Myofascial Pain Syndrome: Trigger Points

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Nov 22, 2011 - Safety and effectiveness of an internal pelvic myo- fascial trigger point wand for urologic chronic pelvic pain syndrome. Clin J Pain 27(9): ...
Journal of Musculoskeletal Pain, Vol. 20(1), 2012 © 2012 Informa Healthcare USA, Inc. ISSN: 1058-2452 print / 1540-7012 online DOI: 10.3109/10582452.2011.644395

LITERATURE REVIEW

Myofascial Pain Syndrome: Trigger Points Jan Dommerholt, PT, DPT, MPS1 and Carel Bron, PT, PhD2

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Bethesda Physiocare/Myopain Seminars, Bethesda, MD, USA, 2Scientific Institute for Quality of Healthcare, Radboud University Nijmegen Medical Centre, The Netherlands; Private Practice for Physical Therapy for Neck, Shoulder and Upper Extremity Disorders, Groningen, The Netherlands

INTRODUCTION

As many LTRs were elicited as possible, after which a 0.5 percent lidocaine solution was injected to reduce post-needling soreness. One observer identified LTRs by visual inspection, while a second observer observed LTRs on the sonography monitor. The effectiveness of the injections was measured with pre- and post-visual analog scales for pain. LTRs in the upper trapezius were observed by both observers. In the low back muscles, 196 LTRs were observed only via sonography from a sample of over 1000 injections. The LTRs were more commonly observed with sonography in the deeper sections of the low back muscles than in the upper trapezius and in the more superficial parts of the low back muscles. Reduction of pain was significantly greater following LTRs.

In 2004, Dr David Simons invited me [J.D.] to assist him in the preparation of this review column. Eight years later, I am pleased to welcome Carel Bron, PT, PhD, as co-author of this review article. Dr Bron completed his doctorate at the Radboud University Nijmegen Medical Centre, Scientific Institute for Quality of Healthcare [IQ healthcare] in the Netherlands. In his dissertation, he discussed the role of trigger points [TrPs] in shoulder dysfunction (1,2). Dr Bron’s in-depth knowledge of the TrP literature and vast clinical experience will be obvious to the readers and an asset to the Journal. Each article review will indicate whether it is prepared by Dommerholt [J.D.] or Bron [C.B.]. RESEARCH STUDIES

COMMENTS It is initially a bit confusing that the authors reported that ultrasound identified LTRs better in deeper muscles. In the discussion section of the papers, however, they stated that this was in comparison to visual inspection, a detail they did not mention in the results section. From a clinical perspective, this reviewer does not believe that ultrasound guidance is critical for experienced clinicians, but ultrasound may be useful during the training phase when learning how to perform TrP injections and possibly for needling deeper muscles. This paper does confirm the importance of eliciting LTRs. Apparently, the authors were not familiar with an older paper by Gerwin and Duranleau in which they explored the use of sonography to detect LTRs (3) [J.D.].

Rha D-W, Shin JC, Kim Y-K, Jung JH, Kim YU, Lee SC: Detecting local twitch responses of myofascial trigger points in the lower-back muscles using ultrasonography. Arch Phys Med Rehabil 2(10): 1576–1580, 2011. SUMMARY In this study of 41 patients with trigger points [TrPs] in the upper trapezius and 62 patients with TrPs in the lumbar erector spinae or quadratus lumborum muscles, the researchers attempted to detect local twitch responses [LTRs] during TrP injections and assess their importance under ultrasound guidance. A 25-gauge 3.8 or 6 cm needle was used for the upper trapezius and low back muscles, respectively.

