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

Blood Flow of the Infraspinatus Muscle in Individuals With and Without Shoulder Pain and Myofascial Trigger Points: A Color Doppler Ultrasound and Reliability Study

OBJECTIVES

Myofascial trigger points (MTrPs) are potential contributors to shoulder pain and can lead to local ischemia and hypoxia, thus causing pain. Color Doppler ultrasound (US) has been used to examine the vascular environment around MTrPs, but has not been used to examine blood flow impairments in patients with shoulder pain and MTrPs. The reliability of color Doppler US for measuring infraspinatus muscle blood flow also has not been established. This study aimed to investigate differences in blood flow between individuals with and without shoulder pain and the reliability of Doppler US for measuring infraspinatus muscle blood flow.

METHODS

Forty participants were enrolled, 20 with shoulder pain and MTrPs and 20 without. Color Doppler US examination was performed twice on each participant to measure peak systolic velocity (PSV), end-diastolic velocity (EDV), resistive index (RI), and pulsatile index (PI) of the infraspinatus muscle.

RESULTS

The symptomatic participants had significantly higher PSV (ie, impaired blood flow) than the asymptomatic participants. There were no significant between-group differences in EDV, RI, and PI. The results also demonstrated good-to-excellent intra-rater reliability for color Doppler US measurements of PSV, EDV, RI, and PI for both groups.

CONCLUSION

This study demonstrated differences in blood flow near MTrPs in the infraspinatus muscle between individuals with and without shoulder pain. It also established good-to-excellent reliability of color Doppler US in measuring infraspinatus muscle blood flow. These findings suggest color Doppler US is a useful tool to identify vascular impairments for shoulder pain associated with MTrPs.

Mouth opening, jaw disability, neck disability, pressure pain thresholds, and myofascial trigger points in patients with disc displacement with reduction: A descriptive and comparative study

OBJECTIVE

To assess jaw and neck function, pressure pain threshold (PPT), and the presence of trigger points (TrPs) in disc displacement with reduction (DDWR) subjects compared to healthy subjects.

METHODS

One hundred DDWR subjects and 100 matched controls were studied. Clinical evaluations included demographic data, range of motion, jaw and neck disability, PPT, and muscle TrPs.

RESULTS

DDWR subjects have limited pain-free opening limitation (p < 0.001), jaw and neck disability limitation (p < 0.001), and higher presence of active and latent TrPs limitation (p < 0.001) compared to healthy subjects.

CONCLUSION

DDWR subjects present a limited pain-free mouth opening, higher jaw and neck disability, lower PPT, and major presence of active and latent TrPs compared to healthy subjects. Cervical spine and TMJ evaluation and treatment should be considered in DDWR patients.

The effect of joint position sense therapy on chronic shoulder pain with central sensitization

BACKGROUND

Chronic shoulder pain is a common musculoskeletal problem associated with unreleased pain and functional dysfunction that can evolve into central sensitization. Some forms of manual therapy may exacerbate pain and central sensitization. This study investigated the impact of joint position sense therapy (JPST), a moderate joint proprioception training technique, on central sensitization, shoulder functional dysfunction, and pain in patients with chronic shoulder pain compared with more intense exercises or aggressive manual therapies.

METHODS

We assessed the pressure pain threshold (PPT) in 30 patients with and 30 patients without chronic shoulder pain. The assessment focused on 4 muscle sites: deltoid, upper trapezius, brachioradialis, and tibialis anterior. Thirty patients with chronic shoulder pain were randomly divided into the JPST and control groups. The JPST group underwent additional shoulder joint position-sense training. The efficiency outcomes were the disabilities of the arm, shoulder, and hand questionnaire, visual analog scale (VAS), and PPT, evaluated at baseline and after the intervention.

RESULTS

Significant differences were observed in the PPT values at the brachioradialis (P < .05), deltoid (P < .01), and trapezius (P < .001) among the non-chronic and chronic groups, but not in the tibialis anterior muscle (P > .05). Although both control and JPST interventions effectively improved the disabilities of the arm, shoulder, and hand questionnaire score, pain intensity, and PPT values in the upper limb, the outcomes in the JPST group were significantly different from those in the control group.

CONCLUSIONS

Generalized hyperalgesia changes limited to the upper limbs were observed in patients with chronic shoulder pain. JPST has beneficial effects on pain control and functional dysfunction in patients with chronic shoulder pain.

Anatomical analysis of the motor endplate zones of the suprascapular nerve to the infraspinatus muscle and its clinical significance in managing pain disorder

Myofascial pain syndrome caused by myofascial trigger points is a musculoskeletal disorder commonly encountered in clinical practice. The infraspinatus muscle is the region most frequently involved in the myofascial pain syndrome in the scapular region. The characteristics of the myofascial trigger points are that they can be found constantly in the motor endplate zone. However, localizing myofascial trigger points within the motor endplate zone and establishing an accurate injection site of the infraspinatus muscle has been challenging because the anatomical position of the motor endplate zone of the infraspinatus muscle is yet to be described. Therefore, this cadaveric study aimed to scrutinize the motor endplate zone of the infraspinatus muscle, propose potential myofascial trigger points within the muscle, and recommend therapeutic injection sites. Twenty specimens of the infraspinatus muscle for nerve staining and 10 fresh frozen cadavers for evaluation of the injection were used in this study. The number of nerve branches penetrating the infraspinatus muscle and their entry locations were analyzed and photographed. Modified Sihler's staining was performed to examine the motor endplate regions of the infraspinatus muscle. The nerve entry points were mostly observed in the center of the muscle belly. The motor endplate was distributed equally throughout the infraspinatus muscle, but the motor endplate zone was primarily identified in the B area, which is approximately 20-40% proximal to the infraspinatus muscle. The second-most common occurrence of the motor endplate zone was observed in the center of the muscle. These detailed anatomical data would be very helpful in predicting potential pain sites and establishing safe and effective injection treatment using botulinum neurotoxin, steroids, or lidocaine to alleviate the pain disorder of the infraspinatus muscle.

Sonoanatomy and an ultrasound scanning protocol of the intramuscular innervation pattern of the infraspinatus muscle

INTRODUCTION

Botulinum neurotoxin injection is a valuable treatment method for patients with myofascial pain syndrome in the infraspinatus muscle. However, there is no botulinum neurotoxin injection guideline, and the most appropriate injection site based on topographical anatomic information for this injection to effectively treat myofascial pain syndrome in the infraspinatus muscle is unclear. The purpose of this study was to evaluate the intramuscular nerve terminal of the infraspinatus muscle and to suggest the most efficient botulinum neurotoxin injection sites.

METHODS

This study used 5 formalin-embalmed and 10 fresh frozen cadavers with a mean age of 78.9 years. Sihler's staining was applied to evaluate the intramuscular nerve terminal of the infraspinatus muscle. The ultrasound scanning of the infraspinatus muscle was performed based on the surface landmarks and internal structures near the scapular region.

RESULTS

The intramuscular nerve terminal was mostly observed in the medial third area of the infraspinatus muscle. The deltoid tubercle, inferior angle, and acromion of the scapula are useful as surface landmarks to scan the infraspinatus muscle.

DISCUSSION

The proposed injection sites based on the intramuscular nerve terminal and surface landmarks can be regarded as accurate locations to reach the cluster area of the intramuscular nerve terminal and each compartment of the infraspinatus muscle to manage the myofascial pain syndrome in the infraspinatus muscle.

