An image of a man holding his sore shoulder and neck area is used to illustrate the concept of painful trigger points.

Myofascial trigger points (MTrPs) have been observed and written about for centuries, but the idea that they cause a significant percentage of commonly experienced pain has achieved little acceptance in the medical community until very recently.

Janet Travell, MD, was motivated by her own shoulder pain to explore a novel method of relieving pain by injecting procaine hydrochloride into tender spots in muscles in the late 1930s1. She found that by injecting a tender spot in her posterior shoulder, she could eliminate pain that she was experiencing in her anterior deltoid. She wrote her first paper on this new approach, which would eventually be referred to as myofascial trigger-point therapy, in 19422.

Travell and her collaborator, David Simons, MD, wrote the definitive textbooks on trigger- point therapy, the two-volume “Trigger Point Manual” 3. These books were an impressive achievement, but their audience was confined to medical practitioners, with procaine injection being the primary method of therapy; manual therapy was barely mentioned.

Injection was only usable by licensed medical practitioners, most of whom have neither the time nor the muscular anatomy and palpatory training to adopt a practice that requires highly accurate injections in sites throughout the body, sometimes in endangerment areas, with many overlapping muscular, vascular and neurological structures.

For these and other reasons, trigger-point therapy has remained a minor player in the manual therapy industry. If massage therapists’ school curriculum covers MTrPs at all, they are generally taught simple ischemic compression of MTrPs with no coverage of joint movement, neurological distraction or key refinements like satellite referral and functional relationships.

MTrP therapy has largely been relegated to minor status, as yet another modality that works sometimes but not most.  This is an extremely unfortunate situation, because properly trained therapists with robust techniques and analytical skills have a high degree of success in remediating even difficult chronic pain conditions.4

The Pain Industry

It is no secret that the pain industry has been an enormous failure, and that patients in chronic pain are dramatically underserved.5 Primary care physicians and pain specialists routinely rely upon pain medication, including opioids, and invasive, dangerous surgeries. In 2020 alone, deaths from opioids reached an all-time high of 100,000, and many of the victims were first introduced to opioids via prescriptions, became addicted and then sought out street drugs.4

At the heart of the medical system’s failure to adequately diagnose and treat pain is an old, embedded belief that most pain is caused by such disruptions external to the brain as injury or disease. In this worldview, the injury or inflammation causes the pain, and the misguided conclusion is to look for an injury at the site where the patient perceives their pain.

However, the insights of modern neuroscience and trigger-point studies thoroughly debunk this belief. Myofascial Pain Syndrome (MPS), or pain caused by MTrPs, is far more common than current practice assumes, but proper diagnosis of MPS requires specialized training that remains relatively rare among primary physicians.5

Phantom Limb Pain Disrupts Neuroscience

Phantom limb pain provides a fascinating perspective on the true origins of pain. Ninety-five percent of amputees experience an ongoing sensation of the missing limb still being present and actually feel pain in the area where the limb would have been. Neuroscientist V.S. Ramachandran, in a brilliant insight, posited that the brain’s map for the missing limb was disturbed because the limb could no longer be moved or provide proprioceptive input to the brain.

Basically, the brain remained “stuck” in the injured state of the arm pre-amputation. So, he hypothesized that if he could trick the brain into believing that the limb was still attached, he could help a patient find relief.6

Ramachandran devised an experiment in which he used a simple mirror that created for the brain the illusion that the missing limb was present and healthy. His hope was that by processing this visual information, it would lead the brain to neuroplastic change, correcting its own model of the arm as a working, intact limb and alleviating the experience of pain.

This experiment was extremely successful, and he was permanently able to eliminate the phantom pain in some of his patients, as long as they stuck with it for a period of weeks or months.

Ramachandran was the first major researcher to posit that the brain controls the sensation of pain, “an opinion on the organism’s response to health rather than a reflexive response to injury.7” The brain establishes its assessment of danger through integrating such inputs as emotion and stress with nociceptive inputs, which are not pain signals, but danger signals produced by nociceptive organs distributed throughout the periphery when they detect the presence of inflammatory compounds. In Ramachandran’s model, pain is an output, not an input.

Is This Dangerous, Really?

