Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Trigger Points”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2Linked to original sources

Trigger points and tender points: one and the same? Does injection treatment help?

Trigger points are defined as areas of muscle that are painful to palpation and are characterized by the presence of taut bands and the generation of a referral pattern of pain. Tender points are areas of tenderness occurring in muscle, muscle-tendon junction, bursa, or fat pad. When tender points occur in a widespread manner, they are usually considered characteristic of fibromyalgia. Trigger points, which typically occur in a more restricted regional pattern, are indicative of myofascial pain syndrome. In some patients the two phenomena may coexists, and overlap syndromes can occur. Although experienced examiners can generally identify the same tender points, interrater reliability of trigger points has been low in most studies. There is continued controversy regarding the defining characteristics and homogeneity of myofascial pain because of the variability of the examination findings. In appropriately selected patients, it appears that myofascial trigger point injections can be helpful in decreasing pain and improving range of motion in conjunction with a comprehensive exercise and rehabilitation program.

Fibromyalgia↗

Needle electromyographic activity of myofascial trigger points and control sites in equine cleidobrachialis muscle--an observational study.

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.

Acupuncture Therapy↗

Differentiation of active and latent trigger points by thermography.

OBJECTIVE: This study tested whether two distinct thermographic patterns attributed to myofascial trigger points could distinguish between active and latent trigger points. DESIGN: A retrospective chart survey was undertaken with thermographic data divided into two groups: a) increased thermal emission only over the trigger point and b) over the area of pain referral. The criterion standard used in a blinded comparison was physical examination findings separating active from latent trigger points. SETTING: All cases were drawn from a private practice referral center for thermographic evaluation of neck and low back injuries. PATIENTS: A sample of 65 cases showing physical examination findings of trigger points was chosen from 229 consecutive motor vehicle accident case files. RESULTS: There was moderate agreement between the two methods of differentiating active from latent latent trigger points (Kappa = 0.44) with a specificity of 0.70 and a sensitivity of 0.74. When cases in which spinal segmental dysfunction were eliminated, the agreement increased (Kappa = 0.54) with specificity of 0.82 and sensitivity of 0.74. CONCLUSIONS: Thermography may be a useful tool in distinguishing active from latent trigger points, but the thermal imaging of spinal joint dysfunction may be a compounding factor.

Cervical Vertebrae↗

Endplate potentials are common to midfiber myofacial trigger points.

OBJECTIVES: To compare the prevalence of motor endplate potentials (noise and spikes) in active central myofascial trigger points, endplate zones, and taut bands of skeletal muscle to assess the specificity of endplate potentials to myofascial trigger points. DESIGN: This nonrandomized, unblinded needle examination of myofascial trigger points compares the prevalence of three forms of endplate potentials at one test site and two control sites in 11 muscles of 10 subjects. The endplate zone was independently determined electrically. Active central myofascial trigger points were identified by spot tenderness in a palpable taut band of muscle, a local twitch response to snapping palpation, and the subject's recognition of pain elicited by pressure on the tender spot. RESULTS: Endplate noise without spikes occurred in all 11 muscles at trigger-point sites, in four muscles at endplate zone sites outside of trigger points (P = 0.024), and did not occur in taut band sites outside of an endplate zone (P = 0.000034). CONCLUSIONS: Endplate noise was significantly more prevalent in myofascial trigger points than in sites that were outside of a trigger point but still within the endplate zone. Endplate noise seems to be characteristic of, but is not restricted to, the region of a myofascial trigger point.

Adult↗

Lateralization of headache: possible role of an upper cervical trigger point.

An ipsilateral upper neck trigger point was found in 21 of 24 patients with unilateral headache. During the prodromic period this trigger point was detected as a tender protrusion on neck palpation. In 18 out of 24 patients it was also found during the headache-free period. On standard roentgenogram, this protrusion seemed to be a laterally developed C2 spinous process. The EMG study showed latent trapezius hypertonicity on the side of the headache, even during the headache-free period. The association of the painful protrusion and trapezius hypertonicity could create an autoreinforcing nociceptive loop, which in turn could be the cause of lateralization of the pain.

