The prevalence of myofascial trigger points in hip and thigh areas in anterior knee pain patients

BackgroundAnterior knee pain (AKP) is a widespread problem among young athletes and soldiers. There are many theories on the etiology of AKP but there is little reference to myofascial trigger points (MTrPs) as a possible contributor.AimTo evaluate the association between AKP and prevalence of active and latent MTrPs in the hip and thigh muscles in soldiers.MethodsA cross-sectional study was conducted in the Beer-Sheva military outpatient physical therapy clinic. Subjects were 42 men and 23 women referred for physical therapy, 33 with a diagnosis of AKP (cases) and 32 with upper limb complaints (without AKP, controls). All subjects underwent physical evaluation by an examiner blinded to their identity and medical condition. The following muscles were assessed bilaterally for active or latent MTrPs: rectus femoris (proximal), vastus medialis (middle and distal), vastus lateralis (middle and distal) and gluteus medius (anterior, posterior and distal).ResultsIn six out of eight areas, the cases had a higher prevalence of total active and latent MTrPs than the controls. When summarizing MTrPs by muscle, cases had significantly more MTrPs than controls in each muscle. The largest difference was found in vastus medialis and vastus lateralis; nearly half of the cases had MTrPs in these muscles.ConclusionsSubjects with AKP have a greater prevalence of MTrPs in their hip and thigh muscles than controls, indicating an association between MTrPs and AKP. Further research is necessary to determine whether MTrPs are the cause or the consequence of AKP.     

Proximal myofascial pain in patients with distal complex regional pain syndrome of the upper limb

BackgroundPatients suffering from complex regional pain syndrome (CRPS) endure myofascial-related pain in at least 50% of cases.AimsTo evaluate the association of upper limb CRPS with myofascial pain in muscles that might influence arm or hand pain, and to evaluate whether the paraspinal skin and subcutaneous layers’ tenderness and allodynia are associated with CRPS.MethodsA case-control study comprising 20 patients presenting with upper limb CRPS, and 20 healthy controls matched for sex and age, were evaluated in the thoracic paraspinal area and myofascial trigger points (MTrPs) (infraspinatus, rhomboids, subclavius, serratus posterior superior and pectoralis minor) via a skin rolling test.ResultsThe prevalence of MTrPs in the affected extremity of the subjects was significantly higher than in the right limb of the controls: 45% exhibited active and latent MTrPs in the infraspinatus muscle (χ² = 11.613, p = 0.001); 60% in active and latent MTrPs in the subclavius muscle (χ² = 17.143, p < 0.001); and in the pectoralis minor muscle (χ2 = 13.786, p < 0.001). In addition, 55% of the cases exhibited active and latent MTrPs in the serratus posterior superior muscle (χ² = 15.172, p < 0.001). Significant differences between the groups in skin texture and pain levels (p = 0.01, p < 0.001, respectively) demonstrated that CRPS patients felt more pain, and their skin and subcutaneous layers were much tighter than in the healthy controls.ConclusionThere is a high prevalence of MTrPs in the shoulder and upper thoracic area muscles in subjects who suffer from CRPS. We recommend adding an MTrPs evaluation to the standardized examination of these patients.     

A self-determination theory-based self-myofascial release program in older adults with myofascial trigger points in the neck and back: A pilot study

Purpose: To examine the effectiveness and adherence to a self-determination theory (SDT)-based self-myofascial release (SMR) program in older adults with myofascial trigger points (MTrPs), and to investigate the factors that influence participant behavioral change while conducting the program in a home setting. Methods: An explanatory mixed-method design was used to evaluate a 12-week SDT-based SMR program, including a 4-week group-based education and practice (EP) phase and an 8-week home-based self-management (SM) phase. Pain intensity on palpation and sensitivity to pain were assessed at baseline and the post EP and post SM phase. Focus group interviews were conducted at the post SM phase. Findings: Fifteen participants completed the study. Pain intensity and sensitivity to pain significantly improved at the post SM phase compared with the baseline. Adherence increased during the SM phase compared with that during the EP phase. Four main themes emerged as factors that influenced participant behavioral change: 1) “awareness of the effectiveness”; 2) “a sense of duty to perform the exercise”; 3) “obedience to expert instruction”; and 4) “lack of friendship.” Conclusions: These results support the effectiveness of an SDT-based SMR program for the treatment of MTrPs and in motivating older adults to participate in the program.     

