Quantification of Myofascial Taut Bands

Evaluation of the Reproducibility of MR Elastography Measurements of the Lumbar Back Muscles

BACKGROUND

MR elastography (MRE) may provide quantitative imaging biomarkers of lumbar back muscles (LBMs), complementing MRI in spinal diseases by assessing muscle mechanical properties. However, reproducibility analyses for MRE of LBM are lacking.

PURPOSE

To assess technical failure, within-day and inter-day reproducibility, robustness with the excitation source positioning, and inter-observer agreement of MRE of muscles.

STUDY TYPE

Prospective.

SUBJECTS

Seventeen healthy subjects (mean age 28 ± 4 years; 11 females).

FIELD STRENGTH/SEQUENCE

1.5 T, gradient-echo MRE, T1-weighted turbo spin echo.

ASSESSMENT

The pneumatic driver was centered at L3 level. Four MRE were performed during two visits, 2-4 weeks apart, each consisting of two MRE with less than 10 minutes inter-scan interval. At Visit 1, after the first MRE, the coil and driver were removed, then reinstalled. The MRE was repeated. At Visit 2, following the first MRE, only the driver was moved down 5 cm. The MRE was repeated. Two radiologists segmented the multifidus and erector spinae muscles.

STATISTICAL TESTS

Paired t-test, analysis of variance, intraclass correlation coefficients (ICCs). P-values <0.05 were considered statistically significant.

RESULTS

Mean stiffness of LBM ranged from 1.44 to 1.60 kPa. Mean technical failure rate was 2.5%. Inter-observer agreement was excellent (ICC ranging from 0.82 [0.64-0.96] to 0.99 [0.98-0.99] in the multifidus, and from 0.85 [0.69-0.92] to 0.99 [0.97-0.99] in the erector spinae muscles). Within-day reproducibility was fair in the multifidus (ICC: 0.53 [0.47-0.77]) and good in the erector spinae muscles (ICC: 0.74 [0.48-0.88]). Reproducibility after moving the driver was excellent in both multifidus (ICC: 0.85 [0.69-0.93]) and erector spinae muscles (ICC: 0.84 [0.67-0.92]). Inter-day reproducibility was excellent in the multifidus (ICC: 0.76 [0.48-0.89]) and poor in the erector spinae muscles (ICC: 0.23 [-0.61 to 0.63]).

DATA CONCLUSION

MRE of LBM provides measurements of stiffness with fair to excellent reproducibility and excellent inter-observer agreement. However, inter-day reproducibility in the multifidus muscles indicated that the herein used MRE protocol may not be optimal for this muscle.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 1.

MR elastography-based slip interface imaging (SII) for functional assessment of myofascial interfaces: A feasibility study

PURPOSE

Abnormal adherence at functional myofascial interfaces is hypothesized as an important phenomenon in myofascial pain syndrome. This study aimed to investigate the feasibility of MR elastography (MRE)-based slip interface imaging (SII) to visualize and assess myofascial mobility in healthy volunteers.

METHODS

SII was used to assess local shear strain at functional myofascial interfaces in the flexor digitorum profundus (FDP) and thighs. In the FDP, MRE was performed at 90 Hz vibration to each index, middle, ring, and little finger. Two thigh MRE scans were performed at 40 Hz with knees flexed and extended. The normalized octahedral shear strain (NOSS) maps were calculated to visualize myofascial slip interfaces. The entropy of the probability distribution of the gradient NOSS was computed for the two knee positions at the intermuscular interface between vastus lateralis and vastus intermedius, around rectus femoris, and between vastus intermedius and vastus medialis.

RESULTS

NOSS map depicted distinct functional slip interfaces in the FDP for each finger. Compared to knee flexion, clearer slip interfaces and larger gradient NOSS entropy at the vastus lateralis-vastus intermedius interface were observed during knee extension, where the quadriceps are not passively stretched. This suggests the optimal position for using SII to visualize myofascial slip interface in skeletal muscles is when muscles are not subjected to any additional force.

CONCLUSION

The study demonstrated that MRE-based SII can visualize and assess myofascial interface mobility in extremities. The results provide a foundation for investigating the hypothesis that myofascial pain syndrome is characterized by changes in the mobility of myofascial interfaces.

Objective Methods of Muscle Tone Diagnosis and Their Application-A Critical Review

"Muscle tone" is a clinically important and widely used term and palpation is a crucial skill for its diagnosis. However, the term is defined rather vaguely, and palpation is not measurable objectively. Therefore, several methods have been developed to measure muscle tone objectively, in terms of biomechanical properties of the muscle. This article aims to summarize these approaches. Through database searches, we identified those studies related to objective muscle tone measurement in vivo, in situ. Based on them, we described existing methods and devices and compared their reliability. Furthermore, we presented an extensive list of the use of these methods in different fields of research. Although it is believed by some authors that palpation cannot be replaced by a mechanical device, several methods have already proved their utility in muscle biomechanical property diagnosis. There appear to be two issues preventing wider usage of these objective methods in clinical practice. Firstly, a high variability of their reliability, and secondly, a lack of valid mathematical models that would provide the observed mechanical characteristics with a clear physical significance and allow the results to be compared with each other.