Application of Acupuncture for Shoulder Pain Over the Past 22 Years: A Bibliometric Analysis

Purpose

Acupuncture is widely used to relieve shoulder pain. A survey was conducted in order to recognize hotspots and frontiers of acupuncture for shoulder pain from the year 2000-2022.

Methods

The Web of Science Core Collection was used to collect literature related to acupuncture therapy for shoulder pain, which spanned January 2000 to August 2022. The number of publications yearly, countries/institutions, journals, and keywords was analyzed and visualized in shoulder pain with acupuncture therapy by CiteSpace v.5.7.R5.

Results

We totally analyzed 214 articles that met the inclusion criteria. The overall trend of publication volume continues to increase. The most productive authors in the field were César Fernández las Peñas and José L Arias-Buría, and the most influential author was Green S. Kyung Hee University and the People's Republic of China had the highest volume of publications, respectively. The most influential journal is Pain with high citation and impact factor. The hot keywords were "acupuncture", "shoulder pain", "dry needling", "randomized trial", and "injection". The research frontier in acupuncture for treating chronic shoulder pain was mainly "mechanism".

Conclusion

Over the last 22 years, the findings of this bibliometric analysis have provided research trends and frontiers in clinical research on acupuncture therapy for patients with shoulder pain, which identifying hot topics and exploring new directions for the future may be helpful to researchers. Studying mechanisms underlying acupuncture therapy for shoulder pain remains a focus of future research.

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.

Immediate Effects of Adding Dry Needling to Thoracic Manipulation and Exercise in Cervical Range of Motion for Adults With Neck Pain: A Randomized Clinical Trial

OBJECTIVE

The purpose of this study was to determine the immediate effects of adding dry needling (DN) to thoracic spine manipulation and neck-specific exercise in individuals with neck pain.

METHODS

Forty-two participants with neck pain were randomized to either the true (n = 21) or sham (n = 21) DN groups, receiving treatment on the initial visit and 2 to 3 days later. Outcomes were assessed on day 1, both at baseline and immediately after the initial treatment, at the second treatment 2 to 3 days later, and at the final visit 5 to 7 days after visit 2. Primary outcomes were Neck Disability Index (NDI) (0-50) and current pain via numeric pain rating scale (0-10). Secondary outcomes were cervical range of motion, pain pressure threshold, and global rating of change.

RESULTS

Repeated measures analysis of covariance with baseline value as covariate revealed no significant difference in NDI scores at either follow-up time point with adjusted mean differences (95% confidence interval) of -0.11 (-2.70 to 2.48) and 0.31 (-1.96 to 2.57). There were no between-group differences in pain at any time point via Independent-Samples Median Test (P value range of .54-1.0). Secondary outcome measures were similarly not statistically different between groups except for immediate improvements in rotation to the side opposite of pain, which favored DN, with an adjusted mean difference (95% confidence interval) of 7.85 (3.54-12.15) degrees.

CONCLUSION

The addition of DN to thoracic spinal manipulation and neck-specific exercise did not affect improvements in NDI score or numeric pain rating scale but showed an increase in cervical range of motion.

Pressure pain threshold mappings of the infraspinatus muscle in chronic unilateral shoulder pain patients do not reflect generalized hypersensitivity

OBJECTIVES

Increased mechanical sensitivity has been observed on the unaffected side in chronic pain conditions, suggesting generalized or widespread hypersensitivity. However, this cannot be considered as a universal response since this hypersensitivity is inconsistent across muscle pain pathologies. The aim of this study was to assess generalized hypersensitivity in chronic unilateral shoulder pain, using pressure pain threshold (PPT) mappings of the infraspinatus muscle. The proposed evaluation is based on the assessment of PPT on a limited subset of sites, reducing potential habituation or sensitization effects.

METHODS

Twenty-nine patients with unilateral shoulder pain (USP) and twenty-seven healthy volunteers were recruited. PPT was assessed using a manual pressure algometer. Six sites distributed over the infraspinatus muscle were assessed, and three repetitions were performed at each site. Mappings were derived using two-dimensional interpolation.

RESULTS

Lower PPT values were found in the symptomatic side in comparison with the asymptomatic side at all assessment sites (estimated difference: 1.42 ± 0.10 kgf/cm², p < 0.001), but there were no differences among the asymptomatic side of USP patients and any of the sides in healthy volunteers (largest estimated difference: 0.17 ± 0.28 kgf/cm², p = 0.927). Furthermore, the medial region of the infraspinatus muscle showed higher mechanical sensitivity in both healthy volunteers and USP patients.

CONCLUSIONS

These results suggest that USP does not induce generalized hypersensitivity, in contrast with previously reported findings. Physiotherapists could take these results into account for the assessment and treatment of patients with USP.

Profiling and Association over Time between Disability and Pain Features in Patients with Chronic Nonspecific Neck Pain: A Longitudinal Study

OBJECTIVES

To longitudinally investigate the relationships between neck/arm disability and pain profile measures in individuals with chronic nonspecific neck pain (NSNP) at baseline, one month, and six months after a standardized physiotherapy intervention. A secondary aim was to compare pain sensitivity of individuals with chronic NSNP at baseline to healthy controls.

METHODS

A total of sixty-eight individuals with chronic NSNP and healthy controls were recruited. Neck disability index (NDI), the 11-item disabilities of the arm, shoulder, and hand questionnaire (QuickDASH), temporal summation (TS), pressure pain thresholds (PPTs), pain intensity and pain extent were assessed in individuals with chronic NSNP. For the cross-sectional assessment, TS and PPTs were compared to healthy controls.

RESULTS

After following a standardized physiotherapy intervention, local and distal PPTs to the neck region decreased at one and six month follow-ups, respectively. Pain extent decreased at one and six months. Furthermore, a positive correlation between neck/arm disability and pain intensity was found at baseline, whereas moderate positive correlations (e.g., between NDI and pain extent) at baseline, one and six month follow-ups and negative correlations at six months (e.g., between arm disability and PPTs) were found.

DISCUSSION

Overall, these findings indicate that pain sensitivity can worsen following treatment despite reduced pain extent and unchanged neck disability and pain intensity scores over a six-month period in individuals with chronic NSNP.

Dry needling has lasting analgesic effect in shoulder pain: a double-blind, sham-controlled trial

Supplemental Digital Content is Available in the Text.

Dry needling has analgesic effects in shoulder pain associated with myofascial pain syndrome. The analgesic effects last for up to 1 week.

Introduction:

Myofascial pain syndrome (MPS) affects most patients with chronic shoulder pain. Dry needling (DN) is a common treatment for MPS, but its temporal pattern and sensory effects remain unknown.

Objectives:

We evaluated in a randomized, sham-controlled study the pattern of analgesic efficacy and local sensory changes of a single session of DN for MPS in patients with chronic shoulder pain.

Methods:

Patients with chronic shoulder pain were randomized into active (n = 20) or sham (n = 21) groups. A single DN was performed by a researcher blinded to group assignment and pain outcomes. Pain intensity was assessed by the numeric rating score, and sensory thresholds were evaluated with a quantitative sensory testing protocol, including the area of tactile sensory abnormalities 7 days before needling, right before, and 7 days after the intervention.

Results:

Dry needling led to significant larger pain intensity reduction (from 6.30 ± 2.05 to 2.40 ± 2.45 in the active group; P = 0.02, effect size = −1.3 (95% CI [−2.0 to −0.68]); (number necessary to treat = 2.1). Pain reduction scores were significantly different on the second day after needling and persisted so until the seventh day and were accompanied by improvement in other dimensions of pain and a decrease in the area of mechanical hyperalgesia in the active DN group alone (P < 0.05).

