Myofascial Trigger Points
For those of you who have been treating patients and addressing myofascial trigger points (MTrPs) for 20 years or longer, you may remember a day when a diagnosis of trigger points were considered to be "alternative" or "hippie" medicine. "You think my patient has what?" was a common response from many physicians when told about trigger points. Getting health care providers to understand the concept of referred pain with relation to the muscular system was like trying to teach a lion to hate steak.
In recent times, however, there have been some interesting discoveries that are actually backed by good, solid science. Shah et al showed myofascial trigger points by using ultrasound vibration sonoelastography (VSE) which uses an external vibration source in conjunction with Doppler techniques. MTrPs vibrated at a different resonance than the surrounding "normal" tissue making trigger points appear as focal, hypoechoic regions on 2D ultrasound. This imaging technique helped the researchers determine that MTrPs are elliptical in shape, with a size of 0.16 ± 0.11 cm2.1
"But what is happening inside the purported myofascial trigger point?" you may ask. Shah et al gives us an understanding about this. In their paper, the researchers were able to gather extremely small amounts of fluid and determined that concentrations of protons, bradykinin, calcitonin gene-related peptide, substance P, tumor necrosis factor-alpha, interleukin-1beta, serotonin and norepinephrine were significantly elevated in active myofascial trigger points compared to controls.
We can image trigger points. We know they are different internally. How do we assess? Trigger points are best identified and treated when a practitioner follows a specific protocol that not only takes trigger points into consideration as a pain generator, but also other medical conditions that may be responsible for the pain complaint. In other words, they should be included in your differential diagnosis/assessment. Remember that trigger points can be a primary source of pain or secondary due to visceral disease, joint dysfunction, parasitic infection, systemic disorders and others, which is generally more apparent when response to therapy is negligible or transient.
First, a thorough history should be taken. Travell emphasized the importance of this step by saying, "The mystery is in the history." Patients should be instructed to provide a chronology of events that led up to the onset of their condition being sure to include all previous medical diagnoses (regardless of perceived relevance), a listing of all medications, nutritional supplements and any current lab and diagnostic imaging studies.
She said patients should provide dates and places of residence, education, marriages, children living (ages and where they live), sports, travel and employment (what kind, where, for whom). Chronology of medical events should include all illnesses, infections, accidents (e.g., fractures, falls), surgical procedures, pregnancies and miscarriages, allergies (tests and hyposensitizations) and vaccinations.3 She mentions that trigger points are aggravated by elevated histamine levels and active allergies. Testing the skin for dermatographia by marking it is a simple way to identify high histamine levels, according to Travell.
Patient Interview (The History)
When talking to patients about their pain, the practitioner should do two things. First, the patient should be instructed to use one finger and outline the areas of pain while the practitioner documents the described pain on a pain map. Secondly the practitioner should ask specific questions about the other areas of the body that the patient did not mention. This will help determine if there was ever pain in other places, which could indicate a myofascial condition that preceded the complaint with which the patient is presenting.
Discussing the patient's dietary intake is also of importance. Simply asking patients if they eat a "balanced diet" is not always a good practice. Many times patients will state that they are eating well despite having serious diet restrictions, most often vegetarianism. When a patient is not consuming meats, fowl, fish or dairy products, they are at high risk for vitamin deficiencies, including but not limited to deficiencies in iron, vitamin D, B12, etc. Many times the onset of pain can be related to a time that is soon after a dietary change where these types of restrictions are initiated.
Discuss the profession of the patient to determine the types of muscle strain that may occur. Have patients snap a picture of their workstation and include it with their history information. Some practitioners may ask for patients to get a picture taken while they are working. A picture can immediately identify a situation that can cause muscular strain and essentially explain the condition. Use similar techniques when looking at any activity with which the patient spends considerable time, including sports and hobbies.
Although it is possible for trigger points to cause constant pain, more often than not the pain is intermittent and aggravated by specific movements. Many people have found that certain positions can alleviate their trigger-point pain and unknowingly avoid certain movement due to the pain produced while moving through range of motion. Generally, pain from trigger points is described as steady, deep, dull and aching, and rarely as burning or throbbing. Occasionally, trigger-point pain is described as sharp or "lightning-like" stabs of pain.3 Referred tenderness is also a symptom where the area that is sensitized is extremely painful to the lightest palpation, especially when multiple trigger points refer to one area or in a naturally sensitive zone of the body.
Be as specific as possible in questioning. I can recall a situation where I noticed fasciculation of muscle as I was working with a client and also noticed that he was extremely fidgety and talked fast. I looked at the intake form I used at the time that asked about caffeine intake, and the client checked the box next to coffee and listed "one cup." I asked again about coffee, and he confirmed his "one cup" as on the form. Because it really wasn't relevant to me at that time, I let it go. When he came in the next time presenting as even more fidgety, I laughed and asked, "How BIG is that cup?" The client went out to his vehicle and brought in what looked like the coffee dispenser in a convenience store! I immediately changed the "how much" part of my intake to ask for ounces consumed.
This article is the first of three. The next two will discuss medical perpetuating factors for myofascial pain due to trigger points, and useful treatment techniques and self-treatment.
1. Sikdar, S., Shah, J., et al. (2009). Novel applications of ultrasound technology to visualize and characterize myofascial trigger points and surrounding soft tissue. Archives of Physical Medicine and Rehabilitation, 11(90), 1829-1838.
2. Shah, J., Phillips, T., Danoff, J., & Gerber, L. (2005). An in vivo microanalytical technique for measuring the local biochemical milieu of human skeletal muscle. Journal of Applied Physiology, 5(99), 1977-1984.
3. Simons, D., Travell, J., & Simons, P. (1999). Travell and Simons' Myofascial Pain and Dysfunction: The Trigger Point Manual. Vol 1. Upper Half of Body. 2nd ed. Baltimore: Williams and Wilkins.
Jeffrey A. Lutz is board certified in myofascial trigger-point therapy and has two offices in western Pennsylvania. He is president-elect of the National Association of Myofascial Trigger Point Therapists, an organization of therapists who specialize in trigger-point therapy (www.MyofascialTherapy.org) and is the technical writer for www.TriggerPointProducts.com. This article was reviewed by Timothy Taylor, MD, CMTPT, director of Pain Relief Home, a practice specializing in the treatment of myofascial pain located in Richmond, VA (www.PainReliefHome.net).