Is occupational or leisure physical activity associated with low back pain? Insights from a cross-sectional study of 1059 participants

BackgroundLow back pain is a highly prevalent and disabling musculoskeletal disorder. Physical activity is widely used as a prevention strategy for numerous musculoskeletal disorders; however, there is still conflicting evidence as to whether physical activity is a protective or risk factor for low back pain or whether activity levels differ between people with and without low back pain.ObjectiveTo investigate the association between low back pain and different types (occupational and leisure) and intensities (moderate and vigorous) of physical activity.MethodsThis is cross-sectional observational study. We included in this study a total of 1059 individuals recruited from a Spanish twin registry with data available on low back pain. Outcome: Self-reported leisure and occupational physical activity were the explanatory variables. The low back pain outcome used in this study was recurrent low back pain.ResultsOur results indicate that leisure physical activity is associated with a lower prevalence of recurrent low back pain. In contrast, occupational physical activity, such as carrying, lifting heavy weight while inclined, awkward postures (e.g. bending, twisting, squatting, and kneeling) are associated with a higher prevalence of recurrent low back pain. There was no statistically significant association between other occupational physical activities, such as sitting or standing, and low back pain.ConclusionLeisure and occupational physical activity are likely to have an opposed impact on low back pain. While leisure physical activity appears to be protective, occupational physical activity appears to be harmful to low back pain. Future longitudinal studies should assist in formulating guidelines addressing specific types and intensity of physical activity aimed at effectively preventing low back pain.     

Topographical mapping and mechanical pain sensitivity of myofascial trigger points in the infraspinatus muscle

Objectives: To screen for the presence of latent and active myofascial trigger points (MTrPs) in patients with unilateral shoulder and arm pain and perform topographical mapping of mechanical pain sensitivity bilaterally in the infraspinatus muscles. Methods: Nineteen patients with unilateral musculoskeletal shoulder pain participated in the study. The area overlying the infraspinatus on each side was divided into 10 adjacent sub‐areas of 1cm², corresponding to the area of a pressure algometer probe. Pressure pain threshold (PPT) was measured in each sub‐area bilaterally in the infraspinatus muscles. Following PPT measurement, an acupuncture needle was inserted into each sub‐area five times in different directions in order to induce local twitch response and/or referred pain. Results: A significantly lower PPT level in the infraspinatus muscle was detected on the painful side compared with the non‐painful side (P=0.001). PPT at midfiber region of the infraspinatus muscles was lower than that at other muscle parts (P<0.05). Multiple, but not single, active MTrPs were found in the infraspinatus muscle on the painful side and there were also multiple latent MTrPs bilaterally in the infraspinatus muscles. PPT at active MTrPs was much lower than the latent MTrPs and again lower than the non‐MTrPs. Conclusions: There exists bilateral mechanical hyperalgesia in patients with unilateral shoulder pain. Further, the association of multiple active MTrPs with unilateral shoulder pain and the heterogeneity of mechanical pain sensitivity distribution suggest a crucial role of peripheral sensitization in chronic myofascial pain conditions. Additionally, the locations of MTrPs identified with dry needling correspond well to PPT topographical mapping, suggesting that dry needling and PPT topographical mapping are sensitive techniques in the identification of MTrPs.     

Management of acute neck pain: A case series describing immediate and short term clinical outcomes following use of the Multifidus Isometric Technique

BackgroundAcute facet capsular entrapment results in sudden onset of pain and reduced ability to perform active cervical motions. The Multifidus Isometric Technique (MIT) is a type of manual therapy intervention theorized to target the entrapped facet capsule and pull the entrapped synovial folds from the facet joint resulting in decreased pain and increased function.PurposeTo describe immediate MIT clinical outcomes for patients with acute neck pain.MethodsConsecutive patients (n = 30; 70% female) with sudden onset of neck pain received MIT within 48 hours of symptom onset. Clinical outcome measures included: 1) 11-point Numeric Pain Rating Scale (NPRS); 2) cervical AROM, and 3) the Neck Disability Index (NDI). Paired-sample t-testing was used to assess for within and between-session changes in outcome measure scores.ResultsWithin-session NPRS improvements were observed during all cervical AROM movements (p < .01), with initial treatment associated with greater improvements on average (M = 2.4 ± 1.6 points) compared to the second treatment (M = 0.6 ± 0.9 points). Similarly, most within-session AROM measures improved during both sessions (p < .01) with greater average improvements observed following the initial treatment session and for cervical rotation to the symptomatic side (M = 26.5 ± 9.6 vs. 8.0 ± 9.7°). Between-session NDI scores improved (M = 15.3 ± 9.8, p < .01) with approximately 60% of patients achieving a minimally clinically important difference of 14 percentage points.DiscussionThe MIT is a potentially beneficial intervention for patients with acute neck pain. Future studies consisting of longer follow-up time points and comparison treatment groups are needed to test MIT effectiveness.     

