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.

The effect of dry needling on pain, pressure pain threshold and disability in patients with a myofascial trigger point in the upper trapezius muscle

Dry needling (DN) has been used recently by physical therapists as a therapy of choice for patients with myofascial trigger points (TrP). The purpose of this randomized controlled trial was to investigate the effect of DN in the treatment of TrPs in the upper trapezius (UT) muscle. A sample of convenience of 33 patients with TrP in the UT muscle participated in this study. Patients were randomly assigned to a standard (N = 17) or experimental group (N = 16). The treatment protocol for the standard group consisted of trigger point compression technique (TCT) on MTP, while the patients in the experimental group received DN. Pain intensity and pressure pain thresholds were assessed for both groups before and after the treatment sessions. In addition, the Disability of Arm, Hand, and Shoulder (DASH) was administered. Statistical analysis (paired t-test) revealed a significant improvement in pain, PPT and DASH scores after treatment in the experimental (DN) and standard (TCT) group compared with before treatment (P < 0.05). The ANCOVA revealed significant differences between the DN and TCT groups on the post-measurement VAS score (P = 0.01). There was, however, no significant difference between the two groups on the post-measurement score of the PPT (P = 0.08) and DASH (P = 0.34). DN produces an improvement in pain intensity, PPT and DASH and may be prescribed for subjects with TrP in UT muscles especially when pain relief is the goal of the treatment.

Dry needling of the trapezius muscle in office workers with neck pain: a randomized clinical trial

BACKGROUND

Neck pain is a frequent complaint in office workers. This pain can be caused by myofascial trigger points (MTrPs) in the trapezius muscle. This study aimed to determine the effectiveness of deep dry needling (DDN) of active MTrPs in the trapezius muscle.

METHODS

A randomized, single blinded clinical trial was carried out at the Physical Therapy Department at Physiotherapy in Women's Health Research Group at Physical Therapy Department of University of Alcalá, in Alcalá de Henares, Madrid, Spain. Forty-four office workers with neck pain and active MTrPs in the trapezius muscle were randomly allocated to either the DDN or the control group (CG). The participants in the DDN group were treated with DDN of all MTrPs found in the trapezius muscle. They also received passive stretch of the trapezius muscle. The CG received the same passive stretch of the trapezius muscle only. The primary outcome measure was subjective pain intensity, measured using a visual analogue scale (VAS). Secondary outcomes were pressure pain threshold (PPT), cervical range of motion (CROM) and muscle strength. Data were collected at baseline, after interventions and 15 days after the last treatment.

RESULTS

Differences were found between the DDN group and the CG for the VAS (P < 0.001), PPT (P < 0.001), range of motion (AROM) (P < 0.05) and strength (P < 0.05) after intervention and at the 15-day follow-up.

DISCUSSION

Deep dry needling and passive stretch seems to be more effective than passive stretch only. The effects are maintained in the short term. The results support the use of DDN in the management of trapezius muscle myofascial pain syndrome in neck pain.

Needling therapy for myofascial pain: recommended technique with multiple rapid needle insertion

Myofascial trigger point (MTrP) is a major cause of muscle pain, characterized with a hyperirritable spot due to accumulation of sensitized nociceptors in skeletal muscle fibers. Many needling therapy techniques for MTrP inactivation exist. Based on prior human and animal studies, multiple insertions can almost completely eliminate the MTrP pain forthwith. It is an attempt to stimulate many sensitive loci (nociceptors) in the MTrP region to induce sharp pain, referred pain or local twitch response. Suggested mechanisms of needling analgesia include effects related to immune, hormonal or nervous system. Compared to slow-acting biochemical effects involving immune or hormonal system, neurological effects can act faster to provide immediate and complete pain relief. Most likely mechanism of multiple needle insertion therapy for MTrP inactivation is to encounter sensitive nociceptors with the high-pressure stimulation of a sharp needle tip to activate a descending pain inhibitory system. This technique is strongly recommended for myofasical pain therapy in order to resume patient's normal life rapidly, thus saving medical and social resources.

Neurophysiological and clinical effects of dry needling in patients with upper trapezius myofascial trigger points

INTRODUCTION

Dry needling (DN) is a widely used in treatment of myofascial trigger points (MTrPs). The purpose of this pretest-posttest clinical trial was to investigate the neurophysiological and clinical effects of DN in patients with MTrPs.

METHODS

A sample of 20 patients (3 man, 17 women; mean age 31.7 ± 10.8) with upper trapezius MTrPs received one session of deep DN. The outcomes of neuromuscular junction response (NMJR), sympathetic skin response (SSR), pain intensity (PI) and pressure pain threshold (PPT) were measured at baseline and immediately after DN.

