Spinal Manipulative Therapies: Long-term Effectiveness

In part I of this series I talked about myths associated with methods used alongside spinal manipulation (and got fired because of it). In part 2 (not available in english) I discussed research on the short-term effects of spinal manipulations (tl;dr: pain relief, maybe some range of motion improvements). In this third installment I’ll discuss the long-term effectiveness of spinal manipulation treatments.

Most people seeking physiotherapy aren’t looking to receive a palliative therapy for the foreseeable future, they view it as curative – a part of really getting better.

Answering a question such as “do spinal manipulations work?” is a fairly complex endeavor. When doing a randomized trial one needs a large group of people to demonstrate a small treatment effect, but a small group will suffice to demonstrate a large treatment effect. It’s fairly easy to establish a very large treatment effect on an otherwise stable condition (like thyroid hormone therapy where there is no placebo effect on serum hormone levels). So the fact that this question is still even being asked  today already implies that spinal manipulations likely have a small or non-existing treatment effect. Basically, if they worked really well for a significant number of people (i.e. they worked as well as spinal manipulative therapists will tell you), one would only need a couple of medium or small sized studies to settle the issue.

Further, if one follows two groups of people who have a condition that is unstable – people frequently improve on their own, or get worse on their own – it’s fairly likely that the groups will be unequal at the end, regardless of interventions. Large powerful intervention studies are expensive, and so only a few of them are performed. Small studies with conflicting results give little or no information individually, but allow cherry-picking the data. So those small studies need to be combined into a meta-analysis, and it’s one of these that I will center this discussion around, a study published in 2014, authored by Menke.

A meta-analysis like this pools the treatment effects from multiple clinical trials and uses statistics to compare interventions. The strength of the Menke analysis is in how inclusive of studies it is (more difficult to cherry-pick), and the fact that he does a comparative analysis of different treatment groups from spinal manipulation trials. His analysis is highly informative and extremely interesting, even if the paper is in many ways unorthodox. The main conclusion to be drawn from the paper, sorry for the spoiler, is that spinal manipulative therapies provide no overall benefits long-term.

I will present here some key points from his analysis, that help to answer the question of how well spinal manipulations work clinically in the long-term. I say clinically, because there is a great paradox of why these therapies remain popular despite the evidence of their ineffectiveness and their weak theoretical foundation. Some parts of his analysis reveal components of the “formula for success” of how and why spinal manipulative therapists thrust cash in their pockets.  The interested reader is of course advised to read the original meta-analysis.

#1 – A waiting list is significantly worse than doing nothing.

Most treatment groups had comparable results if they were manipulations or electrotherapy or what have you. But treatments that required any human contact outperformed those without human contact. People put on a waiting list (a waiting list control) were the only group that worsened in the short term. So it’s better to purposely do nothing than to wait for a therapy. It’s reasonable to assume from this that going from a waiting list to any intervention at all will always result in an improvement, so a waiting list is a good strategy to improve patient satisfaction without improving treatment effects.

#2 – The effect size of spinal manipulations remains unchanged since the first trials

Menke converts the results of individual studies into effect sizes  which may be compared between studies – think of effect sizes as a unit of comparison – this is similar to converting pounds and stones into kilograms to compare people’s weights. What this reveals is that the effect sizes of spinal manipulation have remained the same from when trials on them started. Improved study quality, better health care, MRI etc. have not lead to a bigger effect of the spinal manipulations. As spinal manipulation outcomes are unchanged despite better research and healthcare, it’s reasonable to assume that they will be unchanged in the foreseeable future as well.

#3 – The prognosis is actually good, with or without interventions

One of the difficulties in researching back pain treatments is that the condition is unstable. This means that spontaneous improvements are common, and the pain and disability vary greatly due to natural fluctuations throughout the year. Most people seek treatments (and register into clinical trials) at their worst, and will then improve regardless of the intervention. So for this reason, most interventions that cause little or no direct harm will have good clinical results.

#4 – Spinal manipulation success has the same statistical chance as a throw of the dice

If treatment wings within trials were classified according to whether or not they outperformed sham treatments, the chance of spinal manipulations being the best treatment was equal to a throw of dice where the sides on the dice equal the treatment arms. Two treatment arms – 50% chance. Three treatment arms – 33% chance, etc.

