Compression at Myofascial Trigger Point on Chronic Neck Pain Provides Pain Relief through the Prefrontal Cortex and Autonomic Nervous System: A Pilot Study

Global trends and performances of infrared imaging technology studies on acupuncture: a bibliometric analysis

Objectives

To summarize development processes and research hotspots of infrared imaging technology research on acupuncture and to provide new insights for researchers in future studies.

Methods

Publications regarding infrared imaging technology in acupuncture from 2008 to 2023 were downloaded from the Web of Science Core Collection (WoSCC). VOSviewer 1.6.19, CiteSpace 6.2.R4, Scimago Graphica, and Microsoft Excel software were used for bibliometric analyses. The main analyses include collaboration analyses between countries, institutions, authors, and journals, as well as analyses on keywords and references.

Results

A total of 346 publications were retrieved from 2008 to 2023. The quantity of yearly publications increased steadily, with some fluctuations over the past 15 years. "Evidence-Based Complementary and Alternative Medicine" and "American Journal of Chinese Medicine" were the top-cited journals in frequency and centrality. China has the largest number of publications, with the Shanghai University of Traditional Chinese Medicine being the most prolific institution. Among authors, Litscher Gerhard from Austria (currently Swiss University of Traditional Chinese Medicine, Switzerland) in Europe, was the most published and most cited author. The article published by Rojas RF was the most discussed among the cited references. Common keywords included "Acupuncture," "Near infrared spectroscopy," and "Temperature," among others. Explore the relationship between acupoints and temperature through infrared thermography technology (IRT), evaluate pain objectively by functional near-infrared spectroscopy (fNIRS), and explore acupuncture for functional connectivity between brain regions were the hotspots and frontier trends in this field.

Conclusion

This study is the first to use bibliometric methods to explore the hotspots and cutting-edge issues in the application of infrared imaging technology in the field of acupuncture. It offers a fresh perspective on infrared imaging technology research on acupuncture and gives scholars useful data to determine the field's hotspots, present state of affairs, and frontier trends.

Pulsed negative pressure myofascial vacuum therapy and percutaneous electrolysis in the treatment of lateral epicondylalgia: A single-blind randomized controlled trial

BACKGROUND

Lateral Epicondylalgia (LE) represents one of the most common injuries of the upper limb. It is necessary to find effective treatments that reduce pain and increase functionality.

PURPOSE

To determine the effects of an integrated intervention of Pulsed Negative Pressure Myofascial Vacuum Therapy (VT), Percutaneous Electrolysis (PE) and eccentric exercise (EE) in the treatment of LE compared versus Manual Therapy soft tissue mobilization (MT) and Ultrasound therapy (US) and EE.

STUDY DESIGN

Single-blind randomized controlled trial.

METHODS

Forty participants, with unilateral LE, were randomly divided into two groups: VT + PE + EE group (n = 20) and MT + US + EE group (n = 20). The VT + PE + EE group received one weekly session for four weeks and a regimen of EE daily at-home, and the MT + US + EE group received 10 sessions over a period of two weeks and a regimen of EE daily at-home. Numerical pain rating scale (NPRS), range of motion (ROM) pressure pain threshold (PPT) and function (PRTEE questionnaire) were measured before treatment, at the end of treatment, and at one- and three-month follow-ups.

RESULTS

The statistically significant improvements were found post-treatment, favoring the VT + PE group in pain intensity (p < 0.001; ES = 0.408), PRTEE-S Pain (p = 0.001; ES = 0.377), PRTEE-S Specific function (p = 0.004; ES = 0.306) and PRTEE-S Total (p = 0.001; ES = 0.355). The VT + PE + EE treatment showed greater effectiveness than the MT + US + EE treatment at immediate post-treatment, as well as at the one-month and three-months follow-up.

CONCLUSIONS

VT and PE added to an EE program could be an effective treatment for pain, ROM, PPT, and function in patients with LE.

Correlation between psychosocial stresses, stress coping ability, pain intensity and degree of disability in patients with non-specific neck pain

This study was conducted to find out which factor among stress inducing factors and stress coping factors that can affect patients with non-specific neck pain has more correlation with the intensity of neck pain and the degree of disability. This study is a cross-sectional correlational study. 100 patients diagnosed with non-specific neck pain participated in this study. The characteristics of the participants in this study are as follows. There were 56 men and 44 women, with an average age of 34.11 years, height of 169.91, and weight of 66.97 kg. The participant`s pain intensity was 5.18 and disability index was 21.44. In order to evaluate the pain intensity and disability level of patients with non-specific neck pain, Numeric Pain Rating SCALE (NPRS), and Neck Disability Index (NDI) were investigated, respectively. Depression, Anxiety, Stress Scale-21 (DASS-21), and Tampa Scale of Kinesiophobia (TSK) were used to evaluate stress inducing factors. Brief Resolution Scale (BRS), Latack Coping Scale (LCS), and Pain Self-Efficacy Questionnaire (PSEQ) were used to evaluate stress coping factors. Spearman correlation coefficients were used to determine the correlation between NPRS, NDI, and DASS-21, TSK, BRS, LCS, and PSEQ in patients with non-specific neck pain. As a results of this study, the NPRS was correlated with NDI and TSK. The NPRS and NDI were found to have a moderate correlation, but they were correlated with TSK, but showed a weak correlation. The NDI was found to be correlated with TSK, DASS, BRS, and PSEQ. In addition, NDI showed a weak correlation with TSK, BRS, and PSEQ, but the DASS showed a moderate correlation, showing the strongest correlation among the factors. These outcomes suggest that psychosocial factors, particularly stress-related factors such as depression, anxiety, and fear of movement, exert a more pronounced influence on pain intensity and disability in individuals with non-specific neck pain.

Massage for neck pain

BACKGROUND

Massage is widely used for neck pain, but its effectiveness remains unclear.

