Effects of a calcium channel blocker on electrical activity in myofascial trigger spots of rabbits

OBJECTIVE: This study investigated the effect of a calcium channel blocking agent, verapamil, on the spontaneous electrical activity (SEA) in a myofascial trigger spot of biceps femoris muscles of rabbits. DESIGN: Left and right legs of eight adult New Zealand rabbits were randomly assigned into either experimental or control groups to assess the effect of verapamil on SEA. Verapamil and normal saline were injected into the external iliac artery for experimental and control groups, respectively. The experiment was divided into two phases: Phase A investigated the immediate effect of verapamil on SEA of one active locus, and phase B studied the effect of verapamil on SEA of 25 different active loci. The average integrated value of SEA was used to statistically analyze the effect of verapamil on myofascial trigger-spot sensitivity. RESULTS: In phase A, conducted on one active locus, the regression analysis results showed that the average integrated value in the verapamil group linearly decreased with time, but the average integrated value did not significantly change with time in the control group. In phase B, which analyzed 25 different active loci, the results indicated that the mean average integrated values in the verapamil group was significantly lower than that of the control group. CONCLUSIONS: Calcium channel blockers can effectively inhibit the SEA of myofascial trigger spots.     

Effect of botulinum toxin on endplate noise in myofascial trigger spots of rabbit skeletal muscle

OBJECTIVE: To assess the effect of botulinum toxin type A (BTX-A) on the endplate noise prevalence in rabbit myofascial trigger spots to confirm the role of excessive acetylcholine release on the pathogenesis of myofascial trigger points and to develop an objective indicator of the effectiveness of BTX-A in the treatment of myofascial trigger points. DESIGN: Eighteen adult New Zealand rabbits were divided into three groups that received a single bolus of BTX-A over a myofascial trigger spot region on one side of the biceps femoris muscle. Another 10 rabbits received multiple-point injections in a myofascial trigger spot where endplate noises were found. A control study was performed on the other side of the biceps femoris muscle. The endplate noise prevalence in a myofascial trigger spot region was assessed. RESULTS: It was found that injection of BTX-A reduced the prevalence of endplate noise. No significant differences between a single bolus injection and multiple-point injections were noted, although there was some evidence that multiple-point injections might maintain the endplate noise decreasing effect much longer than a single injection. CONCLUSIONS: This study demonstrated the suppressive effect of BTX-A on endplate noise prevalence in a myofascial trigger spot region. The prevalence of endplate noise in the myofascial trigger point region may be a useful objective indicator for evaluating the therapeutic effectiveness of BTX-A injection to treat myofascial trigger points.     

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.     

Trigger Point Needling: Techniques and Outcome

In this review we provide the updates on last years' advancements in basic science, imaging methods, efficacy, and safety of dry needling of myofascial trigger points (MTrPs). The latest studies confirmed that dry needling is an effective and safe method for the treatment of MTrPs when provided by adequately trained physicians or physical therapists. Recent basic studies have confirmed that at the site of an active MTrP there are elevated levels of inflammatory mediators, known to be associated with persistent pain states and myofascial tenderness and that this local milieu changes with the occurrence of local twitch response. Two new modalities, sonoelastography and magnetic resonance elastography, were recently introduced allowing noninvasive imaging of MTrPs. MTrP dry needling, at least partially, involves supraspinal pain control via midbrain periaqueductal gray matter activation. A recent study demonstrated that distal muscle needling reduces proximal pain by means of the diffuse noxious inhibitory control. Therefore, in a patient too sensitive to be needled in the area of the primary pain source, the treatment can be initiated with distal needling.     

Myofascial trigger points

Painful conditions of the musculoskeletal system, including myofascial pain syndrome, constitute some of the most important chronic problems encountered in a clinical practice. A myofascial trigger points is a hyperirritable spot, usually within a taut band of skeletal muscle, which is painful on compression and can give rise to characteristic referred pain, motor dysfunction, and autonomic phenomena. Trigger points may be relieved through noninvasive measures, such as spray and stretch, transcutaneous electrical stimulation, physical therapy, and massage. Invasive treatments for myofascial trigger points include injections with local anesthetics, corticosteroids, or botulism toxin or dry needling. The etiology, pathophysiology, and treatment of myofascial trigger points are addressed in this article.     

