have seen online and often my response is…WTH are they doing?

        Regarding pressure on the ICA, it’s an interesting thought. This paper just came out, may be of interest.!po=43.3333

        • @DC, thank you for the link. I am afraid this (too small) study has little bearing on the question at hand. It concerns the angle of the carotid bifurcation and its influence of the risk of plaque rupture in that area, an interesting question that is difficult to see the clinical value of.
          My hypothesis is that finger pressure over the ICA near the skull base may injure the internal carotid artery. This happens somewhat higher than the bifurcation. Such pressure, if it compresses the artery directly may disrupt an atherosclerotic artery wall and even injure a young, healthy artery. Ehlers Danlos syndrome and similar predisposing conditions would increase such risks.

          • I am not familiar with a maneuver that risks digital pressure on the ICA.

          • @DC
            If you take a close look at how the manipulator presses with his thumb at 2:56 – 2:58 in this video, you will perhaps understand what I have in mind. The link starts the film at 2:54.
            This is just one of many examples I have found in YT videos that show a chiropractor/manipulator placing and pressing his thumb where it might compress the ICA.

          • @Björn Geir
            If that were the case why are MMA fighters in the octagon and weekend warriors training in gyms around the world not dropping like flies? They are using extreme force on the neck in their choke holds.

          • Bjorn. Got it. Sloppy technique. No idea of the effect this would have on the ICA but I will share it with the 15,000 + chiropractors I’m in contact with and inform them to watch that thumb position.

          • You tell me CC.
            I am simply trying to understand how a causal mechanism might be. There is a multitude of reports from different parts of the world, of cervical artery injury at or shortly after cervical manipulation. This can NOT be ignored because of the risks involved. This fact HAS to be respected and evaluated in relation to the benefits of neck manipulation. The best evidence says the risk/benefit ratio is unacceptable.
            My view, that I share with others is that if neck manipulation was a drug, it would be retracted with immediate effect.

            As I said before we will never be able to establish with certainty a causal relationship other than observational data of rare events.
            I see by DC’s response that my efforts have already had an effect that just possibly might save a few cervical arteries by making chiropractor aware of the remote possibility that their thumb or other finger exerts sudden concentrated pressure on an artery, which may rarely start a bleeding between the layers of the arterial wall or/and a tear in its inner lining, i.e. a dissection. Not all such events lead to serious consequences but the rare one’s that do can be devastating.
            Your comparison to strangleholds in fighting competition is irrelevant unless you show a) that a sudden compression occurs over a small area (fingertip) on the carotid artery and b) that the incidence of ICA injuries is nill in events where a) occurs.

          • @BG
            Interesting systematic review though for the vertebral artery just published.
            Vertebral Artery Dissection in Sport: A Systematic Review.
            If you look at the description of the various choke holds I am as mystified as you as to why they are not suffering from serious adverse events.
            A search for ICA and sport:
            Sports-related internal carotid artery dissection: pathogenesis and therapeutic point of view.
            Internal Carotid Artery Dissection in Brazilian Jiu-Jitsu

            Your hypothesis is interesting.
            Could it actually be sustained pressure causing localized hypercapnia and vasodilation?

  • The last sentence of the quote states: “CSM should not be utilized in circumstances where there has not yet been sufficient evidence to establish benefit.”

    In what circumstances has sufficient evidence been accumulated to establish benefit?

    • if I may answer this one: NONE.

    • What is considered as “sufficient evidence”?

    • Bjorn: In what circumstances has sufficient evidence been accumulated to establish benefit?“

      What evidence did these authors consider? Are they wrong in their analysis? If so, why was this published?

      “When compared with oral analgesics, cervical manipulation and/or mobilization appears to provide better short-term pain relief and improved function in patients with neck pain. Manipulative therapies may be as effective as amitriptyline for treating migraine headaches and can reduce the frequency and intensity of pain.”

  • All the apologists and believers use arcane phrases such as: “when thrust manipulation is deemed warranted…”
    “When testing indicates hypomobility…”. “Exorcism is deemed necessary when sufficient evidence of satanic possession is established…beyond a reasonable doubt”. Stuff like that.

