The Bullsh*t Detector -Round 3: Trigger Point Therapy

Not that long ago I had a fairly severe case of plantar heel pain, which was embarrassing for a podiatrist!

I did all the right things, taped, tweaked my orthoses, DiGiovanni stretching, I got a bottle of tonic water, mixed it with gin, drank that, then refilled it with water, froze it, and rolled it over my painful heel.

That worked brilliantly, for an hour…

 

Meanwhile, my colleague and good friend Brenton, who is a qualified acupuncturist, fixed me with a smile, no make that a smirk, and eventually beckoned me into his treatment room.

There he identified a “trigger point” in my lateral gastrocnemius, stuck a needle into it, gave it a bit of a twirl, and BINGO, my heel pain disappeared,

And guess what? It has never come back!

So what kind of wizardry was this Brenton had applied?

A recent photo of Brenton

 

Trigger points are a fantasy, a figment of someone not invested in evidence-based treatment, as everyone knows. This was simply an N=1 and must be discounted as a probable placebo.

There simply is no evidence that they even exist…

Or, is there?

Paul Ingraham is a pain scientist and skeptic, and I love reading his evidence-based posts at painscience.

Recently I was browsing through one of his blogs where he really zooms in on the very difficult question of trigger points, but before we launch into that, I learned a term I was not familiar with.

 “Presumptive treatment” is a term I probably should know, but did not! However.. I like it!

“Presumptive Treatment” is based on educated diagnostic gambling: It might be a trigger point, so let’s treat it like one and see what happens.

Presumptive treatment goes on constantly in the real world,  think about the way we treat plantar heel pain. It looks like plantar fasciitis, it smells like plantar fasciitis, so we assume it IS plantar fasciitis and treat it presumptively WITHOUT ever making an actual diagnosis!

 

And, importantly, treatment success does not confirm what the problem was.

Now looking specifically at trigger points and trigger point therapy.

The main issue has always been that the diagnosis has generally been made by “feel” or palpation, and this has been widely criticized by some experts. Skeptics have pointed to the lack of evidence that trigger point therapy works, the lack of a reliable physical exam to identify trigger points in the first place, inadequate evidence that there is even anything to find, and all of this even after several decades of research — an existentialist crisis.

However, that said, we should take a step back, because the same comments could be made for so many of the conditions we treat. Think “shin splints”, still so called because we STILL do not know what the heck it is, but we think we do and we treat it presumptively! And remember, we make this diagnosis by palpation, just like trigger points!

So, in clinical settings, rigorous confirmation of lesions often never actually happens, even in the case of some dramatic and “obvious” pathologies.

And yet, we continue to have much higher expectations for trigger point therapy and other “unproven therapies”! Medicine is weird!

OK, so what are trigger points, and what causes them?

The answer to the cause is simple, we have absolutely no idea!

The answer to the second is becoming clearer because as we march on in the 21st Century our diagnostic testing and imaging skills have improved dramatically.

A physical examination can’t tell us if a pathology exists and how it works.

So what is a trigger point? A muscle lesion, a spasm, a contracture?

Well I will quote directly from Paul Ingraham’s excellent article which may be read in full here

 


Contracture, not spasm 

‘Calling the lesion a “tiny spasm” is poetry, not science. A spasm is actually a neurologically mediated contraction — that is, there’s nothing wrong with the muscle tissue itself (it’s just doing what the nervous system is telling it to do). Hypothetically, a trigger point is a lesion in muscle tissue, specifically a non-neurologically mediated contracture’


 

For direct evidence of any lesion, we have to turn to histology and imaging.

Four categories of histologic and imaging evidence provide direct support for a muscle lesion associated with the clinical phenomenon of a trigger point. Although that evidence is imperfect and incomplete, much of it is good quality, and all of it is consistent with the integrated hypothesis of trigger points.