Reliability and relationship of the fear-avoidance beliefs questionnaire with the shoulder pain and disability index and numeric pain rating scale in patients with shoulder pain

Purpose: The purpose of this study was to determine: 1) the test–retest reliability of Fear-Avoidance Beliefs Questionnaire (FABQ) Work (FABQW) subscale, FABQ Physical Activity (FABQPA) subscale, Shoulder Pain and Disability Index (SPADI) Pain subscale, SPADI Disability subscale, and Numeric Pain Rating scale (NPRS); and 2) the relationship between the FABQPA, FABQW, SPADI pain, SPADI disability, and NPRS after 4 weeks of pragmatically applied physical therapy (PT) in patients with shoulder pain. Design: Prospective, single-group observational design. Methods: Data were collected at initial evaluation, the first follow-up visit prior to the initiation of treatment, and after 4 weeks of treatment. Results: Statistically significant Intraclass Correlation Coefficient (ICC_2,1) values were reported for the FABQPA, FABQW, SPADI Pain, SPADI Disability, and NPRS. A statistically significant moderate relationship between the FABQPA subscale, SPADI subscale, and NPRS could not be established prior to and after 4 weeks of pragmatically applied PT. Statistically significant differences were observed between the initial evaluation and four-week follow-up for the FABQPA, SPADI Pain, SPADI Disability, and NPRS (p < 0.01). Discussion: Since a meaningful relationship between the FABQ, SPADI, and NPRS did not exist, it suggests that the FABQPA may be measuring a metric other than pain. Conclusions: This study suggests that the FABQW may not be sensitive to change over time.     

Myofascial Trigger Points,Pain, Disability,and Sleep Quality in Individuals With Mechanical Neck Pain

ObjectiveThe purpose of this study was to investigate the presence of active myofascial trigger points (MTrPs) in a greater number of muscles than previous studies and the relation between the presence of MTrPs, the intensity of pain, disability, and sleep quality in mechanical neck pain.MethodsFifteen patients with mechanical neck pain (80% women) and 12 comparable controls participated. Myofascial trigger points were bilaterally explored in the upper trapezius, splenius capitis, semispinalis capitis, sternocleidomastoid, levator scapulae, and scalene muscles in a blinded design. Myofascial trigger points were considered active if the subject recognized the elicited referred pain as a familiar symptom. Myofascial trigger points were considered latent if the elicited referred pain was not recognized as a symptom. Pain was collected with a numerical pain rate scale (0-10); disability was assessed with Neck Disability Index; and sleep quality, with the Pittsburgh Sleep Quality Index.ResultsPatients exhibited a greater disability and worse sleep quality than controls (P < .001). The Pittsburgh Sleep Quality Index score was associated with the worst intensity of pain (r = 0.589; P = .021) and disability (r = 0.552; P = .033). Patients showed a greater (P = .002) number of active MTrPs (mean, 2 ± 2) and similar number (P = .505) of latent MTrPs (1.6 ± 1.4) than controls (latent MTrPs, 1.3 ± 1.4). No significant association between the number of latent or active MTrPs and pain, disability, or sleep quality was found.ConclusionsThe referred pain elicited by active MTrPs in the neck and shoulder muscles contributed to symptoms in mechanical neck pain. Patients exhibited higher disability and worse sleep quality than controls. Sleep quality was associated with pain intensity and disability. No association between active MTrPs and the intensity of pain, disability, or sleep quality was found.     