OBJECTIVES

To assess the benefits and harms of massage compared to placebo or sham, no treatment or exercise as an adjuvant to the same co-intervention for acute to chronic persisting neck pain in adults with or without radiculopathy, including whiplash-associated disorders and cervicogenic headache.

SEARCH METHODS

We searched multiple databases (CENTRAL, MEDLINE, EMBASE, CINAHL, Index to Chiropractic Literature, trial registries) to 1 October 2023.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing any type of massage with sham or placebo, no treatment or wait-list, or massage as an adjuvant treatment, in adults with acute, subacute or chronic neck pain.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane. We transformed outcomes to standardise the direction of the effect (a smaller score is better). We used a partially contextualised approach relative to identified thresholds to report the effect size as slight-small, moderate or large-substantive.

MAIN RESULTS

We included 33 studies (1994 participants analysed). Selection (82%) and detection bias (94%) were common; multiple trials had unclear allocation concealment, utilised a placebo that may not be credible and did not test whether blinding to the placebo was effective. Massage was compared with placebo (n = 10) or no treatment (n = 8), or assessed as an adjuvant to the same co-treatment (n = 15). The trials studied adults aged 18 to 70 years, 70% female, with mean pain severity of 51.8 (standard deviation (SD) 14.1) on a visual analogue scale (0 to 100). Neck pain was subacute-chronic and classified as non-specific neck pain (85%, including n = 1 whiplash), radiculopathy (6%) or cervicogenic headache (9%). Trials were conducted in outpatient settings in Asia (n = 11), America (n = 5), Africa (n = 1), Europe (n = 12) and the Middle East (n = 4). Trials received research funding (15%) from research institutes. We report the main results for the comparison of massage versus placebo. Low-certainty evidence indicates that massage probably results in little to no difference in pain, function-disability and health-related quality of life when compared against a placebo for subacute-chronic neck pain at up to 12 weeks follow-up. It may slightly improve participant-reported treatment success. Subgroup analysis by dose showed a clinically important difference favouring a high dose (≥ 8 sessions over four weeks for ≥ 30 minutes duration). There is very low-certainty evidence for total adverse events. Data on patient satisfaction and serious adverse events were not available. Pain was a mean of 20.55 points with placebo and improved by 3.43 points with massage (95% confidence interval (CI) 8.16 better to 1.29 worse) on a 0 to 100 scale, where a lower score indicates less pain (8 studies, 403 participants; I2 = 39%). We downgraded the evidence to low-certainty due to indirectness; most trials in the placebo comparison used suboptimal massage doses (only single sessions). Selection, performance and detection bias were evident as multiple trials had unclear allocation concealment, utilised a placebo that may not be credible and did not test whether blinding was effective, respectively. Function-disability was a mean of 30.90 points with placebo and improved by 9.69 points with massage (95% CI 17.57 better to 1.81 better) on the Neck Disability Index 0 to 100, where a lower score indicates better function (2 studies, 68 participants; I2 = 0%). We downgraded the evidence to low-certainty due to imprecision (the wide CI represents slight to moderate benefit that does not rule in or rule out a clinically important change) and risk of selection, performance and detection biases. Participant-reported treatment success was a mean of 3.1 points with placebo and improved by 0.80 points with massage (95% CI 1.39 better to 0.21 better) on a Global Improvement 1 to 7 scale, where a lower score indicates very much improved (1 study, 54 participants). We downgraded the evidence to low-certainty due to imprecision (single study with a wide CI that does not rule in or rule out a clinically important change) and risk of performance as well as detection bias. Health-related quality of life was a mean of 43.2 points with placebo and improved by 5.30 points with massage (95% CI 8.24 better to 2.36 better) on the SF-12 (physical) 0 to 100 scale, where 0 indicates the lowest level of health (1 study, 54 participants). We downgraded the evidence once for imprecision (a single small study) and risk of performance and detection bias. We are uncertain whether massage results in increased total adverse events, such as treatment soreness, sweating or low blood pressure (RR 0.99, 95% CI 0.08 to 11.55; 2 studies, 175 participants; I2 = 77%). We downgraded the evidence to very low-certainty due to unexplained inconsistency, risk of performance and detection bias, and imprecision (the CI was extremely wide and the total number of events was very small, i.e < 200 events).

AUTHORS' CONCLUSIONS

The contribution of massage to the management of neck pain remains uncertain given the predominance of low-certainty evidence in this field. For subacute and chronic neck pain (closest to 12 weeks follow-up), massage may result in a little or no difference in improving pain, function-disability, health-related quality of life and participant-reported treatment success when compared to a placebo. Inadequate reporting on adverse events precluded analysis. Focused planning for larger, adequately dosed, well-designed trials is needed.

Autonomic Recalibration: A Promising Approach for Alleviating Myofascial Pain Explored in a Retrospective Case Series

This retrospective case series introduces autonomic recalibration (AR) as a novel approach for alleviating chronic myofascial pain. The manuscript explores the rationale, theory, and practice of AR, which targets the autonomic nervous system (ANS) to restore homeostasis and reduce pain. The involvement of the ANS in pain modulation and the role of autonomic imbalance in chronic pain are discussed, emphasizing the potential benefits of addressing autonomic dysregulation through AR. The technique combines manual interventions and patient education, relying on neuroplastic adaptations. Three diverse case reports are presented to illustrate the effectiveness of AR in patients with different sources of pain. Each case presents a unique clinical scenario, including a nine-year-old male diagnosed with spondylolisthesis, a 68-year-old male with a history of abdominal surgeries, and a 56-year-old male with chronic low back pain following lumbar fusion surgery. In all cases, AR resulted in pain relief, improved sleep, and restoration of functional abilities. These findings support the potential of AR as an effective alternative approach for myofascial pain. Further research is warranted to validate these outcomes and investigate the underlying mechanisms of AR.

