Relationship between muscle spindles and myofascial trigger spots according to Hoffmann reflex pathway and tissue morphology characteristics in a rat model

2020 ◽  
Vol 38 (2) ◽  
pp. 109-116
Author(s):  
Lin Liu ◽  
Qiang-Min Huang ◽  
Qing-Guang Liu ◽  
Thi-Tham Nguyen ◽  
Jian-Qin Yan ◽  
...  
Keyword(s):  
Muscle Spindles ◽  
Trigger Points ◽  
H Reflex ◽  
Hoffmann Reflex ◽  
Sprague Dawley ◽  
Morphological Examination ◽  
Myoelectrical Activity ◽  
Myofascial Trigger Points ◽  
Anatomical Relationship ◽  
And Control

Objectives: To determine how muscle spindles are involved in the pathophysiology of chronic myofascial trigger spots (MTrSs, similar to myofascial trigger points) in a rat injury model according to the characteristics of the Hoffmann reflex (H-reflex) and the anatomical relationship between muscle spindles and MTrSs. Methods: 16 male Sprague-Dawley rats (7 weeks old) were randomly divided into experimental and control groups. A blunt strike injury and eccentric exercise were applied to the gastrocnemius muscle of rats in the experimental group once a week for 8 weeks as a MTrS modelling intervention. Subsequently, the rats were reared normally and rested for 4 weeks. At the end of the 12th week, the rats were examined for the presence of MTrSs defined by the detection of a palpable taut band exhibiting both a local twitch response and spontaneous electrical activity. After modelling, evocation of the H-reflex and morphological examination of muscle spindles and MTrSs were conducted. Results: The threshold (0.35±0.04 mA) of the H-reflex and latency (1.24±0.18 ms) of the M wave recorded at MTrSs were not significantly different to those at non-MTrSs (P>0.05). Compared with non-MTrSs, a lower Mmax (4.28±1.27 mV), higher Hmax (median (IQR) 0.95 (0.80–1.08) mV) and Hmax/Mmax (median (IQR) 0.21 (0.16–0.40)), and shorter H wave latency (4.60±0.89 ms) were recorded at MTrSs (P<0.05). Morphologically, there was a close anatomical relationship between the MTrS cells and the muscle spindles. Discussion: Compared with normal muscles, the H-reflex myoelectrical activity was enhanced and some muscle spindles might have been influenced by active MTrSs. Thus, muscle spindles may play an important role in the pathological mechanism underlying myofascial trigger points.

scholarly journals Acupotomy Alleviates Energy Crisis at Rat Myofascial Trigger Points

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yi Zhang ◽  
Ning-Yu Du ◽  
Chen Chen ◽  
Tong Wang ◽  
Li-Juan Wang ◽  
...  
Keyword(s):  
High Performance ◽  
Trigger Points ◽  
Control Group ◽  
Model Group ◽  
Sprague Dawley ◽  
Myofascial Trigger Points ◽  
Sprague Dawley Rats ◽  
Lower Treatment ◽  
Lidocaine Injection ◽  
Mechanical Pain Thresholds

The aim of this study was to determine the effects of acupotomy on energy crises in rat trigger points (TrPs) by measuring mechanical pain thresholds (MPTs) and levels of acetylcholinesterase (AChE), free sarcoplasmic calcium (Ca2+), adenosine 5′-triphosphate (ATP), adenosine 5′-monophosphate (AMP), substance P (SP), and calcitonin gene-related peptide (CGRP) in rat muscle TrP tissue. Male Sprague Dawley rats (n = 32) were randomly divided into four groups: control, TrP, acupotomy, and lidocaine injection. Enzyme-linked immunosorbent assays were used to measure AChE, and free sarcoplasmic Ca2+ concentrations were determined by fluorescent staining with Fura-2 AM; high-performance liquid chromatography was used to measure ATP and AMP, and SP and CGRP were evaluated by immunohistochemistry. Compared with the control group, free sarcoplasmic Ca2+, AMP, SP, and CGRP were higher in the model group, while MPT, AChE, and ATP were lower. Treatment with acupotomy or lidocaine injection reduced free sarcoplasmic Ca2+, SP, and CGRP and increased MPTs and AChE levels compared with the model group. However, only acupotomy also led to decreased AMP and increased ATP levels relative to the model group. We conclude that acupotomy can alleviate energy crises at TrPs.

scholarly journals Histopathological Nature of Myofascial Trigger Points at Different Stages of Recovery from Injury in a Rat Model