Conclusion:

Active trigger points DN provided analgesic effects compared with sham and decreased the area of local mechanical hyperalgesia. These findings have practical clinical implications and may provide mechanistic insights behind MPS.

Current advances and novel research on minimal invasive techniques for musculoskeletal disorders

The present review summarized the current advances and novel research on minimal invasive techniques for musculoskeletal disorders. Different invasive approaches were proposed in the physical therapy field for the management of musculoskeletal disorders, such as ultrasound-guided percutaneous needle electrolysis, dry needling, acupuncture and other invasive therapy techniques, discussing about their worldwide status, safety and interventional ultrasound imaging. Indeed, dry needling may be one of the most useful and studies invasive physical therapy applications in musculoskeletal disorders of different body regions, such as back, upper limb, shoulder, arm, hand, pelvis, lower limb, neck, head, or temporomandibular joint, and multiple soreness location disorders, such as fibromyalgia. In addition, the assessment and treatment by acupuncture or electro-acupuncture was considered and detailed for different conditions such as plantar fasciitis, osteoarthritis, spasticity, myofascial pain syndrome, osteoporosis and rheumatoid arthritis. As an increasing technique in physical therapy, the use of ultrasound-guided percutaneous needle electrolysis was discussed in injuries of the musculoskeletal system and entrapment neuropathies. Also, ultrasound-guided percutaneous neuromodulation was established as a rising technique combined with ultrasound evaluation of the peripheral nerve system with different clinical applications which need further studies to detail their effectiveness in different musculoskeletal conditions. Thus, invasive physical therapy may be considered as a promising approach with different novel applications in several musculoskeletal disorders and a rising use in the physiotherapy field.

The Context Matters: A Retrospective Analysis of Life Stage at Chronic Pain Onset in Relation to Pain Characteristics and Psychosocial Outcomes

BACKGROUND

Developmental life stage at chronic pain onset differs among chronic pain patients. Although pain affects multiple life domains, it is unknown whether the timing of chronic pain onset relates to pain characteristics and psychosocial outcomes. The purpose of this retrospective study was to investigate differences in pain characteristics and psychosocial outcomes in patients at different developmental life stages at chronic pain onset.

METHODS

Cross-sectional baseline data from the Swedish Quality Registry for Pain Rehabilitation (2009 to 2016) were used, selecting the middle-aged patients (45-65 years, n=6225) reporting chronic nonmalignant pain. Patients were categorized into three groups, depending on their developmental life stage at chronic pain onset: early onset (age ≤30 years), intermediate onset (age 31-45 years), and late onset (age ≥46 years). Pain characteristics and psychosocial outcomes were assessed with validated self-reported measures.

RESULTS

One-way MANCOVA indicated differences in number of pain locations and psychosocial outcomes among the groups. Post hoc analysis showed differences in the trends for how groups differed on outcome domains. Overall, patients with earlier chronic pain onset showed significantly poorer psychosocial outcomes and more spreading of pain.

CONCLUSION

Developmental life stage at chronic pain onset is associated with different pain outcomes. Pain onset early in life is linked to worse outcomes in multiple domains, pointing to a need for identifying these patients early.

Acupotomy Alleviates Energy Crisis at Rat Myofascial Trigger Points

The aim of this study was to determine the effects of acupotomy on energy crises in rat trigger points (TrPs) by measuring mechanical pain thresholds (MPTs) and levels of acetylcholinesterase (AChE), free sarcoplasmic calcium (Ca²⁺), adenosine 5'-triphosphate (ATP), adenosine 5'-monophosphate (AMP), substance P (SP), and calcitonin gene-related peptide (CGRP) in rat muscle TrP tissue. Male Sprague Dawley rats (n = 32) were randomly divided into four groups: control, TrP, acupotomy, and lidocaine injection. Enzyme-linked immunosorbent assays were used to measure AChE, and free sarcoplasmic Ca²⁺ concentrations were determined by fluorescent staining with Fura-2 AM; high-performance liquid chromatography was used to measure ATP and AMP, and SP and CGRP were evaluated by immunohistochemistry. Compared with the control group, free sarcoplasmic Ca²⁺, AMP, SP, and CGRP were higher in the model group, while MPT, AChE, and ATP were lower. Treatment with acupotomy or lidocaine injection reduced free sarcoplasmic Ca²⁺, SP, and CGRP and increased MPTs and AChE levels compared with the model group. However, only acupotomy also led to decreased AMP and increased ATP levels relative to the model group. We conclude that acupotomy can alleviate energy crises at TrPs.

The protocol for a multisite, double blind, randomized, placebo-controlled trial of axillary nerve stimulation for chronic shoulder pain

BACKGROUND

Shoulder impingement syndrome is one of the most common causes of shoulder pain, accounting for approximately 30% of all shoulder pain. Approximately 35% of patients with shoulder impingement syndrome are refractory to conservative treatment. For patients who fail conservative treatment, there is no established treatment to successfully treat their chronic pain. Prior randomized control trials have demonstrated efficacy for the use of a single lead intramuscular peripheral nerve stimulation of the axillary nerve at the motor points of the deltoid muscle for treatment of hemiplegic shoulder pain. This is the first controlled trial to utilize the same novel technology to treat shoulder impingement syndrome outside of the stroke population.

METHODS

This is a dual-site, placebo-controlled, double-blinded, randomized control trial. Participants will be randomized to two treatment groups. The intervention group will be treated with active peripheral nerve stimulation of the axillary nerve of the affected shoulder and the control group will be treated with sham peripheral nerve stimulation of the axillary nerve of the affected shoulder. Both groups will receive a standardized exercise therapy program directed by a licensed therapist.

DISCUSSION

This study protocol will allow the investigators to determine if this novel, non-pharmacologic treatment of shoulder pain can demonstrate the same benefit in musculoskeletal patients which has been previously demonstrated in the stroke population.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT03752619. Registered on 26 November 2018.

The effectiveness of trigger point treatment in rotator cuff pathology: A randomized controlled double-blind study

BACKGROUND

Studies have emphasized the importance of the presence of myofascial trigger points (MTrPs) in patients with rotator cuff pathologies and the high frequency of MTrPs in rotator cuff muscles.

OBJECTIVE

Evaluate the effectiveness of the treatment of active MTrPs in patients with rotator cuff pathologies.

METHODS

Fifty-three patients with rotator cuff tear were randomized into two groups. All patients received the same standard conservative treatment twice a week for 6 weeks. Patients in Group 1 additionally received ischemic compression (IC) of MTrPs. Pain, range of motion (ROM), function, and anxiety and depression were assessed. MTrPs in rotator cuff muscles were assessed manually, and the number of MTrPs on the shoulder complex was counted.

RESULTS

There were no significant differences between the groups in terms of changes in resting/activity/night pain, ROM, function, or anxiety and depression (p> 0.05). Pain scores improved only in Group 1. However, the total number of MTrPs was significantly decreased in Group 1 (p= 0.001).

CONCLUSION

A six-week course of IC helps treat active MTrPs. A standard conservative treatment program reduced pain and increased function; the addition of MTrP treatment did not improve clinical outcomes in patients with rotator cuff pathologies.