Dry needling versus friction massage to treat tension type headache: A randomized clinical trial

Tension type headache (TTH), the most common type of headache, is known to be associated with myofascial pain syndrome and the existence of myofascial trigger points. There are several treatment options for myofascial trigger points. In this study we compared the effectiveness of dry needling and friction massage to treat patients with TTH.A convenience sample of 44 patients with TTH participated in this randomized clinical trial. The frequency and intensity of headache, pressure pain threshold at the trigger point site, and cervical range of motion were recorded. Then the participants were randomly assigned to one of two treatment groups for dry needling or friction massage, delivered in 3 sessions during 1 week. The participants were evaluated 48?h after the last treatment session. Analysis of covariance, paired t-test and Wilcoxon's test were used for statistical analysis.The results showed that both treatment methods significantly reduced headache frequency and intensity, and increased pain threshold at the trigger points. However, neither treatment had any effect on cervical range of motion except for extension, which increased in the dry needling group. Between-group comparisons showed that dry needling increased pain threshold significantly more than friction massage. There were no significant differences between groups in any other outcome variables.Dry needling and friction massage were equally effective in improving symptoms in patients with TTH. The decreases in frequency and intensity of headache were similar after both dry needing and friction massage.     

Myofacial trigger point

Myofascial trigger points are one of the most common causes of acute and chronic musculoskeletal pain. Contrary to popular belief, myofascial trigger points can be primary, and not just secondary due to other non-muscular pathology. The main criteria, for which the interrater reliability has been established, include the presence of a taut band, a local twitch response, an exquisite tender point within the taut band, and typical referred pain patterns. During the past few years, the actual existence and high prevalence of myofascial trigger points are supported by worldwide research findings. The “energy crisis theory” describes the peripheral pathophysiologic events of myofascial trigger points. In most cases myofascial trigger points can be treated successfully both in acute and chronic pain syndromes. Several treatment options are available including manual therapy, injections, dry needling, and electrotherapeutic modalities. In some cases neuroplastic changes in the spinal dorsal horn and sympathetic-afferent coupling play a role in the development of chronic pain syndromes and complicate the treatment.      

Spinal cord mechanism involving the remote effects of dry needling on the irritability of myofascial trigger spots in rabbit skeletal muscle

Hsieh Y-L, Chou L-W, Joe Y-S, Hong C-Z. Spinal cord mechanism involving the remote effects of dry needling on the irritability of myofascial trigger spots in rabbit skeletal muscle.

Objective

To elucidate the neural mechanisms underlying the remote effects produced by dry needling rabbit skeletal muscle myofascial trigger spots (MTrSs) via analyses of their endplate noise (EPN) recordings.

Design

Experimental animal controlled trial.

Setting

An animal laboratory of a university.

Animals

Male New Zealand rabbits (N=96) (body weight, 2.5–3.0kg; age, 16–20wk).

Intervention

Animals received no intervention for neural interruption in group I, transection of the tibial nerve in group II, transection of L5 and L6 spinal cord in group III, and transection of the T1 and T2 spinal cord in group IV. Each group was further divided into 4 subgroups: animals received ipsilateral dry needling, contralateral dry needling, ipsilateral sham needling, or contralateral sham needling of gastrocnemius MTrSs.

Main Outcome Measures

EPN amplitudes of biceps femoris (BF) MTrSs.

Results

BF MTrS mean EPN amplitudes significantly increased (P<.05) initially after gastrocnemius verum needling but reduced to a level significantly lower (P<.05) than the preneedling level in groups I and IV with ipsilateral dry needling or contralateral dry needling, and in group II with contralateral dry needling (but not ipsilateral dry needling). No significant EPN amplitude changes were observed in BF MTrS in group III or in the control animals receiving superficial needling (sham).