Upper trapezius muscle elasticity in cervical myofascial pain syndrome measured using real-time ultrasound shear-wave elastography

Background

Myofascial pain syndrome (MPS) is a common cause of neck pain, which is a global public health problem. Because MPS does not present morphological changes within lesioned muscles, there are no imaging diagnostic criteria for this condition. In this study, we evaluate elasticity changes in upper trapezius muscles most frequently involved in cervical MPS using real-time ultrasound shear-wave elastography, and we examine their potential diagnostic value.

Methods

We consecutively enrolled 109 right posterior neck pain patients for this prospective study. Of these, 51 were diagnosed with MPS and 58 with non-MPS in the right side of their neck. Among MPS patients, 19 fell into the 1-3 range (mild pain) for pain scores on the visual analog scale (VAS), 25 fell into the 4-6 range (moderate pain), and 7 into the 7-10 range (severe pain). MPS was diagnosed by two independent clinicians using the diagnostic criteria proposed by Simons et al. Using real-time ultrasound shear-wave elastography, we measured right trapezius mean shear-wave velocity (SWVmean). The midpoint of the line between the foramen magnum and the end of the right acromion served as measuring point. Regions of interest were scaled to span 0-8.0 m/s.

Results

Trapezius SWVmean was significantly higher in MPS patients compared with non-MPS patients (P<0.001). Stratified analysis of MPS patients according to pain severity revealed similar trapezius SWVmean between mild pain and non-MPS patients (P=0.324), however SWVmean was higher in moderate and severe pain MPS patients compared with non-MPS patients (P<0.001). The area under the curve (AUC) value for upper trapezius SWVmean in MPS patients was 0.791 (95% CI: 0.703-0.863). Corresponding sensitivity and specificity values were 86.27% (95% CI: 73.7-94.3%) and 62.07% (95% CI: 48.4-74.5%). Stratified analysis of MPS patients by pain severity produced the following AUC values for trapezius SWVmean in MPS patients with mild, moderate, and severe pain: 0.578 (95% CI: 0.460-0.690), 0.899 (95% CI: 0.814-0.955), and 0.983 (95% CI: 0.914-0.999), respectively.

Conclusions

Elasticity changes and increased stiffness in the trapezius occur in cervical MPS patients with moderate and severe pain. The SWVmean parameter reflecting trapezius muscle elasticity may be valuable for successful screening of cervical MPS, especially in patients with moderate and severe pain.

Myofascial Pain Syndrome: A Nociceptive Condition Comorbid with Neuropathic or Nociplastic Pain

Myofascial pain syndrome is featured by the presence of myofascial trigger points (TrPs). Whether TrPs are primary or secondary phenomena or if they relate to central or peripheral nervous system disorders is controversial. Referred pain, a cardinal sign of TrPs, is a central phenomenon driven by peripheral input. In 2021, the International Association for the Study of Pain (IASP) proposed a clinical criteria and grading system for classifying patients with pain on nociceptive, neuropathic, or nociplastic phenotypes. Myofascial TrP pain has been traditionally categorized as a nociceptive phenotype; however, increasing evidence supports that this condition could be present in patients with predominantly nociplastic pain, particularly when it is associated with an underlying medical condition. The clinical response of some therapeutic approaches for managing TrPs remains unclear. Accordingly, the ability to classify myofascial TrP pain into one of these phenotypes would likely be critical for producing more successful clinical treatment outcomes by a precision medicine approach. This consensus paper presents evidence supporting the possibility of subgrouping individuals with myofascial TrP pain into nociceptive, nociplastic, or mixed-type phenotype. It is concluded that myofascial pain caused by TrPs is primarily a nociceptive pain condition, is unlikely to be classified as neuropathic or nociplastic, but can be present in patients with predominantly neuropathic or nociplastic pain. In the latter cases, management of the predominant central pain problem should be a major treatment goal, but the peripheral drive from TrPs should not be ignored, since TrP treatment has been shown to reduce sensitization-associated symptomatology in nociplastic pain conditions, e.g., fibromyalgia.

Viscoelasticity in trapezius myofascial pain syndrome: quantitative assessment using Real-Time Shear-Wave Elastography

OBJECTIVE

To investigate the differences in the viscoelastic properties between normal trapezius muscles and those in patients with trapezius myofascial pain syndrome (MPS) using real-time shear-wave elastography (SWE).

MATERIALS AND METHODS

This study included 31 patients with trapezius MPS and 31 volunteers. Sixty-one trapezius muscles (41 and 20 on the affected and non-affected side, respectively) of patients with MPS and 62 normal trapezius muscles in volunteers were assessed. Conventional ultrasonic parameters, including skeletal muscle thickness, resistance index (RI), and mean shear wave velocity (SWVmean) of trapezius muscles, were obtained in the seated position with the shoulders and neck relaxed. The daily neck leaning time (unit:hours) of all participants was obtained using a questionnaire.

RESULTS

Ultrasound showed no statistically significant differences in thickness or RI of the trapezius muscles of the affected and non-affected sides in MPS patients versus normal trapezius muscles (p = 0.976 and 0.106, respectively). In contrast, the SWVmean of trapezius muscles in patients with MPS was significantly higher than that of normal trapezius muscles in both the affected and non-affected sides (4.41 ± 1.02 m/s vs. 3.35 ± 0.79 m/s, p < 0.001; 4.05 ± 0.63 m/s vs. 3.35 ± 0.79 m/s, p = 0.002). There was no significant difference between the SWVmean of the trapezius muscles on the affected and non-affected sides in patients with MPS (4.41 ± 1.02 m/s vs. 4.05 ± 0.63 m/s, p = 0.225). Correlation analysis showed that daily neck forward time was positively correlated with the SWVmean of the trapezius muscles on the affected and non-affected sides in patients with MPS (r = 0.635, p < 0.001; r = 0.576, p = 0.008).