Understanding Acupoint Sensitization: A Narrative Review on Phenomena, Potential Mechanism, and Clinical Application

As part of traditional Chinese medicine, acupoints are considered a dynamic functional area, which can reflect the internal condition of the body. When the body is suffering from disease or injury, corresponding acupoints are believed to be activated and manifest in several sensitized forms, including expansion of the receptive field, pain sensitization, and heat sensitization. Such phenomena are believed to gradually disappear concomitantly with recovery from the disease. Acupoint states are therefore changeable according to health status, a phenomenon known as acupoint sensitization. This review aims to provide an overview of acupoint sensitization based on existing research results and determine priorities for future research. Systematic literature retrieval was conducted in Medline, Embase, Cochrane Library, CINAHL, and AMED from inception to 18 July 2018. Current evidence from research findings to date indicate that acupoint sensitization is based on neurogenic inflammation and that stimulation of sensitized acupoints presents a potential trend of generating a better clinical effect when compared with stimulation of unsensitized points.

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

BACKGROUND

Anterior 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.

AIM

To evaluate the association between AKP and prevalence of active and latent MTrPs in the hip and thigh muscles in soldiers.

METHODS

A 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).

RESULTS

In 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.

CONCLUSIONS

Subjects 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.

Prognostic effect of pain sensitization in patients with de Quervain's tenovaginosis receiving corticosteroid injection

We investigated the influence of pain sensitization on the prognosis of de Quervain's tenovaginosis after a local corticosteroid injection. One hundred and fifteen patients with de Quervain's tenovaginosis who were treated with corticosteroid injection were recruited. We initially measured pain sensitization by assessing the patients' pressure pain thresholds in the mid-dorsal forearm and by administering a Pain Sensitivity Questionnaire. The pain score using a visual analogue scale, the result of Eichhoff's test, and the Disability of the Arm, Shoulder, and Hand (DASH) questionnaire were assessed at baseline and at 6 and 24 weeks after the injection. The DASH scores at 6 weeks correlated slightly with higher Pain Sensitization Questionnaire scores, and the DASH scores at 24 weeks correlated moderately with higher Pain Sensitization Questionnaire scores and lower pressure pain thresholds. Lower pressure pain thresholds, higher Pain Sensitization Questionnaire scores, and heavy manual work were independently associated with a higher likelihood of persistent symptoms and signs after a local corticosteroid injection for de Quervain's tenovaginosis. Level of evidence: III.

Allodynography: Reliability of a New Procedure for Objective Clinical Examination of Static Mechanical Allodynia

Objective

There is a need for reliable and valid clinical assessment tools for quantifying allodynia in neuropathic pain. Allodynography has been proposed as a useful standardized procedure for clinical assessment of mechanical allodynia. This study (www.clinicaltrials.gov NCT02070367) undertook preliminary investigation of the measurement properties of allodynography, a new standardized clinical examination procedure for mapping the area of cutaneous allodynia.

Methods

Persons with pain in one upper extremity after complex regional pain syndrome, a peripheral nerve injury, or who had recently experienced a hand fracture were recruited for assessment of static mechanical allodynia (based on perception of a 15g force stimulus delivered by Semmes-Weinstein monofilament #5.18 as painful) by two raters at baseline; the assessment was repeated one week later.

Results

Single-measures estimates suggested inter-rater reliability for allodynography was excellent at an intraclass correlation coefficient (ICC) of 0.97 (N = 12); test–retest reliability was also excellent at ICC = 0.89 (N = 10) for allodynography (P &lt; 0.001 for both). Confidence intervals’ lower bounds confirm inter-rater reliability as excellent (0.90) but were less definitive for test–retest (0.59).

Conclusions

This preliminary study supports the inter-rater and test–retest reliability of allodynography. Studies on larger samples in multiple contexts and reporting other measurement properties are warranted.

The Prognostic Value of Pain Sensitization in Patients With Lateral Epicondylitis

PURPOSE

Pain sensitization is a contributing factor to conditions of chronic pain. The aim of this study was to evaluate the influence of pain sensitization on the prognosis of lateral epicondylitis (LE) treated by self-stretching exercises and the use of a counterforce brace.

METHODS

We enrolled 131 patients who presented with isolated LE symptoms for less than 6 months. We initially measured pain sensitization by assessing patients' pressure pain thresholds (PPTs) in the contralateral middorsal forearm and administering a pain sensitization questionnaire (PSQ). For outcome assessments, we assessed the self-administered, patient-reported Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire at 6 and 12 months' follow-up.

RESULTS

Initial PSQ scores correlated moderately with baseline DASH scores and slightly with symptom duration; PPTs correlated slightly with baseline DASH scores. After we accounted for confounding variables, patient-reported disability was associated with lower PPTs, higher PSQ scores, and manual labor at 6 months. These 3 factors accounted for 36% of variance in the DASH scores; however, at 12 months only the PSQ score was associated with higher DASH scores, accounting for 14% of variance.

CONCLUSIONS

Pain sensitization during the early stages of LE correlated with initial symptom severity and duration and was associated with persistently increasing disability after 1 year of nonsurgical treatment. More research is needed to show whether early identification and treatment of pain sensitization will enhance LE treatment outcomes.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic IV.

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.

OBJECTIVES

To report the effect of dry needling treatment for patients who suffer from chronic abdominal wall pain of uncertain etiology and in whom specific myofascial trigger points were identified.

METHODS

Twelve patients diagnosed with chronic abdominal wall pain were included in the study. All patients were clinically evaluated and subjected to a combination of imaging techniques. Once categorized as patients suffering from chronic abdominal wall pain, they were subjected to a thorough palpation of the abdominal wall to identify the presence of myofascial trigger points (MTrPs) over the abdominal muscles. All had MTrPs over one or more abdominal muscles either unilaterally or bilaterally. Dry Needling using a standard technique was done based on the side and localization of the myofascial trigger points. Numerical pain rating scale (NPRS) was used to measure pain before and after treatment and at the end of four months. All patients were then seen by the primary clinician and re-evaluated.

RESULTS

Eleven out of twelve patients had significant reduction with a mean difference 5.95 in NPRS in their pain levels at four months follow up. Seven patients had complete resolution of the pain. Some patients had improvement in complaints such as Dysmenorrhea, Urinary Frequency and constipation.

CONCLUSION

Dry Needling can be a useful adjunct in treating chronic abdominal wall pain especially in those patients in whom Myofascial Trigger Points in the muscles of abdomen are identified by palpation.

LEVEL OF EVIDENCE

Level 4.

Prognostic factors for the outcome of arthroscopic capsular repair of peripheral triangular fibrocartilage complex tears

BACKGROUND

Little information is available about prognostic factors of arthroscopic capsular repair for peripheral triangular fibrocartilage complex (TFCC) lesions. The purpose of this study was to analyze factors that affect the treatment outcomes of arthroscopic capsular repair for peripheral TFCC tears.

METHODS

This study retrospectively enrolled 60 patients who were treated with arthroscopic outside-in capsular repair for peripheral TFCC tears. Functional survey, including pain numeric rating scale (NRS) on an ulnar provocation test, distal radio-ulnar joint (DRUJ) stress test, Disability of the Arm, Shoulder, and Hand (DASH) score, and satisfaction with treatment, was conducted at 12-month follow-up. Patients who were enthusiastic or satisfied comprised the satisfied group, and those who were noncommittal or disappointed the dissatisfied group. Demographic, clinical, and arthroscopic findings were compared between the satisfied and dissatisfied groups.