Conclusion

This remote effect of dry needling depends on an intact afferent pathway from the stimulating site to the spinal cord and a normal spinal cord function at the levels corresponding to the innervation of the proximally affected muscle.     

Anesthesia (12)

A deltoid motor response is a satisfactory endpoint for successful block. (Columbia Presbyterian Medical Center, New York, NY) Reg Anesth Pain Med 2000;25:356–359. This study investigates the notion that a deltoid twitch may be just as effective as one in the biceps for predicting a successful motor block. Patients (N = 160) scheduled for shoulder surgery were studied prospectively. Interscalene blocks (ISBs) were performed using neurostimulation according to our standard technique. Twitches of the deltoid or biceps or both, whichever appeared first, were accepted and used as the endpoint for needle placement and injection of local anesthetic. Motor block success, i.e., patient inability to lift the arm against gravity, and minutes to motor block onset were recorded. Of the 160 ISBs performed, a biceps twitch was elicited in 61 patients. In 54 patients, a deltoid twitch was elicited and in 45 patients, both a biceps and deltoid contraction were elicited simultaneously. The failure rate did not differ widely among the groups; there was 1 failed motor block in the deltoid group and none in the other groups. There was no statistically significant difference in onset times between the 3 muscle twitch groups. Conclude that a deltoid twitch is as effective as a biceps twitch in determining accurate needle placement for ISB and in predicting successful motor block. Acceptance of a deltoid twitch during ISB eliminates the need for further probing and may translate into better patient acceptance and in a smaller risk of needle‐induced nerve damage. Comment by Alan David Kaye, MD, PhD. Interscalene brachial plexus block provides a valuable technique for shoulder surgery. The literature is in agreement with elicitation of paresthesias versus peripheral nerve stimulation. The literature is somewhat unclear regarding deltoid muscle versus biceps twitch as a satisfactory endpoint, prior to injection of local anesthetic. This prospective study involved 160 patients presenting for elective shoulder surgery. A biceps twitch was elicited in 61 patients; 54 had a deltoid twitch, and in 45 patients, both a biceps and deltoid twitch were elicited. There was no statistically different onset time in the 3 groups; however, the failure rate did not differ in the 3 groups either (only 1 patient in the deltoid group had a failed block). The authors conclude that a deltoid twitch is as effective as one in the biceps at ensuring a successful interscalene brachial plexus block and that repositioning is not warranted if either muscle group is elicited. The authors should be applauded for this study because it strongly suggests that essentially any elicitation of deltoid or biceps twitch will result in a highly successful and clinically useful block.     

Dry Needling for Management of Pain in the Upper Quarter and Craniofacial Region

Dry needling is a therapeutic intervention that has been growing in popularity. It is primarily used with patients that have pain of myofascial origin. This review provides background about dry needling, myofascial pain, and craniofacial pain. We summarize the evidence regarding the effectiveness of dry needling. For patients with upper quarter myofascial pain, a 2013 systematic review and meta-analysis of 12 randomized controlled studies reported that dry needling is effective in reducing pain (especially immediately after treatment) in patients with upper quarter pain. There have been fewer studies of patients with craniofacial pain and myofascial pain in other regions, but most of these studies report findings to suggest the dry needling may be helpful in reducing pain and improving other pain related variables such as the pain pressure threshold. More rigorous randomized controlled trials are clearly needed to more fully elucidate the effectiveness of dry needling.     

