Documentation of myofascial trigger points

Two basic diagnostic features of myofascial trigger points (TPs), namely, local tenderness and alteration of tissue consistency (such as in taut bands, muscle spasm), can be documented quantitatively by simple hand-held instruments. A pressure threshold meter (algometer) assists in location of TPs and their relative sensitivity. A side-to-side difference exceeding 2kg in comparison with normal values indicates pathologic tenderness. The effect of treatment can be quantified. Pressure tolerance, measured over normal muscles and shin bones, expresses pain sensitivity. Myopathy is suspected if muscle tolerance drops below bone tolerance. Tissue compliance measurement documents objectively and quantitatively alteration in soft tissue consistency. Muscle spasm, tension, spasticity, taut bands, scar tissues, or fibrositic nodules can be documented. The universal clinical dynamometer is used as part of a physical examination to quantify weakness. Thermography (heat imaging) demonstrates discoid shaped hot spots over TPs. Muscle activity, spasm, or contraction is visualized as increased heat emission in the shape of the active muscle.     

实时组织弹性成像指导针刺激痛点治疗肌筋膜疼痛的疗效初探

目的应用实时组织弹性成像(RTE)确定肌筋膜激痛点(MTrPs),探讨其引导针刺治疗肌筋膜疼痛综合征(MPS)的应用价值。方法选择我院斜方肌MPS患者60例,按随机数字表法分为RTE组和传统针刺组各30例,比较两组患者治疗前后MTrPs弹性评分、疼痛评分的差异。对患者随访1年,比较两组患者的治疗效果及远期预后。结果两组治疗后MTrPs的弹性评分比较,差异有统计学意义(P<0.05)。RTE组治疗后视觉模拟评分(VAS)和疼痛评定指数(PRI)分别为(3.02±0.54)分、(3.34±0.62)分,均明显低于传统针刺组(3.89±0.36)分、(3.76±0.34)分,差异均有统计学意义(均P<0.05)。随访结果显示,RTE组的显效率为86.7%,累计无复发率为93.3%,传统针刺组的显效率为60.0%,累计无复发率为57.1%,两组比较差异均有统计学意义(均P<0.05)。结论RTE指导针刺MTrPs治疗MPS的疗效及预后均明显优于传统触诊法针刺,具有重要的临床价值。     

Thermographic imaging of myofascial trigger points

Thermographic findings in two patients suffering from myofascial trigger points are presented. These are shown as discrete foci of increased thermal emission, with corresponding areas of diffuse hyperthermia. These thermal findings correlate highly with the classic locations of specific trigger points and their areas of pain referral, respectively, as described in literature. Not only do these cases describe a thermal pattern that varies somewhat from previous reports, but they also illustrate the previously unreported imaging of areas of pain referral from specific trigger points.     

Understanding effective treatments of myofascial trigger points

This article considers specific treatment approaches and the role of etiological mechanisms in terms of clinical feature characteristics of MTrPs: increased muscle tension, pain and tenderness, painful stretch range of motion, initiating causes of MTrPs. Final sections note additional treatments that are currently used, and summarize the etiological and clinical distinctions between MTrPs and fibromyalgia.     

Acupuncture-like versus conventional transcutaneous electrical nerve stimulation in the management of active myofascial trigger points: A randomized controlled trial