Far-infrared ray patches relieve pain and improve skin sensitivity in myofascial pain syndrome: A double-blind randomized controlled study

ObjectiveMyofascial pain syndrome (MPS) is a common disorder characterized by muscle pain if myofascial trigger points (MTrP) are stimulated. This study evaluated the effectiveness of far-infrared ray (FIR) patches in reducing the severity of pain in patients with MPS.MethodsA double-blind, randomized controlled study involving 125 patients with MPS and 201 MTrPs located in the trapezius muscle. A FIR patch was applied to 98 MTrPs for 24 h in the intervention group (61 patients) and a placebo patch was applied to 91 MTrPs in the control group (57 patients) at the end. Pain intensity was measured using the visual analogue scale (V) while pressure pain threshold (P) and maximal pain tolerance (T) were measured using an algometer before and after treatment.ResultsThe mean age of the patients was 37.16 years old and 67% were female. There was a positive correlation between P and T (p < 0.001). Older Age was associated with higher P and T due to poor skin sensitivity (p < 0.001). V improved significantly in both groups to a similar extent, but only in the intervention group, P and T decreased significantly (which implied better skin sensitivity) (p < 0.05). P and T decreased the most in the female group aged over 35, probably due to thinner skin in this subgroup.ConclusionsFIR and placebo patches were equally effective at relieving pain (with decreased V), but P and T dropped only in the intervention group with FIR patches. This probably resulted from FIR penetrated only to the skin layer and improved skin sensitivity with more blood circulation, but the muscle remained unaffected. Further studies should investigate the effect of longer exposure or higher energy applications.     

Novel method to measure active myofascial trigger point stiffness using ultrasound imaging

Introduction

Myofascial trigger points (MTrPs) are one of the most common and important causes of musculoskeletal pain. Ultrasound is a useful modality in examining musculoskeletal disorders. By applying compressive stress and observing changes in ultrasound images, the elastic modulus (Young's modulus) can be calculated. Our objective was to develop a novel method to distinguish MTrPs from normal tissues.

Prospective Association between Dysmenorrhea and Chronic Pain Development in Community-Dwelling Women

Despite emerging evidence of associations between dysmenorrhea, enhanced pain sensitivity, and functional neuroimaging patterns consistent with chronic pain, it is unknown whether dysmenorrhea is prospectively associated with chronic pain development. Gaining a better understanding of this relationship could inform efforts in prevention of chronic pain. Using data from the national Midlife in the United States cohort, we examined the prospective association between dysmenorrhea and chronic pain development during a 10-year follow-up (starting 10 years after dysmenorrhea was measured) among 874 community-dwelling women aged 25-74 at baseline (when dysmenorrhea was measured). We fit modified Poisson regression models adjusting for sociodemographic, lifestyle and psychosocial factors. Among women who were menstruating at baseline, self-reported dysmenorrhea was associated with a 41% greater (95% confidence interval [CI] = 6%-88%) risk of developing chronic pain. Women with dysmenorrhea also developed chronic pain in more body regions (≥3 regions vs 1-2 regions vs none, odds ratio [OR] = 1.77, 95% CI = 1.18-2.64) and experienced greater pain interference (high-interference vs low-interference vs none, OR = 1.73, 95% CI = 1.15-2.59). Among women who had stopped menstruation at baseline, we did not find evidence of an association between their history of dysmenorrhea and subsequent risk of chronic pain development. Results suggest dysmenorrhea may be a general risk factor for chronic pain development among menstruating women.PerspectiveThis study supports the temporality of dysmenorrhea and chronic pain development in a national female sample. Dysmenorrhea was also associated with developing more widespread and disabling pain among women who were still menstruating. Early management of dysmenorrhea may reduce the development and severity of chronic pain in women, although further research is required to determine whether dysmenorrhea is a causal risk factor or a risk marker of chronic pain.     

Uncovering the biochemical milieu of myofascial trigger points using in vivo microdialysis: An application of muscle pain concepts to myofascial pain syndrome

This article discusses muscle pain concepts in the context of myofascial pain syndrome (MPS) and summarizes microdialysis studies that have surveyed the biochemical basis of this musculoskeletal pain condition. Though MPS is a common type of non-articular pain, its pathophysiology is only beginning to be understood due to its enormous complexity. MPS is characterized by the presence of myofascial trigger points (MTrPs), which are defined as hyperirritable nodules located within a taut band of skeletal muscle. MTrPs may be active (spontaneously painful and symptomatic) or latent (non-spontaneously painful). Painful MTrPs activate muscle nociceptors that, upon sustained noxious stimulation, initiate motor and sensory changes in the peripheral and central nervous systems. This process is called sensitization. In order to investigate the peripheral factors that influence the sensitization process, a microdialysis technique was developed to quantitatively measure the biochemical milieu of skeletal muscle. Biochemical differences were found between active and latent MTrPs, as well as in comparison with healthy muscle tissue. In this paper we relate the findings of elevated levels of sensitizing substances within painful muscle to the current theoretical framework of muscle pain and MTrP development.     