CONCLUSION

SWE can quantitatively evaluate stiffness of trapezius muscles in patients with trapezius MPS. The stiffness of both affected and non-affected trapezius muscles increased in patients with trapezius MPS, and the degree of increase positively correlated with the time of cervical forward leaning.

Myogenous Temporomandibular Disorders: Diagnostic Concepts and Prospective Pilot Study on Extracorporeal Shockwave Therapy

The aims of this article are to discuss the current, and potential future directions, in the diagnosis of myogenous temporomandibular disorders (M-TMD), as well as to report a pilot study to investigate the feasibility and clinical outcomes of extracorporeal shockwave therapy (ESWT) in the treatment of M-TMD. Forty-one adult patients presented with M-TMD were recruited into the study and randomized into two groups: Group 1 received ESWT treatment, whereas Group 2 received placebo treatment. The variables investigated were pain, measured by a numerical rating scale (NRS) and mouth opening. Twenty-six patients (Group 1: n = 14, mean age = 45.3 (16.7) years; Group 2: n = 12, mean age = 46.8 (19.7) years) completed 1-year follow up and were included into the final analysis. In both groups, reduction in pain and increase in MO (unassisted maximum, assisted maximum, and pain-free) were seen at post-treatment 1 year. There were more reduction in pain and increase in all MO in Group 1 than Group 2, but statistical significance was not detected. No major complications were encountered in this study. Although significant differences were not seen between groups, this prospective pilot study provided preliminary evidence that ESWT is safe and potentially beneficial in the treatment of M-TMD.

Clinical features of neck and shoulder pain (Katakori) in Japanese hospital workers

Background:

Non-specific pain or discomfort in the neck and shoulder girdle, called katakori in Japanese, is a common, chronic musculoskeletal condition worldwide. However, its various clinical features are incompletely characterized, even among medical professionals. We aimed to clarify factors affecting katakori and to investigate objectively the associated neck muscle stiffness and skeletal muscle volume.

Methods:

All staff members at our private hospital were surveyed about their lifestyle, physical and mental status, and katakori symptoms, using a self-administered questionnaire. Multiple logistic regression analysis was used to explore possible katakori risk factors. On secondary assessment, ultrasound elastography of the trapezius muscle as well as limb/trunk muscle mass were compared between subjects with severe symptoms and subjects without katakori, using propensity score matching.

Results:

Of 359 participants enrolled, nearly 75% had katakori to some degree. Spending time on a computer during work (adjusted odds ratio [aOR]: 1.82 for 3-6 hours, aOR: 2.48 for > 6 hours), being female (aOR: 3.75), and having unsatisfactory sleep (aOR: 2.92) were potential risk factors for katakori. Comparison of 13 matched pairs showed a significantly stiffer trapezius in subjects with severe katakori symptoms, but no apparent differences in limb/trunk muscle mass.

Conclusions:

Katakori was particularly prevalent in our hospital staff. Possible risk factors for disabling katakori were doing long-term computer work, being female, and having unsatisfactory sleep. Symptoms seem to be associated with elevated neck muscle stiffness. These findings could guide working condition improvements to mitigate katakori.

Assessment of Myofascial Trigger Points via Imaging: A Systematic Review

ABSTRACT

This study systematically reviewed the published literature on the objective characterization of myofascial pain syndrome and myofascial trigger points using imaging methods. PubMed, Embase, Ovid, and the Cochrane Library databases were used, whereas citation searching was conducted in Scopus. Citations were restricted to those published in English and in peer-reviewed journals between 2000 and 2021. Of 1762 abstracts screened, 69 articles underwent full-text review, and 33 were included. Imaging data assessing myofascial trigger points or myofascial pain syndrome were extracted, and important qualitative and quantitative information on general study methodologies, study populations, sample sizes, and myofascial trigger point/myofascial pain syndrome evaluation were tabulated. Methodological quality of eligible studies was assessed based on the Quality Assessment of Diagnostic Accuracy Studies criteria. Biomechanical properties and blood flow of active and latent myofascial trigger points assessed via imaging were found to be quantifiably distinct from those of healthy tissue. Although these studies show promise, more studies are needed. Future studies should focus on assessing diagnostic test accuracy and testing the reproducibility of results to establish the best performing methods. Increasing methodological consistency would further motivate implementing imaging methods in larger clinical studies. Considering the evidence on efficacy, cost, ease of use and time constraints, ultrasound-based methods are currently the imaging modalities of choice for myofascial pain syndrome/myofascial trigger point assessment.