Address correspondence to: Dr Jan Dommerholt, Bethesda Physiocare/Myopain Seminars, 7830 Old Georgetown Road, Suite C-15, Bethesda, MD 20814-2440, USA [Email: [email protected]] Submitted: November 22, 2011; Revisions Accepted: November 22, 2011

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Myofascial Pain Syndrome

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Hayashi K, Ozaki N, Kawakita K, Itoh K, Mizumura K, Furukawa K, Yasui M, Hori K, Yi SQ, Yamaguchi T, Sugiura Y: Involvement of NGF in the rat model of persistent muscle pain associated with taut band. J Pain 12(10): 1059– 1068, 2011. SUMMARY This Japanese study explored the role of nerve growth factor [NGF] in the formation of taut bands in myofascial pain. The authors reviewed the involvement of NGF in sensitization of several muscle nociceptors, including vanilloid receptors and purinergic receptors, and upregulation of acid-sensing ion channel 3, which are thought to be involved in the etiology and pathophysiology of trigger points [TrPs] (4,5). Simultaneously, NGF is synthesized in the skeletal muscle and contributes to muscle regeneration following injury. The researchers attempted to create a model of persistent muscle pain with taut bands. Twelve anesthesized rats received electrically induced eccentric contractions of the gastrocnemius muscle [300 procedures per day for two weeks] sufficient to create delayed onset of muscle soreness. Mechanical hyperalgesia was assessed using standardized methods. Taut bands were manually assessed followed by muscle hardness measures. All animals in the study group presented with taut bands compared with none in the control group. Next, the gastrocnemius muscles were dissected out and analyzed for the presence of NGF content. The evaluator was blinded to the treatment of the animals. The study included several other analytic methods and analyses. The authors managed to develop a model of persistent muscle pain associated with taut bands. They found evidence of muscle hyperalgesia and histological changes, which were most consistent with TrPs observed in overtrained athletes. They concluded that NGF expressed in regenerating muscle cells might enhance motor end-plate activity through upregulation of calcitonin-gene-related peptide at the motor nerve fiber terminals and contribute to the development of taut band in which TrPs are located. In addition, considering its role in the peripheral sensitization, NGF produced in regenerating muscle cells might be involved in the mechanisms of TrP formation. The authors concluded that NGF expressed in regenerating muscle cells may play an important role in persistent mechanical muscle hyperalgesia relevant to the pathogenesis of myofascial pain.

COMMENTS This study contributes significantly to our understanding of the potential role of NGF in mechanical hyperalgesia associated with TrPs. As has been suggested previously, eccentric loading appear to be an important aspect of TrP formation (6). This study highlighted one component of the original concepts of TrP formation and the findings further expand the integrated TrP hypothesis [J.D.]. CLINICAL STUDIES Unalan H, Majlesi J, Aydin FY, Palamar D: Comparison of high-power pain threshold ultrasound therapy with local injection in the treatment of active myofascial trigger points of the upper trapezius muscle. Arch Phys Med Rehabil 92(4): 657– 662, 2011. SUMMARY Of an initial sample of 197 patients with acute [duration four weeks or less] neck pain, 49 [24 percent] subjects with at least one acute trigger point [TrP] in the trapezius muscle at one side, were randomly assigned to either a treatment group [n = 25] or a control group [n = 24]. Patients with signs or symptoms of cervical radiculopathy or severe disease were excluded. The experimental group was treated with high-power pain threshold ultrasound for one or two sessions. High-power pain threshold ultrasound was applied in a continuous stationary mode with the probe directly placed over the TrP. The intensity was increased gradually to the maximum level of pain the patient could tolerate. The probe was left in place for three to four seconds, after which the intensity was reduced to 50 percent for another 15 seconds. This procedure was repeated three times. The control group received a single 0.5 percent lidocaine injection according to the technique described by Simons et al. (7). Outcome measures were the visual analog scale [VAS], active range of motion in lateral bending, and the number of treatments sessions. Any side effects were reported. Outcome measures were assessed immediately following the treatment. Side effects were recorded at one and four weeks post-treatment. Patients in both groups improved immediately post-treatment on the VAS with no statistical significant difference between groups. The active side bending of the neck improved in the intervention group −5.3 [95 percent confidence interval [95% CI] −7.7 to −2.9] and in the control group −3.6 [95% CI −5.2 to −2.0]. The mean number of sessions was