Dry needling of trigger points with and without paraspinal needling in myofascial pain syndromes in elderly patients

OBJECTIVES: To compare the efficacies of dry needling of trigger points (TrPs) with and without paraspinal needling in myofascial pain syndrome of elderly patients. DESIGN: Single-blinded, randomized controlled trial. SUBJECTS: Forty (40) subjects, between the ages of 63 and 90 with myofascial pain syndrome of the upper trapezius muscle. INTERVENTIONS: Eighteen (18) subjects were treated with dry needling of all the TrPs only and another 22 with additional paraspinal needling on days 0, 7, and 14. RESULTS: At 4-week follow-up the results were as follows: (1) TrP and paraspinal dry needling resulted in more continuous subjective pain reduction than TrP dry needling only; (2) TrP and paraspinal dry needling resulted in significant improvements on the geriatric depression scale but TrP dry needling only did not; (3) TrP and paraspinal dry needling resulted in improvements of all the cervical range of motions but TrP dry needling only did not in extensional cervical range of motion; and (4) no cases of gross hemorrhage were noted. CONCLUSIONS: TrP and paraspinal dry needling is suggested to be a better method than TrP dry needling only for treating myofascial pain syndrome in elderly patients.     

Effectiveness of dry needling techniques in patients with knee osteoarthritis: A systematic review and meta-analysis

BackgroundDry needling has been found to be effective in various myofascial pain syndromes and musculoskeletal conditions. However, there is a need to evaluate the effects of dry needling techniques in patients with knee osteoarthritis. Hence, the objective of this systematic review was to identify and critically review the evidence on the short-term and long-term effects of dry needling techniques in patients with knee osteoarthritis.MethodsDatabases such as Pubmed, Cochrane library, and Scopus were searched from their inception to July 2019 for randomized controlled trials using dry needling as an active intervention against control/sham/placebo treatment in patients with knee osteoarthritis. The quality of the selected studies was analyzed using Cochrane tool for assessment of risk of bias.ResultsOut of 247 studies, 9 studies were included in the review. The qualitative synthesis for myofascial trigger point dry needling showed contradictory results. The mean difference for periosteal stimulation was significant on pain and function immediately post-treatment (p < 0.00001). The mean difference for intramuscular electrical stimulation on pain was significant (p = 0.03), but marked heterogeneity was found among the studies.ConclusionGood quality studies on myofascial trigger point needling and intramuscular electrical stimulation are required to evaluate their effects in patients with knee osteoarthritis. The review demonstrates a moderate-quality evidence on the short-term effect of periosteal stimulation technique on pain and function in knee osteoarthritis. Future studies comparing the effects of various techniques of dry needling with different dosages and long-term follow up need to be conducted.     

Acupuncture and dry needling in the management of myofascial trigger point pain: A systematic review and meta‐analysis of randomised controlled trials

Pain from myofascial trigger points is often treated by needling, with or without injection, although evidence is inconclusive on whether this is effective. We aimed to review the current evidence on needling without injection, by conducting a systematic literature review.We searched electronic databases to identify relevant randomised controlled trials, and included studies where at least one group were treated by needling directly into the myofascial trigger points, and where the control was either no treatment, or usual care; indirect local dry needling or some form of placebo intervention. We extracted data on pain, using VAS scores as the standard.Seven studies were included. One study concluded that direct dry needling was superior to no intervention. Two studies, comparing direct dry needling to needling elsewhere in the muscle, produced contradictory results. Four studies used a placebo control and were included in a meta-analysis. Combining these studies (n = 134), needling was not found to be significantly superior to placebo (standardised mean difference, 14.9 [95%CI, ?5.81 to 33.99]), however marked statistical heterogeneity was present (I² = 88%).In conclusion, there is limited evidence deriving from one study that deep needling directly into myofascial trigger points has an overall treatment effect when compared with standardised care. Whilst the result of the meta-analysis of needling compared with placebo controls does not attain statistically significant, the overall direction could be compatible with a treatment effect of dry needling on myofascial trigger point pain. However, the limited sample size and poor quality of these studies highlights and supports the need for large scale, good quality placebo controlled trials in this area.     