Is Shear-Wave Elastography a Clinical Severity Indicator of Myofascial Pain Syndrome? An Observational Study

Since manual palpation is a subjective procedure for identifying and differentiate Myofascial Trigger Points -MTrPs-, the use of Shear Wave Elastography -SWE- as an objective alternative is increasing. This study aimed to analyze pain pressure thresholds -PPTs- and SWE differences between active MTrPs, latent MTrPs and control points located in the upper trapezius to analyze the association of SWE features with clinical severity indicators (e.g., pain extension area, PPTs, neck pain and neck disability). An observational study was conducted to calculate the correlation and to analyze the differences of sociodemographic, clinical and SWE features on 34 asymptomatic subjects with latent MTrPs and 19 patients with neck pain and active MTrPs. Significant PPT differences between active with latent MTrPs (p < 0.001) and control points (p < 0.001) were found, but no differences between latent MTrPs and control points (p > 0.05). No stiffness differences were found between active MTrPs with latent MTrPs or control points (p > 0.05). However, significant control point stiffness differences between-samples were found (p < 0.05). SWE showed no significant correlation with clinical severity indicators (p > 0.05). No stiffness differences between active and latent MTrPs were found. Neck pain patients showed increased control point stiffness compared with asymptomatic subjects. SWE showed no association with clinical severity indicators.

Combined T2 Mapping and Diffusion Tensor Imaging: A Sensitive Tool to Assess Myofascial Trigger Points in a Rat Model

Background

Myofascial trigger points (MTrPs) are defined as very small and hypersensitive points in skeletal muscle that are palpable, and produce localized pain on compression. The aim of this study was to explore the feasibility of combining T2 mapping with diffusion tensor imaging (DTI) for assessing MTrPs in a rat model and to investigate properties of the pathophysiological mechanisms.

Methods

Twenty-four Sprague-Dawley rats (model group, n = 14; control group, n = 10) underwent a magnetic resonance imaging (MRI) examination on a 3 T-MRI-scanner with a protocol consisting of T2 mapping and DTI. The MTrPs were established by blunt strike in combination with eccentric exercise. Enzyme-linked immunosorbent assays (ELISAs) were used to detect the levels of interleukin-1ß (IL-1ß) and interleukin-2 (IL-2) and their results were correlated with T2 values. Parameters from MRI including T2 values, fractional anisotropy (FA), axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD) were compared between the two groups. Histological analysis was applied to provide an additional supply for MRI findings.

Results

The MTrPs of rats displayed significantly increased T2 values and FA (= 0.000) compared with normal controls, whereas MD and RD values were significantly lower (P= 0.031, = 0.000, respectively). There was no statistically significant difference in AD between the two groups (P= 0.400). These differences were accompanied by elevated levels of IL-1ß and interleukin-2 IL-2 in the MTrP group compared with controls. T2 values were positively correlated with elevated IL-1ß levels (r = 0.543, P < 0.05) but were not correlated with IL-2 levels (P > 0.05).

Conclusion

Combining T2 and DTI sequences creates a sensitive tool to assess MTrPs in a rat model. These data clarify a hypothesis that a trigger point is a chronic and mild muscle injury with inflammation.

Properties of muscle nodules recognized by manual physical therapy practitioners

[Purpose] The purpose of this study was to describe the properties of muscle nodules (kinkoketsu) recognized by manual physical therapy practitioners. [Participants and Methods] A total of one hundred and thirty-three physical therapists, occupational therapists, judo therapists, and acupuncturists participated in this study. The shape, size, direction, depth, and hardness of muscle nodules, often treated in the buttocks, were investigated through the completion of a questionnaire. [Results] A total of 124 answer sheets were completed; 112 of these described the shape of muscle nodules as ellipsoidal. Of these 112 sheets, 97 effective sheets were analyzed. The results showed that the mean long axis length, short axis length, and thickness of the muscle nodules were 30.9 mm, 16.2 mm, and 9.3 mm, respectively. The most common responses on the long axis direction, depth, and hardness of the muscle nodules were the craniocaudal orientation, the second shallowest layer of 5 divisions, and the eraser level, respectively. [Conclusion] The typical muscle nodule found in the buttocks by manual physical therapy practitioners is roughly the shape of a large almond.

Patients with episodic migraine show increased T2 values of the trapezius muscles - an investigation by quantitative high-resolution magnetic resonance imaging

Background

Neck pain is frequent in patients with migraine. Likewise, evidence for inflammatory processes in the trapezius muscles is accumulating. However, non-invasive and objectively assessable correlates are missing in vivo.

Methods

Twenty-one subjects with episodic migraine (mean age: 24.6 ± 3.1 years, 18 females) and 22 controls (mean age: 23.0 ± 2.2 years, 17 females) without any history of headache prospectively underwent physical examination and quantitative magnetic resonance imaging of the trapezius muscles. A T2‐prepared turbo spin-echo sequence was acquired for manual segmentation of the trapezius muscles and extraction of mean T2 values.

Results

There were no statistically significant differences regarding age, sex, body mass index, or number of myofascial trigger points (mTrPs) between groups. All patients with migraine presented with mTrPs in the trapezius muscles. T2 of the entire trapezius muscles was significantly higher in the migraine group when compared to controls (31.1 ± 0.8 ms vs. 30.1 ± 1.1 ms; p = 0.002).

Conclusions

Elevated T2 values of the trapezius muscles may indicate subtle inflammatory processes within musculature among patients with migraine because T2 increase is likely to stem from edematous changes. Future work may validate this finding in larger cohorts, but muscle T2 might have potential to develop into a viable in vivo biomarker for muscular affection in migraine.

