Myofascial Trigger Points: Pathophysiology and Correlation with Acupuncture Points

2000 ◽  
Vol 18 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Chang-Zern Hong
Keyword(s):  
Spinal Cord ◽  
Electrical Activity ◽  
Science Studies ◽  
Trigger Points ◽  
Referred Pain ◽  
Acupuncture Points ◽  
Myofascial Trigger Points ◽  
Spontaneous Electrical Activity ◽  
Twitch Response ◽  
Active Locus

A review is made of recent studies on myofascial trigger points (MTrP) and their mechanism is discussed. Clinical and basic science studies have shown that there are multiple MTrP loci in a MTrP region. A MTrP locus contains a sensory component (sensitive locus) and a motor component (active locus). A sensitive locus is a point from which tenderness or pain, referred pain, and local twitch response can be elicited by mechanical stimulation. Sensitive loci (probably sensitised nociceptors) are widely distributed in the whole muscle, but are concentrated in the endplate zone. An active locus is a site from which spontaneous electrical activity can be recorded. Active loci appear to be dysfunctional endplates since spontaneous electrical activity is essentially the same as the electrical activity reported by neurophysiologists as that recorded from an abnormal endplate. A MTrP is always found in a taut band which is histologically related to contraction knots caused by excessive release of acetylcholine in abnormal endplates. Both referred pain and local twitch response are mediated through spinal cord mechanisms, as demonstrated in both human and animal studies. The pathogenesis of MTrPs appears to be related to integration in the spinal cord of response to the disturbance of nerve endings and abnormal contractile mechanism at multiple dysfunctional endplates. There are many similarities between MTrPs and acupuncture points including their location and distribution, pain and referred pain patterns, local twitch responses (de qi), and possible spinal cord mechanism.

scholarly journals Myelinated Afferents Are Involved in Pathology of the Spontaneous Electrical Activity and Mechanical Hyperalgesia of Myofascial Trigger Spots in Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Fei Meng ◽  
Hong-You Ge ◽  
Yong-Hui Wang ◽  
Shou-Wei Yue
Keyword(s):  
Electrical Activity ◽  
Behavioral Assessment ◽  
Trigger Points ◽  
Mechanical Hyperalgesia ◽  
Myofascial Trigger Points ◽  
Spontaneous Electrical Activity ◽  
Muscular Pain ◽  
Common Causes ◽  
Neurofilament 200 ◽  
Mechanical Pain Thresholds

Myofascial trigger points (MTrPs) are common causes for chronic pain. Myelinated afferents were considered to be related with muscular pain, and our clinical researches indicated they might participate in the pathology of MTrPs. Here, we applied myofascial trigger spots (MTrSs, equal to MTrPs in human) of rats to further investigate role of myelinated afferents. Modified pyridine-silver staining revealed more nerve endings at MTrSs than non-MTrSs (P<0.01), and immunohistochemistry with Neurofilament 200 indicated more myelinated afferents existed in MTrSs (P<0.01). Spontaneous electrical activity (SEA) recordings at MTrSs showed that specific block of myelinated afferents in sciatic nerve with tetrodotoxin (TTX) led to significantly decreased SEA (P<0.05). Behavioral assessment showed that mechanical pain thresholds (MPTs) of MTrSs were lower than those of non-MTrSs (P<0.01). Block of myelinated afferents by intramuscular TTX injection increased MPTs of MTrSs significantly (P<0.01), while MPTs of non-MTrSs first decreased (P<0.05) and then increased (P>0.05). 30 min after the injection, MPTs at MTrSs were significantly lower than those of non-MTrSs (P<0.01). Therefore, we concluded that proliferated myelinated afferents existed at MTrSs, which were closely related to pathology of SEA and mechanical hyperalgesia of MTrSs.

Needle Electromyographic Activity of Myofascial Trigger Points and Control Sites in Equine Cleido-Brachialis Muscle – An Observational Study

2006 ◽  
Vol 24 (2) ◽  
pp. 61-70 ◽  
Author(s):  
Joanne Macgregor ◽  
Dietrich Graf von Schweinitz
Keyword(s):  
Skeletal Muscle ◽  
Electrical Activity ◽  
Muscle Tissue ◽  
Spike Activity ◽  
Trigger Point ◽  
Trigger Points ◽  
Emg Activity ◽  
Electromyographic Activity ◽  
Myofascial Trigger Points ◽  
Spontaneous Electrical Activity

