Prospective, Randomized, Double-Blind, Placebo-Controlled Clinical Trial Assessing the Effects of Applying a Force to C5 by a Mechanically Assisted Instrument on Referred Pain to the Shoulder.

STUDY DESIGN: Randomized, prospective, double-blind, placebo-controlled clinical trial. OBJECTIVE: To determine the effects of applying a force to C5 of the spine by a mechanically assisted instrument (MAI) in patients with referred shoulder pain. SUMMARY OF BACKGROUND DATA: Manipulating C5 of the spine is a chiropractic treatment for referred shoulder pain; there are no clinical trials evaluating its efficacy. Outcome measures were patient ranked questionnaires and independent examiner findings. One hundred and twenty-five patients were diagnosed with referred shoulder pain of cervical origin; 65 patients were in the treatment cohort and 60 patients in the placebo cohort. METHODS: This was a prospective, randomized, double-blind, placebo-controlled trial assessing the effects of applying a force to C5 by a MAI to patients with referred shoulder pain. The treatment cohort had the MAI set at the maximum setting to transmit a force into the spine; the placebo cohort had the MAI turned off. Primary outcome measures were frequency and severity of extreme shoulder pain obtained via a patient-reported questionnaire; secondary outcome measures were patient ranked pain and functional outcomes as well as examiner assessed range of motion and strength. Assessment procedures were completed at 24 weeks posttreatment and data were analyzed with intent-to-treat protocol. RESULTS: There was a reduction in the frequency but not severity of extreme shoulder pain in the treatment cohort, average ranking reducing from weekly to monthly (P < 0.05). Patients treated with the MAI had 10 N (P = 0.04) better internal rotation strength after 6 months posttreatment. No differences with any other outcome measures between the two cohorts at the 24-week study period. CONCLUSION: The major effect of applying a MAI to the level of C5 of the spine in referred shoulder pain is improved shoulder strength for internal rotation in this randomized double-blinded clinical trial. LEVEL OF EVIDENCE: 2.

A critical overview of the current myofascial pain literature - October 2017.

In this overview of the myofascial pain literature, we have included several original contributions ranging from a study by Bowen and colleagues of trigger points in horses to the introduction of a new clinical entity of "laryngeal muscle myofascial pain syndrome in dysphonic patients." Minerbi and colleagues described for the first time the referred pain patterns of the longus colli muscle, while Casale and associates studied the spinal modulatory action of dry needling or acupuncture stimulation. Many dry needling articles are included in this overview with several recent outcome studies. Slowly, there is increasing scientific support for using dry needling for a variety of conditions. Several researchers explored specific aspects of dry needling, such as needle placements, whether eliciting a local twitch response is desired, and the role of psychological factors in post-needling soreness. Contributions originated in Australia, Belgium, Brazil, Canada, China, Germany, Greece, India, Israel, Italy, Korea, Portugal, Spain, Switzerland, Turkey, the UK, and the USA.

Adolescent idiopathic scoliosis: The Tethered Spine III: Is fascial spiral the key?