Reconnecting the Brain With the Rest of the Body in Musculoskeletal Pain Research

A challenge in understanding chronic musculoskeletal pain is that research is often siloed between neuroscience, physical therapy/rehabilitation, orthopedics, and rheumatology which focus respectively on 1) neurally mediated effects on pain processes, 2) behavior and muscle activity, 3) tissue structure, and 4) inflammatory processes. Although these disciplines individually study important aspects of pain, there is a need for more cross-disciplinary research that can bridge between them. Identifying the gaps in knowledge is important to understand the whole body, especially at the interfaces between the silos-between brain function and behavior, between behavior and tissue structure, between musculoskeletal and immune systems, and between peripheral tissues and the nervous system. Research on "mind and body" practices can bridge across these silos and encourage a "whole person" approach to better understand musculoskeletal pain by bringing together the brain and the rest of the body. PERSPECTIVE: Research on chronic musculoskeletal pain is limited by significant knowledge gaps. To be fully integrated, musculoskeletal pain research will need to bridge across tissues, anatomical areas, and body systems. Research on mind and body approaches encourages a "whole person" approach to better understand musculoskeletal pain.

[Efficacy of dry needling in neck pain compared with other physiotherapy techniques: A systematic review]

OBJECTIVE

To determine the efficacy of dry needling (DN) in the treatment of myofascial trigger points (MTrP) compared to other methods of physical therapy in the treatment of neck pain.

METHOD

A systematic search was carried out in the MEDLINE Complete (EBSCO), Pubmed, PEDro and Scopus databases. The quality of the studies was assessed using the standard of biases of the Cochrane Collaboration.

RESULTS

Eleven articles met the eligibility criteria. The characteristics of the participants and the results of the comparison of the application of DN with ultrasound, TENS, manual therapy techniques (passive stretching, strain-counterstrain, ischaemic pressure) and kinesiotape bandage are described.

CONCLUSION

DN was a useful technique in reducing neck pain. However, its efficacy in the treatment of cervicalgia could not be determined in comparison with other physiotherapy approaches.

Repetitive Peripheral Magnetic Stimulation (rPMS) in Subjects With Migraine-Setup Presentation and Effects on Skeletal Musculature

Purpose: Repetitive peripheral magnetic stimulation (rPMS) has been successfully applied recently in migraineurs to alleviate migraine symptoms. Symptom relief has been achieved by stimulating myofascial trigger points (mTrPs) of the trapezius muscles, which are considered part of the trigemino-cervical complex (TCC). However, effects on musculature have not been assessed in detail, and the specificity of effects to muscles considered part of the TCC yet has to be elucidated. Against this background, this study presents the setup of rPMS in migraine and evaluates effects on skeletal musculature. Materials and Methods: Thirty-seven adults (mean age: 25.0 ± 4.1 years, 36 females) suffering from migraine and presenting mTrPs according to physical examination underwent rPMS either to mTrPs in the trapezius muscles (considered part of the TCC; n = 19) or deltoid muscles (considered not part of the TCC; n = 18) during six sessions over the course of 2 weeks. Standardized questionnaires were filled in to assess any adverse events and experience with rPMS as well as satisfaction and benefits from stimulation. Algometry was performed to evaluate changes in pressure pain thresholds (PPTs). Results: All stimulation sessions were successfully performed without adverse events, with 84.2% of subjects of the trapezius group and 94.4% of subjects of the deltoid group describing rPMS as comfortable (p = 0.736). Muscular pain or tension improved in 73.7% of subjects of the trapezius group and in 61.1% of subjects of the deltoid group (p = 0.077). PPTs of the trapezius muscles clearly increased from the first to the last stimulation sessions-regardless of the stimulated muscle (rPMS to the trapezius or deltoid muscles). However, depending on the examined muscles the increase of PPTs differed significantly (subjects with stimulation of trapezius muscles: p = 0.021; subjects with stimulation of deltoid muscles: p = 0.080). Conclusion: rPMS is a comfortable method in migraineurs that can improve local muscular pain or tension. Furthermore, it is able to increase directly and indirectly the PPTs of the trapezius muscles (considered part of the TCC) when applied over mTrPs, supporting the role of the TCC in migraineurs.

Trigger Point Sensitivity Is a Differentiating Factor between Cervicogenic and Non-Cervicogenic Headaches: A Cross-Sectional, Descriptive Study

Purpose: A common factor in all forms of headache is the presence of myofascial trigger points (TrPs). The aim of this study was to compare the presentation of patients with cervicogenic headaches and patients with non-cervicogenic headaches in the sensitivity of TrPs in their upper trapezius, sternocleidomastoid, temporalis, and posterior cervical muscles. Method: This was a descriptive, cross-sectional study. The following variables were compared between patients with cervicogenic (n=20) and patients with non-cervicogenic (n=20) headaches: sensitivity (pain-pressure threshold) of TrPs in the upper trapezius, sternocleidomastoid, posterior cervical, and temporalis muscles (using a handheld, digital algometer); level of disability (using the Henry Ford Hospital Headache Disability Inventory questionnaire); demographics (age, sex); anthropometrics (BMI); and clinical presentation (duration and intensity of symptoms). The independent Student t-test and χ² test were used to determine the differences between the two groups. Effect sizes (Cohen's d) were calculated when relevant. Results: The two groups were similar in level of disability, demographic and anthropometric data, and clinical presentation. However, TrP sensitivity in the right upper trapezius (p=0.006; Cohen's d=0.96) and the left upper trapezius (p=0.003; Cohen's d=1.06) muscles was higher in the cervicogenic group. Conclusions: Increased sensitivity of TrPs in the upper trapezius muscle may be used as a differentiating factor in the diagnosis of cervicogenic headaches. This finding emphasizes the importance of integrating this muscle into the rehabilitation programs of patients with cervicogenic headache.

