High prevalence of shoulder girdle muscles with myofascial trigger points in patients with shoulder pain Contributions of myofascial pain in diagnosis and treatment of shoulder pain. A randomized control trial Upper cervical mobility, posture and myofascial trigger points in subjects with episodic migraine: Case-control study. Dry Needling to a Key Myofascial Trigger Point May Reduce the Irritability of Satellite MTrPs Dry Needling Alters Trigger Points in the Upper Trapezius Muscle and Reduces Pain in Subjects With Chronic Myofascial Pain. Myofascial Trigger Point-focused Head and Neck Massage for Recurrent Tension-type Headache: A Randomized, Placebo-controlled Clinical Trial Bilateral Activation of Motor Unit Potentials with Unilateral Needle Stimulation of Active Myofascial Trigger Points Myofascial trigger point needling for whiplash associated pain--a feasibility study. Upper trapezius muscle activation patterns in neck–shoulder pain patients and healthy controls Prognostic Factors for Intervention Effect on Neck/Shoulder Symptom Intensity and Disability among Female Computer Workers Shoulder muscle co-ordination during chronic and acute experimental neck-shoulder pain. An occupational pain study Skeletal muscle contractility, self-reported pain and tissue sensitivity in females with neck/shoulder pain and upper Trapezius myofascial trigger points– a randomized intervention study Interrater reliability in myofascial trigger point examination Muscle trigger points and pressure pain hyperalgesia in the shoulder muscles in patients with unilateral shoulder impingement: a blinded, controlled study Active myofascial trigger points might be more frequent in patients with cervical radiculopathy. Risk factors in the onset of neck/shoulder pain in a prospective study of workers in industrial and service companies Dry Needling on the Infraspinatus Latent and Active Myofascial Trigger Points in Older Adults With Nonspecific Shoulder Pain: A Randomized Clinical Trial
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 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 : 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 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 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 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 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 Clinicians cl aim that myofascial trigger points ( MTrPs ) are a primary cause of pain in whiplash injured patients . Pain from MTrPs is often treated by needling , with or without injection . We conducted a placebo controlled study to test the feasibility of a phase III r and omised controlled trial investigating the efficacy of MTrP needling in patients with whiplash associated pain . Forty-one patients referred for physiotherapy with a recent whiplash injury , were recruited . Patients were r and omised to receive st and ardised physiotherapy plus either acupuncture or a sham needle control . A trial was judged feasible if : i ) the majority of eligible patients were willing to participate ; ii ) the majority of patients had MTrPs ; iii ) at least 75 % of patients provided completed self- assessment data ; iv ) no serious adverse events were reported and v ) the end of treatment attrition rate was less than 20 % . 70 % of those patients eligible to participate volunteered to do so ; all participants had clinical ly identified MTrPs ; a 100 % completion rate was achieved for recorded self- assessment data ; no serious adverse events were reported as a result of either intervention ; and the end of treatment attrition rate was 17 % . A phase III study is both feasible and clinical ly relevant . This study is currently being planned This study aim ed at investigating whether patients with neck – shoulder complaints from different aetiologies ( work-related musculo-skeletal disorders , WMSD ; whiplash associated disorders , WAD ) show comparable muscle activation patterns , characterised by higher activation and lower relaxation levels of the trapezius muscles compared to healthy controls . Twenty healthy controls , 21 WMSD and 20 WAD patients with non-acute neck-shoulder pain were recruited for this cross-sectional study .  Surface electromyography ( sEMG ) recordings were performed at the upper trapezius muscles during reference contractions , st and ardised computer tasks ( typing and unilateral stress task ) , and rest measurements . sEMG was continuously recorded during these measurements .  Outcome measures were root mean square ( RMS ) to study muscle activity , and relative rest time ( RRT ) to study muscle relaxation . Statistical analysis comprised the bootstrap technique and Kruskall – Wallis tests . Results showed no clear evidence for abnormal muscle activation patterns in WMSD and WAD patients compared to healthy controls . However , a tendency was observed for higher RMS levels during the reference contractions and computer tasks in both patient groups compared to healthy controls , and lower RRT levels at the non-dominant side during stress . Both patient groups also showed larger variability in RMS and RRT values . This variability has more often been reported in literature and may suggest the existence of subgroups of pain patients with corresponding different muscle activation patterns not related to aetiology . Future research may focus on identifying these subgroups of patients with neck-shoulder pain Introduction It has been suggested that treatments may be more effective when they are matched to patient characteristics . This study aim ed at investigating potential prognostic factors for clinical ly relevant improvement in symptom intensity and symptom-related disability among employees with symptoms in the neck/shoulder area , receiving either ergonomics counseling or such counseling in combination with myofeedback training .  