Detecting local twitch responses of myofascial trigger points in the lower-back muscles using ultrasonography

Rha D-w, Shin JC, Kim Y-K, Jung JH, Kim YU, Lee SC. Detecting local twitch responses of myofascial trigger points in the lower-back muscles using ultrasonography.

Objective

To evaluate the role of ultrasonography for detecting local twitch responses (LTRs) of myofascial trigger points (MTrPs) in deeply located lower-back muscles.

Design

Case-control study. Active MTrP was diagnosed in all patients based on the criteria proposed by Travell and Simons in their upper-trapezius or lower-back muscles. One investigator administered trigger point injections while observing LTRs on ultrasonography. The other investigator observed LTRs visually during the procedure.

Setting

University rehabilitation hospital.

Participants

Patients (n=41; mean age, 51.8±11.8y) with MTrPs in the upper-trapezius muscles and patients (n=62; mean age, 56.8±11.9y) with MTrPs in the erector spinae or quadratus lumborum were recruited from April 29 to October 31, 2010.

Interventions

Ultrasound-guided trigger point injection.

Main Outcome Measures

LTR detection rate according to the depth of MTrPs; subjective pain intensity using a visual analog scale before and immediately after the trigger point injection.

Results

In upper-trapezius muscles, all LTRs were detected by means of both ultrasonographic and visual inspection. In the lower-back muscles, many LTRs were detected only on ultrasonography during the trigger point injection. For deep muscles, ultrasound helped identify LTRs that were not detected by using visual assessment. Pain was alleviated more significantly in the group with LTRs during trigger point injections compared with the group without LTRs.

Conclusions

These findings suggest that ultrasonography was useful for detecting LTRs of MTrPs, especially for LTRs in the deep muscles. Ultrasound guidance may improve the therapeutic efficacy of trigger point injection for treating MTrPs in the deep muscles.     

Biochemicals associated with pain and inflammation are elevated in sites near to and remote from active myofascial trigger points

Shah JP, Danoff JV, Desai MJ, Parikh S, Nakamura LY, Phillips TM, Gerber LH. Biochemicals associated with pain and inflammation are elevated in sites near to and remote from active myofascial trigger points.

Objectives

To investigate the biochemical milieu of the upper trapezius muscle in subjects with active, latent, or absent myofascial trigger points (MTPs) and to contrast this with that of the noninvolved gastrocnemius muscle.

Design

We used a microanalytic technique, including needle insertions at standardized locations in subjects identified as active (having neck pain and MTP), latent (no neck pain but with MTP), or normal (no neck pain, no MTP). We followed a predetermined sampling schedule; first in the trapezius muscle and then in normal gastrocnemius muscle, to measure pH, bradykinin, substance P, calcitonin gene-related peptide, tumor necrosis factor alpha, interleukin 1β (IL-1β), IL-6, IL-8, serotonin, and norepinephrine, using immunocapillary electrophoresis and capillary electrochromatography. Pressure algometry was obtained. We compared analyte concentrations among groups with 2-way repeated-measures analysis of variance.

Setting

A biomedical research facility.

Participants

Nine healthy volunteer subjects.

Interventions

Not applicable.

Main Outcome Measures

Preselected analyte concentrations.

Results

Within the trapezius muscle, concentrations for all analytes were higher in active subjects than in latent or normal subjects (P<.002); pH was lower (P<.03). At needle insertion, analyte concentrations in the trapezius for the active group were always higher (pH not different) than concentrations in the gastrocnemius muscle. At all times within the gastrocnemius, the active group had higher concentrations of all analytes than did subjects in the latent and normal groups (P<.05); pH was lower (P<.01).

Conclusions

We have shown the feasibility of continuous, in vivo recovery of small molecules from soft tissue without harmful effects. Subjects with active MTPs in the trapezius muscle have a biochemical milieu of selected inflammatory mediators, neuropeptides, cytokines, and catecholamines different from subjects with latent or absent MTPs in their trapezius. These concentrations also differ quantitatively from a remote, uninvolved site in the gastrocnemius muscle. The milieu of the gastrocnemius in subjects with active MTPs in the trapezius differs from subjects without active MTPs.     