  1. Biopsies and photomicrographs of trigger points.
  2. Scans of trigger points using new imaging technologies, especially elastography.
  3. Measuring the abnormal electrical signature of trigger points (“endplate noise”).
  4. Samples of the acidic, “toxic” tissue chemistry of trigger points.

The myofascial trigger point hypothesis postulates that there are small foci of contracted sarcomeres in resting skeletal muscle. Although there exist only a handful of published studies including a biopsy of a trigger point (including animal studies), the evidence is pretty compelling.

The studies to date have identified foci of segmentally contracted sarcomeres in human subjects, consistent with the hypothesis of trigger point formation and with the presence of trigger point end plate noise.

Indeed, the study by Reitinger et al in which biopsies were performed of palpable nodules (presumed to be trigger points) in the gluteus medius muscles, showed enlarged and darkly-staining muscle fibers — swollen fibers with higher oxidative capacity (more mitochondria, basically) — compared to elsewhere in the muscle.

Histology of human trapezius muscle in myofascial trigger points (MTrPs) samples and control samples. Muscle was stained with haematoxylin-eosin (H&E) (a,b,e,f) and Masson stain (c,d,g,h) in MTrP samples (a–d) and control samples (e–h). Normal muscle cells were observed in the control group (e). Enlarged, round, contracted muscle (black arrow) was observed in MTrPs patients (a)(From: https://onlinelibrary.wiley.com/doi/full/10.1002/ejp.1647)

 

Elastography, a specialised kind of ultrasound imaging that can identify taut bands of muscle tissue containing focal nodules appears even more conclusive.

At least three recent studies produced good evidence of stiff (“tight”) tissue at the location of suspected trigger points.

Example of the trigger point area ROI. MTrP = myofascial trigger points; ROI = regions of interest; TPz = trapezius; TE = left upper trapezius.  (from: https://www.semanticscholar.org)

The electrical signature of a trigger point is called endplate noise or spontaneous electrical activity (SEA). End plate potentials (EPPs) are the waves of electrical activity that spread out from the point where motor neurons attach to muscles (which have a distinctive saucer-like appearance). We can measure this with EMG, either surface mounted or fine wire.

We only have two small but straightforward studies, both clearly finding EPPs at supposed trigger points.

Finally, is there any evidence for a tissue chemistry basis to trigger points?

There are 3 studies, with the research trail running cold way back in 2011, However, all three studies showed tissue fluid in and around a trigger point with molecules associated with metabolic exhaustion and pain (pH, bradykinin, substance P, calcitonin gene-related peptide, tumor necrosis factor alpha, interleukin 1beta (IL-1beta), IL-6, IL-8, serotonin, and norepinephrine)… which is what we’d expect to find if the main theory of how trigger points work is correct.

It must be noted that one of these studies was performed on rabbits, and humans are not rabbits!

So what is the wash? Bullsh*t detected or not?

Painscience summarises as follows:

The above evidence is good enough for a moderate degree of confidence that:

  1. the general hypothesis that the clinical phenomenon known as “trigger points” is indeed associated with some kind of muscle lesion
  2. the lesion has characteristics that are consistent with the more specific “integrated hypothesis” that it’s essentially a small contracture

and so I am going to call this a viable treatment option, especially if we use the presumptive therapeutic model with informed consent, i.e., no bullshitus!

What is for certain is that trigger points and trigger point therapy is crying out for more research so we can better understand how to identify and treat these lesions!

Please visit https://www.painscience.com/ for more information on trigger points and a whole world of other useful information!

Now.. I wonder if trigger points can occur in fascia……?

 

Written by

Simon Bartold

Founder and Director

Bartold Clinical

 

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One response to “The Bullsh*t Detector -Round 3: Trigger Point Therapy”

  1. Simon,
    on your final point about the fascia, I’m sure Ian Linane has bent your ear on this subject! What are your thoughts on this subject and the body of evidence behind it?

    I will admit I have a dog in this fight as I have done the course and use this regularly in my practice.

    Best wishes,
    Glen

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