This article reports on an observational and treatment case series involving 22 adolescents and preadolescents treated over a 15 year period who had or appeared to be developing idiopathic scoliosis (IS). Common patterns of muscle and fascial asymmetry were observed and treated. Most of these individuals had spinal area pain and the trigger points (TrPs) apparently responsible for this pain were located in muscles at some distance from the spine, yet referred pain to locations throughout the thoracolumbar spine. Asymmetries in tension in these muscles appear to tether the spine in such a way as to contribute to scoliotic curvatures. The most common pattern of asymmetrical muscle tension found in these individuals follows a particular spiral fascial plane and as the fascia in this spiral plane tightened, the scoliotic curvature appeared to increase. Evaluation also showed that 21 of 22 of these individuals have major ligamentous laxity and this may also have contributed to the development of scoliotic curvatures. Furthermore, each of these individuals has marked overpronation of the ankles, with arches that totally collapse when weight-bearing. Based on observation during the care of these 22 subjects, it appears that asymmetry in the degree of pronation may, in some individuals, be a contributing factor in the development of the spiral body organization involved in the development of scoliosis. Common patterns of joint dysfunction were also observed in many of these individuals. There were also some findings of significant muscle weaknesses that appeared to contribute to the development of the spiraling body organization. Treatment of the tethering of the spine from myofascial asymmetries and related joint dysfunction not only resulted in elimination of pain in almost all cases but also, in many cases resulted in significant reduction of scoliotic curvatures including reductions of rib humps. In other cases, it resulted in stabilization of scoliotic curvatures, and in some cases it may have slowed the rate of progression of curvatures. Stretching and strengthening exercises appeared to contribute to the stability of treatment gains. A segment of the treated population had atypical scoliotic curvatures that did not follow the typical spiral pattern. Even in these individuals, there were significant patterns of fascial restriction and joint dysfunction accompanying the curvatures. Prior traumatic injury was a common factor in almost all of these atypical cases. Treatment of myofascial TrPs and asymmetrical fascial tension and accompanying joint dysfunction is proposed as a useful approach to treating pain in adolescents who have or who appear to be developing scoliosis and to treating and controlling and/or decreasing many scoliotic curvatures. This case series is presented as a way to illuminate possible factors in the development of scoliosis and promising treatment strategies to address these factors and to eliminate pain and stabilize or decrease curvatures so that further research can more systematically evaluate the role of these factors. An addendum of two more cases is also included, because of the information that these cases add to the discussion and to treatment approaches. Including the addendum cases, 8 of the subjects had scoliosis as documented by x-rays. The other 16 appeared to be developing scoliosis according to criteria stated below.

Referred Pain Patterns of the Infraspinatus Muscle Elicited by Deep Dry Needling and Manual Palpation.

OBJECTIVES: To identify the most common referred pain (ReP) pattern of the infraspinatus myofascial trigger point (MTrP) and compare its coincidence with the original ReP pattern, to verify whether there are any significant differences by sex and types of technique and to determine the observed signs and symptoms evoked by deep dry needling (DDN) and manual palpation (MPal). DESIGN: A cohort study of patients randomized to two different examination methods (July and August 2016). SETTINGS: Students and staff recruited from Miguel Hernandez University (Southeast Spain). PATIENTS: One hundred thirty-three participants (70.7% women) with shoulder complaints were randomly assigned to either an MPal (n = 67) or DDN group (n = 66). INTERVENTIONS: The same physiotherapist carried out the techniques on all participants, and the same protocol was followed for both the DDN and MPal groups. The physiotherapist did not ask participants about their pain features or other relevant issues. OUTCOME MEASURES: Local twitch response (LTR) and ReP assessed through a visual analogue scale and features of ReP of the infraspinatus muscle. RESULTS: The areas with the highest percentage of ReP were the front (area 3; 27.1%) and back (area 11; 21.1%) of the arm, anterior (area 4; 36.1%) and posterior (area 12; 42.1%) shoulder, and infraspinatus muscle area. DDN proved to be significantly easier than MPal in evoking an LTR (p ≤ 0.001). There were significant differences between sexes in zone 2 (p = 0.041) and no statistically significant differences were found by technique. CONCLUSIONS: The ReP pattern of the infraspinatus muscle coincides with the original pattern described by Travell and Simons, although the neck area should be questioned. The study found no significant differences in the ReP pattern by sex and when comparing MPal with DDN of MTrP of the infraspinatus muscle. DDN proved to be significantly easier than MPal in evoking an LTR.

A critical overview of the current myofascial pain literature - October 2015.