Methods A r and omized controlled study was performed among female computer users aged 45 or older ( n = 36 ) . A clinical examination and a question naire survey were performed before inclusion in the study . Symptom intensity and disability was assessed using question naires before the start of the interventions ( baseline ) and at follow-ups directly after the end of the interventions ( T0 ) and after 3 ( T3 ) and 6 ( T6 ) months . Logistic regression analyses were performed in order to assess prognostic factors for clinical ly relevant improvement in symptom intensity and disability . Results Improvement in symptom intensity was consistently predicted by symptom intensity at baseline . Diagnosis and stress-induced lack of muscular rest were prognostic factors for improvement in symptom intensity at short term follow-up . Baseline disability and passive coping consistently served as prognostic factors for outcome in disability . Few substantial differences were found between the interventions in terms of prognostic factors . Conclusions Myofeedback training in combination with ergonomics counseling seem to be an especially beneficial tool for secondary prevention among employees with moderate levels of symptom intensity and symptom-related disability , who respond to work-related stress by increased/sustained muscle activation , and who tend to employ passive coping to deal with their neck/shoulder symptoms Abstract Little is known about the mechanisms leading to chronic neck-shoulder musculoskeletal disorders  ( MSD ) . The aim of the present study was to investigate and compare motor function during controlled , low load , repetitive work together with chronic or acute experimental neck-shoulder pain . The clinical study was performed on workers with ( n = 12 ) and without ( n = 6 ) chronic neck-shoulder pain . In the experimental study , experimental muscle pain was induced in healthy subjects by intra-muscular injection of hypertonic saline into the trapezius muscle ( n = 10 ) . The assessed parameters related to motor performance were : work task event duration , cutting forces , surface electromyogram ( EMG ) activity in four shoulder muscles , displacement of the centre of pressure , and arm and trunk 3D movements . For controlled cutting force levels , chronic and acute experimental pain provoked a series of changes : a decreased working rhythm and a protective reorganisation of muscle synergy ( experimental study ) , higher EMG frequency contents which may indicate altered motor unit recruitment , and greater postural activity and a tendency towards increased arm and trunk movements . These pain-related changes can play a role in the development of MSD . The present clinical and experimental study demonstrated similar interactions between motor co-ordination and neck-shoulder pain in occupational setting s. We therefore suggest that this experimental model can be used to study mechanisms related to MSD . Information on such modulatory processes may help in the design of new strategies aim ed at reducing the development of MSD Background In relation to Myofascial Triggerpoints ( MFTrPs ) of the upper Trapezius , this study explored muscle contractility characteristics , the occurrence of post-intervention muscle soreness and the effect of dry needling on muscle contractile characteristics and clinical outcomes . Methods Seventy-seven female office workers ( 25 - 46yrs ) with and without neck/shoulder pain were observed with respect to self-reported pain ( NRS-101 ) , pressure-pain threshold ( PPT ) , maximum voluntary contraction ( Fmax ) and rate of force development ( RFD ) at baseline ( pre-intervention ) , immediately post-intervention and 48 hours post-intervention . Symptomatic and asymptomatic participant groups were each r and omized into two treatment sub-groups ( superficial ( SDN ) and deep dry needling ( DDN ) ) after baseline testing . At 48 hours post-intervention participants were asked whether delayed onset muscle soreness ( DOMS ) and /or post-needling soreness had developed . Results Muscle contractile characteristics did not differ between groups at baseline . Forty-six individuals developed muscle soreness ( 39 from mechanical testing and seven from needling ) . No inter-group differences were observed post-intervention for Fmax or RFD for the four sub-groups . Over the observation period , symptomatic participants reported less pain from both SDN ( p= 0.003 ) and DDN ( p=0.011 ) . However , PPT levels were reduced for all participants ( p=0.029 ) . Those reporting DOMS experienced significant decreases in PPT , irrespective of symptom state or intervention ( p=0.001 ) . Conclusions In selected female neck/shoulder pain sufferers , maximum voluntary contraction and rapid force generation of the upper Trapezius was not influenced by clinical ly relevant self-reported pain or the presence of diagnostically relevant