2017 ◽  
Vol 35 (6) ◽  
pp. 445-451 ◽  
Author(s):  
Hui Zhang ◽  
Jiao-Jiao Lü ◽  
Qiang-Min Huang ◽  
Lin Liu ◽  
Qing-Guang Liu ◽  
...  
Keyword(s):  
Rat Model ◽  
Large Diameter ◽  
Trigger Points ◽  
Control Group ◽  
Sprague Dawley ◽  
Myofascial Trigger Points ◽  
Sprague Dawley Rats ◽  
Longitudinal View ◽  
Recovery Times ◽  
Electron Microscopes

Objective To investigate the histopathological nature of myofascial trigger points (MTrPs) or spots (MTrSs) at different stages of recovery from injury in a rat model. Methods Forty Sprague–Dawley rats were randomly divided into two groups: a control group (CG) and experimental group (EG). The CG was further randomly subdivided into CG1 and CG2 subgroups. The CG2 was used for palpating the taut band and CG1 as a blank. EG was subdivided into three groups according to recovery times: 4 weeks (4W), 8 weeks (8W) and 12 weeks (12W); these groups consisted of eight rats each. All CG rats received no intervention, whereas the intervention in EG rats was by a blunt strike to the vastus medialis and eccentric exercise for 8 weeks. The taut bands with spontaneous electrical activity were then detected in the muscle to guide a muscle biopsy. The histopathological findings were investigated under optical and electron microscopes in all groups. Results Under optical microscopy, the differently augmented sizes of round fibres (contracture knots) with deep staining in the transverse section and fusiform shapes in a longitudinal view were clearly seen in CG2 and EGs with a large diameter; the number of contracture knots was significantly more in EGs than in CGs. Under an electron microscope, the mitochondria in EGs significantly decreased with abnormal structures. The sarcomeres were significantly shortened in the 8W and 12W EGs. Conclusion An injury can cause activation of MTrSs in a muscle and an activated level of MTrPs depending on the number of contracture knots in muscle with impaired energy production.

scholarly journals Percutaneous Application of Galvanic Current in Rodents Reverses Signs of Myofascial Trigger Points

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
R. Margalef ◽  
M. Bosque ◽  
P. Monclús ◽  
P. Flores ◽  
F. Minaya-Muñoz ◽  
...  
Keyword(s):  
Animal Model ◽  
Electric Fields ◽  
Electrical Current ◽  
Trigger Points ◽  
Sprague Dawley ◽  
Galvanic Current ◽  
Myofascial Trigger Points ◽  
Sprague Dawley Rats ◽  
Release Of Acetylcholine ◽  
Miniature Endplate Potentials

An increase in the spontaneous release of acetylcholine (ACh) at the motor endplate is directly related to the generation of myofascial trigger points (MTrPs). In this study, percutaneous electric fields were applied to an animal model of MTrPs with high levels of spontaneous ACh release. All experiments were performed on Swiss mice and Sprague Dawley rats. For evaluating the spontaneous neurotransmission, intracellular recordings were performed, and the frequency of miniature endplate potentials was evaluated. Electromyographic recordings were also conducted to evaluate the endplate noise. Finally, the number and strength of local twitch responses (LTR) were evaluated using ultrasound recordings. The protocols used for the electric currents were 0.4 mA for five seconds and four repetitions (protocol 1), 1.5 mA for five seconds and three repetitions (protocol 2), and 3 mA for three seconds and three repetitions (protocol 3). After a subcutaneous injection of neostigmine (NTG), a great increase was observed in the frequency of mEPPs, together with an elevated endplate noise. Protocols 2 and 3 were the most effective. Protocol 3 could completely reverse the action of NTG at both three hours and 24 hours, respectively. The application of percutaneous currents produced both an increase in the number (144%) and in the speed (230% faster) of LTR compared with dry needling. In conclusion, higher doses of electrical current are more effective for decreasing MTrPs findings in an animal model.

scholarly journals Tensiomyography, sonoelastography, and mechanosensitivity differences between active, latent, and control low back myofascial trigger points

Medicine ◽  
2017 ◽  
Vol 96 (10) ◽  
pp. e6287 ◽  
Author(s):  
César Calvo-Lobo ◽  
Ignacio Diez-Vega ◽  
Beatriz Martínez-Pascual ◽  
Silvia Fernández-Martínez ◽  
Mónica de la Cueva-Reguera ◽  
...  
Keyword(s):  
Trigger Points ◽  
Low Back ◽  
Myofascial Trigger Points ◽  
And Control

Myoelectrical Activity and Muscle Morphology in a Rat Model of Myofascial Trigger Points Induced by Blunt Trauma to the Vastus Medialis