The number of publications about myofascial pain and trigger points (TrP) seems to increase every year. In the current overview we include 27 articles published in past months. The Basic Review section includes articles about the presence and characteristics of TrPs in various neck and shoulder muscles, the correlation between referred pain from active TrPs and knee osteoarthritis, and an anatomical study exploring whether the location of TrPs may be related to the nerve innervation of muscles. Zuil-Escobar and colleagues from Spain considered the intra-rater reliability of the identification of latent TrPs in several leg muscles and the possible correlation of TrP and the presence of a lower medial longitudinal arch. In the section on manual approaches, contributing author Rob Grieve and colleagues continue their studies of TrPs in the lower extremity muscles, while Méndez-Rebolledo and colleagues studied the impact of cross taping and compression. Dry needling (DN) continues to be a topic of interest. We included twelve papers addressing a wide range of topics, such as the effectiveness and safety of DN, and the impact of DN on proprioception, spasticity, and fibromyalgia. Two papers investigated the utilization of repetitive transcranial magnetic stimulation and laser on TrPs, The final section on other clinical studies and reviews includes 8 papers. The studies originated in thirteen different countries with Spain leading the charts with 7 contributions to the literature, followed by Brazil with four. As we have mentioned in previous editions of this literature overview, many studies suffer from very small sample sizes, which makes it difficult to reach definitive conclusions. Nevertheless, myofascial pain continues to be a topic of interest to researchers and clinicians around the globe.

Referred pain patterns of the third and fourth dorsal interosseous muscles.

BACKGROUND: Myofascial pain (MP) is a common disorder that can involve any skeletal muscle in the human body. There are no published reports of the referred pain patterns of the third and fourth dorsal interosseous muscles. OBJECTIVE: To investigate the referred pain patterns of the third and fourth dorsal interosseous muscles. STUDY DESIGN: Prospective evaluation. SETTING: Academic medical center. METHODS: Twenty healthy adults participated in the study. Needle placement and injection of 0.2 mL 6% hypertonic saline solution into the midpoint of the interosseous muscles were performed under ultrasonographic (US) guidance. After the injections, the participants were instructed to wait until they felt the most pain and then draw a pain diagram. This drawing was transferred to the computer for analysis. RESULTS: The referred pain distributions for the third dorsal interosseous muscle were as follows: the interdigital space of the third and fourth fingers, 80%; the distal phalanx of the third and fourth fingers, 45%; and the ulnar side of the palm, 55%. Three and 6 participants reported pain on the volar side of the wrist and in the fifth finger, respectively. The referred pain distributions for the fourth dorsal interosseous muscle were as follows: the interdigital space of the fourth and fifth fingers, 80%; the hypothenar area, 65%; and the distal phalanx of the fourth and fifth fingers, 60%. Seven and 3 participants also reported pain on the ulnar side of the wrist and the ulnar side of the forearm, respectively. LIMITATION: This study is limited by its small sample size. CONCLUSION: Referred pain patterns of the third and fourth interosseous muscles resemble the pain experienced in C7 or C8 radiculopathies or the ulnar neuropathy. Thus, identification of the third and fourth interosseous muscle trigger point should be considered when patients experience pain on the ulnar aspect of the hand and wrist.

Intensive vasodilatation in the sciatic pain area after dry needling.

BACKGROUND: Short-term vasodilatation in the pain area after dry needling (DN) of active trigger points (TrPs) was recorded in several cases of sciatica. Moreover, the presence of TrPs in sciatica patients secondary to primary lesion was suggested. Still, it is not known how often they occur and if every TrPs can provoke vasomotor reactions. The purpose of this study was to evaluate the prevalence of active TrPs among subacute sciatica patients and the response to DN under infrared thermovision (IRT) camera control. METHOD: Fifty consecutive Caucasian patients (mean age 41.2 ± 9.1y) with subacute sciatica were diagnosed towards gluteus minimus TrPs co-existence. Based on TrPs confirmation, patients were divided into two groups: TrPs-positive and TrPs-negative, than DN under IRT control was performed. Skin temperature changes and the percentage size of vasomotor reactions in the pain area were evaluated if present. RESULTS: The prevalence of active TrPs was 32.0%. Every TrPs-positive presented vasodilatation dependent on TrPs co-diagnosis (r = 0.72 p < 0.000) and pain recognition during DN (r = 0.4 p < 0.05). The size of vasodilatation in TrPs-positive subjects was: post-DN 12.3 ± 4.0% and post-observation 22.1 ± 6.1% (both p = 0.000) versus TrPs-negative: post-DN 0.4 ± 0.3% and post-observation 0.4 ± 0.2%. A significant temperature increase in the thigh and calf was confirmed for TrPs-positive subjects only (both p < 0.05). Post-DN and post-observation temperatures were as follows: average (thigh:1.2 ± 0.2°C; 1.4 ± 0.2°C, both p < 0.05 and calf: 0.4 ± 0.2°C; 0.4 ± 0.3°C, both p < 0.05) and maximum (thigh 1.4 ± 0.3°C 1.6 ± 0.3°C; both p < 0.05). CONCLUSIONS: The presence of active TrPs within the gluteus minimus muscle among subacute sciatica subjects was confirmed. Every TrPs-positive sciatica patient presented DN related vasodilatation in the area of referred pain. The presence of vasodilatation suggests the involvement of sympathetic nerve activity in myofascial pain pathomechanism. Although the clinical meaning of TrPs in subacute sciatica patients is possible, further studies on a bigger group of patients are still required. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12614001060639. Registered 3 October 2014.