RESULTS

There were significant improvements in SSR latency and amplitude, pain, and PPT after DN. The NMJR decreased and returned to normal after DN.

CONCLUSIONS

A single session of DN to the active upper trapezius MTrP was effective in improving pain, PPT, NMJR, and SSR in patients with myofascial trigger points. Further studies are needed.

Comparison of shoulder strength in males with and without myofascial trigger points in the upper trapezius

BACKGROUND

This study was conducted in order to compare the strength of scapular elevator and shoulder abductor with and without restricted scapular elevation between male subjects with and without myofascial trigger points in the upper trapezius.

METHODS

In total, 15 male subjects with myofascial trigger points, and 15age- and weight-matched male subjects without myofascial trigger points in the upper trapezius. Each subject was measured in the strength of maximum isometric scapular elevation and shoulder abduction with and without restricted scapular elevation. Maximum isometric contractions were measured using the Smart KEMA strength measurement system. Independent t-tests were used to compare shoulder strength values between the myofascial trigger points and non- myofascial trigger points groups.

FINDING

The results showed that shoulder abductor strength in the group with myofascial trigger points (5.64kgf) was significantly lower than in the group without myofascial trigger points (11.96kgf) when scapular elevation was restricted (p<0.05). However, there was no significant difference in the strength of the scapular elevator or shoulder abductor between groups (p>0.05).

INTERPRETATION

These findings suggest that decreased strength in the shoulder abductor with restricted scapular elevation should be considered in evaluating and treating individuals with myofascial trigger points of the upper trapezius.

Comparison of ischemic compression and lumbopelvic manipulation as trigger point therapy for patellofemoral pain syndrome in young adults: A double-blind randomized clinical trial

OBJECTIVE

To compare the effectiveness of ischemic compression (IC) directly to the vastus medialis obliquus (VMO) versus lumbopelvic manipulation (LPM) in improving pain, functional status and sensitivity to mechanical stimulation of the VMO trigger point in patients with patellofemoral pain syndrome (PFPS).

PARTICIPANTS

40 patients with unilateral PFPS aged 20-30 years were selected randomly among patients with unilateral PFPS referred to physical therapy clinics of Shiraz University of Medical Sciences in Shiraz, Iran, between March 2014 and July 2014. 30 young adults participated. Participants were blinded to treatment allocation, and 15 patients were allocated to either IC or LPM.

INTERVENTIONS

Patients in both groups were treated in three sessions per week. IC consisted of three sets of continuous pressure applied for on the myofascial trigger point (MTrP) of VMO. LPM consisted of supine rotational glide manipulation of the ipsilateral lumbopelvic region of the involved knee.

MAIN OUTCOME MEASURES

Numeric pain rating scale (VAS) for pain intensity, Kujala questionnaire for functional status, and pressure pain threshold (PPT) for sensitivity to mechanical stimulation. All three were recorded before treatment, 1 week, 1 month and 3 months after the last session.

RESULTS

Both groups showed significant improvement (p < 0.05, 95% confidence interval) in pain, functional status and PPT values. However, the IC group showed greater improvements, and outcome measures remained significantly better than in the LPM group during post-intervention follow-up.

CONCLUSIONS

Both groups showed improvements throughout the study and follow-up period. However, the IC showed better short-term and long-term effectiveness than LPM for treating PFPS.

Electrophysiological characteristics according to activity level of myofascial trigger points

[Purpose] This study compared the differences in electrophysiological characteristics of normal muscles versus muscles with latent or active myofascial trigger points, and identified the neuromuscular physiological characteristics of muscles with active myofascial trigger points, thereby providing a quantitative evaluation of myofascial pain syndrome and clinical foundational data for its diagnosis. [Subjects] Ninety adults in their 20s participated in this study. Subjects were equally divided into three groups: the active myofascial trigger point group, the latent myofascial trigger point group, and the control group. [Methods] Maximum voluntary isometric contraction (MVIC), endurance, median frequency (MDF), and muscle fatigue index were measured in all subjects. [Results] No significant differences in MVIC or endurance were revealed among the three groups. However, the active trigger point group had significantly different MDF and muscle fatigue index compared with the control group. [Conclusion] Given that muscles with active myofascial trigger points had an increased MDF and suffered muscle fatigue more easily, increased recruitment of motor unit action potential of type II fibers was evident. Therefore, electrophysiological analysis of these myofascial trigger points can be applied to evaluate the effect of physical therapy and provide a quantitative diagnosis of myofascial pain syndrome.