Myofascial trigger points in early life

OBJECTIVE: To determine whether latent myofascial trigger points (MTPs) can be identified in healthy infants and in healthy adult subjects. DESIGN: Blind comparison. SETTING: Ambulatory. PARTICIPANTS: A convenience sample of 60 healthy adults and 60 infants (age range, 0-12mo). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: An algometer was used to measure the pressure pain threshold (PPT) on 3 different sites, including a midpoint (assumed to be the MTP site) in the brachioradialis muscle. RESULTS: The mean PPT values at the MTP site were significantly lower than the other sites in the adult muscles. However, no significant differences in PPT values among these 3 sites were found in the infants. Taut bands were found in all the adult muscles but none in the infants. CONCLUSIONS: In the adult subjects, the midpoint of brachioradialis muscle was significantly more irritable than other sites and the midpoint was probably a latent MTP. However, in the infants younger than 1 year old, such a phenomenon could not be observed in this study. It is very likely that the latent MTPs might not exist in early life, but develop in later life.     

A distinct pattern of myofascial findings in patients after whiplash injury

Ettlin T, Schuster C, Stoffel R, Brüderlin A, Kischka U. A distinct pattern of myofascial findings in patients after whiplash injury.

Objective

To identify objective clinical examinations for the diagnosis of whiplash syndrome, whereby we focused on trigger points.

Design

A cross-sectional study with 1 measurement point.

Setting

A quiet treatment room in a rehabilitation center.

Participants

Patients (n=124) and healthy subjects (n=24) participated in this study. Among the patient group were patients with whiplash-associated disorders (n=47), fibromyalgia (n=21), nontraumatic chronic cervical syndrome (n=17), and endogenous depression (n=15).

Interventions

Not applicable.

Main Outcome Measure

Each patient and control subject had a manual examination for trigger points of the semispinalis capitis, trapezius pars descendens, levator scapulae, scalenus medius, sternocleidomastoideus, and masseter muscles bilaterally.

Results

Forty (85.1%) of the patients with whiplash had positive trigger points in the semispinalis capitis muscle. The patients with whiplash had a significantly higher prevalence of positive trigger points in the semispinalis capitis muscle than any of the control groups (P<.05). For the other examined muscles, the prevalence of trigger points in the patients with whiplash did not differ significantly from the patients with fibromyalgia or nontraumatic chronic cervical syndrome. It did differ from the patients with endogenous depression and the healthy controls.

Conclusions

Patients with whiplash showed a distinct pattern of trigger point distribution that differed significantly from other patient groups and healthy subjects. The semispinalis capitis muscle was more frequently affected by trigger points in patients with whiplash, whereas other neck and shoulder muscles and the masseter muscle did not differentiate between patients with whiplash and patients with nontraumatic chronic cervical syndrome or fibromyalgia.     

超声引导下针刺触发点治疗足底筋膜炎

目的 观察超声引导下针刺触发点治疗足底筋膜炎的临床效果。方法 选取48例足底筋膜炎患者，并随机分为2组，对单纯组（n=24）采用单纯非负重跖腱膜拉伸训练，联合组（n=24）采用超声引导下针刺触发点结合非负重跖腱膜拉伸训练；分别于治疗前（T₀）及治疗后1个月（T₁）、3个月（T₂）对患者进行"第1步"数字疼痛评分（NPRS）、美国矫形外科足踝协会踝-后足功能评分（AOFAS）以及36条目健康调查量表中生理（PCS）和心理（MCS）评分。结果 治疗前后2组NPRS、AOFAS、PCS和MCS评分总体差异均有统计学意义（P均<0.01），治疗后均较治疗前改善。联合组T₁和T₂的NPRS均低于单纯组（P均<0.01），T₁和T₂的AOFAS、PCS评分均高于单纯组（P均<0.05），而2组间T₁和T₂的MCS评分差异均无统计学意义（P均>0.05）。结论 超声引导下针刺触发点联合拉伸训练和单纯非负重跖腱膜拉伸训练对于足底筋膜炎均有效，前者缓解疼痛和改善足踝功能效果更佳。     

Comparison of high-power pain threshold ultrasound therapy with local injection in the treatment of active myofascial trigger points of the upper trapezius muscle

Unalan H, Majlesi J, Aydin FY, Palamar D. Comparison of high-power pain threshold ultrasound therapy with local ?njection in the treatment of active myofascial trigger points of the upper trapezius muscle.