Myofascial origin of shoulder pain: a literature review.

BACKGROUND: Shoulder pain is a common problem imposing a considerable burden on the affected person and society. Since interventions targeting traditional musculoskeletal conditions are usually only moderately effective, myofascial origin can be suggested as an alternative possible source of shoulder pain. OBJECTIVES: To examine current evidence associated with myofascial origin of shoulder pain, with emphasis on diagnosis, prevalence and treatment efficacy. METHODS: PubMed, Google Scholar and PEDro databases were searched from inception until December 2013 for terms relating to myofascial pain in the shoulder area. RESULTS: Two studies showed a high reliability of the following diagnostic characteristics during palpation: presence or absence of the taut band, spot tenderness, jump sign, pain recognition and referred pain sensation. Three prevalence studies showed a significant greater number of active myofascial trigger points (MTrPs) on the painful shoulder side. Reduced muscle strength, accelerated muscle fatigue, inconsistent muscle activation pattern under load and reduced antagonist reciprocal inhibition were found in subjects with latent MTrPs in four observational studies. Six interventional studies demonstrated the effectiveness of dry needling, myofascial manipulation, ischemic compression, laser therapy and multimodal treatment. CONCLUSION: MTrPs in shoulder muscles is a common condition among patients with shoulder complaints and can be reliably diagnosed by palpation. The reviewed interventions seem to be effective in reducing pain, increasing range of motion and improving function of the painful shoulder.

Antinociceptive effect of botulinum toxin type A on experimental abdominal pain.

Visceral pain, especially in the abdominal region, represents one of the most common types of pain. Its chronic form is usually very hard to treat by conventional analgesic agents and adjuvants. We investigated the antinociceptive effect of botulinum toxin type A (BTX-A) in male Wistar rats in two models of visceral pain: peritonitis induced by intraperitoneal injection of 1% acetic acid and colitis induced by intracolonic instillation of 0.1% capsaicin. Pain was measured as the number of abdominal writhes. Additionally, referred mechanical sensitivity in the ventral abdominal area was evaluated by von Frey test and the extent of spinal c-Fos expression was immunohistochemically examined. BTX-A significantly reduced the number of abdominal writhes in both models of visceral pain after intrathecal application in a dose of 2 U/kg. In the experimental colitis model, BTX-A (2 U/kg) reduced both referred mechanical allodynia and c-Fos expression in the dorsal horn of the spinal cord (S2/S3 segments). In contrast to intrathecal administration, BTX-A (2 U/kg) administered into the cisterna magna had no effect on pain suggesting that the primary site of its action is a spinal cord.

Myofascial trigger point pain.

Myofascial trigger point pain is an extremely prevalent cause of persistent pain disorders in all parts of the body, not just the head, neck, and face. Features include deep aching pain in any structure, referred from focally tender points in taut bands of skeletal muscle (the trigger points). Diagnosis depends on accurate palpation with 2-4 kg/cm2 of pressure for 10 to 20 seconds over the suspected trigger point to allow the referred pain pattern to develop. In the head and neck region, cervical muscle trigger points (key trigger points) often incite and perpetuate trigger points (satellite trigger points) and referred pain from masticatory muscles. Management requires identification and control of as many perpetuating factors as possible (posture, body mechanics, psychological stress or depression, poor sleep or nutrition). Trigger point therapies such as spray and stretch or trigger point injections are best used as adjunctive therapy.