The efficacy of manual therapy on HRV in those with long-standing neck pain: a systematic review

OBJECTIVES

Long-standing neck pain (LNP) is a clinical condition frequently encountered in the physical therapy clinic. LNP is a complex, multifactorial condition affecting multiple body systems including the autonomic nervous system (ANS). Traditionally, research on the impact of physical therapy on LNP has focused on self-report measures and pain scales. Heart rate variability (HRV) is an objective measure of the ANS, allowing for quantification of effects of treatment. This systematic review is intended to evaluate if manual therapy acutely affects heart rate variability in adults with long-standing neck pain.

METHODS

Pubmed, Medline, CINAHL, Google Scholar, Web of Science, and Cochrane library were used to retrieve the randomized controlled trials for this review between the years 2010-2021. Search terms included: chronic neck pain, neck pain, cervical pain, manual therapy, mobilization, manipulation, osteopathy, osteopathic or chiropractic. Heart rate variability, HRV, heart rate variation, effects, outcomes, benefits, impacts or effectiveness.

RESULTS

Of 139 articles located and screened, three full-text articles were selected for full qualitative synthesis, with a combined population of 112 subjects, 91 of which were female, with an average age of 33.7 ± 6.8 years for all subjects. MT techniques in three studies were statistically significant in improving HRV in people with LNP; however, techniques were differed across studies, while one study showed no benefit. The studies were found to be of high quality with PEDro scores ≥6.

CONCLUSIONS

Although no clear cause and effect relationship can be established between improvement in HRV with manual therapy, results supported the use of MT for an acute reduction in HRV. No one particular method of MT has proven superior, MT has been found to produce a statistically significant change in HRV. These HRV changes are consistent with decreased sympathetic tone and subjective pain.

Cluster Analysis of Subjective Shoulder Stiffness and Muscle Hardness: Associations with Central Sensitization-Related Symptoms

Background and Objectives: Understanding the relationships between subjective shoulder stiffness, muscle hardness, and various factors is crucial. Our cross-sectional study identified subgroups of shoulder stiffness based on symptoms and muscle hardness and investigated associated factors. Materials and Methods: measures included subjective stiffness, pain, muscle hardness, and factors like physical and psychological conditions, pressure pain threshold, postural alignment, heart rate variability, and electroencephalography in 40 healthy young individuals. Results: Three clusters were identified: Cluster 1 with high stiffness, pain, and muscle hardness; Cluster 2 with low stiffness and pain but high muscle hardness; and Cluster 3 with low levels of all factors. Cluster 1 had significantly higher central sensitization-related symptoms (CSS) scores than Cluster 2. Subjective stiffness is positively correlated with psychological factors. Conclusions: our results suggest that CSS impacts subjective symptom severity among individuals with similar shoulder muscle hardness.

Sensory and emotional responses to deep pressure stimulation at myofascial trigger points: a pilot study

Objective

Although manual pressure, such as that used during a massage, is often associated with pain, it can simultaneously be perceived as pleasant when applied to certain body areas. We hypothesized that stimulation of myofascial trigger points (TPs) leads to simultaneous pain and pleasure. TPs are hyperirritable points located in the taut band of the skeletal muscle.

Method

In this study, we measured the muscle tone, muscle stiffness, and pressure pain threshold of TPs and control points in the left brachioradialis muscle of 48 healthy participants. We also applied deep compression to the two points and collected subjective data on pain, pleasantness, unpleasantness, and relief.

Result

Greater muscle stiffness was observed in the TPs versus control points (t = 6.55, p < 0.001), and the pain threshold was significantly lower in the TPs (t = -6.21, p < 0.001). Unpleasantness ratings after deep compression were significantly lower in the TPs compared with control points (t = -2.68, p < 0.05). Participants experienced greater relief at the TPs compared with control points (t = 2.01, p < 0.05), although the perceived pain did not differ between the two types of points.

Conclusion

We compared the properties of TPs and control points, and found that deep compression at TPs was associated with higher muscle tone and stiffness, lower unpleasantness ratings, and higher relief ratings compared with the control points. These findings suggest that, at least for some TPs, pain and pleasantness are simultaneously elicited by deep pressure stimulation.

Dexmedetomidine inhibits abnormal muscle hypertrophy of myofascial trigger points via TNF-α/ NF-κB signaling pathway in rats

Myofascial pain syndrome (MPS) is a chronic pain disorder with inflammation-related primarily characterized by the presence of myofascial trigger points (MTrPs). Myocyte enhancer factor 2C (MEF2C) is involved in the occurrence of a variety of skeletal muscle diseases. However, it is not yet clear if MEF2C is involved in MTrPs. The purpose of this study was to investigate whether MEF2C was involved in the inflammatory pathogenesis of MTrPs. In the present study, we used RNA sequencing (RNA-seq) to compare the differential expression of myocyte enhancer factor 2C (MEF2C) in healthy participants and MTrPs participants. The widely used rat MTrPs model was established to research the upstream and downstream regulatory mechanism of MEF2C and found that MEF2C was significantly increased in patients with MTrPs. Dexmedetomidine (Dex) was injected intramuscularly in the MTrPs animal to assess its effects on MEF2C. The expression of MEF2C protein and mRNA in skeletal muscle of rats in the MTrPs group were up-regulated. In addition, the expression of TNF- α, p-P65, MLCK, and Myocilin (MyoC) was up-regulated and the mechanical pain threshold was decreased. Peripheral TNF- α injection significantly decreased the mechanical pain threshold and increased the expression of p-P65, MLCK, MEF2C, and MyoC in healthy rats. Maslinic acid increased the mechanical pain threshold and inhibited the expression of p-P65, MLCK, MEF2C, and MyoC. In addition, peripheral injection of DEX in MTrPs rats also inhibited the expression of TNF- α, p-P65, MLCK, MEF2C, and MyoC. These results suggest that MEF2C is involved in the inflammatory pathogenesis of MTrPs and DEX serves as a potential therapeutic strategy for the treatment of MPS.