Objective

To compare the effects of high-power pain threshold ultrasound (HPPTUS) therapy and local anesthetic injection on pain and active cervical lateral bending in patients with active myofascial trigger points (MTrPs) of the upper trapezius muscle.

Design

Randomized single-blinded controlled trial.

Setting

Physical medicine and rehabilitation department of university hospital.

Participants

Subjects (N=49) who had active MTrPs of the upper trapezius muscle.

Interventions

HPPTUS or trigger point injection (TrP).

Main Outcome Measures

Visual analog scale, range of motion (ROM) of the cervical spine, and total length of treatments.

Results

All patients in both groups improved significantly in terms of pain and ROM, but there was no statistically significant difference between groups. Mean numbers of therapy sessions were 1 and 1.5 in the local injection and HPPTUS groups, respectively.

Conclusions

We failed to show differences between the HPPTUS technique and TrP injection in the treatment of active MTrPs of the upper trapezius muscle. The HPPTUS technique can be used as an effective alternative to TrP injection in the treatment of myofascial pain syndrome.     

Shock waves as treatment of mouse myofascial trigger points

Introduction

An abnormal increase in spontaneous neurotransmission can induce subsynaptic knots in the myocyte called myofascial trigger points. The treatment of choice is to destroy these trigger points by inserting needles. However, 10% of the population has a phobia of needles, blood, or injuries. Therefore, the objective of this study is to verify the usefulness of shock waves in the treatment of myofascial trigger points.

Methods

Two groups of mice have been developed for this: healthy muscles treated with shock waves; trigger points affected muscles artificially generated with neostigmine and subsequently treated with shock waves. Muscles were stained with methylene blue, PAS-Alcian Blue, and labeling the axons with fluorescein and the acetylcholine receptors with rhodamine. Using intracellular recording the frequency of miniature endplate potentials (mEPPs) was recorded and endplate noise was recorded with electromyography.

Results

No healthy muscles treated with shock waves showed injury. Twitch knots in mice previously treated with neostigmine disappeared after shock wave treatment. Several motor axonal branches were retracted. On the other hand, shock wave treatment reduces the frequency of mEPPs and the number of areas with endplate noise.

Discussion

Shock waves seem to be a suitable treatment for myofascial trigger points. In the present study, with a single session of shock waves, very relevant results have been obtained, both functional (normalization of spontaneous neurotransmission) and morphological (disappearance of myofascial trigger points). Patients with a phobia of needles, blood, or injuries who cannot benefit from dry needling may turn to noninvasive radial shock wave treatment.     

Are tender points associated with cervical radiculopathy?

OBJECTIVE: To determine if there is an association between cervical radiculopathy and tender spots in the neck and upper extremity on the side of radiculopathy. DESIGN: Prospective cross-sectional study. SETTING: Outpatient spine clinic within an academic institution. PARTICIPANTS: Convenience sample of 16 subjects with unilateral cervical radiculopathy. Twelve subjects had C7 radiculopathy and 4 had C6 or C8 radiculopathy. INTERVENTION: Bilateral pain-pressure threshold measurement (14 muscles) of the neck and upper extremity. MAIN OUTCOME MEASURE: Side-to-side difference in pain-pressure threshold. RESULTS: Differences in frequency of tender spots were found only in the deltoid and flexor carpi radialis. Overall, more tender spots were found on the side of radiculopathy (75 vs 34, P < .01). Among subjects with C7 radiculopathy, the number of tender spots in C7 innervated muscles was greater on the side of radiculopathy (23 vs 7, P < .02). In contrast, no significant difference in the number of tender spots between sides was found when only non-C7 innervated muscles (P > 0.1) were considered. CONCLUSIONS: Cervical radiculopathy was associated with increased tender spots on the side of radiculopathy, with predilection toward muscles innervated by the involved nerve root.     