Myofascial trigger points in the masticatory muscles in patients with and without chronic mechanical neck pain.

OBJECTIVES: The purpose of this study is to describe differences in the presence of masseter and temporalis muscle trigger points (TrPs) and jaw opening between individuals with mechanical neck pain and healthy controls. METHODS: Twenty patients with mechanical neck pain (60% women) without symptoms in the orofacial region, aged 20 to 37 years old, and 20 matched controls participated. Temporalis and masseter muscles were examined for the presence of TrPs in a blinded design. Trigger points were considered active if the subject recognized the pain as a familiar symptom, whereas the TrPs was considered latent if the pain was not recognized as a symptom. Jaw opening was assessed with a ruler. RESULTS: A greater number (P < .001) of TrPs in the masticatory muscles were found in patients than in controls. None of the patients or healthy controls recognized the referred pain as familiar; thus, latent rather than active TrPs were found. The distribution of TrPs between groups was different for the masseter (left odds ratio [OR], 3.4; right OR, 8.1; P < .001) and temporalis (left OR, 2.8; right OR, 5.7; P < .001) muscles. Patients with neck pain had smaller jaw opening than controls (P < .001). A negative correlation between active jaw opening and the number of TrPs within the masticatory muscles (r(s) = -0.6; P < .001) was found: the greater the number of TrPs, the smaller the jaw opening. CONCLUSIONS: For the subjects in this study, those with mechanical chronic neck pain had more latent TrPs in the masticatory muscles and reduced jaw opening compared to healthy controls. These findings may suggest the spread of sensitization from the cervical segment to the trigeminal brain stem sensory nuclear complex.

Spatial pain propagation over time following painful glutamate activation of latent myofascial trigger points in humans.

UNLABELLED: The aim of this present study was to test the hypothesis that tonic nociceptive stimulation of latent myofascial trigger points (MTPs) may induce a spatially enlarged area of pressure pain hyperalgesia. Painful glutamate (.2 mL, 1M) stimulation of latent MTPs and non-MTPs in the forearm was achieved by an electromyography-guided procedure. Pain intensity (as rated on the visual analog scale [VAS]) and referred pain area following glutamate injections were recorded. Pressure pain threshold (PPT) was measured over 12 points in the forearm muscles and at the mid-point of tibialis anterior muscle before and at .5 hour, 1 hour, and 24 hours after glutamate injections. The results showed that maximal pain intensity, the area under the VAS curve, and referred pain area were significantly higher and larger following glutamate injection into latent MTPs than non-MTPs (all, P < .05). A significantly lower PPT level was detected over time after glutamate injection into latent MTPs at .5 hour (at 4 points), 1 hour (at 7 points), and 24 hours (at 6 points) in the forearm muscles. However, a significantly lower PPT was observed only at 24 hours after glutamate injection into non-MTPs in the forearm muscles (at 4 points, P < .05) when compared to the pre-injection PPT. PPT at the mid-point of the tibialis anterior was significantly decreased at 1 hour only as compared to the pre-injection PPT in both groups (< .05). The results of the present study indicate that nociceptive stimulation of latent MTPs is associated with an early onset of locally enlarged area of mechanical hyperalgesia. PERSPECTIVE: This study shows that MTPs are associated with an early occurrence of a locally enlarged area of pressure hyperalgesia associated with spreading central sensitization. Inactivation of MTPs may prevent spatial pain propagation.

Development of active myofascial trigger points in neck and shoulder musculature is similar after lumpectomy or mastectomy surgery for breast cancer.