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lower in the control group than in the intervention group [mean difference −0.5; 95% CI −0.81 to −0.22]. There was only one patient in the intervention group, who reported erythema for 3 days. The authors conclude that both interventions are equally effective and therefore can be used in the treatment of patients with acute TrPs. COMMENTS Both interventions have a significant and clinically relevant post-treatment decrease in VAS scores. The differences between the groups were not statistically significant. The authors did not report a sample size calculation, but it is conceivable that a larger study sample could have given a statistical significant difference between the interventions. The long-term effects of either treatment remain unclear [C.B.]. Anderson R, Wise D, Sawyer T, Nathanson BH: Safety and effectiveness of an internal pelvic myofascial trigger point wand for urologic chronic pelvic pain syndrome. Clin J Pain 27(9): 764–768, 2011. SUMMARY To facilitate self-treatments for their patients with chronic pelvic pain, Anderson and colleagues developed a specially curved wand to locate and treat internal trigger points [TrPs]. The wand features a build-in algometer to guide the appropriate pressure. Patients are instructed to use the wand several times per week after they have been educated and evaluated. In this prospective open-label study, the authors examined the safety and efficacy of the device. One hundred and thirteen patients [106 males] completed a six-month study protocol with outcome measures taken at one and six months. Patients recorded adverse effects and rated their pain perception of TrPs before and after use of the wand on a 10-point visual analog scale. The authors concluded that the use of the wand as part of a multimodal treatment approach was effective, as 93 percent of patients reported a moderate-to-marked satisfaction with the wand and a greater than a 25 percent perceived reduction in TrP sensitivity in 77 percent of patients after six months. COMMENTS Other than the excellent results reported with the use of the wand, this paper brings up other questions. If the self-treatments are so effective in the pelvic floor region, it seems reasonable to explore whether

similar self-treatment regimens should be considered in the treatment of TrPs in other regions of the body. Part of the multi-modal treatment program, patients are examined and treated by a skilled physical therapist, but following discharge from the intensive treatment program, many patients continue with self-treatments at home. While there are many pressure devices on the market, few, if any, include an algometer. It is not clear from the paper whether the authors assessed whether patients considered the algometer measurements during their selftreatment. Although the questionnaire did include questions related to pressure measurements of the wand, the authors did not report the replies to these questions [J.D.]. Ōzkan F, Çakir Ōzkan N, Erkorkmaz U: Trigger point injection therapy in the management of myofascial temporomandibular pain. Agˇ ri 23(3): 119–125, 2011. SUMMARY Fifty subjects with temporomandibular myofascial pain were randomly assigned to one of two groups. All subjects were treated with a stabilization splint, but the patients in the second group also received trigger point [TrP] injections of 0.5 ml lidocaine + 0.5 ml saline into the masseter [22 injections], temporalis [13 injections], and lateral pterygoid muscles [20 injections]. Outcome measures, consisting of a visual analog scale for pain, mandibular incisal opening, were taken two, four, and 12 weeks following completion of the therapy. Both groups improved for all outcome measures, but the patients in group 2 experienced a significantly greater reduction in pain and more improvement in their temporomandibular disorder symptoms. The authors speculated that especially referred pain was diminished. In conclusion, the combination of splint therapy and TrP injections was more effective than splint therapy alone. COMMENTS It is interesting that the authors used the Research Diagnostic Criteria for temporomandibular dysfunction, but at the same time identified TrPs, which are not considered in these criteria. It is not clear what criteria they used to identify TrPs other than the area of maximum tenderness. The study lacks a control group without treatment. It would be interesting to determine the effectiveness of TrP therapy without splint therapy. Overall, this paper does support the combination of splint therapy and TrP injections [J.D.].

