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. Fu's subcutaneous needling: possible clinical evidence of the subcutaneous connective tissue in acupuncture. Dry Needling Alters Trigger Points in the Upper Trapezius Muscle and Reduces Pain in Subjects With Chronic Myofascial Pain. Prevalence of myofascial trigger points in the hip in patellofemoral pain. An in vivo microanalytical technique for measuring the local biochemical milieu of human skeletal muscle. Dry Needling on the Infraspinatus Latent and Active Myofascial Trigger Points in Older Adults With Nonspecific Shoulder Pain: A Randomized Clinical Trial Immediate Effects of Core-Stability Exercises and Clinical Massage on Dynamic-Balance Performance of Patients With Chronic Specific Low Back Pain. Immediate Effects of Core-Stability Exercises and Clinical Massage on Dynamic-Balance Performance of Patients With Chronic Specific Low Back Pain. Contributions of myofascial pain in diagnosis and treatment of shoulder pain. A randomized control trial Myofascial Trigger Point-focused Head and Neck Massage for Recurrent Tension-type Headache: A Randomized, Placebo-controlled Clinical Trial Induction of muscle cramps by nociceptive stimulation of latent myofascial trigger points Proximal myofascial dysfunction in complex regional pain syndrome: a retrospective prevalence study. Diagnostic utility of facet (zygapophysial) joint injections in chronic spinal pain: a systematic review of evidence. Neurophysiological and clinical effects of dry needling in patients with upper trapezius myofascial trigger points.
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 OBJECTIVES Recently it was reported that the loose connective tissue in the subcutaneous layer rapidly responded to mechanical forces evoked by acupuncture , massage , and normal physical movements . However , there were no clinical studies to substantiate these findings so far . Fu 's Subcutaneous Needling ( FSN ) is the innovative needling strategy acting specifically in the subcutaneous layer . A single-blinded and r and omized trial was design ed to compare the immediate effects of FSN with different needling directions on myofascial trigger points ( MTrP ) in the neck . DESIGN For simplicity , we chose two mutually perpendicular needle directions in this study . In one group , the needle was along the local muscle fibers and pointed to the MTrP ( Along Group ) . In the other group , the needle was across the local muscle fibers and also pointed to the MTrP ( Across Group ) . SUBJECTS Forty-seven ( 47 ) patients were r and omly divided into two groups : the Along Group ( n = 22 ) and the Across Group ( n = 25 ) . There were no significant differences with respect to age , duration of pain , and gender between the two groups . INTERVENTIONS FSN needles were inserted and swayed in the subcutaneous layer 200 times in 2 minutes . RESULTS Before and after FSN treatment , patients were subjected to the assessment of the following three parameters : motion-related pain , pain under pressure , and the range of cervical movement . Three parameters were all reduced after the FSN intervention . There were no significant differences in variation of the three parameters between the two groups . CONCLUSION Immediate effects of FSN on alleviating MTrP in the neck were not relevant to the needling directions OBJECTIVE To determine whether dry needling of an active myofascial trigger point ( MTrP ) reduces pain and alters the status of the trigger point to either a non-spontaneously tender nodule or its resolution . DESIGN A prospect i ve , nonr and omized , controlled , interventional clinical study . SETTING University campus . PARTICIPANTS A total of 56 subjects with neck or shoulder girdle pain of more than 3 months duration and active MTrPs were recruited from a campus-wide volunteer sample . Of these , 52 completed the study ( 23 male and 33 female ) . Their mean age was 35.8 years . INTERVENTIONS Three weekly dry needling treatments of a single active MTrP. MAIN OUTCOME MEASURES PRIMARY OUTCOMES Baseline and posttreatment evaluations of pain using a verbal analogue scale , the Brief Pain Inventory , and the status of the MTrP as determined by digital palpation . Trigger points were rated as active ( spontaneously painful ) , latent ( requiring palpation to reproduce the characteristic pain ) , or resolved ( no palpable nodule ) . SECONDARY OUTCOMES Profile of Mood States , Oswestry Disability Index , and Short Form 36 scores , and cervical range of motion . RESULTS PRIMARY OUTCOMES A total of 41 subjects had a change in trigger point status from active to latent or resolved , and 11 subjects had no change ( P < .001 ) . Reduction in all pain scores was significant ( P < .001 ) . SECONDARY OUTCOMES Significant improvement in posttreatment cervical rotational asymmetry in subjects as follows : unilateral/bilateral MTrPs ( P = .001 and P = 21 , respectively ) ; in pain pressure threshold