2013 ◽  
Vol 31 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Qiang-Min Huang ◽  
Gang Ye ◽  
Zhen-Yan Zhao ◽  
Jiao-Jiao Lv ◽  
Li Tang
Keyword(s):  
Trigger Points ◽  
Control Group ◽  
Muscle Fibres ◽  
Vastus Medialis ◽  
Myoelectrical Activity ◽  
Muscle Morphology ◽  
Myofascial Trigger Points ◽  
External Stimulation ◽  
Group A ◽  
Group B

Objectives To explore myoelectrical activity and muscle morphology of myofascial trigger points (MTrPs) in an injury model of rats. Methods A total of 24 male SD rats were randomly divided into a control group (group A) and model group (group B). A blunt striking injury and eccentric exercise were applied to the vastus medialis (VM) of rats in group B for 8 weeks. Later, the palpable taut band (TB), local twitch response, myoelectrical activities and morphology in the two groups were examined. Results An average of 2.5 (30/12) palpable TBs were detected in the VM in group B compared with none in group A. The MTrPs had two types of abnormal potential. Their amplitudes were significantly higher than those in the control group (p<0.01) but their durations showed no significant differences. A series of reflex contractions appeared in groups A and B in response to external stimulation to the ear. Their amplitude and duration in group B were significantly lower than those in group A. A series of lower fibrillation potentials repeatedly occurred in model MTrPs in group B. The morphology of MTrPs showed abnormal muscle fibres with large round or ellipse shapes in cross-section and enlarged tapering shapes in longitudinal section. Conclusions Active MTrPs can be provoked by repeated blunt injury. Active MTrPs are a group of muscle fibres with abnormal shapes and abnormal myoelectrical potentials. External stimulation provokes low-voltage responses in MTrPs, which is different from the response of normal muscle fibres.

Increased H-Reflex Response Induced by Intramuscular Electrical Stimulation of Latent Myofascial Trigger Points

2009 ◽  
Vol 27 (4) ◽  
pp. 150-154 ◽  
Author(s):  
Hong-You Ge ◽  
Mariano Serrao ◽  
Ole K Andersen ◽  
Thomas Graven-Nielsen ◽  
Lars Arendt-Nielsen
Keyword(s):  
Electrical Stimulation ◽  
Conduction Velocity ◽  
Tibial Nerve ◽  
Trigger Points ◽  
H Reflex ◽  
Reflex Response ◽  
Muscle Spindle Afferents ◽  
Myofascial Trigger Points ◽  
Reflex Threshold ◽  
Stimulation Of

Background Myofascial trigger points (MTrPs) present with mechanical hyperalgesia and allodynia. No electrophysiological evidence exists as to the excitability of muscle spindle afferents at myofascial trigger points MTrPs. The purpose of this current study was to explore whether an H-reflex response could be elicited from intramuscular electrical stimulation. If so, to assess the possibility of increased reflex response at MTrPs. Methods The H-reflex latency and the conduction velocity were first determined from electrical stimulation of the tibial nerve in 13 healthy subjects. Then an intramuscular monopolar needle electrode was inserted randomly into a latent MTrP or a non-MTrP in the gastrocnemius muscle. Electrical stimuli at different intensities were delivered via the intramuscular recording electrode to the MTrP or non-MTrP. Results The average conduction velocity (44.3 ± 1.5 m/s) of the electrical stimulation of tibial nerve was similar (p>0.05) with the conduction velocity (43.9 ± 1.4 m/s) of intramuscular electrical stimulation. The intramuscular H-reflex at MTrPs was higher in amplitude than non-MTrPs (p<0.001). The reflex threshold was lower for MTrPs than non-MTrPs (p<0.001). Conclusion The current study provides first electrophysiological evidence that intramuscular electrical stimulation can evoke H-reflex, and that higher H-reflex amplitude and lower H-reflex threshold exist at MTrPs than non-MTrPs respectively, suggesting that muscle spindle afferents may be involved in the pathophysiology of MTrPs.

Repeated Electrical Point Stimulation (EPS) Treatments for Myofascial Trigger Points in the Upper Trapezius Muscle

2020 ◽  
pp. 1-6
Author(s):  
Blaine C. Long
Keyword(s):  
Pain Perception ◽  
Treatment Time ◽  
Trigger Point ◽  
Pressure Pain Threshold ◽  
Trapezius Muscle ◽  
Trigger Points ◽  
Myofascial Trigger Points ◽  
Upper Trapezius ◽  
Control Pain ◽  
And Control