  • I just found your site and I wish I had found it sooner. I am suffering now from the effects of a neck manipulation done by a chiropractor. I had gone to the chiropractor because of lower back pain. She put me on a kind of “whole body” plan to fix my posture and my entire skeletal system, which she said was not aligned properly. The first few sessions went well and I felt better, particularly my lower back. We combined these treatments with exercises for core support, which also seemed to be helping.

    About ten days ago, she did a high velocity neck adjustment. I felt ok the first day afterward, but the following day I started to have headaches and felt numbness at the top of my head. The numbness felt like I could not control my muscles. I was worried I might be having a stroke or some other complication, so I went to a hospital ER and they examined me and ordered a CT scan, which they said did not indicate any problems with blood flow or any tears in my arteries. So that’s great. But my head is still numb and not improving, and now it spreads to my face. I told my chiropractor that this is happening, and she responded that “some people do not tolerate high velocity low amplitude cervical adjustment well and do experience your symptoms.” Her advice was to put ice on my neck and do gentle movements with it! Like this will solve the problem! She now also recommended traction of the cervical spine, which as I understand it, is used to treat cervical injury. So I went into the chiropractor with no neck injury, and I left with terrifying symptoms of numbness and pressure on my head, and no solution from my chiropractor. I now have no idea what to do, and I feel so stupid for not doing research before allowing a chiropractor to go anywhere near my neck.

    Anyway, thank you for your website in revealing the dangers of this profession to unsuspecting people who, like me, naively believed that this had to be safe since there are colleges of chiropractic and there is a “dr” next to these people’s names.

    • please see a proper doctor asap

    • Nathan

      Your story is not uncommon, I have heard of this happening with others, I’m sorry to hear. That said, I have heard worse stories from friends also. I have a co-worker that told me his wife went in for back surgury, and now she has no feeling below her waist. She doesn’t know when to pee or poo…. so she wears a bag. It gets worse. As it turned out, the surgury was expermental, the patients were not informed of any experiment. Twenty-two of the twenty-six women that had the same surgury ended up with the same result. The AMA suspended his liscense for five months, now he is back practicing medicine (literally). The doctor was taken to court for monetary judgements, the AMA brought in “expert” witnesses to testify on his behalf. The ruined patients are getting nothing from him…. just the shaft.

  • @DC: yes those 15,000 can come over for an intimate dinner, drinks and casual sciency conversation at your house.They can palpate each other and all find a different “lesion” to mobilize…and notice 1/3rd feel better for a few minutes, 1/3rd feel worse and a 1/3rd suspect the whole thing is a big charade but are afraid of getting beat up if they mention it. A big shindig of non-specific & placebo effects pretending to be important advances in “healthcare”. Gypsys are a great role model…as is the Catholic Church and the confessional. My grandmother would make an elaborate point of proclaiming how much lighter, happier, holier and healthier she felt as she emerged from the holy-box.

    • Actually, total membership of the groups is around 27,000 but i figure alot of crossover so i estimated around 15,000 individuals.

      I could post in a couple other groups of mainly TORs to reach another 10,000 or so chiropractors but they tend not to like me.


    As of April 5, 2019, the manitoba chiropractors launched legal action (two years later)against the College of Physicians and surgenos for the CPSM’s report to the government’s Health Professions Advisory Council’s Report on the risks of high neck manipulation. Statement of claim included in this link.

    • Many thanks for this very interesting link Patricia.
      What is glaringly obvious is that the statement of claim contains no material argument contradicting the substance of the CPSM report, which is simply a non-judgmental assessment of a possible serious health risk related to cervical manipulation. This lawsuit is nothing but a lame, ill-advised attempt to intimidate and silence. I dare guess that it will be thrown out when the judge realises that public interest and safety overrides the terms of a 16 year old agreement about mutual respect and cooperation, if I understand right.
      A lawsuit instead of evidence is practically an admission of having no defence.

  • Bjorn…A lawsuit instead of evidence is practically an admission of having no defence.

    Maybe they should have referenced this paper?

    Chaibi A et al. A risk-benefit assessment strategy to exclude cervical artery dissection in spinal manual-therapy: A comprehensive review. Ann Med. 2019 Mar 19:1-27.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Subscribe via email

Enter your email address to receive notifications of new blog posts by email.

Recent Comments

Note that comments can be edited for up to five minutes after they are first submitted but you must tick the box: “Save my name, email, and website in this browser for the next time I comment.”

The most recent comments from all posts can be seen here.