A self-determination theory-based self-myofascial release program in older adults with myofascial trigger points in the neck and back: A pilot study

PURPOSE

To examine the effectiveness and adherence to a self-determination theory (SDT)-based self-myofascial release (SMR) program in older adults with myofascial trigger points (MTrPs), and to investigate the factors that influence participant behavioral change while conducting the program in a home setting.

METHODS

An explanatory mixed-method design was used to evaluate a 12-week SDT-based SMR program, including a 4-week group-based education and practice (EP) phase and an 8-week home-based self-management (SM) phase. Pain intensity on palpation and sensitivity to pain were assessed at baseline and the post EP and post SM phase. Focus group interviews were conducted at the post SM phase.

FINDINGS

Fifteen participants completed the study. Pain intensity and sensitivity to pain significantly improved at the post SM phase compared with the baseline. Adherence increased during the SM phase compared with that during the EP phase. Four main themes emerged as factors that influenced participant behavioral change: 1) "awareness of the effectiveness"; 2) "a sense of duty to perform the exercise"; 3) "obedience to expert instruction"; and 4) "lack of friendship."

CONCLUSIONS

These results support the effectiveness of an SDT-based SMR program for the treatment of MTrPs and in motivating older adults to participate in the program.

Immediate decrease of muscle biomechanical stiffness following dry needling in asymptomatic participants

BACKGROUND

Biomechanical muscle stiffness has been linked to musculoskeletal disorders. Assessing changes in muscle stiffness following DN may help elucidate a physiologic mechanism of DN. This study characterizes the effects of dry needling (DN) to the infraspinatus, erector spinae, and gastrocnemius muscles on biomechanical muscle stiffness.

METHOD

60 healthy participants were randomized into infraspinatus, erector spinae, or gastrocnemius groups. One session of DN was applied to the muscle in standardized location. Stiffness was assessed using a MyotonPRO at baseline, immediately post DN, and 24 h later. The presence of a localized twitch response (LTR) during DN was used to subgroup participants.

RESULTS

A statistically significant decrease in stiffness was observed in the gastrocnemius, the LTR gastrocnemius, and the LTR erector spinae group immediately following DN treatment. However, stiffness increased after 24 h. No significant change was found in the infraspinatus group.

CONCLUSIONS

DN may cause an immediate, yet transitory change in local muscle stiffness. It is unknown whether these effects are present in a symptomatic population or related to improvements in clinical outcomes. Future studies are necessary to determine if a decrease in biomechanical stiffness is related to improvement in symptomatic individuals.

Dry needling in a manual physiotherapy and therapeutic exercise protocol for patients with chronic mechanical shoulder pain of unspecific origin: a protocol for a randomized control trial

Background

Shoulder pain of musculoskeletal origin is the main cause of upper limb pain of non-traumatic origin. Despite being one of the most common reasons for consultation, there is no established protocol for treatment due to the complexity of its etiology. However, it has been shown that the presence of myofascial trigger points on the shoulder muscles is a common condition associated with patients suffering from shoulder pain. This protocol has been created which describes the design of a randomized controlled trial to evaluate the effectiveness of the inclusion of dry needling (DN) within a protocol of manual physiotherapy and therapeutic exercise in the treatment of chronic shoulder pain of unspecific origin.

Methods

Thirty-six participants aged 18–65 years will be recruited having mechanical chronic shoulder pain on unspecific origin and meeting the inclusion criteria. These will be randomized to one of two interventions, (i) DN, manual physiotherapy and therapeutic exercise or (ii) sham DN, manual physiotherapy and therapeutic exercise. The protocol will cover 6 weeks of treatment, with a 6-month follow-up. Our main outcome measure will be the Visual Analogue Scale for pain.

Discussion

This is the first study to combine the use of DN, manual physiotherapy and an exercise program with a 6-month follow-up, thus becoming a new contribution to the treatment of chronic shoulder pain, while new lines of research may be established to help determine the effects of DN on chronic shoulder pain and the frequency and proper dosage.

Trial registrations

International Standard Randomized Controlled Trial Number Register: ISRCTN30604244 (http://www.controlled-trials.com) 29 June 2016.

