Monday, March 27, 2017

Trigger Points & Myofascial Pain Syndrome

Cartoon of a man stooped over and facing away, with several signs stabbed into his back. The signs have toxic waste hazard waste symbols on them, representing the fact that there is evidence that trigger points are “toxic.”

Does your body feel like a toxic waste dump?
It may be more literally true than you realized! Some evidence shows that a knot may be a patch of polluted tissue: a nasty little cesspool of waste metabolites. If so, it’s no wonder they hurt, and no wonder they cause so many strange sensations: it’s more like being poisoned than being injured. Back pain is the best known symptom of the common muscle knot, but they can cause an astonishing array of other aches and pains. Misdiagnosis is much more common than diagnosis.

Trigger Points & Myofascial Pain Syndrome

Toxic Muscle Knots

Research suggests myofascial trigger points may be quagmires of irritating molecules

What is the chemistry of a muscle knot? Specifically, what’s the condition of the tissue fluids in and around them?

The science of myofascial trigger points has been dominated for years by the theory of a poisonous feedback loop, a vicious cycle. The idea is that knots generate a lot of tissue fluid pollution, waste products of muscle cells that are metabolically “revving” with intense contraction … and those “exhaust” molecules then accumulate, mostly causing pain, which irritates the trigger point even more.

Gerwin RD, Dommerholt J, Shah JP. An expansion of Simons' integrated hypothesis of trigger point formation. Curr Pain Headache Rep. 2004 Dec;8(6):468–75. PubMed #15509461.
The most well-known explanation for the trigger point phenomenon is the “expanded integrated hypothesis,” which was first presented in this 2004 paper. It’s harrowingly detailed and technical, and mostly just filled in some details missing from the original integrated hypothesis (“a possible explanation”), which was put forward by Travell and Simons in 1999, which was in turn an elaboration on the energy crisis hypothesis that debuted in the first edition of their famous red textbooks in 1981. This has been a work-in-progress for quite a while. Here’s a simplified translation of the expanded integrated hypothesis:

Under some circumstances, muscular stresses can cause patches of poor circulation, which results in the pooling of noxious metabolic wastes and high acidity in small areas of the muscle. This is both directly uncomfortable, but also causes a section of the muscle to tighten up and perpetuate a vicious cycle. This predicament is often called an “energy crisis.” It constitutes a subtle lesion. TrPs research has largely been concerned with looking for evidence of a lesion like this.

Ingeniously measuring

muscle knot molecules
Starting with a simpler study in 2005, and then a more thorough one early this year, a group of scientists using “an unprecedented, most ingenious, and technically demanding technique” have reported that there really are irritating metabolic wastes floating around the neighbourhood of trigger points: “… not just 1 noxious stimulant but 11 of them,” Dr. Simons explains. “Instead of just a few noxious chemicals that stimulate nociceptors [nerves endings that detect tissue damage] nearly everything that has that effect was present in abundance.”
The researchers analyzed tissue samples from in and around trigger points and compared it with samples from healthy muscle tissue. The differences were significant.
If they are right, the muscle tissue at the location of trigger points appears to be just rotten with irritating molecules: molecules associated with inflammation, with pain, and with immune function.
Diagram of energy crisis hypothesis diagram, very simple.
Extremely over-simplified diagram of the energy crisis hypothesis, which occurs in a tiny patch of muscle. Right or wrong, it’s been kicking around for a decades now.

Feel the burn! Are muscle knots acidic?

Personally, I was pleased to see evidence that trigger points are also strongly acidic. I guessed that this might be the case in about 2002. (The pioneer of trigger point research, Dr. Janet Travell, had already suggested the same thing, but I didn’t know it then.) I often told my patients that trigger points were “acidic,” because it seemed likely to be true and because … well, it just sounded good, I guess. Lucky for me, this new research now gives some strong support to that old opinion. It doesn’t prove it, but it’s certainly noteworthy.
Trigger points really are strongly acidic which means that, for instance, it is actually plausible that deep breathing — which lowers blood acidity slightly — might be relevant to treatment. One of the possible goals of massaging trigger points is to “flush” trigger points by physically pushing stagnant tissue fluids out of the area of a trigger point, sometimes called “blanching.” Perhaps if fresh, less acidic blood re-perfuses the area, the trigger point will recover more easily? It’s a reasonable guess.

On the other hand, all that could be wrong wrong wrong

We shouldn’t accept the results of this experiment at face value simply because it seems to confirm an idea much beloved by massage therapists. Rubbing trigger points is probably not “detoxifying” — that’s not what this research suggests, even if it’s correct. Which it isn’t necessarily.
In a complicated and very technical experiment, it is all too easy for researchers to find the result that they want to find.

I think that’s exactly what happened in a popular study supposedly showing that massage reduces inflammation, a related idea. This is why independent confirmation from other experiments is always essential. As of fall 2016, this research has still not been replicated as far as I know. And it has been criticized and dismissed by some. So take it all with a grain of salt for now.

Rubbing trigger points is probably not “detoxifying” — that’s not what this research means, even if it’s correct.

More muscle knot reading (lots more)

Professionals are strongly encouraged to read David Simons’ analysis of both the new evidence about the chemistry of energy crisis in trigger points, as well as another new scientific article on the use of magnetic resonance elastography (MRE) imaging — a promising new way of taking pictures of muscle knots.
Simons writes that this technology “may open a whole new chapter in the centuries-old search for a convincing demonstration of the cause of trigger point symptoms.”