Rapid Improvement in Neck Disability, Mobility, and Sleep Quality with Chronic Neck Pain Treated by Fu’s Subcutaneous Needling: A Randomized Control Study

Background

Chronic neck pain is a common musculoskeletal disorder caused by overuse of neck and upper back muscles or poor posture, and it is commonly combined with a limited range of motion in the neck and shoulders. Most cases will recover within a few days; however, the symptoms often recur easily. Fu's subcutaneous needling (FSN) is a new therapeutic approach used to treat patients with chronic neck pain. However, there is no solid evidence to support the effectiveness of FSN on chronic neck pain and disability.

Methods

Participants (n = 60) with chronic neck pain for more than 2 months with pain intensity scored by visual analog scale (VAS) more than five were enrolled in this trial. Participants were equally randomized into the FSN or transcutaneous electrical nerve stimulation (TENS) group who received interventions once a day on day 1, day 2, and day 4. They were assessed by outcome measurements during pre- and post-treatment and followed up for 15 days.

Results

The VAS was immediately reduced in the FSN and TENS groups and sustained for 15 days of follow-up (all P < 0.001). The immediate effects were also observed as the pressure pain threshold increased in the FSN group on day 2 (P=0.006) and day 4 (P=0.023) after treatment, and tissue hardness decreased by FSN on day 1 and day 2 after treatment (both P < 0.001). FSN and TENS treatment improved neck disability and mobility; moreover, FSN promoted participants to receive better sleep quality, as determined by PSQI assessment (P=0.030). TENS had no benefit on sleep quality.

Conclusion

FSN was able to relieve pain and relax muscle tightness. Notably, FSN significantly improved neck disability and mobility and enhanced sleep quality. These findings demonstrated that FSN could be an effective alternative treatment option for patients with chronic neck pain. Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT03605576, registered on July 30, 2018.

The Use of Orthostatic Device for 90 Minutes Does Not Change Cardiovascular and Biomechanical Parameters of Patients with Spinal Cord Injury

Background

Changes in autonomic function are often caused by spinal cord injuries, which lead to limited orthostatic positioning in these patients.

Objective

To investigate the cardiovascular and biomechanical parameters during 90 min of postural elevation equipment usage comparing spinal cord injury and healthy subjects.

Methods

A device was used that allowed patients with spinal cord injuries to remain in an orthostatic posture for 90 min. During this period, the physiological parameters were measured every 15 min. Cardiovascular parameters (heart rate, oxygen saturation, blood pressure, and autonomic nervous system) and biomechanical parameters of the plantar pressure distribution were evaluated. For blood pressure, heart rate, oxygen saturation, and autonomic nervous system, a two-way analysis of variance was applied. The mixed-effect model was applied to plantar pressure. The significance level was set at p < 0.05 for all statistical analyses.

Results

No differences were observed between the groups in systolic blood pressure (F = 0.07), diastolic blood pressure (F = 0.14), heart rate (F = 0.56), and oxygen saturation (F = 0.23) at any of the time intervals throughout the experiment (p > 0.05). No statistical difference was observed in the mean plantar pressure values between the groups (p = 0.35) during the period in which they remained in the orthostatic position.

Conclusion

The present study showed the absence of differences between spinal cord injury patients and control participants using the orthostatic device in terms of cardiovascular and biomechanical parameters over 90 min.

Not just sensitization: sympathetic mechanisms contribute to expand experimental referred pain

Background

Widespread pain partially depends upon sensitization of central pain mechanisms. However, mechanisms controlling pain distribution are not completely known. The present study sought to assess skin temperature variations in the area of experimentally-induced pain and potential sex differences.

Methods

Pressure-pain thresholds (PPTs) were measured on the right infraspinatus muscle. At the end of Day 0, all participants performed an eccentric exercise of the shoulder external rotators to induce muscle soreness 24 hours after. On Day 1, participants indicated on a body chart the area of pain induced by 60 seconds of suprathreshold pressure stimulation (STPS; PPT + 20%) on the right infraspinatus muscle. Skin temperature variations in the area of referred pain were recorded with an infrared thermography camera, immediately before and after the STPS.

Results

Twenty healthy, pain-free individuals (10 females) participated. On Day 0, the pre-STPS temperature was higher than the post-STPS temperature on the arm (P = 0.001) and forearm (P = 0.003). On Day 1, the pre-STPS temperature was higher than the post-STPS temperature on the shoulder (P = 0.015), arm (P = 0.001), and forearm (P = 0.010). On Day 0, the temperature decrease after STPS in females was greater than in males on the forearm (P = 0.039). On Day 1, a greater temperature decrease was found amongst females compared with males at the shoulder (P = 0.018), arm (P = 0.046), and forearm (P = 0.005).

Conclusions

These findings indicate that sympathetic vasomotor responses contribute to expand pressure-induced referred pain, especially among females.

Shedding light on pain for the clinic: a comprehensive review of using functional near-infrared spectroscopy to monitor its process in the brain

ABSTRACT

Pain is a complex experience that involves sensation, emotion, and cognition. The subjectivity of the traditional pain measurement tools has expedited the interest in developing neuroimaging techniques to monitor pain objectively. Among noninvasive neuroimaging techniques, functional near-infrared spectroscopy (fNIRS) has balanced spatial and temporal resolution; yet, it is portable, quiet, and cost-effective. These features enable fNIRS to image the cortical mechanisms of pain in a clinical environment. In this article, we evaluated pain neuroimaging studies that used the fNIRS technique in the past decade. Starting from the experimental design, we reviewed the regions of interest, probe localization, data processing, and primary findings of these existing fNIRS studies. We also discussed the fNIRS imaging's potential as a brain surveillance technique for pain, in combination with artificial intelligence and extended reality techniques. We concluded that fNIRS is a brain imaging technique with great potential for objective pain assessment in the clinical environment.