Lorimer Moseley, DSc, PhD, professor of clinical neurosciences and chair in physiotherapy at the Sansom Institute for Health Research at the University of South Australia and a collaborator of Ramachandran’s, states that soft tissue damage is neither necessary nor sufficient for the experience of pain.8

This disconnection of causality places into serious question your doctor’s assumption that a familiar pattern of wrist and hand pain is due to carpal tunnel syndrome. Even if damaged or diseased tissue were the only source of nociception, the brain’s decision to generate an experience of pain is independent of that.

However, there is another very significant source of nociception that has nothing to do with disease or injury—nociception from MTrPs. The authors and editors of the third edition of“The Trigger Point Manual” write that even in the absence of tissue damage, MTrPs “function as persistent sources of nociceptive input and contribute to peripheral and central sensitization,” as well as neuroplastic change characteristic of chronic pain.9

The Proof is in the Tissues

Jay P. Shah, MD, a senior staff physiatrist and clinic researcher at the National Institutes of Health, has devoted his career to understanding the physiology of MTrPs and how they interact with the CNS. Using microtubules—essentially hollow acupuncture needles—he has sampled the chemical milieu of MTrPs in muscle and discovered excess concentrations of several inflammatory compounds known to stimulate muscle nociceptors in both active (producing referred pain) and latent trigger points.10

MTrPs commonly develop in the presence of acute or chronic overload. In the case of both MTrPs and amputee patients months after surgery, injury is no longer present. MTrPs aren’t gross injuries; they are cell-level disturbances that are often easily cleared by the body. However, the presence of pro-inflammatory chemicals creates a sort of false-flag operation, impersonating injury or disease to the central nervous system.

The Hidden Trickster

Shah’s discovery that latent MTrPs still send a stream of nociception to the CNS even though they don’t refer pain is quite important. Latent MTrPs are far more common than active, are present in satellite referral chains (where the referral pattern of one muscle causes dysfunction in another) and could support ongoing chronic pain by flooding the CNS with hidden danger signals, like the unseen below-water mass of an iceberg.

In the presence of an ongoing stream of peripheral danger signals, the brain tends to upregulate, increasing synaptic connections and sensitivity (Niddam et al., n.d.). This can set up chronic pain that has no obvious basis in tissue damage or disease, something seen very commonly in severe chronic pain clinics.11

Many MTrPs have a pain referral pattern that is felt directly over joints and tendons, and often mimics the radiating patterns of neurological impingements such as radiculopathy. Given the lack of knowledge of trigger-point phenomena in the medical profession, misdiagnoses are very likely, when practitioners attempt to explain referred pain through an assumption of injury or disease in the area where pain is experienced.

My own clinical experience over the last 20 years has shown me that even when presented with diagnoses such as bursitis, tendinitis, spinal impingement, arthritis and many others, it is highly likely that trigger-point therapy will be effective. Several studies support the idea that much of the pain presented in clinical situations is due to trigger points.

In a study of 110 adults with low-back pain, myofascial pain was the most common finding, affecting 95.5% of patients.12 A study of adult migraine sufferers diagnosed according to International Headache Society criteria showed that 94% of the patients reported familiar migraine pain with manual stimulation of cervical and temporal MTrPs, compared with only 29% of controls. In 30% of subjects, manual palpation of related trigger points brought on full-blown migraines.

Moving Toward More Accurate Diagnosis

The results seen in survey studies of MTrP prevalence are likely to underestimate the true prevalence of trigger-point pain due to gaps in diagnostic technique among primary care providers as well as secondary pain specialists. Relatively few medical practitioners have enough specific muscular palpation training to reliably diagnose pain from MTrPs, leading to low inter-rater reliability.

Myofascial pain syndrome (MPS), or pain due to MTrPs, is now recognized as a valid clinical diagnosis by members of the American Pain Society13 and is estimated to affect 85% of the population,5 yet MPS was identified as the most common missed diagnosis in a 1993 study of chronic pain patients involved in litigation.14 

A 2017 study evaluated treatment outcomes in 997 pain patients using an experimental secondary care model employing five primary care providers who had been trained in pain management as well as specific musculoskeletal medicine.5 The latter included specific practical training in the diagnosis and treatment of MPS using several modalities, including dry needling, injection and manual therapy.