Adult↗

Levator ani trigger point injections: An underutilized treatment for chronic pelvic pain.

AIMS: We conducted this study to examine the role of trigger point injections in females with chronic pelvic pain (CPP) of at least 6 months duration and specific levator ani trigger points. METHODS: This prospective study included 18 consecutive female patients with CPP and specific palpable levator ani trigger points. Pain was evaluated before and after trigger point injection on a Visual Analog Scale (VAS). Patient global satisfaction (PGS) and cure rates (PGC) were also measured by a VAS on a scale of 0-100%. The trigger points were identified manually by intravaginal palpation of the levator ani bilaterally. A mixture of 10 cc of 0.25% bupivacaine, 10 cc of 2% lidocaine and 1 cc (40 mg) of triamcinolone was used for injection of 5 cc per trigger point. A 5.5'' Iowa trumpet pudendal needle guide was used for injection. All but one injection were performed in the office setting without sedation. Pelvic floor muscle exercises were taught for use after injection. Success was defined as a decrease in pain as measured by a VAS of 50% or more, as well as PGS and PGC scores of 60% or greater. There was a mean follow up of 3 months after trigger point injection. RESULTS: Thirteen of 18 women improved with the first trigger point injection resulting in a comprehensive success rate of 72%. Six (33%) of 18 women were completely pain free. CONCLUSION: In the management of CPP, a non-surgical office-based therapy such as trigger point injections can be effective in selected patients.

Adult↗

Fibrositic myofascial pain in intermittent claudication. Effect of anesthetic block of trigger points on exercise tolerance.

The blocking of trigger points in the calf by the local injection of an anesthetic agent was performed in 15 patients with intermittent claudication. Reactive and exercise hyperemia, work load and duration of exercise were recorded before and after infiltration of the trigger points. Reactive hyperemia does not change, but the exercise tolerance of the leg significantly improves after local blocking of the trigger areas and the exercise hyperemia increases because of the higher work load. The pain pattern of intermittent claudication can be activated by the summation of abnormal input from muscles, due to contraction in the presence of anoxia, with activity from trigger points. Local infiltration of trigger areas blocks theirir activity. The vicious cycle of pain is interrupted and the exercise tolerance of the leg is increased, without improving blood circulation.

Adult↗

Effectiveness of a home program of ischemic pressure followed by sustained stretch for treatment of myofascial trigger points.

BACKGROUND AND PURPOSE: Myofascial trigger points (TPs) are found among patients who have neck and upper back pain. The purpose of this study was to determine the effectiveness of a home program of ischemic pressure followed by sustained stretching for the treatment of myofascial TPs. SUBJECTS: Forty adults (17 male, 23 female), aged 23 to 58 years (mean=30.6, SD=9.3), with one or more TPs in the neck or upper back participated in this study. METHODS: Subjects were randomly divided into 2 groups receiving a 5-day home program of either ischemic pressure followed by general sustained stretching of the neck and upper back musculature or a control treatment of active range of motion. Measurements were obtained before the subjects received the home program instruction and on the third day after they discontinued treatment. Trigger point sensitivity was measured with a pressure algometer as pressure pain threshold (PPT). Average pain intensity for a 24-hour period was scored on a visual analog scale (VAS). Subjects also reported the percentage of time in pain over a 24-hour period. A multivariate analysis of covariance, with the pretests as the covariates, was performed and followed by 3 analyses of covariance, 1 for each variable. RESULTS Differences were found between the treatment and control groups for VAS scores and PPT. No difference was found between the groups for percentage of time in pain. CONCLUSION AND DISCUSSION: A home program, consisting of ischemic pressure and sustained stretching, was shown to be effective in reducing TP sensitivity and pain intensity in individuals with neck and upper back pain. The results of this study indicate that clinicians can treat myofascial TPs through monitoring of a home program of ischemic pressure and stretching.