Pressing Intervention Promotes the Skeletal Muscle Repair of Traumatic Myofascial Trigger Points in Rats

Objective

To observe the effect of pressing intervention on the skeletal muscle repair of myofascial trigger points (MTrPs) in rats and explore the mechanism of pressing intervention on the deactivation of trigger points.

Methods

Thirty SPF rats were randomly divided into blank group, model group and press group, with 10 rats in each group. The MTrPs models were established by blunt striking plus eccentric exercise, and then evaluated. The press group was given a pressing intervention with a self-made device for 14 days, and the rats in the other two groups were fed normally. Soft tissue tension (STT) D_0.2 and pressure pain threshold (PPT) were measured before and after intervention. The skeletal muscle tissue at MTrPs was extracted and assessed by hematoxylin–eosin (HE) and Masson staining. The expression of collagen I, collagen III, α- smooth muscle actin (α-SMA), myosin heavy chain (MHC) and fibronectin (FN) were detected by Western Blotting. Enzyme linked immunosorbent assay (ELISA) was used to evaluate the expression of substance P (SP), 5-hydroxytryptamine (5-HT), cyclooxygenase 2 (COX-2) and prostaglandin E2 (PGE2).

Results

(1) Compared with the blank group, the PPT and D_0.2 reduced (P < 0.05) in the model group; while compared with the model group, the PPT and D_0.2 increased (P < 0.05) in the press group. (2) Compared with the blank group, the model group showed obvious spontaneous potentials with higher amplitude and frequency, which were also much higher than those of the press group (P < 0.05). (3) The HE and Masson staining results showed evident fibrosis in the muscle tissue of the model group, with a larger area of collagen fibers relative to that of the press group (P < 0.05). (4) The amount of collagen I, collagen III, FN, α- SMA, SP, 5-HT, COX-2 and PGE2 increased and the content of MHC decreased (P < 0.05) in the model group, as compared to the blank group; while all the substances (P < 0.05), instead of MHC which increased (P < 0.05), in the press group were decreased as compared to the model group.

Conclusion

Pressing intervention on the MTrPs in rats can alleviate chronic inflammation, inhibit fibrosis, promote skeletal muscle repair and relieve pain.

Pain relief associated with decreased oxyhemoglobin level in left dorsolateral prefrontal cortex

Pain in the elbow, shoulder, knee, lower back, and various other joints is relieved by adhesion of pyramidal thorn patches. To elucidate the pain relief mechanism induced by the patches, we established a quantitative method for estimating the pain reduction and investigated the brain regions that change in association with pain relief. We first attempted to quantify the pain relief using transcutaneous electric stimulation (TCES) and a visual analog scale (VAS), and then applied near-infrared spectroscopy (NIRS) to the prefrontal cortex, including the dorsolateral prefrontal cortex (DLPFC) and the orbitofrontal cortex (OFC). We also examined the salivary oxytocin levels, which are thought to reflect oxytocin secretion levels from the posterior pituitary in the brain. Application of pyramidal thorn patches to pain regions decreased the pain degree estimated using TCES and VAS. Oxyhemoglobin levels were likely to be decreased in the left DLPFC on the basis of NIRS measurements during patch treatment, suggesting that the left DLPFC is involved in pain relief. On the other hand, the salivary oxytocin levels varied widely. A potential reason for the varying salivary oxytocin levels is its utilization in the pain region as an analgesic agent. Our results suggest that the left DLPFC will become a target brain region for pain therapy.

Comparison of spinal column alignment and autonomic nervous activity using the intersegmental tenderness test in the segment above

[Purpose] The thoracolumbar supraspinous intersegmental tenderness test (ITT) in the segment above was performed to compare spinal alignment and autonomic activity in the presence or absence of pain. [Participants and Methods] Thirty young males were grouped into Th1–4 (Cardiopulmonary visceral nerves), Th5–9 (Large visceral nerve), and Th10–12 (Small visceral nerve) by ITT for the presence of pain. Measurements of the spinal alignment and autonomic function were performed. [Results] Those with ITT pain had a significantly lower range of motion in the sagittal plane at Th12, Th12–L1, and L2–3 and in the frontal plane at Th1–2, Th4–5, Th6–7, and L3–4 than those in the no pain group. On autonomic function tests, the pain group had significantly lower Total Power, LF (Low Frequency), and CVRR (Coefficient of variation of R-R interval). [Conclusion] In ITT, patients with pain at Th5–9 have a mixture of reduced sagittal tilt angle and autonomic hypofunction of the adjacent upper and lower thoracic to lumbar vertebrae.

Perceived Pain Responses to Foam Rolling Associate with Basal Heart Rate Variability

BACKGROUND

Foam rolling (FR) is a self-myofascial release technique with unclear effects on autonomic functioning, indexed by heart rate variability (HRV). FR can be perceived as painful or relaxing, which may explain interindividual HRV responses.

PURPOSE

To determine if acute FR alters resting HRV. A secondary aim was to determine if perceived pain during FR would predict HRV responses.

SETTING

Academic institution.

METHODS

In a randomized, crossover design, healthy adults (50% female) performed total body FR or control on separate days. Perceived pain ratings were obtained following FR of each muscle group and summed to generate an overall perceived pain rating. Seated measures of the mean RR interval and the natural logarithm of the root-mean square of successive RR interval differences (LnRMSSD, a parasympathetic HRV index) were obtained at 5-10 min pre-, 5-10 min post-, and 25-30 min post-FR.

RESULTS

No effects were observed for RR interval (p = .105-.561) or LnRMSSD (p = .110-.129). All effect sizes ranged from trivial-small (0.00-0.26). Changes in RR interval (r = 0.220-0.228, p = .433-.488) and LnRMSSD (r = 0.013-0.256, p = .376-.964) were not associated with pain scale sum. Baseline LnRMSSD was associated with pain scale sum (r = -0.663; p = .001).

