A proposed experimental model of myofascial trigger points in human muscle after slow eccentric exercise

Deep electroacupuncture of neurogenic spots attenuates immobilization stress-induced acute hypertension in rats

Background

Our previous studies proved that neurogenic inflammatory spots (or neurogenic spots) have the same physiological features as acupuncture points and that neurogenic spot stimulation generates therapeutic effects in various animal models. However, it is unclear how deeply the neurogenic spots should be stimulated to generate therapeutic effects.

Methods

The effects of acupuncture at various needle depths below the neurogenic spot were examined in a rat immobilization stress-induced hypertension (IMH) model. Electroacupuncture was applied to a neurogenic spot at depths of 1, 2, or 3 mm using a concentric bipolar electrode.

Results

Electrical stimulation of the neurogenic spot at a 3-mm depth most effectively lowered blood pressure compared with controls and stimulation at 1- and 2-mm depths, which was inhibited by pretreatment with a local anesthetic lidocaine. Electrical stimulation of the neurogenic spot or injection of substance P (SP) at a 3-mm depth significantly excited the rostral ventrolateral medulla (rVLM) compared with superficial stimulation. Electrical stimulation applied at a 3-mm depth on neurogenic spots dominantly caused c-fos expression from rVLM and ventrolateral periaqueductal gray (vlPAG) in IMH rats. Pretreatment with resiniferatoxin (RTX) injection into the neurogenic spot to ablate SP or calcitonin gene-related peptide (CGRP) prevented the effects of 3-mm neurogenic spot stimulation on blood pressure in IMH rats. Conversely, artificial injection of SP or CGRP generated anti-hypertensive effects in IMH rats.

Conclusion

Our data suggest that neurogenic spot stimulation at a 3-mm depth generated anti-hypertensive effects through the local release of SP and CGRP and activation of rVLM and vlPAG.

Neurochemical mechanism of muscular pain: Insight from the study on delayed onset muscle soreness

We reviewed fundamental studies on muscular pain, encompassing the characteristics of primary afferent fibers and neurons, spinal and thalamic projections, several muscular pain models, and possible neurochemical mechanisms of muscle pain. Most parts of this review were based on data obtained from animal experiments, and some researches on humans were also introduced. We focused on delayed-onset muscle soreness (DOMS) induced by lengthening contractions (LC), suitable for studying myofascial pain syndromes. The muscular mechanical withdrawal threshold (MMWT) decreased 1-3 days after LC in rats. Changing the speed and range of stretching showed that muscle injury seldom occurred, except in extreme conditions, and that DOMS occurred in parameters without muscle damage. The B2 bradykinin receptor-nerve growth factor (NGF) route and COX-2-glial cell line-derived neurotrophic factor (GDNF) route were involved in the development of DOMS. The interactions between these routes occurred at two levels. A repeated-bout effect was observed in MMWT and NGF upregulation, and this study showed that adaptation possibly occurred before B2 bradykinin receptor activation. We have also briefly discussed the prevention and treatment of DOMS.

Pressure pain threshold map of thoracolumbar paraspinal muscles after lengthening contractions in young male asymptomatic volunteers

This study aimed to characterise topographic distribution of pressure pain thresholds (PPTs) of thoracolumbar paraspinal muscles and its change after lengthening contractions (LCs) of the back muscles. Using young male asymptomatic participants in Experiment 1, we systematically examined the distribution of PPTs bilaterally in the range of Th1–L5 at measurement points 2 and 4 cm from the midline. PPTs were found to be higher in the lumbar segments of the paraspinal muscles than in the thoracic segments, and in muscles closer to the vertebrae (2 vs. 4 cm from the midline). The PPTs did not differ between the left and right sides in each segment. In Experiment 2, LC was applied by asking a part of participants recruited in Experiment 1 to fall their trunk from a starting position (parallel to the floor) to 40° flexed position, and then made it back as quickly as possible to the starting position. This cycle was repeated until participants could not keep contractions (30 times/set, 25.4 ± 10.6 sets). PPTs of the LC group decreased prominently in the lower thoracic and lumbar segments, and the decrease was more evident 24 h after LC compared to that 48 h after. In contrast, PPTs in the control group without LC remained unchanged. These results provided broad topographic images of PPTs in the thoracolumbar paraspinal muscles of young male participants with and without LC, and the obtained PPT maps could be a useful guide for better treatment of exercise-induced myofascial pain in the lower back.

Pressing Intervention Promotes the Skeletal Muscle Repair of Traumatic Myofascial Trigger Points in Rats

Objective

To observe the effect of pressing intervention on the skeletal muscle repair of myofascial trigger points (MTrPs) in rats and explore the mechanism of pressing intervention on the deactivation of trigger points.

Methods

Thirty SPF rats were randomly divided into blank group, model group and press group, with 10 rats in each group. The MTrPs models were established by blunt striking plus eccentric exercise, and then evaluated. The press group was given a pressing intervention with a self-made device for 14 days, and the rats in the other two groups were fed normally. Soft tissue tension (STT) D_0.2 and pressure pain threshold (PPT) were measured before and after intervention. The skeletal muscle tissue at MTrPs was extracted and assessed by hematoxylin–eosin (HE) and Masson staining. The expression of collagen I, collagen III, α- smooth muscle actin (α-SMA), myosin heavy chain (MHC) and fibronectin (FN) were detected by Western Blotting. Enzyme linked immunosorbent assay (ELISA) was used to evaluate the expression of substance P (SP), 5-hydroxytryptamine (5-HT), cyclooxygenase 2 (COX-2) and prostaglandin E2 (PGE2).

Results

(1) Compared with the blank group, the PPT and D_0.2 reduced (P < 0.05) in the model group; while compared with the model group, the PPT and D_0.2 increased (P < 0.05) in the press group. (2) Compared with the blank group, the model group showed obvious spontaneous potentials with higher amplitude and frequency, which were also much higher than those of the press group (P < 0.05). (3) The HE and Masson staining results showed evident fibrosis in the muscle tissue of the model group, with a larger area of collagen fibers relative to that of the press group (P < 0.05). (4) The amount of collagen I, collagen III, FN, α- SMA, SP, 5-HT, COX-2 and PGE2 increased and the content of MHC decreased (P < 0.05) in the model group, as compared to the blank group; while all the substances (P < 0.05), instead of MHC which increased (P < 0.05), in the press group were decreased as compared to the model group.

Conclusion

Pressing intervention on the MTrPs in rats can alleviate chronic inflammation, inhibit fibrosis, promote skeletal muscle repair and relieve pain.

The effect of vibration therapy on neck myofascial trigger points: A randomized controlled pilot study

BACKGROUND

The purpose of this study was to evaluate the effect of low-frequency self-administered vibration therapy into myofascial trigger points in the upper trapezius and levator scapulae on patients with chronic non-specific neck pain.