按压肌筋膜触发点对功能性踝关节不稳患者的疗效研究

摘要目的：探讨按压肌筋膜触发点在功能性踝关节不稳（functional ankle instability, FAI）患者中的临床疗效。方法：选取西南大学医院康复医学中心门诊2021年5月—8月就诊的功能性踝关节不稳患者29例,随机分为试验组15例和对照组14例。试验组在踝关节平衡训练基础上增加按压肌筋膜触发点技术,对照组采用BOSU球进行踝关节平衡训练。分别在基线、干预第4周后和干预第8周后对两组患者进行疼痛视觉模拟评分（visual analogue scale, VAS）评估、踝关节功能量表评分（American Orthopedic Foot and Ankle Score,AOFAS）和Y平衡测试（Y-balance test, YBT）评估。结果：治疗前,两组患者在评估的各项指标上无明显差异（P>0.05）。治疗8周后,两组患者在VAS疼痛评分上均有显著降低（P<0.05）,Y平衡测试综合数值得到显著改善（P<0.01）,AOFAS踝关节功能评分得到显著提高（P<0.05）。治疗后,试验组在上述各项评估指标中均显著优胜于对照组（P<0.05）。结论：为期8周的平衡训练和平衡训练联合按压MTrPs治疗均对FAI患者有显著的临床康复疗效,而平衡训练联合按压MTrPs治疗在缓解FAI患者的疼痛、促进踝关节功能和动态平衡的改善等方面具有更好的康复效益。     

The effect of manual pressure release on myofascial trigger points in the upper trapezius muscle

Sustained manual pressure has been advocated as effective treatment for myofascial trigger points (MTrPs). This study aimed to investigate the effect of manual pressure release (MPR) on the pressure sensitivity of latent MTrPs in the upper trapezius muscle using a novel pressure algometer. Subjects (N=37, mean age 23.1±3.2, M=12, F=23) were screened for the presence of latent MTrPs in the upper trapezius muscle (tender band that produced referred pain to the neck and/or head on manual pressure). Subjects were randomly allocated into either treatment (MPR) or control (sham myofascial release) groups. The pressure pain threshold (PPT) was recorded pre- and post-intervention using a digital algometer, consisting of a capacitance sensor attached to the tip of the palpating thumb. There was a significant increase in the mean PPT of MTrPs in the upper trapezius following MPR (P<0.001), but not following the sham treatment. Pressure was monitored and maintained during the application of MPR, and a reduction in perceived pain and significant increase in tolerance to treatment pressure (P<0.001) appeared to be caused by a change in tissue sensitivity, rather than an unintentional reduction of pressure by the examiner. The results suggest that MPR may be an effective therapy for MTrPs in the upper trapezius.     

基于电刺激的大鼠肌筋膜疼痛触发点的发生机制

目的:探究电刺激下肌筋膜疼痛触发点肌纤维的兴奋性和耐疲劳表现。方法:将48只雄性SD大鼠随机分为对照组(CG1、CG2、CG3)和触发点组(TG1、TG2、TG3)。CG1和TG1测试刺激阈值强度和最大收缩力量(MCF)以及其最适刺激强度;CG2和TG2测试不同刺激强度下MCF的变化;CG3和TG3测试不同刺激频率下MCF的变化。钝性打击结合离心运动造模8周,恢复4周后将大鼠接入生物机能测试系统,给予肌纤维一系列电刺激,测量比较各组引起肌肉收缩的阈值强度、MCF、刺激强度和频率诱导的肌肉疲劳等指标。结果:TG1组引起肌肉开始收缩的阈值强度和最大收缩力量(MCF)的最适刺激强度比CG1组低,具有显著性差异(P0.05);TG1组与CG1组的MCF无显著性差异(P0.05)。TG2组电刺激引起的MCF第15、20次增量电刺激低于第1、5、10次增量,具有高度显著性差异(P0.01);TG2组电刺激引起的MCF第10、15、20次增量CG2组,具有高度显著性差异(P0.01);TG2组电刺激引起的MCF第1、5、10次增量无显著性差异(P0.05);TG2组电刺激引起的MCF第1、5次增量与CG2组相比无显著性差异(P0.05)。TG3组电刺激引起MCF所需的刺激频率比CG3组低,呈高度显著性差异(P0.01);TG3组电刺激引起的MCF比CG3组低,具有显著性差异(P0.05)。结论:与正常肌纤维相比,触发点肌纤维对电刺激反应更敏感,受到连续电刺激时更易疲劳。     

The prevalence of latent myofascial trigger points and diagnostic criteria of the triceps surae and upper trapezius: a cross sectional study

Objectives

To determine the prevalence of latent myofascial trigger points (MTrPs), specific diagnostic criteria and the association between gender and MTrP prevalence in the triceps surae and upper trapezius.