Detecting local twitch responses of myofascial trigger points in the lower-back muscles using ultrasonography

Rha D-w, Shin JC, Kim Y-K, Jung JH, Kim YU, Lee SC. Detecting local twitch responses of myofascial trigger points in the lower-back muscles using ultrasonography.

Objective

To evaluate the role of ultrasonography for detecting local twitch responses (LTRs) of myofascial trigger points (MTrPs) in deeply located lower-back muscles.

Design

Case-control study. Active MTrP was diagnosed in all patients based on the criteria proposed by Travell and Simons in their upper-trapezius or lower-back muscles. One investigator administered trigger point injections while observing LTRs on ultrasonography. The other investigator observed LTRs visually during the procedure.

Setting

University rehabilitation hospital.

Participants

Patients (n=41; mean age, 51.8±11.8y) with MTrPs in the upper-trapezius muscles and patients (n=62; mean age, 56.8±11.9y) with MTrPs in the erector spinae or quadratus lumborum were recruited from April 29 to October 31, 2010.

Interventions

Ultrasound-guided trigger point injection.

Main Outcome Measures

LTR detection rate according to the depth of MTrPs; subjective pain intensity using a visual analog scale before and immediately after the trigger point injection.

Results

In upper-trapezius muscles, all LTRs were detected by means of both ultrasonographic and visual inspection. In the lower-back muscles, many LTRs were detected only on ultrasonography during the trigger point injection. For deep muscles, ultrasound helped identify LTRs that were not detected by using visual assessment. Pain was alleviated more significantly in the group with LTRs during trigger point injections compared with the group without LTRs.

Conclusions

These findings suggest that ultrasonography was useful for detecting LTRs of MTrPs, especially for LTRs in the deep muscles. Ultrasound guidance may improve the therapeutic efficacy of trigger point injection for treating MTrPs in the deep muscles.     

Dry needling in chronic abdominal wall pain of uncertain origin

Background

Abdominal wall pain is considered as pain that arises from the abdominal muscles rather than the underlying viscera or the spine. It is frequently overlooked and is often misdiagnosed, as these patients continue to suffer with pain. Many such patients would have even been subjected to a psychiatric evaluation in view of the absence of any ostensible clinical cause for the pain. In this study, we describe the role of myofascial trigger points in the abdominal wall pain that could be a cause of chronic pain and present our findings of pain relief by dry needling technique.

Women With Dysmenorrhea Are Hypersensitive to Experimental Deep Muscle Pain Across the Menstrual Cycle

Primary dysmenorrhea is a common painful condition in women that recurs every month across the reproductive years. The recurrent nociceptive input into the central nervous system that occurs during menstruation each month in women with dysmenorrhea is hypothesized to lead to increased sensitivity to painful stimuli. We investigated whether women with primary dysmenorrhea are hyperalgesic to deep muscle pain induced by a cleanly nociceptive method of hypertonic saline injection. Pain stimulation was applied both within an area of referred menstrual pain (lower back) and at a remote site outside of referred menstrual pain (forearm) in 12 healthy women with severe dysmenorrhea and 9 healthy women without dysmenorrhea, at 3 phases of the menstrual cycle: menstruation and follicular and luteal phases. Women rated their pain severity on a 100-mm visual analog scale every 30 seconds after injection until the pain subsided. In both groups of women, menstrual cycle phase had no effect on the reported intensity and duration of muscle pain. However, women with dysmenorrhea had increased sensitivity to experimental muscle pain both at the site of referred pain and at a remote nonpainful site, as assessed by peak pain severity visual analog scale rating, area under the visual analog scale curve, and pain duration, compared to women without dysmenorrhea. These data show that women with severe primary dysmenorrhea, who experience monthly menstrual pain, are hyperalgesic to deep muscle pain compared to women without dysmenorrhea.     