in subjects with unilateral/bilateral MTrPs , ( P = .006 and P = .012 , respectively ) ; improvement in the SF-36 mental health and physical functioning subscale scores ( P = .019 and P = .03 ) , respectively ; and a decrease in the Oswestry Disability Index score ( P = .003 ) . CONCLUSIONS Dry needling reduces pain and changes MTrP status . Change in trigger point status is associated with a statistically and clinical ly significant reduction in pain . Reduction of pain is associated with improved mood , function , and level of disability OBJECTIVES To determine the prevalence of myofascial trigger points ( MTrPs ) in the gluteus medius ( GMe ) and quadratus lumborum ( QL ) for subjects with patellofemoral pain ( PFP ) , and to examine the relationship between MTrPs and force production of the GMe after treatment . DESIGN R and omized controlled trial . SETTING A physical therapy clinic . PARTICIPANTS Subjects ( N=52 ; mean age ± SD , 30±12y ; mean height ± SD , 172±10 cm ; mean mass ± SD , 69±14 kg ) volunteered and were divided into 2 groups : a PFP group ( n=26 ) consisting of subjects with PFP , and a control group ( n=26 ) with no history of PFP .  INTERVENTIONS Patients with PFP received trigger point pressure release therapy ( TPPRT ) . MAIN OUTCOME MEASURES Hip abduction isometric strength and the presence of MTrPs . RESULTS Prevalence of bilateral GMe and QL MTrPs for the PFP group was significantly higher compared with controls ( P=.001 ) . Subjects in the PFP group displayed significantly less hip abduction strength compared with the control group ( P=.007 ) . However , TPPRT did not result in increased force production . CONCLUSIONS Subjects with PFP have a higher prevalence of MTrPs in bilateral GMe and QL muscles . They demonstrate less hip abduction strength compared with controls , but the TPPRT did not result in an increase in hip abduction strength Myofascial pain associated with myofascial trigger points ( MTrPs ) is a common cause of nonarticular musculoskeletal pain . Although the presence of MTrPs can be determined by soft tissue palpation , little is known about the mechanisms and biochemical milieu associated with persistent muscle pain . A microanalytical system was developed to measure the in vivo biochemical milieu of muscle in near real time at the subnanogram level of concentration . The system includes a microdialysis needle capable of continuously collecting extremely small sample s ( approximately 0.5 microl ) of physiological saline after exposure to the internal tissue milieu across a 105-microm-thick semi-permeable membrane . This membrane is positioned 200 microm from the tip of the needle and permits solutes of < 75 kDa to diffuse across it . Three subjects were selected from each of three groups ( total 9 subjects ) : normal ( no neck pain , no MTrP ) ; latent ( no neck pain , MTrP present ) ; active ( neck pain , MTrP present ) . The microdialysis needle was inserted in a st and ardized location in the upper trapezius muscle . Due to the extremely small sample size collected by the microdialysis system , an established microanalytical laboratory , employing immunoaffinity capillary electrophoresis and capillary electrochromatography , performed analysis of selected analytes . Concentrations of protons , bradykinin , calcitonin gene-related peptide , substance P , tumor necrosis factor-alpha , interleukin-1beta , serotonin , and norepinephrine were found to be significantly higher in the active group than either of the other two groups ( P < 0.01 ) . pH was significantly lower in the active group than the other two groups ( P < 0.03 ) . In conclusion , the described microanalytical technique enables continuous sampling of extremely small quantities of substances directly from soft tissue , with minimal system perturbation and without harmful effects on subjects . The measured levels of analytes can be used to distinguish clinical ly distinct groups Background and Purpose : Shoulder pain is a prevalent condition in older adults . Some authors associate nonspecific shoulder pain with myofascial trigger points ( MTrPs ) in the infraspinatus muscle . Dry needling is recommended to relieve the MTrP pain of shoulders in the short term ( < 9 days ) . Active MTrPs dry needling improves shoulder pain and the irritability of the satellite MTrPs in the referred pain area . Nociceptive activity at a latent MTrP may influence motor activity and the sensitivity of MTrPs in distant muscles at a similar segmental level . Therefore , this study aim ed to evaluate dry needling on 1 latent MTrP , in conjunction with 1 active MTrP , in the infraspinatus muscle of older adults with nonspecific shoulder pain . Methods : A single-center , r and omized , single-blinded , controlled study ( NCT02032602 ) was carried out . Sixty-six patients aged 65 years and older with trigger points in the ipsilateral infraspinatus of the painful shoulder were r and omly assigned to ( 1 ) of ( 2 ) treatment groups . A session of dry needling on the infraspinatus was performed in ( 1 ) the most hyperalgesic active and latent MTrP or ( 2 ) only the most hyperalgesic active MTrP. The Numeric Rating Scale , the pressure pain threshold ( primary outcome ) on the anterior deltoid and extensor carpi radialis brevis latent MTrPs , and grip strength were assessed before , after , and 1 week after the intervention . Results : Statistically significant differences in the reduction of pain intensity ( P ⩽ .001 ; & eegr;2 = 0.159 - 0.269 ; d = 1.017 - 1.219 ) and the increase of pressure pain threshold ( P < .001 ; & eegr;2 = 0.206 - 0.481 ; d = 0.870 - 1.924 ) were found for the ( 1 ) treatment group immediately and 1 week postintervention . Nevertheless , no statistical significant differences were found in grip strength ( P > . 05 ; & eegr;2 = 0.006 - 0.033 ; d = 0.158 - 0.368 ) . Conclusions : One dry needling intervention of the latent MTrP associated with the key active MTrP of the infraspinatus reduces pain intensity and the irritability of the satellite MTrPs located in the referred pain area in the short term in older adults with nonspecific shoulder pain CONTEXT Previous studies showed improved dynamic-balance ( DB ) performance after core-stability ( CS ) exercises in population s with chronic low back pain . Although clinical massage plus exercise is likely to better enhance analgesia than exercise alone , its efficacy on balance remains unclear . OBJECTIVE To evaluate the immediate effects of CS exercises plus myofascial trigger-point ( MTrP ) therapy in comparison with CS exercises alone on DB performance , pressure-pain threshold ( PPT ) , and cross-sectional area of active MTrPs in patients with clinical instability of the lumbar spine and chronic myofascial pain syndrome . DESIGN R and omized , assessor-blind , test-retest . SETTING University research laboratory . PATIENTS 10 physically active adults ( 5 men , 5 women ) . MAIN OUTCOME MEASURES Single-leg DB performance and side-to-side ratios in 2 planes of motion ( frontal , sagittal ) , as well as PPT and cross-sectional area of active MTrPs , were measured using stabilometry , pressure algometry , and real-time ultrasound scanning , respectively . INTERVENTIONS The 1st group performed CS exercises alone , whereas the same exercise program was applied in the 2nd group plus cross-fiber friction on active MTrPs ( 3.5 min/MTrP ) . RESULTS Within-group statistically and clinical ly significant differences were observed only for group II in PPT . However , group I also exhibited a large effect size with clinical ly significant changes from baseline on this outcome . Furthermore , patients in group II clinical ly improved their balance ratios and differed from group I at posttest in sagittal-plane DB performance of the painful side . CONCLUSION CS exercises immediately increase the PPT of active MTrPs in physically active adults with clinical instability of the lumbar spine and chronic myofascial pain syndrome . When MTrP therapy is added , side-to-side asymmetries in DB are minimized CONTEXT Previous studies showed improved dynamic-balance ( DB ) performance after core-stability ( CS ) exercises in population s with chronic low back pain . Although clinical massage plus exercise is likely to better enhance analgesia than exercise alone , its efficacy on balance remains unclear . OBJECTIVE To evaluate the immediate effects of CS exercises plus myofascial trigger-point ( MTrP ) therapy in comparison with CS exercises alone on DB performance , pressure-pain threshold ( PPT ) , and cross-sectional area of active MTrPs in patients with clinical instability of the lumbar spine and chronic myofascial pain syndrome . DESIGN R and omized , assessor-blind , test-retest . SETTING University research laboratory . PATIENTS 10 physically active adults ( 5 men , 5 women ) . MAIN OUTCOME MEASURES Single-leg DB performance and side-to-side ratios in 2 planes of motion ( frontal , sagittal ) , as well as PPT and cross-sectional area of active MTrPs , were measured using stabilometry , pressure algometry , and real-time ultrasound scanning , respectively . INTERVENTIONS The 1st group performed CS exercises alone , whereas the same exercise program was applied in the 2nd group plus cross-fiber friction on active MTrPs ( 3.5 min/MTrP ) . RESULTS Within-group statistically and clinical ly significant differences were observed only for group II in PPT . However , group I also exhibited a large effect size with clinical ly significant changes from baseline on this outcome . Furthermore , patients in group II clinical ly improved their balance ratios and differed from group I at posttest in sagittal-plane DB performance of the painful side . CONCLUSION CS exercises immediately increase the PPT of active MTrPs in physically active adults with clinical instability of the lumbar spine and chronic myofascial pain syndrome . When MTrP therapy is added , side-to-side asymmetries in DB are minimized Background Rotator cuff tendinopathy and subacromial impingement syndrome present complex patomechanical situations , frequent difficulties in clinical diagnosis and lack of effectiveness in treatment . Based on clinical experience , we have therefore considered the existence of another pathological entity as the possible origin of pain and dysfunction . The hypothesis of this study is to relate subacromial impingement syndrome ( SIS ) with myofascial pain syndrome ( MPS ) , since myofascial trigger points ( MTrPs ) cause pain , functional limitation , lack of coordination and alterations in quality of movement , even prior to a tendinopathy . MTrPs can coexist with any degenerative subacromial condition . If they are not taken into consideration , they could perpetuate and aggravate the problem , hindering diagnosis and making the applied treatments ineffective . The aims and methods of this study are related with providing evidence of the relationship that may exist between this condition and MPS in the diagnosis and treatment of rotator cuff tendonitis and /or SIS . Method / design A descriptive transversal study will be made to find the correlation between the diagnosis of SIS and rotator cuff tendonitis , positive provocation test responses , the existence of active MTrPs and the results obtained with ultrasonography ( US ) and Magnetic Renonance Imaging ( MRI ) . A r and omized double blinded clinical trial will be carried out in experimental conditions : A Protocol ized treatment based on active and passive joint repositioning , stabilization exercises , stretching of the periarticular shoulder muscles and postural reeducation . B. The previously described protocol ized treatment , with the addition of dry needling applied to active MTrPs with the purpose of isolating the efficacy of dry needling in treatment . Discussion This study aims to provide a new vision of shoulder pain , from the perspective of MPS . This syndrome can , by itself , account for shoulder pain and dysfunction , although it can coexist with real conditions involving the tendons . Trail Registration IS RCT N Number : Objective : Myofascial trigger points ( MTrPs ) are focal disruptions in the skeletal muscle that can refer pain to the head and reproduce the pain patterns of tension-type HA ( TTH ) . The present study applied massage focused on MTrPs of patients with TTH in a placebo-controlled , clinical trial to assess efficacy on reducing headache ( HA ) pain . Methods : Fifty-six patients with TTH were r and omized to receive 12 massage or placebo ( detuned ultrasound ) sessions over 6 weeks , or to wait-list . Trigger point release massage focused on MTrPs in cervical musculature . HA pain ( frequency , intensity , and duration ) was recorded in a daily HA diary . Additional outcome measures included self-report of perceived clinical change in HA pain and pressure-pain threshold at MTrPs in the upper trapezius and suboccipital muscles . Results : From diary recordings , group differences across time were detected in HA frequency ( P=0.026 ) , but not for intensity or duration . Post hoc analysis indicated that HA frequency decreased from baseline for both massage ( P<0.0003 ) and placebo ( P=0.013 ) , but no difference was detected between massage and placebo . Patient report of perceived clinical change was greater reduction in HA pain for massage than placebo or wait-list groups ( P=0.002 ) . Pressure-pain threshold improved in all muscles tested for massage only ( all P’s<0.002 ) . Discussion : Two findings from this study are apparent : ( 1 ) MTrPs are important components in the treatment of TTH , and ( 2 ) TTH , like other chronic conditions , is responsive to placebo . Clinical trials on HA that do not include a placebo group are at risk for overestimating the specific contribution from the active intervention The aim of this present study is to test the hypothesis that nociceptive stimulation of latent myofascial trigger points ( MTrPs ) increases the occurrence of local muscle cramps . Nociceptive muscle stimulation was obtained by a bolus injection of glutamate ( 0.1 ml , 0.5 M ) into a latent MTrP and a control point ( a non-MTrP ) located in the right or left gastrocnemius medialis muscles in 14 healthy subjects . A bolus of isotonic saline ( 0.9 % , 0.1 ml ) injection served as a control . The injections were guided by intramuscular electromyography ( EMG ) showing resting spontaneous electrical activity at a latent MTrP and no such activity at a non-MTrP. Intramuscular and surface EMG activities in the gastrocnemius medialis muscle were recorded pre- , during- , and post-injection for a period of 8 min to monitor the occurrence of muscle cramps , which are characterized by a brief episodic burst of high levels of EMG activity . The results showed that glutamate and isotonic saline injections into the latent MTrPs induced higher peak pain intensity