METHODS

Twenty-eight patients with chronic non-specific neck pain were randomly assigned into a vibration group, receiving 10 self-applied sessions of vibration therapy in the upper trapezius and levator scapulae trigger points; or a control group, receiving no intervention. Self-reported neck pain and disability (Neck Disability Index) and pressure pain threshold were assessed at baseline and after the first, fifth and 10th treatment sessions.

FINDINGS

Significant differences were found in the vibration group when compared to the control group after the treatment period: the vibration group reached lower Neck Disability Index scores (F = 4.74, P = .033, η² = 0.07) and greater pressure pain threshold values (F = 7.56, P = .01, η² = 0.10) than the control group. The vibration group reported a significant reduction in Neck Disability Index scores (χ2 = 19,35, P = .00, Kendall's W = 0.28) and an increase in pressure pain threshold (χ2 = 87,10, P = .00, Kendall's W = 0.73) between the assessment times over the course of the treatment. The mean increase in pressure pain threshold in the vibration group after the 10 sessions was 8.54 N/cm2, while the mean reduction in Neck Disability Index scores was 4.53 points.

INTERPRETATION

Vibration therapy may be an effective intervention for reducing self-reported neck pain and disability and pressure pain sensitivity in patients with chronic non-specific neck pain. This tool could be recommended for people with non-specific neck pain.

Depression of Mitochondrial Function in the Rat Skeletal Muscle Model of Myofascial Pain Syndrome Is Through Down-Regulation of the AMPK-PGC-1α-SIRT3 Axis

Purpose

The causative mechanisms triggering myofascial pain syndrome (MPS) are still in debate. It is becoming evident that mitochondrial dysfunction may regulate pathways controlling MPS. The aim of this study was to investigate whether AMPK-PGC-1α-SIRT3 axis is associated with depression of mitochondrial function in the rat MPS model.

Methods

A total of 32 Sprague-Dawley rats were randomly divided into control group and experimental group. The expression level of mRNA and protein of gastrocnemius medialis (GM) was analyzed by Western blot and RT-PCR. The histopathological findings were investigated through electron microscopes in GM of all groups.

Results

Our results showed that MPS induces continuous depression of mitochondrial biogenesis and function via down-regulation of PGC-1α-SIRT3 axis accompanying with ATP fuel crisis as compared to control group. However, the expression level of SIRT3 mRNA did not change. Additionally, a correlated reduction of the mRNA and protein expression level of NRF-1 and TFAM, known as the downstream target of PGC-1α, suggesting further transcription of nuclear genes encoding mitochondria functional proteins for promoting mitochondria proliferation, oxidative phosphorylation and energy production is continuously depressed. Furthermore, phosphorylation extent of AMPK is also declined following MPS, and it is negatively correlated with reduction of ATP generation, suggesting that the complex network involves different inhibition in transcription, post-translational modification and a plethora of other effectors that mediate the inhibition roles.

Conclusion

We here suggested that the down-regulation in AMPK-PGC-1α-SIRT3 axis network may be the basis for the association between mitochondrial dysfunction and MPS, where a vicious circle further aggravates the disease symptoms with ongoing ATP energy crisis.

Improving characterization and diagnosis quality of myofascial pain syndrome: a systematic review of the clinical and biomarker overlap with delayed onset muscle soreness

INTRODUCTION

Myofascial pain syndrome (MPS) is one of the most common conditions of chronic musculoskeletal pain, yet its mechanisms are still poorly understood. Delayed Onset Muscle Soreness (DOMS) is also a regional pain syndrome that has clinical similarities to MPS, but has been better investigated. Emerging research suggests that DOMS may be a valid experimental model for studying MPS; however, a comparison of the similarities and differences of these two conditions has previously not been performed. Herein, we aimed to identify the similarities and differences in the clinical features and biomarkers between DOMS and MPS in order to better define MPS and identify future areas of (DOMS-informed) MPS research.

EVIDENCE ACQUISITION

In order to identify similarities and differences in the clinical manifestation and biomarkers of DOMS and MPS, scoping literature searches were performed using Medline (1965-2019), Embase (1966-2019) and Central (1966-2019) databases. Fifty-three full-text articles were reviewed out of the 2836 articles retrieved in the search.

EVIDENCE SYNTHESIS

A scoping review of the literature demonstrated that DOMS and MPS similarly present as conditions of musculoskeletal pain that are associated with decreased strength and limited range of motion. However, while taut bands and discrete tender spots were described in DOMS, none of the studies reviewed have characterized whether these tender points represent the classic myofascial trigger point phenomenon observed in MPS. Certain systemic circulation biomarkers, including inflammatory cytokines and growth factors, were commonly elevated in MPS and DOMS; further research is needed to determine if other biomarkers that are currently characterized in DOMS are useful to enhance the clinical evaluation of MPS.

CONCLUSIONS

DOMS and MPS share clinical and biomarker similarities suggesting that DOMS may be a useful model for studying MPS.

Nonsteroidal anti-inflammatory drugs and acetaminophen ameliorate muscular mechanical hyperalgesia developed after lengthening contractions via cyclooxygenase-2 independent mechanisms in rats

Nonsteroidal anti-inflammatory drugs and acetaminophen are cyclooxygenase inhibitors commonly used as symptomatic medicines for myofascial pain syndrome. Using the selective inhibitors celecoxib and zaltoprofen, cyclooxygenase-2 has been shown to be involved in the initiation, but not the maintenance, of muscular mechanical hyperalgesia induced by lengthening contractions, which serves as a useful model for the study of myofascial pain syndrome. The effect of other cyclooxygenase-2 inhibitors, such as acetylsalicylic acid, ibuprofen, loxoprofen sodium, and acetaminophen, on muscular mechanical hyperalgesia during maintenance has not been studied. Here, we examined the analgesic effects of the nonsteroidal anti-inflammatory drugs and acetaminophen on the model. Consistent with previous studies, mechanical withdrawal threshold of the muscle was significantly decreased and reached its lowest level 24 h after lengthening contractions. Celecoxib had no effect on muscular mechanical hyperalgesia, when orally administered 24 h after lengthening contractions. In contrast, acetylsalicylic acid, ibuprofen, loxoprofen sodium, and acetaminophen increased the withdrawal threshold, which had decreased by lengthening contractions, in a dose-dependent manner. These results demonstrate the analgesic actions of nonsteroidal anti-inflammatory drugs and acetaminophen in the maintenance process of lengthening contraction-induced muscular mechanical hyperalgesia, which may occur through cyclooxygenase-2 independent mechanisms.