PurposeMyofascial pain syndrome (MPS) is one of the most common causes of chronic musculoskeletal pain. The transcutaneous electrical nerve stimulation (TENS) is a non-expensive, safe, feasible modality, used recently for the treatment of MPS with promising but limited results. The purpose of this study was to determine the efficacy of acupuncture-like TENS (AL-TENS) vs conventional TENS (C-TENS) in the treatment of active myofascial trigger points.MethodsThis randomized controlled trial study was carried out with 60 consecutive patients with active trapezius trigger points referred to Physical Medicine and Rehabilitation Clinic. Participants randomly assigned to receive AL-TENS, C-TENS or sham TENS (S-TENS). The Visual Analogue Scale (VAS), Pressure Pain Thresholds (PPTs), and neck range of motion (ROM) were measured at baseline, after the first treatment sessions, after the final treatment session, and 3 months after the end of the last treatment session. Patients function was evaluated by Disabilities of the Arm, Shoulder, and Hand (DASH) at baseline, after the final treatment sessions, and 3 months after the end of intervention.ResultsThe interaction effect of time and group was significantly different when evaluating VAS (df = 4.65, F = 2.50, p = 0.038) and DASH (df = 2.63, F = 7.25, p < 0.001) in favor of active groups, as well as neck total lateral bending in favor of AL-TENS group compared other two groups (df = 4.16, F = 5.23, p = 0.001). Both VAS and DASH improved significantly at all follow-ups in AL-TENS and C-TENS groups. Of note, significant immediate improvement in all outcomes was observed only with AL-TENS.ConclusionsAccording to the present study, both AL-TENS and C-TENS were superior to placebo in pain reduction and functional improvement. Although both TENS techniques have similar efficiency on pain reduction, functional and pain perception improvement, the AL-TENS was the superior approach when evaluating neck lateral bending ROM.     

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。     

Traditional Chinese Medicine acupuncture and myofascial trigger needling: The same stimulation points?

BackgroundAcupuncture originates in China, and its effectiveness has been well documented in musculoskeletal pain disorders and other conditions. A widely accepted contemporary medical treatment option for myofascial pain is trigger point needling. Although there are many differences between Traditional Chinese Medicine acupuncture theory and the myofascial trigger point needling framework, it is argued that the stimulation sites for these two needling modalities are similar.DiscussionIn this paper we examined the correspondence between Traditional Chinese Medicine acupoints and myofascial trigger points. Based on this correspondence, we considered exploration of Ah-shi points from four aspects: pain recognition, distal Ah-shi points, Anti-Ah-shi points, and management approaches.Summary: The extent of correspondence is influenced by definitions of acupoints. Myofascial trigger points are significantly correlated to Traditional Chinese Medicine acupoints, including primary channel acupoints, extra acupoints, and Ah-shi points. Considering the correlation between MTrPs and acupoints and the rarely-studied research area of Ah-shi points, it may be reasonable to incorporate research findings of myofascial trigger points into further investigations into Ah-shi points. Correspondence between myofascial trigger points and acupoints enhances contemporary understanding of the mechanism of action of acupuncture, and may serve to facilitate increased integration of acupuncture into clinical management.     

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.     

Contribution of myofascial trigger points to migraine symptoms.

This study evaluated the contribution of myofascial trigger points (TrPs) to migraine pain. Seventy-eight migraine patients with cervical active TrPs whose referred areas (RAs) coincided with migraine sites (frontal/temporal) underwent electrical pain threshold measurement in skin, subcutis, and muscle in TrPs and RAs at baseline and after 3, 10, 30, and 60 days; migraine pain assessment (number and intensity of attacks) for 60 days before and 60 days after study start. Fifty-four patients (group 1) underwent TrP anesthetic infiltration on the 3rd, 10th, 30th, and 60th day (after threshold measurement); 24 (group 2) received no treatment. Twenty normal subjects underwent threshold measurements in the same sites and time points as patients. At baseline, all patients showed lower than normal thresholds in TrPs and RAs in all tissues (P < .001). During treatment in group 1, all thresholds increased progressively in TrPs and RAs (P < .0001), with sensory normalization of skin/subcutis in RAs at the end of treatment; migraine pain decreased (P < .001). Threshold increase in RAs and migraine reduction correlated linearly (.0001 < P < .006). In group 2 and normal subjects, no changes occurred. Cervical TrPs with referred areas in migraine sites thus contribute substantially to migraine symptoms, the peripheral nociceptive input from TrPs probably enhancing the sensitization level of central sensory neurons. PERSPECTIVE: This article shows the beneficial effects of local therapy of active myofascial trigger points (TrPs) on migraine symptoms in patients in whom migraine sites coincide with the referred areas of the TrPs. These results suggest that migraine pain is often contributed to by myofascial inputs that enhance the level of central neuronal excitability.     