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Myofascial Pain Syndrome

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Chen CK, Nizar AJ: Myofascial pain syndrome in chronic back pain patients. Korean J Pain 24(2): 100–104, 2011. SUMMARY One hundred and twenty-six patients with chronic back pain participated in this prospective study of the prevalence of myofascial pain syndrome [MPS]. Trigger points [TrPs] were identified using a standardized digital pressure of 2 kg. Recognition of pain was used as one of the criteria for the MPS diagnosis. To elicit referred pain, the researchers increased the pressure to 3–4 kg/cm2. Other outcome measures included subjective complaints of pain using a visual analog scale [VAS] and the Modified Oswestry Disability Score. Following the assessment, all subjects received physical therapy, oral medication [mostly nonsteroidal anti-inflammatory drugs], exercise, and when their initial pain score was in excess of a 7 on the VAS, TrP injection were administered. Eighty of the 126 subjects met the criteria for MPS, which equates to a prevalence of 63.5 percent. The authors mentioned that 81.2 percent of the patients presented with secondary MPS. Most common muscles with TrPs were the trapezius [90.9 percent], followed by the supraspinatus and rhomboids [each 45.5 percent], and sternocleidomastoid and scalene muscles [each 18.2 percent]. In the lower half of the body, the most common muscles included the piriformis [63.8 percent], lumbar paravertebral muscles [37.9 percent], gluteus medius [12.1 percent], gluteus minimus [10.3 percent], and the quadratus lumborum muscle [6.9 percent]. Females were more likely to have MPS with an odds ratio of 2.4. The authors reported that the multimodal treatment improved the VAS and Oswestry scores. Most subjects required only one or two injections. Four subjects did not improve and were offered injections with botulinum toxin. COMMENTS While this is an interesting clinical study supporting the notion that TrPs are commonly present in chronic back pain, there are several remaining questions. The authors stated that over 80 percent of the subjects had secondary MPS without defining how they derived that percentage. How did the authors determine that TrPs were secondary to other co-morbid findings? The authors did not report what injectate was used or which muscles were injected. When they resorted to injections with botulinum toxin, they did not provide any further details either.

They state that this study provides evidence that a multi-disciplinary approach is required, but that was not the main focus of the study. There was no control group and therefore the conclusion is not supported by the data. The authors apparently equated physical therapy with applications of heat and ultrasound, which is a common error made by nonphysical therapists. Heat and ultrasound are just modalities used by many disciplines, but these modalities do not define any discipline including physical therapy. Exercise regimens were not described other than in generic terms of stretching and strengthening, making it impossible to replicate this study. It is surprising that the researchers found that only 6.9 percent of subjects had TrPs in the quadratus lumborum muscle. Based on empirical data, it appears that nearly every patient with chronic low back pain has clinicially relevant TrPs in this muscle [J.D.]. REVIEWS Annaswamy TM, De Luigi AJ, Bryan J. O’Neill BJ, Keole N, Berbrayer D: Emerging concepts in the treatment of myofascial pain: a review of medications, modalities, and needle-based interventions. PMR 3:940–961, 2011. SUMMARY This review article focused on emerging advances in the treatment of persons with myofascial pain syndrome [MPS] not including manual therapies. The authors searched several databases from 2000 to 2010 and assigned levels of evidence to each paper using Wright’s criteria (8). Studies with high levels of evidence were identified with broad recommendations for medications, modalities, needle-based interventions, and injectable toxins. Regarding medications, the authors concluded that there is insufficient evidence for the use of cyclobenzaprine, tizanidine, ibuprofen, diclofenac, nortriptyline, acetylsalicylic acid, acetaminophen, naproxen, celecoxib, gabapentin, pregabalin, tiagabine, -tryptophan, ketamine, tramadol, dihydrocodeine, and memantine, topical thiocolchicoside ointment, monoamine oxidase inhibitors such as moclobemide, selective serotonin reuptake inhibitors such as fluoxetine and citalopram, and serotonin norepinephrine reuptake inhibitors such as duloxetine, venlafaxine, and milnacipran. Diazepam and alprazolam were found to be ineffective by themselves, but potentially beneficial in combination with other medications. There was strong support for the use of clonazepam and limited support for topical diclofenac patch and solution and amitiptyline in