Post-needling soreness after myofascial trigger point dry needling: Current status and future research

Post-dry needling soreness is a common complication of myofascial trigger point (MTrP) dry needling treatment. The prevention, management and relevance of this complication remain uncertain. This paper examines the current state of knowledge and suggests directions for further studies in this area. MTrPs are hypersensitive nodules in skeletal muscles' taut bands, present in several pain conditions. Dry needling has been recommended for relieving MTrP pain. MTrP dry needling procedures have shown to be associated with post-needling soreness, which is thought to be a consequence of the neuromuscular damage, and hemorrhagic and inflammatory reaction generated by the needle. Postneedling soreness is a very frequent effect after deep dry needling, usually lasting less than 72?h. It may not be especially distressing for most patients. However, patients presenting with higher levels of post-needling soreness, not perceiving dry needling effectiveness in the first session, or not having high myofascial pain intensity before treatment, could be the most likely to find post-needling soreness more distressing, functionally limiting and to abandon treatment. Future research should assess the clinical relevance of post-needling soreness. Post-needling soreness should be considered when investigating dry needling effectiveness since it could overlie the original myofascial pain and influence the patients’ pain ratings.     

Needling therapies in the management of myofascial trigger point pain: a systematic review.

OBJECTIVE: To establish whether there is evidence for or against the efficacy of needling as a treatment approach for myofascial trigger point pain. DATA SOURCES: PubMed, Ovid MEDLINE, Ovid EMBASE, the Cochrane Library, AMED, and CISCOM databases, searched from inception to July 999. STUDY SELECTION: Randomized, controlled trials in which some form of needling therapy was used to treat myofascial pain. DATA EXTRACTION: Two reviewers independently extracted data concerning trial methods, quality, and outcomes. DATA SYNTHESIS: Twenty-three papers were included. No trials were of sufficient quality or design to test the efficacy of any needling technique beyond placebo in the treatment of myofascial pain. Eight of the 10 trials comparing injection of different substances and all 7 higher quality trials found that the effect was independent of the injected substance. All 3 trials that compared dry needling with injection found no difference in effect. CONCLUSIONS: Direct needling of myofascial trigger points appears to be an effective treatment, but the hypothesis that needling therapies have efficacy beyond placebo is neither supported nor refuted by the evidence from clinical trials. Any effect of these therapies is likely because of the needle or placebo rather than the injection of either saline or active drug. Controlled trials are needed to investigate whether needling has an effect beyond placebo on myofascial trigger point pain.     

A systematic review of manual therapy techniques,dry cupping and dry needling in the reduction of myofascial pain and myofascial trigger points

IntroductionMyofascial pain with myofascial triggers are common musculoskeletal complaints. Popular treatments include manual therapy, dry needling, and dry cupping. The purpose of this systematic review was to compare the efficacy of each treatment in the short-term relief of myofascial pain and myofascial trigger points.MethodsSearch engines included Google Scholar, EBSCO Host, and PubMed. Searches were performed for each modality using the keywords myofascial pain syndrome and myofascial trigger points. The inclusion criteria included English-language, peer-reviewed journals; a diagnosis of myofascial pain syndrome or trigger points; manual therapy, dry needling, or dry cupping treatments; retrospective studies or prospective methodology; and inclusion of outcome measures.ResultsEight studies on manual therapy, twenty-three studies on dry needling, and two studies on dry cupping met the inclusion criteria. The Physiotherapy Evidence Database (PEDro) was utilized to assess the quality of all articles.DiscussionWhile there was a moderate number of randomized controlled trials supporting the use of manual therapy, the evidence for dry needling ranged from very low to moderate compared to control groups, sham interventions, or other treatments and there was a paucity of data on dry cupping. Limitations included unclear methodologies, high risk for bias, inadequate blinding, no control group, and small sample sizes.ConclusionWhile there is moderate evidence for manual therapy in myofascial pain treatment, the evidence for dry needling and cupping is not greater than placebo. Future studies should address the limitations of small sample sizes, unclear methodologies, poor blinding, and lack of control groups.     

The needle effect in the relief of myofascial pain.