New views of myofascial trigger points: etiology and diagnosis

Simons DG. New views of myofascial trigger points: etiology and diagnosis.Two studies appearing in Archives, one by Shah and colleagues and another one by Chen and colleagues, present groundbreaking findings that can reduce some of the controversy surrounding myofascial trigger points (MTPs). Both author groups recognize the ubiquity of this disease and the importance to patients of health care professionals becoming better acquainted with the cause and identification of MTPs. The integrated hypothesis is the most credible and most complete proposed etiology of MTPs. However, the feedback loop suggested in this hypothesis has a few weak links, and studies by Shah and colleagues in particular supply a solid link for one of them. The feedback loop connects the hypothesized energy crisis with the milieu changes responsible for noxious stimulation of local nociceptors that causes the local and referred pain of MTPs. Shah’s reports quantify the presence of not just 1 noxious stimulant but 11 of them with outstanding concentrations of immune system histochemicals. The results also strongly place a solid histochemical base under the important clinical distinction between active and latent MTPs. The study by Chen on the use of magnetic resonance elastography (MRE) imaging of the taut band of an MTP in an upper trapezius muscle may open a whole new chapter in the centuries-old search for a convincing demonstration of the cause of MTP symptoms. MRE is a modification of existing magnetic resonance imaging equipment, and it images stress produced by adjacent tissues with different degrees of tension. This report seems to present an MRE image of the taut band that shows the chevron signature of the increased tension of the taut band compared with surrounding tissues.     

Intramuscular and nerve root stimulation vs lidocaine injection to trigger points in myofascial pain syndrome.

OBJECTIVES: To compare the efficacies of an intramuscular stimulation technique and 0.5% lidocaine injection to trigger points in myofascial pain syndrome. PARTICIPANTS: Forty-three people with myofascial pain syndrome of the upper trapezius muscle. INTERVENTIONS: Twenty-two subjects were treated with intramuscular stimulation and another 21 with 0.5% lidocaine injection at all the trigger points on days 0, 7 and 14. RESULTS: Intramuscular stimulation resulted in a significant reduction in Wong-Baker FACES pain scale scores at all visits and was more effective than trigger point injection. Intramuscular stimulation also resulted in significant improvement on the Geriatric Depression Scale - Short Form. Local twitch responses occurred in 97.7% (42/43) of patients. All the passive cervical ranges of motion were significantly increased. Post-treatment soreness was noted in 54.6% of patients in the intramuscular stimulation group and 38.1% in the trigger point injection group, respectively, and gross subcutaneous haemorrhage (> 4 cm2) was seen in only one patient in the trigger point injection group. CONCLUSION: In managing myofascial pain syndrome, after one month intramuscular stimulation resulted in more significant improvements in pain intensity, cervical range of motion and depression scales than did 0.5% lidocaine injection of trigger points. Intramuscular stimulation is therefore recommended for myofascial pain syndrome.     

Spatial pain propagation over time following painful glutamate activation of latent myofascial trigger points in humans

The aim of this present study was to test the hypothesis that tonic nociceptive stimulation of latent myofascial trigger points (MTPs) may induce a spatially enlarged area of pressure pain hyperalgesia. Painful glutamate (.2 mL, 1M) stimulation of latent MTPs and non-MTPs in the forearm was achieved by an electromyography-guided procedure. Pain intensity (as rated on the visual analog scale [VAS]) and referred pain area following glutamate injections were recorded. Pressure pain threshold (PPT) was measured over 12 points in the forearm muscles and at the mid-point of tibialis anterior muscle before and at .5 hour, 1 hour, and 24 hours after glutamate injections. The results showed that maximal pain intensity, the area under the VAS curve, and referred pain area were significantly higher and larger following glutamate injection into latent MTPs than non-MTPs (all, P < .05). A significantly lower PPT level was detected over time after glutamate injection into latent MTPs at .5 hour (at 4 points), 1 hour (at 7 points), and 24 hours (at 6 points) in the forearm muscles. However, a significantly lower PPT was observed only at 24 hours after glutamate injection into non-MTPs in the forearm muscles (at 4 points, P < .05) when compared to the pre-injection PPT. PPT at the mid-point of the tibialis anterior was significantly decreased at 1 hour only as compared to the pre-injection PPT in both groups (< .05). The results of the present study indicate that nociceptive stimulation of latent MTPs is associated with an early onset of locally enlarged area of mechanical hyperalgesia. PERSPECTIVE: This study shows that MTPs are associated with an early occurrence of a locally enlarged area of pressure hyperalgesia associated with spreading central sensitization. Inactivation of MTPs may prevent spatial pain propagation.     