CONCLUSION

FR did not systematically alter HRV, nor did perceived pain ratings predict HRV responses. Those with lower pre-FR HRV reported higher perceived pain during FR. Basal cardiac autonomic activity may, therefore, influence pain sensitivity to FR in healthy adults.

Expert consensus on the diagnosis and treatment of myofascial pain syndrome

Myofascial pain syndrome (MPS) is characterized by myofascial trigger points and fascial constrictions. At present, domestic and foreign scholars have not reached a consensus on the etiology and pathogenesis of MPS. Due to the lack of specific laboratory indicators and imaging evidence, there is no unified diagnostic criteria for MPS, making it easy to confuse with other diseases. The Chinese Association for the Study of Pain organized domestic experts to formulate this Chinese Pain Specialist Consensus on the diagnosis and treatment of MPS. This article reviews relevant domestic and foreign literature on the definition, epidemiology, pathogenesis, clinical manifestation, diagnostic criteria and treatments of MPS. The consensus is intended to normalize the diagnosis and treatment of MPS and be used by first-line doctors, including pain physicians to manage patients with MPS.

Influence of quantified dry cupping on soft tissue compliance in athletes with myofascial pain syndrome

PURPOSE

This study aimed to develop a quantitative dry cupping system that can monitor negative pressure attenuation and soft tissue pull-up during cupping to quantify soft tissue compliance.

METHODS

Baseball players with myofascial pain syndrome were recruited to validate the benefits of cupping therapy. Nine of 40 baseball players on the same team were diagnosed with trapezius myofascial pain syndrome; another nine players from the same team were recruited as controls. All participants received cupping with a negative pressure of 400 mmHg for 15 minutes each time, twice a week, for 4 weeks. Subjective perception was investigated using upper extremity function questionnaires, and soft tissue compliance was quantified objectively by the system.

RESULTS

During the 15-minute cupping procedure, pressure attenuation in the normal group was significantly greater than that in the myofascial group (p = 0.017). The soft tissue compliance in the normal group was significantly higher than that in the myofascial group (p = 0.050). Moreover, a 4-week cupping intervention resulted in an obvious increase in soft tissue lift in the myofascial pain group (p = 0.027), although there was no statistical difference in the improvement of soft tissue compliance. Shoulder (p = 0.023) and upper extremity function (p = 0.008) were significantly improved in both groups, but there was no significant difference between the two groups.

CONCLUSION

This quantitative cupping monitoring system could immediately assess tissue compliance and facilitate the improvement of soft tissues after cupping therapy. Hence, it can be used in athletes to improve their functional recovery and maintain soft tissues health during the off-season period.

Vacuum myofascial therapy device for non-specific neck pain. A single blind randomized clinical trial

OBJECTIVES

This study aimed to investigate the efficacy of a vacuum myofascial therapy device (VT) for improving pressure pain thresholds (PPTs), range of motion (ROM), neck pain-related disability, pain, and quality of life in patients with non-specific neck pain.

METHODS

A randomized controlled trial in which thirty-eight participants with non-specific neck pain (NP) were randomly assigned to either an experimental (VT) or a comparison physical therapy program (PTP) group. The VT group (n = 19) received five sessions of treatment with a vacuum myofascial therapy device while the PTP group (n = 19) received five sessions of massage, ultrasound therapy (US), and transcutaneous electric nerve stimulation (TENS) over two weeks. The outcome measures were the numerical pain rating scale (NPRS), range of motion, quality of life (SF-12), neck disability Index (NDI), and PPTs at the end of treatment and at one-month follow-up.

RESULTS

Although both groups experienced improvements in pain, neck disability, range of motion, and pressure pain, these only were statistically significant in the VT group. At one-month follow-up, the VT group still showed improvements in pain, neck disability, and range of motion.

DISCUSSION

Vacuum myofascial therapy applied with a device offers similar results to other vacuum-based techniques such as cupping therapy. Moreover, in this device the parameters are digitally controlled, which allows for the precise reproduction of treatment.

Sympathetic hyperinnervation in myofascial trigger points

OBJECTIVE

To evaluate the local distribution and activity of sympathetic nerves in myofascial trigger points (MTrPs) and explore the pathological mechanism of myofascial pain syndrome (MPS) using a rat model of disease.

METHODS

MPS was modeled in the model group (MG) by a combination of blunt trauma and eccentric exercise in Sprague-Dawley rats (n = 8). Eight rats were randomly assigned to the control group (CG). Histopathology was applied to detect the local conditions of the MTrPs. Tyrosine hydroxylase (TH), nerve growth factor (NGF), and norepinephrine (NE) were detected in the MTrPs to evaluate sympathetic remodeling.

RESULTS

Muscle fiber rupture, atrophy and shape irregularity were universally observed in the MTrPs. TH expression was significantly increased in the MG, as detected by immunofluorescence, and NGF and TH expression was also higher in MTrPs in the MG than in MTrPs in the CG, as determined by immunohistochemistry. Furthermore, the expression of NE was significantly increased in MTrPs, as determined by ELISA.

CONCLUSION

There was sympathetic hyperinnervation in MTrPs, which could partially explain the symptoms of MTrPs and is an interesting and useful new perspective regarding the diagnosis and treatment of MPS.

PERSPECTIVE

The sympathetic nerves in MTrPs are remodeled, leading to sympathetic hyperinnervation. Sympathetic hyperinnervation can partially explain the symptoms of MPS. The pathological mechanism of sympathetic hyperinnervation may be a new perspective for the diagnosis and treatment of MPS.