Adult↗

The effects of myofascial trigger point injections are naloxone reversible.

Ten patients with myofascial trigger point pain were entered into a double-blind cross-over study of the reversibility of myofascial trigger point injection (TPI) effects with naloxone versus placebo in order to test the hypothesis that the benefits of TPI are mediated, at least in part, through activation of an endogenous opioid system. Injection of trigger points with 0.25% bupivacaine decreased pain in all subjects and increased range of motion in subjects who, on initial assessment, demonstrated limitations of movement of the affected part(s). Allodynia and palpable bands preceding TPI when present also showed reduction after TPI. All improvements afforded by TPI were significantly reversed with intravenous naloxone (10 mg) compared to intravenous placebo. These results demonstrate a naloxone-reversible mechanism in TPI therapy. This suggests an endogenous opioid system as a mediator for the decreased pain and improved physical findings following injection of myofascial trigger points with local anesthetic.

Adult↗

Myofascial trigger points in persistent posttraumatic shoulder pain.

Persistent pain and disability after injuries to the shoulder sometimes create a difficult diagnostic and therapeutic problem. In many such cases, myofascial trigger points seem to cause symptoms. Three cases in which pain had persisted for eight to 33 months after injury illustrate the manifestations of posttraumatic myofascial trigger point disorders. Trigger points are located by finding discrete foci of tenderness in muscles. Trigger points may be palpably firmer than surrounding muscle, forming nodules; they may twitch in response to palpation and may refer pain to a specific area when stimulated. Failure to recognize the myofascial source of pain can lead to erroneous diagnoses of articular, neurologic, or emotional disorder. Current pathophysiologic theories about trigger points may explain the persistence and topographic spreading of pain after muscular injuries. Appropriate treatment of myofascial trigger points can relieve chronic pain and disability.

Accidents, Occupational↗

Trigger point evaluation in migraine patients: an indication of peripheral sensitization linked to migraine predisposition?

Although migraine is a neurovascular disorder, both scalp tenderness and referred pain have been observed in migraine patients. The present study was carried out to investigate the presence of trigger points eliciting referred pain in 98 migraine patients and in 32 healthy subjects. Trigger points were found in 92 (93.9%) migraineurs and in nine (29%) controls (P < 0.0001). The number of individual migraine trigger points varied from zero to 14 (modal number: 4), and was found to be related to both the frequency of migraine attacks (P < 0.0001), and the duration of the disease (P = 0.017). About 74% of the total detected trigger points were found in temporal and/or suboccipital areas; other locations were mainly found in patients showing more than four trigger points. Trigger point palpation provoked a migraine attack in 30 (30.6%) patients. Pericraneal allodynia was found in 15 (15.3%) patients. These data indicate that nociceptive peripheral sensitization is a usual finding in migraine, and that central sensitization can develop in patients with frequent attacks and long-lasting disease. Trigger points' detection in migraine patients could be useful when applying therapies like acupuncture, needling or botulinum toxin injections directed to reduce peripheral sensitization.

Adolescent↗

Trigger point injections vs. jet injection in the treatment of myofascial pain.

Trigger point injections using dilute solutions of local anesthetic agents have proved effective for many patients with myofascial pain. The treatment itself, however, can produce severe pain and may occasionally be associated with complications. It was determined in this study that a local anesthetic solution administered by jet injection in the area of myofascial trigger points was capable of providing short-term pain relief equal to conventional trigger point injections using a hypodermic needle and syringe. The jet injector system produced significantly less pain during treatment than conventional trigger point injections and therefore was preferred by most subjects having the opportunity to compare both forms of treatment.

Adult↗

Thermographic imaging of myofascial trigger points: a follow-up study.