Brain manifestation and modulation of pain from myofascial trigger points

The brain plays a prominent role in the generation and modulation of pain. It contains powerful endogenous pain modulatory systems that can be engaged in a beneficial way by therapeutical intervention. In contrast, pain chronification is associated with maladaptive structural and functional changes that may shift the balance of the modulatory systems. Although pain from myofascial trigger points (MTrPs) is highly prevalent, little is known about its brain manifestations and modulation. Recent neuroimaging data suggest that hyperalgesia from MTrPs is processed in similar regions as hyperalgesia from other pain conditions. However, abnormal hippocampal hypoactivity suggests that dysfunctional stress responses may play an important role in the generation and maintenance of hyperalgesia from MTrPs. Other data suggest that short-term pain relief obtained with intramuscular electrostimulation within an MTrP is partially due to descending pain inhibitory mechanisms.     

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.     

肩周筋膜炎的触发点针刺效应

目的：通过对肩周肌筋膜炎的患者进行触发点针刺治疗，以观察其临床效果。方法：选择2002—04／2004—10玉溪市人民医院骨科门诊治疗的肩关节周围炎（简称肩周炎）患者30例。肩关节前屈、外展受限。应用10g／L利多卡因注射液对肩周的三角肌、肱二头肌痛点进行针刺治疗，每隔7～12d1次，治疗两三次。并进行三角肌、肱二头肌的牵张锻炼，3次／d。治疗后3个月采用自拟评分对患者疼痛和肩关节活动度进行评定（共为8分，1分为无痛，8分为受累肌疼痛较重，整个肩关节活动受限，夜痛）。结果：按意向处理分析，30例患者均进入结果分析。①患者疼痛评分：治疗后3个月疼痛评分明显低于治疗前[（1．40&;#177;0.67），（5．90&;#177;0．99）分，t=48．7，P〈0．01]。②患者肩关爷活动度：治疗后平均外展、前屈角度明显大于治疗前治疗前（113．4&;#176;比46.3&;#176;，98.4&;#176;比33．5&;#176;）。结论：针剌治疗肩周肌筋膜炎能够明显地减轻疼痛，改善因其引起的肩关节活动障碍。     

肩周筋膜炎的触发点针刺效应

目的:通过对肩周肌筋膜炎的患者进行触发点针刺治疗,以观察其临床效果。方法:选择2002-04/2004-10玉溪市人民医院骨科门诊治疗的肩关节周围炎(简称肩周炎)患者30例。肩关节前屈、外展受限。应用10g/L利多卡因注射液对肩周的三角肌、肱二头肌痛点进行针刺治疗,每隔7～12d1次,治疗两三次。并进行三角肌、肱二头肌的牵张锻炼,3次/d。治疗后3个月采用自拟评分对患者疼痛和肩关节活动度进行评定(共为8分,1分为无痛,8分为受累肌疼痛较重,整个肩关节活动受限,夜痛)。结果:按意向处理分析,30例患者均进入结果分析。①患者疼痛评分:治疗后3个月疼痛评分明显低于治疗前[(1.40±0.67),(5.90±0.99)分,t=48.7,P<0.01]。②患者肩关节活动度:治疗后平均外展、前屈角度明显大于治疗前治疗前(113.4°比46.3°,98.4°比33.5°)。结论:针刺治疗肩周肌筋膜炎能够明显地减轻疼痛,改善因其引起的肩关节活动障碍。