The Use of Acupuncture in the Treatment of Temporomandibular Dysfunction – An Audit

Objective

Temporomandibular dysfunction often represents a major therapeutic problem in a dental practice. Evidence from clinical studies suggests that acupuncture may be useful in the treatment of temporomandibular dysfunction. However, most studies have been performed in university settings. The aims of this study were to determine if the results of acupuncture treatment of temporomandibular dysfunction in general dental practice are comparable to the results obtained in previous studies in university clinics, and whether the treatment approach differs from that used in previous studies.

Methods

The case reports submitted by 15 dentists applying for the diploma of the British Dental Acupuncture Society were combined into one audit. All dentists were informed before submitting the forms that the data might be used for scientific purposes. The criteria for Pain Syndrome Dysfunction were used as inclusion criteria. A visual analogue scale (VAS) was used to assess the pain intensity before and after acupuncture treatment. The acupuncture points and technique used were recorded for each treatment.

Results

A total number of 70 case reports were received. Ten patients were excluded, as they did not fulfil the criteria. The remaining 60 patients (50 female) fulfilled an average of 3.2 of the Pain Syndrome Dysfunction criteria, out of a possible five. Their mean age was 40.6 years (range 14–68). The average duration of temporomandibular dysfunction was 32 months (range 1–180). The patients received a mean of 3.4 treatments, each treatment lasting on average 12 minutes. The dentists used only manual stimulation, and mainly acupuncture points over the temporomandibular joint and in the masticatory muscles, points on the neck, and additional relaxing points. The mean pain scores were 7.35 (SD 1.52) before treatment and 2.67 (SD 0.58) after treatment (P<0.001). A beneficial effect was observed in 85% with an average reduction in the pain intensity of 75%.

Conclusion

This audit shows that the results of using acupuncture in the treatment of temporomandibular dysfunction in a general dental practice are comparable to those obtained in clinical studies in university settings. Also the therapeutic approach of using acupuncture is similar. Thus, acupuncture is a simple, relatively safe and potentially efficacious and useful technique in the management of temporomandibular dysfunction in a general dental practice.

Mechanisms of Action of Acupuncture for Chronic Pain Relief – Polymodal Receptors Are the Key Candidates

Therapeutic benefits of acupuncture for chronic pain patients have been clearly identified in recent clinical trials. Underlying mechanisms of acupuncture action mediated by endogenous opioids have been well demonstrated. The existence of pain inhibitory systems in the central nervous system has also been clarified and acupuncture seems to be a potent stimulus for activating the analgesic systems, although the pain mechanisms in acute and chronic states are essentially different. On the other hand, the exact nature of the acupuncture point still remains unclear. Here, we propose a key role of polymodal receptors (PMR) in acupuncture and moxibustion and offer a rational explanation of the acupuncture point as a sensitised PMR.

Moxibustion (burning of moxa) therapy has been shown by medical historians to predate the use of acupuncture, and the meridian theory developed in association with moxibustion treatment. A variety of sensory receptors are activated by acupuncture and/or moxibustion, but there are very few that can be excited by both stimuli. PMRs are one of the most promising candidates. The functional characteristics of PMRs correspond with those of acupuncture action in the periphery; and tender or trigger points, one of the primitive features of acupuncture points, are assumed to be the sites of sensitised PMRs. Diffuse noxious inhibitory control (DNIC) is proposed as a possible mechanism of immediate action of acupuncture, and inputs for the development of DNIC seem to be the PMRs.

In our experimental model, repeated eccentric contractions of muscle produced local tenderness at the palpable band and induced a typical referred pain pattern on application of pressure. Repeated indomethacin injections inhibited the production of the experimental trigger point.

These lines of evidence suggest that the acupuncture points are the sites where the PMRs are sensitised and that such conditions might be repeatedly produced by various biomechanical stressors, insufficient blood supply and metabolic products.

Trigger Point Acupuncture for Treatment of Knee Osteoarthritis – a Preliminary Rct for a Pragmatic Trial

Background

There is evidence for the efficacy of acupuncture treatment in knee osteoarthritis, but it remains unclear which acupuncture modes are most effective. We evaluated the effects of trigger point acupuncture on pain and quality of life in knee osteoarthritis patients, compared with acupuncture at standard points, and sham acupuncture.

Methods

Thirty patients (27 women, 3 men; aged 61–82 years) with non-radiating knee osteoarthritis pain for at least six months and normal neurological examination were randomised to one of three groups for the study period of 21 weeks. Each group received five acupuncture treatment sessions. The standard acupuncture point group ( n=10) received treatment at traditional acupuncture points for knee pain; the trigger point acupuncture group ( n=10) received treatment at trigger points; and the third group ( n=10) received sham acupuncture treatment at the trigger points. Outcome measures were pain intensity (visual analogue scale, VAS) and WOMAC index (Western Ontario and McMaster Universities Arthritis Index). The groups were compared by the area under the curve method.

Results

Five patients dropped out of the study because of lack of improvement, and one patient (in the trigger point acupuncture group) dropped out because of deterioration of symptoms; the remaining 24 patients were included in the analysis. After treatment, the trigger point acupuncture group reported less pain intensity on VAS than the standard acupuncture or sham treatment group, but both the trigger point acupuncture and standard acupuncture groups reported improvement of function of knee. There was a significant reduction in pain intensity between pre-treatment and five weeks after treatment for the trigger point acupuncture (P<0.01) and standard acupuncture groups (P<0.01) included in the analysis, but not for the sham treatment group. Group comparison using the area under the curves demonstrated a significant difference only between trigger point acupuncture and sham treatment groups analysed (P<0.025 for VAS, and P<0.031 for WOMAC).

Conclusion

These results suggest that trigger point acupuncture therapy may be more effective for osteoarthritis of the knee in some elderly patients than standard acupuncture therapy.

Combination of Exercise and Acupuncture Versus Acupuncture Alone for Treatment of Myofascial Pain Syndrome: A Randomized Clinical Trial

Myofascial pain syndrome (MPS) is a common musculoskeletal disorder. This study was designed to compare the effects of aerobic exercise plus acupuncture with acupuncture alone in treatment of patients with MPS. Sixty-four patients (55 female and 9 male) with MPS in their neck and shoulders participated in the study with mean age of 33.1 ± 6.4 years. Participants were randomly allocated to aerobic exercise plus acupuncture (n = 32) or acupuncture alone (n = 32) groups. Outcome measurements included visual analog scale, pressure pain threshold, neck disability index, and quality of life that was measured with QoL-SF36 scale. Each group received 10 sessions of acupuncture in combination with aerobic exercise or acupuncture alone. The outcome measures were evaluated at baseline, at the end of the last treatment session, and at 1-month follow-up visit. While participants were waiting for their 1-month follow-up visit, the patients who received combination therapy were asked to continue their aerobic exercise by jogging 40 minutes a day. Although mean visual analog scale, pressure pain threshold, neck disability index, and QoL-SF36 were significantly improved in both groups (p < 0.001), there was no statistically significant difference among the measures between the two groups throughout the evaluated sessions. The interaction effect of time and groups did not show any significant difference among the outcome measures (p > 0.29).

