Bilateral Activation of Motor Unit Potentials with Unilateral Needle Stimulation of Active Myofascial Trigger Points Effects of compression at myofascial trigger points in patients with acute low back pain: A randomized controlled trial. Dry Needling to a Key Myofascial Trigger Point May Reduce the Irritability of Satellite MTrPs Effectiveness of trigger point dry needling for multiple body regions: a systematic review High prevalence of shoulder girdle muscles with myofascial trigger points in patients with shoulder pain Effectiveness of dry needling on the lower trapezius in patients with mechanical neck pain: a randomized controlled trial. Upper cervical mobility, posture and myofascial trigger points in subjects with episodic migraine: Case-control study. Interrater reliability in myofascial trigger point examination Scoping review of systematic reviews of complementary medicine for musculoskeletal and mental health conditions Active myofascial trigger points might be more frequent in patients with cervical radiculopathy.
Audette JF , Wang F , Smith H : Bilateral activation of motor unit potentialswith  unilateral needle stimulation of active myofascial trigger points . Am J Phys Med Rehabil 2004;83:368–374 . 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 prospect ively . 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 b and s 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 BACKGROUND Although there is some evidence that massage therapy , especially compression at myofascial trigger points ( MTrPs ) , is effective for sub-acute and chronic low back pain , the effectiveness of massage therapy with compression at MTrPs for acute low back pain has not been studied . METHODS To evaluate the effectiveness of compression at MTrPs for acute low back pain , 63 patients with acute low back pain were r and omly assigned to one of three groups : the MTrP group who received compression at MTrPs ( N = 23 ) , the non-MTrP group who received compression at non-trigger points ( N = 21 ) , and the effleurage massage group who received superficial massage ( N = 19 ) . The patients received the assigned treatment 3 times/week for 2 weeks . The subjective pain intensity in static and dynamic conditions and disability caused by low back pain were measured by the visual analogue scale ( VAS ) and Rol and -Morris question naire ( RMQ ) , respectively ; along with the range of motion ( ROM ) at the lumbar region and pressure pain threshold ( PPT ) at trigger points before treatment ( baseline ) , 1 week after the start of treatment , and 1 month after the end of treatment ( follow-up ) . RESULTS Static and dynamic VAS score , PPT and ROM were significantly improved in the MTrP group compared with those in the non-MTrP and effleurage groups . CONCLUSIONS These results indicate that compression at MTrPs is effective to treat acute low back pain compared with compression at non-MTrPs and superficial massage . For this article , a commentary is available at the Wiley Online Library Hsieh Y-L , Kao M-J , Kuan T-S , Chen S-M , Chen J-T , Hong C-Z : Dry needling to a key myofascial trigger point may reduce the irritability of satellite myofascial trigger points . Am J Phys Med Rehabil 2007;86:397–403 . Objective : To investigate the changes in pressure pain threshold of the secondary ( satellite ) myofascial trigger points ( MTrPs ) after dry needling of a primary ( key ) active MTrP. Design : Single blinded within-subject design , with the same subjects serving as their own controls ( r and omized ) . Fourteen patients with bilateral shoulder pain and active MTrPs in bilateral infraspinatus muscles were involved . An MTrP in the infraspinatus muscle on a r and omly selected side was dry needled , and the MTrP on the contralateral side was not ( control ) . Shoulder pain intensity , range of motion ( ROM ) of shoulder internal rotation , and pressure pain threshold of the MTrPs in the infraspinatus , anterior deltoid , and extensor carpi radialis longus muscles were measured in both sides before and immediately after dry needling . Results : Both active and passive ROM of shoulder internal rotation , and the pressure pain threshold of MTrPs on the treated side , were significantly increased ( P < 0.01 ) , and the pain intensity of the treated shoulder was significantly reduced ( P < 0.001 ) after dry needling . However , there were no significant changes in all parameters in the control ( untreated ) side . Percent changes in the data after needling were also analyzed . For every parameter , the percent change was significantly higher in the treated side than in the control side . Conclusions : This study provides evidence that dry needle – evoked inactivation of a primary ( key ) MTrP inhibits the activity in satellite MTrPs situated in its zone of pain referral . This supports the concept that activity in a primary MTrP leads to the development of activity in satellite MTrPs and the suggested spinal cord mechanism responsible for this phenomenon Background : Trigger point dry needling ( TDN ) is commonly used to treat musculoskeletal pain related to myofascial trigger