RESULTS

The mean pain NRS and DASH scores exhibited significant clinical improvement at the 12-month follow-up. Out of the total participants, 46 were satisfied and 14 were dissatisfied about the treatment, with significantly more female subjects in the dissatisfied group than in the satisfied one. The patients in the satisfied group had a shorter duration of symptoms, were more likely to have trauma history, and exhibited positive DRUJ stress test results compared to the dissatisfied group. There were no significant group differences in age, hand dominance, work level, and the extent of ulnar plus variance. Multivariable analysis revealed that female gender, a longer duration of symptoms, or negative DRUJ stress test results were associated with an increased disability after arthroscopic TFCC repair.

CONCLUSION

Female gender, a longer duration of symptom, and a negative DRUJ stress test are associated with a higher likelihood of treatment failure after arthroscopic outside-in capsular repair of peripheral TFCC tears.

Topographic mapping of pain sensitivity of the lower back – a comparison of healthy controls and patients with chronic non-specific low back pain

Background and aims

The choice of testing site for quantitative sensory testing (QST) of pain sensitivity is important and previous studies have demonstrated patterns in pain sensitivity within discrete areas in different body regions. Some areas are characterized by a relatively high degree of spatial pain discrimination and recognizable patterns of pain referral, whilst others are not. The lumbar region is likely to have relatively low pain acuity and overlapping of pain referral. The current study was conducted to determine whether patterns of pain sensitivity (detection thresholds) could be identified in the lower back, whether differences in such patterns exist between different groups and whether such patterns could help identify a clinical source of pain and localized increased pain sensitivity.

Methods

Twenty-one patients with non-specific chronic low back pain and 21 healthy controls were tested for pressure and heat pain thresholds on 30 pre-defined locations over the mid and lower back. Topographical maps of mean pain thresholds and variability were produced, inspected visually and analyzed statistically. Between group differences in pain threshold were analyzed statistically as an indicator of widespread increased pain sensitivity. Evidence of segmental increased pain sensitivity was examined by group statistical comparison of mid-line lower range.

Results

A clear pattern of higher pain thresholds in the mid-line was evident in both groups and for both pain modalities. No discernible patterns were evident for variability within groups, but marked differences were seen between groups: variability for pressure pain thresholds appeared similar between groups, however for heat pain threshold, variability was uniformly low in the control group and uniformly high in the patient group. A highly significant (p<0.0001) difference in pain thresholds for pressure and heat was found with patients exhibiting lower thresholds than controls. No between group difference was found for mid-line lower range for either modality (p>0.05).

Conclusions

The current study supports previous findings of widespread, increased pain sensitivity in chronic non-specific low-back pain patients. It also indicates that there are discernible and similar topographical patterns of pain sensitivity in the dorsal area in both groups, but that this pattern is related to the lateral position of the test site and not the segmental level. Specific segments with increased pain sensitivity could not be identified in the patient group, which casts doubt on the utility of pressure and heat pain thresholds as indicators of the clinical source of spinal pain – at least in a population of chronic non-specific low-back pain.

Implications

In a cohort of chronic non-specific low-back pain patients and with the chosen methodology, topographical QST mapping in the lumbar region does not appear useful for identifying the spinal segment responsible for clinical pain, but it does demonstrate widespread group differences in pain sensitivity.

Efficacy of Deep Dry Needling on Latent Myofascial Trigger Points in Older Adults With Nonspecific Shoulder Pain: A Randomized, Controlled Clinical Trial Pilot Study

Background:

Nonspecific shoulder pain has a high prevalence in older adults and causes functional alterations. Furthermore, there are difficulties in establishing a clinical diagnosis, effective treatments are lacking, and little evidence has been found regarding the use of invasive physical therapy techniques in this age group.

Purpose:

To determine the efficacy of a single physical therapy intervention with deep dry needling (DDN) on latent and active myofascial trigger points (MTrPs) in older adults with nonspecific shoulder pain.

Methods:

This pilot study is a single-blind, randomized, controlled clinical trial that included 20 participants, aged 65 years and older, who were diagnosed with nonspecific shoulder pain. The study was approved by the Clinical Research Ethics Committee of the area. Participants were recruited at their homes or at a care center and were randomly assigned into either an experimental group (n = 10), which received a session of DDN on 1 active and 1 latent MTrP of the infraspinatus muscle, or a control group (n = 10), which received a session of DDN on only 1 active MTrP. A blind examiner assessed the pain intensity, pain pressure threshold on the anterior deltoid, and extensor carpi radialis brevis muscles and grip strength before, immediately after, and 1 week after the intervention.

Results:

Statistically significant differences (P < .05) in the pressure pain thresholds (PPTs) of the extensor carpi radialis brevis were found in the experimental group in both posttreatment assessments. Moreover, the effect size values (d Cohen) varied from small for grip strength (0.017-0.36) to moderate for the pain intensity (0.46-0.78) and PPT in the anterior deltoid (0.49-0.66) and to large for the PPT in the extensor carpi radialis brevis (1.06-1.58).

Conclusions:

A single physical therapy intervention with DDN on 1 latent MTrP, in conjunction with 1 active MTrP, in the infraspinatus muscle may increase the PPT of the extensor carpi radialis brevis muscle area immediately following and 1 week after the intervention in older adults with nonspecific shoulder pain.

Dry Needling on the Infraspinatus Latent and Active Myofascial Trigger Points in Older Adults With Nonspecific Shoulder Pain: A Randomized Clinical Trial

BACKGROUND AND PURPOSE

Shoulder pain is a prevalent condition in older adults. Some authors associate nonspecific shoulder pain with myofascial trigger points (MTrPs) in the infraspinatus muscle. Dry needling is recommended to relieve the MTrP pain of shoulders in the short term (<9 days). Active MTrPs dry needling improves shoulder pain and the irritability of the satellite MTrPs in the referred pain area. Nociceptive activity at a latent MTrP may influence motor activity and the sensitivity of MTrPs in distant muscles at a similar segmental level. Therefore, this study aimed to evaluate dry needling on 1 latent MTrP, in conjunction with 1 active MTrP, in the infraspinatus muscle of older adults with nonspecific shoulder pain.

METHODS

A single-center, randomized, single-blinded, controlled study (NCT02032602) was carried out. Sixty-six patients aged 65 years and older with trigger points in the ipsilateral infraspinatus of the painful shoulder were randomly assigned to (1) of (2) treatment groups. A session of dry needling on the infraspinatus was performed in (1) the most hyperalgesic active and latent MTrP or (2) only the most hyperalgesic active MTrP. The Numeric Rating Scale, the pressure pain threshold (primary outcome) on the anterior deltoid and extensor carpi radialis brevis latent MTrPs, and grip strength were assessed before, after, and 1 week after the intervention.

RESULTS

Statistically significant differences in the reduction of pain intensity (P ≤ .001; η = 0.159-0.269; d = 1.017-1.219) and the increase of pressure pain threshold (P < .001; η = 0.206-0.481; d = 0.870-1.924) were found for the (1) treatment group immediately and 1 week postintervention. Nevertheless, no statistical significant differences were found in grip strength (P >. 05; η = 0.006-0.033; d = 0.158-0.368).

CONCLUSIONS

One dry needling intervention of the latent MTrP associated with the key active MTrP of the infraspinatus reduces pain intensity and the irritability of the satellite MTrPs located in the referred pain area in the short term in older adults with nonspecific shoulder pain.

