Tender Point Or Myofascial Trigger Point?
A promising new area of research into mysterious fibromyalgia is generating excitement among experts in the field. Two studies funded by the American Fibromyalgia Syndrome Association (AFSA) are looking into the relationship between fibromyalgia pain points and myofascial trigger points (MTPs). Current fibromyalgia philosophy holds that the tender points of fibromyalgia are unrelated to MTPs because only MTPs cause referred pain. However, according to Robert Bennett, M.D., of Oregon Health Sciences University in Portland, “The artificial distinction between tender points and trigger points could be eliminated and the current locations could be redefined as myofascial trigger points on the basis of clinical and electromyographic findings.”
Electromyography (EMG) employs miniscule needle probes that, when inserted into muscles, can record electrical activity in specific areas. When an EMG probe enters the middle of a knot caused by a MTP, it picks up electrical activity that can pinpoint the exact location of the trigger point. If the electrical activity generated by a tender spot indicates that there is referred pain, located elsewhere than at the area of testing, the tender spot can be redefined as a tender point that is also an MTP.
The question you may be asking is whether it matters that some or perhaps all of the 18 tender points used to identify fibromyalgia are really MTPs? Indeed, it matters a great deal and may end up affecting the way fibromyalgia is diagnosed and treated. It is imperative that the matter be settled: are MTPs the main source of the tender points that cause the pain and dysfunction of FMS?
Much is known about the chemical composition of the active MTP, the center of which contains a large amount of bad-boy chemicals including norepinephrine, tumor necrosis factor, calcitonin gene-related peptide, substance "P," and bradykinin. Even those MTPs which are latent and do not cause pain when a person is unmoving or at rest are known to contain increased concentrations of these dire substances. Everyone has such latent MTPs. They exist in tight muscles.
When one overworks a tight muscle, an MTP is set off. The effect of this latent MTP is to serve as a warning and to inhibit muscle movement so that one is forced to compensate by substituting a different muscle. Most people don't realize they have a latent MTP until pressure is applied to the spot. The way such an MTP differs from a tender spot such as is used as a factor in diagnosing FMS is that the knot can be treated so that the accompanying chemicals are dissipated, along with all the associated symptoms of muscle tightness, weakness, and pain.
If it were to be found that the tender points of fibromyalgia were really MTPs, the treatment for FMS would undergo a radical change. The diagnostic procedures for identifying FMS would need to be reevaluated and overhauled. David Simons, M.D., commented, “The lack of consideration of MTPs in FMS research has resulted in a whole body of literature highly contaminated by unrecognized MTP effects that renders it not only incomplete but also sometimes seriously misleading. This stems from the early erroneous report—by a rheumatologist unskilled at finding MTPs—that MTPs are rarely found in patients with FMS, which has become the uncontested truth to many rheumatologists. Unfortunately, to date, there has been no competent study published to correct this misinformation.”