We have all experienced a tight muscle that causes pain and restriction of motion, such as sleeping on our neck wrong, but this is not myofascial pain syndrome (MPS) . So, just what is MPS?
Myofascial Pain Syndrome
The primary job of a skeletal muscle is to provide locomotion by attaching to other muscles and to joints. When knotted up pieces of muscle fiber called trigger points develop, the muscle is shortened and becomes dysfunctional. Myofascial trigger points (TrPs) prevent normal contraction and relaxation of the muscle involved. These self-sustaining nodules in the hyper-irritable area of the muscle causes sensory, motor, and autonomic symptoms.
- Myofascial: pertaining to the covering (fascia) of muscle
When TrPs are not treated early and appropriately, the tug and pull of the dysfunctional muscle fibers creates stress and leads to development of more TrPs in either the same muscle, compensatory muscles on the same or opposite sides of the body, or in all four quadrants of the body as our musculoskeletal system perpetually tries to adjust.
Diagnosing Myofascial Pain Syndrome
Diagnosis can be complicated if the examiner is not familiar with MPS. Myofascial disorders are generally poorly understood in the medical community. April 2018 research alleges MPS may be confused with fibromyalgia, because both MPS and FM are prominent forms of chronic musculoskeletal pain in their literature review. This delays proper treatment.
A history of chronic myofascial pain, muscle pain, and joint dysfunction is what usually gets us to the doctor. As previously noted, MPS pain and dysfunction usually occurs in more than one quadrant of the body and includes:
- Pain that lasts three to six months
- Trigger points that can usually be felt by the examiner
- A taut muscle band. (You may or may not be able to feel the TrP in the band depending on the amount of muscle contraction. There may be one or more in the same muscle.)
- Referred pain (A referral pattern for the TrP is consistent between patients. Pain can be well away from the primary trigger point.)
- Twitch response of the muscle by some mechanical method (i.e. manual pressure or needle insertion).
- Decreased mobility related to the affected muscle
- Weakness in the affected muscle
Myofascial pain syndrome is known as “the great imitator,” and with good reason. For instance, MPS involving the piriformis muscle (a small deep muscle that cuddles the sciatic nerve) may be misdiagnosed as sciatica.
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Myofascial Pain Syndrome and Fibromyalgia
Many of the conditions known to cluster with FM, like severe headache, restless leg syndrome, teeth grinding, balance problems, TMJ, chronic pelvic pain, chest wall pain, and more have a myofascial component of their own. Pain specialist, Karl Hurst-Wicker, MD, explains it like this in a 2018 interview :
“There is a good deal of overlapping between MPS and fibromyalgia (FMS). Likely this is related to the consistent long-term activation of peripheral pain pathways causing central [nervous system] sensitization and other changes in the nervous system that contribute to the development of FMS. Conversely, it can work in the other direction too; a patient with a primary FMS can develop MPS, in no small part because the FMS can amplify and perseverate even minor myofascial pain and injury to the point where it can propagate and become a regional issue.”
Unlike FM, MPS is not gender prevalent. Many of the perpetuating factors are genetic, such as short upper arms, short lower legs, one leg shorter than the other, curvature of the spine, or other musculoskeletal deformities. Some metabolic dysfunctions are thought to perpetuate myofascial pain syndrome, too. People with skeletal structural defects, both inherited or the result of injury, surgery, post-polio syndrome, or poor posture, and people who experience undue stress on a muscle, including repetitive motion, can contribute to MPS.
What We Can Do
Treatments for myofascial pain syndrome include manual treatment by a certified myofascial trigger point specialist , a physical therapist or chiropractor that specializes in myofascial therapies, guided self-treatment, electrical stimulation, ultrasound guided trigger point injections  by a pain specialist, and more. But, the best treatment is prevention. We should be aware of perpetuating factors, so we can avoid them or manage them as best we can.
Consistent diagnostic criteria that can be used by all healthcare professionals is needed to ensure patients get the right diagnosis and the right treatment in a timely manner. Both MPS and FM cause pain , but that pain is not the same. Myofascial pain is a peripheral nerve problem that can usually be isolated; FM is a central nervous system problem that causes body-wide sensitivity.
Perpetuating factors of MPS can, and do, vary among us. Some of us may have a genetic disorder like joint hypermobility.  We may have both MPS and FM. Some of us work at computers, and yes, I must remain astutely aware of my body positioning. Maybe you had a surgery that left you with scarring of tissue that puts a strain on normal movement. There are a myriad of things that can lead to development of chronic myofascial pain. But, the important thing to remember is that trigger points are treatable, and the longer we go without addressing the problem, the greater the risk to developing trigger points that seemingly breed like rabbits and become resistant to treatment.
This article was first published on ProHealth.com on January 7, 2019 and was updated on January 14, 2021.