Histopathological nature of myofascial trigger points at different stages of recovery from injury in a rat model

Objective

To investigate the histopathological nature of myofascial trigger points (MTrPs) or spots (MTrSs) at different stages of recovery from injury in a rat model.

Methods

Forty Sprague–Dawley rats were randomly divided into two groups: a control group (CG) and experimental group (EG). The CG was further randomly subdivided into CG1 and CG2 subgroups. The CG2 was used for palpating the taut band and CG1 as a blank. EG was subdivided into three groups according to recovery times: 4 weeks (4W), 8 weeks (8W) and 12 weeks (12W); these groups consisted of eight rats each. All CG rats received no intervention, whereas the intervention in EG rats was by a blunt strike to the vastus medialis and eccentric exercise for 8 weeks. The taut bands with spontaneous electrical activity were then detected in the muscle to guide a muscle biopsy. The histopathological findings were investigated under optical and electron microscopes in all groups.

Results

Under optical microscopy, the differently augmented sizes of round fibres (contracture knots) with deep staining in the transverse section and fusiform shapes in a longitudinal view were clearly seen in CG2 and EGs with a large diameter; the number of contracture knots was significantly more in EGs than in CGs. Under an electron microscope, the mitochondria in EGs significantly decreased with abnormal structures. The sarcomeres were significantly shortened in the 8W and 12W EGs.

Conclusion

An injury can cause activation of MTrSs in a muscle and an activated level of MTrPs depending on the number of contracture knots in muscle with impaired energy production.

Studying Hardness Meter Spring Strength to Understand Hardness Distribution on Body Surfaces

INTRODUCTION

For developing a hardness multipoint measurement system for understanding hardness distribution on biological body surfaces, we investigated the spring strength of the contact portion main axis of a biological tissue hardness meter (product name: PEK).

METHODS

We measured the hardness of three-layered sheets of six types of gel sheets (90 mm × 60 mm × 6 mm) constituting the acupuncture practice pads, with PEK measurements of 1.96 N, 2.94 N, 3.92 N, 4.90 N, 5.88 N, 6.86 N, 7.84 N, 8.82 N, and 9.81 N of the main axis spring strength. We obtained measurements 10 times for the gel sheets and simultaneously measured the load using a digital scale. We measured the hardness distribution of induration embedded and breast cancer palpation models, with a main axis with 1.96 N, 4.90 N, and 9.81 N spring strengths, to create a two-dimensional Contour Fill Chart.

RESULTS

Using 4.90 N spring strength, we could obtain measurement loads of ≤3.0 N, and the mean hardness was 5.14 mm. This was close to the median of the total measurement range 0.0-10.0 mm, making the measurement range the largest for this spring strength. We could image the induration of the induration-embedded model regardless of the spring strength.

CONCLUSION

Overall, 4.90 N spring strength was best suited for imaging cancer in the breast cancer palpation model.

The local twitch response during trigger point dry needling: Is it necessary for successful outcomes?

BACKGROUND

Myofascial trigger point (MTrP) injection and trigger point dry needling (TrPDN) are widely accepted therapies for myofascial pain syndrome (MPS). Empirical evidence suggests eliciting a local twitch response (LTR) during needling is essential.

OBJECTIVE

This is the first review exploring the available literature, regardless of study design, on the neurophysiological effects and clinical significance of the LTR as it relates to reductions in pain and disability secondary to MTrP needling.

METHODS

PubMed, MEDLINE, Science Direct and Google Scholar were searched up until October 2016 using terms related to trigger point needling and the LTR.

RESULTS

and Discussion: Several studies show that eliciting a LTR does not correlate with changes in pain and disability, and multiple systematic reviews have failed to conclude whether the LTR is relevant to the outcome of TrPDN. Post needling soreness is consistently reported in studies using repeated in and out needling to elicit LTRs and increases in proportion to the number of needle insertions. In contrast, needle winding without LTRs to MTrPs and connective tissue is well supported in the literature, as it is linked to anti-nociception and factors related to tissue repair and remodeling. Additionally, the positive biochemical changes in the MTrP after needling may simply be a wash out effect related to local vasodilation. While the LTR during TrPDN appears unnecessary for managing myofascial pain and unrelated to many of the positive effects of TrPDN, further investigation is required.

Delayed onset muscle soreness: Involvement of neurotrophic factors

Delayed-onset muscle soreness (DOMS) is quite a common consequence of unaccustomed strenuous exercise, especially exercise containing eccentric contraction (lengthening contraction, LC). Its typical sign is mechanical hyperalgesia (tenderness and movement related pain). Its cause has been commonly believed to be micro-damage of the muscle and subsequent inflammation. Here we present a brief historical overview of the damage-inflammation theory followed by a discussion of our new findings. Different from previous observations, we have observed mechanical hyperalgesia in rats 1-3 days after LC without any apparent microscopic damage of the muscle or signs of inflammation. With our model we have found that two pathways are involved in inducing mechanical hyperalgesia after LC: activation of the B2 bradykinin receptor-nerve growth factor (NGF) pathway and activation of the COX-2-glial cell line-derived neurotrophic factor (GDNF) pathway. These neurotrophic factors were produced by muscle fibers and/or satellite cells. This means that muscle fiber damage is not essential, although it is sufficient, for induction of DOMS, instead, NGF and GDNF produced by muscle fibers/satellite cells play crucial roles in DOMS.

Multi-Acupuncture Point Injections and Their Anatomical Study in Relation to Neck and Shoulder Pain Syndrome (So-Called Katakori) in Japan

Katakori is a symptom name that is unique to Japan, and refers to myofascial pain syndrome-like clinical signs in the shoulder girdle. Various methods of pain relief for katakori have been reported, but in the present study, we examined the clinical effects of multi-acupuncture point injections (MAPI) in the acupuncture points with which we empirically achieved an effect, as well as the anatomical sites affected by liquid medicine. The subjects were idiopathic katakori patients (n = 9), and three cadavers for anatomical investigation. BL-10, GB-21, LI-16, SI-14, and BL-38 as the WHO notation were selected as the acupuncture point. Injections of 1 mL of 1% w/v mepivacaine were introduced at the same time into each of these points in the patients. Assessment items were the Pain Relief Score and the therapeutic effect period. Dissections were centered at the puncture sites of cadavers. India ink was similarly injected into each point, and each site that was darkly-stained with India ink was evaluated. Katakori pain in the present study was significantly reduced by MAPI. Regardless of the presence or absence of trigger points, pain was significantly reduced in these cases. Dark staining with India ink at each of the points in the anatomical analysis was as follows: BL-10: over the rectus capitis posterior minor muscle and rectus capitis posterior major muscle fascia; GB-21: over the supraspinatus muscle fascia; LI-16: over the supraspinatus muscle fascia; SI-14: over the rhomboid muscle fascia; and BL-38: over the rhomboid muscle fascia. The anatomical study suggested that the drug effect was exerted on the muscles above and below the muscle fascia, as well as the peripheral nerves because the points of action in acupuncture were darkly-stained in the spaces between the muscle and the muscle fascia.

