In the world of pain and discomfort, one often encounters the term "Myofascial Trigger Points" or MTrPs. However, this concept is surrounded by debates, uncertainty, and many treatment options. In this blog post, we aim to simplify Myofascial Trigger Points, exploring what they are, their history, and shedding light on the controversies surrounding their diagnosis and treatment.
What are Myofascial Trigger Points?
Myofascial Trigger Points, commonly referred to as trigger points, are specific, focal areas within taut bands of skeletal muscle that become hyperirritable. These points are known for causing both local and referred pain. They often accompany various musculoskeletal disorders and can be associated with metabolic, visceral, endocrine, infectious, and psychological conditions.
A Brief Historical Perspective:
The exploration of nodules or thickened spots in muscles and fascia dates back centuries. The early 19th century saw vague associations, but it was not until the works of Ralph Stockman in the late 1800s that a more defined understanding emerged. He suggested that fibrocytic nodules harbored low-grade inflammation, activating sensory fibers and causing muscle spindle and interstitial tissue involvement.
The term "myofascial trigger point" was later coined by Janet Travell and David Simons, who emphasized that these trigger areas could perpetuate pain cycles indefinitely. Their influential work, particularly the two-volume "The Trigger Point Manual," formalized the diagnosis of Myofascial Trigger Points.
Here are 5 things to know about trigger points:
1. Uncertainty Surrounding Trigger Points
The presence of trigger points in various conditions raises questions about whether they are associated findings, causal elements, or essential for effective treatment.
There is a questionable association between trigger points and myofascial pain. As the authors of this paper stated, "We do not currently know if MPS is only due to trigger points, or if MPS is an independent pain condition." Current data doesn't explain whether their disappearance is crucial for pain relief. At this stage, they can very much be like asymptomatic disc herniations that sometimes are not the cause of back pain they are generally attributed to be.
2. Inflammation in Trigger Points
Studies by Shah et al. have indicated elevated levels of inflammatory markers in active trigger points. However, these markers were also found in uninvolved muscles, suggesting inflammation might not be exclusive to trigger points but could result from tissue damage or altered peripheral nerve function.
Simply said, inflammation that usually causes pain is present not only around trigger points but also in not painful areas of the body, suggesting alternate causes of inflammation as mentioned above rather than just arising from the trigger points.
3. Postural Influence
Trigger points are often associated with overuse and muscle overload, particularly in postural muscles. The Cinderella Hypothesis suggests that small motor units, named "Cinderella units," are susceptible to prolonged contractions, leading to an energy crisis. The debate continues with conflicting evidence on whether postural muscles, in general, are more vulnerable.
However, in postural muscles; during slow and adjusting contractions (as their function) motor units are recruited by rotation rather than by size allowing sequential shift-like relaxation phases, thus suggesting that relaxation time is an important factor to be considered.
Thus, a weak muscle under load (overload) probably is more susceptible, not postural muscles in general. (here)
4. Challenges in Diagnosis
The diagnostic gold standard for Myofascial Trigger Points involves a manual examination, including palpation of taut bands, identification of tender nodules, and the reproduction of symptomatic pain. However, this method relies heavily on the examiner's skills and lacks reliability when blinded to the diagnosis, raising questions about its effectiveness as a defining criterion.
5. Neurogenic Inflammation
Recent studies propose a new explanation for Myofascial Trigger Points, suggesting that the peripheral nervous system communicates with the immune system to create neurogenic inflammation. This perspective sheds light on the biochemical findings in trigger point zones and also makes the practice of breaking TPs down by the use of manual force/ golf ball or any other instrument/ dry needling useless.
Treatment Dilemmas:
A multitude of treatments for Myofascial Pain Syndrome (MPS), including Myofascial Trigger Points, have been proposed. Non-invasive interventions such as compression, spray and stretch, and transcutaneous electrical stimulation, as well as invasive treatments like injections and dry needling, are common, though whether there is a need to treat trigger points remains questionable since they are probably neither causative nor diagnostic.
However, controversies arise, particularly with invasive modalities. Systematic reviews find limited evidence for the specific effectiveness of needling therapies. Questions linger about the heterogeneity of treated populations, the lack of standardized diagnostic criteria, and the variability in research methodologies.
The final question delves into the psyche of clinicians who swear by the effectiveness of certain treatments, particularly needling therapies. The "Post hoc ergo propter hoc" (meaning "after this, therefore because of this") fallacy, where the effects of needling are attributed solely to the act of needling rather than contextual factors, might explain the anecdotal responses to these treatments.
(Read our blog to know the potential mechanism of action of dry needling and other similar therapies)
Contextual factors, including accompanying therapies and patient expectations, play a significant role. The "Illusion of Validity" suggests that patients may perceive effectiveness due to a relationship between two things, even if the connection is unclear.
In Summary, Myofascial Trigger Points remain a captivating yet enigmatic phenomenon in the realm of pain. As we navigate the uncertainties and controversies surrounding their diagnosis and treatment, it is essential to approach the topic with a curious and questioning mind.
Read the detailed version of this blog here.
Photo by RDNE Stock project
Disclaimer: In the presence of pain all the structures and context must be clinically assessed, this blog is in no way a substitute for a clinical assessment and all must consult a physiotherapist or a physician in such conditions.
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