Trigger point therapy is not a miracle cure for chronic pain — but it helps

Trigger point therapy isn’t “too good to be true” — it’s just ordinary good. It’s definitely not miraculous. It’s experimental and it often fails. Good trigger point therapy is hard to find (or even define).

But it’s also under-rated, and self-treatment has the potential to quickly, cheaply, and safely help with many common pain problems that don’t respond well — or at all — to anything else.

For beginners with average muscle pain — a typical case of nagging hip pain or low back pain or neck pain — the advice given here may well seem almost miraculously useful. I get avalanches of email from readers thanking me for pointing out simple treatment options for such irritating problems. Many are stunned by the discovery that their chronic pain could have been treated easily all along.

For veterans who have already tried — and failed — to treat trigger points, this document is especially made for you. You should learn more and try more before giving up. This will get you as close to a cure as you can get; I can give you a fighting chance of at least taking the edge off your pain. And maybe that is a bit of a miracle.

Attention physicians & therapists: This massive tutorial is written for both patients and professionals. It includes analysis of recent research that you won’t find in any text, crafted to suit any skill level. Footnotes add a optional layer of advanced detail that you can take or leave.

Trigger points are more clinically important than most health professionals realize, and body pain seems to be a growing problem. It’s a rewarding topic for doctors and therapists, that makes clear path to helping quite a few people you probably couldn’t help before. Even if you already know about myofascial pain syndrome, you will get new ideas here.

What exactly are muscle knots?

When you say that you have “muscle knots,” you are talking about myofascial trigger points.

There are no actual knots involved, of course — it just feels like it. Although their true nature is uncertain, the main theory is that a trigger point (TrP) is a small patch of tightly contracted muscle, an isolated spasm affecting just a tiny patch of muscle tissue (not a whole-muscle spasm like a “charlie horse”). In theory, that small patch of muscle chokes off its own blood supply, which irritates it even more — a vicious cycle called a “metabolic crisis.” The swampy metabolic situation is why I like to think of it as sick muscle syndrome.

A few trigger points here and there is usually just an annoyance. Many bad ones is a syndrome: myofascial pain syndrome (MPS).

TrPs can be vicious. They can cause far more discomfort than most people believe is possible. Its bark is much louder than its bite, but the bark can be extremely loud. It can also be a surprisingly weird bark (trigger points can generate some odd sensations).

A “muscle knot” is a trigger point: a small patch of muscle tissue in spasm.

A humourous graphical definition/translation of the jargon myofascial pain syndrome.

Why muscle pain matters so much

Muscle pain matters: it’s an important problem. Aches and pains are an extremely common medical complaint, and trigger points seem to be a factor in many of them. They are a key factor in headaches (possibly including migraine and cluster headaches as well), neck pain and low back pain, and (much) more. What makes trigger points clinically important — and fascinating — is their triple threat. They can:

1. cause pain problems,

2. complicate pain problems, and

3. mimic other pain problems.

Muscle just hurts sometimes. Trigger points can cause pain directly. Trigger points are a “natural” part of muscle tissue. Just as almost everyone gets some pimples, sooner or later almost everyone gets muscle knots — and you get pain with no other explanation or issue.

It’s complicated. Trigger points complicate injuries and other painful problems. They show up like party crashers. Whatever’s wrong, you can count on them to make it worse, and in many cases they actually begin to overshadow the original problem.

“It felt like a toothache.” Trigger points mimic other problems. Many trigger points feel like something else. It is easy for an unsuspecting health professional to mistake trigger point pain for practically anything but a trigger point. For instance, muscle pain is probably more common than repetitive strain injuries (RSIs), because many so-called RSIs may actually be muscle pain. A perfect example: shin splints.

The daily clinical experience of thousands of massage therapists, physical therapists, and physicians strongly indicates that most of our common aches and pains — and many other puzzling physical complaints — are actually caused by trigger points, or small contraction knots, in the muscles of the body.

Why are trigger points so neglected by medicine?

“Muscle is an orphan organ. No medical speciality claims it.” Muscle tissue is the largest organ in the body, complex and vulnerable to dysfunction, and the “primary target of the wear and tear of daily activities,” nevertheless “it is the bones, joints, bursae and nerves on which physicians usually concentrate their attention.” Family doctors are particularly uninformed about the causes of musculoskeletal aches and pains — it simply isn’t on their radar. They are busy with a lot of other things, many of them quite dire. As serious as muscle pain can be, it’s minor compared to, say, diabetes or heart disease. And it’s also a harder topic than it seems to be on the surface. So it’s not really surprising that doctors aren’t exactly muscle pain treatment Jedi.

What about medical specialists? They may be the best option for serious cases. Doctors in pain clinics tend to know about trigger points. But they also often limit their treatment methods exclusively to injection therapies — a bazooka to kill a mouse? — and anything less than really epic chronic pain won’t qualify you for admittance to a pain clinic in the first place. This option is only available to patients for whom trigger points are a truly horrid primary problem, or a major complication. Medical specialists may know quite a bit about muscle pain, but aren’t all that helpful to the average patient.

An appallingly high percentage of doctors and other practitioners are still pretty much out of the loop regarding trigger points.

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