Active TrPs Research Articles

Myofascial Trigger Points, Neck Mobility, and Forward Head Posture in Episodic Tension‐Type Headache

To assess the differences in the presence of trigger points (TrPs) in head and neck muscles, forward head posture (FHP) and neck mobility between episodic tension-type headache (ETTH) subjects and healthy controls. In addition, we assess the relationship between these muscle TrPs, FHP, neck mobility, and several clinical variables concerning the intensity and the temporal profile of headache. TTH is a headache in which musculoskeletal disorders of the craniocervical region might play an important role in its pathogenesis. Design.-A blinded, controlled pilot study. Fifteen ETTH subjects and 15 matched controls without headache were studied. TrPs in both upper trapezius, both sternocleidomastoids, and both temporalis muscles were identified according to Simons and Gerwin diagnostic criteria (tenderness in a hypersensible spot within a palpable taut band, local twitch response elicited by snapping palpation, and elicited referred pain with palpation). Side-view pictures of each subject were taken in both sitting and standing positions, in order to assess FHP by measuring the craniovertebral angle. A cervical goniometer was employed to measure neck mobility. All measures were taken by a blinded assessor. A headache diary was kept for 4 weeks in order to assess headache intensity, frequency, and duration. The mean number of TrPs for each ETTH subject was 3.7 (SD: 1.3), of which 1.9 (SD: 0.9) were active, and 1.8 (SD: 0.9) were latent. Control subjects only had latent TrPs (mean: 1.5; SD: 1). TrP occurrence between the 2 groups was significantly different for active TrPs (P < .001), but not for latent TrPs (P > .05). Differences in the distribution of TrPs were significant for the right upper trapezius muscles (P= .04), the left sternocleidomastoid (P= .03), and both temporalis muscles (P < .001). Within the ETTH group, headache intensity, frequency, and duration outcomes did not differ depending on TrP activity, whether the TrP was active or latent. The craniovertebral angle was smaller, ie, there was a greater FHP, in ETTH patients than in healthy controls for both sitting and standing positions (P < .05). ETTH subjects with active TrPs in the analyzed muscles had a greater FHP than those with latent TrPs in both sitting and standing positions, though differences were only significant for certain muscles. Finally, ETTH patients also showed lesser neck mobility than healthy controls in the total range of motion as well as in half-cycles (except for cervical extension), although neck mobility did not seem to influence headache parameters. Active TrPs in the upper trapezius, sternocleidomastoid, and temporalis muscles were more common in ETTH subjects than in healthy controls, although TrP activity was not related to any clinical variable concerning the intensity and the temporal profile of headache. ETTH patients showed greater FHP and lesser neck mobility than healthy controls, although both disorders were not correlated with headache parameters.

Contributions of Myofascial Trigger Points to Chronic Tension Type Headache

Tension-type headache (TTH) is characterized by bilateral, pressing or tightening pain; pressure or band-like tightness; and/or increased tenderness on palpation of neck and shoulder muscles. These features resemble the descriptions of referred pain originating in myofascial trigger points (TrPs). The present paper deals with the scientific evidence supporting the hypothesis that referred pain elicited by TrPs contributes to pain perception in TTH. Animal and human studies clearly show the convergence of cervical and trigeminal afferents in the trigeminal nerve nucleus caudalis, constituting the anatomical basis for the referred head pain from neck and shoulder muscle TrPs. Referred pain patterns have been described from different TrPs in several head and neck muscles that have the potential to refer to the head. Several human pain models have confirmed some of these clinical pain patterns by injecting algogenic substances into the muscles. Recent studies have demonstrated that chronic TTH was associated with active TrPs in the suboccipital, upper trapezius, sternocleidomastoid, temporalis, and superior oblique muscles. In addition, chronic TTH patients with active TrPs have greater headache intensity and frequency than those with latent TrPs. Active TrPs have also been found on the symptomatic, but not in the contra-lateral side in unilateral migraine patients. Higher levels of algogenic substances have been found in active TrPs as compared to latent TrPs and tender points, which may lead to increased afferent bombardment into the nucleus caudalis. This would result in temporal and spatial summation of neuron signals and may cause central sensitization in chronic TTH. Pain at rest falls in this category if it results from TrP activity. It seems that the pain profile of TTH can include referred pain from TrPs in the posterior cervical, head (including extra-ocular muscles), and shoulder muscles. Further research could delineate more information on the relation between TrPs on TTH.