Structural and functional abnormalities of motor endplates in rat skeletal model of myofascial trigger spots

Myofascial trigger points (MTrPs) are defined as hyperirritable spots in a palpable taut band (TB) of skeletal muscle fibers. Knowing the formation and location of MTrPs is a great help to prevent their development and inactivate existing MTrPs. This study aimed to obtain new evidence that myofascial trigger spots (MTrSs), which are similar to human MTrPs, are found in dysfunctional motor endplates by observing the morphological characteristics of muscles and changes in biochemical substances. A total of 32 male Sprague Dawley rats were randomly divided into four groups: two control groups (i.e., C1 and C2) and two model groups (i.e., M1 and M2). C1 and M1 were used for acetylcholine (ACh) content measurement, while C2 and M2 were utilized for acetylcholinesterase (AChE) staining. In the model groups, blunt striking injury was induced and eccentric exercise was applied to the left gastrocnemius for 8 weeks. After 1 month, spontaneous electrical activity(SEA), AChE optical density (OD), muscle fiber diameter, and ACh content were measured. The results showed that extensive abnormal endplate noise (aEPN), including positive neurons, fibrillation potentials, fasciculation potential, and high amplitude (endplate spikes [EPS]), is present at MTrSs in M1. Quantitative electromyography results showed that the amplitudes of aEPN and frequency of EPS in M1 were significantly higher than those of C1. The ACh content of MTrSs in M1 was significantly higher than that in C1. The AChE OD value of M2 was significantly lower than that of C2. In addition, the diameter of the muscle fibers in the AChE-stained area was longer in M2 than in C2. In conclusion, MTrSs formed at the motor endplate with a larger diameter of muscle fibers. Excessive ACh release and decreased AChE activity at MTrSs stimulated muscle action potential and muscle contraction.

Efficacy of low-level laser therapy on pain, disability, pressure pain threshold, and range of motion in patients with myofascial neck pain syndrome: a systematic review and meta-analysis of randomized controlled trials

Low-level laser therapy (LLLT) is one of recent modalities for treatment of myofascial neck pain (MNP). Several RCTs have been conducted on its effectiveness. The aim of this comprehensive meta-analysis was to evaluate the effectiveness of LLLT on MNP. Electronic databases were searched for identifying eligible studies comparing the effectiveness of LLLT using any wavelength with placebo or active control in myofascial neck pain up to June 2022. Data related to pain intensity, pain pressure threshold (PPT), range of motion (ROM), and disability was analyzed as a pooled estimate of mean difference or standard mean difference (SMD) with 95% confidence intervals (CIs) using random/fixed-effect model. Funnel plot and Egger's linear regression test were also conducted to examine the risk of publication bias. A total of 13 randomized controlled trials were included in this systematic review and meta-analysis. The data assessing laser effectiveness on different outcomes of 556 patients were considered for meta-analysis. Pooled results revealed that LLLT was significantly effective in pain reduction (MD =  - 1.29, 95% CI =  - 2.36; - 0.23, P < 0.001). Also, secondary outcomes including PPT (SMD of 2.63, 95% CI = 0.96; 4.30, P < 0.01) and right bending ROM (SMD of 3.44, 95% CI = 0.64; 6.24, P < 0.01) were improved, while disability (MD of - 7.83, 95% CI =  - 17.1; 0.08, P = 1.34) did not improve significantly after LLLT. Our meta-data revealed that LLLT may reduce myofascial neck pain and its related outcomes. LLLT is suggested to be used by clinicians along with other therapies such as manual and exercise therapy.

Updates on therapies for chronic prostatitis/chronic pelvic pain syndrome

Prostatitis comprises of a group of syndromes that affect almost 50% of men at least once in their lifetime and makeup the majority of visits to the Urology Clinics. After much debate, it has been divided into four distinct categories by National Institutes of Health namely (1) acute bacterial prostatitis; (2) chronic bacterial prostatitis; (3) chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) which is further divided into inflammatory and non-inflammatory CP/CPPS; and (4) asymptomatic inflammatory prostatitis. CP/CPPS has been a cause of great concern for both patients and physicians because of the lack of presence of thorough information about the etiological factors along with the difficult-to-treat nature of the syndrome. For the presented manuscript an extensive search on PubMed was conducted for CP/CPPS aimed to present an updated review on the evaluation and treatment options available for patients with CP/CPPS. Several diagnostic criteria’s have been established to diagnose CP/CPPS, with prostatic/pelvic pain for at least 3 mo being the major classifying symptom along with the presence of lower urinary tract symptoms and/or ejaculatory pain. Diagnostic tests can help differentiate CP/CPPS from other syndromes that come under the heading of prostatitis by ruling out active urinary tract infection and/or prostatic infection with uropathogen by performing urine cultures, Meares-Stamey Four Glass Test, Pre- and Post-Massage Two Glass Test. Asymptomatic inflammatory prostatitis is confirmed through prostate biopsy done for elevated serum prostate-specific antigen levels or abnormal digital rectal examination. Researchers have been unable to link a single etiological factor to the pathogenesis of CP/CPPS, instead a cluster of potential etiologies including atypical bacterial or nanobacterial infection, autoimmunity, neurological dysfunction and pelvic floor muscle dysfunction are most commonly implicated. Initially monotherapy with anti-biotics and alpha adrenergic-blockers can be tried, but its success has only been observed in treatment naïve population. Other pharmacotherapies including phytotherapy, neuromodulatory drugs and anti-inflammatories achieved limited success in trials. Complementary and interventional therapies including acupuncture, myofascial trigger point release and pelvic floor biofeedback have been employed. This review points towards the fact that treatment should be tailored individually for patients based on their symptoms. Patients can be stratified phenotypically based on the UPOINT system constituting of Urinary, Psychosocial, Organ-specific, Infectious, Neurologic/Systemic and symptoms of muscular Tenderness and the treatment algorithm should be proposed accordingly. Treatment of CP/CPPS should be aimed towards treating local as well as central factors causing the symptoms. Surgical intervention can cause significant morbidity and should only be reserved for treatment-refractory patients that have previously failed to respond to multiple drug therapies.