MFTrPs . Dry needling , deep or superficial , did not affect measured functional outcomes over the 48-hour observation period . DOMS affected participants uniformly irrespective of pain , MFTrP status or intervention type and therefore is like to act as a modifier . Trial registration Clinical Trials.gov- NCT01710735 Significance and InnovationsThe present investigation is one of the first to examine the hypothesis of gross muscle contractile inhibition due to the presence of diagnostically relevant MFTrPs . Individuals suffering from clinical ly relevant levels of self-reported pain are able to tolerate maximum voluntary contraction testing , but delayed onset muscle soreness ( DOMS ) is a likely side-effect irrespective of symptom status . As a consequence , its confounding effect during subsequent testing must be taken into account 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 Our aim was to describe the differences in the presence of trigger points ( TrPs ) in the shoulder muscles and to investigate the presence of mechanical hypersensitivity in patients with unilateral shoulder impingement and healthy controls . Twelve patients with strictly unilateral shoulder impingement and 10 matched controls were recruited .  TrPs in the levator scapula , supraspinatus , infraspinatus , subscapularis , pectoralis major , and biceps brachii muscles were explored . TrPs were considered active if the local and referred pain reproduced the pain symptoms and the patient recognized the pain as a familiar pain . Pressure pain thresholds ( PPT ) were assessed over the levator scapulae , supraspinatus , infraspinatus , pectoralis major , biceps brachii , and tibialis anterior muscles . Both explorations were r and omly done by an assessor blinded to the subjects ’ condition . Patients with shoulder impingement have a greater number of active ( mean ± SD : 2.5 ± 1 ; P < 0.001 ) and latent ( mean ± SD : 2 ± 1 ; P = 0.003 ) TrPs when compared to controls ( only latent TrPs , mean ± SD : 1 ± 1 ) . Active TrPs in the supraspinatus ( 67 % ) , infraspinatus ( 42 % ) , and subscapularis ( 42 % ) muscles were the most prevalent in the patient group . Patients showed a significant lower PPT in all muscles when compared to controls ( P < 0.001 ) . Within the patient group a significant positive correlation between the number of TrPs and pain intensity ( rs = 0.578 ; P = 0.045 ) was found . Active TrPs in some muscles were associated to greater pain intensity and lower PPTs when compared to those with latent TrPs in the same muscles ( P < 0.05 ) . Significant negative correlations between pain intensity and PPT levels were found . Patients with shoulder impingement showed widespread pressure hypersensitivity and active TrPs in the shoulder muscles , which reproduce their clinical pain symptoms . Our results suggest both peripheral and central sensitisation mechanisms in patients with shoulder impingement syndrome 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 Aims : To quantify the relative contribution of work related physical factors , psychosocial workplace factors , and individual factors and aspects of somatisation to the onset of neck/shoulder pain .  Methods : Four year prospect i ve cohort study of workers from industrial and service companies in Denmark . Participants were 3123 workers , previously enrolled in a cross sectional study , where objective measurement of physical workplace factors was used . Eligible participants were followed on three subsequent occasions with approximately one year intervals . Outcomes of interest were : new onset of neck/shoulder pain ( symptom cases ) ; and neck/shoulder pain with pressure tenderness in the muscles of the neck/shoulder region ( clinical cases ) . Results : During follow up , 636 ( 14.1 % ) participants reported neck/shoulder pain of new onset ; among these , 82 ( 1.7 % ) also had clinical signs of substantial muscle tenderness . High shoulder repetition was related to being a future symptom case , and a future clinical case . Repetition was strongly intercorrelated with other physical measures . High job dem and s were associated with future status as a symptom case , and as a clinical case . A high level of distress predicted subsequent neck/shoulder pain , and neck/shoulder pain with pressure tenderness . Conclusions : High levels of distress , and physical and psychosocial workplace factors are predictors of onset of pain in the neck and /or shoulders , particularly pain with pressure tenderness in the muscles 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
Findings revealed that active and latent MTrPs were prevalent throughout all disorders , however , latent MTrPs did not consistently have a higher prevalence compared to healthy controls .
Conclusions We found limited evidence supporting the high prevalence of active and latent MTrPs in patients with neck or shoulder disorders .
Background Neck and shoulder disorders may be linked to the presence of myofascial trigger points ( MTrPs ) .
These disorders can significantly impact a person ’s activities of daily living and ability to work .
MTrPs can be involved with pain sensitization , contributing to acute or chronic neck and shoulder musculoskeletal disorders .
The aim of this review was to synthesis e evidence on the prevalence of active and latent MTrPs in subjects with neck and shoulder disorders .