Myofascial Trigger Points, Neck Mobility and Forward Head Posture in Unilateral Migraine

This paper describes the differences in the presence of myofascial trigger points (TrPs) in the upper trapezius, sternocleidomastoid, temporalis and suboccipital muscles between unilateral migraine subjects and healthy controls, and the differences in the presence of TrPs between the symptomatic side and the non-symptomatic side in migraine subjects. In addition, we assess the differences in the presence of both forward head posture (FHP) and active neck mobility between migraine subjects and healthy controls and the relationship between FHP and neck mobility. Twenty subjects with unilateral migraine without side-shift and 20 matched controls participated. TrPs were identified when there was a hypersensible tender spot in a palpable taut band, local twitch response elicited by the snapping palpation of the taut band and reproduction of the referred pain typical of each TrP. Side-view pictures were taken in both sitting and standing positions to measure the cranio-vertebral angle. A cervical goniometer was employed to measure neck mobility. Migraine subjects showed a significantly greater number of active TrPs (P<0.001), but not latent TrPs, than healthy controls. Active TrPs were mostly located ipsilateral to migraine headaches (P<0.01). Migraine subjects showed a smaller cranio-vertebral angle than controls (P<0.001), thus presenting a greater FHP. Neck mobility in migraine subjects was less than in controls only for extension (P=0.02) and the total range of motion in flexion/extension (P=0.01). However, there was a positive correlation between the cranio-vertebral angle and neck mobility. Nociceptive inputs from TrPs in head and neck muscles may produce continuous afferent bombardment of the trigeminal nerve nucleus caudalis and, thence, activation of the trigeminovascular system. Active TrPs located ipsilateral to migraine headaches might be a contributing factor in the initiation or perpetuation of migraine.

Referred pain from trapezius muscle trigger points shares similar characteristics with chronic tension type headache

Referred pain and pain characteristics evoked from the upper trapezius muscle was investigated in 20 patients with chronic tension-type headache (CTTH) and 20 age- and gender-matched controls. A headache diary was kept for 4 weeks in order to confirm the diagnosis and record the pain history. Both upper trapezius muscles were examined for the presence of myofascial trigger points (TrPs) in a blinded fashion. The local and referred pain intensities, referred pain pattern, and pressure pain threshold (PPT) were recorded. The results show that referred pain was evoked in 85% and 50% on the dominant and non-dominant sides in CTTH patients, much higher than 55% and 25% in controls ( P < 0.01). Referred pain spread to the posterior-lateral aspect of the neck ipsi-lateral to the stimulated muscle in both patients and controls, with additional referral to the temple in most patients, but none in controls. Nearly half of the CTTH patients (45%) recognized the referred pain as their usual headache sensation, i.e. active TrPs. CTTH patients with active TrPs in the right upper trapezius muscle showed greater headache intensity and frequency, and longer headache duration than those with latent TrPs. CTTH patients with bilateral TrPs reported significantly decreased PPT than those with unilateral TrP ( P < 0.01). Our results showed that manual exploration of TrPs in the upper trapezius muscle elicited referred pain patterns in both CTTH patients and healthy subjects. In CTTH patients, the evoked referred pain and its sensory characteristics shared similar patterns as their habitual headache pain, consistent with active TrPs. Our results suggest that spatial summation of perceived pain and mechanical pain sensitivity exists in CTTH patients.

Myofascial trigger points in the suboccipital muscles in episodic tension-type headache

Referred pain evoked by suboccipital muscle trigger points (TrPs) spreads to the side of the head over the occipital and temporal bones and is usually perceived as bilateral headache. This paper describes the presence of referred pain from suboccipital muscle TrPs in subjects with episodic tension-type headache (ETTH) and in healthy controls. Ten patients presenting with ETTH and 10 matched controls without headache were examined by a blinded assessor for the presence of suboccipital muscle TrPs. Diagnostic criteria described by Simons and Gerwin were adapted to diagnose TrPs, i.e. presence of tenderness in the suboccipital region, referred pain evoked by maintained pressure for 10 s, and increased referred pain on muscle contraction. Six ETTH patients (60%) had active TrPs and 4 had latent TrPs (40%). On the other hand, 2 control subjects also had latent TrPs. Differences in the presence of suboccipital muscle TrPs between both groups were significant for active TrPs ( P < 0.001 ), but not for latent TrPs. Active TrPs were only present in ETTH patients, although TrP activity was not related to any clinical variable concerning the intensity and the temporal profile of headache. Myofascial TrPs in the suboccipital muscles might contribute to the origin and/or maintenance of headache, but a comprehensive knowledge of the role of these muscles in tension-type headache awaits further research.