Combined Effects of Extracorporeal Shockwave Therapy and Integrated Neuromuscular Inhibition on Myofascial Trigger Points of Upper Trapezius: A Randomized Controlled Trial

Objective

To investigate the combined effect of extracorporeal shockwave therapy (ESWT) and integrated neuromuscular inhibition (INI) on myofascial trigger points in the upper trapezius.

Methods

Sixty subjects aged 18–24 years old with active myofascial trigger points in the upper trapezius were studied. Participants were assigned randomly to either group A who received ESWT one session/week, group B who received INI three sessions/week, or group C who received ESWT in addition to INI. All groups completed 4 weeks of intervention. The following main outcome measures were evaluated at baseline and after 4 weeks of intervention: pain intensity, functional disability, pressure pain threshold (PPT), sympathetic skin response (SSR), and neuromuscular junction response (NMJR).

Results

Within-group analysis revealed a significant decline in visual analog scale (VAS), Arabic neck disability index (ANDI), and NMJR and incline in PPT and SSR latency post-intervention (p<0.001). Multiple comparison analysis showed a substantial difference between the groups, while the major changes favored group C (p<0.05).

Conclusion

Combined treatment with ESWT and INI for treating myofascial trigger points in the upper trapezius is more effective than using only one of the two approaches in terms of clinical, functional, and neurophysiological aspects.

Neurophysiological and psychophysical effects of dry versus sham needling of the infraspinatus muscle in patients with chronic shoulder pain: a randomized feasibility study

BACKGROUND

Dry needling (DN) is increasingly used for treating myofascial trigger points (MTrPs) and has shown significant effects on pain and function. This study aimed to assess feasibility of conducting a randomized sham-controlled trial and to collect preliminary data on the effects of infraspinatus DN on corticospinal excitability and mechanical pain sensitivity.

METHOD

This randomized feasibility study included adults with chronic non-traumatic shoulder pain and a infraspinatus MTrP. Participants were randomized to receive real DN or sham DN in the infraspinatus MTrP. Feasibility outcomes included data pertaining to recruitment, retention of participants, completeness and safety of assessment procedures. Neurophysiological and psychophysical outcomes included corticospinal excitability and mechanical pain sensitivity measured by active motor threshold (aMT) and pressure pain threshold (PPT), respectively. They were assessed at baseline, immediately after and 24 h post-intervention.

RESULTS

Twenty-one participants were recruited over a 6-month period. Nineteen participants completed the treatment and follow-up assessment. Motor evoked potential responses were discernible in all but 1 participant. Only 1 minor adverse event related to transcranial magnetic stimulation (mild headache) affected the measurements. No DN adverse effects were recorded in both groups. An overall completeness rate of 81% was reached, with 70% completeness in the DN group and 91% in the sham group. Data analysis revealed that real DN increased corticospinal excitability (reduced aMT) 24 h post-intervention (Mdn = - 5.96% MSO, IQR = 5.17, p = 0.04) and that sham DN triggered similar responses immediately after the intervention (Mdn = - 1.93% MSO, IQR = 1.11, p = 0.03). Increased mechanical pain sensitivity (reduced PPT) was significant only in the sham group, both immediately (Mdn = - 0.44 kg/cm2, IQR = 0.49, p = 0.01) and 24 h post-intervention (Mdn = - 0.52 kg/cm2, IQR = 1.02, p = 0.02). Changes in corticospinal excitability was positively correlated with changes in mechanical pain sensitivity in the DN group, both immediately (r = 0.77, p = 0.02) and 24 h post-intervention (r = 0.75, p = 0.05).

CONCLUSION

The present study demonstrates the feasibility of quantifying the neurophysiological and psychophysical effects of DN, and provides recommendations and guidelines for future studies. Moreover, it provides preliminary evidence that DN may increase corticospinal excitability of the infraspinatus muscle in patients with chronic shoulder pain and that the relationship of neurophysiological and psychophysical effects is promising to better understand its mechanisms of action.