Sensor Technologies to Manage the Physiological Traits of Chronic Pain: A Review

Non-oncologic chronic pain is a common high-morbidity impairment worldwide and acknowledged as a condition with significant incidence on quality of life. Pain intensity is largely perceived as a subjective experience, what makes challenging its objective measurement. However, the physiological traces of pain make possible its correlation with vital signs, such as heart rate variability, skin conductance, electromyogram, etc., or health performance metrics derived from daily activity monitoring or facial expressions, which can be acquired with diverse sensor technologies and multisensory approaches. As the assessment and management of pain are essential issues for a wide range of clinical disorders and treatments, this paper reviews different sensor-based approaches applied to the objective evaluation of non-oncological chronic pain. The space of available technologies and resources aimed at pain assessment represent a diversified set of alternatives that can be exploited to address the multidimensional nature of pain.

Analgesic Effects of Compression at Trigger Points Are Associated With Reduction of Frontal Polar Cortical Activity as Well as Functional Connectivity Between the Frontal Polar Area and Insula in Patients With Chronic Low Back Pain: A Randomized Trial

Background

Compression of myofascial trigger points (MTrPs) in muscles is reported to reduce chronic musculoskeletal pain. Although the prefrontal cortex (PFC) is implicated in development of chronic pain, the mechanisms of how MTrP compression at low back regions affects PFC activity remain under debate. In this study, we investigated effects of MTrP compression on brain hemodynamics and EEG oscillation in subjects with chronic low back pain.

Methods

The study was a prospective, randomized, parallel-group trial and an observer and subject-blinded clinical trial. Thirty-two subjects with chronic low back pain were divided into two groups: subjects with compression at MTrPs (n = 16) or those with non-MTrPs (n = 16). Compression at MTrP or non-MTrP for 30 s was applied five times, and hemodynamic activity (near-infrared spectroscopy; NIRS) and EEGs were simultaneously recorded during the experiment.

Results

The results indicated that compression at MTrPs significantly (1) reduced subjective pain (P < 0.05) and increased the pressure pain threshold (P < 0.05), (2) decreased the NIRS hemodynamic activity in the frontal polar area (pPFC) (P < 0.05), and (3) increased the current source density (CSD) of EEG theta oscillation in the anterior part of the PFC (P < 0.05). CSD of EEG theta oscillation was negatively correlated with NIRS hemodynamic activity in the pPFC (P < 0.05). Furthermore, functional connectivity in theta bands between the medial pPFC and insula cortex was significantly decreased in the MTrP group (P < 0.05). The functional connectivity between those regions was positively correlated with subjective low back pain (P < 0.05).

Discussion

The results suggest that MTrP compression at the lumbar muscle modulates pPFC activity and functional connectivity between the pPFC and insula, which may relieve chronic musculoskeletal pain.

Trial registration

This trial was registered at University Hospital Medical Information Network Clinical Trials Registry (UMIN000033913) on 27 August 2018, at https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000038660.

Effectiveness between Dry Needling and Ischemic Compression in the Triceps Surae Latent Myofascial Trigger Points of Triathletes on Pressure Pain Threshold and Thermography: A Single Blinded Randomized Clinical Trial

BACKGROUND

Deep dry needling (DDN) and ischemic compression technic (ICT) may be considered as interventions used for the treatment of Myofascial Pain Syndrome (MPS) in latent myofascial trigger points (MTrPs). The immediate effectiveness of both DDN and ICT on pressure pain threshold (PPT) and skin temperature of the latent MTrPs of the triceps surae has not yet been determined, especially in athletes due to their treatment requirements during training and competition.

OBJECTIVE

To compare the immediate efficacy between DDN and ICT in the latent MTrPs of triathletes considering PPT and thermography measurements.

METHOD

A total sample of 34 triathletes was divided into two groups: DDN and ICT. The triathletes only received a treatment session of DDN (n = 17) or ICT (n = 17). PPT and skin temperature of the selected latent MTrPs were assessed before and after treatment.

RESULTS

Statistically significant differences between both groups were shown after treatment, showing a PPT reduction (p < 0.05) in the DDN group, while PPT values were maintained in the ICT group. There were not statistically significant differences (p > 0.05) for thermographic values before and treatment for both interventions.

CONCLUSIONS

Findings of this study suggested that ICT could be more advisable than DDN regarding latent MTrPs local mechanosensitivity immediately after treatment due to the requirements of training and competition in athletes' population. Nevertheless, further studies comparing both interventions in the long term should be carried out in this specific population due to the possible influence of delayed onset muscle soreness and muscle damage on PPT and thermography values secondary to the high level of training and competition.

Myofascial pain and treatment: Editorial a critical overview of the current myofascial pain literature - August 2019

This quarter's overview of the myofascial pain literature includes quite a few basic research papers in addition to the usual high quantity of dry needling (DN) papers. Of particular interest are a study by Fischer and colleagues studying the role of mitochondrial functions in chronic trigger points (TrPs) (Fischer et al 2018), a study by Li and associates who conducted a quantitative proteomics analysis to identify biomarkers of chronic myofascial pain and therapeutic targets of dry needling in a rat model of TrPs (Li et al 2019), and a sonography study by Mitchell et al. looking into the distances from the skin to the pleura in the context of DN (Mitchell et al 2019). A total of 33 papers are included in this overview article. We welcome Dr. Jacob Thorp to our team of authors. Dr. Thorp is a US-based physical therapist. He is Professor and Founding Director of the Physical Therapy Program at Charleston Southern University in North Charleston, SC.

Effect of manual compressive therapy on latent myofascial trigger point pressure pain thresholds

OBJECTIVE

This study compared the effects of 90 s of manual compressive therapy (MCT) on latent myofascial trigger points (LTPs) for 3 sessions per week for 4 weeks to determine changes in individual pressure pain threshold (PPT). A total of 30 (15 males, 15 females; age = 22 ± 4 y/o, height = 175 ± 18 cm, weight = 162.5 ± 57.5 kg) symptomatic subjects with LTPs volunteered for the study.