than into the non-MTrPs ( both P < 0.05 ) . Glutamate injection induced higher peak pain intensity than isotonic saline injection into either latent MTrPs or non-MTrPs ( both P < 0.05 ) . Muscle camps were observed in 92.86 % of the subjects following glutamate injection into the latent MTrPs , but not into the non-MTrPs ( P < 0.001 ) . No muscle cramps were recorded following isotonic saline injection into either the latent MTrPs or the non-MTrPs . These results suggest that latent MTrPs could be involved in the genesis of muscle cramps . Focal increase in nociceptive sensitivity at MTrPs constitutes one of the mechanisms underlying muscle cramps OBJECTIVE To assess the prevalence of clinical ly evident myofascial dysfunction ( MD ) and its relationship to motor neglect ( MN ) in Complex Regional Pain Syndrome ( CRPS ) . DESIGN Retrospective chart review . PATIENTS Forty-one consecutively evaluated CRPS patients . OUTCOME MEASURES ( a ) Prevalence of trigger points in the proximal musculature of the CRPS limb . ( b ) Prevalence of MN in a subset ( n = 34 ) . RESULTS MD was detected in 61 % of CRPS patients . It was more prevalent in the upper limb ( 70 % ) than in the lower limb ( 47 % ) . MN was more common in those who also had MD . CONCLUSION MD is common in CRPS patients , especially in the upper limb and in those patients with MN . Prospect i ve trials are needed to confirm these intriguing findings , which may have important implication s regarding CRPS pathophysiology and treatment BACKGROUND Chronic refractory spinal pain poses a peculiar diagnostic challenge because of multiple putative pain sources , overlapping clinical features , and nonspecific radiologic findings . Diagnostic injection techniques are employed to isolate the source ( s ) of pain . Facet or zygapophysial joint pain is an example of spinal pain diagnosed by local anesthetic injections of the facet joint or its nerve supply . Diagnostic facet joint injections are expected to meet the cardinal features of a diagnostic test ( i.e. , accuracy , safety and reproducibility ) . Accuracy must be compared with a " gold " or criterion st and ard that can confirm presence or absence of a disease . There is , however , no available gold st and ard , such as biopsy , to measure presence or absence of pain . Hence , there is a degree of uncertainty concerning the accuracy of diagnostic facet joint injections . OBJECTIVES To evaluate accuracy , safety and reproducibility of facet or zygapophysial joint injections in diagnosing chronic spinal pain of facet joint origin . STUDY DESIGN A systematic review of the literature for clinical studies on efficacy and utility of facet joint/nerve injections in diagnosing spinal pain from facet joints . METHODS Relevant literature on diagnostic facet injections was identified through data base search es . Excluded were abstract s , review s , book chapters , case reports and studies based on single blocks or blocks without radiologic control . Prospect i ve studies with placebo control , or controlled comparative local anesthetic blocks , were given priority over retrospective studies . Each study was grade d using AHRQ and QUADAS criteria . The level of evidence was classified as conclusive , strong , moderate , limited , or inconclusive . RESULTS Available literature pointed to strong evidence for controlled comparative local anesthetic facet joint medial branch blocks in the diagnosis of neck and low back pain . There was moderate evidence in the diagnosis of pain arising from thoracic facet joints . CONCLUSION The evidence obtained from literature review suggests that controlled comparative local anesthetic blocks of facet joint nerves ( medial branch or dorsal ramus ) are reproducible , reasonably accurate , and safe . The sensitivity , specificity , false-positive rates , and predictive values of these diagnostic tests for neck and low back pain have been vali date d and reproduced in multiple studies INTRODUCTION Dry needling ( DN ) is a widely used in treatment of myofascial trigger points ( MTrPs ) . The purpose of this pretest-posttest clinical trial was to investigate the neurophysiological and clinical effects of DN in patients with MTrPs . METHODS A sample of 20 patients ( 3 man , 17 women ; mean age 31.7 ± 10.8 ) with upper trapezius MTrPs received one session of deep DN . The outcomes of neuromuscular junction response ( NMJR ) , sympathetic skin response ( SSR ) , pain intensity ( PI ) and pressure pain threshold ( PPT ) were measured at baseline and immediately after DN . RESULTS There were significant improvements in SSR latency and amplitude , pain , and PPT  after DN . The NMJR decreased and returned to normal after DN . CONCLUSIONS A single session of DN to the active upper trapezius MTrP was effective in improving pain , PPT , NMJR , and SSR in patients with myofascial trigger points . Further studies are needed
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 .