TRIAL REGISTRATION

NCT04316793 ; retrospectively registered November 3, 2020.

Clinical efficacy of magnesium sulfate injection in the treatment of masseter muscle trigger points: a randomized clinical study

Objective

Myofascial pain syndrome with trigger points is the most common cause of nonodontogenic pain. Although injection of the trigger points is the most effective pain reduction treatment, many patients exhibit recurrence after a short period. Therefore, the aim of the current study was to evaluate the clinical efficacy of magnesium sulfate injections in the treatment of the masseter muscle trigger points when compared to saline injections.

Material and method

This study randomly (1:1) assigned 180 patients to one of two treatment groups based on whether their trigger points were injected with 2 ml of saline or magnesium sulfate. Pain scores, maximum mouth opening (MMO), and quality of life were measured at the pre-injection and 1, 3, and 6 months post-injection.

Results

The pain scores were significantly higher in the saline group during all follow-up assessments, whereas the MMO was significantly higher in the magnesium sulfate group up to 3 months of follow-up (p < 0.001). However, the difference in MMO ceased to be statistically significant after 6 months of follow-up (p = 0.121). Additionally, the patient’s quality of life score was significantly higher in the magnesium sulfate group compared to the saline group (p < 0.001).

Conclusion

Injection of magnesium sulfate is an effective treatment measure for myofascial trigger points. However, further studies with a proper design addressing the limitations of the current study are necessary.

ClinicalTrials: org (ID: NCT04742140) 5/2/2021.

[Myofascial trigger point: an indicator of acupoint sensitization]

OBJECTIVE

The present study is to investigate the characteristic distribution of primary pain points and referred pain areas in patients with knee-joint pain diseases, therefore revealing the correlation between the myofascial trigger point and acupoint sensitization.

METHODS

A total of 483 patients (320 men and 163 women, 36 to 72 years in age) with knee-joint pain recruited from 4 clinical centers were observed from July, 2017 to April, 2019 in the present study. The areas of primary and referred pain in these patients were detected by thumb-pressing and marked on human anatomic atlas.

RESULTS

Of the 483 enrolled participants, 336 had lesion sites or tender points around the injured knee joint, and 147 with myofascial pain syndrome showed referred pain spots (zones) in the knee joint area. In 105 patients with patellar tendonitis, epiphysitis of the tibial tubero-sity, or quadriceps tendonitis, the pain area was mainly distributed in the anterior region of the knee. In 76 patients with medial collateral ligament injury, medial meniscal lesion, goose foot bursitis or semimembranosus ending-point inflammation, the pain points mainly occurred in the medial area of the knee. In 127 patients with lateral collateral ligament, lateral meniscus lesion, iliotibial band tendonitis, popliteus or triceps tendinitis, the pain spots were found in the lateral region of the knee. In 28 patients with posterior cruciate ligament injury or popliteal fossa tendonitis, the local pain was found to be at the back of the knee. Referred pain areas were normally detected in the lateral femoral muscles (43 cases), anterior femoral muscles (39 cases), adductor group of femur (26 cases), posterior popliteal fossa muscles group (15 cases), hamstrings (13 cases) and medial leg (11 cases)．.

CONCLUSION

The primary pain areas or spots of the knee injury mainly distribute around the joint, whereas those of each muscle group lesion are often located in their respective skeletal muscle. Most of the referred pain areas often occur in the distal end of skeletal muscle and around the knee joint. Primary myofascial trigger points may be considered to be an indicator of acupoint sensitization.

Myofascial Trigger Point Identification in B-Mode Ultrasound: Texture Analysis Versus a Convolutional Neural Network Approach

OBJECTIVE

Myofascial pain syndrome (MPS) is one of the most common causes of chronic pain and affects a large portion of patients seen in specialty pain centers as well as primary care clinics. Diagnosis of MPS relies heavily on a clinician's ability to identify the presence of a myofascial trigger point (MTrP). Ultrasound can help, but requires the user to be experienced in ultrasound. Thus, this study investigates the use of texture features and deep learning strategies for the automatic identification of muscle with MTrPs (i.e., active and latent MTrPs) from normal (i.e., no MTrP) muscle.

METHODS

Participants (n = 201) were recruited from Toronto Rehabilitation Institute, and ultrasound videos of their trapezius muscles were acquired. This new data set consists of 1344 images (248 active, 120 latent, 976 normal) collected from these videos. For texture analysis, several features were investigated with varying parameters (i.e., region of interest size, feature type and pixel pair relationships). Convolutional neural networks (CNN) were also applied to observe the performance of deep learning approaches. Performance was evaluated based on the classification accuracy, micro F1-score, sensitivity, specificity, positive predictive value and negative predictive value.