Thermographic evaluation was performed on 11 adult volunteers with myofascial trigger points and on 11 asymptomatic controls. Infrared thermography was used to obtain a series of images to compare the sensory referral areas of myofascial trigger points with their thermal referral patterns. A series of images was then taken at, and distal to, the sensory referral area of each trigger point during quantitative compression of the trigger point, and dynamic temperature changes were monitored. Asymmetric thermal patterns were observed at all trigger points in the sensory referral area and distal to the referred area before compression. The thermal referral areas showed a reduction in temperature from precompression levels during compression. When similar but asymptomatic areas were compressed, no significant changes in temperature were noted at distal sites.

Adult↗

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.

Chronic Disease↗

Botulinum toxin A versus bupivacaine trigger point injections for the treatment of myofascial pain syndrome: a randomised double blind crossover study.

The treatment of myofascial pain syndrome (MPS) is diverse and includes trigger point injections of various substances including local anesthetics, steroids and Botulinum toxin A (BTX A). The purpose of this study was to compare the effectiveness of trigger point injections using BTX A versus bupivacaine, both in combination with a home-based rehabilitation program. To be enrolled, subjects first had to demonstrate responsiveness to bupivacaine trigger point injection. In this single center, double blind, randomized, cross-over trial, 18 patients with MPS received trigger point injections of either 25 units Botulinum toxin A or 0.5 ml of 0.5% bupivacaine per trigger point. A maximum of eight trigger points were injected per subject. Subjects were followed until their pain returned to 75% or more of their pre-injection pain for two consecutive weeks, after which there was a 2 week wash-out period. The subjects then crossed over and had the same trigger points injected with the other agent. All subjects participated in a home exercise program involving static stretches of the affected muscles. Both treatments were effective in reducing pain when compared to baseline (P=0.0067). There was, however, no significant difference between the BTX A and 0.5% bupivacaine groups in duration or magnitude of pain relief, function, satisfaction or cost of care (cost of injectate excluded). Considering the high cost of BTX A, bupivacaine is deemed a more cost-effective injectate for MPS.

Anesthetics, Local↗

Quantification of changes in myofascial trigger point sensitivity with the pressure algometer following passive stretch.

In order to determine the relationship between trigger point sensitivity and the referred symptoms of myofascial pain, VAS ratings of referred pain intensity and pressure algometer measures of myofascial trigger point sensitivity were taken pre and post treatment of the muscle containing the trigger point with passive stretch. The results in 20 subjects, experiencing unilateral or bilateral myofascial head and neck pain, showed that myofascial trigger point sensitivity decreases in response to passive stretch as assessed by the pressure algometer, and that trigger point sensitivity and intensity of referred pain are related.

Adult↗

Reliability of the pressure algometer as a measure of myofascial trigger point sensitivity.

Three studies are presented demonstrating the reliability of the pressure algometer as an index of myofascial trigger point sensitivity. The first study showed high reliability between and within experimenters when measuring marked trigger point locations. In study 2, significant between experimenter reliability in locating and measuring the same unmarked trigger point locations was shown, while study 3 supported the idea that trigger points are discrete points of focal tenderness within the muscle. The ability to quantify and reliably measure trigger point sensitivity opens the door to a range of clinical and research possibilities for myofascial and related musculoskeletal pain problems.

Adult↗

Intertester reliability of judgments of the presence of trigger points in patients with low back pain.

The purpose of this study was to determine the intertester reliability of assessments of the presence of trigger points in the region of the lumbar spine of patients with low back pain (LBP). A total of six trigger points described by Travell and Simons were studied. The trigger point examination procedures described by Travell and Simons were used by 12 physical therapists. Randomly paired therapists examined 50 patients for 197 trigger points. The Kappa coefficient, percent agreement, the observed proportion of positive agreement (Ppos), and the observed proportion of negative agreement (Pneg) were used to describe reliability. Kappa values ranged from .29 to .38. Percent agreement ranged from 76% to 79%. Ppos ranged from .43 to .52. The low Kappa and Ppos values suggest different therapists are unable to reliably determine when a trigger point is present in a patient with LBP. This study suggests the usefulness of examining for the presence of trigger points in patients with LBP should be questioned.

Adult↗