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certain conditions. Potentially promising medications included tropisetron, sumatriptan, topical lidocaine patches, and topical methyl salicylate and menthol patches. Several modalities could be used in the management of MPS, but the evidence is not overwhelming. Electrotherapy has limited support, but ultrasound may be a useful adjunctive therapy. Laser was considered an emerging therapy, while there was insufficient evidence for magnetic stimulation. The authors found good evidence for TrP injections and superficial and deep dry needling. Acupuncture-based dry needling was difficult to evaluate due to small sample sizes and methodological issues. Botulinum toxin appeared to be a promising intervention, but research findings were conflicting. COMMENTS This comprehensive meta-review offers new insights, especially regarding the [lack of] efficacy of multiple medications commonly used in the treatment of patients with TrPs. According to this extensive literature review, few medications have even reasonable scientific support, which may partially be due to the limited understanding of the underlying mechanisms of myofascial pain and the lack of evidence-based diagnostic criteria. The effectiveness of various modalities was previously reviewed by Rickards in 2006 (9) with similar conclusions. [J.D.] Mense S: Unterschiede zwischen myofazialen Triggerpunkten und “tender points” [in German: Differences between myofascial trigger points and tender points]. Schmerz 25(1): 93–103, 2011. SUMMARY In this review paper, the characteristics of trigger points [TrPs] and the characteristics of tender points [TePs] in fibromyalgia syndrome [FMS] patients are presented and the differences between those two entities are emphasized. According to Mense, TrPs are palpable nodules in muscles, especially found in the muscle belly, while TePs are points mostly found at muscle attachments, which are painful with compression. TePs are always distributed throughout the body and tend to be more symmetrical, while TrPs can be found in one single muscle or body region. Allodynia and hyperalgesia are limited to the region of the TrPs but in patients with widespread pain this is also found in tissue outside the TePs. Local twitch responses, which are typically for TrPs, do not occur in TePs. Biopsies of TrPs reveal pathological sarcomere contractures, while in TePs there are no

histopathological findings. The ragged red fibers found in muscles of FMS patients are not specific for this population, as they are also seen in the elderly or with work-related myalgia. Trigger points are likely to be caused by peripheral sensitization, whereas TePs are more likely to be the result of central central sensitization. According to the author, the many differences between TrPs and TePs speak against a common etiology and pathophysiology. COMMENTS Several studies have confirmed that the local and referred pain elicited from active TrPs fully reproduced the overall spontaneous FMS pain pattern (10,11). Generalized mechanical hyperalgesia in FMS is related to a greater number of active TrPs and peripheral inputs from these TrPs may drive central sensitization. Affaitati et al. (12) suggested that reducing peripheral nociceptive input from TrPs is effective in decreasing widespread pain in FMS patients. There may be a significant overlap in symptoms between patients with FMS and patients with widespread TrPs in spite of Mense’s assumption that TrPs and TePs would be so different. Nevertheless, we agree with the author that not all painful spots in the body are TrPs [C.B.]. Díaz-Mohedo E, Baron-López FJ, Pineda-Galán C: Consideración etiológica, diagnóstica y terapéutica del componente miofascial en el dolor pélvico crónico [in Spanish: Etiological, diagnostic and therapeutic consideration of the myofascial component in chronic pelvic pain]. Actas urologicas espanolas 35(10): 610–614, 2011. SUMMARY This Spanish study explored whether there is sufficient scientific evidence for a potential role of trigger points [TrPs] in pelvic pain syndromes. The authors examined reviews, randomized controlled clinical studies, cohort studies, and case studies from the PubMed and Cochrane Library databases from 2000 to 2009. They concluded that there is ample evidence that myofascial pain plays a significant role in chronic pelvic pain syndromes. When TrPs are not considered, pelvic pain syndromes may not resolve completely. COMMENTS This brief report in a Spanish urology journal emphasizes that TrPs are important in the evaluation and management of patients suffering from chronic pelvic pain syndromes [J.D.].