Spotlight on topographical pressure pain sensitivity maps: a review

Mechanical hyperalgesia defined as decreased pressure pain thresholds (PPTs) is commonly associated with pain. In this narrative review, we report the current state of the art within topographical pressure sensitivity maps. Such maps are based on multiple PPT assessments. The PPTs are assessed by an a priori defined grid with special focus on both spatial and temporal summation issues. The grid covers the muscle or the body region of interest using absolute or relative values determined from anatomical landmarks or anthropometric values. The collected PPTs are interpolated by Shepard or Franke and Nielson interpolation methods to create topographical pressure sensitivity maps. This new imaging technique has proven to be valuable in various disciplines including exercise physiology, neurology, physical therapy, occupational medicine, oncology, orthopedics, and sport sciences. The reviewed papers have targeted different body regions like the scalp, low back, neck-shoulder, and upper and lower extremities. The maps have delineated spatial heterogeneity in the pressure pain sensitivity underlining the different extents of pressure pain hyperalgesia in both experimentally induced and disease-associated pain conditions. Furthermore, various intervention studies have proven the utility of topographical pressure pain sensitivity maps. Topographical pressure pain sensitivity maps have contributed to revealing the efficacy of therapeutic, ergonomic, or training interventions that aim at reducing pain.

Quantitative sensory response of the SCM muscle on sustained low level activation simulating co-contractions during bruxing

OBJECTIVE

Bruxism is discussed as an etiological factor in the pathogenesis of orofacial and cervical pain. As the sternocleidomastoid muscle (SCM) is co-activated during clenching, our aim was to investigate, whether the muscle loading leads to peripheral or central sensitizations.

DESIGN

In twenty-one healthy female volunteers, somatosensory profiles of the SCM were recorded according to the test battery of the German Research Network on Neuropathic Pain (DFNS) prior to and after an isometric muscle exercise. QST comprised thermal and mechanical stimuli. A submaximal activation of the SCM (15% MVC) was kept for 10min in sitting position. In separate test sessions one month apart, one sham and one verum experiment were conducted in randomized order. During the muscle loading, the parameters cold detection threshold (CDT), mechanical pain sensitivity (MPS) and pressure pain treshold (PPT) were tested and experimental pain recorded by visual analogoue scales (VAS). All test sessions were performed during the follicular phase of the menstrual cycle (day 5), to avoid effects on pain perception. Data were analyzed with Repeated Measures ANOVA (SPSS 22.0) RESULTS: No significant changes were found during or after (sham) loading except for stimulus-response-function (SR, P=0.01) and PPT (P=0.02) in the sham test. No effect was observed in the verum experiment (P=0.12 up to 1.0).

CONCLUSION

Prolonged low level contraction of the SCM does not evoke painful sensitization. In contrast, submaximal muscle activation seems to have a protective effect corresponding to a training effect preventing sensitization.

Dry needling in a manual physiotherapy and therapeutic exercise protocol for patients with chronic mechanical shoulder pain of unspecific origin: a protocol for a randomized control trial

Background

Shoulder pain of musculoskeletal origin is the main cause of upper limb pain of non-traumatic origin. Despite being one of the most common reasons for consultation, there is no established protocol for treatment due to the complexity of its etiology. However, it has been shown that the presence of myofascial trigger points on the shoulder muscles is a common condition associated with patients suffering from shoulder pain. This protocol has been created which describes the design of a randomized controlled trial to evaluate the effectiveness of the inclusion of dry needling (DN) within a protocol of manual physiotherapy and therapeutic exercise in the treatment of chronic shoulder pain of unspecific origin.

Methods

Thirty-six participants aged 18–65 years will be recruited having mechanical chronic shoulder pain on unspecific origin and meeting the inclusion criteria. These will be randomized to one of two interventions, (i) DN, manual physiotherapy and therapeutic exercise or (ii) sham DN, manual physiotherapy and therapeutic exercise. The protocol will cover 6 weeks of treatment, with a 6-month follow-up. Our main outcome measure will be the Visual Analogue Scale for pain.

Discussion

This is the first study to combine the use of DN, manual physiotherapy and an exercise program with a 6-month follow-up, thus becoming a new contribution to the treatment of chronic shoulder pain, while new lines of research may be established to help determine the effects of DN on chronic shoulder pain and the frequency and proper dosage.

Trial registrations

International Standard Randomized Controlled Trial Number Register: ISRCTN30604244 (http://www.controlled-trials.com) 29 June 2016.

Detection of peripheral and central sensitisation at acupoints in patients with unilateral shoulder pain in Beijing: a cross-sectional matched case-control study

OBJECTIVE

To investigate the pattern of experimental pain responses at acupoints in patients with unilateral shoulder pain.

DESIGN

A cross-sectional matched study.

SETTING

Acupuncture and Moxibustion Department, Beijing Hospital of Traditional Chinese Medicine Affiliated to Capital Medical University.

PARTICIPANTS

Volunteer samples of 60 participants (30 patients with unilateral shoulder pain, 30 healthy controls).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Pressure pain thresholds (PPTs) were measured at four acupoints-namely, Tianzong (SI 11), Jianliao (SJ 14), Jianyu (LI 15) and Jianzhen (SI 9), on the painful/non-painful side in patients with unilateral shoulder pain or healthy controls, respectively. The correlations between the Peripheral Sensitisation Index (PSI) and Central Sensitisation Index (CSI) were compared.

RESULTS

Analysis showed significantly lower PPT values at acupoints on the painful side compared with the non-painful side in patients with shoulder pain (p<0.025). Meanwhile, PPTs on the non-painful side of these patients were lower than those on the ipsilateral side of healthy controls (p<0.025). No significant differences in PPT values were found between the non-acupoint of the painful/non-painful side in patients with shoulder pain and the ipsilateral side of healthy controls (p>0.05). Additionally, it was observed that the pressure pain assessment acupoints have a strong association with PSI and CSI; three acupoints, in particular, SJ 14, LI 15 and SI 9, showed a correlation with PSI and CSI.

CONCLUSION

The results suggest the presence of peripheral and central sensitisation at acupoints in participants with unilateral shoulder pain. There exists an obvious relationship among the three acupoints SJ 14, LI 15 and SI 9, which are usually chosen to treat shoulder pain. The results provide evidence for the selection of acupoints to treat shoulder pain by acupuncture.

Clinical classification in low back pain: best-evidence diagnostic rules based on systematic reviews

Background

Clinical examination findings are used in primary care to give an initial diagnosis to patients with low back pain and related leg symptoms. The purpose of this study was to develop best evidence Clinical Diagnostic Rules (CDR] for the identification of the most common patho-anatomical disorders in the lumbar spine; i.e. intervertebral discs, sacroiliac joints, facet joints, bone, muscles, nerve roots, muscles, peripheral nerve tissue, and central nervous system sensitization.

Methods

A sensitive electronic search strategy using MEDLINE, EMBASE and CINAHL databases was combined with hand searching and citation tracking to identify eligible studies. Criteria for inclusion were: persons with low back pain with or without related leg symptoms, history or physical examination findings suitable for use in primary care, comparison with acceptable reference standards, and statistical reporting permitting calculation of diagnostic value. Quality assessments were made independently by two reviewers using the Quality Assessment of Diagnostic Accuracy Studies tool. Clinical examination findings that were investigated by at least two studies were included and results that met our predefined threshold of positive likelihood ratio ≥ 2 or negative likelihood ratio ≤ 0.5 were considered for the CDR.

Results

Sixty-four studies satisfied our eligible criteria. We were able to construct promising CDRs for symptomatic intervertebral disc, sacroiliac joint, spondylolisthesis, disc herniation with nerve root involvement, and spinal stenosis. Single clinical test appear not to be as useful as clusters of tests that are more closely in line with clinical decision making.