In reviewing techniques for therapeutic local anaesthesia of pain spots, it appeared that the common denominator was puncture by the needle and not the anaesthetic employed. The present study examines short- and long-term effects of dry needling in the treatment of chronic myofascial pain. 241 patients and 312 pain sites were treated by needling. When the most painful spot was touched by the needle, immediate analgesia without hypesthesia was observed in 86.8% of cases. Permanent relief of tenderness in the needled structure was obtained for 92 structures; relief for several months in 58; for several weeks in 63; and for several days in 32 out of 288 pain sites followed up. The effectiveness of treatment was related to the intensity of pain produced at the trigger zone, and to the precision with which the site of maximal tenderness was located by the needle. The immediate analgesia produced by needling the pain spot has been called the "needle effect".     

Effect of Treatment on Trigger Points

Patients with muscle pain complaints commonly are seen by clinicians treating pain, especially pain of musculoskeletal origin. Myofascial trigger points merit special attention because its diagnosis requires examinations skills and its treatment requires specific techniques. If undiagnosed, the patients tend to be overinvestigated and undertreated, leading to chronic pain syndrome. Patients with myofascial pain syndrome present primarily with painful muscle(s) and restricted range of motion of the relevant joint. Palpable painful taut bands are named trigger points and are the main and pathognomonic finding on physical examination. Eliciting local twitch response and referred pain requires experience and examination skills. It may be useful to classify the patient as having acute or chronic, and as having primary or secondary, myofascial pain so the decision on the details of treatment can be curtailed to the needs of each patient. Effective treatment modalities are local heat and cold, stretching exercises, spray-and-stretch, needling, local injection, and high-power pain threshold ultrasound.     

Myofasziale Triggerpunkte

Myofascial trigger points are one of the most common causes of pain in the musculoskeletal system. They are characterized by a palpable nodule-like thickening in skeletal muscle within a taut band and a pain projection area. The etiology of myofascial trigger points is not fully understood but they are probably based on an interaction of increased local muscle tension close to neuromuscular junctions and an inflammatory component. Postural abnormalities and abnormal movement patterns also play a role. For the treatment of trigger points many techniques are available but systematic studies to prioritize or sequence the different treatment approaches are lacking. Following pragmatic considerations preference should first be given to non-invasive techniques, such as local postisometric relaxation, followed by dry needling and ultrasound. If the neurogenic inflammation component predominates the use of a local anesthetic or botulinum toxin can be considered. Each trigger point therapy should be integrated in manual-medical concepts including consideration of possible chain reactions.     

Bilateral activation of motor unit potentials with unilateral needle stimulation of active myofascial trigger points

OBJECTIVE: The objective of this study was to determine if there are electromyographic differences between active and latent myofascial trigger points (MTrPs) during trigger point needling. DESIGN: A total of 21 subjects were recruited prospectively. The experimental group consisted of 13 subjects who had active myofascial pain in the neck for >6 mos. The age-matched, control group consisted of eight subjects without neck pain but with taut bands in the cervical musculature. The active MTrPs (or latent MTrPs in the control group) were identified in the trapezius or levator scapulae muscles, then needle electrodes were inserted ipsilaterally into the muscle with the MTrPs and into the same muscle on the contralateral side. Electromyographic activity was recorded bilaterally with a dual-channel electromyographic machine, and local twitch responses were obtainedusinganacupuncturedryneedlingtechniqueonlyonthesideoftheactiveMTrPs. RESULTS: We demonstrated that in subjects with active MTrPs, bilateral motor unit activation could be obtained with unilateral needle stimulation of the trigger point. In contrast, in all the subjects with latent MTrPs, only unilateral motor unit activation could be obtained in the muscle on the same side of the needle stimulation. The motor unit potentials seen on the electromyograph were similar in morphology to a fasciculation potential but more complex. CONCLUSION: We demonstrated bilateral or mirror-image electromyographic activity associated with unilateral needle stimulation of active MTrPs. We have found no previous mention of this phenomenon in the literature. Our study supports the concept that the perpetuation of pain and muscle dysfunction in active MTrPs may be related to abnormal central nervous system processing of sensory input at the level of the spinal cord.