When two treatments are compared on an unstable condition with small groups, it would be expected that the groups were unequal at the end of the study despite treatments. Any treatment under study needs to outperform this natural variability to show any meaningful results. Spinal manipulations fail to do this.

#5 – It makes no difference who performs the manipulation, or how, or why

In 30+ years of spinal manipulation research, no group of therapists has proven more effective than another. They’ve tried chiros, physios, bonesetters, you name it. It also makes no difference if the specific technique is chosen by the therapist based on an examination or by a researcher based on nothing.

#6 – Out of all the comparison groups, only one intervention stands out

You guessed it. Exercise. Something which actually has a demonstrable long-term effect on how the body functions is the only intervention that works better than sham therapies, including manipulations. It may not matter much which type of exercise or training system is chosen, but it’s important to get the patient moving. This is in-line with most clinical guidelines for treatment of back pain (1), so it’s hardly surprising.

Discussion

Strength:

While being far from conclusive for all patients, under all circumstances at all times the Menke article has many strengths to it. The biggest in my mind is that it answers one very important clinical question that is worth emphasizing:

If a person with low back pain decides on his/her own to see a therapist that does spinal manipulations, the results will be in line with Menke’s review.

Recent research in spinal manipulative therapy has come up with clinical prediction guidelines to predict which patients respond most favorably to spinal manipulations (1). Applying these guidelines must be done clinically, preferably by the first contact doctor or physio. If the person sees a spinal manipulative therapist first, the benefit will be non-existent.

Limitation:

It would not be fair of me to only discuss the strengths of the review without any of the limitations. The review does not discriminate between patient groups. It’s possible that future studies will identify means to effectively apply spinal manipulations, perhaps due to clinical prediction rules or sophisticated use of emerging technology such as ultrasound imaging. However, the key point remains that currently the lack of long-term effectiveness of spinal manipulative therapies are largely known for the broad strokes of clinical populations.

The blog post that got me fired

If posted under different circumstances, the title of this post would be: „Spinal manipulation – is it a precise science?“. Within a day of posting this, I was given two weeks notice. I’ve done my best to keep the tone and presentation as close to the Icelandic version as I can, even if the English suffers a bit. I’m not dressing this up any fancier, just because of the circumstances under which I post.

When I originally wrote this, I was very much political about it. I made a special effort to identify areas where manipulations may be useful, and make a point of not directly recommending that patients don’t receive them. The main purpose was to first point out some limitations to the methodology behind them in this article and follow through with the mechanisms of action, and ultimately their effectiveness as an only therapy in future articles.

I’ve made comments [in brackets] that are intended as a supplement or explanation to the english reader, and those were not included in the original article.

So without further ado:

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Spinal manipulation – is it a precise science?

A memorable story I once heard involved a practitioner of some sort performing some sort of motion palpation when his wrist cracked. This prompted his client to say „ahhh… just what I needed!“. I don’t know if this story is true or not, but spinal manipulations are certainly very sought after treatments in Iceland – and unfortunately many confuse popularity for effectiveness.

Professionally I’ve met many individuals who have had a poor experience with spinal manipulations, be it from chiropractors, physios, bonesetters, or osteopaths. Many of them have booked countless treatment sessions and spent considerable money without getting any real improvements. Some are unsure if the treatment has been effective or not, others are certain that it was useful.

Still, the fact of the matter is, there are many myths around about the techniques associated with spinal manipulations. I’m going to take a look at some of the research that’s been done on spinal manipulation methods: how precise they are, if they can alter the position of joints in the spine, and if choosing the right manipulation technique is important.

Spinal manipulations aren’t precise

Many believe it’s possible to influence to a large degree which spinal joints to manipulate, for example to manipulate adjacent segments to a disc herniation. Studies have been performed to test this theory using sensitive vibration sensors placed on various segments to locate the source of the „pop“ sound. The results of these suggest that for the lumbar spine, only about half the manipulations hit the targeted joint, despite most of them manipulating more than 1 segment (1). If the target may be defined as either the upper or lower lumbar spine, accuracy improves up to 70% (2), and one is pretty certain to hit the correct half (left or right) most of the time. So, if one wishes to *not* manipulate a certain segment, the safest would be to at least have a 3 segment safety margin.