Conclusions

This is the first comprehensive systematic review of diagnostic accuracy studies that evaluate clinical examination findings for their ability to identify the most common patho-anatomical disorders in the lumbar spine. In some diagnostic categories we have sufficient evidence to recommend a CDR. In others, we have only preliminary evidence that needs testing in future studies. Most findings were tested in secondary or tertiary care. Thus, the accuracy of the findings in a primary care setting has yet to be confirmed.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1549-6) contains supplementary material, which is available to authorized users.

Effects of Low-Load Exercise on Postneedling-Induced Pain After Dry Needling of Active Trigger Point in Individuals With Subacromial Pain Syndrome

BACKGROUND

The application of dry needling usually is associated with postneedling-induced pain. A postneedling intervention to reduce this adverse event is needed.

OBJECTIVE

To determine the effectiveness of low-load exercise on reducing postneedling-induced pain after dry needling of active trigger points (TrPs) in the infraspinatus muscle in subacromial pain syndrome.

DESIGN

A 72-hour follow-up, single-blind randomized controlled trial.

SETTING

Urban hospitals.

PARTICIPANTS

Individuals with subacromial pain syndrome (n = 90, 52% female, mean age: 35 ± 13 years) with active TrPs in the infraspinatus muscle.

INTERVENTIONS

All individuals received dry needling into the infraspinatus active TrP. Then, they were divided randomly into an experimental group, which received a single bout of low-load exercise of shoulder muscles; a placebo group, which received inactive ultrasound for 10 minutes; and a control group, which did not receive any intervention.

OUTCOME MEASURES

Numerical Pain Rating Scale (0-10 point) was administered postneedling, immediately postintervention (2 minutes), and 24, 48, and 72 hours after needling. Shoulder pain (Numerical Pain Rating Scale, 0-10) and disability (Disabilities of the Arm, Shoulder and Hand; Shoulder Pain and Disability Index) were assessed before and 72 hour after needling.

RESULTS

The 5 × 3 analysis of covariance showed that the exercise group demonstrated a larger decrease in postneedling-induced pain immediately after (P = .001), 24 hours (P = .001), and 48 hours after (P = .006) than placebo or control groups. No differences were found at 72 hours (P = .03). Similar improvements in shoulder pain (P < .001) and related disability (Disabilities of the Arm, Shoulder and Hand: P < .001; Shoulder Pain and Disability Index: P < .001) were observed 72 hours after needling, irrespective of the treatment group.

CONCLUSIONS

Low-load exercise was effective for reducing postneedling-induced pain on active TrPs in the infraspinatus muscle 24 and 48 hours after needling. The application of a postneedling intervention did not influence short-term pain and disability changes.

LEVEL OF EVIDENCE

I.

Complaints of Upper Extremity Numbness and Tingling Relieved With Dry Needling of the Teres Minor and Infraspinatus: A Case Report

Study Design Case report. Background Abnormal sensation, such as numbness or tingling, is traditionally thought to originate from neural compression. There is limited evidence to support reports of abnormal sensation arising from a trigger point. Case Description The patient was a 60-year-old woman with a primary complaint of right shoulder pain and secondary complaints of neck pain and right upper extremity numbness. Cervical spine neurological examination was unremarkable, and manual examination did not reproduce the patient's arm numbness or tingling symptoms. Compression of a trigger point in the infraspinatus and teres minor reproduced the patient's primary complaint of shoulder pain. The initial intervention included dry needling, which reproduced her upper extremity numbness. Subsequent treatment included manual therapy and exercise. Outcomes The patient was seen for a total of 3 visits, including the evaluation. Dry needling was utilized in 2 of her 3 visits. At discharge, she reported complete resolution of pain and altered sensation. Additionally, her scores on the Neck Disability Index, numeric pain-rating scale, and global rating of change exceeded the minimal clinically important difference. These outcomes were maintained at 2- and 12-month follow-up phone calls. Discussion This case report described the examination and use of dry needling in a case where the diagnosis was unclear. Clinicians may consider trigger point referral when examining patients with reports of abnormal sensation, especially when a more common cause cannot be identified. Level of Evidence Therapy, level 5. J Orthop Sports Phys Ther 2017;47(4):287-292. Epub 3 Mar 2017. doi:10.2519/jospt.2017.7055.

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.

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

OBJECTIVES

To identify the most common referred pain (ReP) pattern of the infraspinatus myofascial trigger point (MTrP) and compare its coincidence with the original ReP pattern, to verify whether there are any significant differences by sex and types of technique and to determine the observed signs and symptoms evoked by deep dry needling (DDN) and manual palpation (MPal).

DESIGN

A cohort study of patients randomized to two different examination methods (July and August 2016).

SETTINGS

Students and staff recruited from Miguel Hernandez University (Southeast Spain).

PATIENTS

One hundred thirty-three participants (70.7% women) with shoulder complaints were randomly assigned to either an MPal (n = 67) or DDN group (n = 66).

INTERVENTIONS

The same physiotherapist carried out the techniques on all participants, and the same protocol was followed for both the DDN and MPal groups. The physiotherapist did not ask participants about their pain features or other relevant issues.

OUTCOME MEASURES

Local twitch response (LTR) and ReP assessed through a visual analogue scale and features of ReP of the infraspinatus muscle.

RESULTS

The areas with the highest percentage of ReP were the front (area 3; 27.1%) and back (area 11; 21.1%) of the arm, anterior (area 4; 36.1%) and posterior (area 12; 42.1%) shoulder, and infraspinatus muscle area. DDN proved to be significantly easier than MPal in evoking an LTR (p ≤ 0.001). There were significant differences between sexes in zone 2 (p = 0.041) and no statistically significant differences were found by technique.

CONCLUSIONS

The ReP pattern of the infraspinatus muscle coincides with the original pattern described by Travell and Simons, although the neck area should be questioned. The study found no significant differences in the ReP pattern by sex and when comparing MPal with DDN of MTrP of the infraspinatus muscle. DDN proved to be significantly easier than MPal in evoking an LTR.

Comparison of hand grip strength and upper limb pressure pain threshold between older adults with or without non-specific shoulder pain

Background

There is a high prevalence of non-specific shoulder pain associated with upper limb functional limitations in older adults. The purpose of this study was to determine the minimal clinically important differences (MCID) of grip strength and pressure pain threshold (PPT) in the upper limb between older adults with or without non-specific shoulder pain.

Methods

A case-control study was carried out following the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) criteria. A sample of 132 shoulders (mean ± SD years) with (n = 66; 76.04 ± 7.58) and without (n = 66; 75.05 ± 6.26) non-specific pain were recruited. The grip strength and PPT of the anterior deltoid and extensor carpi radialis brevis (ECRB) muscles were assessed.

Results

There were statistically significant differences (mean ± SD; P-value) for anterior deltoid PPT (2.51 ± 0.69 vs 3.68 ± 0.65, kg/cm²; P < .001), ECRB PPT (2.20 ± 0.60 vs 3.35 ± 0.38 kg/cm²; P < .001) and grip strength (20.78 ± 10.94 vs 24.63 ± 9.38 kg; P = .032) between shoulders with and without non-specific pain, respectively.

Discussion

The MCID of 1.17 kg/cm², 1.15 kg/cm² and 3.84 kg were proposed for anterior deltoid PPT, ECRB PPT and grip strength, respectively, to assess the upper limb of older adults with non-specific shoulder pain after treatment. In addition, univariate and multivariate (linear regression and regression trees) analyses may be used to consider age distribution, sex, pain intensity, grip strength and PPT in older adults including clinical and epidemiological studies with non-specific shoulder pain.