Myofascial trigger points in subjects presenting with mechanical neck pain: A blinded, controlled study

The aim of this study was to describe the differences in the presence of myofascial trigger points (TrPs) in the upper trapezius, sternocleidomastoid, levator scapulae and suboccipital muscles between patients presenting with mechanical neck pain and control healthy subjects. Twenty subjects with mechanical neck pain and 20 matched healthy controls participated in this study. TrPs were identified, by an assessor blinded to the subjects’ condition, when there was a hypersensible tender spot in a palpable taut band, local twitch response elicited by the snapping palpation of the taut band, and reproduction of the referred pain typical of each TrP. The mean number of TrPs present on each neck pain patient was 4.3 (SD: 0.9), of which 2.5 (SD: 1.3) were latent and 1.8 (SD: 0.8) were active TrPs. Control subjects also exhibited TrPs (mean: 2; SD: 0.8). All were latent TrPs. Differences in the number of TrPs between both study groups were significant for active TrPs ( P<0.001), but not for latent TrPs ( P>0.5). Moreover, differences in the distribution of TrPs within the analysed cervical muscles were also significant ( P<0.01) for all muscles except for both levator scapulae. All the examined muscles evoked referred pain patterns contributing to patients’ symptoms. Active TrPs were more frequent in patients presenting with mechanical neck pain than in healthy subjects.

Myofascial Trigger Points and Their Relationship to Headache Clinical Parameters in Chronic Tension‐Type Headache

To assess the presence of trigger points (TrPs) in several head and neck muscles in subjects with chronic tension-type headache (CTTH) and in healthy subjects; and to evaluate the relationship of these TrPs with forward head posture (FHP), headache intensity, duration, and frequency. Tension-type headache (TTH) is a headache in which myofascial TrPs in head and neck muscles might play an important etiologic role. A blinded, controlled, pilot study. Twenty-five CTTH subjects and 25 matched controls without headache were studied. TrPs in bilateral upper trapezius, sternocleidomastoids, and temporalis muscles were identified according to Simons et al's diagnostic criteria: tenderness in a hyperirritable spot within a palpable taut band, local twitch response elicited by snapping palpation, and elicited referred pain with palpation. A TrP was considered active if the subject recognized the evoked referred pain as familiar headache. If the evoked referred pain was not recognized as familiar headache, the TrP was considered as latent. Side-view pictures of each subject were taken in both sitting and standing positions in order to assess FHP by measuring the cranio-vertebral angle. Both measurements were made by a blinded assessor. A headache diary was kept for 4 weeks in order to assess headache intensity, frequency, and duration. The mean number of TrPs on each CTTH subject was 3.9 (SD: 1.2), of which 1.9 (SD: 1.2) were active TrPs and 1.9 (SD: 0.8) were latent TrPs. Control subjects only exhibited latent TrPs (mean: 1.4; SD: 0.8). There was a significant difference between the CTTH group and the controls for active TrPs (P < .001), but not for latent TrPs (P > .05). Differences in the distribution of active and latent TrPs within each muscle were also significant for all the analyzed muscles (P < .01). CTTH subjects with active TrPs in the right upper trapezius muscle or left sternocleidomastoid muscle showed a greater headache intensity and duration, but not headache frequency, compared to those with latent TrPs (P < .05). Active TrPs in the right temporalis muscle were associated with longer headache duration (P < .01), whereas active TrPs in the left temporalis muscle were associated with greater headache intensity (P < .05). CTTH subjects with active TrPs in the analyzed muscles had a greater FHP than those with latent TrPs in both sitting and standing positions. Differences were only significant for TrPs in the left sternocleidomastoid and FHP in the sitting position (P < .01). Active TrPs in upper trapezius, sternocleidomastoid, and temporalis muscles were associated with CTTH. CTTH subjects with active TrPs usually reported a greater headache intensity and longer headache duration than those with latent TrPs. CTTH subjects with active TrPs tended to have a greater FHP than CTTH subjects with latent TrPs.

Trigger Points in the Suboccipital Muscles and Forward Head Posture in Tension‐Type Headache