points ( MTrPs ) . To date , no systematic review of high- quality r and omised controlled trials ( RCTs ) investigating TDN to multiple body regions exists . Purpose : The aim of this review is to determine the effectiveness of TDN based on high- quality RCTs for all body regions . Methods : To ensure thorough reporting , Preferred Reporting Items for Systematic Review s and Meta-Analyses ( PRISMA ) guidelines were followed as the method ological basis for this systematic review . PubMed , Physiotherapy Evidence Data base ( PEDro ) , Cinahl , Cochrane and reference lists were search ed for the years 2000–2014 and the terms ‘ TDN ’ , ‘ dry needling NOT trigger point ’ , ‘ functional dry needling ’ and ‘ intramuscular manual therapy ’ . Inclusion criteria : RCTs with PEDro scores 6–10 investigating TDN . Exclusion criteria : duplicates , non-human participants , non-English language , exclusive focus on acupuncture or medicinal injections . Three investigators search ed data bases , applied criteria , read and assigned PEDro scores to every RCT . Nineteen studies met the criteria . As compared to either baseline or control groups , significant differences were found for pain ( 14 studies ) , range of motion ( ROM ) ( five studies ) and at least one item on function and quality of life measures ( six studies ) . Limitations : This review was limited by inclusion criteria , timeframe , language and data bases search ed . Conclusion : The majority of high- quality studies included in this review show measured benefit from TDN for MTrPs in multiple body areas , suggesting broad applicability of TDN treatment for multiple muscle groups . Further high- quality research is warranted to st and ardise TDN methods to determine clinical applicability Background Shoulder pain is reported to be highly prevalent and tends to be recurrent or persistent despite medical treatment . The pathophysiological mechanisms of shoulder pain are poorly understood . Furthermore , there is little evidence supporting the effectiveness of current treatment protocol s. Although myofascial trigger points ( MTrPs ) are rarely mentioned in relation to shoulder pain , they may present an alternative underlying mechanism , which would provide new treatment targets through MTrP inactivation . While previous research has demonstrated that trained physiotherapists can reliably identify MTrPs in patients with shoulder pain , the percentage of patients who actually have MTrPs remains unclear . The aim of this observational study was to assess the prevalence of muscles with MTrPs and the association between MTrPs and the severity of pain and functioning in patients with chronic non-traumatic unilateral shoulder pain . Methods An observational study was conducted . Subjects were recruited from patients participating in a controlled trial study ing the effectiveness of physical therapy on patients with unilateral non-traumatic shoulder pain .  Sociodemographic and patient-reported symptom scores , including the Disabilities of the Arm , Shoulder , and H and ( DASH ) Question naire , and Visual Analogue Scales for Pain were compared with other studies . To test for differences in age , gender distribution , and education level between the current study population and the population s from Dutch shoulder studies , the one sample T-test was used . One observer examined all subjects ( n = 72 ) for the presence of MTrPs . Frequency distributions , means , medians , st and ard deviations , and 95 % confidence intervals were calculated for descriptive purpose s. The Spearman 's rank-order correlation ( ρ ) was used to test for association between variables . Results MTrPs were identified in all subjects . The median number of muscles with MTrPs per subject was 6 ( active MTrPs ) and 4 ( latent MTrPs ) . Active MTrPs were most prevalent in the infraspinatus ( 77 % ) and the upper trapezius muscles ( 58 % ) , whereas latent MTrPs were most prevalent in the teres major ( 49 % ) and anterior deltoid muscles ( 38 % ) . The number of muscles with active MTrPs was only moderately correlated with the DASH score . Conclusion The prevalence of muscles containing active and latent MTrPs in a sample of patients with chronic non-traumatic shoulder pain was high OBJECTIVE To evaluate the effect of dry needling into a myofascial trigger point ( MTrP ) in the lower trapezius muscle of patients with mechanical idiopathic neck pain . DESIGN A single-center , r and omized , double-blinded controlled study . SETTING Patients were recruited from the student population of a local hospital by advertisement in the university clinic from January 2010 to December 2011 . PARTICIPANTS Patients ( N=72 ) with unilateral neck pain , neck pain for ≥3 months , and active trigger points in the lower trapezius muscle were r and omly assigned to 1 of 2 treatment groups . All the patients completed the study . INTERVENTIONS Dry needling in an MTrP in the lower trapezius muscle , or dry needling in the lower trapezius muscle but not at an MTrP. MAIN OUTCOME MEASURES The visual analog scale ( VAS ) , Neck Pain Question naire ( NPQ ) , and pressure-pain