Electrical point stimulation (EPS) is suggested to decrease myofascial trigger point (MTrP) pain without influencing pressure pain threshold (PPT) following one treatment. The purpose of this study was to determine if repeated EPS treatments decrease pain perception or PPT. EPS decreased pain immediately following and 10 min following (p < .05) application. For those receiving EPS, pretreatment pain on day 1 was greater than pre- and posttreatments on days 2, 3, 4, 5, and 6 (p < .05). Patients receiving EPS experienced less pain than placebo and control. Pain did not change for placebo or control (p > .05). PPT did not change for treatment, time, or day (p > .07).

scholarly journals Assessment of the effects of ischaemia/ hypoxia on angiogenesis in rat myofascial trigger points using colour Doppler flow imaging

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10481
Author(s):  
Fangyan Jiang ◽  
Shuangcheng Yu ◽  
Haiqing Su ◽  
Shangyong Zhu
Keyword(s):  
Blood Flow ◽  
Myofascial Pain ◽  
Trigger Points ◽  
Control Group ◽  
Flow Imaging ◽  
Sprague Dawley ◽  
Colour Doppler ◽  
Myofascial Trigger Points ◽  
Doppler Flow ◽  
Hypoxic Conditions

Background & Aims Myofascial pain syndrome (MPS) is a common non-articular disorder of the musculoskeletal system that is characterized by the presence of myofascial trigger points (MTrPs). Despite the high prevalence of MPS, its pathogenesis, which induces the onset and maintenance of MTrPs, is still not completely understood. To date, no studies have investigated the changes in the biochemical milieu caused by ischaemia/hypoxia in the MTrP regions of muscle that are proposed in the integrated hypothesis. Therefore, this study investigated whether ischaemic/hypoxic conditions participate in the formation of active MTrPs and affect angiogenesis using colour Doppler flow imaging (CDFI). Methods Twenty-five Sprague-Dawley rats were randomly divided into a model group and a normal control group. A model of active MTrPs was established by a blunt strike combined with eccentric exercise. Enzyme-linked immunosorbent assays (ELISAs) were employed to detect the levels of HIF-1α and VEGF. Microvessel density (MVD) was evaluated using immunohistochemistry. CDFI was applied to observe the blood flow signals in the MTrPs, which were classified into four grades based on their strengths. Results Compared with the control group, the active MTrP group exhibited significantly higher HIF-1α and VEGF levels and MVD values. These differences were accompanied by increased blood flow signals. In the active MTrP group, the blood flow signal grade was positively correlated with the MVD (P < 0.05) and independently correlated with the VEGF level (P < 0.05) but was not correlated with the expression of HIF-1α (P > 0.05). Conclusion Ischaemic/hypoxic conditions may be involved in the formation of MTrPs. CDFI is useful for detection of the features of angiogenesis in or surrounding MTrPs via assessment of blood flow signals.

Tanshinone IIA attenuates elastase-induced AAA in rats via inhibition of MyD88-dependent TLR-4 signaling

VASA ◽  
2014 ◽  
Vol 43 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Tao Shang ◽  
Feng Ran ◽  
Qian Qiao ◽  
Zhao Liu ◽  
Chang-Jian Liu
Keyword(s):  
Nuclear Factor Κb ◽  
Tanshinone Iia ◽  
Myeloid Differentiation ◽  
Aortic Tissue ◽  
Toll Like Receptor ◽  
Sprague Dawley ◽  
Toll Like Receptor 4 ◽  
Tissue Samples ◽  
Myeloid Differentiation Factor ◽  
And Control

Background: The purpose of this study was to determine whether myeloid differentiation factor88-dependent Toll-Like Receptor-4 (TLR-4) signaling contributed to the inhibition of abdominal aortic aneurysm (AAA) by Tanshinone IIA (Tan IIA). Materials and methods: Male Sprague-Dawley rats (n = 12 / group) were randomly distributed into three groups: Tan IIA, control, and sham. The rats from Tan IIA and control groups under-went intra-aortic elastase perfusion to induce AAAs, and those in the sham group were perfused with saline. Only the Tan IIA group received Tan IIA (2 mg / rat / d). Aortic tissue samples were harvested at 24 d after perfusion and evaluated using reverse transcriptase-polymerase chain reaction, Western blot, immunohistochemistry and immunofluorescence. Results: The over-expression of Toll-Like Receptor-4 (TLR-4), Myeloid Differentiation factor 88 (MyD88), Phosphorylated Nuclear Factor κB (pNF-κB) and Phosphorylated IκBα (pIκBα) induced by elastase perfusion were significantly decreased by Tan IIA treatment. Conclusions: Tan IIA attenuates elastase-induced AAA in rats possibly via the inhibition of MyD88-dependent TLR-4 signaling, which may be one potential explanation of why Tan IIA inhibits AAA development through multiple effects.

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