To assess the presence of trigger points (TrPs) in the suboccipital muscles and forward head posture (FHP) in subjects with chronic tension-type headache (CTTH) and in healthy subjects, and to evaluate the relationship of TrPs and FHP with headache intensity, duration, and frequency. Tension-type headache (TTH) is a prototypical headache in which myofascial TrPs in the cervical and pericranial musculature can play an important role. A blinded, controlled pilot study. Twenty CTTH subjects and 20 matched controls without headache participated. TrPs were identified by eliciting referred pain with palpation, and increased referred pain with muscle contraction. Side-view pictures of each subject were taken in sitting and standing positions, in order to assess FHP by measuring the craniovertebral angle. Both measures were taken by a blinded assessor. A headache diary was kept for 4 weeks in order to assess headache intensity, frequency, and duration. Sixty-five percent (13/20) CTTH subjects showed active TrPs and 35% (7/20) had latent TrPs in the suboccipital muscles. Six (30%) controls also had latent TrPs. Differences in the presence of suboccipital muscle TrPs between both the groups were significant for active TrPs (P < .001) but not for latent TrPs (P > .5). CTTH subjects with active TrPs reported a greater headache intensity and frequency than those with latent TrPs (P < .05). The degree of FHP was greater in CTTH subjects than in controls in both sitting and standing positions (P < .01). Within the CTTH group, there was a negative correlation between the craniovertebral angle and the frequency of headache (r(s) = -0.6, P < .01, in sitting position; r(s) = -0.5, P < .05, in standing position). CTTH subjects with active TrPs had a greater FHP than those with latent TrPs, though this difference was not significant. Suboccipital active TrPs and FHP were associated with CTTH. CCTH subjects with active TrPs reported a greater headache intensity and frequency than those with latent TrPs. The degree of FHP correlated positively with headache duration, headache frequency, and the presence of suboccipital active TrPs.

Musculoskeletal Disorders in Mechanical Neck Pain: Myofascial Trigger Points versus Cervical Joint Dysfunction–A Clinical Study

Objective: Some authors have hypothesized that the pathogenesis of mechanical neck pain is mainly produced by musculoskeletal disorders, i.e., myofascial pain syndrome trigger points [TrPs] and cervical joint dysfunctions. The relationship between muscles and joint dysfunctions is well recognized by clinicians, but there are not many published papers analyzing this clinical situation. The aim of the present trial was to analyze the relationship between the presence of TrPs in the upper trapezius muscle and the presence of cervical dysfunctions at C3 and/or C4 vertebrae in patients suffering from mechanical neck pain.Methods: One hundred and fifty patients suffering from mechanical neck pain participated in this clinical trial. Patients were examined for TrPs by Therapist 1 and for cervical dysfunctions by Therapist 2. Both therapists were blinded to the other physical exploration. The diagnosis of the TrPs was based upon the diagnostic criteria of Travell and Simons. Pressure on the TrPs was applied with a Pressure Threshold Meter and was increased continuously approximately at a rate of 1 kg/cm2/seg to a maximum of 2.5 kg/cm2 of pressure. Physical examination of cervical dysfunction was based upon the “lateral gliding test for the cervical spine” following the guideline described by Greenman.Results: Latent TrPs in the upper trapezius muscle were shown in 56 percent of patients, whereas 28 percent subjects showed active TrPs. The remaining patients did not show TrPs, but rather tender points [TePs] were found. Ninety-seven percent of subjects showed a cervical dysfunction ipsilateral to the TrP or TeP. Further analysis showed a significant relationship between the presence of TrPs in the upper trapezius muscle and the isolate presence of a dysfunction at C3 vertebra [P = 0.03], and the presence of dual dysfunctions at C3 and C4 vertebrae [P = 0.03].Conclusion: There is a possible relationship between the presence of TrPs in the upper trapezius muscle and the presence of cervical dysfunctions at C3 and C4 vertebrae in patients suffering from mechanical neck pain. However, it can not be established as a cause-effect relationship. Moreover, there is clinical evidence showing that joint dysfunctions can induce TrP activity, and that TrP activity can aggravate corresponding joint dysfunction.

Myofascial Pain Therapy

SUMMARYBackground: The most important strategy in myofascial pain syndrome therapy is to identify the etiological lesion that causes the activation of myofascial trigger points [s] and to treat the underlying pathology. If the underlying etiological lesion is not appropriately treated, the TrP can only be inactivated temporarily, and never completely.Findings: Generally, active TrPs should be treated conservatively with non-invasive techniques such as physical therapy prior to the consideration of aggressive therapy with invasive techniques such as needling and injection. This principle should also be observed when treating the underlying etiological lesions. Conservative therapy, such as manual therapy combined with thermotherapy and electrotherapy, can usually inactivate painful TrPs. Other situations, however, might necessitate dry needling or TrP injection: 1. persistent pain or discomfort after complete elimination of the underlying pathological lesion responsible for TrP activation, 2. poor response...

New Aspects of Myofascial Trigger Points: Etiological and Clinical

SUMMARYObjectives: To identify important new developments in our understanding of the nature and clinical characteristics of myofascial trigger points [TrPs].Findings: Recent research studies reinforce the credibility of three key features of an integrated hypothesis that is designed to explain the pathophysiology of TrPs: increased acetylcholine effect, increased muscle-fiber tension, and local release of sensitizing substances. Electromyographic studies of TrPs support an increased acetylcholine effect that produces endplate noise. Nine histological studies of animal and human subjects identify features that indicate abnormally increased muscle-fiber tension and help to account for the taut bands observed clinically. Microdialysis studies by Jay Shah, MD and colleagues at the National Institutes of Health compared, in nine subjects, the findings in active TrPs to findings in latent TrPs and in normal muscles [nine examinations]. They found a significantly reduced pressure pain threshold and pH at the th...