Myofascial Pain Syndrome CASE REPORTS

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Janis JE, Dhanik A, Howard JH: Validation of the peripheral trigger point theory of migraine headaches: single-surgeon experience using botulinum toxin and surgical decompression. Plast Reconstr Surg 128(1): 123–131, 2011. SUMMARY In this multiple case study, 24 patients [23 female, one male] underwent a combined injection protocol with botulinum toxin type A, followed by surgical decompression of so-called trigger points [TrPs]. These TrPs were described as parts of muscles surrounding nerve tissue causing nerve entrapment, such as the semispinalis muscle surrounding the greater occipital nerve, the corrugator supercilii muscles surrounding the supraorbital nerves and the supratrochlear nerves [bilateral], and the temporalis muscles surrounding the zygomaticotemporal nerves [also bilateral]. If patients reported more than 50 percent of improvement in migraine headache frequency, duration or severity after the botulinum toxin injection, the site was confirmed to be a TrP. At this point, residual migraine headaches were treated with additional injections at other potential sites. Once this protocol was completed, surgical decompression of the TrPs was offered to patients who showed significant improvement with injection therapy. All patients reported improvement [six elimination of migraine headache, 17 significant improvement, and one modest improvement] after injection therapy. Two patients were completely free of migraine headaches after surgery, 17 patients showed significant improvement, and five failed surgery [mean follow-up was 661 days, approximately 1.8 years, range 157 to 1615 days]. Complications after the injections were migraine headache attack, neck soreness or weakness, diplopia, ptosis and mild mastication weakness. Complications after surgery were hematoma in the occipital region. COMMENTS Although the paper suggests that this is a report on TrPs, the author did not define TrPs according to the definition of Simons, Travell, and Simons. Instead, he seemed to describe nerve entrapment sites. It is not clear why he uses TrP terminology to describe an entirely different phenomenon. Surgical removal of muscle tissue appears to be an effective treatment; however, the results should be interpreted carefully. The surgeon who performed the treatment was also responsible for the assessments and the statistical analysis. As this is an invasive and likely

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expensive intervention, future studies should compare this intervention with non-invasive and less expensive options [C.B.]. Shin SJ, Kang SS: Myositis ossificans of the elbow after a trigger point injection. Clinics in orthopedic surgery 3(1): 81–85, 2011. SUMMARY Serious complications of trigger points [TrP] injections are rare. In this Korean case report, the authors presented a 31-year-old male patient with mild pain at his left elbow for three weeks. Onset of pain coincided with throwing and catching a ball. He was treated with a TrP injection with 0.5 ml of 2 percent lidocaine and 1.5 ml of normal saline at another clinic. When the patient presented two weeks later, he had swelling, redness, and pain, which did not respond to nonsteroidal anti-inflammatory drugs and physical therapy. Two weeks later, he was referred to the authors who noted restricted range of motion, an increased erythocyte sediment rate, swelling noted with a plain radiograph, and a “suspicious lesion” between the insertion of the brachialis and supinator muscle. A deep soft tissue infection was suspected and the patient was started on intravenous antibiotics. In spite of the treatment, the symptoms worsened and six weeks after the TrP injection, elbow range of motion was severely restricted, and a palpable mass appeared. Ultrasonography suggested a possible calcification. Computed tomography confirmed the diagnosis of myositis ossificans, which was surgically excised at eight weeks after the TrP injection. Histological analysis revealed extensive osteoid formation. Two months following the excision, full range of motion was restored. Three years later, the patient had no recurrence and continued to have full range of motion. In the discussion section, the authors reviewed the scientific literature of the development of myositis ossificans. They identified just a few papers describing myositis following injections. They speculated that the patient may have had hemorrhage or hematoma caused by the injection with lidocaine, which possibly caused a release of calcium from the muscle, vascular stasis, tissue hypoxia, and eventually the myositis ossificans. They suggested that a TrP injection would be inappropriate for lateral epicondylitis. COMMENTS As the authors mentioned, serious complications of TrP injections are indeed very rare. This report is the first paper to describe the development of myositis ossificans following a TrP injection with lidocaine