Proteins and Signaling Pathways Response to Dry Needling Combined with Static Stretching Treatment for Chronic Myofascial Pain in a RAT Model: An Explorative Proteomic Study

A quantitative proteomic analysis of the response to dry needling combined with static stretching treatment was performed in a rat model of active myofascial trigger points (MTrPs). 36 rats were divided into a model group (MG), a stretching group (SG) and a dry needling combined with stretching group (SDG). We performed three biological replicates to compare large-scale differential protein expression between groups by tandem mass tag (TMT) labeling technology based on nanoscale liquid chromatography mass spectrometry analysis (LC–MS/MS). Hierarchical clustering, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment and protein-protein interaction network analyses were performed for the general characterization of overall enriched proteins. For validation of the results of TMT, the candidate proteins were verified by parallel reaction monitoring (PRM) analysis. 285 differentially expressed proteins between groups were identified and quantified. Tight junction pathway played a dominant role in dry needling combined with static stretching treatment for the rat model of active MTrPs. Three candidate proteins, namely actinin alpha 3, calsequestrin-1 and parvalbumin alpha, were further validated, consistent with the results of LC–MS/MS. This is the first proteomics-based study to report the therapeutic mechanism underlying dry needling and static stretching treatment for MTrPs. Further functional verification of the potential signaling pathways and the enriched proteins is warranted.

Quantitative magnetic resonance imaging of the upper trapezius muscles - assessment of myofascial trigger points in patients with migraine

Background

Research in migraine points towards central-peripheral complexity with a widespread pattern of structures involved. Migraine-associated neck and shoulder muscle pain has clinically been conceptualized as myofascial trigger points (mTrPs). However, concepts remain controversial, and the identification of mTrPs is mostly restricted to manual palpation in clinical routine. This study investigates a more objective, quantitative assessment of mTrPs by means of magnetic resonance imaging (MRI) with T2 mapping.

Methods

Ten subjects (nine females, 25.6 ± 5.2 years) with a diagnosis of migraine according to ICHD-3 underwent bilateral manual palpation of the upper trapezius muscles to localize mTrPs. Capsules were attached to the skin adjacent to the palpated mTrPs for marking. MRI of the neck and shoulder region was performed at 3 T, including a T2-prepared, three-dimensional (3D) turbo spin echo (TSE) sequence. The T2-prepared 3D TSE sequence was used to generate T2 maps, followed by manual placement of regions of interest (ROIs) covering the trapezius muscles of both sides and signal alterations attributable to mTrPs.

Results

The trapezius muscles showed an average T2 value of 27.7 ± 1.4 ms for the right and an average T2 value of 28.7 ± 1.0 ms for the left side (p = 0.1055). Concerning signal alterations in T2 maps attributed to mTrPs, nine values were obtained for the right (32.3 ± 2.5 ms) and left side (33.0 ± 1.5 ms), respectively (p = 0.0781). When comparing the T2 values of the trapezius muscles to the T2 values extracted from the signal alterations attributed to the mTrPs of the ipsilateral side, we observed a statistically significant difference (p = 0.0039). T2 hyperintensities according to visual image inspection were only reported in four subjects for the right and in two subjects for the left side.

Conclusions

Our approach enables the identification of mTrPs and their quantification in terms of T2 mapping even in the absence of qualitative signal alterations. Thus, it (1) might potentially challenge the current gold-standard method of physical examination of mTrPs, (2) could allow for more targeted and objectively verifiable interventions, and (3) could add valuable models to understand better central-peripheral mechanisms in migraine.

International Consensus on Diagnostic Criteria and Clinical Considerations of Myofascial Trigger Points: A Delphi Study

Objective

There is no consensus on the essential diagnostic criteria for diagnosing a trigger point (TrP). In fact, a variety of diagnostic criteria are currently being used. Our aim was to conduct a Delphi panel to achieve an international consensus on the cluster of criteria needed for the TrP diagnosis to reach a consensus on the definition of active and latent TrPs and to clarify different clinical considerations about TrPs.

Methods

Following international guidelines, an international three-round Delphi survey was conducted. Questions were created based on a systematic literature search of the diagnostic criteria for TrPs.

Results

Sixty experts from 12 countries completed all rounds of the survey. A cluster of three diagnostic criteria was proposed as essential for the TrP diagnosis: a taut band, a hypersensitive spot, and referred pain. Eighty percent of the experts agreed that the referred pain elicited by a TrP can include different sensory sensations and not just pain, that is, pain spreading to a distant area, deep pain, dull ache, tingling, or burning pain. Eighty-four percent of the international experts consistently answered that the main clinical differences between active and latent TrPs are the reproduction of any of the symptoms experienced by a patient and the recognition of pain. No specific location of the pain referral area and TrP location should be expected.