Difference in pain relief after trigger point injections in myofascial pain patients with and without fibromyalgia

Objective: To compare responses to trigger point (TrP) injection between patients having both myofascial pain syndrome (MPS) caused by active TrPs and fibromyalgia syndrome (FMS) and patients with MPS due to TrPs but without FMS. Design: Prospective design blinded measurement, before-after trial. Setting: A pain control medical clinic. Patients: Group 1: MPS + FMS; Group 2: MPS only. All patients (9 in each group) had active TrPs in the upper trapezius muscle. Intervention: Myofascial TrP injection with 0.5% xylocaine. Main Outcome Measures: Subjective pain intensity (PI), pain threshold (PT), and range of motion (ROM) were assessed before, immediately after, and 2 weeks after TrP injection. Results: In a comparison of preinjection measures to immediate postinjection measures, only ROM was significantly improved ( p < .05) in Group 1 patients; all three parameters were significantly improved ( p < .05) in the Group 2 patients who had only MPS. Two weeks after injection, both groups showed significant improvement ( p < .05) in all three measured parameters as compared to preinjection measurements. In a comparison of the two groups, the immediate effectiveness of TrP injection was significantly iless ( p < .05) in Group 1 than in Group 2 for all three parameters. Two weeks after injection, the degree of improvement in PT or ROM (but not PI) was not significantly different between two groups. Postinjection soreness (different from myofascial pain) was more severe, developed sooner, and lasted longer in Group 1 than in Group 2. Conclusions: Trigger point injection is a valuable procedure for pain relief for patients in both group. Patients with FMS are likely to experience significant but delayed and attenuated pain relief following injection of their active TrPs compared to myofascial pain patients with similar TrPs but without FMS. Also, FMS patients are likely to experience significantly more postinjection soreness for a longer period of time.

Pressure Threshold for Referred Pain by Compression on the Trigger Point and Adjacent Areas

Objective: This study is designed to investigate the amount of pressure on a myofascial pain trigger point [TrP] sufficient to initiate referred pain. Methods: Sensitive spots in palpable taut bands of extensor digitorum communis muscles in Group 1 subjects with latent TrPs [no spontaneous pain but tender] and in Group 2 patients with active TrPs [with spontaneous pain] were studied. A pressure algometer was used to measure the threshold of the pressure sufficient to induce local pain, referred pain and intolerable pain for each subject. The TrP [site A], a non-TrP location [site B] in the same taut band, and a control site in normal muscle tissue free of taut bands [site C] were measured. Results: It was found that the referred pain could be elicited with a higher incidence at site A [46.8% for a latent TrP; 100% for an active TrP] than at site B [36.2% for a latent TrP; 100% for an active TrP] than at site C [23.4% for a latent TrP; 68.0% for an active TrP]. For either a latent TrP or an active TrP, t...

Myofascial Pain Syndromes

The criteria for performing a diagnosis of myofascial pain syndromes caused by trigger points (TrPs) are defined and the clinical features of pain and related phenomena due to these syndromes are examined together with the sensory modifications of the parietal tissues at TrPs and target level in the case of both active and latent TrPs. The factors presumably responsible for the occurrence of TrPs in myofascial structures are then considered, with particular emphasis on the microtraumatic event caused by biomechanical alterations during movement, evaluated by the analysis of the ground-foot reaction. With this respect, some examples of myofascial pain syndromes of the lower limbs are reported in which the correction of these alterations, performed via dynamic orthosis, produces a long-lasting remission of the subjective and objective symptomatology.

Myofascial Pain Syndromes

The criteria for performing a diagnosis of myofascial pain syndromes caused by trigger points (TrPs) are defined and the clinical features of pain and related phenomena due to these syndromes are examined together with the sensory modifications of the parietal tissues at TrPs and target level in the case of both active and latent TrPs. The factors presumably responsible for the occurrence of TrPs in myofascial structures are then considered, with particular emphasis on the microtraumatic event caused by biomechanical alterations during movement, evaluated by the analysis of the ground-foot reaction. With this respect, some examples of myofascial pain syndromes of the lower limbs are reported in which the correction of these alterations, performed via dynamic orthosis, produces a long-lasting remission of the subjective and objective symptomatology.