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and as such, the case report is an important contribution to the TrP literature. The authors suggested that TrP injections should not be used with lateral epicondylitis, but frequently lateral epicondylalgia, which is the preferred term, may indeed be due to TrPs in the elbow muscles. In those cases, TrP injections would be justified as part of a medical management strategy [J.D.]. Hidalgo-Lozano A, Fernández-de-Las-Peňas C, Díaz-Rodríguez L, González-Iglesias J, PalaciosCeňa D, Arroyo-Morales M: Changes in pain and pressure pain sensitivity after manual treatment of active trigger points in patients with unilateral shoulder impingement: A case series. J Bodyw Mov Ther 15(4): 399–404, 2011. SUMMARY Twelve consecutive patients [seven men and five women, aged 20–38] who were diagnosed with strictly unilateral subacromial impingement syndrome stage I [according to Neer] were included in this study. Inclusion criteria were unilateral shoulder complaints for at least three months with a pain intensity of at least 4 on an 11-point numerical pain rating scale during arm elevation and a positive test result on the Neer and Hawkins–Kennedy tests. Exclusion criteria were bilateral symptoms, younger than 18 or older than 65 years of age, history of shoulder fractures or dislocations, cervical radiculopathy, neck or shoulder surgery, fibromyalgia syndrome, previous steroid injections, or any physical intervention in the neck–shoulder area in the previous year. Outcome measures were the visual analogue scale [VAS] and pressure pain threshold [PPT] of the levator scapulae, supraspinatus, infraspinatus, and tibialis anterior muscles, which were taken at baseline, immediately post-intervention after two weeks, and at a four-week follow-up. All patients were treated by the same clinician with six years of clinical experience in the management of shoulder disorders and received four treatments [two treatment sessions per week]. Prior to the treatment, the patients were examined for TrPs in the levator scapulae, supraspinatus, infraspinatus, subscapularis, and pectoralis major muscles according the guidelines of Simons et al. (7) by another clinician with five years of experience in TrP management. Manual treatment consisted of TrP pressure release over each active TrP followed by longitudinal stroking massage over the affected muscles. There was a significant reduction in pain after four weeks [mean difference VAS between baseline and follow-up 1.3 [95 percent confidence interval [95% CI] 0.9–2.3] [mean VAS at

baseline was 5.1 [95% CI 3.9–6.4]. Post-intervention outcome was not presented. The effect size for pain was large [Cohen’s d > 1]. Pressure pain threshold scores were significantly higher immediately postintervention and at four weeks after discharge. The authors concluded that this case series suggests that manual treatment of active TrPs may reduce spontaneous pain and increase PPT in patients with shoulder impingement. COMMENTS The results of this uncontrolled study with small sample size are in accordance of other larger randomized controlled studies of manual TrP therapy in patients with shoulder pain (1,13). Manual treatment of TrPs in shoulder muscles of patients with chronic pain is a viable treatment option [C.B.]. Lawson GE, Hung LY, Ko GD, Laframboise MA: A case of pseudo–angina pectoris from a pectoralis minor trigger point caused by cross-country skiing. J Chiropractic Med 10: 173–178, 2011. SUMMARY A 58-year-old male patient presented with left-sided shoulder pain with radiation into the neck and medial aspect of the arm, which was aggravated by cross-country skiing, which the patient had started recently. The arm pain reached an intensity of 8/10 on a numeric pain scale. He also experienced tachycardia, fatigue, and exhaustion. He had been diagnosed with anterior chest pain with chest wall origin by a previous physician. The patient had lateral chest pain with palpation of the pectoralis minor and major muscles, which also reproduced his medial arm pain. The patient had mild forward head posture and normal cervical range of motion, although rotation and extension caused mild bilateral pain. Motion testing showed restrictions in the lower cervical and upper thoracic spine. He was diagnosed with active trigger points in the left pectoralis minor and major muscles. Treatment with the Graston technique with gentle stretches reduced the pain and referred pain patterns in just four treatment sessions. The patient was able to continue cross-country skiing with advice for proper technique and post-skiing stretches. In the discussion section, the authors reviewed the biomechanics of cross-country skiing, based on which they modified the ski strokes. COMMENTS This article, published in a chiropractic journal, is an excellent case report emphasizing the importance of