Spinal manipulations don’t alter joint position

Sometimes x-rays are used to support decision making for spinal manipulations where the therapist is looking for a misaligned segment to correct with a manipulation. It actually kind of amuses me that it’s no problem to take a diagnostic x-ray, but the second x-ray to verify the changed alignment is usually too much radiation…

Thankfully, not everyone has a problem with that second x-ray to confirm that at least sacroiliac joint manipulations don’t change sacroiliac joint alignments (3). The study used manual positional testing / motion palpation that diagnosed abnormal position of the joint before manipulation, and a correct alignment after the manipulation – but with no change in the actual position of the joints on x-rays. It remains an open question [this line included a link to another blog post I wrote about motion palpation, not translated at this time] what these motion palpation tests are actually testing.

I’m not aware of compatible studies on lumbar joint positions. The closest I could find was this study that used MRI’s to assess the height of the facet joint space before and after manipulations. The MRI was taken immediately after the manipulation, before the patient could get up from the therapy bench – so the significance of the change they found is uncertain. (4)

The giant’s bite [directly translated for amusement], when there’s a sudden onset of back pain with a restricted range of motion is very painful and can be quite scary. No one has yet confirmed the mechanism behind such sudden range of motion loss, although numerous theories exist. Further, there are no studies directly on the effects of manipulations of joints in this state or if they reverse whatever is causing the loss of range of motion. I don’t see any obstacles to trying out manipulations on this patient group.

You don’t need a detailed examination to select the proper manipulation technique

A meta analysis (5) examined if there was a difference in outcomes between studies where the practitioner can select the manipulation technique used, or when the technique is chosen beforehand by the researchers and found there was no difference at all. The results suggest that the method chosen, or the methods used to select the proper technique probably matter very little if at all. A study on cervical spines did not find a correlation between cervical range of motion as measured, and as palpated to be hypomobile by a therapist (6) [the link #6 in the Icelandic version links to a different article by mistake, I’m here linking the correct one] – so using such techniques to select joints to manipulate is likely meaningless anyway. I’ve previously discussed [link to Icelandic blog post] if motion palpation can be useful, and the short answer is no – long answer in link.

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These three myths are a source of a number of theories about trying to find the right technique for the right person. There is no data to back any of that up, only hundreds of years of tradition and guesswork. Only recently has it been possible to adequately study these methods with sensitive measures like imaging, but the results so far all point in the same direction: if you are going to manipulate a spine, just go ahead and manipulate a spine. No real need for a complex examination scheme beforehand.

A second installment of this article series will discuss the effects of spinal manipulations on the body, and if there’s a reason to use those effects as part of treatments. A third article will discuss the long-term clinical effectiveness of spinal manipulations on low back pain. [I include this last paragraph about planned future articles only for completeness, the second one is already published and the third one nearly complete, but they are in Icelandic]


So that was it. I’m sure (or perhaps I hope?) that readers will find this less inflammatory than they had anticipated (or hoped?). It certainly could have been more direct in it’s message, and I think it would have made a better article that way as well since the parts about possible benefits of manipulations stray away from the direct topic at hand. But while I wrote this, I was very much mindful of those reading it.

How blogging about physiotherapy research can get you fired

Recently, a blog post I wrote about limitations of spinal manipulation got me fired!

Somehow that doesn’t surprise me, maybe that’s just what happens when you rattle some dinosaur cages. A dinosaur in physiotherapy is someone who is stuck in the past, and refuses to update his/her views with new evidence unless it feeds their confirmation bias (1). It’s obviously not a technical term, but a valid description that I am by no means the first one to blog about (2). It’s also not a blanket description of everyone that graduated before me. It’s not the age that defines the dinosaur, but rather the attitude. There’s plenty of physios with many years of experience that still remain open to new ideas and evolve their practice to reflect these ideas.

Dinosaurs and their followers are very prevalent today, even among the young folk who work with and are influenced by the older ones. It’s only in recent years that evidence based physiotherapy is flourishing, facilitated by the explosion of research (3) coupled with social media that allows the open discussion, criticism, and dissemination of information by physiotherapists (4).