With intake conducted by these skilled providers, 82% of the 997 patients were diagnosed with MPS. Significant long-term improvement was observed in 75%, using simple, inexpensive MPS treatment modalities—a number that stands in stark contrast to typical outcomes in chronic pain treatment by providers who are not trained in MPS.5

Academic investigation of MTrPs and MPS is very slowly catching up with the undeniable and compelling experiences of well-trained trigger-point therapists. Much more investigation is needed to solidify the biochemical and neurological pathways behind MPS, including direct and satellite pain referral, and to document evidence-based guidelines for treatment and insurance coverage.

The massage therapy industry would be well-served to include more specialized training in MTrP theory and manual techniques specific to MPS. This would allow therapists to serve the vast numbers of clients who seek out pain relief every day from their massage therapist, often having been failed by the medical system.

Conversely, primary care providers trained in MPS diagnosis could refer far more patients to MPS-qualified massage therapists, allowing them an exit from the deadly cycle of chronic pain, addiction to pharmaceuticals and failed invasive intervention. 


1. Travell J. “Office Hours: Day and Night” (Ex-Library edition). The World Publishing Company. 1969.

2. Travell J, Seymour R, Myron H. “Pain and disability of the shoulder and arm: treatment by intramuscular infiltration with procaine hydrochloride.” Journal of the American Medical Association. 1942; 120 (6): 417–22.

3. Travell J, Simons D. “Myofascial Pain and Dysfunction, Vol. 1: The Trigger Point Manual, The Upper Extremities” (1st Edition). Baltimore: Williams & Wilkins. 1982.

4. Duff C.  “Ending Pain: Coaching the Body with Neuroscience, Movement and Trigger Point Therapy.” Houndstooth Press. 2022.

5. Fogelman Y, Carmeli E, Minerbi A, Harash B, Vulfsons S. “Specialized Pain Clinics in Primary Care: Common Diagnoses, Referral Patterns and Clinical Outcomes – Novel Pain Management Model.” Advances in Experimental Medicine and Biology.2018; 1047: 89–98.

6. Ramachandran VS. “The Tell-Tale Brain: A Neuroscientist’s Quest for What Makes Us Human” (Reprint edition). New York: W.W. Norton & Company. 2012.

7. Doidge N. “The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science” (first edition). New York: Penguin Books. 2007.

8. “50 Shades of Pain with Prof. Lorimer Moseley | Trust Me, I’m a Physiotherapist.” n.d. Accessed April 17, 2021.

9. Donnelly JM, Fernández-de-Las-Peñas C, Finnegan M, Freeman JL. “Travell, Simons & Simons’ Myofascial Pain and Dysfunction: The Trigger Point Manual” (3rd edition). Philadelphia: LWW. 2018.

10. Shah JP, Gilliams EA. “Uncovering the Biochemical Milieu of Myofascial Trigger Points Using in Vivo Microdialysis: An Application of Muscle Pain Concepts to Myofascial Pain Syndrome.” Journal of Bodywork and Movement Therapies. 2008; 12 (4): 371–84.

11. Doidge N. “The Brain’s Way of Healing: Remarkable Discoveries and Recoveries from the Frontiers of Neuroplasticity.” New York, New York: Penguin Books. 2016.

12. Dommerholt J, Bron C, Franssen J. “Myofascial Trigger Points: An Evidence-Informed Review.” Journal of Manual & Manipulative Therapy.2006 14 Oct; 203–21.

13. Dommerholt J, Grieve R, Layton M, Hooks T. “An Evidence-Informed Review of the Current Myofascial Pain Literature–2015.” Journal of Bodywork and Movement Therapies. 2015 Jan; 19 (1): 126–37.

14. Hendler NH, Kozikowski JG. “Overlooked Physical Diagnoses in Chronic Pain Patients Involved in Litigation. Psychosomatics.” 1993; 34 (6): 494–501.

Chuck Duff

About the Author

Chuck Duff has spent the last 20 years developing and training therapists in Coaching The Body®, which integrates a new understanding of MTrP theory and practice with modern neuroscience and techniques from Thai bodywork. His new book, “Ending Pain,” is a number-one Amazon Bestseller. He can be reached at