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considering non-cardiac causes of chest pain. Trigger points in the pectoralis minor were found to be responsible for the referred pain into the chest and arm. The authors showed that considering the etiology of the pain complaint is critical in providing optimal patient care. Their brief review of the biomechanics of cross-country skiing provides the rationale for the treatment and technique corrections [J.D.]. Min SH, Chang SH, Jeon SK, Yoon SZ, Park JY, Shin HW: Posterior auricular pain caused by the trigger points in the sternocleidomastoid muscle aggravated by psychological factors – a case report. Korean J Anesthesiol 59(Suppl): S229– S232, 2010. SUMMARY In this case report from Korea, a 50-year-old taxi driver presented with right posterior auricular pain. The pain started four days earlier when he turned his head to the right to give the taxi fare change to a passenger. He rated the pain as 5–8 on a 10-point visual analog scale. He was evaluated by an otologist and dentist who found no abnormalities. His past medical history revealed a similar pain complaint which was diagnosed as a glossopharyngeal neuralgia. A cervical spine computed tomography and magnetic resonance imaging were normal. This time he was diagnosed with a trigger point [TrP] in the right sternocleidomastoid muscle and limited right rotation. He was treated with a 0.25 percent lidocaine TrP injection which reduced the pain to a level 2 to 3/10, but the pain returned just two hours later. He received more TrP injections with 0.125 percent bupivacaine and oral intake of 1300 mg acetamiophen and 5 mg diazepam three times daily, but the pain did not resolve. He had an accessory nerve block, superficial cervical nerve plexus block, and transcutaneous nerve stimulation, which only provided temporary relief. Upon further investigation, the patient shared that he was involved in a very stressful family situation. Although he initially declined psychological treatment, once he consented, the pain steadily decreased following psychological counseling. Minor residual pain was resolved with a TrP injection and a nerve block.

COMMENTS This is a good illustration that psychological factors can contribute to and maintain pain associated with TrPs. The authors reported that initially the patient rejected psychological counseling as he interpreted the referral as a sign that his doctor thought that he would have a mental disorder. Although this is a common response of patients, the authors emphasized that the experience of pain is often associated with psychological factors [J.D.]. REFERENCES 1 Bron C, de Gast A, Dommerholt J, Stegenga B, Wensing M, Oostendorp RAB: Treatment of myofascial trigger points in patients with chronic shoulder pain; a randomized controlled trial BMC Med 9: 8, 2011. 2 Bron C, Dommerholt J, Stegenga B, Wensing M,Oostendorp RA: High prevalence of shoulder girdle muscles with myofascial trigger points in patients with shoulder pain. BMC Musculoskelet Disord 12(1): 139, 2011. 3 Gerwin RD, Duranleau D: Ultrasound identification of the myofascial trigger point. Muscle Nerve 20(6): 767–768, 1997. 4 Mense S: Algesic agents exciting muscle nociceptors. Exp Brain Res 196(1): 89–100, 2009. 5 Sluka KA, Price MP, Breese NM, Stucky CL, Wemmie JA, Welsh MJ: Chronic hyperalgesia induced by repeated acid injections in muscle is abolished by the loss of ASIC3, but not ASIC1. Pain 106(3): 229–239, 2003. 6 Gerwin RD, Dommerholt J, Shah JP: An expansion of Simons’ integrated hypothesis of trigger point formation. Curr Pain Headache Rep 8(6): 468–475, 2004. 7 Simons DG, Travell JG, Simons LS: Travell and Simons’ Myofascial Pain and Dysfunction; the Trigger Point Manual. 2nd Edition, Vol. 1. Williams & Wilkins, Baltimore, 1999. 8 Wright JG: A practical guide to assigning levels of evidence. J. Bone Joint Surg. Am. 89(5): 1128–1130, 2007. 9 Rickards LD: The effectiveness of non-invasive treatments for active myofascial trigger point pain: A systematic review of the literature. Int J Osteopathic Med 9(4): 120–136, 2006. 10 Alonso-Blanco C, Fernandez-de-Las-Penas C, Morales-Cabezas M, Zarco-Moreno P, Ge HY, Florez-Garcia M: Multiple active myofascial trigger points reproduce the overall spontaneous pain pattern in women with fibromyalgia and are related to widespread mechanical hypersensitivity. Clin J Pain, 2011. 11 Ge HY, Nie H, Madeleine P, Danneskiold-Samsoe B, GravenNielsen T, Arendt-Nielsen L: Contribution of the local and referred pain from active myofascial trigger points in fibromyalgia syndrome. Pain 147(1–3): 233–240, 2009. 12 Affaitati G, Costantini R, Fabrizio A, Lapenna D, Tafuri E, Giamberardino MA: Effects of treatment of peripheral pain generators in fibromyalgia patients. Eur J Pain 15(1): 61–69, 2011. 13 Hains G, Descarreaux M, Hains F: Chronic shoulder pain of myofascial origin: a randomized clinical trial using ischemic compression therapy. J. Manipulative Physiol. Ther. 33(5): 362–369, 2010.