METHODS

PPT was measured at baseline and pre- and post-treatment for all 12 sessions with a pressure algometer across the 4-week treatment time frame. The MCT was applied to the control group on their LTP at pressure intended to provide a sham condition (1/10 on verbalized analog scale (VAS)). Two experimental groups had MCT applied either directly on the LTP (d-TP) or in close-proximity to their LTP (cp-TP) at moderate pressure (7/10 on VAS).

RESULTS

There was a significant increase in PPT from the first through twelfth treatment sessions (p < 0.001, partial η² = 0.914). A significant increase in PPTs between treatment groups was acutely observed from pre- to post-therapy tests (p = 0.001, partial η² = 0.146). The differences between pre- versus post-treatment PPT measures indicated significant differences (d-TP vs. control, p < 0.001; cp-TP vs. control, p = 0.007). No differences were observed between experimental groups (p = 0.215).

CONCLUSIONS

PPT continued to increase after several weeks of MCT when applied directly on or within 2.5 cm of an identified LTP compared to control.

Atraumatic Back Pain Due to Quadratus Lumborum Spasm Treated by Physical Therapy with Manual Trigger Point Therapy in the Emergency Department

Manual trigger point therapy is effective for treating myofascial pain, yet it is not frequently used in emergency department (ED) settings. A 42-year-old female presented to the ED with atraumatic back pain. Her pain was thought to be myofascial, and we obtained a physical therapy consultation. Diagnosing the patient with quadratus lumborum spasm, the physical therapist treated her in the ED using manual trigger point therapy, and completely relieved her pain without requiring any medications. Manual trigger point therapy can provide non-opioid pain relief in ED patients, and physical therapists can apply this technique effectively in the ED.

Neurophysiological Effects of High Velocity and Low Amplitude Spinal Manipulation in Symptomatic and Asymptomatic Humans: A Systematic Literature Review

STUDY DESIGN

Systematic review.

OBJECTIVE

To summarize the evidence of neurophysiological effects of spinal manipulative therapy (SMT) with a high velocity low amplitude thrust (HVLA-SMT) in asymptomatic and symptomatic humans.

SUMMARY OF BACKGROUND DATA

HVLA-SMT is effective in reducing back pain, but its mode of action is not fully understood.

METHODS

A systematic literature search (until July 2018) was conducted by a professional librarian in seven databases (Medline (OvidSP), Premedline (PubMed), EMBASE, Cochrane, CINAHL, PEDro, and Scopus). Two authors selected the studies according to the a priori described criteria and scored study quality. Only controlled studies of at least moderate quality were included. Effects of HVLA-SMT on a particular outcome measure were defined as more than one study showing a significantly greater effect of HVLA-SMT compared with the control intervention.

RESULTS

From the 18 studies included (932 participants in total), there was evidence only for an association between HVLA-SMT and changes in the autonomic nervous system, reflected in changes in heart rate variability and skin conductance. Most studies focused on healthy volunteers and none related neurophysiologic changes to pain reduction.

CONCLUSION

This systematic review points to HVLA-SMT affecting the autonomic nervous system. The effects seem to depend on the spinal level of HVLA-SMT application and might differ between healthy volunteers and pain patients. There is a need for high-quality studies that include patients, well characterized for pain duration and outcome measure baseline values, and address the relation between changes in neurophysiology and pain.

LEVEL OF EVIDENCE

2.

Effects of Local Ischemic Compression on Upper Limb Latent Myofascial Trigger Points: A Study of Subjective Pain and Linear Motor Performance

OBJECTIVE

To analyse the effect of the manual ischemic compression (IC) on the upper limb motor performance (MP) in patients with LTrPs.

MATERIALS AND METHODS

A quasiexperimental study was performed in twenty subjects allocated to either patients group with LTrPs (PG, n=10) or healthy group with no symptoms (HG, n=10). Subjective pain and linear MP (movement time and Fitts' Law) were assessed before and after a linear tapping task. Data were analysed with mixed factorial ANOVA for intergroup linear motor performance differences and dependent t-student test for intragroup pain differences.

RESULTS

PG had a linear MP lower than the HG before treatment (p < 0.05). After IC, the PG showed a significant decrease of pain (4.07 ± 1.91 p < 0.001). Furthermore, the movement time (15.70 ± 2.05 p < 0.001) and the Fitts' Law coefficient (0.80 ± 0.53 p < 0.001) were significantly reduced. However, one IC session did not allow the PG to get the same MP than the HG (p < 0.05).

CONCLUSION

The results suggest the IC effectiveness on pain and MP impairment in subjects with LTrPs. However, the MP of these patients is only partially improved after the IC application.

Concussion and the autonomic nervous system: An introduction to the field and the results of a systematic review

BACKGROUND

Recent evidence suggests that autonomic nervous dysfunction may be one of many potential factors contributing to persisting post-concussion symptoms.

OBJECTIVE

This is the first systematic review to explore the impact of concussion on multiple aspects of autonomic nervous system functioning.

METHODS

The methods employed are in compliance with the American Academy of Neurology (AAN) and PRISMA standards. Embase, MEDLINE, PsychINFO, and Science Citation Index literature searches were performed using relevant indexing terms for articles published prior to the end of December 2016. Data extraction was performed by two independent groups, including study quality indicators to determine potential risk for bias according to the 4-tiered classification scheme of the AAN.

RESULTS

Thirty-six articles qualified for inclusion in the analysis. Only three studies (one Class II and two Class IV) did not identify anomalies in measures of ANS functioning in concussed populations.

CONCLUSIONS

The evidence supports the conclusion that it is likely that concussion causes autonomic nervous system anomalies. An awareness of this relationship increases our understanding of the physical impact of concussion, partially explains the overlap of concussion symptoms with other medical conditions, presents opportunities for further research, and has the potential to powerfully inform treatment decisions.