Spontaneous electrical activities at myofascial trigger points at different stages of recovery from injury in a rat model

Background

Spontaneous electrical activity (SEA) is a feature of myofascial trigger points (MTrPs), which can either be latent or active. However, SEA at different stages of recovery from MTrPs remains unclear.

Objective

To investigate the temporal changes in the nature of SEA after generation of MTrPs in a rat model.

Methods

32 rats were divided into four groups: 24 rats were assigned to experimental groups (EGs), which underwent the MTrP modelling intervention and 8 were allocated to a control group (CG). All EG rats received a blunt strike to the left vastus medialis combined with eccentric exercise for 8 weeks. After modelling, the EG rats were subdivided into three groups with total recovery times of 4, 8 and 12 weeks (EG-4w, EG-8w and EG-12w, respectively). Taut bands (TBs) with and without the presence of active MTrPs were identified in the left hind limb muscles of all rats, verified by SEA and further examined with electromyography recordings. Myoelectrical signals were also categorised into one of five types.

Results

CG rats had fewer TBs than EG rats and EGs showed variable frequencies of SEA. SEA frequencies were higher in EG-4w than in EG-8w and EG-12w groups (240.57±72.9 vs 168.14±64.5 and 151.63±65.4, respectively, p<0.05) and were significantly greater in all EGs than in the CG (55.75±21.9). Relative to CG rats, amplitudes and durations of electrical potentials in the EG were only increased in the EG-8w and EG-12w groups. Types IV and V myoelectrical signals were never seen in latent MTrPs and type V signals did not occur in EG-4w rats.

Conclusions

Increasing recovery periods following a MTrP modelling intervention in rats are characterised by different frequencies and amplitudes of SEA from TBs.

Trial registration number

2014012.

An MRI-based leg model used to simulate biomechanical phenomena during cuff algometry: a finite element study

Cuff pressure stimulation is applicable for assessing deep-tissue pain sensitivity by exciting a variety of deep-tissue nociceptors. In this study, the relative transfer of biomechanical stresses and strains from the cuff via the skin to the muscle and the somatic tissue layers around bones were investigated. Cuff pressure was applied on the lower leg at three different stimulation intensities (mild pressure to pain). Three-dimensional finite element models including bones and three different layers of deep tissues were developed based on magnetic resonance images (MRI). The skin indentation maps at mild pressure, pain threshold, and intense painful stimulations were extracted from MRI and applied to the model. The mean stress under the cuff position around tibia was 4.6, 4.9 and around fibula 14.8, 16.4 times greater than mean stress of muscle surface in the same section at pain threshold and intense painful stimulations, respectively. At the same stimulation intensities, the mean strains around tibia were 36.4, 42.3 % and around fibula 32.9, 35.0 %, respectively, of mean strain on the muscle surface. Assuming strain as the ideal stimulus for nociceptors the results suggest that cuff algometry is less capable to challenge the nociceptors of tissues around bones as compared to more superficially located muscles.

A critical evaluation of Quintner et al: missing the point

The objective of this article is to critically analyze a recent publication by Quinter, Bove and Cohen, published in Rheumatology, about myofascial pain syndrome and trigger points (Quintner et al., 2014). The authors concluded that the leading trigger point hypothesis is flawed in reasoning and in science. They claimed to have refuted the trigger point hypothesis. The current paper demonstrates that the Quintner et al. paper is a biased review of the literature replete with unsupported opinions and accusations. In summary, Quintner et al. have not presented any convincing evidence to believe that the Integrated TrP Hypothesis should be laid to rest.

Manual therapy ameliorates delayed-onset muscle soreness and alters muscle metabolites in rats

Delayed-onset muscle soreness (DOMS) can be induced by lengthening contraction (LC); it can be characterized by tenderness and movement-related pain in the exercised muscle. Manual therapy (MT), including compression of exercised muscles, is widely used as physical rehabilitation to reduce pain and promote functional recovery. Although MT is beneficial for reducing musculoskeletal pain (i.e. DOMS), the physiological mechanisms of MT remain unclear. In the present study, we first developed an animal model of MT in DOMS; LC was applied to the rat gastrocnemius muscle under anesthesia, which induced mechanical hyperalgesia 2–4 days after LC. MT (manual compression) ameliorated mechanical hyperalgesia. Then, we used capillary electrophoresis time-of-flight mass spectroscopy (CE-TOFMS) to investigate early effects of MT on the metabolite profiles of the muscle experiencing DOMS. The rats were divided into the following three groups; (1) normal controls, (2) rats with LC application (LC group), and (3) rats undergoing MT after LC (LC + MT group). According to the CE-TOFMS analysis, a total of 171 metabolites were detected among the three groups, and 19 of these metabolites were significant among the groups. Furthermore, the concentrations of eight metabolites, including branched-chain amino acids, carnitine, and malic acid, were significantly different between the LC + MT and LC groups. The results suggest that MT significantly altered metabolite profiles in DOMS. According to our findings and previous data regarding metabolites in mitochondrial metabolism, the ameliorative effects of MT might be mediated partly through alterations in metabolites associated with mitochondrial respiration.

Short-term effects of self-massage combined with home exercise on pain, daily activity, and autonomic function in patients with myofascial pain dysfunction syndrome

[Purpose] The aim of the present was to investigate the short-term effects of a program combining self-massage and home exercise for patients with myofascial pain dysfunction syndrome (MPDS). [Subjects and Methods] In this retrospective study, 63 patients were allocated to the experimental (n = 32) and control (n = 31) groups. Both groups received 6 sessions of treatment with physical modalities over the course of two weeks. The experimental group completed an additional program with a combination of self-massage and home exercise. The outcome measurements included a pain scale, pressure pain threshold (PPT), neck disability index (NDI), patient-specific functional scales (PSFS), and heart rate variability (HRV). The interactions between the groups and over time were analyzed using two-way repeated measures ANOVA. [Results] Only the experimental group demonstrated significant improvements in the pain scale with varying conditions. The PPTs of the trigger points increased significantly in the experimental group, and significant functional improvements in NDI and PSFS were observed in the same group. There were significant increases in high-frequency HRV and high-frequency % in the experimental group. [Conclusion] Treatment with physical modalities plus combination of self-massage and home exercise is more effective than the physical modalities treatment alone.