RESULTS

The best CNN approach was able to differentiate between muscles with and without MTrPs better than the best texture feature approach, with F1-scores of 0.7299 and 0.7135, respectively.

CONCLUSION

The results of this study reveal the challenges associated with MTrP identification and the potential and shortcomings of CNN and radiomics approaches in detail.

The association between myofascial trigger points and the incidence of chronic functional constipation

INTRODUCTION

Chronic functional constipation (CFC) is the most prevalent type of constipation. Considering the proven effect of pelvic floor muscles dysfunction in these patients' symptom and the fascial connection between pelvic floor and abdominal and lumbopelvic muscles, this study aimed to examine the possible relationship between this muscles and CFC.

METHOD

We conveniently selected 100 patients with CFC and 100 healthy participants based on the Rome IV criteria. Two groups were asked to complete the international physical activity questionnaire and food frequency questionnaire. Then both groups were assessed for the presence of trigger points in more prevalent pain sites for each muscle by pressure algometer with 50% of their caught pressure pain threshold.

RESULTS

There were no statistical differences between two groups in the intake of calories, carbohydrates, proteins, sugar, fiber, vegetables, and wheat products. Patients had a higher consumption of fat and dairy products. for the physical activity level, a statistical difference showed that patients were less physically active. The comparison of the presence and the number of trigger points for each muscle in patients and control groups indicated more than 50% impairment, and there was a significant difference between two groups.

CONCLUSIONS

This study revealed that the relationship between myofascial trigger points of abdominal and lumbopelvic muscles and constipation. In addition to that, it seems that a sedentary life may influence CFC patients' condition. Moreover, it seems that the results of the dietary condition in patients could be because of conscious consumption of some certain foods.

[Effectiveness of invasive and non-invasive tecniques for neck myofascial pain syndrome: a systematic review]

INTRODUCTION

Myofascial pain is a muscular alteration caused by one or more myofascial trigger points and is considered one of the most frequent musculoskeletal disorders. This study compared the effectiveness of invasive and non-invasive techniques in the treatment of neck myofascial pain syndrome.

MATERIALS AND METHODS

A literature search were performed in PubMed with a combination of key words related to myofascial pain syndrome and invasive and non-invasive therapies. Articles were included according to whether they were published less than 10 years previously and other inclusion criteria. Pain intensity, pressure pain threshold, range of movement, disability and quality of life were evaluated in the 26 articles finally selected.

RESULTS

There are multiple publications on pain intensity reduction and range of movement. Reports of invasive techniques are more important than those of non-invasive techniques. However, there are only a few publications on threshold pressure pain, functionality and quality of life irrespective of the type of technique.

CONCLUSION

Invasive and non-invasive techniques are effective in the treatment of neck myofascial pain syndrome, but it is difficult to conclude the superiority of one type of technique over the other due to multiple methodological differences among the evaluated studies.

Association between myofascial trigger point therapy and conditioned pain modulation

INTRODUCTION

Myofascial trigger point therapy (MTrP) is a widely used therapeutic approach, although the underlying mechanisms remain unclear. Mechanisms discussed include peripheral involvement of muscles as well as central pain modulating processes such as the conditioned pain modulation (CPM). The aim of this study was to investigate whether the analgesic response of MTrP and the analgesic response of CPM correlate in asymptomatic participants in order to identify shared underlying mechanisms of MTrP and CPM.

METHOD

Both, CPM and MTrP protocols consisted of heat-based test stimuli (heat pain thresholds before and after the intervention) and pressure-based (conditioning) stimuli. Asymptomatic participants (n = 94) were randomly assigned to receive either mild, intense or no pressure stimuli (between-group design) to both the fingernail and the MTrP of the infraspinatus muscle (within-group design). Pressure stimuli at both locations (fingernail, MTrP) were applied with a pressure algometer for 120 s and continuously adjusted to maintain a constant pain intensity of mild or intense pain. All thermal stimuli were applied on the lower leg with a thermal stimulator.

RESULTS

A significant correlation was shown between the analgesic effect of CPM and MTrP therapy for mild (r = 0.53, p = 0.002) and intensive stimuli (r = 0.73, p < 0.001). 17.3% of the variance of the MTrP effect were explained by CPM after mild stimulation, and 47.1% after intense stimulation. Pain-related characteristics did not explain the variance within the analgesic response using a regression analysis.

CONCLUSIONS

Between the analgesic responses following MTrP and CPM paradigms, a moderate to strong correlation was observed, suggesting shared underlying mechanisms.