Design

Cross-sectional study.

Setting

University, Faculty of Health and Life Sciences.

Participants

Two hundred and twenty healthy volunteers (132 females and 88 males; mean age 29.7 (SD 11.0).

Interventions

Not applicable.

Main outcome measures

Prevalence of latent MTrPs in the triceps surae and comparative upper trapezius; specific diagnostic criteria and pressure pain threshold (PPT).

Results

Latent MTrPs were prevalent in all triceps surae (range: 13 to 30%), left upper trapezius (23%) and right upper trapezius (20%). No MTrPs (0%) identified in the middle fibres of deltoid. For each specific diagnostic criterion, taut bands were most prevalent in the right gastrocnemius medial head (81%); tender spot in left gastrocnemius medial head (52%) and nodules in the right upper trapezius (35%). Local twitch response (0.5%), the least frequent diagnostic criterion was only found in the left gastocnemius medial head. A significant increase in latent MTrP prevalence for females compared to males in five of the six triceps surae MTrP sites, with no significant association for gender and latent MTrP prevalence in the left or right upper trapezius.

Conclusions

This study established the prevalence of latent MTrPs, specific diagnostic criteria and baseline normative data in the triceps surae. The middle fibres of deltoid were identified as a potential MTrP control site for future clinical research in the upper limb.     

Remote Influences of Acupuncture on the Pain Intensity and the Amplitude Changes of Endplate Noise in the Myofascial Trigger Point of the Upper Trapezius Muscle

Chou L-W, Hsieh Y-L, Kao M-J, Hong C-Z. Remote influences of acupuncture on the pain intensity and the amplitude changes of endplate noise in the myofascial trigger point of the upper trapezius muscle.

Objective

To investigate the remote effect of acupuncture on the pain intensity and the endplate noise (EPN) recorded from a myofascial trigger point (MTrP) of the upper trapezius muscle.

Design

Randomized controlled trial.

Setting

University hospital.

Participants

Patients (N=20) with active MTrPs in upper trapezius muscles and no experience in acupuncture therapy.

Interventions

Patients were divided into 2 groups. Those in the control group received sham acupuncture, and those in the acupuncture group received modified acupuncture therapy with needle insertion into multiple loci to elicit local twitch responses. The acupuncture points of Wai-guan and Qu-chi were treated.

Main Outcome Measures

Subjective pain intensity (numerical pain rating scale) and mean EPN amplitude in the MTrP of the upper trapezius muscle.

Results

The pain intensity in the MTrP was significantly reduced after remote acupuncture (from 7.4±0.8 to 3.3±1.1; P<.001), but not after sham acupuncture (from 7.4±0.8 to 7.1±0.9; P>.05). The mean EPN amplitude was significantly lower than the pretreatment level after acupuncture treatment (from 21.3±9.5μV to 9.5±3.5μV; P<.01), but not after sham acupuncture treatment (from 19.6±7.6μV to 19.3±7.8μV; P>.05). The change in the pain intensity was significantly correlated with the change of EPN amplitude (r = 0.685).

Conclusions

Both subjective changes in the pain intensity and objective changes of the EPN amplitude in the MTrP region of the upper trapezius muscle were found during and after acupuncture treatment at the remote ipsilateral acupuncture points. This study may further clarify the physiological basis of the remote effectiveness of acupuncture therapy for pain control.     

Instrument-assisted soft tissue mobilization increases myofascial trigger point pain threshold

Background

A myofascial trigger point (MTrP) has been defined as a hyperirritable, palpable nodule in a skeletal muscle. The signs and symptoms of a MTrP include muscle pain, weakness, and dysfunction. MTrPs are common problems associated with soft tissue pathology. Having an intervention to decrease MTrP pain can be clinically valuable.