Our aim was to describe the differences in the presence of myofascial trigger points (TrPs) in neck and shoulder muscles after 2 surgery approaches for breast cancer: mastectomy or lumpectomy. Thirty-two women (mean age: 50 ± 7 years) who received lumpectomy, 16 women (mean age: 48 ± 10 years) who had received mastectomy after breast cancer, and 16 women (mean age: 49 ± 9 years) with breast cancer who had not received either surgical treatment, participated. Myofascial TrPs in the upper trapezius, sternocleidomastoid, levator scapulae, scalene, infraspinatus and pectoralis major muscles were bilaterally explored by an assessor blinded to the women's condition. TrPs were considered active when palpation reproduced local and referred pain symptoms recognized by the patient as familiar pain symptoms. The number of active TrPs within mastectomy (mean ± SD: 4.6 ± 1) and lumpectomy (mean ± SD: 4.5 ± 1) groups was significantly higher (P < 0.001) as compared to the control group (mean ± SD: 1.1 ± 1.3), but not significantly different between them (P = 0.641). Women who received either lumpectomy or mastectomy showed similar distribution of active TrPs and a higher prevalence of active TrPs as compared to the control group. Active TrPs in the pectoralis major muscle were the most prevalent in both surgery groups The number of active TrPs was weakly correlated with neck (r(s) = 0.385; P = 0.029) and shoulder/axillary (r(s) = 0.397; P = 0.024) pain intensity within the lumpectomy, but not the mastectomy group. This study found active TrPs in neck and shoulder musculature in women who had received lumpectomy or mastectomy. The induced local and referred pain pattern from active TrPs reproduced neck and shoulder/axillary symptoms and pain patterns in women after breast cancer surgery. Few active TrPs were found in a control group of women with breast cancer who had not received any surgical treatment.

Sensory disturbances in complex regional pain syndrome: clinical observations, autonomic interactions, and possible mechanisms.

OBJECTIVE: To review mechanisms that might contribute to sensory disturbances and sympathetically-maintained pain in complex regional pain syndrome (CRPS). BACKGROUND: CRPS is associated with a range of sensory and autonomic abnormalities. In a subpopulation of patients, sympathetic nervous system arousal and intradermal injection of adrenergic agonists intensify pain. RESULTS: Mechanisms responsible for sensory abnormalities in CRPS include sensitization of primary afferent nociceptors and spinothalamic tract neurons, disinhibition of central nociceptive neurons, and reorganization of thalamo-cortical somatosensory maps. Proposed mechanisms of sympathetically-maintained pain include adrenergic excitation of sensitized nociceptors in the CRPS-affected limb, and interaction between processes within the central nervous system that modulate nociception and emotional responses. Central mechanisms could involve adrenergic facilitation of nociceptive transmission in the dorsal horn or thalamus, and/or depletion of bulbo-spinal opioids or tolerance to their effects. CONCLUSIONS: Sympathetic neural activity might contribute to pain and sensory disturbances in CRPS by feeding into nociceptive circuits at the site of injury or elsewhere in the CRPS-affected limb, within the dorsal horn, or via thalamo-cortical projections.

Myofascial referred-pain data provide physiologic evidence of acupuncture meridians.

UNLABELLED: Recently published data suggest substantial anatomic, clinical, and physiologic (referred pain to meridian) overlap of myofascial trigger points and acupuncture points, particularly in the treatment of pain disorders. This qualitative study examines whether myofascial referred-pain data from the Trigger Point Manual can provide independent physiologic evidence of acupuncture meridians. Trigger point regions were subdivided from prior, validated trigger point region-classical acupuncture point correspondence results into subsets according to the 12 acupuncture Organs of their anatomically corresponding acupuncture points (Bladder, Gallbladder, Heart, Kidney, Large Intestine, Liver, Lung, Pericardium, Small Intestine, Spleen, Stomach, and Triple Energizer). The referred-pain patterns for each subset of trigger point regions were graphically applied to a virtual human model along with the subset's corresponding acupuncture Principal meridian. All 12 meridian distributions were compared qualitatively with the summed referred-pain distributions of their anatomically corresponding trigger point regions. For all 12 subsets of trigger point regions, their summed referred-pain patterns accurately predicted the distributions of their corresponding acupuncture meridians, particularly in the extremities. The myofascial referred-pain data from the Trigger Point Manual provides independent physiologic evidence of acupuncture meridians. Understanding these meridians may enhance treatment of both pain and non-pain conditions. PERSPECTIVE: This article demonstrates that myofascial referred-pain data provide independent physiologic evidence of acupuncture meridians. The acupuncture tradition provides pain practitioners with millennia of accumulated clinical experience treating pain (and visceral) disorders and offers the potential for novel pain treatment approaches and understanding of pain neurophysiology.