Effectiveness of trigger point dry needling for multiple body regions: a systematic review

Background: Trigger point dry needling (TDN) is commonly used to treat musculoskeletal pain related to myofascial trigger points (MTrPs). To date, no systematic review of high-quality randomised controlled trials (RCTs) investigating TDN to multiple body regions exists.

Purpose: The aim of this review is to determine the effectiveness of TDN based on high-quality RCTs for all body regions.

Methods: To ensure thorough reporting, Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed as the methodological basis for this systematic review. PubMed, Physiotherapy Evidence Database (PEDro), Cinahl, Cochrane and reference lists were searched for the years 2000–2014 and the terms ‘TDN’, ‘dry needling NOT trigger point’, ‘functional dry needling’ and ‘intramuscular manual therapy’. Inclusion criteria: RCTs with PEDro scores 6–10 investigating TDN. Exclusion criteria: duplicates, non-human participants, non-English language, exclusive focus on acupuncture or medicinal injections. Three investigators searched databases, applied criteria, read and assigned PEDro scores to every RCT. Nineteen studies met the criteria. As compared to either baseline or control groups, significant differences were found for pain (14 studies), range of motion (ROM) (five studies) and at least one item on function and quality of life measures (six studies).

Limitations: This review was limited by inclusion criteria, timeframe, language and databases searched.

Conclusion: The majority of high-quality studies included in this review show measured benefit from TDN for MTrPs in multiple body areas, suggesting broad applicability of TDN treatment for multiple muscle groups. Further high-quality research is warranted to standardise TDN methods to determine clinical applicability.     

Prevalence of Dysmenorrhea in University Students in Turkey: Effect on Daily Activities and Evaluation of Different Pain Management Methods

This study was conducted to determine the following among a group of female university students: the prevalence of dysmenorrhea; pain severity ratings; methods used to manage dysmenorrhea; and the effect of dysmenorrhea on daily activities, school attendance, and ability to communicate with friends. This cross-sectional study was conducted between December 2009 and February 2010 at a public university located in Istanbul, in the northwest area of Turkey. The study group included 1515 female students. Data were collected from the female students in the study group using a self-report questionnaire; the severity of dysmenorrhea was determined with the visual analog scale. The data were examined with mean, percentages, chi-square analysis, and logistic regression. The prevalence of dysmenorrhea in the study group was 85.7%. Of this group of subjects with dysmenorrhea, 30.4% described their menstrual pain as severe, 49.8% as moderate, and 19.8% as mild. The mean severity of pain among the students was 6.33 ± 2.32 on the VAS. The majority of participants who experienced moderate or severe pain regularly used analgesics for pain management, and participants who experienced severe pain used analgesics before the beginning of menstruation. Participants who experienced moderate pain used herbal tea, massage, heat application, rest, and distraction for pain management. Participants who experienced severe pain consulted a physician and that a significant difference existed between the dysmenorrhea rating groups in this regard (p < .001). Severe pain was significantly associated with school absenteeism and limitations in social activities/functioning (p < .001). Dysmenorrhea is highly prevalent among university students and is related to school absenteeism, ability to participate in and enjoy daily activities, and limitations in social activities/functioning.     

Traditional Chinese Medicine acupuncture and myofascial trigger needling: The same stimulation points?

BackgroundAcupuncture originates in China, and its effectiveness has been well documented in musculoskeletal pain disorders and other conditions. A widely accepted contemporary medical treatment option for myofascial pain is trigger point needling. Although there are many differences between Traditional Chinese Medicine acupuncture theory and the myofascial trigger point needling framework, it is argued that the stimulation sites for these two needling modalities are similar.DiscussionIn this paper we examined the correspondence between Traditional Chinese Medicine acupoints and myofascial trigger points. Based on this correspondence, we considered exploration of Ah-shi points from four aspects: pain recognition, distal Ah-shi points, Anti-Ah-shi points, and management approaches.Summary: The extent of correspondence is influenced by definitions of acupoints. Myofascial trigger points are significantly correlated to Traditional Chinese Medicine acupoints, including primary channel acupoints, extra acupoints, and Ah-shi points. Considering the correlation between MTrPs and acupoints and the rarely-studied research area of Ah-shi points, it may be reasonable to incorporate research findings of myofascial trigger points into further investigations into Ah-shi points. Correspondence between myofascial trigger points and acupoints enhances contemporary understanding of the mechanism of action of acupuncture, and may serve to facilitate increased integration of acupuncture into clinical management.