Uncovering the biochemical milieu of myofascial trigger points using in vivo microdialysis: An application of muscle pain concepts to myofascial pain syndrome

This article discusses muscle pain concepts in the context of myofascial pain syndrome (MPS) and summarizes microdialysis studies that have surveyed the biochemical basis of this musculoskeletal pain condition. Though MPS is a common type of non-articular pain, its pathophysiology is only beginning to be understood due to its enormous complexity. MPS is characterized by the presence of myofascial trigger points (MTrPs), which are defined as hyperirritable nodules located within a taut band of skeletal muscle. MTrPs may be active (spontaneously painful and symptomatic) or latent (non-spontaneously painful). Painful MTrPs activate muscle nociceptors that, upon sustained noxious stimulation, initiate motor and sensory changes in the peripheral and central nervous systems. This process is called sensitization. In order to investigate the peripheral factors that influence the sensitization process, a microdialysis technique was developed to quantitatively measure the biochemical milieu of skeletal muscle. Biochemical differences were found between active and latent MTrPs, as well as in comparison with healthy muscle tissue. In this paper we relate the findings of elevated levels of sensitizing substances within painful muscle to the current theoretical framework of muscle pain and MTrP development.     

Trigger points and myofascial pain: toward understanding how they affect headaches

Myofascial pain, referred from hyperalgesic trigger points located in skeletal muscle and its associated fascia, is a common cause of persistent regional pain. Clinical and experimental literature on manifestations, pathophysiology, and management of pain from myofascial trigger points is reviewed with priority given to how pain referred from trigger points generates, triggers, and maintains headaches—especially chronic and recurrent ones. Because treating myofascial problems may be the only way to offer complete relief from certain types of headache, clinicians must learn to diagnose and manage trigger points in neck, shoulder, and head muscles.     

Novel Applications of Ultrasound Technology to Visualize and Characterize Myofascial Trigger Points and Surrounding Soft Tissue

Sikdar S, Shah JP, Gebreab T, Yen R-H, Gilliams E, Danoff J, Gerber LH. Novel applications of ultrasound technology to visualize and characterize myofascial trigger points and surrounding soft tissue.

Objective

To apply ultrasound (US) imaging techniques to better describe the characteristics of myofascial trigger points (MTrPs) and the immediately adjacent soft tissue.

Design

Four sites in each patient were labeled based on physical examination as active myofascial trigger points (A-MTrPs; spontaneously painful), latent myofascial trigger points (L-MTrPs; nonpainful), or normal myofascial tissue. US examination was performed on each subject by a team blinded to the physical findings. A 12∼5MHz US transducer was used. Vibration sonoelastography (VSE) was performed by color Doppler variance imaging while simultaneously inducing vibrations (∼92Hz) with a handheld massage vibrator. Each site was assigned a tissue imaging score as follows: 0, uniform echogenicity and stiffness; 1, focal hypoechoic region with stiff nodule; 2, multiple hypoechoic regions with stiff nodules. Blood flow in the neighborhood of MTrPs was assessed using Doppler imaging. Each site was assigned a blood flow waveform score as follows: 0, normal arterial flow in muscle; 1, elevated diastolic flow; 2, high-resistance flow waveform with retrograde diastolic flow.

Setting

Biomedical research center.

Participants

Subjects (N=9) meeting Travell and Simons' criteria for MTrPs in a taut band in the upper trapezius.

Interventions

Not applicable.

Main Outcome Measures

MTrPs were evaluated by (1) physical examination, (2) pressure algometry, and (3) three types of US imaging including gray-scale (2-dimensional [2D] US), VSE, and Doppler.

Results

MTrPs appeared as focal, hypoechoic regions on 2D US, indicating local changes in tissue echogenicity, and as focal regions of reduced vibration amplitude on VSE, indicating a localized, stiff nodule. MTrPs were elliptical, with a size of .16±.11cm². There were no significant differences in size between A-MTrPs and L-MTrPs. Sites containing MTrPs were more likely to have a higher tissue imaging score compared with normal myofascial tissue (P<.002). Small arteries (or enlarged arterioles) near A-MTrPs showed retrograde flow in diastole, indicating a highly resistive vascular bed. A-MTrP sites were more likely to have a higher blood flow score compared with L-MTrPs (P<.021).

Conclusions

Preliminary findings show that, under the conditions of this investigation, US imaging techniques can be used to distinguish myofascial tissue containing MTrPs from normal myofascial tissue (lacking trigger points). US enables visualization and some characterization of MTrPs and adjacent soft tissue.