Exercises and Dry Needling for Subacromial Pain Syndrome: A Randomized Parallel-Group Trial

This randomized clinical trial investigated the effectiveness of exercise versus exercise plus trigger point (TrP) dry needling (TrP-DN) in subacromial pain syndrome. A randomized parallel-group trial, with 1-year follow-up was conducted. Fifty subjects with subacromial pain syndrome were randomly allocated to receive exercise alone or exercise plus TrP-DN. Participants in both groups were asked to perform an exercise program of the rotator cuff muscles twice daily for 5 weeks. Further, patients allocated to the exercise plus TrP-DN group also received dry needling to active TrPs in the muscles reproducing shoulder symptoms during the second and fourth sessions. The primary outcome was pain-related disability assessed using the Disabilities of the Arm, Shoulder, and Hand questionnaire. Secondary outcomes included mean current pain and the worst pain experienced in the shoulder during the previous week. They were assessed at baseline, 1 week, and 3, 6, and 12 months after the end of treatment. Analysis was according to intention to treat with mixed analysis of covariance adjusted for baseline outcomes. At 12 months, 47 patients (94%) completed follow-up. Statistically larger improvements (all, P < .01) in shoulder disability was found for the exercise plus TrP-DN group at all follow-up periods (post: Δ -20.6 [95% confidence interval (CI) -23.8 to -17.4]; 3 months: Δ -23.2 [95% CI -28.3 to -18.1)]; 6 months: Δ -23.6 [95% CI -28.9 to -18.3]; 12 months: Δ -13.9 [95% CI -17.5 to -10.3]). Both groups exhibited similar improvements in shoulder pain outcomes at all follow-up periods. The inclusion of TrP-DN with an exercise program was effective for improving disability in subacromial pain syndrome. No greater improvements in shoulder pain were observed.

PERSPECTIVE

This study found that the inclusion of 2 sessions of TrP-DN into an exercise program was effective for improving shoulder pain-related disability at short-, medium-, and long-term; however, no greater improvement in shoulder pain was observed.

Intra-session absolute and relative reliability of pressure pain thresholds in the low back region of vine-workers: ffect of the number of trials

BACKGROUND

Pressure pain thresholds (PPT) are commonly used to quantify mechanical pain sensitivity of deep structures. Excellent PPT reliability has been previously reported among the low back of healthy subjects. However, there is a lack of studies assessing PPT over the low back of workers exposed to biomechanical risk factors of low back pain. Thus, the purpose of this study was threefold: (1) to evaluate the intra-session absolute and relative reliability as well as minimal detectable change (MDC) values of PPT within 14 locations covering the low back region of vine-workers and (2) to determine the number of trial required to ensure reliable PPT assessments and (3) to assess the effect of modifier factors such as gender, age, body mass index (BMI) and pain intensity on PPT reliability.

METHODS

Twenty-nine vine-workers voluntarily participated in this study. Twenty-two reported low intensity of low-back pain while seven were pain-free. PPTs were assessed among 14 anatomical locations in the lower back region. Three trials were performed on each location with an interval time of at least one minute. Reliability was assessed computing intraclass correlation coefficients (ICC), standard error of measurement (SEM) for all possible combinations between trials. Bland-Altman plots were also generated to assess potential bias in the dataset. Finally, a repeated measure analysis of variance (RM-ANOVA) with the number of trials used as within subject factor was performed on (1) PPT, (2) ICC and (3) SEM values.

RESULTS

ICC ranged from 0.86 to 0.99 for all anatomical locations and for all possible combinations between trials. SEM for comparison between trial 1-2, 2-3, 1-3 and, 1-2-3 ranged from respectively, 36.7-77.5, 27.8-77.7, 50-95.2 and, 39.3-80.8 kPa. ICC and SEM remained similar to the ones obtained for the entire population when taking modifier factors in consideration. The visual analysis of Bland-Altman plots suggested small measurement errors for all anatomical locations and for all possible combinations between trials.

CONCLUSIONS

The assessment of PPTs of the lower back among vine-workers was found to have excellent relative and absolute reliability. Moreover, reliable measurements can be equally achieved when using the mean of three PPT measurement or with the first one.

Pressure Pain Sensitivity Maps of the Neck-Shoulder Region in Breast Cancer Survivors

OBJECTIVE

The aim of the present study was to report pressure pain sensitivity topographical maps of the frontal and dorsal parts of the shoulder region, and locate the pressure pain sensitive areas in breast cancer survivors compared with matched healthy control subjects.

METHODS

Twenty-two breast cancer survivors (BCS) and 22 matched control subjects participated. A numeric pain rating scale of the neck-shoulder area and pressure pain thresholds (PPTs) was assessed bilaterally over 28 points in the frontal and dorsal neck-shoulder area. Topographical pain sensitivity maps of the upper trapezius, pectoral, and anterior deltoid areas were computed.

RESULTS

A three-way analysis of variance was carried out to evaluate the differences in PPTs. The BCS reported spontaneous neck pain (mean ± SD 3.6 ± 2.8), pain in the affected shoulder (4.3 ± 2.7), and pain in the non-affected shoulder (0.9 ± 1.8). Additionally, the BCS exhibited bilaterally lower PPTs in all the measurement points as compared with the control subjects (P < 0.05). The PPTs were lower at the superior part of the trapezius muscle (P < 0.001), the musculotendinous insertion, the anterior part of the deltoid muscle (P < 0.001), and the tendon of the pectoral muscle (P < 0.001) as compared with the control subjects.

CONCLUSIONS

The results suggest the sensitization processes in the BCS and give preliminary evidence to most sensitive areas in the superior part of the upper trapezius and musculotendinous insertion of the pectoral muscle.

Management of Postoperative Abdominal Wall Pain

Postoperative incisional pain is expected after surgery. However, when a patient is complaining of pain months after surgery, this can be a source of frustration and confusion to the patient and the surgeon. Whether the pain is a result of myofascial pain, incisional hernia, or nerve injury, understanding potential sources of abdominal wall pain can simplify this diagnostic dilemma. This chapter will focus on the diagnosis, treatment, and prevention of postsurgical abdominal wall pain.

The role of the peripheral and central nervous systems in rotator cuff disease

Rotator cuff (RC) disease is an extremely common condition associated with shoulder pain, reduced functional capacities, and impaired quality of life. It primarily involves alterations in tendon health and mechanical properties that can ultimately lead to tendon failure. RC tendon tears induce progressive muscle changes that have a negative impact on surgical reparability of the RC tendons and clinical outcomes. At the same time, a significant base of clinical data suggests a relatively weak relationship between RC integrity and clinical presentation, emphasizing the multifactorial aspects of RC disease. This review aims to summarize the potential contribution of peripheral, spinal, and supraspinal neural factors that may (1) exacerbate structural and functional muscle changes induced by tendon tear, (2) compromise the reversal of these changes during surgery and rehabilitation, (3) contribute to pain generation and persistence of pain, (4) impair shoulder function through reduced proprioception, kinematics, and muscle recruitment, and (5) help explain interindividual differences and response to treatment. Given the current clinical and scientific interest in peripheral nerve injury in the context of RC disease and surgery, we carefully reviewed this body of literature with a particular emphasis on suprascapular neuropathy that has generated a large number of studies in the past decade. Within this process, we highlight the gaps in current knowledge and suggest research avenues for scientists and clinicians.