Background Myofascial trigger points are commonly described in humans, and many studies have shown abnormal spontaneous electrical activity, spike activity and local twitch responses at these sites. Myofascial trigger points have only rarely been described in horses, and studies of their electrophysiological characteristics have not previously been published. The objective of this study was to explore the electromyographic (EMG) and other characteristics of myofascial trigger points in equine muscle, and to compare them with normal muscle tissue. Methods Four horses with chronic pain signs and impaired performance were examined. They had previously been examined at the second author's practice, and showed signs compatible with the diagnosis of myofascial trigger points in their cleidobrachialis (brachiocephalic) muscle, ie localised tender spots in a taut band of skeletal muscle which produced a local twitch response on snapping palpation. They had therefore been selected for treatment with acupuncture. Needle EMG activity and twitch responses were recorded at 25 positions at the trigger point and at a nearby control point during the course of each horse's acupuncture treatment. Results All subjects demonstrated objective signs of spontaneous electrical activity, spike activity and local twitch responses at the myofascial trigger point sites within taut bands. The frequency of these signs was significantly greater at myofascial trigger points than at control sites (P<0.05). Conclusion Equine myofascial trigger points can be identified, and have similar objective signs and electrophysiological properties to those documented in human and rabbit skeletal muscle tissue. The important differences from findings in human studies are that referred pain patterns and the reproduction of pain profile cannot be determined in animals.

The Local and Referred Pain From Myofascial Trigger Points in the Temporalis Muscle Contributes to Pain Profile in Chronic Tension-type Headache

2007 ◽  
Vol 23 (9) ◽  
pp. 786-792 ◽  
Author(s):  
César Fernández-de-las-Peñas ◽  
Hong-You Ge ◽  
Lars Arendt-Nielsen ◽  
Maria Luz Cuadrado ◽  
Juan A. Pareja
Keyword(s):  
Trigger Points ◽  
Tension Type Headache ◽  
Referred Pain ◽  
Temporalis Muscle ◽  
Myofascial Trigger Points ◽  
Chronic Tension Type Headache ◽  
Type Headache

Myofascial Trigger Points and Sensitization: An Updated Pain Model for Tension-Type Headache

Cephalalgia ◽  
2007 ◽  
Vol 27 (5) ◽  
pp. 383-393 ◽  
Author(s):  
C Fernández-de-las-Peñas ◽  
ML Cuadrado ◽  
L Arendt-Nielsen ◽  
DG Simons ◽  
JA Pareja
Keyword(s):  
Central Sensitization ◽  
Trigger Point ◽  
Trigger Points ◽  
Tension Type Headache ◽  
Referred Pain ◽  
Tender Points ◽  
Myofascial Trigger Points ◽  
Pain Model ◽  
Type Headache ◽  
Chemical Mediators

Present pain models for tension-type headache suggest that nociceptive inputs from peripheral tender muscles can lead to central sensitization and chronic tension-type headache (CTTH) conditions. Such models support that possible peripheral mechanisms leading to pericranial tenderness include activation or sensitization of nociceptive nerve endings by liberation of chemical mediators (bradikinin, serotonin, substance P). However, a study has found that nonspecific tender points in CTTH subjects were not responsible for liberation of algogenic substances in the periphery. Assuming that liberation of algogenic substances is important, the question arising is: if tender muscle points are not the primary sites of on-going neurogenic inflammation, which structure can be responsible for liberation of chemical mediators in the periphery? A recent study has found higher levels of algogenic substances, and lower pH levels, in active myofascial trigger point (TrPs) compared with control tender points. Clinical studies have demonstrated that referred pain elicited by head and neck muscles contribute to head pain patterns in CTTH. Based on available data, an updated pain model for CTTH is proposed in which headache can at least partly be explained by referred pain from TrPs in the posterior cervical, head and shoulder muscles. In this updated pain model, TrPs would be the primary hyperalgesic zones responsible for the development of central sensitization in CTTH.

Referred pain areas of active myofascial trigger points in head, neck, and shoulder muscles, in chronic tension type headache

2010 ◽  
Vol 14 (4) ◽  
pp. 391-396 ◽  
Author(s):  
César Fernández-de-las-Peñas ◽  
Hong-You Ge ◽  
Cristina Alonso-Blanco ◽  
Javier González-Iglesias ◽  
Lars Arendt-Nielsen
Keyword(s):  
Trigger Points ◽  
Tension Type Headache ◽  
Referred Pain ◽  
Myofascial Trigger Points ◽  
Chronic Tension Type Headache ◽  
Shoulder Muscles ◽  
Type Headache ◽  
Head Neck
Sign in / Sign up

Export Citation Format

Share Document