[Mechanisms of muscle pain : significance of trigger points and tender points]. / Mechanismen des Muskelschmerzes : Bedeutung von Trigger points und Tender points.

Fibromyalgia syndrome (FMS) and myofascial pain syndrome (MPS) belong to the group of chronic non-inflammatory pain syndromes affecting muscles and tendinous insertions. Important criteria in the diagnosis of both diseases are the presence of "tender points" and "trigger points". According to ACR criteria FMS is characterized by the presence of tender points whereas trigger points are typically found in MPS.The main difference is that until now tender points could only be defined in terms of their localization, whereas trigger points can be found upon palpation which may cause a specific referred pain pattern. In addition, analysis of trigger points by microdialysis demonstrated elevated levels of pro-inflammatory substances at these sites. Moreover, local treatment of trigger points either by manipulative therapy or injection appears to be most effective for prompt relief of symptoms.

Multimodal sensory testing of the rectum and rectosigmoid: development and reproducibility of a new method.

Evaluation of rectal and rectosigmoid sensation is important in basic, clinical and pharmacological studies. New methods to evoke and assess multimodal (electrical, thermal and mechanical) experimental pain of the upper gut activate distinct pathways and mimics clinical pain. The aims of the current study were to characterize the sensory response and reproducibility to multimodal stimulation of rectum and the rectosigmoid. A multimodal rectal probe was developed. Mucosal electrostimulation was delivered at the recto-sigmoid junction. In Rectum, impedance planimetry was used for measurement of cross-sectional area (CSA) during distension. Circulation of water within the bag at either 4 or 60 degrees C was applied for thermal stimulation. The method was tested in 12 healthy volunteers (six men mean age 32 years) on two subsequent days. Mechanical and sensory responses and referred pain areas were assessed. Stimulation with electrical, thermal and mechanical modalities resulted in different sensory perceptions. The relationship between stimulus intensity and sensory response was linear for all modalities. Sensory response to different modalities did not differ between investigation days (all P-values > 0.1). Approximately 75% of subjects felt referred pain in distinct skin locations. Between-days reproducibility was good for all modalities [intra-class correlation (ICC) > or = 0.6]. At sensory threshold, CSA showed best reproducibility (ICC > or = 0.9). At pain detection threshold stretch ratio, CSA and electrostimulation showed best reproducibility (ICC = 1.0; 0.9; 0.9). The present model was easily implemented, robust and showed good reproducibility. It can be used to study pathophysiology or pharmacological interventions in healthy controls and in patients with diseases involving the distal hindgut.

Induction of muscle cramps by nociceptive stimulation of latent myofascial trigger points.

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.

Acupuncture at GV01 relieves somatic pain referred by colitis in rats.

The present study aimed to expand our previous findings regarding the therapeutic effects and underlying mechanisms of acupuncture at GV01 in colitis. Our results showed that acupuncture at GV01 has antinociceptive effects on referred somatic pain induced by experimental colitis, and that endogenous opioid pathways may mediate these effects.

The efficacy of acupuncture in the treatment of temporomandibular joint myofascial pain: a randomised controlled trial.

OBJECTIVES: To compare the effect of real acupuncture and sham acupuncture in the treatment of temporomandibulat joint myofascial pain, in order to establish the true efficacy of acupuncture. METHODS: A double blind randomised controlled trial conducted in the TMD Clinic, at the School of Dentistry, The University of Manchester. Twenty-seven patients were assigned to one of two treatment groups. Group 1 received real acupuncture treatment whilst Group 2 received a sham acupuncture intervention. Both the assessor and the patient were blinded regarding the group allocation. Baseline assessment of the outcome variables was made prior to the first treatment session, and was repeated following the last treatment. RESULTS: The results demonstrated that real acupuncture had a greater influence on clinical outcome measure of TMJ MP than those of sham acupuncture, and the majority of these reached a level of statistical significance. CONCLUSION: Acupuncture had a positive influence on the signs and symptoms of TMJ MP. In addition, this study provides evidence that the Park Sham Device was a credible acupuncture control method for trials involving facial acupoints.