Conclusions

This Delphi panel has produced an expert-based standardized definition of a TrP with a discussion of the clinical components, including the definition of referred pain and the difference between active and latent TrPs, thereby providing a foundation for future research in MPS.

Myofascial trigger points in migraine and tension-type headache

BACKGROUND

A myofascial trigger point is defined as a hyperirritable spot in skeletal muscle that is associated with a hypersensitive palpable nodule in a taut band. It has been suggested that myofascial trigger points take part in chronic pain conditions including primary headache disorders. The aim of this narrative review is to present an overview of the current imaging modalities used for the detection of myofascial trigger points and to review studies of myofascial trigger points in migraine and tension-type headache.

FINDINGS

Different modalities have been used to assess myofascial trigger points including ultrasound, microdialysis, electromyography, infrared thermography, and magnetic resonance imaging. Ultrasound is the most promising of these modalities and may be used to identify MTrPs if specific methods are used, but there is no precise description of a gold standard using these techniques, and they have yet to be evaluated in headache patients. Active myofascial trigger points are prevalent in migraine patients. Manual palpation can trigger migraine attacks. All intervention studies aiming at trigger points are positive, but this needs to be further verified in placebo-controlled environments. These findings may imply a causal bottom-up association, but studies of migraine patients with comorbid fibromyalgia syndrome suggest otherwise. Whether myofascial trigger points contribute to an increased migraine burden in terms of frequency and intensity is unclear. Active myofascial trigger points are prevalent in tension-type headache coherent with the hypothesis that peripheral mechanisms are involved in the pathophysiology of this headache disorder. Active myofascial trigger points in pericranial muscles in tension-type headache patients are correlated with generalized lower pain pressure thresholds indicating they may contribute to a central sensitization. However, the number of active myofascial trigger points is higher in adults compared with adolescents regardless of no significant association with headache parameters. This suggests myofascial trigger points are accumulated over time as a consequence of TTH rather than contributing to the pathophysiology.

CONCLUSIONS

Myofascial trigger points are prevalent in both migraine and tension-type headache, but the role they play in the pathophysiology of each disorder and to which degree is unclarified. In the future, ultrasound elastography may be an acceptable diagnostic test.

Changes in Muscle Stiffness of the Trapezius Muscle After Application of Ischemic Compression into Myofascial Trigger Points in Professional Basketball Players

The study aimed to assess the effects of compression trigger point therapy on the stiffness of the trapezius muscle in professional basketball players (Part A), and the reliability of the MyotonPRO device in clinical evaluation of athletes (Part B). Twelve professional basketball players participated in Part A of the study (mean age: 19.8 ± 2.4 years, body height 197 ± 8.2 cm, body mass: 91.8 ± 11.8 kg), with unilateral neck or shoulder pain at the dominant side. Part B tested twelve right-handed male athletes (mean ± SD; age: 20.4 ± 1.2 years; body height: 178.6 ± 7.7 cm; body mass: 73.2 ± 12.6 kg). Stiffness measurements were obtained directly before and after a single session trigger point compression therapy. Measurements were performed bilaterally over 5 points covering the trapezius muscle. The effects were evaluated using a full-factorial repeated measure ANOVA and the Bonferroni post-hoc test for equal variance. A p-value < .05 was considered significant. The RM ANOVA revealed a significant decrease in muscle stiffness for the upper trapezius muscle. Specifically, muscle stiffness decreased from 243.7 ± 30.5 to 215.0 ± 48.5 N/m (11.8%), (p = .008) (Part A). The test-retest relative reliability of trapezius muscle stiffness was found to be high (ICC from 0.821 to 0.913 for measurement points). The average SEM was 23.59 N/m and the MDC 65.34 N/m, respectively (Part B). The present study showed that a single session of compression trigger point therapy can be used to significantly decrease the stiffness of the upper trapezius among professional basketball players.

Characterizing the SEMG patterns with myofascial pain using a multi-scale wavelet model through machine learning approaches

In this paper, we introduce a newly developed multi-scale wavelet model for the interpretation of surface electromyography (SEMG) signals and validate the model's capability to characterize changes in neuromuscular activation in cases with myofascial pain syndrome (MPS) via machine learning methods. The SEMG data collected from normal (N = 30; 27 women, 3 men) and MPS subjects (N = 26; 22 women, 4 men) were adopted for this retrospective analysis. SMEGs were measured from the taut-band loci on both sides of the trapezius muscle on the upper back while he/she conducted a cyclic bilateral backward shoulder extension movement within 1 min. Classification accuracy of the SEMG model to differentiate MPS patients from normal subjects was 77% using template matching and 60% using K-means clustering. Classification consistency between the two machine learning methods was 87% in the normal group and 93% in the MPS group. The 2D feature graphs derived from the proposed multi-scale model revealed distinct patterns between normal subjects and MPS patients. The classification consistency using template matching and K-means clustering suggests the potential of using the proposed model to characterize interference pattern changes induced by MPS.