Role of nerve growth factor in pain

Nerve growth factor (NGF) was first identified as a substance that is essential for the development of nociceptive primary neurons and later found to have a role in inflammatory hyperalgesia in adults. Involvement of NGF in conditions with no apparent inflammatory signs has also been demonstrated. In this review we look at the hyperalgesic effects of exogenously injected NGF into different tissues, both human and animal, with special emphasis on the time course of these effects. The roles of NGF in inflammatory and neuropathic conditions as well as cancer pain are then reviewed. The role of NGF in delayed onset muscle soreness is described in more detail than its other roles based on the authors' recent observations. Acute effects are considered to be peripherally mediated, and accordingly, sensitization of nociceptors by NGF to heat and mechanical stimulation has been reported. Changes in the conductive properties of axons have also been reported. The intracellular mechanisms so far proposed for heat sensitization are direct phosphorylation and membrane trafficking of TRPV1 by TrkA. Little investigation has been done on the mechanism of mechanical sensitization, and it is still unclear whether mechanisms similar to those for heat sensitization work in mechanical sensitization. Long-lasting sensitizing effects are mediated both by changed expression of neuropeptides and ion channels (Na channels, ASIC, TRPV1) in primary afferents and by spinal NMDA receptors. Therapeutic perspectives are briefly discussed at the end of the chapter.

A critical evaluation of the trigger point phenomenon

The theory of myofascial pain syndrome (MPS) caused by trigger points (TrPs) seeks to explain the phenomena of muscle pain and tenderness in the absence of evidence for local nociception. Although it lacks external validity, many practitioners have uncritically accepted the diagnosis of MPS and its system of treatment. Furthermore, rheumatologists have implicated TrPs in the pathogenesis of chronic widespread pain (FM syndrome). We have critically examined the evidence for the existence of myofascial TrPs as putative pathological entities and for the vicious cycles that are said to maintain them. We find that both are inventions that have no scientific basis, whether from experimental approaches that interrogate the suspect tissue or empirical approaches that assess the outcome of treatments predicated on presumed pathology. Therefore, the theory of MPS caused by TrPs has been refuted. This is not to deny the existence of the clinical phenomena themselves, for which scientifically sound and logically plausible explanations based on known neurophysiological phenomena can be advanced.

The prevalence of temporomandibular disorders in patients with late whiplash syndrome who experience orofacial pain: a case-control series study

BACKGROUND

The authors conducted a study to compare the frequency of specific temporomandibular disorder (TMD) diagnoses in patients who had late whiplash syndrome (LWS) with that in a control group.

METHODS

The authors recruited 65 patients who had orofacial pain and a previous diagnosis of LWS and 65 age- and sex-matched control patients who had chronic orofacial pain without a history of whiplash injury (WI) for a case-control series study. All patients completed a questionnaire pertaining to the Research Diagnostic Criteria for Temporomandibular Disorders and underwent a clinical examination.

RESULTS

The authors compared the frequency of TMD diagnoses in case patients with that in control patients by using a χ(2) test; they set the α level a priori at .05. The number of patients diagnosed with myofascial pain (MP) and disk displacement with reduction (DDWR) was significantly higher in the case group than in the control group (P = .002 and P = .001, respectively).

CONCLUSIONS

The results of this study show a higher frequency of MP and DDWR in patients with LWS than in patients with chronic orofacial pain and no history of WI. Practical Implications. Clinicians should be knowledgeable about the correlation between WI and TMD so they can inform and treat patients accurately.

Acupuncture therapy: mechanism of action, efficacy, and safety: a potential intervention for psychogenic disorders?

Scientific bases for the mechanism of action of acupuncture in the treatment of pain and the pathogenic mechanism of acupuncture points are briefly summarized. The efficacy and safety of acupuncture therapy is discussed based on the results of German clinical trials. A conclusion on the role for acupuncture in the treatment of psychogenic disorders could not be reached.

Acupuncture for the treatment of urinary incontinence: A review of randomized controlled trials

The aim of this study was to examine the effects of acupuncture on urinary incontinence and to discuss why these acupoints were selected. Seven databases were searched for any randomized controlled trials (RCTs) that investigated the use of acupuncture or acupressure as a treatment for urinary incontinence, and the Cochrane risk of bias tool was utilized to evaluate the risk of bias in each study. Four RCTs met all the inclusion criteria. The results from the selected RCTs failed to demonstrate any statistically significant improvements in urinary incontinence, although acupuncture or acupressure did exhibit favorable effects on overactive bladder symptoms and quality of life, in comparison with other conventional therapies. There have been limited results supporting acupuncture or acupressure as an effective treatment method for urinary incontinence; therefore, further RCTs are required to confirm the effectiveness of acupuncture or acupressure in the treatment of urinary incontinence.

Changes in Pressure Pain Threshold of the Upper Trapezius, Levator Scapular and Rhomboid Muscles during Continuous Computer Work

[Purpose] This study investigated the changes in pressure pain threshold of the upper trapezius, levator scapular, and rhomboid muscles during continuous computer work. [Subjects] Fourteen males and females aged 26-32 years, were recruited. [Methods] A dolorimeter pressure algometer was used to measure the pressure pain threshold of the upper trapezius, levator scapular, and rhomboid muscles, respectively, before computer work and after 15 min, 30 min, and 60 min of computer work. [Results] The pressure pain threshold of the upper trapezius was significantly decreased after 15 min or more of computer work. The pressure pain threshold of the levator scapular was significantly decreased after computer work for 30 min and 60 min. The pressure pain threshold of the rhomboid muscle was significantly decreased after 60 min of computer work. [Conclusion] Continuous computer work could produce much more pain in the levator scapular and rhomboid muscle than the upper trapezius.

Randomized trial of trigger point acupuncture treatment for chronic shoulder pain: a preliminary study

There is evidence for the efficacy of acupuncture treatment for chronic shoulder pain, but it remains unclear which acupuncture modes are most effective. We compared the effect of trigger point acupuncture (TrP), with that of sham (SH) acupuncture treatments, on pain and shoulder function in patients with chronic shoulder pain. The participants were 18 patients (15 women, 3 men; aged 42-65 years) with nonradiating shoulder pain for at least 6 months and normal neurological findings. The participants were randomized into two groups, each receiving five treatment sessions. The TrP group received treatment at trigger points for the muscle, while the other group received SH acupuncture treatment on the same muscle. Outcome measures were pain intensity (visual analogue scale, VAS) and shoulder function (Constant-Murley Score: CMS). After treatment, pain intensity between pretreatment and 5 weeks after TrP decreased significantly (p<0.001). Shoulder function also increased significantly between pretreatment and 5 weeks after TrP (p<0.001). A comparison using the area under the outcome curves demonstrated a significant difference between groups (p=0.024). Compared with SH acupuncture therapy, TrP therapy appears more effective for chronic shoulder pain.