threshold ( PPT ) were assessed before the intervention and 1 week and 1 month postintervention . RESULTS Treatment with dry needling of the lower trapezius muscle close to the MTrP showed decreases in pain and PPT as well as an improvement in the degree of disability ( P<.001 ) compared with the baseline and control group measurements ( P<.001 ) . The dry-needling technique performed in the MTrP showed more significant therapeutic effects ( P<.001 ) . CONCLUSIONS The application of dry needling into an active MTrP of the lower trapezius muscle induces significant changes in the VAS , NPQ , and PPT levels compared with the application of dry needling in other locations of the same muscle in patients with mechanical neck pain OBJECTIVES To evaluate the association between episodic migraines and the prevalence of myofascial trigger points ( MTrPs ) in the sternocleidomastoid and upper trapezius , forward head posture ( FHP ) , neck range of motion ( ROM ) and cervical facet joint stiffness . METHODS 20 physiotherapy students with episodic migraines and 20 age- and sex matched healthy controls were included in this observational case-control study . Demographics and headache status were evaluated through question naires . Active neck ROM , presence of MTrPs , and cervical facet joint mobility were assessed by physical examination . FHP was measured using a lateral digital photograph taken in a sitting position . RESULTS No significant differences were found in neck ROM measurements and FHP between the migraine and control groups . Significant differences were found in the prevalence of cervical facet joints stiffness in Occiput-C1 ( χ(2 ) = 4.444 , p = 0.035 ) and C1-C2 ( χ(2 ) = 10.157 , p = 0.001 ) , but not in other segments . Significant differences were found in the prevalence of active and latent MTrPs between the migraine and control subjects in the right trapezius ( χ(2 ) = 11.649 , p = 0.003 ) and right sternocleidomastoid ( χ(2 ) = 8.485 , p = 0.014 ) . CONCLUSIONS Our findings support the hypothesis that the prevalence of MTrPs in neck muscles and hypomobility in the upper cervical facet joints are associated with migraines Abstract The myofascial trigger point ( MTrP ) is the hallmark physical finding of the myofascial pain syndrome ( MPS ) . The MTrP itself is characterized by distinctive physical features that include a tender point in a taut b and of muscle , a local twitch response ( LTR ) to mechanical stimulation , a pain referral pattern characteristic of trigger points of specific areas in each muscle , and the reproduction of the patient 's usual pain . No prior study has demonstrated that these physical features are reproducible among different examiners , thereby establishing the reliability of the physical examination in the diagnosis of the MPS . This paper reports an initial attempt to establish the interrater reliability of the trigger point examination that failed , and a second study by the same examiners that included a training period and that successfully established interrater reliability in the diagnosis of the MTrP. The study also showed that the interrater reliability of different features varies , the LTR being the most difficult , and that the interrater reliability of the identification of MTrP features among different muscles also varies Objective To identify potentially effective complementary approaches for musculoskeletal (MSK)–mental health ( MH ) comorbidity , by synthesis ing evidence on effectiveness , cost-effectiveness and safety from systematic review s ( SRs ) . Design Scoping review of SRs . Methods We search ed literature data bases , registries and reference lists , and contacted key authors and professional organisations to identify SRs of r and omised controlled trials for complementary medicine for MSK or MH . Inclusion criteria were : published after 2004 , study ing adults , in English and scoring > 50 % on Assessing the Method ological Quality of Systematic Review s ( AMSTAR ) ; quality appraisal checklist ) . SRs were synthesis ed to identify research priorities , based on moderate/good quality evidence , sample size and indication of cost-effectiveness and safety . Results We included 84 MSK SRs and 27 MH SRs . Only one focused on MSK – MH comorbidity . Meditative approaches and yoga may improve MH outcomes in MSK population s. Yoga and tai chi had moderate/good evidence for MSK and MH conditions . SRs reported moderate/good quality evidence ( any comparator ) in a moderate/large population for :  low back pain ( LBP )  ( yoga , acupuncture , spinal manipulation/mobilisation , osteopathy ) , osteoarthritis ( OA ) ( acupuncture , tai chi ) , neck pain  ( acupuncture , manipulation/manual therapy ) , myofascial trigger point pain ( acupuncture ) , depression ( mindfulness-based stress reduction ( MBSR ) , meditation , tai chi , relaxation ) , anxiety ( meditation/MBSR , moving meditation , yoga ) , sleep disorders ( meditative/mind – body movement ) and stress/distress ( mindfulness ) . The majority of these complementary approaches had some evidence of safety — only three had evidence of harm . There was some