Myofascial Pelvic Pain and Related Disorders

Myofascial pelvic pain refers to pain in the pelvic floor muscles, the pelvic floor connective tissue, and the surrounding fascia. The cause is often multifactorial and requires treatment that encompasses multiple modalities. This type of pain is often associated with other abdominopelvic disorders, so providers in these specialties need to be aware of these connections. A comprehensive musculoskeletal examination, including evaluation of the pelvic floor muscles, and history are key to diagnosing myofascial pelvic pain. Treatments include physical therapy, muscle relaxers, oral neuromodulators, cognitive-behavioral therapy, and pelvic floor muscle injections.

Evidence of Generalized Muscle Stiffness in the Presence of Latent Trigger Points Within Infraspinatus

OBJECTIVE

To evaluate stiffness of infraspinatus muscle tissue, both with and without latent trigger points, using ultrasound shear wave elastography (SWE). The primary hypothesis is that muscle with a latent trigger point will demonstrate a discrete region of increased shear wave speed. The secondary hypothesis is that shear wave speed (SWS) in the region with the trigger point will be higher in patients compared with controls, and will be similar between the two groups in the uninvolved regions.

DESIGN

Case-control.

SETTING

Hospital-based outpatient physical therapy center.

PARTICIPANTS

Convenience sample (N=18) of patients (6 female, 3 male, mean age=44) (range=31-61y) diagnosed with latent trigger points in infraspinatus and matched controls without trigger points.

MAIN OUTCOME MEASURES

Shear wave speed (m/s).

RESULTS

SWS of the latent trigger point (mean=4.09±SD1.4 m/s) did not differ from the adjacent muscle tissue (3.92±1.6 m/s, P>.05), but was elevated compared to corresponding tissue in controls (2.8±0.75 m/s, P=.02). SWS was generally greater in patients' uninvolved tissue (3.83±1.6 m/s) when compared to corresponding tissue in controls (2.62±0.2 m/s, P=.05).

CONCLUSION

Although discrete regions of increased SWS corresponding to the trigger point were not observed in patients, evidence of generally increased muscle stiffness in infraspinatus was exhibited compared to healthy controls. Further study of additional muscles with SWE is warranted.

Evidence and expert opinions: Dry needling versus acupuncture (II) : The American Alliance for Professional Acupuncture Safety (AAPAS) White Paper 2016

In the United States and other Western countries, dry needling has been a topic in academic and legal fields. This White Paper is to provide the authoritative information of dry needling versus acupuncture to academic scholars, healthcare professionals, administrators, policymakers, and the general public by providing the authoritative evidence and expertise regarding critical issues of dry needling and reaching a consensus. We conclude that Dr. Travell, Dr. Gunn, Dr. Baldry and others who have promoted dry needling by simply rebranding (1) acupuncture as dry needling and (2) acupuncture points as trigger points (dry needling points). Dry needling simply using English biomedical terms (especially using "fascia" hypothesis) in replace of their equivalent Chinese medical terms. Dry needling is an over-simplified version of acupuncture derived from traditional Chinese acupuncture except for emphasis on biomedical language when treating neuromuscularskeletal pain (dry needling promoters redefined it as "myofascial pain"). Trigger points belong to the category of Ashi acupuncture points in traditional Chinese acupuncture, and they are not a new discovery. By applying acupuncture points, dry needling is actually trigger point acupuncture, an invasive therapy (a surgical procedure) instead of manual therapy. Dr. Travell admitted to the general public that dry needling is acupuncture, and acupuncture professionals practice dry needling as acupuncture therapy and there are several criteria in acupuncture profession to locate trigger points as acupuncture points. Among acupuncture schools, dry needling practitioners emphasize acupuncture's local responses while other acupuncturists pay attention to the responses of both local, distal, and whole body responses. For patients' safety, dry needling practitioners should meet standards required for licensed acupuncturists and physicians.

Posterior, Lateral, and Anterior Hip Pain Due to Musculoskeletal Origin: A Narrative Literature Review of History, Physical Examination, and Diagnostic Imaging

OBJECTIVE

The purpose of this study was to present a narrative review of the literature of musculoskeletal causes of adult hip pain, with special attention to history, physical examination, and diagnostic imaging.

METHODS

A narrative review of the English medical literature was performed by using the search terms "hip pain" AND "anterior," "lateral," and "posterior." Additionally, specific entities of hip pain or pain referral sources to the hip were searched for. We used the PubMed search engine through January 15, 2016.

RESULTS

Musculoskeletal sources of adult hip pain can be divided into posterior, lateral, and anterior categories. For posterior hip pain, select considerations include lumbar spine and femoroacetabular joint referral, sacroiliac joint pathology, piriformis syndrome, and proximal hamstring tendinopathy. Gluteal tendinopathy and iliotibial band thickening are the most common causes of lateral hip pain. Anterior hip pain is further divided into causes that are intra-articular (ie, labral tear, osteoarthritis, osteonecrosis) and extra-articular (ie, snapping hip and inguinal disruption [athletic pubalgia]). Entrapment neuropathies and myofascial pain should also be considered in each compartment. A limited number of historical features and physical examination tests for evaluation of adult hip pain are supported by the literature and are discussed in this article. Depending on the clinical differential, the gamut of diagnostic imaging modalities recommended for accurate diagnosis include plain film radiography, computed tomography, magnetic resonance imaging, skeletal scintigraphy, and ultrasonography.

CONCLUSIONS

The evaluation of adult hip pain is challenging. Clinicians should consider posterior, lateral, and anterior sources of pain while keeping in mind that these may overlap.