The effects of arm movement on reaction time in patients with latent and active upper trapezius myofascial trigger point

BACKGROUND

Myofascial pain syndrome is a significant source of mechanical pain. The aim of this study was to investigate the effects of arm movement on reaction time in females with latent and active upper trapezius myofascial trigger point.

METHODS

In this interventional study, a convenience sample of fifteen women with one active MTP, fifteen women with one latent MTP in the upper trapezius, and fifteen normal healthy women were participated. Participants were asked to stand for 10 seconds in an erect standing position. Muscle reaction times were recorded including anterior deltoid (AD), cervical paraspinal (CP) lumbar paraspinal (LP), both of upper trapezius (UT), sternocleidomastoid (SCM) and medial head of gastrocnemius (GcM). Participants were asked to flex their arms in response to a sound stimulus preceded by a warning sound stimulus. Data were analyzed using one-way ANOVA Test.

RESULTS

There was significant differences in motor time and reaction time between active and control groups (p< 0.05) except for GcM. There was no significant difference in motor time between active and passive groups except for UT without MTP and SCM (p< 0.05). Also, there were no significant differences in motor times between latent MTP and control groups. Furthermore, there was no significant difference in premotor times between the three groups.

CONCLUSION

The present study shows that patients with active MTP need more time to react to stimulus, but patients with latent MTP are similar to healthy subjects in the reaction time. Patients with active MTP had less compatibility with environmental stimulations, and they responded to a specific stimulation with variability in Surface Electromyography (SEMG).

Association between smartphone addiction and myofascial trigger points

BACKGROUND

The purpose of this study was to clarify the relationship between smartphone addiction and miyafascial trigger points in university students.

METHODS

A cross-sectional study of university students was conducted for the purpose of this study. The participants were assessed based on age, gender, dominant side, the amount of time they spent on their smartphones, the purpose of their use, and their posture. The Smartphone Addiction Scale Short Form (SAS-SF) was used to determine addictes and non-addicts. The cut-off value of SAS-SF is 31 and above for male and 33 and above for female.

RESULTS

There were 136 participants in the study. The posture score for addicts and non-addicts ones was not significantly different (p > 0,05), but the number of trigger points, maximal bending posture and trigger points in the right levator scapula and right cervical erector muscles were significantly higher in the smartphone addict participants (p < 0,05).

CONCLUSIONS

Smartphone addiction in university students is associated with postural changes and trigger points in the bilateral levator scapula and right cervical erector muscles. Public health programs should be developed to raise awareness about smartphone addiction, encourage screen breaks, and emphasize physical activity and exercise regularly.

Effectiveness of adding dry needling of the upper trapezius muscle to the usual physiotherapy for managing chronic neck pain: A randomized controlled trial with a 7-week follow-up

BACKGROUND

Myofascial pain syndrome (MPS) is a chronic condition caused by sensitive pressure regions within the muscles known as myofascial trigger points (MTrPs).

OBJECTIVE

The purpose of this randomized controlled trial (RCT) was to assess the effectiveness of adding dry needling (DN) to activate MTrPs in the upper trapezius muscle compared with usual physiotherapy among individuals with chronic neck pain.

METHODS

Thirty participants were recruited from a private clinic in Saudi Arabia. Their mean age was 29.7 ± 4.4 years. The subjects were randomized into two groups: the experimental group (application of DN to the MTrPs coupled with usual physiotherapy (n = 15)) and the control group (usual physiotherapy alone (n = 15)). The primary outcomes were pain (assessed using the visual analog scale) and disability (Neck Disability Index), and the secondary outcomes were neck active range of motion (AROM; assessed using cervical ROM) and depression (Beck's Depression Inventory).

RESULTS

Significant between-group difference in pain intensity was observed immediately post-intervention. Participants in the experimental group had significantly higher pain (mean difference = 1.27, 95% confidence interval [CI] 0.20, 2.33, p = 0.022, Cohen's d = 0.889) than those in the control group. There was no significant difference between both groups in pain intensity during the follow-up. There were no between-group differences in disability immediately post-intervention. However, there was a between-group difference in disability at follow-up; participants in the experimental group had significantly lower disability (mean difference = -3.13, 95%CI -5.07, -1.20, p = 0.003, Cohen's d = 1.211) than those in the control group. Immediately post-intervention, the experimental group showed greater flexion AROM compared to the control group, with no differences in other AROM measures. At follow-up, the experimental group exhibited significantly higher neck AROM in extension, flexion, right and left side bending, and lower depression, while no differences were observed in right- and left-rotation AROMs between groups.

CONCLUSIONS

The addition of DN to standard physiotherapy effectively improved disability, AROM (extension, flexion, and side bending), and depression among patients with chronic neck pain.