Myoelectrical activity and muscle morphology in a rat model of myofascial trigger points induced by blunt trauma to the vastus medialis

OBJECTIVES

To explore myoelectrical activity and muscle morphology of myofascial trigger points (MTrPs) in an injury model of rats.

METHODS

A total of 24 male SD rats were randomly divided into a control group (group A) and model group (group B). A blunt striking injury and eccentric exercise were applied to the vastus medialis (VM) of rats in group B for 8 weeks. Later, the palpable taut band (TB), local twitch response, myoelectrical activities and morphology in the two groups were examined.

RESULTS

An average of 2.5 (30/12) palpable TBs were detected in the VM in group B compared with none in group A. The MTrPs had two types of abnormal potential. Their amplitudes were significantly higher than those in the control group (p<0.01) but their durations showed no significant differences. A series of reflex contractions appeared in groups A and B in response to external stimulation to the ear. Their amplitude and duration in group B were significantly lower than those in group A. A series of lower fibrillation potentials repeatedly occurred in model MTrPs in group B. The morphology of MTrPs showed abnormal muscle fibres with large round or ellipse shapes in cross-section and enlarged tapering shapes in longitudinal section.

CONCLUSIONS

Active MTrPs can be provoked by repeated blunt injury. Active MTrPs are a group of muscle fibres with abnormal shapes and abnormal myoelectrical potentials. External stimulation provokes low-voltage responses in MTrPs, which is different from the response of normal muscle fibres.

Changes in pressure pain in the upper trapezius muscle, cervical range of motion, and the cervical flexion-relaxation ratio after overhead work

This study examined the changes in pressure pain in the upper trapezius muscle, cervical range of motion, and cervical flexion-relaxation ratio after overhead work. 14 workers were recruited. Pressure pain in the upper trapezius muscle, active cervical range of motion, and cervical flexion-relaxation ratio were measured in all subjects once before and once after overhead work. The pressure-pain threshold of the left upper trapezius muscle was 8.6 ± 2.5 lb before overhead work and 7.3 ± 2.4 lb after overhead work; that of the right upper trapezius muscle was 8.8 ± 2.9 and 7.3 ± 2.8 lb, respectively, revealing a significant decrease in pressure-pain threshold with overhead work. All cervical range of motion measures decreased significantly with overhead work. The cervical flexion-relaxation ratio on the left side was 1.3 ± 0.2 before overhead work and 1.1 ± 0.2 after overhead work; the respective values for the right side were 1.4 ± 0.5 and 1.2 ± 0.3 before and after overhead work, revealing a significant decrease with overhead work. We postulate that overhead work can reduce the pressure-pain threshold in the upper trapezius muscle and cause changes in the cervical range of motion and cervical flexion-relaxation ratio.

Etiology of myofascial trigger points

Myofascial pain syndrome (MPS) is described as the sensory, motor, and autonomic symptoms caused by myofascial trigger points (TrPs). Knowing the potential causes of TrPs is important to prevent their development and recurrence, but also to inactivate and eliminate existing TrPs. There is general agreement that muscle overuse or direct trauma to the muscle can lead to the development of TrPs. Muscle overload is hypothesized to be the result of sustained or repetitive low-level muscle contractions, eccentric muscle contractions, and maximal or submaximal concentric muscle contractions. TrPs may develop during occupational, recreational, or sports activities when muscle use exceeds muscle capacity and normal recovery is disturbed.

Effects of trigger point acupuncture treatment on temporomandibular disorders: a preliminary randomized clinical trial

We compared the effects of trigger point acupuncture with that of sham acupuncture treatments on pain and oral function in patients with temporomandibular disorders (TMDs). This 10-week study included 16 volunteers from an acupuncture school with complaints of chronic temporomandibular joint myofascial pain for at least 6 months. The participants were randomized to one of two groups, each receiving five acupuncture treatment sessions. The trigger point acupuncture group received treatment at trigger points for the same muscle, while the other acupuncture group received sham treatment on the trigger points. Outcome measures were pain intensity (visual analogue scale) and oral function (maximal mouth opening). After treatment, pain intensity was less in the trigger point acupuncture group than in the sham treatment group, but oral function remained unchanged in both groups. Pain intensity decreased significantly between pretreatment and 5 weeks after trigger point (p<0.001) and sham acupunctures (p<0.050). Group comparison using the area under the curve demonstrated a significant difference between groups (p=0.0152). Compared with sham acupuncture therapy, trigger point acupuncture therapy may be more effective for chronic temporomandibular joint myofascial pain.

Involvement of NGF in the rat model of persistent muscle pain associated with taut band

Myofascial pain syndrome (MPS) is an important clinical condition characterized by chronic muscle pain and a myofascial trigger point (MTrP) located in a taut band (TB). However, its pathogenic mechanism is still unclear. We developed an animal model relevant to conditions of MPS, and analyzed the mechanism of the muscle pain in this model. We applied eccentric contraction (EC) to a rat's gastrocnemius muscle (GM) for 2 weeks, and examined the mechanical withdrawal thresholds, histological changes, and expressions and contents of nerve growth factor (NGF). The mechanical withdrawal threshold decreased significantly at the next day of first EC and continued up to 9 days after EC. TBs were palpable at 3 to 8 days after initiation of EC. In EC animals, necrotic and regenerating muscle cells were found significantly more than in control animals. In EC animals, NGF expressions in regenerating muscle cells and NGF contents of GM were significantly higher than control animals. Administration of NGF receptor (TrkA) inhibitor K252a showed significant suppression of mechanical hyperalgesia in EC animals. Repeated EC induced persistent mechanical muscle hyperalgesia associated with TB. NGF expressed in regenerating muscle cells may have an important role in persistent mechanical muscle hyperalgesia which might be relevant to pathogenesis of MPS.

PERSPECTIVE

The present study shows that NGF expressed in regenerating muscle cells is involved in persistent muscular mechanical hyperalgesia. NGF-TrkA signaling in primary muscle afferent neurons may be one of the most important and promising targets for MPS.

Effect of acupuncture depth on muscle pain

Background

While evidence supports efficacy of acupuncture and/or dry needling in treating musculoskeletal pain, it is unclear which needling method is most effective. This study aims to determine the effects of depth of needle penetration on muscle pain.

Methods

A total of 22 healthy volunteers performed repeated eccentric contractions to induce muscle soreness in their extensor digital muscle. Subjects were assigned randomly to four groups, namely control group, skin group (depth of 3 mm: the extensor digital muscle), muscle group (depth of 10 mm: the extensor digital muscle) and non-segmental group (depth of 10 mm: the anterior tibial muscle). Pressure pain threshold and electrical pain threshold of the skin, fascia and muscle were measured at a point 20 mm distal to the maximum tender point on the second day after the exercise.

