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Trigger Point Low Level Laser Therapy

A case study documents a trapezius trigger point eradication after three sessions of far infrared laser irradiation and confirms with anatomic "before-and-after" diagnostic ultra-sonographs.
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The last two decades of medicine has seen the emergence of a group of conditions presumably thought to be primarily of soft tissue origin and affecting a growing number of people. Of importance has been the relative paucity in hard diagnostic criteria that practitioners require to identify these disorders. The terms fibrositis, myofascitis, myalgic syndrome, and fibromyositis syndrome have all attempted to take their turn as consensus diagnostic labels used to describe the characteristic focal pain and tenderness in soft tissues. The taxonomy has been forced to change over time to accommodate the growing empirical evidence, as well as the continued clinical disparity that surrounded these diagnostic labels. Some authors have even termed them “functional syndromes” due, in part, to their alleged lack of reliable objective clinical markers including lab analysis and/or imaging methods.

A common problem in trigger point studies to date has been that the study populations used may not always have been adequately described by the investigators. The reader is not always confident that they are treating the problem of a TP versus other similar, yet different, clinical conditions that manifest with localized soft tissue pain and tenderness. This is a problem that other authors have also alluded to.1 There have been numerous treatment regimens endorsed for the treatment of trigger points. Included in this list are injections, acupuncture, continuous ultrasound, myofascial release, massage therapy, positional releases, pharmacologic treatments, spray and stretch, TENS, and most recently, laser therapy.3

Trigger Point Pathophysiology

In a previous Practical Pain Management article, Dunteman1 provided a detailed explanation on the distinctive features between fibromyalgia and myofascial syndromes. Using this description as a premise, one can understand that the trigger point is the defining clinical feature of myofascial pain syndromes. Simons and Travell2 have pioneered the original investigations of trigger points and provided us with an extensive explanation of TP pathophysiology and behavior. There are major and minor diagnostic criteria available to help guide clinicians in the proper identification of TPs since soft tissue pain and tenderness alone are common manifestations of many other pathologies.

The absence of research evidence validating a set of reliable diagnostic radiologic markers however, continues to relegate the existence of TPs, and perhaps myofascial syndromes in general, to being recognized by some, but rejected by others. The axiom “we only diagnose what we recognize” may well be modified to include “and we only recognize what we deem has good evidence.” Some clinicians/payors will continue to hold a higher evidentiary standard requirement to TPs before their existence is fully accepted. The application of criteria devoid of any quantitative element continues to be a barrier for more complete acceptance in all sectors of the clinical/legal and payor communities acknowledging TPs as the primary pathological entity in the myofascial syndromes.

The following case report describes what is felt to be not only an effective method of TP treatment (cold laser), but also an effective method of TP corroboration that goes beyond a practitioner’s palpatory prowess. A safe and reliable method to radiologically verify trigger points should prove more convincing to skeptical practitioners, and may add even greater diagnostic accuracy to those practitioners already familiar with TP phenomenon via palpation.

Case Description

The patient was a 42-year-old male who complained of pain and dysfunction in the right mid trapezius muscle after having sustained a strain to the area a few months past, from a work-related exertional effort. A typical activity that can lead to such an injury might be related to a shoulder shrug action under load, such as when attempting to lift a heavy weight from waist to shoulder levels. This was the case with the patient. The patient presented with generalized right shoulder and neck pain but predominantly in the trapezius muscle. Palpation of the specific muscle bundle was exquisitely tender with increasing pressure causing pain radiation into the arm and scapula, as well as cephalad to the para-cervical musculature. The pain increased during both stretch and tension application to the trapezius — a method described originally by Cyriax and known as selective tissue tension testing. A jump sign was also elicited with localized pressure application to the mid trapezius. A palpable nodule was identified in the right trapezius which also correlated with the most tender area of the muscle. The neck and entire right extremity were cleared for any referred pain phenomenon. This patient was otherwise healthy with no other medical problems and was not taking any medication.

Trigger Point Localization and Verification

The initial examination used the traditional method of trigger point localization described by many authors in the past and based largely on patient complaints, pain description and application of the major and minor trigger point criteria as described by Simons and Travell.2 The clinical characteristics included: pain elicited on passive or active stretch of the muscle most involved leading to restricted joint AROM or muscle excursion itself; muscular contraction leading to pain; tenderness and dysesthesias referred in commonly defined zones; palpatory pressure elicits the “jump sign” leading to wincing, withdrawing, or vocalizing; and local fasciculation or twitching during firm pressure.

The author confirmed this palpatory finding with diagnostic ultra-sonography (DUS) a technique that is evolving rapidly as a first line soft tissue screening test.4 The author used a basic Hitachi 2-D ultrasound unit utilizing a moderately high frequency transducer (7.5 MHz) without added high resolution capabilities, doppler, or harmonic imaging option. The sonographic “signature” of a trigger point is neither obvious nor identified with absolute certainty in all cases. Unlike a tendon or muscle tear, both of which are relatively easier to detect ultrasonically, a subtle lesion such as a TP is somewhat more challenging. In this case the scan was confined to the most tender area of the involved trapezius muscle.

Last updated on: January 5, 2012
First published on: November 1, 2004