evidence of cost-effectiveness for spinal manipulation/mobilisation and acupuncture for LBP , and manual therapy/manipulation for neck pain , but few SRs review ed cost-effectiveness and many found no data . Conclusions Only one SR studied MSK – MH comorbidity . Research priorities for complementary medicine for both MSK and MH ( LBP , OA , depression , anxiety and sleep problems ) are yoga , mindfulness and tai chi . Despite the large number of SRs and the prevalence of comorbidity , more high- quality , large r and omised controlled trials in comorbid population s are needed BACKGROUND Myofascial trigger points ( MTrPs ) are commonly observed in the neck , parascapular region , and upper back muscles of patients with cervical pathology . AIM To assess the frequency of latent and active myofascial trigger point ( aMTrP ) in the neck and upper back muscles in patients with cervical radiculopathy and healthy subjects . DESIGN Controlled clinical trials . SETTING Out patients and controls . POPULATION Two hundred and forty four patients and 122 controls METHODS The patients clinical ly diagnosed as cervical radiculopathy with positive Spurling 's test and confirmed by MRI , were enrolled in this study . All subjects were examined for active and latent MTrP. In patients with cervical radiculopathy , an aMTrP was distinguished from a latent one when the referred pain elicited by exploration of the MTrP is recognized as familiar . RESULTS The patients comprised of 128 female ( 52.5 % ) and 116 male ( 47.5 % ) patients . Mean age was 44.58(20 - 65 years ) . In 125 ( 51.2 % ) of patients with cervical radiculopathy were found an aMTrP at least one muscle from upper trapezius , multifidus , splenius capitis , levator scapulae , rhomboid major , minor and deep paraspinal muscles . Number and distribution of MTrPs in patients with 244 cervical radiculopathy and in healthy controls .  aMTrPs were detected most common in levator scapula ( 16.3 % ) , splenius capitis ( 14.7 % ) , rhomboid minor ( 14.3 % ) , upper part of trapezius ( 13.5 % ) , rhomboid major ( 10.2 % ) and multifidus ( 8.6 % ) muscles . Patients with cervical radiculopathy showed latent MTrP in levator scapula ( 27 % ) , splenius capitis ( 16.8 % ) , rhomboid minor ( 24.6 % ) , upper part of trapezius ( 33.2 % ) , rhomboid major ( 9 % ) and multifidus ( 8.2 % ) muscles . There was significant difference in terms of distribution of active and latent MTrPs in patients with cervical radiculopathy ( P=0.019 ) . Number of latent MTrPs in upper trapezius muscles in patients with cervical radiculopathy was more than the expected distribution . None of the subjects of control group had aMTrP. However , healthy controls showed latent MTrP in levator scapula ( 33.6 % ) , splenius capitis ( 16.4 % ) , rhomboid minor ( 21.3 % ) , upper part of trapezius ( 40.2 % ) , rhomboid major ( 6.5 % ) and multifidus ( 17.2 % ) muscles . There was no significant difference in terms of distribution of latent MTrPs between cervical radiculopathy and control groups ( P=0.249 ) . The frequency of aMTrP was found to be significantly higher in CDH with median localization as compared to posterolateral herniations ( P=0.041 ) . After conservative treatment for two weeks , number of patients with active MTrP in cervical radiculopathy were decreased about 50 % . CONCLUSION Cervical root compression would be considered as the starting or maintaining factor of aMTrP. CLINICAL REHABILITATION IMPACT The treatment of cervical radiculopathy might be facilitated the improving in aMTrPs located in aforementioned muscles
Within spinal pain , patients with neck pain were found to have the highest prevalence rates of MTrPs .
The trapezius descendens , levator scapulae , and suboccipitales muscles were the most prevalent locations for active MTrPs in patients with neck pain .
Latent MTrPs were present in asymptomatic people , but no significant differences were found in the prevalence rate of latent MTrPs between patients with spinal ( neck ) pain and healthy controls .
The only study investigating prevalence of MTrPs in different localizations of the same muscle reported no significant differences in prevalence between active and latent MTrPs within the trapezius descendens muscle .
Studies examining pathophysiological mechanisms underlying MTrPs demonstrated an acidic environment , high concentration of algogenic/inflammatory substances , stiffer muscle tissue , retro grade diastolic blood flows , spontaneous muscle activity at rest , and loss of muscle contractibility in muscles with MTrPs .
Altered central processing was also found to play a role in the development of MTrPs .
Myofascial trigger points are a prevalent clinical entity , especially in patients with neck pain .
Evidence was not found to support or deny the role of MTrPs in other spinal pain .
Compelling evidence supports local mechanisms underlying MTrPs .
OBJECTIVE A systematic review was performed to evaluate the existing evidence related to the prevalence , incidence , localization , and pathophysiology of myofascial trigger points ( MTrPs ) in patients with spinal ( back and neck ) pain .