Results

Pressure pain thresholds of skin group (depth of 3 mm: the extensor digital muscle) and muscle group (depth of 10 mm: the extensor digital muscle) were significantly higher than the control group, whereas the electrical pain threshold at fascia of muscle group (depth of 10 mm: the extensor digital muscle) was a significantly higher than control group; however, there was no significant difference between the control and other groups.

Conclusion

The present study shows that acupuncture stimulation of muscle increases the PPT and EPT of fascia. The depth of needle penetration is important for the relief of muscle pain.

Bradykinin and nerve growth factor play pivotal roles in muscular mechanical hyperalgesia after exercise (delayed-onset muscle soreness)

Unaccustomed strenuous exercise that includes lengthening contraction (LC) often causes delayed-onset muscle soreness (DOMS), a kind of muscular mechanical hyperalgesia. The substances that induce this phenomenon are largely unknown. Peculiarly, DOMS is not perceived during and shortly after exercise, but rather is first perceived after approximately 1 d. Using B(2) bradykinin receptor antagonist HOE 140, we show here that bradykinin released during exercise plays a pivotal role in triggering the process that leads to muscular mechanical hyperalgesia. HOE 140 completely suppressed the development of muscular mechanical hyperalgesia when injected before LC, but when injected 2 d after LC failed to reverse mechanical hyperalgesia that had already developed. B(1) antagonist was ineffective, regardless of the timing of its injection. Upregulation of nerve growth factor (NGF) mRNA and protein occurred in exercised muscle over a comparable time course (12 h to 2 d after LC) for muscle mechanical hyperalgesia. Antibodies to NGF injected intramuscularly 2 d after exercise reversed muscle mechanical hyperalgesia. HOE 140 inhibited the upregulation of NGF. In contrast, shortening contraction or stretching induced neither mechanical hyperalgesia nor NGF upregulation. Bradykinin together with shortening contraction, but not bradykinin alone, reproduced lasting mechanical hyperalgesia. We also showed that rat NGF sensitized thin-fiber afferents to mechanical stimulation in the periphery after 10-20 min. Thus, NGF upregulation through activation of B(2) bradykinin receptors is essential (though not satisfactory) to mechanical hyperalgesia after exercise. The present observations explain why DOMS occurs with a delay, and why lengthening contraction but not shortening contraction induces DOMS.

Effects of tender point acupuncture on delayed onset muscle soreness (DOMS)--a pragmatic trial

Background

Acupuncture is used to reduce inflammation and decrease pain in delayed onset muscle soreness (DOMS). This study investigates the efficacy of acupuncture on the symptoms of DOMS.

Methods

Thirty subjects were assigned randomly to there groups, namely the control, non-tender point and tender point groups. Measurement of pain with full elbow flexion was used as indices of efficacy. Measurements were taken before and after exercise, immediately after treatment and seven days after treatment.

Results

Significant differences in visual analog scores for pain were found between the control group and tender point group immediately after treatment and three days after exercise (P < 0.05, Dunnetts multiple test).

Conclusion

The results show that tender point acupuncture relieves muscle pain of DOMS.

Test-retest reliability of pressure pain threshold measurements of the upper limb and torso in young healthy women

The goal of this study was to determine the intra- and interday reliability of pressure pain thresholds (PPT) in the upper extremity and torso of asymptomatic women. Nineteen healthy women (20-39 years) with no underlying musculoskeletal problems had 3 PPT trials performed on 8 different locations in the upper extremity and torso over 4 consecutive days. The test-retest reliability of PPT values was robust and highly consistent over the 4 days. The PPT intraclass correlations (ICC) were highly consistent and repeatable over the 4 days of testing (day 1: ICC = 0.94; day 2: ICC = 0.96; day 3: ICC = 0.97 and day 4: ICC = 0.96). When compared with baseline measurements obtained on day 1, the PPT values were significantly lower (P < .05) on days 2, 3, and 4 at all 8 locations. Although the PPT test-retest reliability is robust and consistent throughout the 4 days, there appears to be a similar overall decline in the magnitude of the absolute PPT response at each of the 8 locations. A specific explanation for this greater overall sensitivity in PPTs at all 8 locations is lacking; however, a centrally mediated alteration in pressure/pain sensation could contribute to the overall trend observed in this study.

PERSPECTIVE

PPT measurements of the upper limb and torso will be significantly lower with repeated measures over a short period time. A standardized evaluation grid should be included in baseline so as to accurately evaluate the progression in shoulder rehabilitation in women with shoulder dysfunction.

3D-MRI rendering of the anatomical structures related to acupuncture points of the Dai mai, Yin qiao mai and Yang qiao mai meridians within the context of the WOMED concept of lateral tension: implications for musculoskeletal disease

Background

A conceptual model of lateral muscular tension in patients presenting thyroid associated ophthalmopathy (TAO) has been recently described. Clinical improvement has been achieved by using acupuncture on points belonging to the so-called extraordinary meridians. The aim of this study was to characterize the anatomical structures related to these acupuncture points by means of 3D MRI image rendering relying on external markers.

Methods

The investigation was carried out the index case patient of the lateral tension model. A licensed medical acupuncture practitioner located the following acupuncture points: 1) Yin qiao mai meridian (medial ankle): Kidney 3, Kidney 6, the plantar Kidney 6 (Nan jing description); 2) Yang qiao mai meridian (lateral ankle): Bladder 62, Bladder 59, Bladder 61, and the plantar Bladder 62 (Nan jing description); 3) Dai mai meridian (wait): Liver 13, Gall bladder 26, Gall bladder 27, Gall bladder 28, and Gall bladder 29. The points were marked by taping a nitro-glycerin capsule on the skin. Imaging was done on a Siemens Magnetom Avanto MR scanner using an array head and body coil. Mainly T1-weighted imaging sequences, as routinely used for patient exams, were used to obtain multi-slice images. The image data were rendered in 3D modus using dedicated software (Leonardo, Siemens).

Results

Points of the Dai mai meridian – at the level of the waist – corresponded to the obliquus externus abdominis and the obliquus internus abdominis. Points of the Yin qiao mai meridian – at the medial side of the ankle – corresponded to tendinous structures of the flexor digitorum longus as well as to muscular structures of the abductor hallucis on the foot sole. Points of the Yang qiao mai meridian – at the lateral side of the ankle – corresponded to tendinous structures of the peroneus brevis, the peroneous longus, and the lateral surface of the calcaneus and close to the foot sole to the abductor digiti minimi.

Conclusion

This non-invasive MRI investigation has revealed the anatomical relations of acupuncture points belonging to 3 of the so-called extraordinary meridians. We conclude that the clinically developed "WOMED concept of lateral tension" is related to tendino-muscular structures.