And, naturally, the dinosaurs are pissed. Not only has almost every therapy they have been providing failed the test, but the whole paradigm of why these treatments should work has failed. Dinosaurs are too deeply committed to these outdated ways of thinking to objectively evaluate the science, too married to old ideas to divorce them. To them, decades of consistent research can be brushed off with “you can feel it working”, or “It’s been working for years!”, or even the abysmally short-sighted “I have a waiting list so I must be doing something right”. They are in an endless loop of using temporary analgesic effects to justify unnecessary or even harmful treatments, confusing immediate patient satisfaction with good clinical outcomes and consciously forcing patients in dependency instead of promoting self-efficacy.

So when I challenged the dinosaur viewpoint by pointing out that there are important limitations to spinal manipulation, I got fired.

Icelandic physiotherapy is undergoing a silent crisis, and in my opinion dinosaurs are causing it. The average out-patient physio in Iceland sees ~5,5 patients per day (5), which is less than a full time job. Some of the more popular ones see 18+ patients per day, which means that at the lower end are physios who hardly see any patients at all.

Seeing 18 individual patients per day can’t be considered ethical practice. That means working 9 hours straight, without a break, every day. Making decisions and staying focused becomes difficult (6). It gets more and more tempting to just do the easiest thing, and that often includes providing passive analgesic therapies. Using active treatments and engaging the patients in a therapeutic union takes presence of mind and concentration. I would sure not like being patient number 18.

Discussing treatment options and prognoses – real prognoses, not a unicorn story – may end up with a patient deciding not to attempt an intervention. And that’s ok, people have a right to accept or decline any medical treatment plan. It is our job as physiotherapists to provide patients with the best possible information regarding their condition and work with them to tailor a treatment plan. This may include various therapies if indicated and the patient chooses to use them after discussing it with the physio. But sometimes, this includes one of the hardest decisions a physio makes: recommending no intervention at all.

Other times this may include something unpopular, such as recommending that a patient skips a competition or a planned trip. In that situation, it’s our job to provide the patient with information regarding possible risks associated with participation, but the patient usually makes the final decisions, after all it’s their risk. If the therapist is greed-driven, working from a business model of more sessions per patient = better, these are surely worthless strategies. In that case, it’s much better to tell the patient „we’ll do everything in our power to make that trip!“ and proceed to throw every therapy under the sun at the patient and hope for the best.

Dinosaurs have indeed become good at milking as many treatment sessions as possible out of every single patient that walks through their door. They take their money by spending countless sessions fixing imaginary blocked sacroiliac joints, softening up tight muscles, and telling stories about remarkable single-session quick fixes.

The same udder-squeezing skill-set results in increasing numbers of patients who realize they spent considerable time and money for little benefit. This in turn creates people who are skeptical about physiotherapy, and will just stop booking sessions. It’s a vicious cycle of over-treating causing decreasing numbers of sessions, resulting in increased over-treating.

Evidence based physiotherapy is – compared to the bloated dinosaur therapy – streamlined, resource-efficient and requires much fewer treatment sessions on average. It’s a scalpel next to a chainsaw. It’s a breath of fresh air next to a garbage dump. Even the popular dinosaurs can smell the change coming, and they are stressed enough over it to fire people like me for making the patient better informed.

Even patients that receive a fake therapy, literally a machine that is turned off, will still improve with treatments (7). This means that every physio will get apparently decent outcomes by simply being equal to the passage of time and a machined turned off. The goal is to provide the patient with information about their condition and the efficacy of possible treatments. Every intervention attempted should have a good chance of performing better than time, and to that end it’s so important to use the research evidence to weed out the useless therapies and set reasonable treatment goals. If no treatment is indicated – the patient will receive information regarding his condition, but no voodoo tricks.

The trend is to increasingly emphasize evidence-based physiotherapy in physiotherapy education. It’s also increasingly emphasized that the knowledge gap between science and the public should be bridged by communicating findings to the public. I got fired for just that, discussing information and evidence – evidence the dinosaurs obviously want to sweep under the rug so they can remain complacent and their clients blissfully ignorant. I believe more physios need to openly support evidence-based physiotherapy and speak up against these outdated methods and together we just might be the meteor that saves physiotherapy.